Journal of Prosthetic Dentistry最新文献

{"title":"Influence of interdental space and operator experience on the accuracy, scanning time, and number of photograms of veneer preparations digitized by using an intraoral scanner.","authors":"Sara Garcia-Gomez, Jesús Maneiro-Lojo, Jorge Alonso Pérez-Barquero, John C Kois, Lucía Fernandez-Estevan, Marta Revilla-León","doi":"10.1016/j.prosdent.2025.02.011","DOIUrl":"https://doi.org/10.1016/j.prosdent.2025.02.011","url":null,"abstract":"<p><strong>Statement of problem: </strong>Studies analyzing the accuracy of intraoral scanners (IOSs) for fabricating veneer restorations are scarce. Also, the space between tooth preparations significantly impacts the accuracy of IOSs. The influence of interdental space on the accuracy of veneer preparations digitized by using IOSs remains uncertain.</p><p><strong>Purpose: </strong>The purpose of the present in vitro study was to assess the influence of interdental spaces and operator experience on the accuracy, scanning time, and number of photograms of an IOS for acquiring the virtual definitive casts for fabricating 2 adjacent veneer restorations.</p><p><strong>Material and methods: </strong>A maxillary model with the 6 anterior teeth with a veneer preparation on both central incisors was virtually design. Three casts were printed each with a different interdental space between the preparations: 0.5, 1.0, and 1.5 mm. Each cast was scanned with an IOS (TRIOS 3) by an experienced and an inexperienced operator (n=10). The scanning time and number of photograms were registered. Linear measurements were obtained between the mesial surfaces of both veneer preparations in the virtual reference casts and experimental scans aiming to assess the interspace reproduction capabilities of each subgroup tested. Specimens with a bridge scanning error were registered. Two-way ANOVA and pairwise multiple comparisons were used to analyze trueness, scanning time, and number of photograms (α=.05). Levene and pairwise comparisons using Wilcoxon Rank sum tests were used to analyze precision (α=.05).</p><p><strong>Results: </strong>All the specimens of the InExp-0.5 subgroup and 30% of scans in the InExp-0.5 subgroup had a bridge scanning error. Significant trueness, precision, scanning time, and number of photograms discrepancies were found among the groups (P<.001) and subgroups (P<.001), with a significant interaction between group×subgroup (P<.001). In the 0.5 group, there were trueness (P<.001) and precision discrepancies between the experienced and inexperienced operator. The experienced operator demonstrated better trueness and precision scanning the 0.5-mm cast when compared with the other reference casts (P<.001). The inexperienced operator revealed lower trueness when scanning the 0.5-mm cast when compared with the 1.0- (P<.001) and 1.5-mm (P<.001) casts. Scanning time discrepancies were revealed between the operators in the 1.0 (P<.001) and 1.5 groups (P<.001). For the inexperienced operator, the 1.0 and 1.5 groups (P<.001) were significantly different. Number of photogram discrepancies were revealed between the operators in the 1.0 group (P<.001) and 1.5 group (P<.001). Additionally, for the inexperienced operator, the 1.0 and 1.5 groups were significantly different (P<.001).</p><p><strong>Conclusions: </strong>The interdental spaces and operator experience impacted the scanning accuracy, scanning time, and number of photograms of the IOS tested. The ine","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586040","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":"Detection of the initial gap at different implant-abutment connections.","authors":"Eduardo Anitua, Ricardo Tejero, Mikel Armentia, Iker Fernández-de-Gobeo, Luis Saracho","doi":"10.1016/j.prosdent.2025.02.013","DOIUrl":"https://doi.org/10.1016/j.prosdent.2025.02.013","url":null,"abstract":"<p><strong>Statement of problem: </strong>The seal at the implant-abutment connection (IAC) is crucial for ensuring implant-prosthetic function and reducing the risk of peri-implant diseases. An accurate determination of the first IAC gap under realistic dynamic-loading conditions is needed to investigate current and future IAC designs.</p><p><strong>Purpose: </strong>The purpose of this in vitro study was to use a novel method of determining the load and probability of occurrence of the elastic first IAC gap that overcomes most of the limitations of the representative IACs currently available.</p><p><strong>Material and methods: </strong>Three flat-straight and 4 conical-tapered connections with varying abutment cone angles with 8 specimens per configuration (n=8) were tested with an in situ loading experiment underwater by following the International Organization for Standardization (ISO) 14801 standard. Before load application, the IACs were filled with toluidine, and the screws tightened to 35 Ncm. Incremental loading of 20 N was applied over 1000 cycles until leakage was detected by a video recording macro-equipped camera. Differences between the means were determined by 1-way ANOVA (α=.05). The probability of gap occurrence was calculated from the data obtained based on the maximum occlusal force values reported in literature.</p><p><strong>Results: </strong>The method allowed the detection of the first IAC gap in the elastic regime. Flat connections showed a linear relationship between connection diameter and the first gap load ranging from 140.0 ±21.4 N (Ø3.0 mm) to 255.0 ±31.6 N (Ø4.1 mm). On Ø3.5 mm connections, the gap at flat connections opened at 193.8 ±22.0 N, while, at conical connections, the loads needed were significantly lower and the dispersion higher, irrespective of the angle between the abutment and the implant connection cones: 135.0 ±80.5 N (0 degrees), 100.0 ±54.5 N (0.4 degrees, P<.05), 77.5 ±37.7 N (0.8 degrees, P<.05) and 82.5 ±49.5 N (1.2 degrees, P<.05). Consequently, conical connections had a higher probability of gaps, particularly in the posterior zone, ranging from 8.2% to 29.0% of the reported mastication force.</p><p><strong>Conclusions: </strong>This innovative in situ leakage detection method enabled the identification of disparities in the masticatory load at which initial gaps occurred across various flat and conical IAC configurations.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143585997","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 proximal box elevation on microleakage in 3Y-TZP zirconia ceramic fixed dental prostheses after thermomechanical loading: A laboratory study.","authors":"Monika Roider, Matthias Kern, Nicole Passia","doi":"10.1016/j.prosdent.2025.01.042","DOIUrl":"https://doi.org/10.1016/j.prosdent.2025.01.042","url":null,"abstract":"<p><strong>Statement of problem: </strong>Deep subgingival defects at the abutment teeth for fixed dental prostheses (FDPs) are a common problem in prosthodontics. Surgical crown lengthening or orthodontic extrusion of the abutment teeth have been recommended treatment options. However, disadvantages such as extended treatment time, treatment costs, or surgical problems have to be considered. Proximal box elevation has been proposed as an alternative, but microleakage studies are lacking.</p><p><strong>Purpose: </strong>The purpose of this in vitro study was to investigate the influence of proximal box elevation (PBE) and conventional foundation restoration on the microleakage of 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) ceramic FDPs after thermomechanical loading (TML).</p><p><strong>Material and methods: </strong>Sixteen molars and 48 premolars were divided into 4 groups (n=8). Either fixed-to-fixed (premolar, molar) or cantilever FDPs (premolar, premolar) were fabricated. The pontic of both groups had a mesiodistal width of 7 mm. The proximal foundation restorations were placed using a self-etch adhesive system and a dual-polymerizing composite resin, and a standardized tooth preparation design was carried out. All FDPs were adhesively luted and subjected to TML (1.2 million cycles, 5/55 °C, 49 N). After TML, all specimens were placed in fuchsin and then sectioned in a sagittal direction. The sections were evaluated with respect to the penetration depth of the dye by light microscopy at 4 different interfaces: tooth and luting composite resin (TC), luting composite resin and restoration (CR), tooth and foundation restoration (TB), foundation restoration and luting composite resin (BC). As data were not normally distributed, nonparametric tests were used for statistical analysis (α=.05).</p><p><strong>Results: </strong>Statistically significant differences were observed between the PBE and the control group (P<.05). Microleakage at the TB interface was detectable in all specimens of the PBE group, while 84.4% of the specimens of the control group showed leakage at the TC and TB interfaces. Leakage was detected at the CR interface in 3.1% of all specimens. No leakage was observed at the interface BC. Additionally, statistically significant differences were found within the same study specimen between the control (conventional foundation restoration) and the study side (PBE) (P<.05).</p><p><strong>Conclusions: </strong>Irrespective of the pretreatment (experimental PBE or conventional foundation restoration), the adhesive bond of the foundation restoration and the luting composite resin to the dentin represented a limiting factor with regard to microleakage in fixed-to-fixed and cantilever FDPs. PBE was more frequently affected by microleakage than a conventional foundation restoration.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586015","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":"Large Language Models in peri-implant disease: How well do they perform?","authors":"Vasiliki P Koidou, Georgios S Chatzopoulos, Lazaros Tsalikis, Eleutherios G Kaklamanos","doi":"10.1016/j.prosdent.2025.02.008","DOIUrl":"https://doi.org/10.1016/j.prosdent.2025.02.008","url":null,"abstract":"<p><strong>Statement of problem: </strong>Artificial intelligence (AI) has gained significant recent attention and several AI applications, such as the Large Language Models (LLMs) are promising for use in clinical medicine and dentistry. Nevertheless, assessing the performance of LLMs is essential to identify potential inaccuracies or even prevent harmful outcomes.</p><p><strong>Purpose: </strong>The purpose of this study was to evaluate and compare the evidence-based potential of answers provided by 4 LLMs to clinical questions in the field of implant dentistry.</p><p><strong>Material and methods: </strong>A total of 10 open-ended questions pertinent to prevention and treatment of peri-implant disease were posed to 4 distinct LLMs including ChatGPT 4.0, Google Gemini, Google Gemini Advanced, and Microsoft Copilot. The answers were evaluated independently by 2 periodontists against scientific evidence for comprehensiveness, scientific accuracy, clarity, and relevance. The LLMs responses received scores ranging from 0 (minimum) to 10 (maximum) points. To assess the intra-evaluator reliability, a re-evaluation of the LLM responses was performed after 2 weeks and Cronbach α and interclass correlation coefficient (ICC) was used (α=.05).</p><p><strong>Results: </strong>The scores assigned by the examiners on the 2 occasions were not statistically different and each LLM received an average score. Google Gemini Advanced ranked higher than the rest of the LLMs, while Google Gemini scored worst. The difference between Google Gemini Advanced and Google Gemini was statistically significantly different (P=.005).</p><p><strong>Conclusions: </strong>Dental professionals need to be cautious when using LLMs to access content related to peri-implant diseases. LLMs cannot currently replace dental professionals and caution should be exercised when used in patient care.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586043","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 reusing impression posts and scan bodies on recording accuracy.","authors":"Akin Aktas, Taha Yasar Manav, Mustafa Zortuk","doi":"10.1016/j.prosdent.2025.02.007","DOIUrl":"https://doi.org/10.1016/j.prosdent.2025.02.007","url":null,"abstract":"<p><strong>Statement of problem: </strong>The frequent reuse and sterilization of dental implant transfer components (ITCs) may cause deformation. Whether the reuse will compromise the accuracy of implant-supported restorations is unclear.</p><p><strong>Purpose: </strong>The purpose of this in vitro study was to evaluate the effects of repeated use and sterilization on the accuracy of ITCs and to determine the acceptable number of reuses before significant deformation occurs.</p><p><strong>Material and methods: </strong>Both conventional impression making and digital scanning were evaluated. The conventional groups were Group CS (Conventional Straumann), Group CD (Conventional Dio), and Group CM (Conventional Mode). For each group, 5 indirect impression copings were used on 3 different dental implants placed in casts. Impressions were repeated 10 times per coping, with sterilization at 134 °C for 10 minutes between each impression. The digital groups were analyzed by scanning casts with an intraoral scanner and scan bodies. The digital groups included Group DS (Digital Straumann), Group DD (Digital Dio), and Group DM (Digital Mode). Scans were repeated 10 times per scan body on a reference cast, with sterilization at 134 °C for 5 minutes between scans. Deviations between the casts were analyzed with a 3-dimensional software program. The root mean square (RMS) and deviation values according to implant brand, group, and impression or scanning order were compared with 3-way mixed ANOVA with repeated measures. A simple effect analysis with Bonferroni adjustment was performed for multiple comparisons (α=.05).</p><p><strong>Results: </strong>Repeated use and sterilization led to significant increases in deviations across all groups. In the conventional groups, RMS deviation for Group CS increased from 0.0304 to 0.0702 mm, for Group CD from 0.0522 to 0.1145 mm, and for Group CM from 0.0609 to 0.1047 mm over 10 impressions. For the digital groups, the RMS deviation for Group DS increased from 0.0149 to 0.0652 mm, for Group DD from 0.0134 to 0.0554, and for Group DM from 0.0203 to 0.0810 mm. All increases were statistically significant (P<.05).</p><p><strong>Conclusions: </strong>The repeated use and sterilization of ITCs led to significant deformation, reducing accuracy in both conventional impressions and digital scans. To maintain high accuracy, the reuse of ITCs should be limited based on the observed increase in deviations.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143586032","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":"A quantitative assessment of the influence of voltage on the formation of oxide layers on the surface of titanium by anodization.","authors":"Michał Wilk, Leszek Klimek, Beata Śmielak","doi":"10.1016/j.prosdent.2025.02.026","DOIUrl":"https://doi.org/10.1016/j.prosdent.2025.02.026","url":null,"abstract":"<p><strong>Statement of problem: </strong>Restorations based on titanium and its alloys form weak connections with veneering ceramics. It is unclear if anodizing the titanium surface with different voltages leads to improved bonding.</p><p><strong>Purpose: </strong>The purpose of this in vitro study was to obtain an oxide layer of an appropriate thickness (0.5 to 0.8 µm) and determine its bond strength.</p><p><strong>Material and methods: </strong>Titanium specimens were anodized in a mixture of 1 M H₂SO₄ and H₃PO₄ at 120 V, 160 V, and 200 V. The surface was examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), surface roughness testing, and contact angle to determine the surface free energy (SFE). The obtained results contact angle, and SPE were analyzed using the Friedman test, Dunn-Bonferroni post hoc test, and the Page trend test (α=.05). Statistically significant test value was P<.05 and highly significant P<.01. The adhesion of anodized layers to the surface of titanium specimens was determined according to the Verein Deutscher Ingenieure (VDI) 3198 norm (destructive quality test for coated compounds, Rockwell hardness).</p><p><strong>Results: </strong>In the diffraction diagram, the oxide layer has an anatase crystalline structure with thicknesses of 0.61 µm for 120 V, 1.25 µm for 160 V, and 2.30 µm for 200 V. The secondary electron (SE) and backscattered electron (BSE) images provide an indication of the topography and geometric structure pores, as well as their size and shape. Anodic coatings obtained with higher voltages demonstrate higher roughness profiles. The highest SFE value was obtained for 160 V anodization voltage, the smallest for 120 V. No significant differences in contact angles were observed (P>.05) between different voltages or between different electrolytes. No significant differences between voltages were observed for the dispersive component values (P>.05); however, significant differences were observed for polar components (P<.05). Higher values were noted for 160 V than for 120 V. All indentations were within the range indicated by models HF1 and HF2 (acceptable adhesion), which differ only in the density of the fractures.</p><p><strong>Conclusions: </strong>The voltage applied during anodic oxidation using a mixture of 1 M H₂SO₄ and H₃PO₄, influenced the thickness and structure of the obtained layers. The oxide obtained had a thickness of 0.6 to 2.3 µm and an anatase crystal structure.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143572968","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 of a 3D printed custom resin crossbar for complete arch implant scanning: An in vitro and in vivo study.","authors":"Qinyi Lu, Yujie Zhu, Yuan Chen, Peng Xu, Yuan Liang, Tao Chen","doi":"10.1016/j.prosdent.2025.02.023","DOIUrl":"https://doi.org/10.1016/j.prosdent.2025.02.023","url":null,"abstract":"<p><strong>Statement of problem: </strong>The accuracy of intraoral scanners for implant-supported prostheses in edentulous jaws is unclear with limited clinical evidence.</p><p><strong>Purpose: </strong>The purpose of this in vitro and in vivo study was to evaluate the accuracy of a novel 3-dimensionally (3D) printed custom resin scanning crossbar (3D-CRC) for digital scans of complete arch implants and to provide a clinical benchmark.</p><p><strong>Material and methods: </strong>Four implants were placed on a completely edentulous master model for in vitro scanning. Accuracy was compared among the conventional splinted open tray impression (CI) and 4 digital scanning groups: cylindrical scan bodies (DC), metal crossbars (DMC), digital wings (DW), and 3D-CRC (DRC). The digital group was scanned using the iTero Element 5D Plus (IT), Medit i500 (MD), and TRIOS 5 (TR) scanners, whereas the reference model was scanned using a laboratory scanner. The trueness, precision, linear and angular deviations, and efficiency were evaluated. A self-controlled in vivo study involving 12 participants compared CI and 3D-CRC-assisted digital scans. Root mean square (RMS), linear and angular deviations, and chairside time were evaluated. Aluminum frameworks were fabricated from the scan data and clinically tested for passive fit using the Sheffield test and radiographic examination. Data were analyzed with analysis of variance and paired t tests (α=.05).</p><p><strong>Results: </strong>No significant accuracy differences were found between TR and MD scanners (P>.05), both showed higher accuracy than IT (P≤.001). Trueness did not differ significantly between the DRC and CI groups. DRC outperformed the DC (P<.001) and DMC (P=.01) for IT, as well as the DW (P=.044) for MD. Precision was comparable between DRC and CI for IT and MD (P>.05). However, CI surpassed DRC (P=.012), DW (P<.001), DMC (P=.006), and DC (P<.001) for TR, whereas DRC outperformed DW, DMC, and DC (P<.001). Linear deviation analysis showed that DRC performed better than DW (P=.038), DMC (P=.001), and DC (P<.001) for MD and better than DMC and DC (P<.001) for IT. In vivo, aluminum frameworks demonstrated a good passive fit in clinical fit assessments, with an RMS of 43.3 ±19.1 µm.</p><p><strong>Conclusions: </strong>The 3D-CRC may improve the accuracy and operational efficiency of digital scans of edentulous arches, reducing linear and angular deviations compared with other scanning methods.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143572972","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":"Defining margins and emergence profile in vertical preparations: A digital technique.","authors":"Chiara Maria Morini, Leonardo Franchini, Carlo Massimo Saratti","doi":"10.1016/j.prosdent.2024.12.031","DOIUrl":"https://doi.org/10.1016/j.prosdent.2024.12.031","url":null,"abstract":"<p><p>The application of a digital workflow to the biologically oriented preparation technique (BOPT) is described. The BOPT places prosthesis margins apical to the free gingival margin, promoting natural gingival adaptation and long-term tissue stability. The digital method described here addresses the clinical challenges of impression making and the accurate replication of the emergence profile from the interim to the definitive restoration.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143567252","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 post-polymerization on stainability and surface roughness of 3D printed composite resin.","authors":"Samet Atasoy, Sultan Aktuğ Karademir, Serdar Akarsu, Yaşar Sert","doi":"10.1016/j.prosdent.2025.02.018","DOIUrl":"https://doi.org/10.1016/j.prosdent.2025.02.018","url":null,"abstract":"<p><strong>Statement of problem: </strong>Although the post-polymerization is a necessary step to attain the final properties and color of the 3-dimensionally (3D) printed composite resins, research on its effects on color change and surface roughness is lacking.</p><p><strong>Purpose: </strong>The purpose of this in vitro study was to evaluate the effect of post-polymerization time and additional placement in boiling water on the color change and surface roughness of 3D printed composite resins after exposure to coffee for 30 days.</p><p><strong>Material and methods: </strong>Sixty disk-shaped specimens (Ø10×2 mm) were 3D printed with composite resin (Crowntec). The specimens were randomly divided into 6 groups (n=10), according to the post-polymerization process at 3 different times (2×5, 2×10, and 2×20 minutes) and depending on subsequent placement in boiling water. The color differences (ΔE₀₀) between the baseline and each aging period (1, 7, 15, and 30 days) were determined by using a spectrophotometer. After 30-day aging period, ΔL*, Δa*, and Δb* values were calculated. The surface roughness (Ra) was measured at various aging periods (initial, 7, 15, and 30 days) by a 3D noncontact optical profilometer. The data were analyzed using 2-way repeated measures ANOVA and 1-way ANOVA tests for each aging period followed by Tukey tests (α=.05).</p><p><strong>Results: </strong>As the post-polymerization time increased, a significant decrease was found in ΔE₀₀ values (P<.001), while no significant difference was found in Ra values (P=.554). The values of ΔE₀₀ and Ra increased with the aging period (P<.001). Additional placement in boiling water resulted in a statistically significant decrease in both ΔE₀₀ and Ra values (P<.001). As the post-polymerization time increased, the Δa* and Δb* values decreased, while the negative ΔL* values increased (P<.001), except for Δa* between 2×10 and 2×20 (P=.175). Additional placement in boiling water resulted in a significant decrease in Δa* and Δb* values and an increase in the negative ΔL* values (P<.001), except for Δa* in 2×20 (P=.379).</p><p><strong>Conclusions: </strong>An increase in post-polymerization time resulted in reduced stainability, while additional placement in boiling water led to reduced stainability and roughness. When subsequently placed in boiling water, the post-polymerization time had no effect on either stainability or roughness.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143557272","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 artificial aging on color change and mechanical properties of high consistency maxillofacial silicone elastomers.","authors":"Nuran Ozyemisci, Meral Kurt, Secil Karakoca Nemli","doi":"10.1016/j.prosdent.2025.02.019","DOIUrl":"https://doi.org/10.1016/j.prosdent.2025.02.019","url":null,"abstract":"<p><strong>Statement of problem: </strong>Discoloration and the deterioration of mechanical properties lead to the replacement of maxillofacial prostheses. However, studies on the change in color and mechanical properties of high viscosity elastomers are lacking.</p><p><strong>Purpose: </strong>The purpose of this in vitro study was to evaluate the influence of artificial aging on the mechanical and optical properties of high-consistency silicone elastomer (HCR) and compare these properties with a widely used liquid silicone rubber (LSR).</p><p><strong>Material and methods: </strong>The specimens were fabricated from HCR (Derma-sil; Spectromatch Ltd.) and LSR (M511; Technovent Ltd.) silicone materials according to the manufacturers' instructions. A total of 325 specimens were used (50 for the tear test, 50 for the tensile and elongation test, 25 for the hardness test, 50 for absorption and solubility, and 50 for color and surface roughness measurements). Four subgroups of HCR with different Shore A hardness values (5, 20, 55, 70) were used. The specimens were subjected to tear (ASTM D624), tensile and elongation (ASTM D41215), hardness (ASTM D2240), absorption and solubility (ADA 12), surface roughness, and color change tests before and after the artificial aging process. Both water bath and ultraviolet (UV) chamber aging methods were used for the absorption and solubility tests. Contrast ratio and relative translucency parameters were also examined in addition to color change. Accelerated aging including UV light, humidity, and heat was carried out for 168 hours. The analyses were performed using 2-way factorial ANOVA and mixed ANOVA designs. Bonferroni multiple comparison test was used for significant results (α=.05).</p><p><strong>Results: </strong>The hardness values of all groups increased after aging except for the HCR subgroup with Shore A hardness 20 (P<.001). No significant change was found in surface roughness (P=.118), tear strength (P=.374), or elongation percentage (P=.053) after aging for all silicone groups. The only group with a significant change in tensile strength was HCR70 (P=.01). According to the water absorption results, absorption rates were significantly higher after artificial aging compared with bath aging in all silicone groups (P<.001) except LSR (P>.05). The aging method had significant effect on the water solubility of all groups (P<.001). Color change was significantly different among the silicone groups (P<.001).</p><p><strong>Conclusions: </strong>The HCR silicone elastomer tested in the study showed optical and mechanical properties compatible with those of a commonly used LSR silicone.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143557271","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}