Yazar "Yilmaz, Deniz" seçeneğine göre listele

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    Benchmarking Different Natural Language Processing Models for Their Responses to Queries on Toothsupported Fixed Dental Prostheses in Terms of Accuracy and Consistency
    (2025) Çolpak, Emine Dilara; Yilmaz, Deniz
    Aim: This study aimed to evaluate the accuracy and consistency of responses generated by four different natural language processing (NLP) models to the queries on tooth-supported fixed dental prostheses. Materials and Method: Twelve open-ended questions in Turkish were created and posed to four different NLPs according to the following models: OpenAI o3 (LRM-O), OpenAI GPT 4.5 (LLM-G), DeepSeek R1 (LRM-R), and DeepSeek V3 (LLM-V) with pre- prompts in the morning, afternoon, and evening. The responses were evaluated with a holistic rubric. For accuracy assessments, the Kruskal–Wallis H test was used. Consistency between the graders’ responses was assessed using the Brennan and Prediger coefficient and the Cohen kappa coefficient. Consistency among LLMs was assessed using the Fleiss kappa and Krippendorff alpha coefficients (p < 0.05). Results: There was no statistically significant difference in accuracy between the LRM-O, LLM-G, LRM-R, and LLM-V groups (p = 0.30). The respective accuracies of LRM-O, LLM-G, LRM-R, and LLM-V were 77.7%, 50%, 66.6%, and 77.7%. In addition, the consistency among LLMs was found to be almost perfect, whereas that of LRMs was substantial. Conclusion: Within the limitations of the study, LRMs and LLMs exhibited similar accuracy. However, the consistency among LLMs was higher than that of LRMs.
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    Bond strength of additively manufactured composite resins to dentin and titanium when bonded with dual-polymerizing resin cements
    (Mosby-Elsevier, 2024) Donmez, Mustafa Borga; Cakmak, Gulce; Yilmaz, Deniz; Schimmel, Martin; Abou-Ayash, Samir; Yilmaz, Burak; Peutzfeldt, Anne
    Statement of problem. Additively manufactured composite resins for definitive restorations have been recently introduced. The bond strength between these composite resins and different substrates has not been extensively studied. Purpose. The purpose of this in vitro study was to measure the shear bond strength (SBS) between additively manufactured composite resins and dentin and titanium substrates and compare those with the SBS between subtractively manufactured polymer-infiltrated ceramic and the same substrates (dentin and titanium), when different dual-polymerizing resin cements were used. Material and methods. One hundred and eighty cylinder-shaped specimens (& Oslash;5x5 mm) were prepared from 3 materials recommended for definitive restorations: an additively manufactured composite resin (Crowntec [CT]); an additively manufactured hybrid composite resin (VarseoSmile Crown Plus [VS]); and a subtractively manufactured polymer-infiltrated ceramic (Enamic [EN]) (n=60). Specimens were randomly divided into six subgroups to be cemented to the two substrates (dentin and titanium; n=30) with 1 of 3 resin cements (RelyX Universal, Panavia V5, and Variolink Esthetic DC) (n=10). The restoration surface to be bonded was treated according to the respective manufacturer's recommendations. Dentin surfaces were treated according to the resin cement (Scotchbond Universal Plus Adhesive for RelyX Universal, Panavia V5 Tooth Primer for Panavia V5, and Adhese Universal for Variolink Esthetic DC), while titanium surfaces were airborne-particle abraded, and only the specimens paired with Panavia V5 were treated with a ceramic primer (Clearfil Ceramic Primer Plus). SBS was measured in a universal testing machine at a crosshead speed of 1 mm/min. Failure modes were analyzed under a microscope at x12 magnification. Data were analyzed by using 2-way analysis of variance and Tukey honestly significant difference tests (a=.05). Results. When SBS to dentin was considered, only restorative material, as a main factor, had a significant effect (P<.001); EN had the highest SBS (P<.001), while the difference in SBS values of CT and VS was not significant (P=.145). As for SBS to titanium, the factors restorative material and resin cement and their interaction had a significant effect (P<.001). Within each resin cement, EN had the highest SBS to titanium (P<.001), and within each restorative material, Variolink resulted in the lowest SBS (P<.010). Overall, EN and RelyX were associated with the highest SBS to titanium (P<.013). Mixed failures were predominant in most groups. Conclusions. Regardless of the substrate or the resin cement used, the subtractively manufactured polymer-infiltrated ceramic had higher shear bond strength than the additively manufactured composite resins. The SBS of the additively manufactured composite resins, whether bonded to dentin or titanium, were not significantly different from each other. Regardless of the restorative material, Variolink DC resulted in the lowest SBS for titanium surfaces. (J Prosthet Dent 2024;132:1067.e1-e8)
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    Chatgpt Vs. Google Gemini: Assessment of Performance Regarding the Accuracy and Repeatability of Responses to Questions in Implant-Supported Prostheses
    (2025) Yilmaz, Deniz; Çolpak, Emine Dilara
    Purpose: This study aimed to assess the accuracy and repeatability of the responses of different large language models (LLMs) to questions regarding implant-supported prostheses and assess the impact of pre-prompting and the time of day. Materials and Methods: A total of 12 open-ended questions related to implant-supported prostheses were generated. The content validity of questions was verified by a specialist. Following that, questions were posed to two different LLMs: ChatGPT-4.0 and Google Gemini (morning, afternoon, and evening; with and without pre-prompt). The responses were evaluated by two expert prosthodontists with a holistic rubric. The concordance between the graders’ responses and repeated responses by ChatGPT-4.0 and Gemini was calculated using the Brennan and Prediger coefficient, Cohen’s kappa coefficient, Fleiss’s kappa, and Krippendorff’s alpha coefficients. Kruskal-Wallis, Mann-Whitney U, and independent t-test, as well as ANOVA analyses, were used to compare the responses obtained in the implementations. Results: The results displayed that the accuracies of ChatGPT and Google Gemini were 34.7% and 17.4%, respectively. The implementation of pre-prompt significantly increased accuracy in Gemini (p = 0.026). No significant difference was found according to the time of day (morning, afternoon, or evening) or inter-week implementations. In addition, inter-rater reliability and repeatability displayed high levels of consistency. Conclusions: The use of pre-prompt positively affected accuracy and repeatability in both ChatGPT and Google Gemini. However, LLMs can still produce hallucinations. Therefore, LLMs may assist clinicians, but they should be aware of these limitations.
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    Comparison of trueness and margin quality of additively and subtractively manufactured definitive resin-based laminate veneers
    (Mosby-Elsevier, 2025) Yilmaz, Deniz; Cakmak, Gulce; Gueven, Mehmet Esad; Yoon, Hyung-In; Schimmel, Martin; Yilmaz, Burak
    Statement of problem: Currently available 3-dimensional (3D) additively manufactured (AM) resins used for definitive restorations have different chemical compositions and viscosities. The fabrication trueness and margin quality of laminate veneers additively manufactured with different resins have not been extensively studied. Purpose: The purpose of this in vitro study was to evaluate the fabrication trueness and margin quality of AM and subtractively manufactured (SM) definitive resin-based laminate veneers. Material and methods: A laminate veneer restoration for a maxillary right central incisor with a 25-mu m cement space was designed to generate a reference laminate veneer standard tessellation language (STL) file (RLV-STL). This RLV-STL was used to fabricate resin-based laminate veneers (N=60) for definitive use, either using AM (a low-viscosity, urethane acrylate-based resin (C&B Permanent, AM-LV), a high-viscosity, urethane acrylate-based resin (Tera Harz TC-80DP, AM-HV), and a glass-reinforced composite resin (Crowntec, AM-S) or SM (glass-filler reinforced composite resin blocks (Tetric CAD, SM) technologies. All laminate veneers were digitized with an intraoral scanner (CEREC Primescan SW 5.2) to generate their test STL files (TLV-STLs). RLV-STL and TLV-STLs were transferred into a 3D analysis software program (Geomagic Control X), and a trueness (external, intaglio, and marginal surface) analysis was performed by using the root mean square (RMS) method. The margin quality of laminate veneers was examined visually under a stereomicroscope and graded. The Kruskal-Wallis and Dunn tests were performed to analyze the data (alpha=.05). Results: External, intaglio, and marginal RMS values showed statistically significant differences among test groups (P<.001). The SM group had the highest RMS values for the external surface (P<.001), whereas the AM-LV group had the lowest RMS values. The AM-HV group had the highest RMS values for the intaglio surface (P<.001). No significant difference was found between the SM and AM-HV groups for marginal RMS values, which were higher than for the other groups (P=.830). All average values for the axial mesial, axial distal, and incisal edge margin quality of laminate veneers were found to be similar and Grade 3 (smooth edge) in all groups. Conclusions: Regardless of the evaluated surface, the fabrication technique affected the trueness of laminate veneers. The low-viscosity AM laminate veneers and AM laminate veneers reinforced with glass fillers had higher trueness than the SM laminate veneers at all surfaces. The low-viscosity AM laminate veneers had the highest trueness on external and marginal surfaces among the test groups and had higher trueness than the high-viscosity AM laminate veneers.
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    Effect of Hydrothermal Aging on the Flexural Strength and Microhardness of Materials Used for Additive or Subtractive Manufacturing of Definitive Restorations
    (Quintessence Publishing Co Inc, 2024) Yilmaz, Deniz; Cakmak, Gulce; Guven, Mehmet Esad; Pieralli, Stefano; Yoon, Hyung-In; Revilla-Leon, Marta; Yilmaz, Burak
    Purpose: To evaluate the flexural strength (FS) and microhardness of various CAD/CAM restorative materials intended for definitive use. The effect of hydrothermal aging on the mechanical properties of these materials was also investigated. Materials and Methods: A total of 210 bar-shaped specimens (17 x 4 x 1.5 mm +/- 0.02 mm) were fabricated via either subtractive manufacturing (SM) methods-reinforced composite resin (SM-CR), polymer-infiltrated ceramic network (SM-PICN), fine-structured feldspathic ceramic (SM-FC), nanographene-reinforced polymethyl methacrylate (PMMA; SM-GPMMA), PMMA-based resin (SM-PMMA)-or additive manufacturing (AM) methods with urethane acrylate-based resins (AM-UA1 and AM-UA2). Specimens were then divided into two subgroups (nonaged or hydrothermal aging; n = 15). A three-point flexural strength test was performed, and five specimens from the nonaged group were submitted to microhardness testing. Specimens were subjected to 10,000 thermal cycles, and the measurements were repeated. Results: Regardless of aging, SM-CR had the highest FS (P <.001), followed by SM-GPMMA (P =.042). In nonaged groups, AM-UA2 had a lower FS than all other materials except SM-FC (P = 1.000). In hydrothermal aging groups, AM specimens had lower FS values than other materials, except SM-PMMA. With regard to microhardness, there was no significant difference found between any of the tested materials (P =.945) in the nonaged and hydrothermal aging groups. Conclusions: The effect of hydrothermal aging on FS varied depending on the type of restorative material. Regardless of aging condition, SM-CR showed the highest FS values, whereas SM- FC had the highest microhardness. Hydrothermal aging had no significant influence on the microhardness of the tested materials.
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    Effect of polishing and denture cleansers on the surface roughness of new-generation denture base materials and their color change after cleansing
    (Wiley, 2024) Cakmak, Guelce; Hess, Julia Anouk; Donmez, Mustafa Borga; Yilmaz, Deniz; Alhotan, Abdulaziz; Schimmel, Martin; Peutzfeldt, Anne
    Purpose: To evaluate the effect of polishing and denture cleansers on the surface roughness (Ra) of new-generation denture basematerials that are additively, subtractively, and conventionally fabricated, while also assessing their color change after cleansing. Material and Methods: One hundred and fifty disk-shaped specimens (O10 x 2 mm) were prepared from five denture base materials (one subtractively manufactured nanographene-reinforced prepolymerized polymethylmethacrylate (PMMA) (SM-GC), one subtractively manufactured prepolymerized PMMA (SM-PM), two additively manufactured denture base resins (AM-DT and AM-ND), and one heat-polymerized PMMA (CV) (n = 30). The R-a of the specimens was measured before and after conventional laboratory polishing, while color coordinates were measured after polishing. Specimens were then divided into three subgroups based on the denture cleanser: distilled water, 1% sodium hypochlorite (NaOCl), and effervescent tablet (n = 10). The R-a and color coordinates were remeasured after nine cleansing cycles over a period of 20 days. The CIEDE2000 formula was used to calculate the color differences (Delta E-00). Two-way analysis of variance (ANOVA) was used to analyze the R-a values before (n = 30) and after (n = 10) cleansing, while repeated measures ANOVA was used to analyze the R-a of material-time point pairs within each denture cleanser (n = 10). Delta E-00 data after denture cleansing was also analyzed by using two-way ANOVA (n = 10) (a = 0.05). Results: Before polishing, Ra varied significantly among the materials. SM-GC and SM-PM had the lowest and AM-ND the highest Ra values (P < 0.001). Polishing significantly reduced R-a of all materials (P < 0.001), and after polishing, Ra differences among materials were nonsignificant (P >= 0.072). Regardless of the denture cleanser, the R-a of AM-DT, AM-ND, and CV was the highest before polishing when different time points were considered (P < 0.001). After cleansing, AM-ND had the highest R-a of all the materials, regardless of the cleanser (P <= 0.017). AM-DT had higher R-a than SM-PM when distilled water (P = 0.040) and higher R-a than SM-GC, SM-PM, and CV when NaOCl was used (P < 0.001). The type of cleanser significantly influenced the R-a of AM-DT, AM-ND, and CV. For AM-DT, NaOCl led to the highest R-a and the tablet led to the lowest R-a (P <= 0.042), while for AM-ND, distilled water led to the lowest R-a (P <= 0.024). For CV, the tablet led to lower R-a than distilled water (P = 0.009). Color change varied among the materials. When distilled water was used, SM-GC had higher Delta E-00 than SM-PM and AM-DT (P <= 0.034). When NaOCl was used, AM-ND had higher Delta E-00 than SM-GC, SM-PM, and AM-DT, while CV and SM-GC had higher Delta E-00 than SM-PM and AM-DT (P = 0.039). Finally, when the tablet was used, AM-ND and CV had the highest Delta E-00, while AM-DT had lower Delta E-00 than SM-GC (P = 0.015). Conclusions: The tested materials had unacceptable surface roughness (>0.2 mu m) before polishing. Roughness decreased significantly after polishing (<0.2 mu m). Denture cleansers did not significantly affect the surface roughness of the materials, and roughness remained clinically acceptable after cleansing (<0.2 mu m). Considering previously reported color thresholds, AM-ND and CV had unacceptable color change regardless of the denture cleanser, and the effervescent tablet led to perceptible, but acceptable color change for SM-GC, SM-PM, and AM-DT.
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    Effects of 16% Carbamide Peroxide on Optical Properties of Thermally Aged Monolithic CAD-CAM Glass Ceramics with Different Surface Treatments
    (Operative Dentistry Inc, 2023) Murat, Sema; Batak, Burcu; Yilmaz, Deniz; Ozturk, Caner
    This study aimed to investigate the effects of 16% carbamide peroxide (CP) on the relative translucency parameter (RTP) and color stability of thermally aged CAD-CAM glass-ceramics with glazing or polishing. Three different CAD-CAM blocks-feldspathic (VM), lithium disilicate (IPS), and zirconia-reinforced lithium silicate ceramic (VS)-were used in this study. The specimens were divided into two groups (n=10) according to surface treatments (glazing or polishing). Bleaching treatment with 16% CP was applied to the thermally aged specimens. A spectrophotometer (VITA Easyshade Advance) was used to measure the CIE L*a*b*coordinates of the specimens on white and black backgrounds, and RTP and color difference (Delta E00) values were calculated. The surface topography of the specimens and the atomic weight of the elements were analyzed with scanning electron microscopy and energy -dispersive x-ray. The data were analyzed by using the two-way ANOVA test for Delta E00 values and two-way repeated measures ANOVA test for RTP and color parameters values (a=0.05) and the Tukey post-hoc test was used for multiple comparisons of the groups. RTP values were statistically influenced by material type, bleaching, and finishing technique, and the interaction among these factors was found to be significant (p<0.05). Delta E00 values were statistically influenced by material type, finishing technique, and the interaction among these factors was also found to be significant (p<0.05). IPS presented significantly lower RTP and Delta E00 values for both glazed and polished surfaces (p<0.05). 16% CP bleaching agent caused changes in translucency of aged VM and IPS at different levels. Glazed surfaces presented higher color stability in comparison to mechanically polished surfaces for VS (p<0.05).
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    Evaluation of color stainability of computer-aided design/computer-aided manufacturing blocks with different microstructures
    (2025) Yilmaz, Deniz; Karaağaçlıoğlu, Lale
    The stainability of ceramic materials is a critical factor in the long-term esthetic success of computer-aided design/computer-aided manufacturing (CAD/CAM) restorations. This study aimed to evaluate the color stainability of CAD/CAM ceramic blocks with different microstructures after immersion in a coffee solution for varying durations. Three types of CAD/CAM blocks—Vita Mark II (MG), Vita Suprinity ([SG] and [SP]), and Vita Enamic (EP)—were used. Finishing and polishing were performed according to the manufacturers’ instructions. CIE L*, a*, and b* values were measured at baseline (T?), and after 1 (T?), 12 (T??), and 30 (T??) days of immersion in coffee using a spectrophotometer. Color differences (?E??), ?L', ?C', and ?H' were calculated using the CIEDE2000 formula. One-way ANOVA was used to compare these values across materials. Multiple linear regression analysis was conducted to assess the influence of ?L', ?C', and ?H' on ?E?? (p<0.05). Statistically significant differences in ?E??, ?L', ?C', and ?H' values were observed at all time intervals (p=.000), except for ?H' between T?-T?? (p=.199). ?L' was the primary influencing factor for MG, SG, and SP materials, while ?H' had the greatest effect on EP over the T?–T?? interval. Within the limitations of this study, the chemical composition of the material influenced ?E??, ?L', ?C', and ?H' values. SG showed the lowest and clinically acceptable level of staining, while EP exhibited a moderate but clinically unacceptable degree of discoloration.
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    Fabrication trueness and marginal quality of additively manufactured resin-based definitive laminate veneers with different restoration thicknesses
    (Elsevier Sci Ltd, 2024) Cakmak, Guelce; Donmez, Mustafa Borga; Yilmaz, Deniz; Yoon, Hyung-In; Kahveci, Cig dem; Abou-Ayash, Samir; Yilmaz, Burak
    Objectives: To evaluate how restoration thickness (0.5 mm and 0.7 mm) affects the fabrication trueness of additively manufactured definitive resin-based laminate veneers, and to analyze the effect of restoration thickness and margin location on margin quality. Methods: Two maxillary central incisors were prepared either for a 0.5 mm- or 0.7 mm-thick laminate veneer. After acquiring the partial-arch scans of each preparation, laminate veneers were designed and stored as reference data. By using these reference data, a total of 30 resin-based laminate veneers were additively manufactured (n = 15 per thickness). All veneers were digitized and stored as test data. The reference and test data were superimposed to calculate the root mean square values at overall, external, intaglio, and marginal surfaces. The margin quality at labial, incisal, mesial, and distal surfaces was evaluated. Fabrication trueness at each surface was analyzed with independent t-tests, while 2-way analysis of variance was used to analyze the effect of thickness and margin location on margin quality (alpha = 0.05). Results: Regardless of the evaluated surface, 0.7 mm-thick veneers had lower deviations (P < 0.001). Only the margin location (P < 0.001) affected the margin quality as labial margins had the lowest quality (P < 0.001). Conclusion: Restoration thickness affected the fabrication trueness of resin-based laminate veneers as 0.7 mmthick veneers had significantly higher trueness. However, restoration thickness did not affect the margin quality and labial margins had the lowest quality. Clinical significance: Laminate veneers fabricated by using tested urethane-based acrylic resin may require less adjustment when fabricated in 0.7 mm thickness. However, marginal integrity issues may be encountered at the labial surface.
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    Fabrication Trueness, Intaglio Surface Adaptation, and Marginal Integrity of Resin- Based Onlay Restorations Fabricated by Additive and Subtractive Manufacturing
    (Quintessence Publishing Co Inc, 2024) Cakmak, Gulce; Steigmeier, David; Guven, Mehmet Esad; Yilmaz, Deniz; Schimmel, Martin; Yoon, Hyung-In; Yilmaz, Burak
    Purpose: To evaluate the fabrication trueness, intaglio surface adaptation, and marginal integrity of resin- based onlay restorations made via additive manufacturing (AM) or subtractive manufacturing (SM). Materials and Methods: An onlay restoration was designed (DentalCAD Galway 3.0) and saved as an STL file to generate a design STL file (DO-STL). Using this design, 45 onlays were fabricated either with AM (3D-printed resin for definitive [AM-D; Tera Harz TC- 80DP] and interim [AM- I; Freeprint temp] restorations) or SM (composite resin, Tetric CAD) technologies. Onlays were scanned with an intraoral scanner (CEREC Primescan SW 5.2), and the scans were saved as test STL files (TO-STLs). For trueness evaluation, TO-STLs were superimposed over the DO-STL, and root mean square (RMS) values of overall and intaglio surfaces were measured (Geomagic Control X). For the intaglio surface adaptation and marginal integrity, a triple-scan protocol was performed. Kolmogorov-Smirnov, one- way ANOVA, and post-hoc Tukey honestly significant difference tests were used to analyze data (alpha =.05). Results: RMS values of intaglio and overall surfaces, intaglio adaptation, and marginal integrity varied among test groups (P <.001). AM- D had the greatest overall surface RMS (P <.001), while SM had the greatest intaglio surface RMS (P <.001). SM had the highest average distance deviations for intaglio surface adaptation and marginal integrity, whereas AM-D had the lowest (P <.001). Conclusions: AM-D onlays showed lower overall trueness than AM-I onlays and SM definitive onlays. However, AM-D onlays presented high intaglio surface trueness, intaglio surface adaptation, and marginal integrity.
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    Influence of intraoral scanner and finish line location on the fabrication trueness and margin quality of additively manufactured laminate veneers fabricated with a completely digital workflow
    (Mosby-Elsevier, 2024) Cakmak, Guelce; Chebaro, Jad; Donmez, Mustafa Borga; Yilmaz, Deniz; Yoon, Hyung-In; Kahveci, Cigdem; Schimmel, Martin
    Statement of problem. Knowledge of the fabrication trueness and margin quality of additively manufactured (AM) laminate veneers (LVs) when different intraoral scanners (IOSs) and finish line locations are used is limited. Purpose. The purpose of this in vitro study was to evaluate the fabrication trueness and margin quality of AM LVs with different finish line locations digitized by using different IOSs. Material and methods. An LV preparation with a subgingival (sub), equigingival (equi), or supragingival (supra) finish line was performed on 3 identical maxillary right central incisor typodont teeth. Each preparation was digitized by using 2 IOSs, (CEREC Primescan [PS] and TRIOS 3 [TS]), and a reference LV for each finish line-IOS pair (n=6) was designed. A total of 90 LVs were fabricated by using these files and urethane acrylate-based definitive resin (Tera Harz TC-80DP) (n=15). Each LV was then digitized by using PS to evaluate fabrication trueness (overall, external, intaglio, and marginal surfaces). Each LV was also qualitatively evaluated under a stereomicroscope (x60), and the cervical and incisal margin quality was graded. Fabrication trueness and cervical margin quality were evaluated by using 2 -way analysis of variance, while Kruskal-Wallis and Mann Whitney -U tests were used to evaluate incisal margin quality (alpha=.05). Results. The interaction between the IOS type and the finish line location affected measured deviations at each surface (P <=.020). PS -sub and TS -supra had higher overall trueness than their counterparts. and the subgingival finish line resulted in the lowest trueness (P <=.005). PS and the subgingival finish line led to the lowest trueness of the external surface (P <=.001). TS -sub had the lowest intaglio surface trueness among the TS subgroups, and PS -sub had higher trueness than TS -sub (P<.001). PS -sub and PS -supra had higher marginal surface trueness than their TS counterparts (P<.001). TS resulted in higher cervical margin quality (P=.001). Conclusions. Regardless of the IOS tested, subgingival finish lines resulted in the lowest trueness. The effect of IOS on the measured deviations varied according to the surface evaluated and finish line location. The cervical margin quality of AM LVs was higher when TS was used. (J Prosthet Dent 2024;131:313.e1 -e9)
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    Trueness and precision of combined healing abutment scan body system scans at different sites of maxilla after multiple repositioning of the scan body
    (Elsevier Sci Ltd, 2023) Donmez, Mustafa Borga; Guven, Mehmet Esad; Yilmaz, Deniz; Abou-Ayash, Samir; Cakmak, Gulce; Yilmaz, Burak
    Objectives: To evaluate the accuracy of the scans of the combined healing abutment-scan body (CHA-SB) system located at different sites of the maxilla when SBs are replaced in between each scan.Methods: Three SBs were seated into HAs located at the central incisor, first premolar, and first molar sites of a maxillary model inside a phantom head, and the model was scanned extraorally (CEREC Primescan SW 5.2). This procedure was repeated with new SBs until a total of 10 scans were performed. Standard tessellation language files of CHA-SBs at each implant location were isolated, transferred into analysis software (Geomagic Control X), and superimposed over the proprietary library files to analyze surface (root mean square), linear, and angular deviations. Trueness and precision were evaluated with one-way analysis of variance and Tukey tests. The correlation between surface and angular deviations was analyzed with Pearson's correlation (alpha=0.05).Results: Molar implant scans had the highest surface and angular deviations (P <=.006), while central incisor implant scans had higher precision (surface deviations) than premolar implant scans (P=.041). Premolar implant scans had higher accuracy than central incisor implant scans on the y-axis (P <=.029). Central incisor implant scans had the highest accuracy on the z-axis (P <=.018). A strong positive correlation was observed between surface and angular deviations (r = 0.864, P<.001).Conclusion: Central incisor implant scans mostly had high accuracy and molar implant scans mostly had lower trueness. SBs were mostly positioned apically; however, the effect of SB replacement can be considered small as measured deviations were similar to those in previous studies and the precision of scans was high.Clinical Significance: Repositioning of scan bodies into healing abutments would be expected to result in similar single crown positioning regardless of the location of the implant, considering high scan precision with the healing abutment-scan body system. The duration of the chairside adjustments of crowns in the posterior maxilla may be longer than those in the anterior region.