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Rues S, Herpel C, Ilani A, Schmitt C, Rammelsberg P, Schwindling FS. Effect of firing time and wall thickness on the biaxial flexural strength of 3D-printed zirconia. Dent Mater 2024; 40:484-492. [PMID: 38155019 DOI: 10.1016/j.dental.2023.12.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 12/13/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023]
Abstract
OBJECTIVES To evaluate the effect of accelerated firing on 3D-printed zirconia. METHODS To check if formulae provided by ISO 6872 can be extended to thin samples, finite element analyses were carried out in advance of fabricating 3-mol% yttria-stabilized tetragonal zirconia polycrystal discs by milling and by 3D-printing. Four groups (n = 38 each) of 3D-printed specimens were produced with two nominal thicknesses (0.6 mm and 1.2 mm) and two firing strategies (long: 51 h, accelerated: 14.5 h). In the milled group (thickness 1.2 mm, n = 30), a standard firing program (9.8 h) was selected. Biaxial flexural strength tests were applied and mean strength, characteristic strength, and Weibull modulus were calculated for each group. Differences were analyzed using Welch ANOVA and Dunnett-T3 post-hoc tests. RESULTS Maximum tensile stresses occurring during biaxial strength testing can be calculated according to ISO 6872 for thin samples with b > 0.3 mm. Variability of measured strengths values was smaller for milled zirconia compared with 3D-printed zirconia. The 1.2-mm-thick 3D-printed samples had significantly decreased strength after accelerated firing than after long firing. However, for the 0.6-mm-thick samples, comparable mean biaxial strength values of about 1000 MPa were measured for both firing protocols. SIGNIFICANCE At the moment, long fabrication time for zirconia restorations is a major drawback of 3D-printing when compared with milling technology. This investigation showed that the strength of 0.6-mm-thick zirconia discs fabricated by 3D-printing was not impaired by accelerated firing. Thus, overnight firing of thin-walled 3D-printed zirconia restorations could be possible.
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Affiliation(s)
- Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany.
| | - Christopher Herpel
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Ali Ilani
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Clemens Schmitt
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany; Department of Prosthetic Dentistry, Medical University Innsbruck, Innsbruck, Austria
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Franz Sebastian Schwindling
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany; Department of Prosthetic Dentistry, Medical University Innsbruck, Innsbruck, Austria
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Rues S, Tasaka A, Fleckenstein I, Yamashita S, Rammelsberg P, Boehm S, Schwindling FS. Fit and Retention of Cobalt-Chromium Removable Partial Denture Frameworks Fabricated with Selective Laser Melting. J Funct Biomater 2023; 14:416. [PMID: 37623661 PMCID: PMC10456016 DOI: 10.3390/jfb14080416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 07/28/2023] [Accepted: 08/04/2023] [Indexed: 08/26/2023] Open
Abstract
PURPOSE To evaluate fit and retention of cobalt-chromium removable partial denture (RPD) frameworks fabricated with selective laser melting (SLM). METHODS Three types of framework for clasp-retained RPDs were virtually designed and fabricated using SLM (n = 30). For comparison, 30 additional frameworks were produced using conventional lost-wax casting. A biomechanical model was created, incorporating extracted teeth mounted on flexible metal posts. Using this model, horizontal constraint forces resulting from a misfit were measured using strain gauges, while vertical forces were not recorded. The constraint force components and resultant forces were determined for all abutment teeth, and the maximum retention force during RPD removal from the model was also assessed. For statistical evaluation, the two fabrication methods were analyzed by calculating the means and standard deviations. RESULTS The average horizontal constraint forces showed similar values for both fabrication methods (SLM: 3.5 ± 1.0 N, casting: 3.4 ± 1.6 N). The overall scatter of data for cast RPDs was greater compared to those fabricated using SLM, indicating a better reproducibility of the SLM process. With regard to retention, the intended retention force of 5-10 N per abutment tooth was not attained in one of the cast groups, while it was consistently achieved in all SLM groups. CONCLUSIONS This in vitro study found that SLM is a promising option for the manufacture of cobalt-chromium RPD frameworks in terms of fit and retention.
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Affiliation(s)
- Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Akinori Tasaka
- Department of Removable Prosthodontics, Tokyo Dental College, Tokyo 101-0061, Japan
| | - Isabella Fleckenstein
- Department of Prosthodontics, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Shuichiro Yamashita
- Department of Removable Prosthodontics, Tokyo Dental College, Tokyo 101-0061, Japan
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Sophia Boehm
- Department of Prosthodontics, Heidelberg University Hospital, 69120 Heidelberg, Germany
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Liebermann A, Schultheis A, Faber F, Rammelsberg P, Rues S, Schwindling FS. Impact of post printing cleaning methods on geometry, transmission, roughness parameters, and flexural strength of 3D-printed zirconia. Dent Mater 2023; 39:625-633. [PMID: 37179237 DOI: 10.1016/j.dental.2023.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 04/12/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023]
Abstract
OBJECTIVE To analyze the impact of different post printing cleaning methods on geometry, transmission, roughness parameters, and flexural strength of additively manufactured zirconia. METHODS Disc-shaped specimens (N = 100) were 3D-printed from 3 mol%-yttria-stabilized zirconia (material: LithaCon 3Y 210; printer: CeraFab 7500, Lithoz) and were cleaned with five different methods (n = 20): (A) 25 s of airbrushing with the dedicated cleaning solution (LithaSol 30®, Lithoz) and 1-week storage in a drying oven (40 °C); (B) 25 s airbrushing (LithaSol 30®) without drying oven; (C) 30 s ultrasonic bath (US) filled with Lithasol30®; (D) 300 s US filled with LithaSol 30®; (E) 30 s US filled with LithaSol 30® followed by 40 s of airbrushing (LithaSol 30®). After cleaning, the samples were sintered. Geometry, transmission, roughness (Ra, Rz), characteristic strengths (σ0), and Weibull moduli (m) were analyzed. Statistical analyses were performed using Kolmogorov-Smirnov-, t-, Kruskal-Wallis-, and Mann-Whitney-U-tests (α < 0.05). RESULTS Short US (C) resulted in the thickest and widest samples. Highest transmission was found for US combined with airbrushing (E, p ≤ 0.004), followed by D and B (same range, p = 0.070). Roughness was lowest for US combined with airbrushing (E, p ≤ 0.039), followed by A and B (same range, p = 0.172). A (σ0 = 1030 MPa, m = 8.2), B (σ0 = 1165 MPa, m = 9.8), and E (σ0 = 1146 MPa, m = 8.3) were significantly stronger (p < 0.001) and substantially more reliable than C (σ0 = 480 MPa, m = 1.9) and D (σ0 = 486 MPa, m = 2.1). SIGNIFICANCE For 3D-printed zirconia, cleaning strategy selection is important. Airbrushing (B) and short US combined with airbrushing (E) were most favorable regarding transmission, roughness, and strength. Ultrasonic cleaning alone was ineffective (short duration) or detrimental (long duration). Strategy E could be particularly promising for hollow or porous structures.
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Affiliation(s)
- A Liebermann
- Department of Prosthetic Dentistry, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany.
| | - A Schultheis
- Department of Prosthetic Dentistry, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - F Faber
- Department of Prosthetic Dentistry, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany
| | - P Rammelsberg
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - S Rues
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - F S Schwindling
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany; Department of Prosthetic Dentistry, Medical University Innsbruck, Innsbruck, Austria
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Herpel C, Schwindling FS, Rammelsberg P, Tesarz J. A Functional Problem - On a Linguistic Ambiguity in Dentistry. J Oral Rehabil 2023. [PMID: 37223999 DOI: 10.1111/joor.13518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 05/04/2023] [Accepted: 05/19/2023] [Indexed: 05/26/2023]
Affiliation(s)
- Christopher Herpel
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Peter Rammelsberg
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - Jonas Tesarz
- Department of General Internal Medicine and Psychosomatics, Heidelberg University Hospital, Heidelberg, Germany
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Herpel C, Held T, Labis C, Christ L, Lang K, Regnery S, Eichkorn T, Lentz-Hommertgen A, Jaekel C, Moratin J, Semmelmayer K, Moutsis TT, Plath K, Ristow O, Freudlsperger C, Adeberg S, Debus J, Rammelsberg P, Schwindling FS. Oral Sequelae after Head and Neck Radiotherapy: RCT Comparing 3D-Printed Tissue Retraction Devices with Conventional Dental Splints. J Clin Med 2023; 12:jcm12082789. [PMID: 37109126 PMCID: PMC10146966 DOI: 10.3390/jcm12082789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 04/02/2023] [Accepted: 04/04/2023] [Indexed: 04/29/2023] Open
Abstract
OBJECTIVES To evaluate oral sequelae after head and neck radiotherapy (RT) when using two different types of intraoral appliances. Thermoplastic dental splints (active control) protect against backscattered radiation from dental structures. Semi-individualized, 3D-printed tissue retraction devices (TRDs, study group) additionally spare healthy tissue from irradiation. MATERIALS AND METHODS A total of 29 patients with head and neck cancer were enrolled in a randomized controlled pilot trial and allocated to receive TRDs (n = 15) or conventional splints (n = 14). Saliva quality and quantity (Saliva-Check, GC), taste perception (Taste strips, Burghart-Messtechnik), and oral disability (JFLS-8, OHIP-14, maximum mouth opening) were recorded before and 3 months after RT start. Radiotherapy target volume, modality, total dose, fractionation, and imaging guidance were case-dependent. To evaluate intra-group developments between baseline and follow-up, nonparametric Wilcoxon tests were performed. Mann-Whitney-U tests were applied for inter-group comparisons. RESULTS At follow-up, taste perception was unimpaired (median difference in the total score; TRDs: 0, control: 0). No significant changes were found regarding oral disability. Saliva quantity (stimulated flow) was significantly reduced with conventional splints (median -4 mL, p = 0.016), while it decreased insignificantly with TRDs (median -2 mL, p = 0.07). Follow-up was attended by 9/15 study group participants (control 13/14). Inter-group comparisons showed no significant differences but a tendency towards a better outcome for disability and saliva quality in the intervention group. CONCLUSION Due to the small cohort size and the heterogeneity of the sample, the results must be interpreted with reservation. Further research must confirm the positive trends of TRD application. Negative side-effects of TRD application seem improbable.
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Affiliation(s)
- Christopher Herpel
- Department of Prosthodontics, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Thomas Held
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany
- National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
| | - Christos Labis
- Department of Prosthodontics, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Leo Christ
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Kristin Lang
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany
- National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
| | - Sebastian Regnery
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany
- National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
| | - Tanja Eichkorn
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany
- National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
| | - Adriane Lentz-Hommertgen
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany
| | - Cornelia Jaekel
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany
| | - Julius Moratin
- Department of Oral and Maxillofacial Surgery, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Karl Semmelmayer
- Department of Oral and Maxillofacial Surgery, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Tracy Thecla Moutsis
- Department of Otorhinolaryngology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Karim Plath
- Department of Otorhinolaryngology, University of Heidelberg, 69120 Heidelberg, Germany
| | - Oliver Ristow
- Department of Oral and Maxillofacial Surgery, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Christian Freudlsperger
- Department of Oral and Maxillofacial Surgery, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Sebastian Adeberg
- Department of Radiation Oncology, Marburg Ion-Beam Therapy Center (MIT), Marburg University Hospital, 35043 Marburg, Germany
- Department of Radiation Oncology, Marburg University Hospital, 35043 Marburg, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany
- National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
- Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Heidelberg Ion-Beam Therapy Center (HIT), 69120 Heidelberg, Germany
- German Cancer Consortium (DKTK), Partner Site Heidelberg, German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, 69120 Heidelberg, Germany
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Longarino FK, Herpel C, Tessonnier T, Mein S, Ackermann B, Debus J, Schwindling FS, Stiller W, Mairani A. Dual-energy CT-based stopping power prediction for dental materials in particle therapy. J Appl Clin Med Phys 2023:e13977. [PMID: 37032540 PMCID: PMC10402687 DOI: 10.1002/acm2.13977] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/23/2023] [Accepted: 03/17/2023] [Indexed: 04/11/2023] Open
Abstract
Radiotherapy with protons or light ions can offer accurate and precise treatment delivery. Accurate knowledge of the stopping power ratio (SPR) distribution of the tissues in the patient is crucial for improving dose prediction in patients during planning. However, materials of uncertain stoichiometric composition such as dental implant and restoration materials can substantially impair particle therapy treatment planning due to related SPR prediction uncertainties. This study investigated the impact of using dual-energy computed tomography (DECT) imaging for characterizing and compensating for commonly used dental implant and restoration materials during particle therapy treatment planning. Radiological material parameters of ten common dental materials were determined using two different DECT techniques: sequential acquisition CT (SACT) and dual-layer spectral CT (DLCT). DECT-based direct SPR predictions of dental materials via spectral image data were compared to conventional single-energy CT (SECT)-based SPR predictions obtained via indirect CT-number-to-SPR conversion. DECT techniques were found overall to reduce uncertainty in SPR predictions in dental implant and restoration materials compared to SECT, although DECT methods showed limitations for materials containing elements of a high atomic number. To assess the influence on treatment planning, an anthropomorphic head phantom with a removable tooth containing lithium disilicate as a dental material was used. The results indicated that both DECT techniques predicted similar ranges for beams unobstructed by dental material in the head phantom. When ion beams passed through the lithium disilicate restoration, DLCT-based SPR predictions using a projection-based method showed better agreement with measured reference SPR values (range deviation: 0.2 mm) compared to SECT-based predictions. DECT-based SPR prediction may improve the management of certain non-tissue dental implant and restoration materials and subsequently increase dose prediction accuracy.
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Affiliation(s)
- Friderike K Longarino
- Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Christopher Herpel
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Thomas Tessonnier
- Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany
- Translational Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
| | - Stewart Mein
- Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany
- Translational Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
| | | | - Jürgen Debus
- Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
- German Cancer Consortium (DKTK), Core Center Heidelberg, Heidelberg, Germany
| | | | - Wolfram Stiller
- Diagnostic & Interventional Radiology (DIR), Heidelberg University Hospital, Heidelberg, Germany
| | - Andrea Mairani
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Heidelberg Ion Beam Therapy Center (HIT), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
- Medical Physics, National Center of Oncological Hadrontherapy (CNAO), Pavia, Italy
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Christopher H, Kykal J, Rues S, Schwindling FS, Rammelsberg P, Eberhard L. Thermo-flexible resin for the 3D printing of occlusal splints: a randomized pilot trial. J Dent 2023; 133:104514. [PMID: 37031885 DOI: 10.1016/j.jdent.2023.104514] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 04/04/2023] [Accepted: 04/05/2023] [Indexed: 04/11/2023] Open
Abstract
OBJECTIVES To compare the clinical performance of occlusal splints printed from thermo-flexible resin with milled splints. METHODS A parallel two-arm pilot trial was initiated. Forty-seven patients (n women=38) were recruited from a tertiary care center and randomized using an online tool (sealed envelope). Inclusion criterion was an indication for treatment with a centric relation occlusal splint due to bruxism or any form of painful temporomandibular disorder. Patients were excluded if they were younger than 18 years, unable to attend follow-up appointments, or required another type of splint therapy. Patients received either, a 3D-printed (intervention group, V-print splint comfort, VOCO) or a milled splint (control group, ProArt CAD splint, Ivoclar). Construction software Ceramill M-splint (AmannGirrbach), 3D-printer MAX UV 385 (Asiga) and milling unit PrograMill PM7 (Ivoclar) were used. Follow-up assessments were conducted after 2 weeks and 3 months. Outcome measures were survival, adherence, technical complications, patient satisfaction on a 10-point Likert scale, and maximum wear using superimposition of optical scans. RESULTS After 3 months, 20/23 intervention group and 18/24 control group participants were assessed. All splints survived. Minor complications were small crack formations on 6 printed and 4 milled splints. Mean patient satisfaction was 8 (SD 1.7) for printed, and 8.1 (SD 2.3) for milled splints (r= .1, p=.52). Median maximum wear was highly dispersed with 153 (IQR 140) in posterior and 195 (IQR 537) in frontal segments of printed, and 96 (IQR 78) respectively 123 (IQR 155) of milled splints, (both: r= .31, p=.084). CONCLUSIONS Within the limitations of a pilot trial, 3D-printed and milled splints performed similarly in terms of patient satisfaction, complication rates and wear behavior. CLINICAL SIGNIFICANCE Thermo-flexible material was proposed for 3D printing of occlusal splints to overcome mechanical weaknesses of previously available resins. This randomized pilot study provides evidence that this material is a viable alternative to milled splints for at least three months of clinical use. Further evidence on long-term use should be obtained.
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Affiliation(s)
- Herpel Christopher
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany.
| | - Jana Kykal
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany
| | - Stefan Rues
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany
| | | | - Peter Rammelsberg
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany
| | - Lydia Eberhard
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany
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Miotk N, Schwindling FS, Zidan M, Juerchott A, Rammelsberg P, Hosseini Z, Nittka M, Heiland S, Bendszus M, Hilgenfeld T. Reliability and accuracy of intraoral radiography, cone beam CT, and dental MRI for evaluation of peri-implant bone lesions at zirconia implants - an ex vivo feasibility study. J Dent 2023; 130:104422. [PMID: 36649822 DOI: 10.1016/j.jdent.2023.104422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Revised: 01/09/2023] [Accepted: 01/11/2023] [Indexed: 01/15/2023] Open
Abstract
OBJECTIVES To determine the reliability and accuracy of intraoral radiography (IR), cone-beam-computed tomography (CBCT), and dental magnetic resonance imaging (dMRI) in measuring peri‑implant bone defects around single zirconia implants. METHODS Twenty-four zirconia implants were inserted in bovine ribs with various peri‑implant defect sizes and morphologies. True defect extent was measured without implant in CBCT. Defects were measured twice in IR, CBCT, and dMRI with the inserted implant by three experienced readers. Reliability was assessed by ICC, accuracy by the Friedman test, and post-hoc-Tukey's test. RESULTS A comparable good to excellent intra- and inter-reader reliability was observed for all modalities (intra-/inter-rater-CC range for IR; CBCT; dMRI: 0.81-0.91/0.79;0.87-0.97/0.96;0.87-0.95/0.94). Accuracy was generally high, with mean errors below 1 mm in all directions. However, measuring defect depth in the mesiodistal direction was significantly more accurate in dMRI (0.65 ± 0.38 mm) compared to IR (2.71 ± 1.91 mm), and CBCT (1.98 ± 1.97 mm), p-values ≤ 0.0001 respectively ≤ 0.01. CONCLUSIONS Osseous defects around zirconia implants can be reliably measured in IR/CBCT/dMRI in the mesiodistal directions. In addition, CBCT and dMRI allow assessment of the buccolingual directions. dMRI provides a comparable accuracy in all directions, except for the mesiodistal defect depth, where it outperforms IR and CBCT.
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Affiliation(s)
- Nikolai Miotk
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, Heidelberg 69120, Germany.
| | - Franz Sebastian Schwindling
- Department of Prosthodontics, Heidelberg University Hospital, Im Neuenheimer Feld 400, Heidelberg 69120, Germany.
| | - Moussa Zidan
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, Heidelberg 69120, Germany.
| | - Alexander Juerchott
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, Heidelberg 69120, Germany.
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Im Neuenheimer Feld 400, Heidelberg 69120, Germany.
| | - Zahra Hosseini
- MRI-sequence developer, Magnetic Resonance R&D Collaborations, Siemens Medical Solutions, Atlanta, 3139 Mae Ave NE, Atlanta, GA - Georgia 30319, United States.
| | - Mathias Nittka
- MRI-sequence developer, Magnetic Resonance, Siemens Healthcare GmbH, Erlangen, Enkestraße 127, Erlangen 91052, Germany.
| | - Sabine Heiland
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, Heidelberg 69120, Germany.
| | - Martin Bendszus
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, Heidelberg 69120, Germany.
| | - Tim Hilgenfeld
- Department of Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, Heidelberg 69120, Germany.
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Rues S, Zehender N, Zenthöfer A, Bömicke W, Herpel C, Ilani A, Erber R, Roser C, Lux CJ, Rammelsberg P, Schwindling FS. Fit of anterior restorations made of 3D-printed and milled zirconia: An in-vitro study. J Dent 2023; 130:104415. [PMID: 36640843 DOI: 10.1016/j.jdent.2023.104415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 12/23/2022] [Accepted: 01/10/2023] [Indexed: 01/13/2023] Open
Abstract
OBJECTIVES To evaluate the fit of zirconia veneers made by either 3D printing or milling. METHODS A typodont maxillary central incisor was prepared for a 0.5-mm-thick veneer and was reproduced 36 times from resin. Restorations were designed with a 20-µm-wide marginal and a 60-µm-wide internal cement gap, and were made from 3D-printed zirconia (LithaCon 3Y 210, Lithoz, n = 24) and milled zirconia (Cercon ht, DentsplySirona, n = 12). For milled zirconia, a drill compensation was needed to give the milling bur access to the intaglio surface. The restorations were cemented, cross-sectioned, and the cement gap size was analyzed by two raters. Inter-rater reliability was studied at 12 3D-printed veneers (intraclass correlation coefficient, ICC, mixed model, absolute agreement). Twelve remaining 3D-printed restorations were compared with 12 milled restorations regarding fit at three locations: marginally, labially, and at the incisal edge (Mann-Whitney U-tests, α<0.05). RESULTS Inter-rater reliability was excellent, with an ICC single-measure coefficient of 0.944 (95%-confidence interval: [0.907; 0.966]). Gap sizes (mean ± SD / maximum) were 55 ± 9 / 143 µm at the margins, 68 ± 14 / 130 µm labially, and 78 ± 19 / 176 µm at the incisor edge for 3D-printed veneers. For milled veneers, gap sizes were 44 ± 11 / 141 µm at the margins, 85 ± 19 / 171 µm labially, and 391 ± 26 / 477 µm at the incisor edge. At the margins, the milled veneers outperformed the 3D-printed restorations (p = 0.011). The cement gap at the incisor edge was significantly smaller after 3D printing (p < 0.001). CONCLUSIONS 3D-printed zirconia restorations showed clinically acceptable mean marginal gaps below 100 µm. Because drill compensation could be omitted with 3D printing, the fit at the sharp incisal edge was significantly tighter than with milling. CLINICAL SIGNIFICANCE The fit of 3D-printed ceramic anterior restorations meets clinical standards. In addition, 3D printing is associated with a greater geometrical freedom than milling. With regard to fit this feature allows tighter adaptation even after minimally invasive preparation.
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Affiliation(s)
- Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Nathalie Zehender
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Andreas Zenthöfer
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Wolfgang Bömicke
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Christopher Herpel
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Ali Ilani
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Ralf Erber
- Department of Orthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Christoph Roser
- Department of Orthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Christopher J Lux
- Department of Orthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
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Herpel C, Drusko A, Schwindling FS, Rammelsberg P, Tesarz J. Head and Neck Pain Drawing Area Correlates With Higher Psychosocial Burden But Not With Joint Dysfunction in Temporomandibular Disorders: A Cross-Sectional Study. J Pain 2023:S1526-5900(23)00018-4. [PMID: 36682594 DOI: 10.1016/j.jpain.2023.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Revised: 12/31/2022] [Accepted: 01/12/2023] [Indexed: 01/22/2023]
Abstract
Head and neck pain drawings have been introduced as part of the diagnostic gold standard for temporomandibular disorders (TMD). We aimed to quantify the spatial extent of pain in TMD patients and to analyze its association with further clinical findings. In a cross-sectional study, 90 patients (median age = 38 years; n women = 68) were diagnosed according to the DC/TMD. Intra-articular disorders were either confirmed or rejected by magnetic resonance imaging. The patients shaded all painful areas in a sketch of the left and right side of a face. A grid template was placed over the drawings and each region that contained markings was scored as painful. The correlation between the calculated area and the psychosocial variables (DC/TMD axis II) as well as the influence of pain lateralization were investigated using Spearman correlation, Mann-Whitney-U and chi-square tests. Pain affected all facial areas but concentrated on the regions of the temporomandibular joint and masseter origin. Thirty-nine percent reported purely unilateral pain, which was associated with structural TMJ findings in 77% of cases. Individuals with bilateral pain and those with greater spatial spread of pain had significantly higher scores on all axis II variables, except for functional limitation of the jaw. PERSPECTIVE: Head and neck pain drawings can contribute to a stratification of TMD patients. A greater extent of pain as well as pain bilateralization is associated with higher levels of emotional distress, pain chronicity and somatization, but not with functional impairment. Unilateral reporting of pain is associated with more intra-articular disorders.
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Affiliation(s)
- Christopher Herpel
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany.
| | - Armin Drusko
- Department of General Internal Medicine and Psychosomatics, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Jonas Tesarz
- Department of General Internal Medicine and Psychosomatics, Heidelberg University Hospital, Heidelberg, Germany
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11
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Hilgenfeld T, Saleem MA, Schwindling FS, Ludwig U, Hövener JB, Bock M, Flügge T, Eisenbeiss AK, Nittka M, Mente J, Jende JME, Heiland S, Bendszus M, Juerchott A. High-Resolution Single Tooth MRI With an Inductively Coupled Intraoral Coil-Can MRI Compete With CBCT? Invest Radiol 2022; 57:720-727. [PMID: 35640007 DOI: 10.1097/rli.0000000000000890] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES The aims of this study were to quantify T1/T2-relaxation times of the dental pulp, develop a realistic tooth model, and compare image quality between cone-beam computed tomography (CBCT) and high-resolution magnetic resonance imaging (MRI) of single teeth using a wireless inductively coupled intraoral coil. METHODS T1/T2-relaxometry was performed at 3 T in 10 healthy volunteers (283 teeth) to determine relaxation times of healthy dental pulp and develop a realistic tooth model using extracted human teeth. Eight MRI sequences (DESS, CISS, TrueFISP, FLASH, SPACE, TSE, MSVAT-SPACE, and UTE) were optimized for clinically applicable high-resolution imaging of the dental pulp. In model, image quality of all sequences was assessed quantitatively (contrast-to-noise ratio) and qualitatively (visibility of anatomical structures and extent of susceptibility artifacts using a 5-point scoring scale). Cone-beam computed tomography served as the reference modality for qualitative assessment. Statistical analysis was performed using 2-way analysis of variance, Fisher exact test, and Cohen κ. RESULTS In vivo, relaxometry of dental pulps revealed T1/T2 relaxation times at 3 T of 738 ± 100/171 ± 36 milliseconds. For all sequences, an isotropic resolution of (0.21 mm) 3 was achieved, with acquisition times ranging from 6:19 to 8:02 minutes. In model, the highest contrast-to-noise ratio values were observed for UTE, followed by TSE and CISS. The best image/artifact quality, however, was found for DESS (mean ± SD: 1.3 ± 0.3/2.2 ± 0.0), FLASH (1.5 ± 0.3/2.4 ± 0.1), and CISS (1.5 ± 0.4/2.5 ± 0.1), at a level comparable to CBCT (1.2 ± 0.3/2.1 ± 0.1). CONCLUSIONS Optimized MRI protocols using an intraoral coil at 3 T can achieve an image quality comparable to reference modality CBCT within clinically applicable acquisition times. Overall, DESS revealed the best results, followed by FLASH and CISS.
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Affiliation(s)
| | | | | | - Ute Ludwig
- Department of Radiology, Medical Physics, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg
| | - Jan-Bernd Hövener
- Section Biomedical Imaging, Department of Radiology and Neuroradiology, University Medical Center Schleswig-Holstein, Kiel University, Kiel
| | - Michael Bock
- Department of Radiology, Medical Physics, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg
| | - Tabea Flügge
- Department of Oral and Maxillofacial Surgery, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin
| | - Anne-Katrin Eisenbeiss
- Department of Oral and Maxillofacial Surgery, University Medical Center Schleswig-Holstein, Christian-Albrechts-University, Kiel
| | | | - Johannes Mente
- Division of Endodontics and Dental Traumatology, Department of Conservative Dentistry, Heidelberg University Hospital, Heidelberg, Germany
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12
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Zenthöfer A, Schwindling FS, Schmitt C, Ilani A, Zehender N, Rammelsberg P, Rues S. Strength and reliability of zirconia fabricated by additive manufacturing technology. Dent Mater 2022; 38:1565-1574. [PMID: 35933222 DOI: 10.1016/j.dental.2022.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 06/29/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022]
Abstract
OBJECTIVES To test strength and reliability of 3D printed compared to milled zirconia. METHODS Cylindrical specimens were fabricated from milled (group G1; e.max ZirCAD LT) and from 3D printed (group G2; LithaCon 3Y 230) 3-mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP). While G1 and G2 were sintered in one step, a further series (G3) of 3D printed 3Y-TZP was sintered in two steps including intermediate color infiltration. In each group, two different conditioning strategies were applied (n ≥ 20 samples/subgroup): (1) final polishing with #1200 diamond discs according to ISO 6872, and (2) final polishing with #220 diamond discs resulting in imperfectly polished surfaces. All samples were tested to fracture with a universal testing device (cross-head speed: 1 mm/min). Characteristic strengths and Weibull moduli were calculated. Effects were analyzed by means of either ANOVA (homocedastic data) or Welch ANOVA (heterocedastic data). RESULTS For samples conditioned according to ISO 6872, mean flexural strengths were 1462 ± 105 MPa (G1), 1369 ± 280 MPa (G2), and 1197 ± 317 MPa (G3). For the imperfectly polished subgroups, strength values were 1461 ± 121 MPa (G1), 1349 ± 332 MPa (G2), and 1271 ± 272 MPa (G3). Although all groups showed high mean strength values, the reliability of milled zirconia (Weibull moduli 14 < m <16) outperformed that of the 3D-printed material (3 < m <6). SIGNIFICANCE Even after color infiltration in a partially sintered state, the tested 3D printed zirconia exceeded the ISO flexural strength criteria for all types of fixed ceramic restorations by far (800 MPa for class 6, ISO 6872), indicating its high potential for clinical use. Further optimization of the internal material structure after sintering might improve the reliability of 3D printed zirconia which is currently inferior to that of milled zirconia.
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Affiliation(s)
- Andreas Zenthöfer
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Franz Sebastian Schwindling
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Clemens Schmitt
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Ali Ilani
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Nathalie Zehender
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Stefan Rues
- Department of Prosthodontics, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany.
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13
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Tasaka A, Rues S, Schwindling FS, Rammelsberg P, Yamashita S. Retentive force of conical crowns combining zirconia and fiber-reinforced composite. J Dent 2022; 124:104222. [PMID: 35820502 DOI: 10.1016/j.jdent.2022.104222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Revised: 07/05/2022] [Accepted: 07/08/2022] [Indexed: 10/17/2022] Open
Abstract
PURPOSE This study investigated the retentive force of conical crowns combining zirconia primary and fiber-reinforced composite (FRC) secondary crowns and their changes due to aging. METHODS Zirconia primary crowns were produced with a convergence angle of 3°. Thirty-two secondary crowns were milled from FRC and divided into two groups (n = 16/group) based on the polishing method of the secondary crown inner surfaces: diamond paste (Group 1) and silicone points (Group 2). After fitting the secondary crowns with different fitting forces (F), loosening forces (L) were determined. Tests were repeated after an occlusal stop (OS) was added to the secondary crown and artificial aging (10,000 insertion/removal cycles). Data were compared using the Wilcoxon and Mann-Whitney U tests. RESULTS Crowns without an OS showed L/F ratios of 0.4586 (Group 1) and 0.4104 (Group 2). With an OS, maximum retention was not significantly affected by the polishing method and could be limited to Lmax = 19.31±7.77 N (Group 1) and Lmax = 16.12±5.92 N (Group 2). CONCLUSIONS These findings suggest that the combination of conical zirconia primary and FRC secondary crowns can obtain acceptable retentive forces that are not affected by aging if the inner surfaces are polished with diamond paste. OS generation could limit maximum retention, but should be adjusted if the target value of 10 N is not to be exceeded. With a change of the convergence angle to 4°, L/F values for crowns without an OS would be close to 1/3, which is considered ideal for conical crowns. CLINICAL SIGNIFICANCE The combination of zirconia primary crowns and FRC secondary crowns was found feasible to ensure the required retention for clinical use over a long time span. Furthermore, it offers an alternative to metal-based restorations while ensuring high levels of biocompatibility and esthetics.
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Affiliation(s)
- Akinori Tasaka
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany; Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan.
| | - Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Shuichiro Yamashita
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo, Japan
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14
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Passia N, Ali S, Behrendt C, Fritzer E, Kohal RJ, Luthardt RG, Maltzahn NFV, Rädel M, Reissmann DR, Schwindling FS, Wolfart S, Kern M. Single mandibular implant study - chewing efficiency - 5-year results from a randomized clinical trial using two different implant loading protocols. J Prosthodont Res 2022; 66:610-617. [PMID: 35197416 DOI: 10.2186/jpr.jpr_d_21_00216] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE To investigate the chewing efficiency of edentulous patients wearing complete dentures, treated with a single implant in the mandible, placed underneath the existing mandibular dentures, using two different loading protocols (immediate loading or conventional loading), over an observation period of 5 years. METHODS One-hundred and fifty-eight (158) edentulous seniors aged 60-89 years received an implant in the midline of the lower jaw and were randomized either to the immediate loaded group A (n=81) or the conventional loaded group B (n=77). Chewing efficiency was obtained before treatment, one month after implant placement during the submerged healing phase (only group B) and 1, 4, 12, 24 and 60 months after implant loading. RESULTS After 5 years, chewing tests from 89 patients (45 in the immediate loading group and 44 in the conventional loading group) were available for every recall visit and thus statistically analyzed. The chewing efficiency increased over time in both groups. A significant increase was observed up to 4 months after loading (p≤0.05). Later, chewing efficiency further increased, but not significantly. Between the two loading protocols, chewing efficiency did not differ significantly (p>0.05) at any follow-up investigation. CONCLUSION A single mandibular implant placed underneath existing mandibular dentures improves chewing efficiency of edentulous patients significantly over an observation period of 5 years, irrespective of the loading protocol.
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Affiliation(s)
- Nicole Passia
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Germany.,Department of Prosthetic Dentistry, Faculty of Medicine Carl Gustav Carus, TU Dresden, Germany
| | - Shurouk Ali
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Germany
| | - Christoph Behrendt
- Department of Prosthodontics, Gerodontology and Biomaterials, Greifswald University Hospital, Germany
| | - Elfriede Fritzer
- Center for Clinical Studies, Christian-Albrechts University at Kiel, Germany
| | - Ralf Joachim Kohal
- Medical Center - University of Freiburg, Center for Dental Medicine, Department of Prosthetic dentistry, Faculty of Medicine, University of Freiburg, Germany
| | - Ralph G Luthardt
- Center of Dentistry, Department of Prosthetic Dentistry, Ulm University Hospital, Germany
| | | | - Michael Rädel
- Department of Prosthetic Dentistry, Faculty of Medicine Carl Gustav Carus, TU Dresden, Germany
| | - Daniel R Reissmann
- Center for Dental and Oral Medicine, Department of Prosthetic Dentistry, University Medical Center Hamburg-Eppendorf, Germany
| | | | - Stefan Wolfart
- Department of Prosthodontics and Biomaterials, Medical Faculty, RWTH Aachen University, Germany
| | - Matthias Kern
- Department of Prosthodontics, Propaedeutics and Dental Materials, School of Dentistry, Christian-Albrechts University at Kiel, Germany
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15
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Herpel C, Rammelsberg P, Schwindling FS. Nonsurgical treatment of class III malocclusion with temporomandibular disorder comorbidity: A clinical report. J Prosthet Dent 2021:S0022-3913(21)00512-6. [PMID: 34711408 DOI: 10.1016/j.prosdent.2021.09.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/20/2021] [Accepted: 09/21/2021] [Indexed: 11/25/2022]
Abstract
The treatment of a 57-year-old woman with combined skeletal and pseudo-class III malocclusion who was also suffering from chronic myofascial orofacial pain is described. The challenge was to treat the patient's malocclusion while simultaneously managing the temporomandibular disorder. After a successful 3-month occlusal device therapy, which substantially reduced the patient's discomfort, a nonsurgical therapy by using complete-mouth fixed restorations was planned. The treatment was first tested by using printed interim restorations before monolithic zirconia restorations were provided. Stable occlusion and a pain-free outcome were observed at the 3-month follow-up.
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Affiliation(s)
- Christopher Herpel
- Researcher, Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany.
| | - Peter Rammelsberg
- Professor of Dental Medicine, Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
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16
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Herpel C, Springer A, Puschkin G, Zimmermann L, Stober T, Rammelsberg P, Schwindling FS. Removable partial dentures retained by hybrid CAD/CAM cobalt-chrome double crowns: 1-year results from a prospective clinical study: CAD/CAM cobalt-chrome double crowns: 1-year results. J Dent 2021; 115:103847. [PMID: 34678336 DOI: 10.1016/j.jdent.2021.103847] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 10/06/2021] [Accepted: 10/10/2021] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES Computer-aided design and manufacturing (CAD/CAM) has been successfully used to replace conventional steps in the fabrication of double crowns, creating hybrid-workflows that might facilitate the wider application of these restorations in the future. However, in-vivo data are still lacking. METHODS A prospective clinical trial was designed in which 20 patients (median age = 69 years; n women = 10) with 73 abutment teeth who needed a double-crown-retained removable partial denture (RPD) were consecutively recruited. While most of the work steps were done conventionally, gypsum models were digitized with a laboratory scanner to allow CAD/CAM fabrication of primary crowns and secondary structures. DentalDesigner software (3Shape) was used in combination with milling unit PrograMillPM7 and Co-Cr- blanks (Ivoclar-vivadent). Connectors were milled from wax, transferred to Co-Cr using lost-wax technique and bonded to the secondary crowns. Clinical follow-ups were scheduled 6 and 12 months after prosthesis insertion. Outcome parameters were complication-free survival of RPDs and abutment teeth after one year. RESULTS After 12 months, complication-free survival was 74% and 91% for the RPDs and abutment teeth, respectively. Complications comprised decementations (n = 5), abutment tooth fractures (n = 2), fracture of denture teeth (n = 1), and loss of abutment teeth (n = 1). These complications were easily manageable, resulting in 1-year survival of 100% for CAD/CAM RPDs. CONCLUSIONS First data on short-term complication rates of CAD/CAM double-crown-retained RPDs appear promising. To gather further evidence, prospective clinical trials over a longer follow-up time and with larger patient groups are required. CLINICAL SIGNIFICANCE Hybrid CAD/CAM double-crown retained RPDs showed a successful clinical application after one year of follow-up. Further research is needed to evaluate their performance in comparison to conventional manufacturing methods.
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Affiliation(s)
- Christopher Herpel
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany.
| | - Antonia Springer
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany
| | - Galmunkh Puschkin
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany
| | - Lukas Zimmermann
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany
| | - Thomas Stober
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany
| | - Peter Rammelsberg
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany
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17
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Schwindling FS, Juerchott A, Boehm S, Rues S, Kronsteiner D, Heiland S, Bendszus M, Rammelsberg P, Hilgenfeld T. Three-dimensional accuracy of partially guided implant surgery based on dental magnetic resonance imaging. Clin Oral Implants Res 2021; 32:1218-1227. [PMID: 34352147 DOI: 10.1111/clr.13819] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 06/08/2021] [Accepted: 07/07/2021] [Indexed: 12/14/2022]
Abstract
OBJECTIVES To measure in vivo 3D accuracy of backward-planned partially guided implant surgery (PGIS) based on dental magnetic resonance imaging (dMRI). MATERIAL AND METHODS Thirty-four patients underwent dMRI examinations. Tooth-supported templates were backward planned using standard dental software, 3D-printed, and placed intraorally during a cone beam computed tomography (CBCT) scan. Treatment plans were verified for surgical viability in CBCT, and implants were placed with guiding of the pilot drill. High-precision impressions were taken after healing. The 3D accuracy of 41 implants was evaluated by comparing the virtually planned and definitive implant positions with respect to implant entry point, apex, and axis. Deviations from the dMRI-based implant plans were compared with the maximum deviations calculated for a typical single implant. RESULTS Twenty-eight implants were placed as planned in dMRI. Evaluation of 3D accuracy revealed mean deviations (99% confidence intervals) of 1.7 ± 0.9mm (1.2-2.1mm) / 2.3 ± 1.1mm (1.8-2.9 mm) / 7.1 ± 4.8° (4.6-9.6°) for entry point / apex / axis. The maximum deviations calculated for the typical single implant surpassed the upper bounds of the 99% CIs for the apex and axis, but not for the entry point. In the 13 other implants, dMRI-based implant plans were optimized after CBCT. Here, deviations between the initial dMRI plan and definitive implant position were only in part higher than in the unaltered group (1.9 ± 1.7 mm [0.5-3.4 mm] / 2.5 ± 1.5 mm [1.2-3.8 mm] / 6.8 ± 3.8° [3.6-10.1°] for entry point / apex / axis). CONCLUSIONS The 3D accuracy of dMRI-based PGIS was lower than that previously reported for CBCT-based PGIS. Nonetheless, the values seem promising to facilitate backward planning without ionizing radiation.
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Affiliation(s)
| | - Alexander Juerchott
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Sophia Boehm
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - Stefan Rues
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - Dorothea Kronsteiner
- Institute of Medical Biometry and Informatics, Heidelberg University Hospital, Heidelberg, Germany
| | - Sabine Heiland
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Martin Bendszus
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - Tim Hilgenfeld
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
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Tasaka A, Schwindling FS, Rues S, Rammelsberg P, Yamashita S. Retentive force of telescopic crowns combining fiber-reinforced composite and zirconia. J Prosthodont Res 2021; 66:265-271. [PMID: 34349081 DOI: 10.2186/jpr.jpr_d_20_00163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE This study investigated changes in the retentive force of telescopic crowns fabricated by combining a zirconia primary crown and a fiber-reinforced composite (FRC) secondary crown. METHODS Primary zirconia crowns were produced with a nominal convergence angle of 0°. Forty-eight secondary crowns were milled from FRC and divided into three study groups (n=16/group) based on milling parameters and post-milling adjustment. The offset parameter used for the final milling step of the inner crown surface was adjusted for a tight initial fit in Group 1 (milling offset: +10 µm, i.e., 2 × 10 µm = 20 µm lower inner diameter compared with the CAD file of the crown) and for improved initial fit (milling offset: -10 µm, i.e., an enlargement of the inner crown diameter by 2 × 20 µm = 40 µm in relation to Group 1) in Groups 2 and 3. The inner surfaces of the secondary crowns were polished with diamond paste in Groups 1 and 2, and silicon points were used for Group 3. The retentive force was measured using a universal testing device. The secondary crown was placed on the primary crown, with the final fitting force set to a load of 100 N. This test was conducted before and after aging (10,000 insertion/removal cycles) under dry and wet conditions. A generalized linear model was used to estimate the differences in the retentive force to elucidate the effects of the milling parameters and polishing methods. RESULTS We realized an initial retentive force of approximately 10 N. In Groups 2 and 3, the difference was statistically significant between the dry and wet conditions before aging (P < 0.05). There was no significant difference between the dry and wet conditions after aging in any of the groups (P > 0.05). CONCLUSIONS An adequate initial retentive force can be achieved with telescopic crowns combining zirconia and FRC.
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Affiliation(s)
- Akinori Tasaka
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg.,Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo
| | | | - Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg
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Leisner LC, Tasaka A, Trebing CT, Hilgenfeld T, Kosinski MA, Kronsteiner D, Rammelsberg P, Schwindling FS. Measuring peri-implant bone lesions using low-dose cone-beam computed tomography. J Prosthodont Res 2021; 66:326-332. [PMID: 34305085 DOI: 10.2186/jpr.jpr_d_20_00110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE High-definition cone-beam computed tomography (HD-CBCT) offers superior image quality at the cost of higher radiation dose compared to low-dose CBCT (LD-CBCT). The aim of this study was to investigate whether peri-implant bone lesions can be accurately quantified using LD-CBCT, even when including the influence of surrounding tissues. METHODS Twelve titanium implants restored with all-ceramic crowns were placed in bovine bone, and peri-implant lesions were prepared. Radiographic imaging was performed using IR (intraoral radiography), HD-CBCT and LD-CBCT. To simulate the in-vivo situation, the samples were placed inside a dry human mandible, and a second LD-CBCT imaging was performed (LD-CBCT*). The datasets were presented to four observers in random order. Maximum lesion depth and width were measured in a standardized mesiodistal slice in IR, HD-CBCT, LD-CBCT, and LD-CBCT*. Mean lesion depth and width measurements for each sample in HD-CBCT served as reference. RESULTS Interrater agreement was slight for depth and excellent for width in HD-CBCT and both LD modes. For all observers, measurement deviations from HD-CBCT were below 0.3 mm in the LD protocols (LD-CBCT depth: 0.22 ± 0.17 mm, width: 0.22 ± 0.13 mm; LD-CBCT* depth: 0.24 ± 0.23 mm, width: 0.25 ± 0.21 mm) and at 0.4 mm in IR. CONCLUSIONS Absolute differences between LD-CBCT and HD-CBCT are small, although surrounding tissues decrease LD-CBCT image quality. Within the limitations of an in-vitro trial, LD-CBCT may become an adequate imaging modality for monitoring peri-implant lesions at a substantially decreased radiation dose.
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Affiliation(s)
| | - Akinori Tasaka
- Department of Removable Partial Prosthodontics, Tokyo Dental College, Tokyo
| | | | - Tim Hilgenfeld
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg
| | | | - Dorothea Kronsteiner
- Institute of Medical Biometry and Informatics, Heidelberg University Hospital, Heidelberg
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg
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Schwindling FS, Bechtel KN, Zenthöfer A, Handermann R, Rammelsberg P, Rues S. In-vitro fit of experimental full-arch restorations made from monolithic zirconia. J Prosthodont Res 2021; 66:258-264. [PMID: 34305088 DOI: 10.2186/jpr.jpr_d_20_00321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE Fabrication inaccuracies can compromise the fit of large-span monolithic zirconia restorations. Sintering distortion is a particular problem. This study aimed to assess the fit of full-arch restorations made from mono lithic zirconia for different abutment configurations. METHODS To quantify fit inaccuracies created during the fabrication of experimental large-span restorations, an in-vitro model with eight abutment teeth was equipped with strain gauges. Ten 14-unit restorations were made from monolithic zirconia and seated on the model in turn. For each of the ten restorations, measurements were taken for three different abutment configurations-polygonal, quadrangular, and unilaterally shortened. Strains exerted during seating were recorded in the anterior-posterior and buccal-palatal directions, and the resulting horizontal forces (rhF) were calculated along with the respective abutment deflection (ad). Data were analyzed using Kruskal-Wallis tests at a significance level of 0.05. RESULTS All restorations could be seated on the multi-abutment model. The restorations exhibited fabrication misfits, tending to be too wide. Mean rhF/ad were largest for the quadrangular configuration (16.8±2.9 N/0.065 mm) and smallest for the polygonal configuration (13.6±4.5 N/0.053 mm). The largest rhF/ad were measured on abutments of the unilaterally shortened configuration, with a maximum deflection of 0.126 mm. For two of three configurations, rhF/ad were significantly larger for the distal abutments than for the other abutments. CONCLUSIONS Even if milling and sintering procedures are optimum, misfit-induced horizontal forces cannot be avoided. Because of the natural tooth mobility, however, the fit of full-arch restorations made from monolithic zirconia might be clinically acceptable.
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Affiliation(s)
| | | | - Andreas Zenthöfer
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg
| | - Rebecca Handermann
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg
| | - Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg
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21
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Horsch L, Labis C, Trebing CT, Kronsteiner D, Hilgenfeld T, Rammelsberg P, Schwindling FS. Predictability and image quality of low-dose cone-beam computed tomography in computer-guided implantology: An experimental study. J Dent 2021; 112:103744. [PMID: 34252488 DOI: 10.1016/j.jdent.2021.103744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 06/29/2021] [Accepted: 07/03/2021] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES To investigate the predictability and image quality of low-dose cone-beam computed tomography (LD-CBCT) in computer-guided implantology. METHODS Pig cadaver mandibles were imaged using high-definition CBCT (HD-CBCT) and LD-CBCT (HD-CBCT: 85 kV, 6 mA, 14.2 s, 767 frames, 1184 mGycm2, voxel size 80 µm, effective dose 231 µSv; LD-CBCT: 85 kV, 10 mA, 2.1 s, 384 frames, 84 mGycm2, voxel size 160 µm, effective dose 16 µSv; Orthophos SL, Dentsply Sirona, Bensheim, Germany). Digital impressions were taken using intraoral scanning (IOS; Omnicam, Dentsply Sirona). Data of CBCT modalities and IOS were aligned. Forty-eight implants were planned virtually (24 implants per modality; Bone Level 4.1 × 10 mm; Straumann AG, Basel, Switzerland). Implants were inserted using templates by initial pilot drilling ("partially-guided implantation"). Implant positions were recorded using IOS. Geometric deviations between planned and definitive positions were assessed regarding implant apex, entry-point and angle. CBCT image quality was evaluated by raters twice on a four point scale. The results were exploratively compared (linear models, Mann-Whitney-U tests). RESULTS Regarding implant apex, deviations were greater for LD-CBCT (mean 3.0±1.2 mm), as compared to HD-CBCT (mean 2.3±1.1 mm). For entry-point, no distinct difference was detected with a mean deviation of 1.4±0.9 mm in LD-CBCT, and 1.7±0.6 mm in HD-CBCT. Regarding angle, deviations were greater for LD-CBCT (mean 13.2±6.3°), as compared to HD-CBCT (mean 9.2±5.3°). The image quality of HD-CBCT provided to be better (mean 2.7±0.6) than that of LD-CBCT (mean 2.5±0.6). CONCLUSIONS Within the partially-guided approach, the results underline the potential of LD-CBCT alternatively to HD-CBCT for computer-guided implantology. Advantages of HD-CBCT need to be balanced against the higher radiation dose.
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Affiliation(s)
- Laura Horsch
- Department of Prosthodontics, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany.
| | - Christos Labis
- Department of Prosthodontics, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Charlotte Theresa Trebing
- Department of Prosthodontics, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Dorothea Kronsteiner
- Institute of Medical Biometry and Informatics, Heidelberg University Hospital, Im Neuenheimer Feld 130.3, 69120 Heidelberg, Germany
| | - Tim Hilgenfeld
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - Franz Sebastian Schwindling
- Department of Prosthodontics, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
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22
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Herpel C, Tasaka A, Higuchi S, Finke D, Kühle R, Odaka K, Rues S, Lux CJ, Yamashita S, Rammelsberg P, Schwindling FS. Accuracy of 3D printing compared with milling - A multi-center analysis of try-in dentures. J Dent 2021; 110:103681. [PMID: 33905767 DOI: 10.1016/j.jdent.2021.103681] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/15/2021] [Accepted: 04/17/2021] [Indexed: 02/01/2023] Open
Abstract
OBJECTIVES In recent years, computer-aided design/computer-aided manufacturing (CAD/CAM) has been used to produce removable complete dentures. Most workflows include fabrication of milled or 3D-printed try-in prostheses. 3D-printing accuracy is affected by laboratory-specific and operator-dependent factors. This international five-center study sought to compare the accuracy of 3D-printed and milled try-in dentures. METHODS The construction file of a maxillary removable complete denture was selected as a reference. Eight try-in dentures were 3D printed at each of the five centers. Each center used their own printer (Objet260 Connex, Stratasys; MAX, Asiga; Anycubic Photon, Anycubic 3D; PRO2, Asiga and cara Print 4.0, Kulzer) along with their own material, printing settings, post-processing and light-curing parameters. At center 2, eight try-in dentures were milled to serve as a benchmark (PrograMill PM7, Ivoclar Vivadent). Dentures were scanned and aligned to the reference file using best-fit algorithms. Geometric accuracy was analyzed using the root mean square value (trueness) and standard deviation (precision) of the distributed absolute mesh deviations. Mean values of the five sets of printed dentures and the single set of milled dentures were compared. RESULTS Milled dentures showed a mean trueness of 65 ± 6 μm and a mean precision of 48 ± 5 μm. Thus, they were significantly more accurate than the 3D-printed dentures in four out of five centers. In mean absolute numbers, 3D printing was less true than milling by 17-89 μm and less precise by 8-66 μm. CONCLUSIONS Although milling remains the benchmark technique for accuracy, differences between milled and 3D-printed dentures were non-significant for one printing center. Furthermore, the overall performance of 3D printing at all centers was within a clinically acceptable range for try-in prostheses. CLINICAL SIGNIFICANCE The accuracy of 3D printing varies widely between and within laboratories but nonetheless lies within the range of accuracy of conventional manufacturing methods.
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Affiliation(s)
- Christopher Herpel
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany.
| | - Akinori Tasaka
- Tokyo Dental College, Department of Removable Partial Prosthodontics, Tokyo, Japan; Tokyo Dental College, Oral Health Science Center, Tokyo, Japan
| | - Shizuo Higuchi
- Osaka Dental University, Faculty of Health Sciences, Department of Oral Engineering, Osaka, Japan
| | - Dominic Finke
- Heidelberg University Hospital, Department of Orthodontics, Heidelberg, Germany
| | - Reinald Kühle
- Heidelberg University Hospital, Department of Oral and Maxillofacial Surgery, Heidelberg, Germany
| | - Kento Odaka
- Tokyo Dental College, Department of Oral and Maxillofacial Radiology, Tokyo, Japan
| | - Stefan Rues
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany
| | - Christopher J Lux
- Heidelberg University Hospital, Department of Orthodontics, Heidelberg, Germany
| | - Shuichiro Yamashita
- Tokyo Dental College, Department of Removable Partial Prosthodontics, Tokyo, Japan
| | - Peter Rammelsberg
- Heidelberg University Hospital, Department of Prosthodontics, Heidelberg, Germany
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Herpel C, Kostunov J, Held T, Christ L, Adeberg S, Rammelsberg P, Schwindling FS. Tissue Retraction for Head and Neck Radiotherapy in Edentulous Patients. INT J PROSTHODONT 2021; 34:261-266. [PMID: 33882571 DOI: 10.11607/ijp.7241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Tissue retraction devices (TRDs) are used for head and neck radiotherapy to displace soft tissues and fixate the mandible. They can increase the accuracy of irradiation and reduce its side effects, such as oral mucositis. However, no method has been described for fabrication of TRDs in edentulous patients. In this case report, an edentulous 67-year-old patient undergoing radiotherapy of the tongue was provided with a TRD. The tongue was immobilized, ensuring irradiation consistency and the retraction of healthy oral tissues. Using 3D printing, an efficient workflow for fabrication of TRDs based on the patient's existing complete prostheses can be realized.
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Held T, Herpel C, Schwindling FS, Christ L, Lang K, Regnery S, Eichkorn T, Hommertgen A, Jaekel C, Krisam J, Moratin J, Mrosek J, Metzger K, Zaoui K, Moutsis T, Harrabi S, Herfarth K, Freudlsperger C, Rammelsberg P, Debus J, Adeberg S. 3D-printed individualized tooth-borne tissue retraction devices compared to conventional dental splints for head and neck cancer radiotherapy: a randomized controlled trial. Radiat Oncol 2021; 16:75. [PMID: 33865401 PMCID: PMC8052727 DOI: 10.1186/s13014-021-01803-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 04/07/2021] [Indexed: 02/19/2023] Open
Abstract
BACKGROUND Despite modern treatment techniques, radiotherapy (RT) in patients with head and neck cancer (HNC) may be associated with high rates of acute and late treatment-related toxicity. The most effective approach to reduce sequelae after RT is to avoid as best as possible healthy tissues and organs at risk from the radiation target volume. Even small geometric changes can lead to a significant dose reduction in normal tissue and better treatment tolerability. The major objective of the current study is to investigate 3D printed, tooth-borne tissue retraction devices (TRDs) compared to conventional dental splints for head and neck RT. METHODS In the current two-arm randomized controlled phase II trial, a maximum of 34 patients with HNC will be enrolled. Patients will receive either TRDs or conventional dental splints (randomization ratio 1:1) for the RT. The definition of the target volume, modality, total dose, fractionation, and imaging guidance is not study-specific. The primary endpoint of the study is the rate of acute radiation-induced oral mucositis after RT. The quality of life, local control and overall survival 12 months after RT are the secondary endpoints. Also, patient-reported outcomes and dental status, as well as RT plan comparisons and robustness analyzes, will be assessed as exploratory endpoints. Finally, mesenchymal stem cells, derived from the patients' gingiva, will be tested in vitro for regenerative and radioprotective properties. DISCUSSION The preliminary clinical application of TRD showed a high potential for reducing acute and late toxicity of RT in patients with HNC. The current randomized study is the first to prospectively investigate the clinical tolerability and efficacy of TRDs for radiation treatment of head and neck tumors. TRIAL REGISTRATION ClinicalTrials.gov; NCT04454697; July 1st 2020; https://clinicaltrials.gov/ct2/show/record/NCT04454697 .
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Affiliation(s)
- Thomas Held
- Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany.
- National Center for Tumor Diseases (NCT), Heidelberg, Germany.
| | - Christopher Herpel
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Leo Christ
- Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
| | - Kristin Lang
- Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
| | - Sebastian Regnery
- Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
| | - Tanja Eichkorn
- Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
| | - Adriane Hommertgen
- Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
| | - Cornelia Jaekel
- Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
| | - Johannes Krisam
- Institute of Medical Biometry and Informatics (IMBI), Heidelberg University Hospital, Heidelberg, Germany
| | - Julius Moratin
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Jan Mrosek
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Karl Metzger
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Karim Zaoui
- Department of Otorhinolaryngology, University of Heidelberg, Heidelberg, Germany
| | - Tracy Moutsis
- Department of Otorhinolaryngology, University of Heidelberg, Heidelberg, Germany
| | - Semi Harrabi
- Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
- Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, Germany
- German Cancer Consortium (DKTK), partner site Heidelberg, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Klaus Herfarth
- Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
- Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, Germany
- German Cancer Consortium (DKTK), partner site Heidelberg, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Christian Freudlsperger
- Department of Oral and Maxillofacial Surgery, University Hospital Heidelberg, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
- Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, Germany
- German Cancer Consortium (DKTK), partner site Heidelberg, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Sebastian Adeberg
- Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Heidelberg, Germany
- Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, Germany
- German Cancer Consortium (DKTK), partner site Heidelberg, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Trebing CT, Sen S, Rues S, Herpel C, Schöllhorn M, Lux CJ, Rammelsberg P, Schwindling FS. Non-invasive three-dimensional thickness analysis of oral epithelium based on optical coherence tomography-development and diagnostic performance. Heliyon 2021; 7:e06645. [PMID: 33898808 PMCID: PMC8055558 DOI: 10.1016/j.heliyon.2021.e06645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Revised: 02/12/2021] [Accepted: 03/26/2021] [Indexed: 12/12/2022] Open
Abstract
Objectives Evaluating structural changes in oral epithelium can assist with the diagnosis of cancerous lesions. Two-dimensional (2D) non-invasive optical coherence tomography (OCT) is an established technique for this purpose. The objective of this study was to develop and test the diagnostic accuracy of a three-dimensional (3D) evaluation method. Methods The oral lip mucosa of 10 healthy volunteers was scanned using an 870-nm spectral-domain OCT device (SD-OCT) with enhanced depth imaging (EDI). Four raters semi-automatically segmented the epithelial layer twice. Thus, eighty 3D datasets were created and analyzed for epithelial thickness. To provide a reference standard for comparison, the raters took cross-sectional 2D measurements at representative sites. The correlation between the 2D and 3D measurements, as well as intra- and inter-rater reliability, were analyzed using intraclass correlation coefficients (ICC). Results Mean epithelial thickness was 280 ± 64μm (range 178–500 μm) and 268 ± 49μm (range 163–425 μm) for the 2D and 3D analysis, respectively. The inter-modality correlation of the thickness values was good (ICC: 0.76 [0.626–0.846]), indicating that 3D analysis of epithelial thickness provides valid results. Intra-rater and inter-rater reliability were good (3D analysis) and excellent (2D analysis), suggesting high reproducibility. Conclusions Diagnostic accuracy was high for the developed 3D analysis of oral epithelia using non-invasive, radiation-free OCT imaging. Clinical significance This new 3D technique could potentially be used to improve time-efficiency and quality in the diagnosis of epithelial lesions compared with the 2D reference standard.
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Affiliation(s)
| | - Sinan Sen
- Department of Orthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Christopher Herpel
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Maria Schöllhorn
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Christopher J Lux
- Department of Orthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
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Herpel C, Schwindling FS, Held T, Christ L, Lang K, Schwindling M, Moratin J, Zaoui K, Moutsis T, Plinkert P, Herfarth K, Freudlsperger C, Rammelsberg P, Debus J, Adeberg S. Individualized 3D-Printed Tissue Retraction Devices for Head and Neck Radiotherapy. Front Oncol 2021; 11:628743. [PMID: 33833988 PMCID: PMC8021903 DOI: 10.3389/fonc.2021.628743] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 01/11/2021] [Indexed: 11/25/2022] Open
Abstract
Background Radiotherapy for head and neck cancer may cause various oral sequelae, such as radiation-induced mucositis. To protect healthy tissue from irradiation, intraoral devices can be used. Current tissue retraction devices (TRDs) have to be either individually manufactured at considerable cost and time expenditure or they are limited in their variability. In this context, a 3D-printed, tooth-borne TRD might further facilitate clinical use. Methods A novel approach for the manufacturing of TRDs is described and its clinical application is analysed retrospectively. The devices were virtually designed for fabrication by 3D-printing technology, enabling—in only a single printing design—caudal or bi-lateral tongue displacement, as well as stabilization of a tongue-out position. For a total of 10 patients undergoing radiotherapy of head and neck tumors, the devices were individually adapted after pre-fabrication. Technical and clinical feasibility was assessed along with patient adherence. Tissue spacing was calculated by volumetric analysis of tongue retraction. In one exemplary case, radiotherapy treatment plans before and after tissue displacement were generated and compared. The reproducibility of maxillomandibular relation at device re-positioning was quantified by repeated intraoral optical scanning in a voluntary participant. Results 3D-printing was useful for the simplification of TRD manufacture, resulting in a total patient treatment time of less than 30 min. The devices were tolerated well by all tested patients over the entire radiation treatment period. No technical complications occurred with the devices. The TRDs caused an effective spacing of the healthy adjacent tissue, e.g., the tongue. Position changes of maxillomandibular relation were limited to a mean value of 98.1 µm ± 29.4 µm root mean square deviation between initial reference and follow-up positions. Conclusions The presented method allows a resource-efficient fabrication of individualized, tooth-bourne TRDs. A high reproducibility of maxillomandibular relation was found and the first clinical experiences underline the high potential of such devices for radiotherapy in the head and neck area.
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Affiliation(s)
- Christopher Herpel
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Thomas Held
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), University Hospital Heidelberg, Heidelberg, Germany.,National Center for Tumor Diseases (NCT), University Hospital Heidelberg, Heidelberg, Germany
| | - Leo Christ
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Kristin Lang
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), University Hospital Heidelberg, Heidelberg, Germany.,National Center for Tumor Diseases (NCT), University Hospital Heidelberg, Heidelberg, Germany
| | | | - Julius Moratin
- Department of Oral and Maxillofacial Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Karim Zaoui
- Department of Otorhinolaryngology, University of Heidelberg, Heidelberg, Germany
| | - Tracy Moutsis
- Department of Otorhinolaryngology, University of Heidelberg, Heidelberg, Germany
| | - Peter Plinkert
- Department of Otorhinolaryngology, University of Heidelberg, Heidelberg, Germany
| | - Klaus Herfarth
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), University Hospital Heidelberg, Heidelberg, Germany.,National Center for Tumor Diseases (NCT), University Hospital Heidelberg, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), University Hospital Heidelberg, Heidelberg, Germany
| | - Christian Freudlsperger
- Department of Oral and Maxillofacial Surgery, Heidelberg University Hospital, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - Jürgen Debus
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), University Hospital Heidelberg, Heidelberg, Germany.,National Center for Tumor Diseases (NCT), University Hospital Heidelberg, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), University Hospital Heidelberg, Heidelberg, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,German Cancer Consortium (DKTK), partner site Heidelberg, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Sebastian Adeberg
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany.,Heidelberg Institute of Radiation Oncology (HIRO), University Hospital Heidelberg, Heidelberg, Germany.,National Center for Tumor Diseases (NCT), University Hospital Heidelberg, Heidelberg, Germany.,Heidelberg Ion-Beam Therapy Center (HIT), University Hospital Heidelberg, Heidelberg, Germany.,Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany.,German Cancer Consortium (DKTK), partner site Heidelberg, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Kern M, Behrendt C, Fritzer E, Kohal RJ, Luthardt RG, Maltzahn NFV, Rädel M, Reissmann DR, Schwindling FS, Wolfart S, Passia N. 5-year randomized multicenter clinical trial on single dental implants placed in the midline of the edentulous mandible. Clin Oral Implants Res 2020; 32:212-221. [PMID: 33258136 DOI: 10.1111/clr.13692] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 11/11/2020] [Accepted: 11/11/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVES This multicenter randomized controlled clinical trial was conducted to investigate whether the loading protocol of single dental implants placed in the midline of edentulous mandibles will influence the implant survival or prosthetic maintenance. MATERIALS AND METHODS In total, 158 patients were randomly assigned either to the immediate loading group (n = 81) or to the delayed loading group (n = 77). All implants were loaded with an overdenture retained by a ball attachment. RESULTS After 5 years, 102 patients attended the follow-up investigation. Immediately loaded single implants in the midline of the edentulous mandible revealed a statistically significant lower survival rate than implants loaded conventionally over an observation period of 5 years. In the immediate loading group, 9 implants failed within the first three months of implant loading. No further implant loss was recorded for this group. Two implants failed in the delayed loading group, whereas one implant had to be removed during second-stage surgery and the second five years after implant loading. Non-inferiority of the survival rate of the midline implant of the immediate loading group, compared with the delayed loading group, could not be shown (p = .79, CI immediate loading: 74.9%; 100.0%, CI delayed loading: 73.0%; 100.0%). The observed difference in implant survival between the two treatment groups over time was statistically significant. CONCLUSIONS The results of the present study indicate that immediate loading of a single mandibular implant in the edentulous mandible should be considered only in exceptional cases.
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Affiliation(s)
- Matthias Kern
- Department of Prosthodontics, Propaedeutics and Dental Materials, Christian-Albrechts University at Kiel, Kiel, Germany
| | - Christoph Behrendt
- Department of Prosthodontics, Gerodontology and Biomaterials, Greifswald University Hospital, Greifswald, Germany
| | - Elfriede Fritzer
- Center for Clinical Studies, University Hospital Schleswig-Holstein, Kiel University, Kiel, Germany
| | - Ralf J Kohal
- Department of Prosthetic Dentistry, Center for Dental Medicine, Medical Center - University Hospital Freiburg, Freiburg, Germany
| | - Ralph G Luthardt
- Center of Dentistry, Department of Prosthetic Dentistry, Ulm University Hospital, Ulm, Germany
| | - Nadine Frfr V Maltzahn
- Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, Hannover, Germany
| | - Michael Rädel
- Faculty of Medicine Carl Gustav Carus, TU Desden, Dresden, Germany
| | - Daniel R Reissmann
- Department of Prosthetic Dentistry, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | | | - Stefan Wolfart
- Department of Prosthodontics and Biomaterials, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - Nicole Passia
- Department of Prosthodontics, Propaedeutics and Dental Materials, Christian-Albrechts University at Kiel, Kiel, Germany.,Universitätsklinikum Schleswig-Holstein - Campus Kiel
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28
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Kostunov J, Rammelsberg P, Klotz AL, Zenthöfer A, Schwindling FS. Minimization of Tooth Substance Removal in Normally Calcified Teeth Using Guided Endodontics: An In Vitro Pilot Study. J Endod 2020; 47:286-290. [PMID: 33245970 DOI: 10.1016/j.joen.2020.10.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 10/18/2020] [Accepted: 10/26/2020] [Indexed: 11/15/2022]
Abstract
INTRODUCTION This study evaluated the success rate of and tooth substance removal required for computer-guided preparation of endodontic access cavities. METHODS Thirty acrylic typodont teeth with root canals (10 each of tooth numbers 11, 14, and 17) were randomly allocated to a study or control group (15 teeth per group). In the study group, teeth were fixed in acrylic resin and subsequently digitized using a laboratory scanner. A cone-beam computed tomographic scan was then taken. Access cavity preparations were planned virtually, and a template was 3-dimensionally printed. In the control group, access cavities were prepared using the conventional access technique. Tooth substance removal was assessed by weighing teeth before and after preparation. Volume loss was analyzed statistically by use of the Wilcoxon-Mann-Whitney test at a significance level of P < .05. RESULTS Using guided endodontics, 93.3% of root canals were located successfully compared with 100% of root canals using the conventional technique. In the control group, the mean tooth substance removal was 16.1 ± 3.7 mm³ for incisors, 44.2 ± 8.9 mm³ for premolars, and 99.3 ± 3.1 mm³ for molars. In the study group, significantly less tooth substance was removed; substance loss was 10.3 ± 1.1 mm³ for incisors, 29.3 ± 4.2 mm³ for premolars, and 51.8 ± 5.3 mm³ for molars. CONCLUSIONS The use of guided endodontics in normally calcified teeth enables the preservation of a significant amount of tooth substance. However, this advantage must be carefully balanced against a greater radiation burden and risk of perforation, higher costs, and more difficult debridement and visualization of the pulp chamber and root canals.
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Affiliation(s)
- Jana Kostunov
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany.
| | - Peter Rammelsberg
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - Anna-Luisa Klotz
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
| | - Andreas Zenthöfer
- Department of Prosthetic Dentistry, Heidelberg University Hospital, Heidelberg, Germany
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29
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Juerchott A, Sohani M, Schwindling FS, Jende JME, Kurz FT, Rammelsberg P, Heiland S, Bendszus M, Hilgenfeld T. Comparison of non‐contrast‐enhanced dental magnetic resonance imaging and cone‐beam computed tomography in assessing the horizontal and vertical components of furcation defects in maxillary molars: An in vivo feasibility study. J Clin Periodontol 2020; 47:1485-1495. [DOI: 10.1111/jcpe.13374] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 08/18/2020] [Accepted: 09/22/2020] [Indexed: 12/17/2022]
Affiliation(s)
- Alexander Juerchott
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
| | | | | | - Johann M. E. Jende
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
| | - Felix T. Kurz
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
| | - Peter Rammelsberg
- Department of Prosthodontics Heidelberg University Hospital Heidelberg Germany
| | - Sabine Heiland
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
| | - Martin Bendszus
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
| | - Tim Hilgenfeld
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
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30
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Trebing CT, Schwindling FS, Leisner L, Trebing J, Lux CJ, Rammelsberg P, Sen S. Diagnostic accuracy of 870-nm spectral-domain OCT with enhanced depth imaging for the detection of caries beneath ceramics. J Dent 2020; 102:103458. [PMID: 32866552 DOI: 10.1016/j.jdent.2020.103458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 10/23/2022] Open
Abstract
OBJECTIVES To evaluate the diagnostic accuracy of optical coherence tomography (OCT) for the non-invasive detection of caries adjacent to ceramic materials. METHODS Disks made from five ceramic materials (hybrid ceramic, feldspathic ceramic, zirconia-reinforced lithium silicate, lithium disilicate, and high-translucent zirconia) were ground to the recommended material thickness for single crown restorations and laminated with a 100 μm thick layer of one of three adhesive cements. The disks were fixed to extracted human molars with or without carious lesions of one of three standardized sizes. A total of 240 stacks of cross-sectional scans obtained using an 870-nm SD-OCT with enhanced depth imaging (EDI) were presented to five raters. Diagnostic accuracy was determined by rating the teeth beneath the cemented material as carious or healthy. RESULTS Carious samples were distinguished from sound teeth with high diagnostic accuracy, even for early stage caries. Sensitivity (SE) and specificity (SP) pooled over all raters and all materials were 0.9 and 0.97, respectively. When analyzing the effect of the ceramic and cement materials on detection rates, high SE and SP values of >0.96 and >0.91, respectively, were recorded for lithium disilicate, zirconia-reinforced lithium silicate, and high-translucent zirconia irrespective of the cement type. For hybrid and feldspathic ceramics, the cement material was found to have a significant effect on caries detection. CONCLUSIONS Given its high diagnostic accuracy, 870-nm SD-OCT with EDI might be useful for the detection of caries beneath restorative materials. The effect of the prescribed ceramic and cement material on optical penetration depth is substantial.
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Affiliation(s)
| | | | - Laura Leisner
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Johannes Trebing
- Department of Internal Medicine III: Cardiology, Angiology and Pneumology, Heidelberg University Hospital, Heidelberg, Germany
| | - Christopher J Lux
- Department of Orthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Sinan Sen
- Department of Orthodontics, Heidelberg University Hospital, Heidelberg, Germany
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31
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Juerchott A, Sohani M, Schwindling FS, Jende JME, Kurz FT, Rammelsberg P, Heiland S, Bendszus M, Hilgenfeld T. In vivo accuracy of dental magnetic resonance imaging in assessing maxillary molar furcation involvement: A feasibility study in humans. J Clin Periodontol 2020; 47:809-815. [DOI: 10.1111/jcpe.13299] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 04/07/2020] [Accepted: 04/18/2020] [Indexed: 01/04/2023]
Affiliation(s)
- Alexander Juerchott
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
| | | | | | - Johann M. E. Jende
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
| | - Felix T. Kurz
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
| | - Peter Rammelsberg
- Department of Prosthodontics Heidelberg University Hospital Heidelberg Germany
| | - Sabine Heiland
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
| | - Martin Bendszus
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
| | - Tim Hilgenfeld
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
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32
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Klotz A, Ehret J, Zajac M, Schwindling FS, Hassel AJ, Rammelsberg P, Zenthöfer A. The effects of prosthetic status and dementia on the chewing efficiency of seniors in nursing homes. J Oral Rehabil 2019; 47:377-385. [DOI: 10.1111/joor.12912] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 09/29/2019] [Accepted: 11/14/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Anna‐Luisa Klotz
- Department of Prosthodontics Dental School University of Heidelberg Heidelberg Germany
| | - Judith Ehret
- Department of Prosthodontics Dental School University of Heidelberg Heidelberg Germany
| | - Melania Zajac
- Department of Prosthodontics Dental School University of Heidelberg Heidelberg Germany
| | | | | | - Peter Rammelsberg
- Department of Prosthodontics Dental School University of Heidelberg Heidelberg Germany
| | - Andreas Zenthöfer
- Department of Prosthodontics Dental School University of Heidelberg Heidelberg Germany
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33
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Schwindling FS, Hilgenfeld T, Weber D, Kosinski MA, Rammelsberg P, Tasaka A. In vitro diagnostic accuracy of low‐dose CBCT for evaluation of peri‐implant bone lesions. Clin Oral Implants Res 2019; 30:1200-1208. [DOI: 10.1111/clr.13533] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 08/25/2019] [Accepted: 09/04/2019] [Indexed: 12/18/2022]
Affiliation(s)
| | - Tim Hilgenfeld
- Department of Neuroradiology Heidelberg University Hospital Heidelberg Germany
| | - Dorothea Weber
- Institute of Medical Biometry and Informatics Heidelberg University Heidelberg Germany
| | | | - Peter Rammelsberg
- Department of Prosthetic Dentistry Heidelberg University Hospital Heidelberg Germany
| | - Akinori Tasaka
- Department of Removable Partial Prosthodontics Tokyo Dental College Tokyo Japan
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34
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Hilgenfeld T, Juerchott A, Deisenhofer UK, Weber D, Rues S, Rammelsberg P, Heiland S, Bendszus M, Schwindling FS. In vivo accuracy of tooth surface reconstruction based on CBCT and dental MRI-A clinical pilot study. Clin Oral Implants Res 2019; 30:920-927. [PMID: 31257638 DOI: 10.1111/clr.13498] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 06/11/2019] [Accepted: 06/18/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Guided implant surgery (GIS) requires alignment of virtual models to reconstructions of three-dimensional imaging. Accurate visualization of the tooth surfaces in the imaging datasets is mandatory. In this prospective clinical study, in vivo tooth surface accuracy was determined for GIS using cone-beam computed tomography (CBCT) and dental magnetic resonance imaging (dMRI). MATERIALS AND METHODS CBCT and 3-Tesla dMRI were performed in 22 consecutive patients (mean age: 54.4 ± 15.2 years; mean number of restorations per jaw: 6.7 ± 2.7). Altogether, 92 teeth were included (31 incisor, 29 canines, 20 premolars, and 12 molars). Surfaces were reconstructed semi-automatically and registered to a reference standard (3D scans of stone models made from full-arch polyether impressions). Reliability of both methods was assessed using intraclass correlation coefficients. Accuracy was evaluated using the two one-sided tests procedure with a predefined equivalence margin of ±0.2 mm root mean square (RMS). RESULTS Inter- and intrarater reliability of tooth surface reconstruction were comparable for CBCT and dMRI. Geometric deviations were 0.102 ± 0.042 mm RMS for CBCT and 0.261 ± 0.08 mm RMS for dMRI. For a predefined equivalence margin, CBCT and dMRI were statistically equivalent. CBCT, however, was significantly more accurate (p ≤ .0001). For both imaging techniques, accuracy did not differ substantially between different tooth types. CONCLUSION Cone-beam computed tomography is an accurate and reliable imaging technique for tooth surfaces in vivo, even in the presence of metal artifacts. In comparison, dMRI in vivo accuracy is lower. Still, it allows for tooth surface reconstruction in satisfactory detail and within acceptable acquisition times.
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Affiliation(s)
- Tim Hilgenfeld
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Alexander Juerchott
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Dorothea Weber
- Institute of Medical Biometry and Informatics (IMBI), Heidelberg University Hospital, Heidelberg, Germany
| | - Stefan Rues
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Sabine Heiland
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Martin Bendszus
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
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35
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Hilgenfeld T, Juerchott A, Deisenhofer UK, Krisam J, Rammelsberg P, Heiland S, Bendszus M, Schwindling FS. Accuracy of cone-beam computed tomography, dental magnetic resonance imaging, and intraoral radiography for detecting peri-implant bone defects at single zirconia implants-An in vitro study. Clin Oral Implants Res 2018; 29:922-930. [PMID: 30112833 DOI: 10.1111/clr.13348] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 07/09/2018] [Accepted: 07/09/2018] [Indexed: 12/26/2022]
Abstract
OBJECTIVES To evaluate the diagnostic value of cone-beam computed tomography (CBCT), intraoral radiography (IR), and dental magnetic resonance imaging (dMRI) for detecting and classifying peri-implant bone defects at zirconia implants. MATERIALS AND METHODS Forty-eight zirconia implants were inserted in bovine ribs, 24 of which had standardized defects (1-wall, 2-wall, 3-wall, 4-wall) in two sizes (1 and 3 mm). CBCT, IR, and dMRI were performed and analyzed twice by four readers unaware of the nature of the defects. Cohen's and Fleiss' kappa (κ), sensitivity, and specificity were calculated for the presence/absence of bone defects, defect size, and defect type. Cochran's Q-test with post hoc McNemar was used to test for statistical differences. RESULTS A high intra- and inter-reader reliability (κ range: 0.832-1) and sensitivity/specificity (IR: 0.97/0.96; CBCT: 0.99/1; dMRI: 1/0.99) for bone defect detection were observed for all three imaging methods. For defect type classification, intra- (κ range: 0.505-0.778) and inter-reader (κ: 0.411) reliability of IR were lower compared to CBCT (κ range intrareader: 0.667-0.889; κ inter-reader: 0.629) and dMRI (κ range intrareader: 0.61-0.832; κ inter-reader: 0.712). The sensitivity for correct defect type classification was not significantly different for CBCT (0.81) and dMRI (0.83; p = 1), but was significantly lower for IR (0.68; vs. CBCT p = 0.003; vs. dMRI p = 0.004). The sensitivity advantage of CBCT and dMRI for defect classification was smaller for 1-mm defects (CBCT/dMRI/IR: 0.68/0.72/0.63, no significant difference) than for 3-mm defects (CBCT/dMRI/IR: 0.95/0.94/0.74; CBCT vs. IR p = 0.0001; dMRI vs. IR p = 0.003). CONCLUSION Within the limitations of an in vitro study, IR can be recommended as the initial imaging method for evaluating peri-implant bone defects at zirconia implants. CBCT provides higher diagnostic accuracy of defect classification at the expense of higher cost and radiation dose. Dental MRI may be a promising imaging method for evaluating peri-implant bone defects at zirconia implants in the future.
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Affiliation(s)
- Tim Hilgenfeld
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Alexander Juerchott
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Johannes Krisam
- Institute for Medical Biometry and Informatics, Heidelberg University Hospital, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Sabine Heiland
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Martin Bendszus
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
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36
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Schwindling FS, Raedel M, Passia N, Freitag-Wolf S, Wolfart S, Att W, Mundt T, Reissmann D, Ismail F, von Königsmark V, Kern M. The single mandibular implant study – Short-term effects of the loading protocol on Oral Health-related Quality of Life. J Prosthodont Res 2018; 62:313-316. [DOI: 10.1016/j.jpor.2017.12.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 09/28/2017] [Accepted: 12/15/2017] [Indexed: 10/17/2022]
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37
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Hilgenfeld T, Prager M, Schwindling FS, Nittka M, Rammelsberg P, Bendszus M, Heiland S, Juerchott A. MSVAT-SPACE-STIR and SEMAC-STIR for Reduction of Metallic Artifacts in 3T Head and Neck MRI. AJNR Am J Neuroradiol 2018; 39:1322-1329. [PMID: 29794233 DOI: 10.3174/ajnr.a5678] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 03/30/2018] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE The incidence of metallic dental restorations and implants is increasing, and head and neck MR imaging is becoming challenging regarding artifacts. Our aim was to evaluate whether multiple-slab acquisition with view angle tilting gradient based on a sampling perfection with application-optimized contrasts by using different flip angle evolution (MSVAT-SPACE)-STIR and slice-encoding for metal artifact correction (SEMAC)-STIR are beneficial regarding artifact suppression compared with the SPACE-STIR and TSE-STIR in vitro and in vivo. MATERIALS AND METHODS At 3T, 3D artifacts of 2 dental implants, supporting different single crowns, were evaluated. Image quality was evaluated quantitatively (normalized signal-to-noise ratio) and qualitatively (2 reads by 2 blinded radiologists). Feasibility was tested in vivo in 5 volunteers and 5 patients, respectively. RESULTS Maximum achievable resolution and the normalized signal-to-noise ratio of MSVAT-SPACE-STIR were higher compared with SEMAC-STIR. Performance in terms of artifact correction was dependent on the material composition. For highly paramagnetic materials, SEMAC-STIR was superior to MSVAT-SPACE-STIR (27.8% smaller artifact volume) and TSE-STIR (93.2% less slice distortion). However, MSVAT-SPACE-STIR reduced the artifact size compared with SPACE-STIR by 71.5%. For low-paramagnetic materials, MSVAT-SPACE-STIR performed as well as SEMAC-STIR. Furthermore, MSVAT-SPACE-STIR decreased artifact volume by 69.5% compared with SPACE-STIR. The image quality of all sequences did not differ systematically. In vivo results were comparable with in vitro results. CONCLUSIONS Regarding susceptibility artifacts and acquisition time, MSVAT-SPACE-STIR might be advantageous over SPACE-STIR for high-resolution and isotropic head and neck imaging. Only for materials with high-susceptibility differences to soft tissue, the use of SEMAC-STIR might be beneficial. Within limited acquisition times, SEMAC-STIR cannot exploit its full advantage over TSE-STIR regarding artifact suppression.
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Affiliation(s)
- T Hilgenfeld
- From the Department of Neuroradiology, (T.H., M.P., M.B., S.H., A.J.)
| | - M Prager
- From the Department of Neuroradiology, (T.H., M.P., M.B., S.H., A.J.).,Section of Experimental Radiology (M.P., S.H.), University of Heidelberg, Heidelberg, Germany
| | - F S Schwindling
- Department of Prosthodontics (F.S.S., P.R.), Heidelberg University Hospital, Heidelberg, Germany
| | - M Nittka
- Siemens Healthcare (M.N.), Erlangen, Germany
| | - P Rammelsberg
- Department of Prosthodontics (F.S.S., P.R.), Heidelberg University Hospital, Heidelberg, Germany
| | - M Bendszus
- From the Department of Neuroradiology, (T.H., M.P., M.B., S.H., A.J.)
| | - S Heiland
- From the Department of Neuroradiology, (T.H., M.P., M.B., S.H., A.J.).,Section of Experimental Radiology (M.P., S.H.), University of Heidelberg, Heidelberg, Germany
| | - A Juerchott
- From the Department of Neuroradiology, (T.H., M.P., M.B., S.H., A.J.)
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38
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Hilgenfeld T, Kästel T, Heil A, Rammelsberg P, Heiland S, Bendszus M, Schwindling FS. High-resolution dental magnetic resonance imaging for planning palatal graft surgery-a clinical pilot study. J Clin Periodontol 2018; 45:462-470. [PMID: 29334405 DOI: 10.1111/jcpe.12870] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/05/2018] [Indexed: 11/28/2022]
Abstract
AIM To evaluate whether high-resolution, non-contrast-enhanced dental magnetic resonance imaging (MRI) can be used for accurate determination of palatal masticatory mucosa thickness (PMMT) and to locate the greater palatal artery (GPA). MATERIALS AND METHODS In five volunteers (four males, one female; mean age 30.2 ± 0.4 years), two independent raters measured PMMT by use of dental MRI in 180 positions. For comparison, clinical bone sounding was performed. The GPA was identified in time-of-flight (TOF) angiography and MSVAT-SPACE-prototype sequence. Intra- and inter-observer agreement for MRI measurements, agreement between MRI and bone sounding were analysed by intra-class correlation coefficient (ICC) and Cohen's kappa (κ). RESULTS Reliability of dental MRI measurements was high (intra-observer-ICC 0.962; inter-observer ICC 0.959). Agreement of MRI measurements with bone sounding was moderate (ICC 0.744), and the GPA could be identified in 60% of measurement points using the TOF-angiography alone and in 85% with additional information of the MSVAT-SPACE. Good intra-observer agreement was observed for GPA identification (κ: 0.778). CONCLUSION Palatal masticatory mucosa thickness measured by high-resolution, non-contrast enhanced dental MRI is comparable with that obtained by bone sounding. Dental MRI enables reliable, non-invasive and radiation-free planning of palatal tissue harvesting and can also be used for location of the GPA at 85% of measurement points, which might help reduce complications during surgery.
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Affiliation(s)
- Tim Hilgenfeld
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Thorsten Kästel
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Alexander Heil
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Peter Rammelsberg
- Department of Prosthodontics, Heidelberg University Hospital, Heidelberg, Germany
| | - Sabine Heiland
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Martin Bendszus
- Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
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Heil A, Schwindling FS, Jelinek C, Fischer M, Prager M, Lazo Gonzalez E, Bendszus M, Heiland S, Hilgenfeld T. Determination of the palatal masticatory mucosa thickness by dental MRI: a prospective study analysing age and gender effects. Dentomaxillofac Radiol 2017; 47:20170282. [PMID: 28959890 DOI: 10.1259/dmfr.20170282] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
OBJECTIVES The aim of this prospective study was to evaluate age and gender effects on the palatal masticatory mucosa thickness by using non-invasive and non-ionizing MRI. METHODS 40 periodontally healthy participants of five gender-balanced age groups (20-29, 30-39, 40-49, 50-59 and 60-69 years, respectively) underwent dental MRI at 3 Tesla using a contrast-enhanced, high-resolution 3D-sequence. The palatal masticatory mucosa was measured at 40 standard measurement points by two independent observers. Statistical analysis was performed by using intraclass correlation coefficient (ICC), Shapiro-Wilk test, two-way analysis of variance and post-hoc Tukey HSD test. RESULTS Measurements of the palatal masticatory mucosa thickness were highly reliable with a mean intraobserver ICC of 0.989 and a mean interobserver ICC of 0.987. Mean palatal masticatory mucosa thickness increased with the distance from the gingival margin in all tooth regions. Molars showed a considerably lower average palatal masticatory mucosa thickness at intermediate heights in comparison to canines and premolars. Average palatal masticatory mucosa thickness continuously increased with age and significantly differed between age groups (p < 0.01). A significant increase was observed between the age groups of 30-39 years and 40-49 years (p = 0.04). Gender had no significant effect on average palatal mucosa thickness (p = 0.19). However, there was a tendency towards thicker mucosa in males (mean ± SD, 3.36 mm ± 0.47) compared to females (3.23 mm ± 0.44). CONCLUSIONS In the present study, dental MRI allowed for a highly reliable determination of the palatal masticatory mucosa thickness. Considerable intra- and interindividual variations in palatal masticatory mucosa thickness were observed. Average palatal masticatory mucosa thickness was dependent on age but not on gender.
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Affiliation(s)
- Alexander Heil
- 1 Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Constanze Jelinek
- 3 Department of Oral, Dental and Maxillofacial Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Manuel Fischer
- 4 Section of Experimental Radiology, Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Marcel Prager
- 4 Section of Experimental Radiology, Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Martin Bendszus
- 1 Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Sabine Heiland
- 4 Section of Experimental Radiology, Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
| | - Tim Hilgenfeld
- 1 Department of Neuroradiology, Heidelberg University Hospital, Heidelberg, Germany
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Schwindling FS, Krisam J, Hassel AJ, Rammelsberg P, Zenthöfer A. Long-term success of oral health intervention among care-dependent institutionalized seniors: Findings from a controlled clinical trial. Community Dent Oral Epidemiol 2017; 46:109-117. [DOI: 10.1111/cdoe.12335] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 08/10/2017] [Indexed: 11/27/2022]
Affiliation(s)
| | - Johannes Krisam
- Institute of Medical Biometry and Informatics; University Hospital Heidelberg; Heidelberg Germany
| | - Alexander J. Hassel
- Department of Prosthodontics; University Hospital Heidelberg; Heidelberg Germany
| | - Peter Rammelsberg
- Department of Prosthodontics; University Hospital Heidelberg; Heidelberg Germany
| | - Andreas Zenthöfer
- Department of Prosthodontics; University Hospital Heidelberg; Heidelberg Germany
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Hilgenfeld T, Prager M, Heil A, Schwindling FS, Nittka M, Grodzki D, Rammelsberg P, Bendszus M, Heiland S. PETRA, MSVAT-SPACE and SEMAC sequences for metal artefact reduction in dental MR imaging. Eur Radiol 2017; 27:5104-5112. [DOI: 10.1007/s00330-017-4901-1] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 03/14/2017] [Accepted: 05/16/2017] [Indexed: 01/13/2023]
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Schwindling FS, Rues S, Schmitter M. Fracture resistance of glazed, full-contour ZLS incisor crowns. J Prosthodont Res 2017; 61:344-349. [DOI: 10.1016/j.jpor.2016.12.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 11/14/2016] [Accepted: 12/23/2016] [Indexed: 10/20/2022]
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Schwindling FS, Rammelsberg P, Krisam J, Rues S. Adjustment of retention of all-ceramic double-crown attachments. Int J Comput Dent 2017; 20:409-421. [PMID: 29292414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
OBJECTIVES Double-crown attachments, such as conical crowns (CCs), can retain removable partial prostheses. Digital manufacturing enables the use of innovative materials such as zirconia, and new workflows. The aim of this study was to investigate options for the adjustment of retention forces of all-zirconia CCs. MATERIALS AND METHODS Single zirconia primary crowns were produced with convergence angles (α) of 3 and 4 degrees, together with monolithic zirconia secondary crowns (n = 8 for α = 3 degrees; n = 8 for α = 4 degrees). Retention was measured by fitting the crowns with forces F = 12.5 to 100 N, and evaluating the magnitudes of the forces required for loosening (L). L/F ratios were recorded, and the coefficient of friction (µ0) was calculated. To limit the maximum force required for loosening, and to prevent high tensile stresses within the crowns, the width of the occlusal gap between the primary and secondary crowns was limited by the implementation of occlusal stops. RESULTS True convergence angles were more conical than expected, by approximately 0.3 degrees. For α = 3 degrees and α = 4 degrees, L/F ratios were 0.308 (SD 0.04) and 0.208 (SD 0.068), respectively. The overall coefficient of static friction was µ0 = 0.113. Maximum retention forces were successfully controlled; the average values were 12.1 N (SD 4.5 N) for zirconia occlusal stops, and 12.8 N (SD 3.3 N) for composite occlusal stops. CONCLUSION The clinically desired L/F ratio of 1/3 was achieved by selecting 3-degree burs for fabrication of all-zirconia CCs. It is possible to limit retention, thereby reducing tensile stress in the circumferential direction in secondary crowns.
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Schwindling FS, Stober T. A comparison of two digital techniques for the fabrication of complete removable dental prostheses: A pilot clinical study. J Prosthet Dent 2016; 116:756-763. [DOI: 10.1016/j.prosdent.2016.03.022] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/23/2016] [Accepted: 03/23/2016] [Indexed: 11/30/2022]
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Schwindling FS, Schwindling FP. Mini dental implants retaining mandibular overdentures: A dental practice-based retrospective analysis. J Prosthodont Res 2016; 60:193-8. [PMID: 26783089 DOI: 10.1016/j.jpor.2015.12.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 12/11/2015] [Accepted: 12/24/2015] [Indexed: 11/25/2022]
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Schwindling FS, Deisenhofer UK, Séché AC, Lehmann F, Rammelsberg P, Stober T. Randomized trial investigating zirconia electroplated telescopic retainers: quality of life outcomes. Clin Oral Investig 2016; 21:1157-1163. [DOI: 10.1007/s00784-016-1869-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 06/02/2016] [Indexed: 11/28/2022]
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Hilgenfeld T, Prager M, Schwindling FS, Heil A, Kuchenbecker S, Rammelsberg P, Bendszus M, Heiland S. Artefacts of implant-supported single crowns - Impact of material composition on artefact volume on dental MRI. Eur J Oral Implantol 2016; 9:301-308. [PMID: 27722227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
PURPOSE MRI allows radiation-free imaging of the head and neck area. However, implant-supported prostheses may severely impair image quality due to artefacts. Therefore, identification of preferable material compositions for implants and supported prostheses with little impact on MR image quality is mandatory. MATERIALS AND METHODS Overall, one zirconia and four titanium dental implants were provided with different single crown materials: porcelain-fused-to-metal precious alloy (GP-T), porcelain-fused-to-metal non-precious alloy (CCT-T), porcelain-fused-to-zirconia (ZC-T) and monolithic zirconia (Z-T, Z-Z). Three-dimensional artefact volume was determined on a 3 Tesla MRI, applying two standard sequence types (SPACE and TSE). Two-way ANOVA and pair-wise post-hoc Turkey test were performed for comparison of artefact size. RESULTS Fewest MR artefacts were observed with zirconia implant combined with monolithic zirconia crown. A titanium implant combined with a single crown framework out of the non-precious alloys was unfavourable in terms of artefact volume. Smaller and comparable artefact volumes were noted for titanium implants with the remaining three crown materials (GP-T, ZC-T and Z-T). CONCLUSIONS Material composition of dental implants provided with single crowns has a profound impact on artefact volume. In comparison with crowns containing cobalt, chromium and tungsten, the MRI artefacts are reduced in precious alloy- and zirconia-based crowns. Further studies are needed to assess whether residual artefacts allow sufficient diagnostic imaging with these crowns. Conflict-of-interest statement: The authors have nothing to disclose.
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Schwindling FS, Deisenhofer UK, Porsche M, Rammelsberg P, Kappel S, Stober T. Establishing CAD/CAM in Preclinical Dental Education: Evaluation of a Hands-On Module. J Dent Educ 2015. [DOI: 10.1002/j.0022-0337.2015.79.10.tb06015.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | | | - Monika Porsche
- Central Evaluation Department; University Hospital Heidelberg; Germany
| | - Peter Rammelsberg
- Department of Prosthodontics; University Hospital Heidelberg; Germany
| | - Stefanie Kappel
- Department of Prosthodontics; University Hospital Heidelberg; Germany
| | - Thomas Stober
- Department of Prosthodontics; University Hospital Heidelberg; Germany
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Schwindling FS, Deisenhofer UK, Porsche M, Rammelsberg P, Kappel S, Stober T. Establishing CAD/CAM in Preclinical Dental Education: Evaluation of a Hands-On Module. J Dent Educ 2015; 79:1215-1221. [PMID: 26427781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The aim of this study was to evaluate a hands-on computer-assisted design/computer-assisted manufacture (CAD/CAM) module in a preclinical dental course in restorative dentistry. A controlled trial was conducted by dividing a class of 56 third-year dental students in Germany into study and control groups; allocation to the two groups depended on student schedules. Prior information about CAD/CAM-based restorations was provided for all students by means of lectures, preparation exercises, and production of gypsum casts of prepared resin teeth. The study group (32 students) then participated in a hands-on CAD/CAM module in small groups, digitizing their casts and designing zirconia frameworks for single crowns. The digitization process was introduced to the control group (24 students) solely by means of a video-supported lecture. To assess the knowledge gained, a 20-question written examination was administered; 48 students took the exam. The results were analyzed with Student's t-tests at a significance level of 0.05. The results on the examination showed a significant difference between the two groups: the mean scores were 16.8 (SD 1.7, range 13-19) for the study group and 12.5 (SD 3, range 4-18) for the control group. After the control group had also experienced the hands-on module, a total of 48 students from both groups completed a questionnaire with 13 rating-scale and three open-ended questions evaluating the module. Those results showed that the module was highly regarded by the students. This study supports the idea that small-group hands-on courses are helpful for instruction in digital restoration design. These students' knowledge gained and satisfaction seemed to justify the time, effort, and equipment needed.
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Affiliation(s)
- Franz Sebastian Schwindling
- Dr. Schwindling is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Deisenhofer is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Porsche is at the Central Evaluation Department, University Hospital Heidelberg, Germany; Dr. Rammelsberg is Professor and Chair, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Kappel is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; and Dr. Stober is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany.
| | - Ulrich Karl Deisenhofer
- Dr. Schwindling is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Deisenhofer is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Porsche is at the Central Evaluation Department, University Hospital Heidelberg, Germany; Dr. Rammelsberg is Professor and Chair, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Kappel is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; and Dr. Stober is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany
| | - Monika Porsche
- Dr. Schwindling is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Deisenhofer is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Porsche is at the Central Evaluation Department, University Hospital Heidelberg, Germany; Dr. Rammelsberg is Professor and Chair, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Kappel is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; and Dr. Stober is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany
| | - Peter Rammelsberg
- Dr. Schwindling is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Deisenhofer is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Porsche is at the Central Evaluation Department, University Hospital Heidelberg, Germany; Dr. Rammelsberg is Professor and Chair, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Kappel is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; and Dr. Stober is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany
| | - Stefanie Kappel
- Dr. Schwindling is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Deisenhofer is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Porsche is at the Central Evaluation Department, University Hospital Heidelberg, Germany; Dr. Rammelsberg is Professor and Chair, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Kappel is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; and Dr. Stober is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany
| | - Thomas Stober
- Dr. Schwindling is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Deisenhofer is Assistant Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Porsche is at the Central Evaluation Department, University Hospital Heidelberg, Germany; Dr. Rammelsberg is Professor and Chair, Department of Prosthodontics, University Hospital Heidelberg, Germany; Dr. Kappel is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany; and Dr. Stober is Associate Professor, Department of Prosthodontics, University Hospital Heidelberg, Germany
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Kohal RJ, Schwindling FS, Bächle M, Spies BC. Peri-implant bone response to retrieved human zirconia oral implants after a 4-year loading period: A histologic and histomorphometric evaluation of 22 cases. J Biomed Mater Res B Appl Biomater 2015; 104:1622-1631. [DOI: 10.1002/jbm.b.33512] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 06/30/2015] [Accepted: 08/14/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Ralf-Joachim Kohal
- Department of Prosthetic Dentistry; Center for Dental Medicine, Medical Center-University of Freiburg; Freiburg Germany
| | | | - Maria Bächle
- Department of Prosthetic Dentistry; Center for Dental Medicine, Medical Center-University of Freiburg; Freiburg Germany
| | - Benedikt Christopher Spies
- Department of Prosthetic Dentistry; Center for Dental Medicine, Medical Center-University of Freiburg; Freiburg Germany
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