Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry最新文献

{"title":"Fracture resistance of zirconia fixed dental prostheses after low-temperature degradation and/or cyclic fatigue.","authors":"Yuqi Li, Youdong Zhang, Yun Lan, Mingming Huang, Jiao Wen, Jianmin Han","doi":"10.1111/jopr.70227","DOIUrl":"https://doi.org/10.1111/jopr.70227","url":null,"abstract":"<p><strong>Purpose: </strong>Monolithic zirconia fixed dental prostheses (FDPs) are widely used because of their favorable esthetic and mechanical properties. Hydrothermal aging and cyclic fatigue may interact to affect monolithic zirconia FDPs, but evidence from anatomically shaped multi-unit restorations remains limited. This study evaluated fracture resistance, phase transformation, and failure characteristics of three zirconia restorative systems after simulated service exposure.</p><p><strong>Materials and methods: </strong>Ninety-six three-unit FDPs were fabricated from self-glazed zirconia (SG), De Corematrix zirconia (DZ), and Lava zirconia (LZ). For each system, the FDPs were divided into four exposure conditions (n = 8): control, cyclic fatigue, low-temperature degradation (LTD), and LTD followed by cyclic fatigue. All specimens were subsequently subjected to load-to-failure testing. Raman spectroscopy and scanning electron microscopy characterized phase transformation and microstructural features.</p><p><strong>Results: </strong>All cyclically loaded FDPs survived 5 × 10⁶ cycles without macroscopic failure. SG showed the highest control fracture resistance. Cyclic fatigue alone produced little change in SG, whereas LTD and combined exposure markedly reduced its fracture resistance. No exposure-related differences were detected for DZ or LZ, although equivalence was not established. Monoclinic-phase formation was not detected after cyclic fatigue alone but was observed after LTD in all systems and was greater after combined exposure.</p><p><strong>Conclusions: </strong>Simulated service exposure affected the zirconia restorative systems differently. SG exhibited the highest initial fracture resistance but was more susceptible to hydrothermal aging. For DZ and LZ, no differences were detected under the present sample size, but stability was not established. All tested FDPs tolerated clinical-level loads, even after long-term service simulations.</p>","PeriodicalId":49152,"journal":{"name":"Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148907808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of tray relief amount and impression material type on dimensional accuracy of complete denture impressions.","authors":"Minji Sun, Jae Hoon Lee, So Hee Kim, Jihoon Shin, Jaeyoung Kim","doi":"10.1111/jopr.70230","DOIUrl":"https://doi.org/10.1111/jopr.70230","url":null,"abstract":"<p><strong>Purpose: </strong>The purpose of this study was to evaluate the combined effects of tray relief amount and impression materials on the three-dimensional (3D) accuracy of complete denture impressions.</p><p><strong>Materials and methods: </strong>A fully edentulous maxillary cast and corresponding custom trays were digitally designed with a uniform 1.0 mm relief, and additional midpalatal relief of 0, 1.5, and 3 mm was incorporated. Impressions were made using four elastomeric impression materials and poured with Type IV dental stone. 3D surface deviation analysis was performed, and the average deviation and maximum absolute deviation (MAD) were calculated.</p><p><strong>Results: </strong>Across all impression materials, both the average deviation and the MAD increased as the midpalatal relief amount increased from 0 to 1.5 and 3 mm. Significant differences among the three relief conditions were confirmed for all materials (p < 0.05), and the post hoc test showed that every material exhibited a significant increase between the 0 and 3 mm conditions. Across all relief levels, no significant differences in average deviation were observed among the four materials. For MAD, a material-dependent difference was identified only at the 1.5 mm relief condition (p < 0.001).</p><p><strong>Conclusions: </strong>The results demonstrated that polymerization shrinkage of elastomeric impression materials can produce localized microrelief within relieved regions of edentulous impressions, resulting in polymerization-induced microrelief. Both the relief amount and the material type influenced the magnitude of shrinkage-related dimensional change, suggesting that the interaction between tray relief and material behavior affects impression accuracy in edentulous patients.</p>","PeriodicalId":49152,"journal":{"name":"Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148901445","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The accuracy of reverse scan body technique for capturing full-arch digital implant impressions: An in vitro study.","authors":"Ahmed Elsayyad, Christopher Wyatt, Ross Bryant, Mohamed Gebril","doi":"10.1111/jopr.70235","DOIUrl":"https://doi.org/10.1111/jopr.70235","url":null,"abstract":"<p><strong>Purpose: </strong>This study assessed the accuracy of full-arch implant prostheses milled using a reverse scan body (RSB) impression technique compared to those generated from a digitized master cast using a desktop scanner.</p><p><strong>Materials and methods: </strong>A mandibular All-on-4 master cast was created and digitized using a reference desktop scanner. For each RSB scan (Group 1), an interim milled polymethylmethacrylate (PMMA) prosthesis was picked up from the cast, RSBs were hand-tightened, and captured using an intraoral scanner (IOS). For Group 2, abutment-level scan bodies were hand-tightened into the multiunit abutments (MUAs) of the master cast and scanned using a desktop scanner. The deviation between each resultant scan from each group was digitally compared to the MUAs position of the digitized master cast. The digital deviation and clinical passivity (modified one screw and screw resistance tests) between the milled zirconia prosthesis from each group were compared to the master cast.</p><p><strong>Results: </strong>The deviation of the RSB-IOS impression (median = 0.07 mm) was statistically significant (p = 0.015) when compared to the desktop scan impression (median = 0.05 mm). For the milled zirconia prostheses, a similar statistically significant difference was observed with corresponding deviation values of 0.15 ± 0.02 and 0.11 ± 0.01 mm for the RSB and the desktop scanner groups, respectively. The passivity of the zirconia prostheses on the master cast showed variability when judged by three outcome assessors.</p><p><strong>Conclusion: </strong>The RSB technique was inferior to the desktop scan in terms of digital impression and definitive prostheses accuracy. However, the RSB technique produced zirconia prostheses within the clinically acceptable deviation value of 0.15 mm.</p>","PeriodicalId":49152,"journal":{"name":"Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148901397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Retention characteristics of individually milled bar systems with customized patrices: An in vitro comparison of electroplated and friction-based retention concepts.","authors":"Helene Bacher, Sebastian Hinz, Tobias Bensel, Daniel Voigt, Dean Morton, Arne F Boeckler","doi":"10.1111/jopr.70233","DOIUrl":"https://doi.org/10.1111/jopr.70233","url":null,"abstract":"<p><strong>Purpose: </strong>This in vitro study examined the initial and long-term retention behavior of individually milled bar (IMB) systems combined with customized patrices (CPs), contrasting electroplated patrices (EP), and friction pin patrices (FPP) concepts. Retention values were related to a previously reported laboratory reference threshold of 5 N. Given the exploratory nature of the design, the study aimed to describe material-dependent trends rather than to establish clinical sufficiency.</p><p><strong>Materials and methods: </strong>Seven IMB-CP combinations were fabricated-four with EP (gold, non-precious alloy, titanium, and zirconia) and three with FPP (non-precious alloy, titanium, and zirconia) (n = 5 per group). Each bar was mounted on two implants embedded in epoxy resin casts and subjected to 5000 insertion-removal cycles in artificial saliva (23°C) using a universal testing machine. Retention forces were continuously recorded, and surface alterations were assessed by profilometry, light microscopy, and environmental scanning electron microscopy. Material wear was determined gravimetrically. Data were analyzed after assessment of normality (Shapiro-Wilk); initial and final retention forces were compared within groups using paired t-tests or Wilcoxon signed-rank tests (α = 0.05). No inferential comparisons between materials or retention concepts were performed; differences between groups are reported descriptively.</p><p><strong>Results: </strong>Initial retention ranged from 5.4 N (titanium-titanium FPP) to 21.7 N (non-precious EP), all exceeding the 5 N laboratory reference threshold. After cyclic loading, final retention ranged from 2.4 N (TF) to 18.5 N (NG). The change in retention (ΔF = F_final - F_initial) varied from -10.1 to +2.1 N across groups. Surface roughness decreased for most EP systems, whereas FPP systems showed greater wear and predictable retention loss. Material change ranged from 8 to 34 µg (IMB) and 36 to 180 µg (CP).</p><p><strong>Conclusions: </strong>Under the tested laboratory conditions, all IMB-CP systems showed initial retention forces above the 5 N reference threshold. After 5000 insertion-removal cycles, the titanium-titanium FPP combination exhibited the lowest retention and fell below this threshold, whereas the remaining systems maintained retention values above it. EP showed stable or slightly increased retention with minimal measured wear, whereas FPP showed greater, predictable wear-related retention loss. These exploratory observations demonstrate that material pairing plays an important role in retention behavior under in vitro conditions, whereas clinical performance, maintenance requirements, and long-term success should be evaluated in future clinical studies.</p>","PeriodicalId":49152,"journal":{"name":"Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148892821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Clinical implications of misfit in multiunit implant-supported fixed dental prostheses: A systematic review.","authors":"Zijing He, Vincent Bennani, John M Aarts, Joanne Jung Eun Choi, Arthi Veerasamy","doi":"10.1111/jopr.70231","DOIUrl":"https://doi.org/10.1111/jopr.70231","url":null,"abstract":"<p><strong>Purpose: </strong>This systematic review aimed to evaluate the long-term effects of misfit on the clinical outcomes of multiunit implant-supported fixed dental prostheses (ISFDPs).</p><p><strong>Methods: </strong>An electronic literature search was conducted up to December 2025 across five databases: MEDLINE (via Ovid), Embase (via Ovid), Web of Science, the Cochrane Library, and Scopus. Eligible articles were selected based on predefined inclusion and exclusion criteria, and relevant data were extracted. The Newcastle-Ottawa Scale was used to evaluate the methodological quality of the included studies.</p><p><strong>Results: </strong>After screening and applying the eligibility criteria, four articles were identified from the initial 2179 records. Two additional articles were identified through a manual search, bringing the total to six. Although quality assessment indicated that all six studies were at low risk of bias, the comparability domain was weak in most due to limited control of confounding factors. Clinical outcomes in the included studies were reported across four domains: implant cumulative survival rate, screw loosening or fracture, prosthesis-related complications, and peri-implant bone loss. Only one study reported a significantly higher incidence of screw complications in ISFDPs with greater misfit (p = 0.005), whereas most studies did not find a consistent association between misfit and clinical outcomes.</p><p><strong>Conclusions: </strong>Evidence regarding the clinical implications of misfit in multiunit ISFDPs is limited, with few long-term studies and insufficient control for confounding factors. Limited evidence suggests that greater misfit may be associated with screw complications, whereas no clear association was observed between misfit and peri-implant bone loss.</p>","PeriodicalId":49152,"journal":{"name":"Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148889036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accuracy (trueness and precision) of two handheld scanners and a smartphone for three-dimensional facial scanning: An in vivo study.","authors":"Gaizka Erkizia, Xabier Amezua, Mikel Iturrate, Eneko Solaberrieta","doi":"10.1111/jopr.70228","DOIUrl":"https://doi.org/10.1111/jopr.70228","url":null,"abstract":"<p><strong>Purpose: </strong>The aim of this in vivo study was to evaluate and compare the accuracy (trueness and precision) of three portable facial scanning methods: a professional handheld structured-light scanner (P-HS), a low-cost handheld structured-light scanner (LC-HS), and a smartphone with a depth-sensing camera (SP).</p><p><strong>Materials and methods: </strong>Twelve adult volunteers were recruited. Seventeen facial soft-tissue landmarks were marked with adhesive fiducials, and 12 inter-landmark distances were measured. Ten repeated facial scans were acquired from each participant with each method, plus reference scans from an industrial reference scanner. The relative error (RE) was calculated, and trueness and precision were expressed as the mean (Mean-RE) and standard deviation (SD-RE) of REs per participant, distance, and method. The methods were compared using linear mixed-effects models, with pairwise comparisons adjusted by the Holm method (α = 0.05).</p><p><strong>Results: </strong>Statistically significant differences were found in the trueness and precision. The P-HS was the most accurate. The P-HS and SP showed comparable precision, about twice that of the LC-HS, which was the least precise and tended to overestimate. Despite a near-zero net trueness, the SP produced the largest deviations at individual distances. Differences between the trueness and precision of P-HS and SP were not statistically significant.</p><p><strong>Conclusions: </strong>The facial scanning method significantly affected accuracy. The P-HS best suits high-fidelity workflows; the LC-HS remained within clinically acceptable limits in other studies for less demanding tasks; and the SP was least accurate where point-to-point fidelity is required. Method selection should follow the accuracy each workflow requires.</p>","PeriodicalId":49152,"journal":{"name":"Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148888996","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative evaluation of artificial intelligence-assisted smile designs: Aesthetic preferences among dental specialists and laypeople.","authors":"Ghaida Mohammed Alsulaiman, Rakan Baaj, Rasha Altahan","doi":"10.1111/jopr.70221","DOIUrl":"https://doi.org/10.1111/jopr.70221","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Purpose: &lt;/strong&gt;To evaluate aesthetic preferences for artificial intelligence (AI)-assisted smile designs produced using four digital smile design software platforms, and to explore associations between these preferences and demographic factors, among dental specialists and laypeople.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Materials and methods: &lt;/strong&gt;A cross-sectional study was conducted to assess aesthetic preferences for AI-assisted smile designs among dental specialists and laypeople. Photographs of 10 standardized models were processed through four digital smile design software platforms: Smilefy, Smilecloud, DTS PRO, and Trios Smile Design. A single prosthodontist reviewed each automated output and adjusted tooth shape, color, midline, gingival contour, and occlusal plane where needed to conform to clinical norms; outputs are therefore best described as AI-assisted rather than fully automated. Each output was labeled A-D to blind participants to the software used; this letter assignment was shuffled independently for each of the 10 model sets rather than following a single fixed layout, though the specific mapping used per set was not formally logged. Participants ranked the four outputs per model from 1 (most aesthetic) to 4 (least aesthetic) using a blinded, pretested questionnaire. Of the participants recruited, at least partial ranking data were available for an analytic sample of 78 dental specialists and 86 laypeople (164 total; demographic data were available for 76 and 85, respectively). Because rankings were ordinal, clustered within participants, and forced-choice, aesthetic preference was analyzed using the Friedman test with Kendall's coefficient of concordance (W) as an effect size, followed by Wilcoxon signed-rank pairwise comparisons with Holm correction. Associations between preference and professional group, age, and gender were examined using Mann-Whitney U and Kruskal-Wallis tests (Holm-corrected), applied to each software's mean rank.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;Rankings differed significantly across the four software platforms (Friedman χ&lt;sup&gt;2&lt;/sup&gt; = 349.8, df = 3, p &lt; 0.001; Kendall's W = 0.71, indicating strong agreement). Smilefy and Smilecloud were the most preferred designs overall (mean ranks 1.78 and 1.90, respectively, out of 4), while Trios was the least preferred (mean rank 3.55). Specialists showed significantly stronger relative preference for Smilecloud than laypeople did (rank-biserial r = 0.37, Holm-adjusted p &lt; 0.001), while laypeople were relatively more tolerant of Trios than specialists were (r = -0.44, Holm-adjusted p &lt; 0.001). Within specialists, preference against Trios strengthened significantly with age (Kruskal-Wallis H = 26.2, p &lt; 0.001, ε&lt;sup&gt;2&lt;/sup&gt; = 0.32); no other age or gender association survived correction for multiple comparisons in either group.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions: &lt;/strong&gt;Aesthetic preferences for AI-assisted smile designs differed meaningfully between software platforms and, to","PeriodicalId":49152,"journal":{"name":"Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148867317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of high-speed sintering on the translucency and color of dental zirconia with different shades and yttria contents.","authors":"Zidu Zeng, Nupur Patel, Yijing Su, Yu Zhang","doi":"10.1111/jopr.70215","DOIUrl":"https://doi.org/10.1111/jopr.70215","url":null,"abstract":"<p><strong>Purpose: </strong>This study evaluated the effects of high-speed sintering on the translucency and color of various yttria-stabilized zirconia (YSZ) compositions and identified factors influencing these properties to improve clinical predictability.</p><p><strong>Materials and methods: </strong>A total of 144 disc-shaped specimens fabricated from 3YSZ, 4YSZ, and 5YSZ pucks in shades B1, A3, and C4 were sintered using conventional (∼12 h) or high-speed (∼18 min) protocols. Specimens were polished to a 0.5 µm finish and measured Ø13.75 mm × 1 mm. Porosity, phase content, translucency, color, and elemental composition were quantified (n = 8). Normality was assessed using the Shapiro-Wilk test. Pairwise comparisons were performed using Wilcoxon rank-sum tests where appropriate. The effects of shade, yttria content, sintering protocol, and their interactions were evaluated using factorial ANOVA (α = 0.05).</p><p><strong>Results: </strong>High-speed significantly reduced translucency and diminished the translucency advantage of 5YSZ, particularly in darker shades. The reduced translucency was attributed to increased porosity. High-speed also produced lighter specimens (higher L^* values) with lower a^* and b^* values, indicating a shift toward greener, less yellow color coordinates. Color differences (ΔE₀₀) were greatest in C4-shaded specimens. Additionally, a distinct light-dark subgrouping was observed within the 4YSZ-B1 high-speed condition. Compositional analysis showed that HS reduced Fe₂O₃ levels while maintaining NiO, suggesting that color changes may be associated with Fe₂O₃ instability and increased porosity.</p><p><strong>Conclusions: </strong>High-speed reduced translucency and altered clinically perceptible color in dental zirconia, especially in high-yttria contents and darker shades.</p>","PeriodicalId":49152,"journal":{"name":"Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148800489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of implant configuration on stress distribution in quad zygoma implant systems: A finite element analysis.","authors":"Ercin Samunahmetoglu, Ilgın Ari, Arzum Yilmaz","doi":"10.1111/jopr.70225","DOIUrl":"https://doi.org/10.1111/jopr.70225","url":null,"abstract":"<p><strong>Purpose: </strong>This study aimed to evaluate the effect of different zygomatic implant configurations on the biomechanical behavior of implant-supported prosthetic systems under varying bone conditions using finite element analysis.</p><p><strong>Materials and methods: </strong>Four three-dimensional (3D) finite element models were developed based on two different anatomical conditions representing Zygoma Anatomy Guided Approach (ZAGA) Type 1 and Type 3. In each ZAGA type, two implant configurations were created by positioning zygomatic implants in different regions: lateral incisor-first molar and first premolar-first molar. All models were subjected to vertical and oblique loading conditions. Stress distribution in the peri-implant bone, implants, abutments, and metal framework, as well as implant displacement, was analyzed.</p><p><strong>Results: </strong>Under vertical loading conditions, Models 2 and 4 demonstrated lower stress values and more balanced load distribution, whereas Models 1 and 3 exhibited higher stress concentrations. In contrast, under oblique loading conditions, Models 1 and 3 showed more favorable stress values compared to Models 2 and 4. Implant displacement values were generally higher in Models 2 and 4. Within the limitations of the present finite element analysis, overall biomechanical response patterns were broadly comparable between the ZAGA Type 1 and Type 3 conditions.</p><p><strong>Conclusion: </strong>Implant configuration appeared to influence the biomechanical behavior of quad zygomatic implant systems under the tested loading conditions. Models 1 and 3 generally showed a more favorable response under oblique loading, whereas the corresponding models in ZAGA Type 1 and Type 3 exhibited broadly comparable biomechanical patterns.</p>","PeriodicalId":49152,"journal":{"name":"Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148800491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of scanner type and prosthesis design-luting protocol combinations on the passive fit of interim implant-supported complete-arch fixed dental prostheses.","authors":"Daizo Ishiguro, Mohamed Sherif Omar, Wei-Shao Lin, Toshiki Nagai","doi":"10.1111/jopr.70218","DOIUrl":"https://doi.org/10.1111/jopr.70218","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the effects of scanner type and prosthesis design-luting protocol combinations on the passive fit of interim implant-supported complete-arch fixed dental prostheses (ISCFDPs) fabricated using a non-calibrated splinting grammetry system (OptiSplint). The null hypothesis was that scanner type and prosthesis design-luting protocol combinations would not affect the passive fit of interim ISCFDPs.</p><p><strong>Materials and methods: </strong>This in vitro 2 × 3 factorial study utilized a maxillary edentulous FP-3 master cast with 4 multiunit abutment (MUA) analogs. Extraoral scans of the OptiSplint assembly were obtained using either an intraoral scanner (IOS-OptiSplint) or a laboratory scanner (Lab-OptiSplint). Each scanning method was combined with each of the three prosthesis design-luting protocol combinations: (1) Ti-base with freehand cementation, (2) Ti-base cementation on a verification cast, and (3) Direct-to-MUA design, resulting in six experimental groups (n = 10 per group; N = 60). All prostheses were milled from pre-polymerized polymethylmethacrylate (PMMA) pucks using a five-axis milling unit. All PMMA ISCFDPs were evaluated for passive fit on the master cast using the screw-resistance test by two calibrated examiners, with discrepancies resolved by a third. Misfit was determined when incomplete seating or abnormal resistance was detected during sequential screw tightening. Inter-examiner reliability was assessed using Cohen's kappa, and misfit rates were compared via Fisher's exact tests (α = 0.05).</p><p><strong>Results: </strong>Inter-examiner agreement was excellent (98%; κ = 0.95). Laboratory scanning achieved complete passive fit across all three prosthesis design-luting protocol combinations. With the IOS workflow, Ti-base on Cast demonstrated 0% misfit, Ti-base Freehand exhibited 30% misfit, and Direct-to-MUA demonstrated 100% misfit. Group 3 exhibited a significantly higher misfit frequency than all other groups (p < 0.001), whereas no other pairwise comparisons were significant.</p><p><strong>Conclusion: </strong>Laboratory scanning of a non-calibrated splinting grammetry system was associated with consistently complete passive fit across all groups. It may provide a predictable approach for achieving passive fit in complete-arch interim prostheses. Extraoral scanning with an intraoral scanner yielded variable results, underscoring the value of verification-cast cementation when using Ti-bases. Within the limitations of this study, the results suggest that Direct-to-MUA workflows may require laboratory-based scanning when using the evaluated systems.</p>","PeriodicalId":49152,"journal":{"name":"Journal of Prosthodontics-Implant Esthetic and Reconstructive Dentistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148800452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}