Journal of Prosthetic Dentistry最新文献

{"title":"Combined digital–conventional workflow to fabricate a definitive obturator from an interim obturator for a patient with an anterior maxillectomy defect","authors":"Islam E. Ali BDS, MDS ,&nbsp;Kouichi Enomoto CDT ,&nbsp;Yuka Sumita DDS, PhD ,&nbsp;Noriyuki Wakabayashi DDS, PhD","doi":"10.1016/j.prosdent.2023.04.028","DOIUrl":"10.1016/j.prosdent.2023.04.028","url":null,"abstract":"<div><div>An existing interim obturator can be reproduced as the definitive one using digital technology, with benefits for a patient with a maxillectomy. By digitally scanning the oral condition and the existing interim obturator, a definitive obturator, including a computer-aided designed and computer-aided manufactured metal framework, was fabricated and delivered to a patient with an anterior maxillectomy defect by following a combined digital and conventional workflow. This technique can hasten the adaptation of the patient to the new obturator and ensure a more comfortable and safer clinical procedure.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"133 3","pages":"Pages 920-925"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9579399","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 cement space settings on the marginal and internal fit of 3D printed definitive resin crowns","authors":"Heedo Shin DDS ,&nbsp;You-Jung Kang PhD ,&nbsp;Hoon Kim PhD ,&nbsp;Jee-Hwan Kim DDS, MSD, PhD","doi":"10.1016/j.prosdent.2023.03.021","DOIUrl":"10.1016/j.prosdent.2023.03.021","url":null,"abstract":"<div><h3>Statement of problem</h3><div>The cement gap setting affects the marginal and internal fits depending on the crown material and manufacturing method (subtractive or additive manufacturing). However, information on the effects of cement space settings in the computer-aided design (CAD) software program, which is used to aid the manufacturing with 3-dimensional (3D) printing-type resin material, is lacking, and recommendations for optimal marginal and internal fit are needed.</div></div><div><h3>Purpose</h3><div>The purpose of this in vitro study was to evaluate how cement gap settings affect the marginal and internal fit of a 3D printed definitive resin crown.</div></div><div><h3>Material and methods</h3><div>After scanning a prepared typodont left maxillary first molar<span>, a crown was designed with cement spaces of 35, 50, 70, and 100 μm by using a CAD software program. A total of 14 specimens per group were 3D printed from definitive 3D printing resin. By using the replica technique, the intaglio surface of the crown was duplicated, and the duplicated specimen was sectioned in the buccolingual and mesiodistal directions. Statistical analyses were performed using the Kruskal–Wallis and the Mann–Whitney post hoc tests (α=.05).</span></div></div><div><h3>Results</h3><div>Although the median values of the marginal gaps were within the clinically acceptable limit (&lt;120 μm) for all the groups, the smallest marginal gaps were obtained with the 70-μm setting. For the axial gaps, there was no observed difference in the 35-, 50-, and 70-μm groups, and the 100-μm group showed the largest gap. The smallest axio-occlusal and occlusal gaps were obtained with the 70-μm setting.</div></div><div><h3>Conclusions</h3><div>Based on the findings of this in vitro study, a 70-μm cement gap setting is recommended for optimal marginal and internal fit of 3D printed resin crowns.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"133 3","pages":"Pages 821-826"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9841660","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":"Wear resistance of 3D printed, milled, and prefabricated methacrylate-based resin materials: An in vitro study","authors":"Passupang Veerapeindee DDS ,&nbsp;Pimduen Rungsiyakull DDS, MDSc, PhD, FRCDS ,&nbsp;Wissanee Jia-mahasap DDS, MS, FACP","doi":"10.1016/j.prosdent.2024.12.006","DOIUrl":"10.1016/j.prosdent.2024.12.006","url":null,"abstract":"<div><h3>Statement of problem</h3><div>Three-dimensional (3D) printing and milling technologies have been increasingly used in prosthodontic practice for fabricating digital prostheses. Nevertheless, evidence relating to the wear resistance of denture teeth fabricated using these methods is lacking.</div></div><div><h3>Purpose</h3><div>The purpose of this in vitro study was to compare the wear resistance exhibited by denture teeth fabricated using 3D printing and milling technologies with prefabricated denture teeth.</div></div><div><h3>Material and methods</h3><div>Fifty specimens of resin denture teeth from 3 types of manufacturing processes were prepared and divided into 5 groups: 1 group of 3D printed denture teeth (NextDent C&amp;B MFH), 2 groups of milled denture teeth (Ivotion Dent and VIPI Block), and 2 groups of prefabricated denture teeth (Major Dent and Cosmo HXL). Each group of specimens was occluded with a zirconia antagonist under a 49-N load with thermocycling conditions for 120 000 cycles. The antagonist was horizontally displaced back and forth at a 2-mm distance and a frequency of 1.6 Hz. The quantification of the volume loss and the maximal wear depth of the worn specimens were recorded, while the wear characteristics were assessed with a scanning electron microscope (SEM). Data were analyzed using the Kruskal-Wallis test followed by pairwise comparison tests (α=.05).</div></div><div><h3>Results</h3><div>Significantly different wear depths and volume losses were found among groups (<em>P</em>&lt;.05). The highest wear depth and volume loss were observed in the VIPI Block (0.513 ±0.147 mm and 3.094 ±0.790 mm³), followed by Cosmo HXL group (0.312 ±0.020 mm and 1.446 ±0.134 mm³), Major Dent (0.261 ±0.034 mm and 1.219 ±0.196 mm³), Ivotion Dent (0.253 ±0.021 mm and 1.082 ±0.089 mm³), and NextDent C&amp;B MFH (0.208 ±0.059 mm and 0.843 ±0.372 mm³). Based on the analysis of the SEM images, distinct groups of specimens exhibited varying degrees of crack formation. Furthermore, their worn surfaces showed diverse characteristics in terms of wear patterns and roughness attributes.</div></div><div><h3>Conclusions</h3><div>The manufacturing methods for fabricating 3D printed, milled, and prefabricated denture teeth exhibit comparable wear resistance, with 3D printed denture teeth demonstrating the highest level of wear resistance.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"133 3","pages":"Pages 904.e1-904.e8"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142872402","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":"Sponsoring Organizations and Liaisons","authors":"","doi":"10.1016/S0022-3913(25)00164-7","DOIUrl":"10.1016/S0022-3913(25)00164-7","url":null,"abstract":"","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"133 3","pages":"Page A2"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593167","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":"Assessment of mechanical properties and microstructure of Co-Cr dental alloys manufactured by casting, milling, and 3D printing","authors":"Ana Schettini DMD ,&nbsp;Igor J. Pesun DMD, MS ,&nbsp;Rodrigo França DMD, MS, PhD","doi":"10.1016/j.prosdent.2024.12.017","DOIUrl":"10.1016/j.prosdent.2024.12.017","url":null,"abstract":"<div><h3>Statement of problem</h3><div>The mechanical properties and microstructure of cobalt chromium (Co-Cr) alloys should be considered when choosing the best alloy for each clinical situation. More information is needed on the digital manufacturing methods of metals in dentistry, such as computer numerical control (CNC), and direct laser metal sintering (DMLS).</div></div><div><h3>Purpose</h3><div>The aim of this study was to investigate the effect of the 3 different Co-Cr manufacturing processes on the mechanical properties and microstructure of Co-Cr dental alloys.</div></div><div><h3>Material and methods</h3><div>Dumbbell-shaped specimens (n=6) were fabricated using casting (CAST), CNC, and DMLS techniques. Tensile, 3-point bend, and microhardness testing were performed, and the microstructure evaluated through scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction analysis. The ANOVA test followed by post hoc Tukey tests were used for statistical analysis (α=.05).</div></div><div><h3>Results</h3><div>DMLS showed the greatest values for 0.2% yield strength (908.0 ±13.1 MPa), tensile strength (1123.7 ±6.5 MPa), flexural strength (2273.0 ±43.2 MPa), and microhardness (438.2 ±44.9 HV), followed by CAST and CNC. No statistical differences were found for elongation between CNC and DMLS or DMLS and CAST (<em>P</em>&gt;.05). No statistical differences were found in elastic modulus among all groups (<em>P</em>&gt;.05). EDX revealed a slightly different chemical composition among the groups. XRD showed face-centered cubic as the dominant phase and a small amount of hexagonal close-packed structure in all groups. A peak of σ phase was identified in the CAST group.</div></div><div><h3>Conclusions</h3><div>The mechanical properties and microstructures of Co-Cr dental alloys were significantly influenced by the fabrication method used. DMLS and CNC milling produced better products that traditional methods, leading to the improved durability and reliability of dental prostheses. These advancements underscore the importance of selecting appropriate fabrication methods to optimize clinical outcomes and patient satisfaction.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"133 3","pages":"Pages 906.e1-906.e7"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142909811","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":"Assessment of the internal connection of an angled screw channel system","authors":"Seoyoun Hahn DDS, MSD ,&nbsp;Van Ramos Jr DDS ,&nbsp;Jonathan An DDS, PhD ,&nbsp;Chandur P.K. Wadhwani BDS, MSD ,&nbsp;Jeffrey E. Rubenstein DMD, MS ,&nbsp;Alan Sutton DDS, MS ,&nbsp;Kwok-Hung Chung DDS, MS, PhD","doi":"10.1016/j.prosdent.2024.12.019","DOIUrl":"10.1016/j.prosdent.2024.12.019","url":null,"abstract":"<div><h3>Statement of problem</h3><div>The angled screw channel (ASC) design has been well accepted for implant prostheses. However, investigation into the behavior of the ASC connection is sparse.</div></div><div><h3>Purpose</h3><div>The purpose of this in vitro study was to assess the effect of cyclic loading on the internal connection of an ASC system compared with straight access systems by measuring reverse torque values (RTVs) and using microcomputed tomography (µCT) imaging.</div></div><div><h3>Material and methods</h3><div>Thirty dental implants (SLActive; Institut Straumann AG) were embedded in autopolymerizing acrylic resin and divided into 3 groups: Group V0, prefabricated abutment with a straight access channel; Group V25, prefabricated abutment with a 25-degree access channel; and Group C, cemented custom abutment with straight access. All specimens were initially secured with 10 Ncm using a digital torque gauge. A subset of specimens from each group (n=4) were randomly selected and assigned for µCT imaging examination and then reimaged after tightening to 35 Ncm. All specimens were subjected to cyclic loading for 5000 cycles with a loading force of 155 ±5 N at 1.2 Hz frequency in a 37 °C water bath using a fatigue machine. Repeat µCT imaging was done after cyclic loading for the representative specimens. The changes to the internal connection were measured on µCT images using a software program, and the RTV measurement of each specimen after cyclic loading treatment was recorded. The ANOVA test was used to analyze the statistical significance of the RTVs among groups (α=.05). The paired <em>t</em> test was used to conduct within-group comparisons of the measurement data.</div></div><div><h3>Results</h3><div>Mean ±standard deviation of RTVs varied from 29.05 ±2.99 Ncm to 29.75 ±2.61 Ncm, with no statistically significant differences among the 3 groups (<em>P</em>=.820). The distances from the base of the screw head to the apex of the screw-abutment-implant (SAI) system and internal air space volume within the groups V0 and V25 decreased significantly (<em>P</em>&lt;.05) between the 10-Ncm and 35-Ncm torque applications. Off-axis loading resulted in rotational movement of the abutment that might have created a tensional force on the implant screw.</div></div><div><h3>Conclusions</h3><div>Results for the prefabricated abutment groups (V0, V25) indicated that the RTVs were not affected by the amount of angle correction. A counterclockwise rotational movement of the abutment and screw within the SAI system would be formed during off-axial loading.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"133 3","pages":"Pages 844.e1-844.e9"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142909813","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":"Digitally designed and milled implant-retained maxillofacial prosthesis for velopharyngeal closure in a patient with a nonsurgically treated cleft palate: A clinical report","authors":"Ji-Hyun Park DDS, MSD ,&nbsp;In-Sung Luke Yeo DDS, MSD, PhD","doi":"10.1016/j.prosdent.2024.06.007","DOIUrl":"10.1016/j.prosdent.2024.06.007","url":null,"abstract":"<div><div>An implant-retained maxillofacial overdenture with a pharyngeal speech aid prosthesis was fabricated for a patient with a nonsurgically treated cleft palate who was unable to achieve velopharyngeal closure. Computer-aided design and computer-aided manufacturing were used to fabricate a metal-reinforced prosthesis using the Ivotion Denture System and subtractive manufacturing with geographic guides. Magnetic attachments were incorporated to improve the retention and stability of the prosthesis. Masticatory function, deglutition, and esthetics were found to be improved at the 6-month follow-up.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"133 3","pages":"Pages 908-914"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141590588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analyses of time efficiency and cost in fabricating fixed implant-supported prostheses in digital, hybrid, and conventional workflows: A systematic review and meta-analysis","authors":"Marion Bessadet DDS, MSc, PhD ,&nbsp;Chantal Auduc DDS, MSc ,&nbsp;Noémie Drancourt DDS, MSc ,&nbsp;Emmanuel Nicolas DDS, MSc, PhD, HDR ,&nbsp;Nada El Osta DDS, MSc, PhD, HDR","doi":"10.1016/j.prosdent.2024.06.024","DOIUrl":"10.1016/j.prosdent.2024.06.024","url":null,"abstract":"<div><h3>Statement of problem</h3><div>Economic considerations affect whether new technologies are adopted in dental practice. Limited evidence exists regarding the time and cost efficiency of different workflows for fabricating implant-supported restorations.</div></div><div><h3>Purpose</h3><div>The purpose of this systematic review and meta-analysis was to compare the time and cost involved in fabricating fixed implant-supported prostheses using digital, hybrid, and conventional methods throughout the entire prosthetic treatment by analyzing both clinical and laboratory steps.</div></div><div><h3>Material and methods</h3><div>A systematic review was conducted following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA)-P 2015 guidelines. The methods and inclusion criteria were specified in a protocol registered with the International Prospective Register of Systematic Reviews (PROSPERO) (registration number CRD42023458734). The databases PubMed, Cochrane, and PROSPERO were searched using keywords: (Prosthodontic OR restorative dentistry OR denture) AND (CAD CAM OR Digital workflow OR Computer Dentistry OR Digital Design) AND (Economic OR cost OR Financial OR time efficiency). Two investigators selected articles independently.</div></div><div><h3>Results</h3><div>A qualitative synthesis of 12 articles published from 2010 to 2023 showed that digital scans took less time than conventional impressions (<em>P</em>&lt;.05) in 7 out of 9 articles. Additionally, 8 articles revealed significant reductions in laboratory working time with digital workflows, intermediate times with hybrid workflows, and longer times with conventional workflows (<em>P</em>&lt;.001). Meta-analysis confirmed the time efficiency of digital scanning over conventional impressions (Hedges g=1.65, 95% CI [0.33, 2.98]) and a substantial reduction in laboratory time with digital workflows compared with other workflows (Hedges g=6.55, 95% CI [2.69; 10.42]). However, no significant difference was found in adjustment time between digital and other workflows (Hedges g=0.91, 95% CI [−0.72; 2.55]). Direct laboratory costs were observed to be higher in conventional workflows compared with hybrid or digital workflows, with hybrid workflows also showing elevated costs compared with digital workflows (<em>P</em>&lt;.05).</div></div><div><h3>Conclusions</h3><div>The digital workflow demonstrates potential benefits in reducing scan time, laboratory processing time, and direct laboratory costs for implant-supported restorations in partial edentulism. Further research is needed to validate these findings, particularly for long-span implant-supported fixed partial prostheses.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"133 3","pages":"Pages 689-712"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141788382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Letter to the Editor regarding, “An up to thirty-year retrospective study on the success and survival of single unit and splinted implant-supported crowns in a dental school setting”","authors":"Pitchaipillai Sankar Ganesh PhD,&nbsp;Naji Naseef Pathoor MSc,&nbsp;Rajesh Kanna Gopal PhD","doi":"10.1016/j.prosdent.2024.10.040","DOIUrl":"10.1016/j.prosdent.2024.10.040","url":null,"abstract":"","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"133 3","pages":"Pages 938-939"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142750749","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":"Residual dentin thickness and biomechanical performance of post-and-core-restored mandibular premolars: A finite element analysis study","authors":"Yi Sun BDS ,&nbsp;Ze-feng Wang MSD ,&nbsp;Yue-dan Xu DDS ,&nbsp;Ling Zhang DDS","doi":"10.1016/j.prosdent.2024.11.014","DOIUrl":"10.1016/j.prosdent.2024.11.014","url":null,"abstract":"&lt;div&gt;&lt;h3&gt;Statement of problem&lt;/h3&gt;&lt;div&gt;Endodontically treated teeth often require post-and-core restorations for structural support because of extensive hard tissue loss. Assessment of the effect of the residual dentin thickness on the biomechanical performance of these restorations is lacking.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Purpose&lt;/h3&gt;&lt;div&gt;The purpose of this study was to evaluate the residual dentin thickness in mandibular premolars after post-and-core restorations using cone beam computed tomography (CBCT) and to analyze the stress distribution with finite element analysis (FEA).&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Material and methods&lt;/h3&gt;&lt;div&gt;The CBCT data from 236 mandibular premolars having undergone post-and-core restorations were examined. An imaging software program (NNT; NewTom) was used to measure the buccolingual and mesiodistal root diameters in cross-sections 5 to 11 mm from the radiologic apex. The CBCT derived measurements were subsequently integrated into an FEA model. A 3-dimensional (3D) mandibular premolar model reflecting the residual dentin thickness was created with a computer-aided design software program (Hypermesh 9.0; Altair Engineering). A static force of 100 N was applied directly to the buccal cusp tip at 45, 60, 75, and 90 degrees to the long axis of the tooth, and the stress distribution of dentin was analyzed by using an FEA software program (ANSYS APDL 18.0; Ansys Inc).&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Results&lt;/h3&gt;&lt;div&gt;CBCT analysis showed that the buccolingual root diameter was wider than the mesiodistal diameter and that the residual dentin thickness of the buccal aspect was approximately 0.3 mm thinner compared with the lingual aspect along the root. The proportions of residual dentin thickness values in the buccolingual direction of the mandibular premolar teeth no less than 1 mm exceeded 96.2% at 5 to 11 mm from the apex. The proportions of residual dentin thickness values in the mesiodistal direction of the mandibular premolar teeth &gt;1 mm were 92.1% and 88.2% at 11 mm from the apex after post space preparation and decreased further to 70.8% and 58.9% at 5 mm from the apex. The von Mises stresses of the mandibular premolar model with residual dentin thickness were mainly localized to the cervical area (region C, cervix) and the post apex (region A, apex) in the buccolingual direction. Tensile and compressive stress were concentrated on regions C and A on the buccal and lingual sides, respectively. The actual residual dentin thickness model demonstrated higher maximum tensile stress compared with the 1-mm residual dentin thickness model under various loading conditions.&lt;/div&gt;&lt;/div&gt;&lt;div&gt;&lt;h3&gt;Conclusions&lt;/h3&gt;&lt;div&gt;During the process of post space preparation in mandibular premolars, sufficient dentin thickness should be retained in the apical region. The tensile stresses of mandibular premolars after clinical post-and-core restoration were mainly concentrated in the cervical area and the post apex, and the maximum tensile stress value was higher t","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"133 3","pages":"Pages 820.e1-820.e8"},"PeriodicalIF":4.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142895523","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}