The International journal of prosthodontics最新文献

{"title":"A Pilot Study to Predict Lifetime of Resin-Based Materials for Denture: Presentation of an In Vitro Thermally-Accelerated Ageing Method.","authors":"Lionel Sadoun, Guy Ravalec, Géraldine Rohman, Claudine Wulfman","doi":"10.11607/ijp.8854","DOIUrl":"https://doi.org/10.11607/ijp.8854","url":null,"abstract":"<p><strong>Purpose: </strong>The aim of this article was to present a method for predicting dental materials lifetime, using in vitro thermally accelerated ageing. The technique was tested to compare the behavior of 3 resin base materials for denture.</p><p><strong>Materials and methods: </strong>Bar-shaped samples of the poly(methyl methacrylate) PMMA based-resin Probase Hot (Probase), CAD/CAM disc Ivobase CAD (IvoCAD) and high-impact resin IvoCAP were aged in artificial saliva for 15, 30, 45, 60, 90, 120 and 180 days at 55°C, 75°C and 90°C. Flexural strength and surface roughness of the 3 resins for each ageing duration and temperature were measured for 3 samples (n=189). Using the time-temperature equivalence principle and the Arrhenius model, a master curve was constructed, the activation energy of the simulated ageing process was calculated and the lifetime of each material was estimated, based on degradation of flexural strength value over time.</p><p><strong>Results: </strong>The mean initial flexural strength was 87.98 ± 7.37, 79.35 ± 10.01 and 97.31 ± 4.97 MPa for IvoCAD, IvoCAP and Probase, respectively. Activation energies of the ageing in artificial saliva were measured at 81.9, 82.6 and 66.2 kJ/mol, respectively, and average lifetimes at 37°C were estimated at 19.5, 14.4 and 9.2 years.</p><p><strong>Conclusion: </strong>In this first approach to estimating the in vitro lifetime in artificial saliva of resin-based materials for dentures, the three materials met the expected criteria, validating the estimation method. Therefore, thermally-accelerated ageing and the Arrhenius model could be an interesting tool to add to routine tests used to validate new polymer materials and manufacturing processes.</p>","PeriodicalId":94232,"journal":{"name":"The International journal of prosthodontics","volume":"0 0","pages":"1-19"},"PeriodicalIF":0.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142866877","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Vitro Comparison of Surface Characteristics and Bacterial Adhesion in Composite Resin-Based Materials for Additive, Subtractive, and Conventional Manufacturing.","authors":"Sevde Gül Batmaz, Zehra Süsgün Yildirim, Zeynep Ceren Çelik, Dilajla Ardiç, Cihan Küden","doi":"10.11607/ijp.9212","DOIUrl":"https://doi.org/10.11607/ijp.9212","url":null,"abstract":"<p><strong>Purpose: </strong>This study aims to compare the surface roughness (SR), contact angle (CA), surface free energy (SFE), and bacterial adhesion of resin-based materials used in additive, subtractive, and conventional manufacturing techniques.</p><p><strong>Materials and methods: </strong>This study involved four groups of 23 specimens: Indirect conventional resin composite (ICRC), subtractively manufactured resin composite (SMRC), additively manufactured resin composite (AMRC), and soda-lime-silica glass (SLSG). One specimen per group was analyzed by Energy Dispersive X-ray Spectroscopy (EDS) before polishing. Following the polishing procedure, SR, CA, and SFE were measured. The sterilized specimens were divided into two subgroups for Streptococcus mutans and Streptococcus mitis adhesion. One randomly selected specimen from each group was also reserved for visualization of bacterial adhesion using Scanning Electron Microscopy (SEM), and bacterial adhesion was quantified in the remaining specimens (n=10). Data for SR, CA, SFE, and bacterial adhesion were analyzed using one-way ANOVA, Tukey post-hoc tests, and Pearson correlation (α = .05).</p><p><strong>Results: </strong>Among the resin groups, the ICRC group had the lowest SR values (P < .001). The higher CA was observed in the SMRC group than AMRC (P = .016). AMRC displayed significantly lower S. mitis adhesion compared to ICRC and SMRC (P < .001 and P = .003, respectively). A positive correlation was found between SR and S.mutans adhesion (R = .455, P < .003).</p><p><strong>Conclusion: </strong>Resin materials designed for different manufacturing techniques exhibited diverse surface characteristics. Nevertheless, the 3D printable permanent resin demonstrated comparable S. mutans adhesion to that of ICRC and SMRC.</p>","PeriodicalId":94232,"journal":{"name":"The International journal of prosthodontics","volume":"0 0","pages":"1-31"},"PeriodicalIF":0.0,"publicationDate":"2024-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142866898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Fiber Reinforcement on the Flexural Strength of Long-Span, 3D-Printed, Interim Fixed Dental Prosthesis.","authors":"Suphansa Sivakorn, Richard Lin, Cheryl Park","doi":"10.11607/ijp.9203","DOIUrl":"10.11607/ijp.9203","url":null,"abstract":"<p><strong>Purpose: </strong>To inspect the impact of polyethylene fiber (Ribbond) on the long-span, 3D-printed, interim fixed dental prosthesis regarding fracture strength.</p><p><strong>Materials and methods: </strong>A stainless steel platform was fabricated to replicate the partial edentulism for a maxillary four-unit fixed dental prosthesis. The prosthesis was fabricated by a Formlabs SLA 3D printer. The specimens were allocated into four groups of 20 each: experimental reinforced Group A (prosthesis with a slot reinforced with fiber); experimental Group B (prosthesis with a slot filled with 3D-printed material), negative control Group C (prosthesis with a slot); and control Group D (full-contour prosthesis). Fracture strength exams were performed with a universal tester. The fracture patterns were examined. A statistical analysis was conducted using one-way ANOVA and Tukey HSD test.</p><p><strong>Results: </strong>The control group exhibited a significantly higher mean flexural load (D: 306.32 ± 50.76 N) compared to the other groups (A: 194.37 ± 68.02 N; B: 178.25 ± 42.67 N; and C: 156.68 ± 29.73 N; [P < .001]). No differences were identified among Groups A, B, and C. The fracture pattern differed between the nonreinforced Groups B, C, and D and reinforced Group A, with catastrophic failure observed in the nonreinforced group and unseparated failure observed in the reinforced group.</p><p><strong>Conclusions: </strong>The study findings demonstrate that the incorporation of Ribbond in 3D-printed, interim fixed dental prostheses does not significantly enhance their fracture strength. However, it does lead to a noticeable change in the fracture behavior, shifting from a complete failure to an incomplete fracture pattern.</p>","PeriodicalId":94232,"journal":{"name":"The International journal of prosthodontics","volume":"0 0","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142804128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Digital Protocol for Management of the Restorative Margin and Emergence Profile of Vertically Prepared Teeth.","authors":"Panagiotis Ntovas, George Loubrinis, Nitzan Bichacho, Efstratios Papazoglou","doi":"10.11607/ijp.8599","DOIUrl":"10.11607/ijp.8599","url":null,"abstract":"<p><strong>Purpose: </strong>To describe a digital workflow for the management of the emergence profile and the restoration's finishing line on vertically prepared teeth using a digital data set.</p><p><strong>Materials and methods: </strong>Three scans (the prepared teeth the day of the preparation, the provisional restoration placed on the preparation after soft tissue maturation, and the provisional restoration outside of the oral cavity) were combined under a common data set to provide the necessary information to design the final restoration.</p><p><strong>Results: </strong>The digital technique presented can facilitate the implementation of the vertical preparation, because the desired finish line can be defined by the clinician and be transferred predictably to the dental lab. The current approach provides an alternative gingival management method, taking advantage of the displacement of soft tissue after vertical preparation.</p><p><strong>Conclusions: </strong>Positioning of the final finishing line on vertically prepared teeth, management of soft tissue, and fabrication of the final restoration can be facilitated with this approach, combining a digital data set that has been obtained during a distinct phase of the treatment.</p>","PeriodicalId":94232,"journal":{"name":"The International journal of prosthodontics","volume":"0 0","pages":"711-715"},"PeriodicalIF":0.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138292633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"INVESTIGATION OF MICROSCOPIC STRUCTURE, TRANSLUCENCY PARAMETERS, AND FRACTURE TOUGHNESS OF TWO PRESSABLE LITHIUM DISILICATE GLASS-CERAMIC MATERIALS.","authors":"Piya-Orn Suttipongkiat, Montri Ratanajanchai, Kallaya Suputtamongkol","doi":"10.11607/ijp.8720","DOIUrl":"10.11607/ijp.8720","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the microscopic structure and fracture toughness of two pressable glass-ceramics-GC Initial LiSi Press (LiSi) and IPS e.max Press (e.max)-with different levels of translucency.</p><p><strong>Materials and methods: </strong>Two groups each of LiSi and e.max, with medium opacity and high translucency levels, were examined. The crystal morphology of acid-etched specimens was observed under a scanning electron microscope (SEM). Six specimens in each group were fabricated in a square shape (12 ' 12 ' 1.5 mm) to measure translucency parameters (TP) using a spectrophotometer. Ten bar-shaped specimens in each group with dimensions of 23 x 2 x 4 mm were used to determine the fracture toughness (KIc) by a surface crack in flexure (SCF) using a universal testing machine. One-way ANOVA and Scheffe post-hoc tests were used for statistical analysis.</p><p><strong>Results: </strong>LiSi showed fine dense crystals 1 to 1.5 μm in size, while e.max showed long rod-shaped crystals 3 to 4 μm in size. The TP values of all specimens coincided with their translucency levels. There was no statistical difference in the KIc between different translucency for both ceramics (P < .05). However, the KIc of e.max was significantly higher than that of LiSi at both translucency levels. As a result of larger and longer crystals, e.max provided better crack deviation mechanism to resist the fracture.</p><p><strong>Conclusions: </strong>Within the limitations of this study, the translucency levels of both lithium disilicate ceramics did not affect the fracture toughness of the materials. The fracture toughness of e.max was statistically higher than LiSi.</p>","PeriodicalId":94232,"journal":{"name":"The International journal of prosthodontics","volume":"0 0","pages":"254-266"},"PeriodicalIF":0.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41242848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"WEAR, FATIGUE, AND FRACTURE RESISTANCE OF DIFFERENT MONOLITHIC CAD/CAM ONLAYS AS ABUTMENTS FOR ACETAL RESIN OR COBALT-CHROMIUM REMOVABLE PARTIAL DENTURE FRAMEWORKS.","authors":"Hiba A Alshaiba, Nadia Khalifa, Zeina Al Doory, Hatem M El-Damanhoury","doi":"10.11607/ijp.8641","DOIUrl":"10.11607/ijp.8641","url":null,"abstract":"<p><strong>Purpose: </strong>To assess wear, fatigue, and fracture resistance of different CAD/CAM onlays milled from monolithic zirconia (ZR), hybrid ceramic (EN), and lithium disilicate (LS) when used as abutments for removable partial denture frameworks fabricated from acetal resin (AR) or cobalt-chromium (Co-Cr).</p><p><strong>Materials and methods: </strong>Standard onlays and RPD framework were designed and milled using CAD/CAM. Onlays were cemented with resin cement to identical teeth models. The RPD's occlusal rest surface and the ceramic onlays' rest seats were both 3D scanned before and aPer 750,000 mechanical load cycles (50 N) and 8,000 thermal cycles (5° to 55°C) in a chewing simulator. The volumetric loss was measured using 3D-image processing software, and the failure of the samples was detected using a stereomicroscope. The fracture resistance was tested by loading to failure in a universal testing machine. The fatigue failure results were analyzed with Fisher exact probability test, and the wear and fracture resistance data were analyzed using twoway ANOVA and Bonferroni post-hoc test (P < .05).</p><p><strong>Results: </strong>A significant difference (P < .05) was found between the tested experimental groups in wear, fatigue, and fracture resistance. Zr/Co-Cr combinations exhibited the least wear and the highest fatigue and fracture resistance (P < .05), while the highest wear and least fatigue and fracture resistance were recorded for the EN/AR group (P < .05).</p><p><strong>Conclusions: </strong>Zr onlays demonstrated a conserva&#43;ve treatment option with superior mechanical behavior when used as an onlay abutment, regardless of the RPD framework material used. The AR framework is not recommended in the posterior region for removable partial dentures.</p>","PeriodicalId":94232,"journal":{"name":"The International journal of prosthodontics","volume":"0 0","pages":"228-243"},"PeriodicalIF":0.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41144703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improving Fracture Resistance of 5Y-PSZ-Based Three-Unit Bridge Prostheses.","authors":"Jae Won Kim, Tung Van Vo, Megha Satpathy, Raj Malyala","doi":"10.11607/ijp.8643","DOIUrl":"10.11607/ijp.8643","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the effect of BruxZir Steel treatment on the fracture resistance of zirconia threeunit bridges prepared using 5Y-PSZ-based zirconia blanks.</p><p><strong>Materials and methods: </strong>Three-unit zirconia bridges were milled using CAD/CAM from homogeneous bisque zirconia blanks (5Y-PSZ-based) supplied by various manufacturers and sintered. Fracture resistance was analyzed with dynamic loading. For each zirconia blank, the fracture resistance of the sintered test restoration (cementation surface treated with BruxZir Steel) was compared to the sintered control restoration (untreated cementation surface). Finite element analysis (FEA) was used to analyze the stress distribution on the three-unit bridge under an axial load.</p><p><strong>Results: </strong>The fracture resistance of the test restorations was significantly higher than that of the control restorations for all manufacturers considered in this study (P < .05). Furthermore, the restoration made of BruxZir Esthetic treated with BruxZir Steel had the highest fracture resistance compared to the other restorations. In addition, the three-unit bridge restorations prepared from 5Y-PSZ-based zirconia blanks exhibited differences in grain size and fracture toughness depending on the presence or absence of BruxZir Steel treatment. The locations of high stresses under FEA correlated well with the fracture locations in the corresponding experimental test. FEA also demonstrated the improved performance of the BruxZir Steel-treated sample compared to the control.</p><p><strong>Conclusions: </strong>The fracture resistance of 5Y-PSZ-based BruxZir Steel-treated three-unit bridges was significantly higher (min = 30%, max = 198%) than the control.</p>","PeriodicalId":94232,"journal":{"name":"The International journal of prosthodontics","volume":"0 0","pages":"650-658"},"PeriodicalIF":0.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41224448","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recycling CAD/CAM Lithium Disilicate Ceramic: Effect of Surface Treatment and Aging on the Bond Strength to Resin Cement.","authors":"Larissa Mendonça de Miranda, Aparecida Tharlla Leite Caldas, Dayanne Monielle Duarte Moura, Karina Barbosa Souza, Isauremi Vieira de Assunção, Mutlu Özcan, Rodrigo Othávio de Assunção E Souza","doi":"10.11607/ijp.8677","DOIUrl":"10.11607/ijp.8677","url":null,"abstract":"<p><strong>Purpose: </strong>To investigate the effects of recycling lithium disilicate (LD), surface treatment, and thermocycling on the bond strength to resin cement.</p><p><strong>Materials and methods: </strong>A total of 72 tablets (10 × 10 × 3 mm) of LD were made according to the recycling cycle with 24 tablets for each strategy: control (conventional sintering), 1R (1 recycling cycle), and 3R (3 recycling cycles). For the recycling groups, tablets were waxed, mounted in a silicone ring, and poured with investment material, and residues of sintered LD tablets were pressed by the lost wax technique. The residual LD was reused as described until it reached 3R. Afterward, the tablets were embedded in acrylic resin, sanded, and divided (n = 15) according to the factors of 'surface treatment' (hydrofluoric acid [HF] for 20 seconds [HF20s] and silane, HF for 120 seconds [HF120s] and silane, and Monobond Etch & Prime [MEP]) and thermocycling (TC; with 10,000 cycles and without). After surface treatment, cylinders (diameter: 2 mm) of resin cement were made and submitted to SBS test (100 kgf, 1 mm/minute). Data (MPa) were analyzed by three-way ANOVA, Tukey test (5%), and Weibull analysis. Failure analysis was performed with a stereomicroscope.</p><p><strong>Results: </strong>ANOVA revealed that all factors were significant (P = .000*). The group 3RMEP (105.09 ± 19.49) presented the highest SBS among the experimental groups. The 1RHF20sTc (7.50 ± 1.97) group had the lowest SBS, similar to CHF20sTc (15.69 ± 3.77), 1RHF20s (15.12 ± 3.03), 1RHF120sTc (14.60 ± 3.43), and 3RHF20sTc (15.65 ± 0.97). The Weibull modulus and characteristic strength varied among the experimental groups (P = .0). Failure analysis revealed adhesive and mixed types.</p><p><strong>Conclusions: </strong>The recycling of DL ceramics increases the SBS to resin cement when the ceramic is treated with HF120s and silane or MEP.</p>","PeriodicalId":94232,"journal":{"name":"The International journal of prosthodontics","volume":"0 0","pages":"675-685"},"PeriodicalIF":0.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41224508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oral Prosthetic Rehabilitation in Patients with Epidermolysis Bullosa Hereditaria: A Systematic Review.","authors":"Salomé Mascarell, Hélène Citterio, Énora Le Roux, Ariane Berdal, Géraldine Lescaille, Lisa Friedlander","doi":"10.11607/ijp.8791","DOIUrl":"10.11607/ijp.8791","url":null,"abstract":"<p><strong>Purpose: </strong>To review the oral prosthetic rehabilitation of patients with epidermolysis bullosa hereditaria (EBH) and study the level of evidence and quality of the presented available articles and establish clinical recommendations for the prosthetic management of these patients.</p><p><strong>Materials and methods: </strong>An electronic search was done in July 2022 in five databases following PICOTS elements. The quality of the reports was established using the modified Pierson, Bradford Hills, and Ottawa Newcastle scale.</p><p><strong>Results: </strong>Data extracted from 19 case reports for protocolized analysis corresponded to 64 patients and 80 dental prostheses, with almost 9 out of 10 patients being completely edentulous. The distribution of EBH types was 84% dystrophic, 10.5% junctional, and 5.5% simplex. The difficulties encountered by the authors synthesized in this review characteristically reflected those most likely encountered in dental practice. Most rehabilitations were implant-supported prostheses (85%), followed by removable dentures (10%) and dental-supported rehabilitations (5%). Fixed full-arch implant-supported prostheses represented 76.4% of implant-supported prostheses, and this prosthetic solution reflected the highest scientific quality.</p><p><strong>Conclusions: </strong>For an individualized approach to treatment, we recommend that in cases of total edentulism, fixed full-arch implant-supported prostheses are the most appropriate because they allow the best computer-aided planning, design, manufacture, and fitting of the prosthesis in such a complex clinical context.</p>","PeriodicalId":94232,"journal":{"name":"The International journal of prosthodontics","volume":"0 0","pages":"699-710"},"PeriodicalIF":0.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138813873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does an Ergonomic Dentist Stool Design Have a Positive Impact on Musculoskeletal Health During Intraoral Scans and Tooth Preparation?","authors":"Ji-Min Lee, Keunbada Son, Jin-Wook Kim, Myoung-Uk Jin, Kyu-Bok Lee","doi":"10.11607/ijp.8672","DOIUrl":"10.11607/ijp.8672","url":null,"abstract":"<p><strong>Purpose: </strong>To evaluate the effects of an ergonomic dentist stool design on muscle activity and fatigue in dentists.</p><p><strong>Materials and methods: </strong>A total of 14 dentists were recruited, and electrodes were attached to the arm, neck, and shoulder muscles of these dentists according to the surface electromyography (EMG) for the noninvasive assessment of muscles protocol. After measuring the maximal voluntary contraction, eightchannel surface EMG was performed during simulations of two dental procedures (intraoral scanning and tooth preparation) while the dentists were using two types of dentist stools. Furthermore, muscle activity and fatigue were determined based on eight-channel surface EMG data, and ergonomic risk levels were evaluated according to the muscle activity. Shapiro-Wilk test was used to confirm that all data were normally distributed, and Mann-Whitney U test was used to compare the two types of dentist stools (α = .05).</p><p><strong>Results: </strong>There was a significant difference between the conventional and ergonomically designed dentist stools in terms of the activity of the trapezius descendens muscle (P < .05). Notably, the activity of the trapezius descendens muscle was less when the dentists used ergonomically designed dentist stools than when they used a conventional dentist stool. The activity of all muscles, except for the sternocleidomastoid, indicated moderate ergonomic risk.</p><p><strong>Conclusions: </strong>A dentist stool that enables dentists to maintain ergonomic posture should be used to prevent musculoskeletal disorders.</p>","PeriodicalId":94232,"journal":{"name":"The International journal of prosthodontics","volume":"0 0","pages":"644-649"},"PeriodicalIF":0.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138292637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}