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Park GS, Chang J, Pyo SW, Kim S. Effect of scan body designs and internal conical angles on the 3-dimensional accuracy of implant digital scans. J Prosthet Dent 2024:S0022-3913(24)00284-1. [PMID: 38692945 DOI: 10.1016/j.prosdent.2024.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/03/2024] [Accepted: 04/04/2024] [Indexed: 05/03/2024]
Abstract
STATEMENT OF PROBLEM Axial displacement is inevitable when connecting scan bodies to implants for digital scans using intraoral scanners, and axial displacement may reduce implant position accuracy in digital casts. However, studies assessing scan body type and accuracy are lacking. PURPOSE The purpose of this in vitro study was to assess the linear and angular displacements of implants in digital casts using 2 scan body types with or without a vertical stop to minimize the axial displacement and 2 internal conical connection implants (ICCIs) with different internal conical angles. MATERIAL AND METHODS Two identical reference casts were fabricated from epoxy resin by duplicating a partially edentulous mandibular dentiform. Each cast received 3 implants in the left first premolar, first molar, and second molar regions. One cast received an ICCI with a 7-degree internal conical angle (7-degree ICCI), and the other received an ICCI with an 11-degree internal conical angle (11-degree ICCI). A 10-mm polyetheretherketone (PEEK) cube was attached to the buccal area of the mandibular second premolar of each reference cast. A vertical stop was used in the experimental scan bodies to minimize the axial displacement, and conventional scan bodies were hand tightened to the implants in the reference casts. An intraoral scanner was used to fabricate 4 digital cast groups (2 implant types and 2 scan body types; each group had 10 casts). A coordinate measuring machine and digital inspection software program were used to measure the implant platform centroids (x, y, z) and projection angles (θXY, θYZ, θZX) of implant long axes in the reference and digital casts, respectively. One-way analysis of variance (ANOVA) and linear mixed model both with Tukey post hoc and 2-way ANOVA tests were performed to assess the significance of linear and angular displacements between groups (α=.05). RESULTS Significant differences were noted in all linear displacement variables among the 4 digital cast groups, except for Δx in the left first premolar implant. For the 7-degree ICCI, the linear displacement was statistically similar in the experimental and conventional scan bodies. However, for the 11-degree ICCIs, the experimental scan body group resulted in significantly smaller Δy, Δz, and Δd (Δd2=Δx2+Δy2+Δz2) than the conventional scan body group (P<.05). Overall, the 11-degree ICCIs demonstrated a significantly greater linear displacement than the 7-degree ICCI, regardless of the scan body type (P<.05). Significant differences between the test groups were observed for 10 of the 12 angular displacement variables (P<.05). CONCLUSIONS The 11-degree ICCIs demonstrated significantly greater linear displacements in Δy, Δz, and Δr than the 7-degree ICCIs. The experimental scan bodies with a vertical stop demonstrated significantly smaller linear displacements in the 11-degree ICCIs.
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Affiliation(s)
- Gang Soo Park
- Resident, Department of Prosthodontics, Gangnam Severance Dental Hospital, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Jaeseung Chang
- Clinical Professor, Department of Prosthodontics, Gangnam Severance Dental Hospital, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Se-Wook Pyo
- Clinical Assistant Professor, Department of Prosthodontics, Gangnam Severance Dental Hospital, Yonsei University College of Dentistry, Seoul, Republic of Korea
| | - Sunjai Kim
- Professor and Chairman, Department of Prosthodontics, Gangnam Severance Dental Hospital, Yonsei University College of Dentistry, Seoul, Republic of Korea.
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Ashry A, Abdelhamid AM, Ezzelarab S, Khamis MM. Effect of using scan body accessories and inter-implant distances on the accuracy of complete arch implant digital impressions: An in vitro study. J Prosthodont 2024. [PMID: 38594949 DOI: 10.1111/jopr.13856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 03/23/2024] [Indexed: 04/11/2024] Open
Abstract
PURPOSE To introduce a novel design for scan body accessory parts that are reusable, easy to attach and detach without permanent change of the scan body, and can be used with different inter-implant distances to enhance the accuracy of complete arch implant scans. MATERIALS AND METHODS A maxillary polymethylmethacrylate (PMMA) model with a soft tissue replica was fabricated with four implant analogs located at tooth positions 17, 13, 22, and 27 with 18, 25, and 30 mm inter-implant distances. Four scan bodies (SBs) were attached to the implants. The model was scanned with a laboratory scanner to be used as a reference scan. A total of 40 scans were made with the same intraoral scanner and they were divided equally into two groups. Group A: Complete arch implant scans without scan body accessories (n = 20), and Group B: Complete arch implant scans with scan body accessories (n = 20). Intraoral scans were exported and superimposed on the reference scan using reverse engineering inspection software to be evaluated for 3D deviations, angular deviations, and linear deviations. Statistical analysis was performed with student t-test and analysis of variance (ANOVA) with repeated measures followed by post hoc adjusted Bonferroni test. The level of significance was set at P = 0.05. RESULTS The scan body accessories decreased both the 3D and linear deviations, with a statistically significant difference at SB4 for the 3D deviation (P = 0.043) and the linear inter-implant discrepancies between SB1-SB2 and SB3-SB4 (P = 0.029 and < 0.001), respectively. However, there was no statistically significant difference in angular deviation between the study groups. Implant positions had significant differences within each group. CONCLUSIONS A significant improvement in the accuracy of the complete arch implant digital impression was achieved by using the scan body accessories, particularly in reducing the 3D and linear deviations at the most distant implant positions.
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Affiliation(s)
- Amal Ashry
- Department of Prosthodontics, Faculty of Dentistry, Damanhour University, El-Behaira, Egypt
- Department of Prosthodontics, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Ahmed M Abdelhamid
- Department of Prosthodontics, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Salah Ezzelarab
- Department of Prosthodontics, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
| | - Mohamed Moataz Khamis
- Department of Prosthodontics, Faculty of Dentistry, Alexandria University, Alexandria, Egypt
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Kropfeld J, Berger L, Adler W, Schulz KL, Motel C, Wichmann M, Matta RE. Impact of Scanbody Geometry and CAD Software on Determining 3D Implant Position. Dent J (Basel) 2024; 12:94. [PMID: 38668006 PMCID: PMC11049057 DOI: 10.3390/dj12040094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 03/28/2024] [Accepted: 03/31/2024] [Indexed: 04/28/2024] Open
Abstract
The implementation of CAD software in the digital production of implant prosthetics stands as a pivotal aspect of clinical dentistry, necessitating high precision in the alignment of implant scanbodies. This study investigates the influence of scanbody geometry and the method of superimposing in CAD software when determining 3D implant position. A standardized titanium model with three bone-level implants was digitized to create reference STL files, and 10 intraoral scans were performed on Medentika and NT-Trading scanbodies. To determine implant position, the generated STL files were imported into the Exocad CAD software and superimposed-automatically and manually-with the scanbody geometries stored within the software's shape library. Position accuracy was determined by a comparison of the 3D-defined scanbody points from the STL matching files with those from the reference STL files. The R statistical software was used for the evaluation of the data. In addition, mixed linear models and a significance level of 0.05 were applied to calculate the p-values. The manual overlay method was significantly more accurate than the automatic overlays for both scanbody types. The Medentika scanbodies showed slightly superior precision compared to the NT-Trading scanbodies. Both scanbody geometry and the type of alignment in the CAD software significantly affect digital workflow accuracy. Manual verification and adjustment of the automatic alignment process are essential for precise implant positioning.
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Affiliation(s)
- Judith Kropfeld
- Department of Prosthodontics, University Hospital Erlangen, Glückstrasse 11, 91054 Erlangen, Germany; (J.K.); (L.B.); (C.M.); (M.W.)
| | - Lara Berger
- Department of Prosthodontics, University Hospital Erlangen, Glückstrasse 11, 91054 Erlangen, Germany; (J.K.); (L.B.); (C.M.); (M.W.)
| | - Werner Adler
- Institute of Medical Informatics, Biometry and Epidemiology (IMBE) of the Friedrich-Alexander-University, Erlangen-Nuremberg, Waldstrasse 6, 91054 Erlangen, Germany;
| | - Katja Leonie Schulz
- Department of Oral and Cranio-Maxillofacial Surgery, University Hospital Erlangen, Glückstrasse 11, 91054 Erlangen, Germany;
| | - Constantin Motel
- Department of Prosthodontics, University Hospital Erlangen, Glückstrasse 11, 91054 Erlangen, Germany; (J.K.); (L.B.); (C.M.); (M.W.)
| | - Manfred Wichmann
- Department of Prosthodontics, University Hospital Erlangen, Glückstrasse 11, 91054 Erlangen, Germany; (J.K.); (L.B.); (C.M.); (M.W.)
| | - Ragai Edward Matta
- Department of Prosthodontics, University Hospital Erlangen, Glückstrasse 11, 91054 Erlangen, Germany; (J.K.); (L.B.); (C.M.); (M.W.)
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Nuytens P, Grande F, D'haese R, Salameh Z, Lepidi L. Novel complete-arch pillar system (CAPS) to register implant position and maxillomandibular relationship in one single visit. J Dent 2024; 143:104885. [PMID: 38346663 DOI: 10.1016/j.jdent.2024.104885] [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: 11/11/2023] [Revised: 01/28/2024] [Accepted: 02/07/2024] [Indexed: 02/23/2024] Open
Abstract
OBJECTIVES This article presents a novel complete-arch pillar system (CAPS) to register implant position and maxillomandibular relationship in one single visit for implant-supported fixed complete dental prostheses (IFCDPs). MATERIAL AND METHODS The novel system presents a 3-unit toolset comprising intraoral scan bodies (ISBs), lateral pillar attachments (LPAs) and occlusal pillar attachments (OPAs). A 2-stage single visit workflow by an intraoral scanner (Trios 5) was introduced. The first stage "Screw-Scan-Done" was used to describe complete-arch intraoral implant scanning using LPAs. The second stage "Screw-Occlude-Done" involved virtual occlusal recording using OPAs. Two patients with one single edentulous arch were selected for this study. In the first patient, 6 bone level implants (Bone Level Tapered, Straumann) were placed in the edentulous maxilla at positions 12, 14, 16, 22, 24 and 26. In the second patient, 4 bone level implants (NobelActive CC, Nobel Biocare) were placed in the edentulous mandible at positions 32, 35, 42 and 45. A CAD-CAM procedure was initiated with the acquired IOS data to fabricate an interim IFCDP at the same day. Periapical radiographs were obtained of the implant-prosthetic connection of the definitive IFCDPs to verify the passive fit. Metrology software (Geomagic Qualify, 3D Systems - Matlab, Mathworks) was used to assess the implant analogs position in the 3D-printed casts used for fabricating the definitive IFCDPs. A quantitative occlusal relationship analysis was performed with IOS. RESULTS Radiographic examination revealed no gaps at implant-prosthetic connection of the definitive IFCDPs. The 3D-printed casts showed an overall average distance deviation within the clinically acceptable range of errors of 150 µm. Quantitative occlusal relationship analysis with IOS showed well-distributed contacts. CONCLUSION Within the limitations of this study, the following conclusions can be drawn: (1) A 3-unit toolset with ISBs, LPAs and OPAs allows to register the implant position and maxillomandibular relationship in one single visit; (2) the 2-stage clinical workflow with the CAPS system facilitates the IOS data acquisition for fabrication of an interim IFCDP at the same day; (3) a passive fit was demonstrated for the interim and the definitive IFCDPs. CLINICAL SIGNIFICANCE The CAPS system can help clinicians to register the implant position and the maxillomandibular relationship in one single visit for the fabrication of an IFCDP.
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Affiliation(s)
- Philippe Nuytens
- Department of Reconstructive Dentistry, Faculty of Medicine and Health Sciences, Ghent University, C. Heymanslaan 10, 9000 Ghent, Belgium.
| | - Francesco Grande
- Department of Prosthodontics, University of Ferrara, Ferrara, Italy; Department of Mechanical and Aerospace Engineering, Politecnico di Torino, Turin, Italy
| | - Rani D'haese
- Department of Reconstructive Dentistry, Faculty of Medicine and Health Sciences, Ghent University, C. Heymanslaan 10, 9000 Ghent, Belgium
| | - Ziad Salameh
- Professor and Director, Research Center, Faculty of Dental Medicine, Lebanese University Beirut, Lebanon
| | - Luca Lepidi
- Adjunct Professor, Department of Prosthodontics, University of Ferrara, Italy
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Revilla-León M, Gómez-Polo M, Drone M, Barmak AB, Guinot-Barona C, Att W, Kois JC, Alonso Pérez-Barquero J. Impact of scanning distance on the accuracy of a photogrammetry system. J Dent 2024; 142:104854. [PMID: 38246309 DOI: 10.1016/j.jdent.2024.104854] [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: 10/21/2023] [Revised: 12/26/2023] [Accepted: 01/18/2024] [Indexed: 01/23/2024] Open
Abstract
PURPOSE To measure the impact of the scanning distance on the accuracy of complete-arch implant scans acquired by using a photogrammetry (PG) system. MATERIAL AND METHODS An edentulous cast with 6 implant abutment analogs was obtained. A brand new implant scan body was positioned on each implant abutment and digitized using an extraoral scanner (T710; Medit) and the reference file was obtained. Three groups were created based on the scanning distance used to acquire complete-arch implant scans by using a PG (PIC System; PIC Dental): 20 (20 group), 30 (30 group), and 35 cm (35 group). An optical marker (PIC Transfer, HC MUA Metal; PIC Dental) was placed on each implant abutment and a total of thirty scans per group were acquired. Euclidean linear and angular measurements were obtained on the reference file was obtained and used to compare the discrepancies with the same measurements obtained on each experimental scan. One-way ANOVA and Tukey tests were used to analyze trueness. The Levene test was used to analyze the precision values (α = 0.05). RESULTS Significant linear (P < .001) and angular trueness (P < .001) discrepancies were found among the groups. For linear trueness, Tukey test showed that the 20 and 30 groups (P < .001) and 30 and 35 groups were different (P < .001). For angular trueness, the Tukey test revealed that 20 and 30 groups (P = .003), 20 and 35 (P < .001), and 30 and 35 groups were different (P < .001) The Levene test showed no significant linear precision (P = .197) and angular discrepancies (P = .229) among the groups. CONCLUSIONS The scanning distance influenced the trueness of complete-arch implant scans obtained with the PG method tested. The maximum linear trueness mean discrepancy among the groups tested was 10 µm and the maximum angular trueness mean discrepancy among the groups tested was 0.02 .
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Affiliation(s)
- Marta Revilla-León
- Graduate Prosthodontics, Department of Restorative Dentistry, School of Dentistry, Faculty & Director of Research and Digital Dentistry, Kois Center, University of Washington, Seattle, WA, United States; Graduate Prosthodontics, Department of Prosthodontics, School of Dental Medicine, Tufts University, Boston, MA, United States
| | - Miguel Gómez-Polo
- Department of Conservative Dentistry and Prosthodontics, School of Dentistry, Complutense University of Madrid, Pza. Ramón y Cajal s/n., Madrid 28033, Spain.
| | | | - Abdul B Barmak
- Clinical Research and Biostatistics, Eastman Institute of Oral Health, University of Rochester Medical Center, Rochester, NY, United States
| | - Clara Guinot-Barona
- Department of Dental Orthodontics, Faculty of Medicine and Health Sciences, Universidad Católica de Valencia, Valencia, Spain
| | - Wael Att
- Founder and Director, The Face Dental Group, Boston, MA, United States; Department of Prosthodontics, University Hospital of Freiburg, Germany
| | - John C Kois
- Founder and Director Kois Center, Affiliate Professor, Graduate Prosthodontics, Department of Restorative Dentistry, School of Dentistry, University of Washington, and Private Practice, Seattle, WA, United States
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Zhang T, Yang B, Ge R, Zhang C, Zhang H, Wang Y. Effect of a Novel 'Scan Body' on the In Vitro Scanning Accuracy of Full-Arch Implant Impressions. Int Dent J 2024:S0020-6539(24)00039-X. [PMID: 38368235 DOI: 10.1016/j.identj.2024.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 01/18/2024] [Accepted: 01/22/2024] [Indexed: 02/19/2024] Open
Abstract
OBJECTIVE This in vitro study aimed to determine whether a newly designed arcuate scan body can improve intraoral scanning accuracy for implant rehabilitation of edentulous jaws. MATERIAL AND METHODS A master model containing 4 implant abutment replicas was fabricated and digitized with different scan bodies using an intraoral scanner. Four types of scan bodies were evaluated: original scan bodies (group OS), computer-aided design and computer-aided manufacturing (CAD/CAM) scan bodies without extension (group CS), CAD/CAM scan bodies with straight extension (group CSS), and CAD/CAM scan bodies with arcuate extension (group CSA). Conventional splinted open-tray impressions (group CI) were used as controls. The master model and the poured casts were digitized using a laboratory scanner. Impressions were repeated 10 times each in 5 groups. Scans in standard tessellation language format were exported to reverse engineering software and root mean square (RMS) values were used for trueness and precision assessments. In each group, 45 RMS values were acquired for precision evaluation and 10 RMS values were obtained for trueness assessment. Statistical evaluation was performed with the Kruskal-Wallis test and Dunn-Bonferroni test (α = 0.05). RESULTS The median trueness values were 41.40, 55.95, 39.80, 39.75, and 22.30 μm for group OS, CS, CSS, CSA, and CI, respectively. CI showed better trueness than OS (P = .020), CS (P < .001), and CSS (P = .035). The median precisions for group OS, CS, CSS, CSA, and CI were 47.40, 51.50, 43.90, 25.20, and 24.60 μm. respectively. The precision of CSA and CI were higher than OS (P < .001), CS (P < .001), and CSS (P < .001). Between CI and CSA, there was no significant difference (P = 1.000). CONCLUSIONS For full-arch implant rehabilitation, the scan body with arcuate extension could improve the intraoral scanning precision and showed similar 3-dimensional discrepancy compared to conventional splinted open-tray impressions.
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Affiliation(s)
- Tingting Zhang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangdong Provincial Clinical Research Center of Oral Diseases, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China
| | - Bo Yang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangdong Provincial Clinical Research Center of Oral Diseases, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China
| | - Ruihan Ge
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangdong Provincial Clinical Research Center of Oral Diseases, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China
| | | | - Hui Zhang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangdong Provincial Clinical Research Center of Oral Diseases, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China.
| | - Yan Wang
- Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangdong Provincial Clinical Research Center of Oral Diseases, Guangdong Provincial Key Laboratory of Stomatology, Guangzhou, Guangdong, China.
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Revilla-León M, Gómez-Polo M, Drone M, Barmak AB, Att W, Kois JC, Alonso Pérez-Barquero J. Influence of implant reference on the scanning accuracy of complete arch implant scans captured by using a photogrammetry system. J Prosthet Dent 2024:S0022-3913(24)00007-6. [PMID: 38267350 DOI: 10.1016/j.prosdent.2024.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 01/02/2024] [Accepted: 01/05/2024] [Indexed: 01/26/2024]
Abstract
STATEMENT OF PROBLEM Photogrammetry has been reported to be a reliable digital alternative for recording implant positions; however, the factors that may impact the accuracy of photogrammetry techniques remain unknown. PURPOSE The purpose of this in vitro study was to assess the influence of the implant reference on the accuracy of complete arch implant scans acquired by using a photogrammetry system. MATERIAL AND METHODS An edentulous cast with 6 implant abutment analogs (MultiUnit Abutment Plus Replica) was obtained and digitized by using a laboratory scanner (T710; Medit). A photogrammetry system (PIC System) was selected to obtain complete arch implant scans. An optical marker (PIC Transfer, HC MUA Metal; PIC Dental) was positioned on each implant abutment of the reference cast. Each optical marker code and position was determined in the photogrammetry software program. Three groups were created based on the implant reference selected before acquiring the photogrammetry scans: right first molar (IPR-3 group), left canine (IPR-11 group), and left first molar (IPR-14 group) (n=30). Euclidean linear and angular measurements were obtained on the digitized reference cast and used to compare the discrepancies with the same measurements obtained on each experimental scan. One-way ANOVA and the Tukey tests were used to analyze the trueness data. The Levene test was used to analyze the precision values (α=.05 for all tests). RESULTS One-way ANOVA revealed significant linear (P=.003) and angular (P=.009) trueness differences among the groups tested. Additionally, the Tukey test showed that the IPR-11 and IPR-14 groups had significantly different linear (P<.001) and angular trueness (P<.001). The Levene test showed no significant precision linear (P=.197) and angular (P=.235) discrepancies among the groups tested. The IPR-3 group obtained the highest trueness (P<.001) and precision (P<.001) values among the groups tested. CONCLUSIONS Implant reference impacted the accuracy of complete arch implant scans obtained by using the photogrammetry system tested. However, a trueness ±precision linear discrepancy of 6 ±3 µm and an angular discrepancy of 0.01 ±0.01 degrees were measured among the groups tested; therefore, the impact of the discrepancy measured should not be clinically significant.
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Affiliation(s)
- Marta Revilla-León
- Affiliate Professor, Graduate Prosthodontics, Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Wash; Faculty and Director of Research and Digital Dentistry, Kois Center, Seattle, Wash; and Affiliate Professor, Graduate Prosthodontics, Department of Prosthodontics, School of Dental Medicine, Tufts University, Boston, Mass
| | - Miguel Gómez-Polo
- Associate Professor, Department of Conservative Dentistry and Prosthodontics, School of Dentistry, Complutense University of Madrid, Madrid, Spain.
| | | | - Abdul B Barmak
- Assistant Professor, Clinical Research and Biostatistics, Eastman Institute of Oral Health, University of Rochester Medical Center, Rochester, NY
| | - Wael Att
- Founder and Director, The Face Dental Group, Boston, Mass; and Professor, Department of Prosthodontics, University Hospital of Freiburg, Freiburg, Germany
| | - John C Kois
- Founder and Director, Kois Center, Seattle, Wash; Affiliate Professor, Graduate Prosthodontics, Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle, Wash; and Private practice, Seattle, Wash
| | - Jorge Alonso Pérez-Barquero
- Adjunct Professor, Department of Dental Medicine, Faculty of Medicine and Dentistry, University of Valencia, Valencia, Spain
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