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Sadid-Zadeh R, Lin K, Li R, Nagy K. Fracture strength of screw-retained zirconia crowns assembled on zirconia and titanium implants. J Prosthodont 2024; 33:273-280. [PMID: 36973859 DOI: 10.1111/jopr.13683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 03/04/2023] [Accepted: 03/20/2023] [Indexed: 03/29/2023] Open
Abstract
PURPOSE This in vitro study evaluated the fracture strength of screw-retained zirconia crowns connected to zirconia (Zr) and titanium (Ti) implants after undergoing a simulation of 5 years of clinical use. MATERIALS AND METHODS Forty-eight screw-retained zirconia crowns were fabricated and assembled on four implant systems, with 12 in each group: (1) Zr implant (pure ceramic; Straumann AG) (PZr); (2) Zr implant (NobelPearl; Nobel Biocare) (NPZr); (3) Ti-Zr implant (Bone Level Roxolid; Straumann AG) (RSTiZr); (4) Ti implant (Conical Connection PMC; Nobel Biocare) (NRTi). Crowns were luted to their associated abutments using resin cement and then torqued to their assigned implants at the recommended torque value. Specimens were subjected to dynamic loading for 1,200,000 loading cycles. Fracture strength, measured in Newtons (N), was tested under static compression load using a universal testing machine at an angle of 30°. One-way ANOVA and Tukey's multiple comparisons post hoc test were used to compare the mean fracture values between the groups at a significance level of 0.05. RESULTS The average fracture strengths for the RSTiZr and NRTi groups were 1207 ± 202 and 1073 ± 217 N, respectively, which was significantly (p < 0.0001) higher than the PZr and NPZr groups (712 ± 76 and 571.6 ± 167 N, respectively). However, no significant difference was found between the fracture strength value of RSTiZr and NRTi (p = 0.260) or PZr and NPZr (p = 0.256) groups. CONCLUSIONS Zirconia crowns connected to Zr implants have the potential to withstand the average physiological occlusal forces which occur in the anterior and premolar regions.
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Affiliation(s)
- Ramtin Sadid-Zadeh
- Department of Restorative Dentistry, University at Buffalo School of Dental Medicine, Buffalo, New York, USA
| | - Kevin Lin
- Department of Restorative Dentistry, University at Buffalo School of Dental Medicine, Buffalo, New York, USA
| | - Rui Li
- Department of Restorative Dentistry, University at Buffalo School of Dental Medicine, Buffalo, New York, USA
| | - Katalin Nagy
- Head of Oral Surgery, Faculty of Dentistry, University of Szeged, Szeged, Hungary
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Padhye NM, Calciolari E, Zuercher AN, Tagliaferri S, Donos N. Survival and success of zirconia compared with titanium implants: a systematic review and meta-analysis. Clin Oral Investig 2023; 27:6279-6290. [PMID: 37740825 PMCID: PMC10630218 DOI: 10.1007/s00784-023-05242-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 09/05/2023] [Indexed: 09/25/2023]
Abstract
OBJECTIVE This systematic review assessed the available evidence on the survival and success rate of zirconia and titanium implants. As secondary outcomes, aesthetic, radiographic and clinical parameters, as well as biological and mechanical complications, were considered. MATERIALS AND METHODS A systematic search was performed up to March 2022 to identify CCTs/RCTs comparing zirconia and titanium implants with a minimum of 12 months of follow-up. Meta-analysis was performed when ≥ 2 articles with similar characteristics were retrieved. RESULTS Four published articles with two RCTs (2 different patient populations) with 100 zirconia and 99 titanium implants that were followed up over 12-80 months were selected out of the 6040 articles. A non-statistically significant difference between zirconia and titanium implant survival at 12 months was suggested (P = 0.0938). The success rates were 57.5-93.3% and 57.1-100% for zirconia and titanium implants, respectively. The pink aesthetic score (PES) was higher for zirconia (10.33 ± 2.06 to 11.38 ± 0.92) compared to titanium implants (8.14 ± 3.58 to 11.56 ± 1.0). CONCLUSION Based on the 2 RCTs retrieved in the literature, similar survival rates were reported for zirconia and titanium implants in the short term (12 months of follow-up). Future RCTs are warranted to evaluate the long-term outcomes of zirconia implants. CLINICAL RELEVANCE Zirconia implants may be the procedure of choice, particularly in the aesthetic zone, since they show a similar survival and success rate as titanium implants on a short-term follow-up. TRIAL REGISTRATION Systematic review registration number-CRD42021288704 (PROSPERO).
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Affiliation(s)
- Ninad Milind Padhye
- Centre for Oral Clinical Research, Institute of Dentistry, Faculty of Medicine and Dentistry, Queen Mary University of London (QMUL), London, UK
| | - Elena Calciolari
- Centre for Oral Clinical Research, Institute of Dentistry, Faculty of Medicine and Dentistry, Queen Mary University of London (QMUL), London, UK
- Department of Medicine and Surgery, Centre of Dentistry, University of Parma, Parma, Italy
| | - Anina Nives Zuercher
- Centre for Oral Clinical Research, Institute of Dentistry, Faculty of Medicine and Dentistry, Queen Mary University of London (QMUL), London, UK
- Clinic of Reconstructive Dentistry, Centre of Dental Medicine, Zurich, Switzerland
| | - Sara Tagliaferri
- Department of Medicine and Surgery, University of Parma, Parma, Italy
- Center of Excellence for Toxicological Research, CERT, University of Parma, Parma, Italy
| | - Nikos Donos
- Centre for Oral Clinical Research, Institute of Dentistry, Faculty of Medicine and Dentistry, Queen Mary University of London (QMUL), London, UK.
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Helal E, Gierthmuehlen PC, Bonfante EA, Campos TMB, Prott LS, Langner R, Spitznagel FA. Influence of straight versus angulated screw channel titanium bases on failure loads of two-piece ceramic and titanium implants restored with screw-retained monolithic crowns: An in-vitro study. Clin Oral Implants Res 2023; 34:1217-1229. [PMID: 37565379 DOI: 10.1111/clr.14157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 07/13/2023] [Accepted: 07/25/2023] [Indexed: 08/12/2023]
Abstract
OBJECTIVE To analyze the influence of titanium-base (straight [SSC]/angulated-screw-channel [ASC]) on failure-loads and bending-moments of two-piece ceramic and titanium-zirconium implants restored with monolithic-zirconia crowns after fatigue. MATERIALS AND METHODS Thirty-two anterior monolithic-screw-retained zirconia crowns were divided into four groups (n = 8/group) according to the factors: (1) type of implant material: two-piece titanium-zirconium implant (Ti-Zr; control-group) versus two-piece ceramic implant (CI; test-group) and (2) type of titanium-base: SSC (0° angle) versus ASC (25°). An intact implant was used for field emission gun-scanning electronic microscopy (FEG-SEM) characterization and Raman spectroscopy for phase analyses and residual stress quantification. All samples were exposed to fatigue with thermodynamic loading (1.2-million-cycles, 49 N, 1.6 Hz, 5-55°C) at a 30° angle. Surviving specimens were loaded until failure (SLF) and bending moments were recorded. Failed samples were examined using light microscope and SEM. Statistical analyses included ANOVA and Mann-Whitney U-test. RESULTS Raman-spectroscopy revealed the presence of residual compressive stresses. FEG-SEM revealed a roughened surface between threads and polished surface at the cervical-collar of the ceramic implant. All samples survived fatigue and were free of complications. Mean bending-moments (±SD) were: Ti-Zr-0: 241 ± 45 N cm, Ti-Zr-25: 303 ± 86 N cm, CI-0: 326 ± 58 N cm, CI-25: 434 ± 71 N cm. Titanium-base and implant-material had significant effects in favor of ASC titanium bases (p = .001) and ceramic-implants (p < .001). Failure analysis after SLF revealed severe fractures in ceramic implants, whereas titanium implants were restricted to plastic deformation. CONCLUSIONS Ceramic and titanium implants exhibited high reliability after fatigue, with no failures. From a mechanical perspective, titanium bases with ASC can be recommended for both ceramic and titanium implants and are safe for clinical application.
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Affiliation(s)
- E Helal
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - P C Gierthmuehlen
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - E A Bonfante
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of Sao Paulo, Bauru, Brazil
| | - T M B Campos
- Department of Prosthodontics and Periodontology, Bauru School of Dentistry, University of Sao Paulo, Bauru, Brazil
| | - L S Prott
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
| | - R Langner
- Institute of Systems Neuroscience, Medical Faculty, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
- Institute of Neuroscience and Medicine, Brain and Behavior (INM-7), Research Center Jülich, Jülich, Germany
| | - F A Spitznagel
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Düsseldorf, Germany
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Choi SM, Choi H, Lee DH, Hong MH. Comparative finite element analysis of mandibular posterior single zirconia and titanium implants: a 3-dimensional finite element analysis. J Adv Prosthodont 2022; 13:396-407. [PMID: 35003555 PMCID: PMC8712109 DOI: 10.4047/jap.2021.13.6.396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 11/23/2021] [Accepted: 12/06/2021] [Indexed: 11/08/2022] Open
Abstract
PURPOSE Zirconia has exceptional biocompatibility and good mechanical properties in clinical situations. However, finite element analysis (FEA) studies on the biomechanical stability of two-piece zirconia implant systems are limited. Therefore, the aim of this study was to compare the biomechanical properties of the two-piece zirconia and titanium implants using FEA. MATERIALS AND METHODS Two groups of finite element (FE) models, the zirconia (Zircon) and titanium (Titan) models, were generated for the exam. Oblique (175 N) and vertical (175 N) loads were applied to the FE model generated for FEA simulation, and the stress levels and distributions were investigated. RESULTS In oblique loading, von Mises stress values were the highest in the abutment of the Zircon model. The von Mises stress values of the Titan model for the abutment screw and implant fixture were slightly higher than those of the Zircon model. Minimum principal stress in the cortical bone was higher in the Titan model than Zircon model under oblique and vertical loading. Under both vertical and oblique loads, stress concentrations in the implant components and bone occurred in the same area. Because the material itself has high stiffness and elastic modulus, the Zircon model exhibited a higher von Mises stress value in the abutments than the Titan model, but at a level lower than the fracture strength of the material. CONCLUSION Owing to the good esthetics and stress controllability of the Zircon model, it can be considered for clinical use.
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Affiliation(s)
- Sung-Min Choi
- Department of Dental Laboratory Science, College of Health Sciences, Catholic University of Pusan, Busan, Republic of Korea
| | - Hyunsuk Choi
- Department of Dentistry and Prosthodontics, Daegu Catholic University School of Medicine, Daegu, Republic of Korea
| | - Du-Hyeong Lee
- Department of Prosthodontics, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - Min-Ho Hong
- Department of Dental Laboratory Science, College of Health Sciences, Catholic University of Pusan, Busan, Republic of Korea
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Spitznagel FA, Balmer M, Wiedemeier DB, Jung RE, Gierthmuehlen PC. Clinical outcomes of all-ceramic single crowns and fixed dental prostheses supported by ceramic implants: A systematic review and meta-analyses. Clin Oral Implants Res 2021; 33:1-20. [PMID: 34665900 PMCID: PMC9297865 DOI: 10.1111/clr.13871] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 06/17/2021] [Accepted: 09/28/2021] [Indexed: 02/07/2023]
Abstract
Objective To analyze the clinical outcomes of all‐ceramic single crowns (SCs) and fixed dental prostheses (FDPs) supported by ceramic implants. Materials and Methods Based on a focused question and customized PICO framework, electronic (Medline/EMBASE/Cochrane) and manual searches for studies reporting the clinical outcomes of all‐ceramic SCs and FDPs supported by ceramic implants ≥12 months were performed. The primary outcomes were reconstruction survival and the chipping proportion. The secondary outcomes were implant survival, technical complications, and patient‐related outcome measurements. Meta‐analyses were performed after 1, 2, and 5 years using random‐effect meta‐analyses. Results Eight of the 1,403 initially screened titles and 55 full texts were included. Five reported on monolithic lithium disilicate (LS2) SCs, one on veneered zirconia SCs, and two on veneered zirconia SCs and FDPs, which reported all on cement‐retained reconstructions (mean observation: 12.0–61.0 months). Meta‐analyses estimated a 5‐year survival rate of 94% (95% confidence interval [CI]: 82%–100%) for overall implant survival. Reconstruction survival proportions after 5 years were: monolithic LS2, 100% (95%CI: 95%–100%); veneered zirconia SCs, 89% (95%CI: 62%–100%); and veneered zirconia FDPs 94% (95%CI: 81%–100%). The chipping proportion after 5 years was: monolithic LS2, 2% (95%CI: 0%–11%); veneered zirconia SCs, 38% (95%CI: 24%–54%); and veneered zirconia FDPs, 57% (95%CI: 38%–76%). Further outcomes were summarized descriptively. Conclusions Due to the limited data available, only tendencies could be identified. All‐ceramic reconstructions supported by ceramic implants demonstrated promising survival rates after mid‐term observation. However, high chipping proportions of veneered zirconia SCs and, particularly, FDPs diminished the overall outcome. Monolithic LS2 demonstrated fewer clinical complications. Monolithic reconstructions could be a valid treatment option for ceramic implants.
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Affiliation(s)
- Frank Akito Spitznagel
- Department of Prosthodontics, School of Dentistry, Heinrich-Heine-University, Düsseldorf, Germany
| | - Marc Balmer
- Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Daniel B Wiedemeier
- Statistical Services, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
| | - Ronald Ernst Jung
- Clinic of Reconstructive Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland
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Hanes B, Feitosa S, Phasuk K, Levon JA, Morton D, Lin WS. Fracture Resistance Behaviors of Titanium-Zirconium and Zirconia Implants. J Prosthodont 2021; 31:441-446. [PMID: 34632673 DOI: 10.1111/jopr.13440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/03/2021] [Indexed: 11/27/2022] Open
Abstract
PURPOSE To evaluate the fracture resistance behaviors of titanium-zirconium, one-piece zirconia, and two-piece zirconia implants restored by zirconia crowns and different combinations of abutment materials (zirconia and titanium) and retention modes (cement-retained and screw-retained zirconia crowns). MATERIAL AND METHODS Three research groups (n=12) were evaluated according to combinations of abutment material, retention mode, and implant type. In the control group (TTC), titanium-zirconium implants (∅ 4.1 mm RN, 12 mm, Roxolid; Straumann USA, Andover, MA) and prefabricated titanium abutments (RN synOcta Cementable Abutment, H 5.5 mm; Straumann USA) were used to support cement-retained zirconia crowns. In the second group (ZZC), one-piece zirconia implants (PURE Ceramic Implant Monotype, ∅ 4.1 mm RD, 12 mm, AH 5.5 mm; Straumann USA) were used to support cement-retained zirconia crowns. In the third group (ZTS), two-piece zirconia implants (PURE Ceramic Implant, ∅ 4.1 mm RD, 12 mm) and prefabricated titanium abutments (CI RD PUREbase Abutment, H 5.5 mm) were used to support screw-retained zirconia crowns. All zirconia crowns were manufactured in the same anatomic contour with a 5-axis dental mill and blended 3 and 5 mol% yttria-stabilized zirconia (LayZir A2). Implants were inserted into specimen holders made of epoxy resin-glass fiber composite. All specimens were then subject to artificial aging in an incubator at 37°C for 90 days. Fracture resistance of specimen assemblies was tested under static compression load using the universal testing machine based on ISO14801 specification. The peak fracture loads were recorded. All specimens were examined at the end of the test microscopically at 5× and 10× magnification to detect any catastrophic failures. Comparisons between groups for differences in peak fracture load were made using Wilcoxon Rank Sum tests and Weibull and Kaplan-Meier survival analyses (α = 0.05). RESULTS The TTC group (942 ± 241 N) showed significantly higher peak fracture loads than the ZZC (645 ± 165 N) and ZTS (650 ± 124 N) groups (p < 0.001), while there was no significant difference between ZZC and ZTS groups (p = 0.940). The survival probability based on the Weibull and Kaplan-Meier models demonstrated different failure molds between titanium-zirconium and zirconia implants, in which the TTC group remained in the plastic strain zone for a longer period before fracture when compared to ZZC and ZTS groups. Catastrophic failures, with implant fractures at the embedding level or slightly below, were only observed in the ZZC and ZTS groups. CONCLUSIONS Cement-retained zirconia crowns supported by titanium-zirconium implants and prefabricated titanium abutments showed superior peak fracture loads and better survival probability behavior. One-piece zirconia implants with cement-retained zirconia crowns and two-piece zirconia implants with screw-retained zirconia crowns on prefabricated titanium abutment showed similar peak fracture loads and survival probability behavior. Titanium-zirconium and zirconia implants could withstand average intraoral mastication loads in the incisor region. This study was conducted under static load, room temperature (21.7°C), and dry condition, and full impacts of intraoral hydrothermal aging and dynamic loading conditions on the zirconia implants should be considered and studied further.
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Affiliation(s)
- Brenda Hanes
- Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, IN
| | - Sabrina Feitosa
- Department of Biomedical Sciences and Comprehensive Care, Indiana University School of Dentistry, Indianapolis, IN
| | - Kamolphob Phasuk
- Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, IN
| | - John A Levon
- Department of Prosthodontic Dentistry, Indiana University School of Dentistry, Indianapolis, IN
| | - Dean Morton
- Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, IN
| | - Wei-Shao Lin
- Advanced Education Program in Prosthodontics, Department of Prosthodontics, Indiana University School of Dentistry, Indianapolis, IN
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Spitznagel FA, Röhrig S, Langner R, Gierthmuehlen PC. Failure Load and Fatigue Behavior of Monolithic Translucent Zirconia, PICN and Rapid-Layer Posterior Single Crowns on Zirconia Implants. MATERIALS 2021; 14:ma14081990. [PMID: 33921126 PMCID: PMC8071484 DOI: 10.3390/ma14081990] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 04/12/2021] [Accepted: 04/13/2021] [Indexed: 11/16/2022]
Abstract
This laboratory study aimed to evaluate the thermo-mechanical fatigue behavior and failure modes of monolithic and rapid-layer posterior single-crowns (SCs) supported by zirconia implants. Methods: 120 all-ceramic crowns supported by one-piece zirconia implants (ceramic.implant; vitaclinical) were divided into five groups (n = 24 each): Group Z-HT: 3Y-TZP monolithic-zirconia (Vita-YZ-HT); Group Z-ST: 4Y-TZP monolithic-zirconia (Vita-YZ-ST); Z-XT: 5Y-TZP monolithic-zirconia (Vita-YZ-XT); Group E: monolithic-polymer-infiltrated ceramic network (PICN,Vita-Enamic); Group RL (rapid layer): PICN-“table-top” (Vita-Enamic), 3Y-TZP-framework (Vita-YZ-HT). Half of the specimens of each group (n = 12) were exposed to fatigue with cyclic mechanical loading (F = 198N, 1.2-million cycles) and simultaneous thermocycling (5–55 °C). Single-load-to-failure testing (Z010, Zwick) was performed for all specimens without/with fatigue application. Data analysis was performed using ANOVA, Tukey’s post-hoc test, two-sample t-test and Bonferroni correction (p < 0.05). Results: All specimens survived fatigue exposure. Significant differences in failure loads were detected among groups (p ≤ 0.004). Materials Z-HT and Z-ST showed the highest failure loads followed by Z-XT, RL and E. The influence of fatigue was only significant for material RL. Conclusions: All types of tested materials exceeded clinically acceptable failure load values higher than 900N and can be recommended for clinical use. Z-HT and Z-ST appear to be highly reliable towards fatigue. Rapid-layer design of PICN and YZ-HT might be an interesting treatment concept for posterior implant SCs.
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Affiliation(s)
- Frank A. Spitznagel
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, 40225 Düsseldorf, Germany; (S.R.); (P.C.G.)
- Correspondence: ; Tel.: +49-211-81-04440
| | - Sara Röhrig
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, 40225 Düsseldorf, Germany; (S.R.); (P.C.G.)
| | - Robert Langner
- Institute of Systems Neuroscience, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany;
- Institute of Neuroscience and Medicine, Brain and Behaviour (INM-7), Research Centre Jülich, 52425 Jülich, Germany
| | - Petra C. Gierthmuehlen
- Department of Prosthodontics, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University, 40225 Düsseldorf, Germany; (S.R.); (P.C.G.)
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Tur D, Giannis K, Unger E, Mittlböck M, Rausch-Fan X, Strbac GD. Thermal effects of various drill materials during implant site preparation-Ceramic vs. stainless steel drills: A comparative in vitro study in a standardised bovine bone model. Clin Oral Implants Res 2020; 32:154-166. [PMID: 33220104 PMCID: PMC7898889 DOI: 10.1111/clr.13685] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/19/2020] [Accepted: 10/20/2020] [Indexed: 12/13/2022]
Abstract
OBJECTIVES The aim of this study was to evaluate thermal effects of ceramic and metal implant drills during implant site preparation using a standardised bovine model. MATERIAL AND METHODS A total of 320 automated intermittent osteotomies of 10- and 16-mm drilling depths were performed using zirconium dioxide-based and stainless steel drills. Various drill diameters (2.0/ 2.2, 2.8, 3.5, 4.2 mm ∅) and different cooling methods (without/ with external saline irrigation) were investigated at room temperature (21 ± 1°C). Temperature changes were recorded in real time using two custom-built multichannel thermoprobes in 1- and 2-mm distance to the osteotomy site. For comparisons, a linear mixed model was estimated. RESULTS Comparing thermal effects, significantly lower temperatures could be detected with steel-based drills in various drill diameters, regardless of drilling depth or irrigation method. Recorded temperatures for metal drills of all diameters and drilling depths using external irrigation were below the defined critical temperature threshold of 47°C, whereas ceramic drills of smaller diameters reached or exceeded the harmful temperature threshold at 16-mm drilling depths, regardless of whether irrigation was applied or not. The results of this study suggest that the highest temperature changes were not found at the deepest point of the osteotomy site but were observed at subcortical and deeper layers of bone, depending on drill material, drill diameter, drilling depth and irrigation method. CONCLUSIONS This standardised investigation revealed drill material and geometry to have a substantial impact on heat generation, as well as external irrigation, drilling depth and drill diameter.
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Affiliation(s)
- Dino Tur
- Clinical Division of Conservative Dentistry and Periodontology, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
| | - Katharina Giannis
- Clinical Division Unit-Dentistry Training, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
| | - Ewald Unger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, AKH Vienna, Vienna, Austria
| | - Martina Mittlböck
- Section for Clinical Biometrics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Xiaohui Rausch-Fan
- Clinical Division of Conservative Dentistry and Periodontology, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
| | - Georg D Strbac
- Clinical Division of Oral Surgery, University Clinic of Dentistry, Medical University of Vienna, Vienna, Austria
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