Journal of Prosthetic Dentistry最新文献

{"title":"Impact of speed sintering on the mechanical and optical properties of multilayered zirconia.","authors":"Omar Mohamed, Hyeongil Kim, Steven Makowka, Ahmed AlMozayen, Kedith Sawangsri, Rui Li","doi":"10.1016/j.prosdent.2024.09.030","DOIUrl":"10.1016/j.prosdent.2024.09.030","url":null,"abstract":"<p><strong>Statement of problem: </strong>Speed sintering techniques have been introduced to shorten the sintering time of zirconia ceramics, yet their impact on multilayered zirconia properties remains understudied.</p><p><strong>Purpose: </strong>The purpose of this in vitro study was to assess the effect of speed sintering on the optical properties and the mechanical flexural strength of multilayered zirconia materials.</p><p><strong>Material and methods: </strong>A total of 360 disks (Ø14 ±2 mm ×1.2 ±0.02 mm) were fabricated by following the International Organization for Standardization (ISO) 6872:2015 standard using 2 types of Vita A2 shade multilayered zirconia materials: IPS e.max ZirCAD Prime (ZP) and IPS e.max ZirCAD Prime Esthetic (ZPE). Each material comprised translucent (Tr), gradient l (Gr), and dentin (De) layers, with 60 disks per layer. Half were sintered using a standard sintering protocol and half using a speed sintering protocol. Biaxial flexural strength was accessed using a universal testing machine equipped with the Blue Hill Universal software program by following the ISO 6872:2015 standard, with 20 disks per subgroup. The spectrophotometric analysis of optical properties (contrast ratio [CR], translucency parameter [TP], and total transmittance [Tt%]) was performed using a dual-beam spectrophotometer (Ultrascan VIS) in accordance with the ISO 7491:2000 standard, with 10 disks per subgroup. The comparison of the optical properties and the mechanical flexural strength between the speed and standard protocol was analyzed using an unpaired t test (α=.05).</p><p><strong>Results: </strong>Speed sintering reduced biaxial flexural strength in all ZP layers (P<.05) and in ZPE-Gr (P<.05). A statistically significant difference in the CR was observed in the ZP-Tr, ZP-Gr, and ZPE-Gr layers (P<.05). The TP of the ZP-Gr, ZP-De, and ZPE-Gr layers was significantly lower when using the speed sintering protocol. Tt% was significantly lower with speed sintering for both materials (P<.05).</p><p><strong>Conclusions: </strong>Speed sintering statistically changed both the optical (CR, TP, Tt%) and mechanical (flexural strength) properties of multilayered zirconia materials, but the differences may not be clinically relevant.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":"280.e1-280.e6"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142546092","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":"Number of consecutive procedures after endodontic treatment to extraction: A 28-year retrospective study.","authors":"Paz Kles, Hilit Bar-On, Asher Zabrovsky, Keren Kles, Sharon Eldad, Gilad Ben-Gal","doi":"10.1016/j.prosdent.2022.12.010","DOIUrl":"10.1016/j.prosdent.2022.12.010","url":null,"abstract":"<p><strong>Statement of problem: </strong>After endodontic treatment, teeth may require additional treatment. Data regarding the number of treatments up to extraction after endodontic treatment are lacking.</p><p><strong>Purpose: </strong>The purpose of this retrospective study was to evaluate the number of consecutive restorative procedures performed on a specific tooth starting from endodontic treatment up to extraction. A comparison was made between crowned and uncrowned teeth.</p><p><strong>Material and methods: </strong>A retrospective study was conducted using 28 years of data from a private clinic. The total number of patients was 18 082 and included 88 388 treated teeth. The data were collected for permanent teeth that received at least 2 consecutive retreatments. The data included tooth number, procedure type, date of procedure, total number of procedures conducted during the study period, extraction date, time from endodontic treatment to extraction, and whether the tooth had been crowned or not. Endodontically treated teeth were divided into 2 groups: extracted and nonextracted. In each group, a comparison was made between crowned and uncrowned teeth and between anterior and posterior teeth by using the Student t test (α=.05).</p><p><strong>Results: </strong>In the non extracted group, teeth that were crowned required significantly (P<.05) fewer restorative treatments (mean ±standard deviation 2.9 ±2.1) than uncrowned teeth (5.01 ±2.98). For extracted teeth, the mean time from endodontic treatment until extraction was 10.39 years. Crowned teeth were extracted after a mean of 11.06 years and 3.98 treatments, while uncrowned teeth were extracted after a mean of 9.96 years and 7.22 treatments (P<.05).</p><p><strong>Conclusions: </strong>Endodontically treated teeth that were crowned required significantly fewer subsequent restorative procedures than uncrowned teeth and exhibited higher survival rates up to extraction.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":"147-151"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9079563","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":"In vitro effect of anodization on surface roughness and bacterial adhesion to titanium abutments.","authors":"Shaghayegh Golalipour, Ezatollah Jalalian, Sara Koosha, Sotude Khorshidi, Maryam Torshabi, Maryam Sayyari","doi":"10.1016/j.prosdent.2024.08.004","DOIUrl":"10.1016/j.prosdent.2024.08.004","url":null,"abstract":"<p><strong>Statement of problem: </strong>Titanium abutments are considered the criterion standard for dental implants, yet the gray color poses esthetic concerns. Anodization has been proposed to enhance esthetics, but its effects on surface roughness and bacterial adhesion are unclear.</p><p><strong>Purpose: </strong>The purpose of this in vitro study was to assess the effect of anodization on surface roughness and bacterial adhesion to titanium abutments.</p><p><strong>Material and methods: </strong>Sixteen titanium abutments were divided into test (anodized) and control (nonanodized) groups (n=8). Anodization used 63 V from seven 9 V batteries and an electrolyte of 250 mL distilled water with 1 g trisodium phosphate. Surface roughness was measured with a profilometer at 4 mN force and 0.5 mm/second, assessing 3 supragingival points per specimen. In addition, 1 specimen from each group was selected for field-emission scanning electron microscopy (FE-SEM). Sterilized abutments were exposed to a Staphylococcus aureus suspension (10⁵ CFUs/mL) and then placed in phosphate-buffered saline (PBS), sonicated, vortexed, diluted, and cultured on agar. Bacterial adhesion was assessed after incubating 144 microplates at 37 °C for 24 hours. Colony counts were calculated using a dilution factor and serial dilution, and log 10 of CFUs/mL plotted. Data analysis used the Student t test for bacterial adhesion and the Mann-Whitney U test for surface roughness (α=.05).</p><p><strong>Results: </strong>The test and control groups showed no significant difference in surface roughness (P>.05). However, bacterial adhesion to anodized abutments was significantly lower than that to control abutments (P<.001).</p><p><strong>Conclusions: </strong>Anodization of titanium abutments significantly decreased bacterial adhesion and had no significant effect on surface roughness.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":"291.e1-291.e8"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142289767","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":"Elastic and fatigue properties of additively manufactured and milled Ti-6Al-4V removable partial denture clasps.","authors":"Minrui Xu, Yan Lin, Zhenxiang Lin, Hui Cheng","doi":"10.1016/j.prosdent.2024.09.017","DOIUrl":"10.1016/j.prosdent.2024.09.017","url":null,"abstract":"<p><strong>Statement of problem: </strong>The use of additive manufacturing Ti-6Al-4V (AM Ti64) in removable partial denture (RPD) frameworks has become increasingly prevalent in clinical practice. However, the elastic and fatigue properties of AM Ti64 clasps are not well understood.</p><p><strong>Purpose: </strong>The purpose of this in vitro study was to investigate the elastic and fatigue properties of AM Ti64 clasps by comparing them with milled Ti64 (Milled TC4) clasps.</p><p><strong>Material and methods: </strong>Dumbbell specimens of AM Ti64 and Milled TC4 were prepared for tensile tests following the International Organization for Standardization (ISO) 22674 standard (n=6). Raw (R) and mechanically polished (P) clasp-shaped specimens were prepared for elastic and fatigue tests and divided into 4 groups: AM Ti64R, AM Ti64P, Milled TC4R, and Milled TC4P. The clasp intaglio surface roughness was measured before testing (n=10). The elastic deformation limit (EDL) of the clasp was determined through incremental displacement loading (n=10). Fatigue tests were conducted on 160 clasps (40 specimens per group) at displacements from 0.30 mm to 1.00 mm for 10⁵ cycles (n=5 per displacement). The fracture surfaces of failed clasps were observed using a scanning electron microscope (SEM), and the microstructures were analyzed using optical microscopy. Statistical analyses were conducted using t tests and Kruskal-Wallis tests (α=.05).</p><p><strong>Results: </strong>AM Ti64 exhibited higher 0.2% offset yield strength and ultimate tensile strength than Milled TC4 (P<.001), with no significant difference in percentage elongation (P=.298) or elastic modulus (P=.151). No significant differences in intaglio surface roughness were found between AM Ti64 and Milled TC4 clasps in both the raw (P=.306) and polished (P>.999) groups. AM Ti64 clasps demonstrated greater EDL values than Milled TC4 clasps in both the raw and polished groups (P<.001). The fatigue life of AM Ti64 clasps was significantly shorter than that of Milled TC4 clasps (P<.001), with no significant difference between the raw and polished groups in both AM Ti64 (P=.611) and Milled TC4 clasps (P>.999). SEM observation revealed fatigue cracks originating from surface defects in AM Ti64 clasps. Microstructural analysis showed lamellar α phase dominance in AM Ti64, while Milled TC4 exhibited primarily equiaxed α phase.</p><p><strong>Conclusions: </strong>The AM Ti64 clasp showed better elasticity but inferior fatigue performance compared with Milled TC4 clasps. Mechanical polishing did not significantly affect the elasticity or fatigue properties of the titanium clasp.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":"230.e1-230.e8"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142468358","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":"Letter to the Editor regarding, \"Antimycotic prophylaxis with multispecies probiotics against oral candidiasis in new complete denture wearers: A randomized clinical trial\".","authors":"Wei-Zhen Tang, Xue-Bing Chen, Tai-Hang Liu","doi":"10.1016/j.prosdent.2024.09.018","DOIUrl":"10.1016/j.prosdent.2024.09.018","url":null,"abstract":"","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":"325-326"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142468361","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 machine learning in parafunctional and altered functional occlusion: A systematic review.","authors":"Taseef Hasan Farook, Farah Rashid, Saif Ahmed, James Dudley","doi":"10.1016/j.prosdent.2023.01.013","DOIUrl":"10.1016/j.prosdent.2023.01.013","url":null,"abstract":"<p><strong>Statement of problem: </strong>The advent of machine learning in the complex subject of occlusal rehabilitation warrants a thorough investigation into the techniques applied for successful clinical translation of computer automation. A systematic evaluation on the topic with subsequent discussion of the clinical variables involved is lacking.</p><p><strong>Purpose: </strong>The purpose of this study was to systematically critique the digital methods and techniques used to deploy automated diagnostic tools in the clinical evaluation of altered functional and parafunctional occlusion.</p><p><strong>Material and methods: </strong>Articles were screened by 2 reviewers in mid-2022 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible articles were critically appraised by using the Joanna Briggs Institute's Diagnostic Test Accuracy (JBI-DTA) protocol and Minimum Information for Clinical Artificial Intelligence Modeling (MI-CLAIM) checklist.</p><p><strong>Results: </strong>Sixteen articles were extracted. Variations in mandibular anatomic landmarks obtained via radiographs and photographs produced notable errors in prediction accuracy. While half of the studies adhered to robust methods of computer science, the lack of blinding to a reference standard and convenient exclusion of data in favor of accurate machine learning suggested that conventional diagnostic test methods were ineffective in regulating machine learning research in clinical occlusion. As preestablished baselines or criterion standards were lacking for model evaluation, a heavy reliance was placed on the validation provided by clinicians, often dental specialists, which was prone to subjective biases and largely governed by professional experience.</p><p><strong>Conclusions: </strong>Based on the findings and because of the numerous clinical variables and inconsistencies, the current literature on dental machine learning presented nondefinitive but promising results in diagnosing functional and parafunctional occlusal parameters.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":"124-128"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9315526","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":"Positional trueness of three removable die designs with different root geometries manufactured using stereolithographic 3D printing.","authors":"Francisco X Azpiazu-Flores, William M Johnston, Severino J Mata-Mata, Burak Yilmaz","doi":"10.1016/j.prosdent.2023.08.036","DOIUrl":"10.1016/j.prosdent.2023.08.036","url":null,"abstract":"<p><strong>Statement of problem: </strong>Three-dimensional (3D) printed casts are a suitable alternative to dental stone casts. Contemporary dental design computer programs permit designing definitive casts with removable dies with different root geometries and retention mechanisms. Studies on the positional trueness of 3D printed removable dies with different root geometries are lacking.</p><p><strong>Purpose: </strong>The purpose of this in vitro study was to investigate the 3D displacements of three 3D printed removable die designs with different root geometries.</p><p><strong>Material and methods: </strong>The digital file of a dental stone alveolar cast with root-form removable dies (MOD UJ IV Fixed Prosthetics; Ivoclar AG) was used as a reference to create 3 removable die and alveolar cast designs (Root Form, RF; Conical, CON; Cylindric, CYL) with different root geometries in 2 dental design computer programs (DentalCAD 3.1 Rijeka; exocad; GmbH; InLab CAD 22.0; Dentsply Sirona). 3 equidistant Ø1-mm spheres (C, Cervical; M, Middle; O, Occlusal) were designed on the buccal surface of the coronal portion of the removable die to evaluate their displacement. A total of 45 alveolar casts with 45 removable dies were fabricated using a stereolithographic 3D printer (Form 3; Formlabs); each die group consisted of 15 specimens. After fabrication and postprocessing, the specimens were scanned, and their digital files were analyzed in a metrology-grade computer program to evaluate the displacement of the removable dies with respect to the position of the die in the master reference file. Subsequently, the data were analyzed using a 3-way analysis of variance (ANOVA) followed by step-down Bonferroni-corrected pairwise comparisons (α=.05).</p><p><strong>Results: </strong>Two statistically significant 2-way interactions were detected between the independent variables, die design and direction (P<.001), and location and direction (P<.001). The post hoc analysis identified significant differences between the displacement values of RF and CYL (P<.001) and RF and the CON (P<.001) designs on the Y axis. The measured displacements were statistically different between the C and O locations on the Y axis (P=.001) and the M and O locations on the Z axis (P=.006).</p><p><strong>Conclusions: </strong>The root geometry of a 3D printed removable die and alveolar cast can affect seating, and variable degrees of tipping of the removable die can be seen. The seating and congruence of the removable die with the interocclusal space and relationships observed intraorally should be confirmed before adjusting indirect restorations.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":"178-183"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41128958","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":"Evaluation of the biomechanics of Aramany class I obturators of different designs using numerical and experimental methods. Part II: Stress distribution.","authors":"Mohammed A Mousa, Adam Husein, Mohamed I El-Anwar, Azirrawani Ariffin, Johari Yap Abdullah","doi":"10.1016/j.prosdent.2024.07.042","DOIUrl":"10.1016/j.prosdent.2024.07.042","url":null,"abstract":"<p><strong>Statement of problem: </strong>Evidence regarding stress evaluations of removable obturators with Aramany class I defects is lacking. Whether the stress distribution on Aramany class I prostheses can be improved by modifying the currently used designs is also unclear.</p><p><strong>Purpose: </strong>The purpose of part II of this study was to evaluate the stress distribution in different designs of Aramany class I obturators using finite element analysis (FEA) and photoelastic stress analysis.</p><p><strong>Material and methods: </strong>Four finite element and 8 photoelastic models, including 2 acrylic resin base obturators retained with 2 Adams clasps, 2 linear, 2 tripodal, and 2 fully tripodal design obturators, were used in this study. The frameworks were fabricated on the casts obtained from a modified printed model. Vertical and oblique loads were applied on 2 points (anterior and posterior) of the models. The quantitative measurement was done by measuring the fringe orders and von Mises values to compare the influences of occlusal forces on the obturator components and their supporting structures. The qualitative evaluation was done by visual color mapping to identify the stress concentration.</p><p><strong>Results: </strong>In the photoelastic analysis, the anterior abutments of the tripodal showed the highest stress, followed by the fully tripodal obturators, while, in FEA, the anterior abutments of the linear design received the most in both vertical and oblique load. The central incisor received the most stress in photoelastic (3 or more fringe orders) and FEA (687.3 and 150.1 MPa for vertical and oblique loads, respectively), followed by the lateral incisors. Upon posterior loading, the base of the defect of the linear design demonstrated the most stress in photoelastic (3 or more fringes) and FEA (94.3 and 130.5 MPa for vertical and oblique loads, respectively). The acrylic resin base obturator retained with Adams clasps demonstrated the lowest stress distribution in abutments and their supporting bone upon anterior and posterior loads.</p><p><strong>Conclusions: </strong>Upon vertical and oblique load application, the fully tripodal design was comparable with the tripodal in terms of stress distribution. Both designs were better than the linear in response to the same loading. The stress was concentrated at the anterior palatal part of the obturator, the base of the defect, and the junction of the metal and acrylic resin part of the prostheses upon anterior and posterior loading, respectively.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":"321.e1-321.e8"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142126045","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 low-temperature degradation treatment on hardness, color, and translucency of single layers of multilayered zirconia.","authors":"Mi-Gyoung Park","doi":"10.1016/j.prosdent.2023.01.023","DOIUrl":"10.1016/j.prosdent.2023.01.023","url":null,"abstract":"<p><strong>Statement of problem: </strong>Evaluating the effect of low-temperature degradation (LTD) on multilayered zirconia blocks is important for the long-term life of zirconia restorations.</p><p><strong>Purpose: </strong>The purpose of this in vitro study was to analyze the changes in color, translucency, and hardness of a single layer of multilayered zirconia after an LTD treatment.</p><p><strong>Material and methods: </strong>Ninety multilayered 10×10×1.0-mm zirconia specimens (3M Lava Esthetic) were designed using Auto CAD 2006 (Autodesk) and divided into 6 groups (n=15) based on LTD (no treatment, LTD treatment) and the inherent layer type (incisal, transition, and body). The hardness of each specimen was measured using a microVickers hardness tester. The CIELab color coordinates were measured using a spectrophotometer, and the data were used to calculate the color difference and translucency (TP). Data were analyzed using 2-way ANOVA and the Scheffé test (α=.05).</p><p><strong>Results: </strong>LTD treatment did not alter the hardness of multilayered zirconia (P=.572). A significant difference was found in the hardness between the layers of multilayered zirconia (P<.001). LTD treatment did not alter the b∗ or L∗ values (P=.773, P=.701) but did change the a∗ values (P<.001). On LTD treatment, the a∗ value was found to decrease. The L∗, a∗, and b∗ values differed based on the respective layer within the material (P<.001). As layers progress from the incisal to the body, the L∗ value decreased and the a∗ and b∗ values increased. In all groups, the color difference values were highest in the following order: the incisal and transition layers < the transition and body layers < the incisal and body layers. On LTD treatment, the color difference between the layers decreased. The LTD treatment did not affect the TP value (P=.208), but the TP value for each layer showed a significant difference (P<.001).</p><p><strong>Conclusions: </strong>LTD treatment did not affect the optical properties or hardness of the multilayered zirconia. The hardness of the multilayered zirconia increased from the incisal to the body layer. In multilayered zirconia, the brightness decreased from the incisal to the body layer, and red and yellow color changes were observed. The TP of multilayered zirconia increased from the incisal to the body layer.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":"258-263"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10809542","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":"Retrieval of a fractured implant abutment using a modified cover screw removal instrument: A clinical report.","authors":"Wen-Tao Zhang, Yu-de Ding, Lin-Hong Wang, Fan Yang","doi":"10.1016/j.prosdent.2023.07.038","DOIUrl":"10.1016/j.prosdent.2023.07.038","url":null,"abstract":"<p><p>Implant abutment fractures are an uncommon mechanical complication, and the removal of the abutment fragment and replacement with a new prosthesis is the best solution. However, successful retrieval of the fractured abutment fragment from the implant is challenging, and effective rescue kits are lacking. This clinical report describes the retrieval of a fractured implant abutment in a conical connection implant using a modified manufacturer-specific instrument.</p>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":" ","pages":"14-17"},"PeriodicalIF":4.3,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10651928","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}