Pub Date : 2025-12-01DOI: 10.1016/j.prosdent.2024.12.016
Noha Taymour BDS, MSc, PhD , Shaimaa M. Fouda BDS, MSc, PhD , Hams H. Abdelrahaman BDS, MSc , Mohamed G. Hassan BDS, MSc, PhD
Statement of problem
Artificial intelligence (AI) chatbots have been proposed as promising resources for oral health information. However, the quality and readability of existing online health-related information is often inconsistent and challenging.
Purpose
This study aimed to compare the reliability and usefulness of dental implantology-related information provided by the ChatGPT-3.5, ChatGPT-4, and Google Gemini large language models (LLMs).
Material and methods
A total of 75 questions were developed covering various dental implant domains. These questions were then presented to 3 different LLMs: ChatGPT-3.5, ChatGPT-4, and Google Gemini. The responses generated were recorded and independently assessed by 2 specialists who were blinded to the source of the responses. The evaluation focused on the accuracy of the generated answers using a modified 5-point Likert scale to measure the reliability and usefulness of the information provided. Additionally, the ability of the AI-chatbots to offer definitive responses to closed questions, provide reference citation, and advise scheduling consultations with a dental specialist was also analyzed. The Friedman, Mann Whitney U and Spearman Correlation tests were used for data analysis (α=.05).
Results
Google Gemini exhibited higher reliability and usefulness scores compared with ChatGPT-3.5 and ChatGPT-4 (P<.001). Google Gemini also demonstrated superior proficiency in identifying closed questions (25 questions, 41%) and recommended specialist consultations for 74 questions (98.7%), significantly outperforming ChatGPT-4 (30 questions, 40.0%) and ChatGPT-3.5 (28 questions, 37.3%) (P<.001). A positive correlation was found between reliability and usefulness scores, with Google Gemini showing the strongest correlation (ρ=.702).
Conclusions
The 3 AI Chatbots showed acceptable levels of reliability and usefulness in addressing dental implant-related queries. Google Gemini distinguished itself by providing responses consistent with specialist consultations.
{"title":"Performance of the ChatGPT-3.5, ChatGPT-4, and Google Gemini large language models in responding to dental implantology inquiries","authors":"Noha Taymour BDS, MSc, PhD , Shaimaa M. Fouda BDS, MSc, PhD , Hams H. Abdelrahaman BDS, MSc , Mohamed G. Hassan BDS, MSc, PhD","doi":"10.1016/j.prosdent.2024.12.016","DOIUrl":"10.1016/j.prosdent.2024.12.016","url":null,"abstract":"<div><h3>Statement of problem</h3><div>Artificial intelligence (AI) chatbots have been proposed as promising resources for oral health information. However, the quality and readability of existing online health-related information is often inconsistent and challenging.</div></div><div><h3>Purpose</h3><div>This study aimed to compare the reliability and usefulness of dental implantology-related information provided by the ChatGPT-3.5, ChatGPT-4, and Google Gemini large language models (LLMs).</div></div><div><h3>Material and methods</h3><div>A total of 75 questions were developed covering various dental implant<span> domains. These questions were then presented to 3 different LLMs: ChatGPT-3.5, ChatGPT-4, and Google Gemini. The responses generated were recorded and independently assessed by 2 specialists who were blinded to the source of the responses. The evaluation focused on the accuracy of the generated answers using a modified 5-point Likert scale to measure the reliability and usefulness of the information provided. Additionally, the ability of the AI-chatbots to offer definitive responses to closed questions, provide reference citation, and advise scheduling consultations with a dental specialist was also analyzed. The Friedman, Mann Whitney U and Spearman Correlation tests were used for data analysis (α=.05).</span></div></div><div><h3>Results</h3><div>Google Gemini exhibited higher reliability and usefulness scores compared with ChatGPT-3.5 and ChatGPT-4 (<em>P</em><.001). Google Gemini also demonstrated superior proficiency in identifying closed questions (25 questions, 41%) and recommended specialist consultations for 74 questions (98.7%), significantly outperforming ChatGPT-4 (30 questions, 40.0%) and ChatGPT-3.5 (28 questions, 37.3%) (<em>P</em><.001). A positive correlation was found between reliability and usefulness scores, with Google Gemini showing the strongest correlation (ρ=.702).</div></div><div><h3>Conclusions</h3><div>The 3 AI Chatbots showed acceptable levels of reliability and usefulness in addressing dental implant-related queries. Google Gemini distinguished itself by providing responses consistent with specialist consultations.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"134 6","pages":"Pages 2427-2434"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142932185","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}
Pub Date : 2025-12-01DOI: 10.1016/j.prosdent.2024.12.005
Hanin Sager Hammoudeh DDS, MS , Lisa A. Lang DDS, MS, MBA , Paola C. Saponaro DDS, MS , Scott D. Barnett PhD, MSPH , Leonardo Mohamad Nassani DMD, MBA , Shereen A. Azer BDS, MSc, MS , Yuan-Lynn Hsieh DDS, MS
Statement of problem
Although immediate implant loading has shown promising clinical results and high survival rates, an increased risk of implant failure and complications has been reported. Achieving consistently predictable outcomes with this approach remains a challenge, but evidence-based guidelines to assist in selecting suitable patients are lacking.
Purpose
The purpose of this retrospective clinical study was to investigate the success rate, survival rate, and complications of immediate implant loading compared with early and delayed loading. Also, it sought to identify the potential risk factors of immediate implant loading.
Material and methods
Dental records for dental implants that were surgically placed at 1 center between January 2016 and October 2021 were reviewed for different loading protocols. Time from surgical placement to load was calculated, and the implants were divided into 3 groups: immediate (IL: <3 weeks), early (EL: 3 weeks to 3 months), and delayed (DL: >3 months). Patient, procedural, and restorative parameters were also recorded. Adverse events reported were implant failure and mechanical and biological complications, and the incident rates per 100 person-years (100 PY) for each adverse event were calculated. The Kaplan-Meier and Cox Proportional Hazards models with time to event approach were stratified by time-to-load (unit of analysis: the implant). Five-year survival rates were evaluated with Kaplan-Meier survival estimates. All statistical analyses were completed with a statistical software program (α=.05).
Results
A total of 258 implants (20.1%) were in the IL group, 24 implants (1.9%) in the EL group, and 985 implants (76.8%) in the DL group. The incident rate of any adverse event was 3-fold more among implants in the IL group and EL groups as compared with the DL group (21.0/100 PY, 19/100 PY, 5.8/100 PY, respectively). Immediate implant loading was a significant predictor of implant failure (IL, HR: 30.94; 95% CI: 8.23–116.36, P=.001), failure to osseointegrate (IL, HR: 215.66; 95% CI: 7.17.98–2598, P=.001), loss of osseointegration (IL, HR: 23.77; 95% CI: 6.32–89.48, P=.001), any mechanical complications (IL, HR: 0.32; 95% CI: 0.11–0.93, P=.036), and peri-implantitis (IL, HR: 17.02; 95% CI: 1.54–17.02, P=.008). The 5-year survival rates of IL versus DL for any implant failure were 60% versus 99% and for peri-implantitis were 91% versus 99%. Diabetes and moderate periodontitis were associated with increased implant failure in the IL group.
Conclusions
Immediate loading was a significant predictor of implant failure, mechanical complication, and peri-implantitis. Diabetes and moderate periodontitis might be risk factors with immediate loading.
{"title":"Effect of implant loading protocols and associated factors on the success rate of implant therapy: A retrospective clinical study","authors":"Hanin Sager Hammoudeh DDS, MS , Lisa A. Lang DDS, MS, MBA , Paola C. Saponaro DDS, MS , Scott D. Barnett PhD, MSPH , Leonardo Mohamad Nassani DMD, MBA , Shereen A. Azer BDS, MSc, MS , Yuan-Lynn Hsieh DDS, MS","doi":"10.1016/j.prosdent.2024.12.005","DOIUrl":"10.1016/j.prosdent.2024.12.005","url":null,"abstract":"<div><h3>Statement of problem</h3><div>Although immediate implant loading has shown promising clinical results and high survival rates, an increased risk of implant failure and complications has been reported. Achieving consistently predictable outcomes with this approach remains a challenge, but evidence-based guidelines to assist in selecting suitable patients are lacking.</div></div><div><h3>Purpose</h3><div>The purpose of this retrospective clinical study was to investigate the success rate, survival rate, and complications of immediate implant loading compared with early and delayed loading. Also, it sought to identify the potential risk factors of immediate implant loading.</div></div><div><h3>Material and methods</h3><div>Dental records for dental implants<span> that were surgically placed at 1 center between January 2016 and October 2021 were reviewed for different loading protocols. Time from surgical placement to load was calculated, and the implants were divided into 3 groups: immediate (IL: <3 weeks), early (EL: 3 weeks to 3 months), and delayed (DL: >3 months). Patient, procedural, and restorative parameters were also recorded. Adverse events reported were implant failure and mechanical and biological complications, and the incident rates per 100 person-years (100 PY) for each adverse event were calculated. The Kaplan-Meier and Cox Proportional Hazards models with time to event approach were stratified by time-to-load (unit of analysis: the implant). Five-year survival rates were evaluated with Kaplan-Meier survival estimates. All statistical analyses were completed with a statistical software program (α=.05).</span></div></div><div><h3>Results</h3><div>A total of 258 implants (20.1%) were in the IL group, 24 implants (1.9%) in the EL group, and 985 implants (76.8%) in the DL group. The incident rate of any adverse event was 3-fold more among implants in the IL group and EL groups as compared with the DL group (21.0/100 PY, 19/100 PY, 5.8/100 PY, respectively). Immediate implant loading was a significant predictor of implant failure (IL, HR: 30.94; 95% CI: 8.23–116.36, <em>P</em>=.001), failure to osseointegrate (IL, HR: 215.66; 95% CI: 7.17.98–2598, <em>P</em><span>=.001), loss of osseointegration (IL, HR: 23.77; 95% CI: 6.32–89.48, </span><em>P</em>=.001), any mechanical complications (IL, HR: 0.32; 95% CI: 0.11–0.93, <em>P</em>=.036), and peri-implantitis (IL, HR: 17.02; 95% CI: 1.54–17.02, <em>P</em><span>=.008). The 5-year survival rates of IL versus DL for any implant failure were 60% versus 99% and for peri-implantitis were 91% versus 99%. Diabetes and moderate periodontitis were associated with increased implant failure in the IL group.</span></div></div><div><h3>Conclusions</h3><div>Immediate loading was a significant predictor of implant failure, mechanical complication, and peri-implantitis. Diabetes and moderate periodontitis might be risk factors with immediate loading.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"134 6","pages":"Pages 2281-2293"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142927026","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}
Pub Date : 2025-12-01DOI: 10.1016/j.prosdent.2025.01.040
Panagiotis Ntovas DDS, MSc , Ourania Ladia DDS , Abdul B. Barmak MD, MSc, EdD , John C. Kois DMD, MSD , Marta Revilla-León DDS, MSD, PhD
Statement of problem
Digitized analog records have been used for the superimposition of intraoral and facial scans. However, the discrepancy in the registration between the digitized occlusal records contained on extraoral scan bodies and the maxillary virtual cast remains uncertain.
Purpose
The purpose of this in vitro study was to evaluate the effect of the registration method, edentulous area, and tooth anatomy on the accuracy of the alignment between the digitized extraoral scan body (ESB) and the maxillary virtual cast.
Material and methods
A scannable ESB and a set of 8 maxillary casts (2 completely dentate simulating unworn and worn tooth anatomy, 5 partially edentulous, and 1 completely edentulous were printed (Pro 95S; SprintRay). Four zirconia markers were attached to the index of the ESB and each of the evaluated casts. Each cast was positioned into the tray of the ESB using occlusal registration material (O-Bite; DMG). The ESB and each corresponding evaluated cast were digitized by using a calibrated laboratory scanner (T710; Medit). Then, each cast and index of the ESB were scanned separately by using the same scanner (n=10). Using a CAD software program, each virtual cast was attached to the ESB 10 times by using 3 different alignment methods: an analog using an iterative closest points (ICP) algorithm and 2 semimanual alignments using a best-fit algorithm for the entire data set with or without including the edentulous areas. A metrology software program was used to measure the linear distance between the corresponding gauge balls and the angulation between the planes defined by the markers on the cast and the ESB. The measurements from the scans of the casts attached to the tray were used as a reference to calculate the discrepancies in each experimental group. Α P value threshold of <.05 was used to determine statistical significance.
Results
The best-fit algorithm registration method produced better trueness and precision than the manual point-to-point registration (P<.05). When the edentulous areas were not included in the analog surface record, the trueness and precision of the best-fit algorithm were significantly worse (P<.05). In respect of tooth anatomy, no significant difference in trueness and precision was found among the investigated groups (P>.05). The completely dentate groups presented significantly better trueness than the edentulous groups (P<.05).
Conclusions
The accuracy of the registration between digitized occlusal surface scans and digital casts was influenced by the registration method, as well as by the location and extent of the edentulous areas.
{"title":"Accuracy of registration between digitized extraoral scan bodies and virtual casts: Effect of the edentulous area, tooth anatomy, and registration method","authors":"Panagiotis Ntovas DDS, MSc , Ourania Ladia DDS , Abdul B. Barmak MD, MSc, EdD , John C. Kois DMD, MSD , Marta Revilla-León DDS, MSD, PhD","doi":"10.1016/j.prosdent.2025.01.040","DOIUrl":"10.1016/j.prosdent.2025.01.040","url":null,"abstract":"<div><h3>Statement of problem</h3><div>Digitized analog records have been used for the superimposition of intraoral and facial scans. However, the discrepancy in the registration between the digitized occlusal records contained on extraoral scan bodies and the maxillary virtual cast remains uncertain.</div></div><div><h3>Purpose</h3><div>The purpose of this in vitro study was to evaluate the effect of the registration method, edentulous area, and tooth anatomy on the accuracy of the alignment between the digitized extraoral scan body (ESB) and the maxillary virtual cast.</div></div><div><h3>Material and methods</h3><div><span><span>A scannable ESB and a set of 8 maxillary casts (2 completely dentate simulating unworn and worn tooth anatomy, 5 partially edentulous, and 1 completely edentulous were printed (Pro 95S; SprintRay). Four zirconia markers were attached to the index of the ESB and each of the evaluated casts. Each cast was positioned into the tray of the ESB using occlusal registration material (O-Bite; DMG). The ESB and each corresponding evaluated cast were digitized by using a calibrated laboratory scanner (T710; Medit). Then, each cast and index of the ESB were scanned separately by using the same scanner (n=10). Using a CAD software program, each virtual cast was attached to the ESB 10 times by using 3 different alignment methods: an analog using an iterative closest points (ICP) algorithm and 2 semimanual alignments using a best-fit algorithm for the entire data set with or without including the edentulous areas. A metrology software program was used to measure the linear distance between the corresponding gauge balls and the </span>angulation between the planes defined by the markers on the cast and the ESB. The measurements from the scans of the casts attached to the tray were used as a reference to calculate the discrepancies in each experimental group. Α </span><em>P</em> value threshold of <.05 was used to determine statistical significance.</div></div><div><h3>Results</h3><div>The best-fit algorithm registration method produced better trueness and precision than the manual point-to-point registration (<em>P</em><.05). When the edentulous areas were not included in the analog surface record, the trueness and precision of the best-fit algorithm were significantly worse (<em>P</em><.05). In respect of tooth anatomy, no significant difference in trueness and precision was found among the investigated groups (<em>P</em>>.05). The completely dentate groups presented significantly better trueness than the edentulous groups (<em>P</em><.05).</div></div><div><h3>Conclusions</h3><div>The accuracy of the registration between digitized occlusal surface scans and digital casts was influenced by the registration method, as well as by the location and extent of the edentulous areas.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"134 6","pages":"Pages 2500-2507"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143523774","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}
Pub Date : 2025-12-01DOI: 10.1016/j.prosdent.2025.02.011
Sara Garcia-Gomez DDS , Jesús Maneiro-Lojo DDS , Jorge Alonso Pérez-Barquero DDS, PhD , John C. Kois DMD, MSD , Lucía Fernandez-Estevan DDS, PhD , Marta Revilla-León DDS, MSD, PhD
<div><h3>Statement of problem</h3><div><span>Studies analyzing the accuracy of intraoral scanners (IOSs) for fabricating veneer restorations are scarce. Also, the space between </span>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.</div></div><div><h3>Purpose</h3><div>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.</div></div><div><h3>Material and methods</h3><div>A maxillary model with the 6 anterior teeth<span> with a veneer preparation on both central incisors<span> 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).</span></span></div></div><div><h3>Results</h3><div>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 (<em>P</em><.001) and subgroups (<em>P</em><.001), with a significant interaction between group×subgroup (<em>P</em><.001). In the 0.5 group, there were trueness (<em>P</em><.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 (<em>P</em><.001). The inexperienced operator revealed lower trueness when scanning the 0.5-mm cast when compared with the 1.0- (<em>P</em><.001) and 1.5-mm (<em>P</em><.001) casts. Scanning time discrepancies were revealed between the operators in the 1.0 (<em>P</em><.001) and 1.5 groups (<em>P</em><.001). For the inexperienced operator, the 1.0 and 1.5 groups (<em>P</em><.001) were significantly different. Number of photogram discrepancies were revealed between the operators in the 1.0 group (<em>P</em><.001) and 1.5 group (<em>P</em><.001). Additionally, for the inexperienced operator, the 1.0 and 1.5 groups were significantly differ
{"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 DDS , Jesús Maneiro-Lojo DDS , Jorge Alonso Pérez-Barquero DDS, PhD , John C. Kois DMD, MSD , Lucía Fernandez-Estevan DDS, PhD , Marta Revilla-León DDS, MSD, PhD","doi":"10.1016/j.prosdent.2025.02.011","DOIUrl":"10.1016/j.prosdent.2025.02.011","url":null,"abstract":"<div><h3>Statement of problem</h3><div><span>Studies analyzing the accuracy of intraoral scanners (IOSs) for fabricating veneer restorations are scarce. Also, the space between </span>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.</div></div><div><h3>Purpose</h3><div>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.</div></div><div><h3>Material and methods</h3><div>A maxillary model with the 6 anterior teeth<span> with a veneer preparation on both central incisors<span> 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).</span></span></div></div><div><h3>Results</h3><div>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 (<em>P</em><.001) and subgroups (<em>P</em><.001), with a significant interaction between group×subgroup (<em>P</em><.001). In the 0.5 group, there were trueness (<em>P</em><.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 (<em>P</em><.001). The inexperienced operator revealed lower trueness when scanning the 0.5-mm cast when compared with the 1.0- (<em>P</em><.001) and 1.5-mm (<em>P</em><.001) casts. Scanning time discrepancies were revealed between the operators in the 1.0 (<em>P</em><.001) and 1.5 groups (<em>P</em><.001). For the inexperienced operator, the 1.0 and 1.5 groups (<em>P</em><.001) were significantly different. Number of photogram discrepancies were revealed between the operators in the 1.0 group (<em>P</em><.001) and 1.5 group (<em>P</em><.001). Additionally, for the inexperienced operator, the 1.0 and 1.5 groups were significantly differ","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"134 6","pages":"Pages 2391-2398"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","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}
Pub Date : 2025-12-01DOI: 10.1016/j.prosdent.2025.10.007
Marta Revilla-León DDS, MSD, PhD
Implant scanning workflows have 2 pillars: the elements (scans) and the reference landmarks (Fig. 1). The elements of a workflow are the scans containing different information needed to design and fabricate an implant prosthesis by using digital technologies. Therefore, an implant scanning workflow has 5 elements or scans containing the following information: tooth, tissue, and implant positions of the arch being restored, antagonist scan, and maxillomandibular relationship.1 The reference landmarks include any device, anatomical structure, and supportive image that allow the alignment of the scans of an implant scanning workflow.2 Seven different reference landmarks: anatomical structures, artificial references, interim restorations, teeth, fixation screws, implant scan bodies, and cone beam computed tomography images have been described.2, 3, 4 The reference landmark selected to register the tooth and tissue scans has been called the predominant landmark. The concept of the implant pentagon for representing and standardizing the implant scanning workflows is introduced. Each corner of the pentagon represents one of the elements of the implant workflow. The implant scanning technique is represented in the top of the implant pentagon, while the predominant landmark is symbolized in the center of the implant pentagon. The implant pentagon has the capability to represent all the possible implant scanning workflows.
{"title":"Implant scanning workflows: The implant pentagon","authors":"Marta Revilla-León DDS, MSD, PhD","doi":"10.1016/j.prosdent.2025.10.007","DOIUrl":"10.1016/j.prosdent.2025.10.007","url":null,"abstract":"<div><div>Implant scanning workflows have 2 pillars: the elements (scans) and the reference landmarks (<span><span>Fig. 1</span></span>). The elements of a workflow are the scans containing different information needed to design and fabricate an implant prosthesis by using digital technologies. Therefore, an implant scanning workflow has 5 elements or scans containing the following information: tooth, tissue, and implant positions of the arch being restored, antagonist scan, and maxillomandibular relationship.<span><span><sup>1</sup></span></span> The reference landmarks include any device, anatomical structure, and supportive image that allow the alignment of the scans of an implant scanning workflow.<span><span><sup>2</sup></span></span> Seven different reference landmarks: anatomical structures, artificial references, interim restorations, teeth, fixation screws, implant scan bodies, and cone beam computed tomography images have been described.<span><span>2</span></span>, <span><span>3</span></span>, <span><span>4</span></span> The reference landmark selected to register the tooth and tissue scans has been called the predominant landmark. The concept of the implant pentagon for representing and standardizing the implant scanning workflows is introduced. Each corner of the pentagon represents one of the elements of the implant workflow. The implant scanning technique is represented in the top of the implant pentagon, while the predominant landmark is symbolized in the center of the implant pentagon. The implant pentagon has the capability to represent all the possible implant scanning workflows.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"134 6","pages":"Pages 2028-2029"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145431622","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}
Recent studies have reported a significant correlation between the implant restoration contour and marginal bone loss (MBL). However, studies evaluating the relationship between the contour of implant restoration and marginal bone loss in subcrestally placed implants are lacking.
Purpose
The purpose of this retrospective study was to evaluate the relationship between the profile angle, measured from the implant platform and the adjacent crestal bone level as references, and the amount of MBL in subcrestally placed implants.
Material and methods
This retrospective study included 167 posterior single-tooth implant restorations with computer-aided design and computer-aided manufacturing (CAD-CAM) abutments by searching the electronic medical records of patients in regular maintenance. Among the 167 implants, 84 were placed more than 1 mm subcrestally in 76 patients, while 83 were placed equicrestally in 73 patients. The measurement of profile angles (PAs) was classified into 3 groups: EI Group: PA measured from the implant platform in equicrestally placed implants, SI Group: PA measured from the implant platform in subcrestally placed implants, and SB Group: PA measured from the adjacent bone crest in subcrestally placed implants. MBL changes were evaluated at different time points by measuring the distance between the implant shoulder and the first bone-to-implant contact. The Pearson correlation and linear regression analysis was used to evaluate the relationship between PA and marginal bone loss at different distance ranges. C-index analysis identified cut-off points of PA for 0 to 1, 1 to 2, and 2 to 3 mm distance ranges, and independent t tests evaluated statistical differences based on these cut-off points (α=.05 for all tests).
Results
EI and SB groups resulted in significant correlations between PA and MBL at 0 to 1 and 1 to 2 mm distance ranges (P<.05), but no significant correlation at 2 to 3 mm ranges (P>.05). In contrast, significant correlations were found between PA and MBL in the SI group at all distance ranges (0 to 1, 1 to 2, and 2 to 3 mm). In general, the SI groups showed smaller cut-off values than the EI or SB group at the corresponding distance ranges.
Conclusions
In subcrestally or equicrestally placed posterior single-tooth implants, the profile angles within 2 mm from the bone crest significantly correlated with marginal bone loss. When the profile angles were measured from the implant platform as references, the profile angle measured 0 to 3 mm from the reference correlated with marginal bone loss in subcrestally placed implants.
{"title":"The link between abutment configuration and marginal bone loss in subcrestally placed posterior implant-supported restorations","authors":"Jung-Hyun Nam DDS , Jaeseung Chang DDS, MSD, PhD , Se-Wook Pyo DDS, MSD, PhD , Sunjai Kim DDS, MSD, PhD","doi":"10.1016/j.prosdent.2025.01.010","DOIUrl":"10.1016/j.prosdent.2025.01.010","url":null,"abstract":"<div><h3>Statement of problem</h3><div><span>Recent studies have reported a significant correlation between the implant restoration contour and </span>marginal bone loss (MBL). However, studies evaluating the relationship between the contour of implant restoration and marginal bone loss in subcrestally placed implants are lacking.</div></div><div><h3>Purpose</h3><div>The purpose of this retrospective study was to evaluate the relationship between the profile angle, measured from the implant platform and the adjacent crestal bone level as references, and the amount of MBL in subcrestally placed implants.</div></div><div><h3>Material and methods</h3><div><span><span>This retrospective study included 167 posterior single-tooth implant restorations with computer-aided design and computer-aided manufacturing (CAD-CAM) abutments by searching the electronic medical records of patients in regular maintenance. Among the 167 implants, 84 were placed more than 1 mm subcrestally in 76 patients, while 83 were placed equicrestally in 73 patients. The measurement of profile angles (PAs) was classified into 3 groups: EI Group: PA measured from the implant platform in equicrestally placed implants, SI Group: PA measured from the implant platform in subcrestally placed implants, and SB Group: PA measured from the adjacent bone crest in subcrestally placed implants. MBL changes were evaluated at different time points by measuring the distance between the implant shoulder and the first bone-to-implant contact. The Pearson correlation and </span>linear regression analysis was used to evaluate the relationship between PA and marginal bone loss at different distance ranges. C-index analysis identified cut-off points of PA for 0 to 1, 1 to 2, and 2 to 3 mm distance ranges, and independent </span><em>t</em> tests evaluated statistical differences based on these cut-off points (α=.05 for all tests).</div></div><div><h3>Results</h3><div>EI and SB groups resulted in significant correlations between PA and MBL at 0 to 1 and 1 to 2 mm distance ranges (<em>P</em><.05), but no significant correlation at 2 to 3 mm ranges (<em>P</em>>.05). In contrast, significant correlations were found between PA and MBL in the SI group at all distance ranges (0 to 1, 1 to 2, and 2 to 3 mm). In general, the SI groups showed smaller cut-off values than the EI or SB group at the corresponding distance ranges.</div></div><div><h3>Conclusions</h3><div>In subcrestally or equicrestally placed posterior single-tooth implants, the profile angles within 2 mm from the bone crest significantly correlated with marginal bone loss. When the profile angles were measured from the implant platform as references, the profile angle measured 0 to 3 mm from the reference correlated with marginal bone loss in subcrestally placed implants.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"134 6","pages":"Pages 2256-2262"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143189263","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}
Pub Date : 2025-12-01DOI: 10.1016/j.prosdent.2025.01.012
Marta Revilla-León DDS, MSD, PhD , Miguel Gómez-Polo DDS, PhD , Abdul B. Barmak MD, MSc, EdD , John C. Kois DMD, MSD , Jorge Alonso Pérez-Barquero DDS, PhD
<div><h3>Statement of problem</h3><div>Intraoral scanners (IOSs) and artificial intelligence (AI) based programs can be used to locate the maximum intercuspal position (MIP). However, the influence of scan extension on the accuracy of the MIP located by using these technologies is uncertain.</div></div><div><h3>Purpose</h3><div>The purpose of this in vitro study was to analyze the effect of scan extension on the accuracy of the MIP located by using 3 IOSs and an AI-based program.</div></div><div><h3>Material and methods</h3><div>Stone casts mounted in an articulator<span> in MIP were digitized (T710). Two groups were created: complete- (CA group) and half arch (HA group) scan. In the CA-group, complete arch scans of the reference casts were captured with each IOS tested. The nonarticulated scans were duplicated 20 times. In the HA-groups, the right half arch scans of the reference casts were captured with each IOS tested. Six subgroups were generated: 3 IOS (Primescan-IOS, i700-IOS, and Aoralscan3-IOS) and 3 AI (Primescan-AI, i700-AI, and Aoralscan3-AI) subgroups. In the CA-Primescan-IOS subgroup, 10 duplicated scans were articulated in MIP by recording a bilateral occlusal record. In the CA-Primescan-AI subgroup, 10 duplicated scans were articulated in MIP by using an AI-based program (Bitefinder). In the CA-i700-IOS, CA-Aoralscan3-IOS, CA-i700-AI, and CA-Aoralscan3-AI subgroups, the same procedures as in the CA-Primescan-IOS and CA-Primescan-AI subgroups were completed, respectively. In the HA-Primescan-IOS subgroup, 10 duplicated scans were articulated in MIP by capturing a right occlusal record. In the HA-Primescan-AI subgroup, 10 duplicated scans were articulated in MIP by using the AI-based program. In the HA-i700-IOS, HA-Aoralscan3-IOS, HA-i700-AI, and HA-Aoralscan3-AI subgroups, the same procedures as in the HA-Primescan-IOS subgroups were completed, respectively. A program (Geomagic) was used to calculate 36 interlandmark measurements on the virtual articulated casts (control) and each specimen. Three-way ANOVA and Tukey tests were used to analyze trueness (α=.05). The Levene and pairwise multiple comparison tests were used to analyze precision (α=.05).</span></div></div><div><h3>Results</h3><div>MIP trueness discrepancies were found between the IOS (<em>P</em><.001), groups (<em>P</em><.001), and subgroups (<em>P</em><.001), with a significant interaction IOS×subgroup (<em>P</em><.001), group×subgroup (<em>P</em><.001), and IOS×group×subgroup (<em>P</em><.001). The Primescan and i700 (<em>P</em>=.014) and the Primescan and Aoralscan3 (<em>P</em><.001) were different from each other. The CA and HA groups (<em>P</em><.001) were different from each other. The IOS and AI subgroups (<em>P</em><.001) were different from each other. The Levene test showed significant precision discrepancies between the groups (<em>P</em><.001) and subgroups (<em>P</em><.001). The HA scans demonstrated significantly worse precis
{"title":"Influence of scan extension on the accuracy of maximum intercuspal position recorded by using intraoral scanners or an artificial intelligence-based program","authors":"Marta Revilla-León DDS, MSD, PhD , Miguel Gómez-Polo DDS, PhD , Abdul B. Barmak MD, MSc, EdD , John C. Kois DMD, MSD , Jorge Alonso Pérez-Barquero DDS, PhD","doi":"10.1016/j.prosdent.2025.01.012","DOIUrl":"10.1016/j.prosdent.2025.01.012","url":null,"abstract":"<div><h3>Statement of problem</h3><div>Intraoral scanners (IOSs) and artificial intelligence (AI) based programs can be used to locate the maximum intercuspal position (MIP). However, the influence of scan extension on the accuracy of the MIP located by using these technologies is uncertain.</div></div><div><h3>Purpose</h3><div>The purpose of this in vitro study was to analyze the effect of scan extension on the accuracy of the MIP located by using 3 IOSs and an AI-based program.</div></div><div><h3>Material and methods</h3><div>Stone casts mounted in an articulator<span> in MIP were digitized (T710). Two groups were created: complete- (CA group) and half arch (HA group) scan. In the CA-group, complete arch scans of the reference casts were captured with each IOS tested. The nonarticulated scans were duplicated 20 times. In the HA-groups, the right half arch scans of the reference casts were captured with each IOS tested. Six subgroups were generated: 3 IOS (Primescan-IOS, i700-IOS, and Aoralscan3-IOS) and 3 AI (Primescan-AI, i700-AI, and Aoralscan3-AI) subgroups. In the CA-Primescan-IOS subgroup, 10 duplicated scans were articulated in MIP by recording a bilateral occlusal record. In the CA-Primescan-AI subgroup, 10 duplicated scans were articulated in MIP by using an AI-based program (Bitefinder). In the CA-i700-IOS, CA-Aoralscan3-IOS, CA-i700-AI, and CA-Aoralscan3-AI subgroups, the same procedures as in the CA-Primescan-IOS and CA-Primescan-AI subgroups were completed, respectively. In the HA-Primescan-IOS subgroup, 10 duplicated scans were articulated in MIP by capturing a right occlusal record. In the HA-Primescan-AI subgroup, 10 duplicated scans were articulated in MIP by using the AI-based program. In the HA-i700-IOS, HA-Aoralscan3-IOS, HA-i700-AI, and HA-Aoralscan3-AI subgroups, the same procedures as in the HA-Primescan-IOS subgroups were completed, respectively. A program (Geomagic) was used to calculate 36 interlandmark measurements on the virtual articulated casts (control) and each specimen. Three-way ANOVA and Tukey tests were used to analyze trueness (α=.05). The Levene and pairwise multiple comparison tests were used to analyze precision (α=.05).</span></div></div><div><h3>Results</h3><div>MIP trueness discrepancies were found between the IOS (<em>P</em><.001), groups (<em>P</em><.001), and subgroups (<em>P</em><.001), with a significant interaction IOS×subgroup (<em>P</em><.001), group×subgroup (<em>P</em><.001), and IOS×group×subgroup (<em>P</em><.001). The Primescan and i700 (<em>P</em>=.014) and the Primescan and Aoralscan3 (<em>P</em><.001) were different from each other. The CA and HA groups (<em>P</em><.001) were different from each other. The IOS and AI subgroups (<em>P</em><.001) were different from each other. The Levene test showed significant precision discrepancies between the groups (<em>P</em><.001) and subgroups (<em>P</em><.001). The HA scans demonstrated significantly worse precis","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"134 6","pages":"Pages 2524-2533"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143374295","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}
Pub Date : 2025-12-01DOI: 10.1016/j.prosdent.2024.09.021
Wuwei Yin DDS, PhD , Yumeng Yang DDS, MSD , Rui Bao MSC in E&B , Xiao Chen DDS, MSD
Statement of problem
Poor or lack of adherence to supportive peri-implant therapy (SPIT) or supportive care has been associated with a significantly higher rate of peri-implantitis or peri-implant mucositis. However, whether therapy with or without the removal of an implant-supported prosthesis yields different outcomes remains unclear.
Purpose
The purpose of this clinical study was to evaluate the efficacy of ultrasonic devices in treating participants with or without the removal of implant-supported prostheses after more than 12 months of loading.
Material and methods
Twenty participants with 23 implant-supported fixed prostheses (39 implants) with indications for removal were included in this study. The following clinical parameters were recorded before the prostheses were removed: the maximum probing depth (PDmax), bleeding on probing (BOP), months of loading, and complications. Each prosthesis was removed and treated with a regular plaque indicator test and then reinserted. This was followed by the intraoral administration of regular supportive therapy via ultrasonically driven polyetheretherketone instrument tips. After instrumentation, the prostheses were removed to access the area positively stained for calculus or biofilm. PT0 and PT1 show the plaque coverage before and after intraoral ultrasonic cleaning, respectively. The reduction in the positive staining area and the efficacy of ultrasonic cleaning with or without prosthesis removal were measured. The Kolmogorov−Smirnov test was performed to verify that the sample data were normally distributed. Comparisons between PT0 and PT1 were conducted via paired t tests, followed by the Student t test for comparisons between groups (α=.05).
Results
A 27.3 ±15.0% reduction in plaque coverage was observed after the implant restorations had been cleaned intraorally. The efficacy of intraoral ultrasonic cleaning was only 45.4 ±20.6%, with a residual plaque rate of 54.6%. Cleaning without the removal of implant-supported restorations was less effective in participants with a PD >5 mm than in the other participants (P=.001). Neither the emergence angle nor the emergence profile had a significant influence on the cleaning effectiveness (P>.05).
Conclusions
Biofilms at the abutment−prosthesis connection and mucosal and proximal surfaces of the prosthesis may not be effectively cleaned by conventional SPIT. Biofilm reduction is improved by prosthesis removal when the PD is >5 mm.
{"title":"Necessity of removing implant-supported prostheses when conducting supportive peri-implant therapy: A clinical study","authors":"Wuwei Yin DDS, PhD , Yumeng Yang DDS, MSD , Rui Bao MSC in E&B , Xiao Chen DDS, MSD","doi":"10.1016/j.prosdent.2024.09.021","DOIUrl":"10.1016/j.prosdent.2024.09.021","url":null,"abstract":"<div><h3>Statement of problem</h3><div>Poor or lack of adherence to supportive peri-implant therapy (SPIT) or supportive care has been associated with a significantly higher rate of peri-implantitis or peri-implant mucositis. However, whether therapy with or without the removal of an implant-supported prosthesis yields different outcomes remains unclear.</div></div><div><h3>Purpose</h3><div>The purpose of this clinical study was to evaluate the efficacy of ultrasonic devices in treating participants with or without the removal of implant-supported prostheses after more than 12 months of loading.</div></div><div><h3>Material and methods</h3><div><span>Twenty participants with 23 implant-supported fixed prostheses (39 implants) with indications for removal were included in this study. The following clinical parameters were recorded before the prostheses were removed: the maximum probing depth (PDmax), bleeding on probing<span> (BOP), months of loading, and complications. Each prosthesis was removed and treated with a regular plaque indicator test and then reinserted. This was followed by the intraoral administration of regular supportive therapy via ultrasonically driven polyetheretherketone instrument tips. After instrumentation, the prostheses were removed to access the area positively stained for calculus or biofilm. PT0 and PT1 show the plaque coverage before and after intraoral ultrasonic cleaning, respectively. The reduction in the positive staining area and the efficacy of ultrasonic cleaning with or without prosthesis removal were measured. The Kolmogorov−Smirnov test was performed to verify that the sample data were normally distributed. Comparisons between PT0 and PT1 were conducted via paired </span></span><em>t</em> tests, followed by the Student <em>t</em> test for comparisons between groups (α=.05).</div></div><div><h3>Results</h3><div><span>A 27.3 ±15.0% reduction in plaque coverage was observed after the implant restorations had been cleaned intraorally. The efficacy of intraoral ultrasonic cleaning was only 45.4 ±20.6%, with a residual plaque rate of 54.6%. Cleaning without the removal of implant-supported restorations was less effective in participants with a PD >5 mm than in the other participants (</span><em>P</em>=.001). Neither the emergence angle nor the emergence profile had a significant influence on the cleaning effectiveness (<em>P</em>>.05).</div></div><div><h3>Conclusions</h3><div>Biofilms at the abutment−prosthesis connection and mucosal and proximal surfaces of the prosthesis may not be effectively cleaned by conventional SPIT. Biofilm reduction is improved by prosthesis removal when the PD is >5 mm.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"134 6","pages":"Pages 2239-2245"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142622709","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}
Pub Date : 2025-12-01DOI: 10.1016/j.prosdent.2024.10.019
Ahmed N. Elsherbini DDS , Ashraf E. Eskandar DDS
Statement of problem
Studies on the significance of intensity on speech production with a tongue prosthesis are lacking, despite this being an important criterion in speech production in patients with total glossectomy.
Purpose
The purpose of this cross-over clinical study was to assess acoustic signal intensity and frequency in patients with total glossectomy rehabilitated with mandibular dentures with 2 different attachment designs for the tongue prosthesis.
Material and methods
Seven participants initially received a mandibular denture with a tongue prosthesis attached using an acrylic resin plate. After a period of 3 months, the dentures were retrieved and modified by replacing the acrylic resin plate with a metal framework as an attachment to the tongue prosthesis to be used for another 3 months with no washout period. The intensity and acoustic energy frequency of acoustic signals were recorded and analyzed for both denture designs at insertion, after 1 month, and after 3 months using 2-way repeated ANOVA (α=.01). Patient satisfaction was evaluated at the end of the follow-up period using a questionnaire. Participants were asked about comfort, phonation, and deglutition ability. The McNemar test was used for all parameters (α=.01).
Results
Intensity mean ±standard deviation values for the acrylic resin plate group were 21.56 ±0.54 at insertion, 19.23 ±0.25 at 1 month, and 15.46 ±0.21 at 3 months. For the metal framework group, they were 19.05 ±0.19 at insertion, 16.88 ±0.16 at 1 month, and 13.98 ±0.09 at 3 months. The differences were statistically significant (P<.01).
Conclusions
The intensity of the sound (loudness) decreased in the metal framework group, which affects the ability to increase volume in a noisy environment. Participants showed higher satisfaction with the comfort of the metal framework design compared with the acrylic resin plate design. However, participants showed higher satisfaction with the deglutition ability while using the acrylic resin plate when compared with the metal framework.
{"title":"Acoustic signal intensity analysis in patients with dysphonia rehabilitated with two different designs for tongue prostheses: A cross-over study","authors":"Ahmed N. Elsherbini DDS , Ashraf E. Eskandar DDS","doi":"10.1016/j.prosdent.2024.10.019","DOIUrl":"10.1016/j.prosdent.2024.10.019","url":null,"abstract":"<div><h3>Statement of problem</h3><div>Studies on the significance of intensity on speech production with a tongue<span> prosthesis are lacking, despite this being an important criterion in speech production in patients with total glossectomy.</span></div></div><div><h3>Purpose</h3><div>The purpose of this cross-over clinical study was to assess acoustic signal intensity and frequency in patients with total glossectomy rehabilitated with mandibular dentures with 2 different attachment designs for the tongue prosthesis.</div></div><div><h3>Material and methods</h3><div><span>Seven participants initially received a mandibular denture with a tongue prosthesis attached using an acrylic resin plate. After a period of 3 months, the dentures were retrieved and modified by replacing the acrylic resin plate with a metal framework as an attachment to the tongue prosthesis to be used for another 3 months with no washout period. The intensity and acoustic energy frequency of acoustic signals were recorded and analyzed for both </span>denture designs<span> at insertion, after 1 month, and after 3 months using 2-way repeated ANOVA (α=.01). Patient satisfaction was evaluated at the end of the follow-up period using a questionnaire. Participants were asked about comfort, phonation<span>, and deglutition ability. The McNemar test was used for all parameters (α=.01).</span></span></div></div><div><h3>Results</h3><div>Intensity mean ±standard deviation values for the acrylic resin plate group were 21.56 ±0.54 at insertion, 19.23 ±0.25 at 1 month, and 15.46 ±0.21 at 3 months. For the metal framework group, they were 19.05 ±0.19 at insertion, 16.88 ±0.16 at 1 month, and 13.98 ±0.09 at 3 months. The differences were statistically significant (<em>P</em><.01).</div></div><div><h3>Conclusions</h3><div>The intensity of the sound (loudness) decreased in the metal framework group, which affects the ability to increase volume in a noisy environment. Participants showed higher satisfaction with the comfort of the metal framework design compared with the acrylic resin plate design. However, participants showed higher satisfaction with the deglutition ability while using the acrylic resin plate when compared with the metal framework.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"134 6","pages":"Pages 2630-2635"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142682170","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}
Pub Date : 2025-12-01DOI: 10.1016/j.prosdent.2024.09.003
Jie Shen PhD , Nasrin Taheri-Nassaj PhD , Cherilyn G. Sheets DDS , James C. Earthman PhD
Statement of problem
Quantitative percussion diagnostics (QPD) has been devised to nondestructively evaluate the mechanical integrity of human teeth and implants, the mechanical integrity of the underlying bone, and the presence of cracks, but the mechanism is not clearly understood.
Purpose
The purpose of this study is to better understand the dynamic behavior of a tooth under conditions consistent with QPD by focusing on physiologically accurate 3D finite element models of a human mandibular second molar with surrounding tissues.
Material and methods
Finite element analysis (FEA) was used to study the force response of dental structures measured by the sensor in a QPD handpiece. A defect-free (intact) and a cracked tooth model containing a vertical crack involving enamel, dentin, periodontal ligament, bone, and the QPD percussion rod were used for this purpose. Different crack gap spaces were studied for comparison. The FEA model was validated with clinical QPD data for a second mandibular molar containing a vertical crack that subsequently had to be extracted. The location and size of the vertical crack was determined once the tooth was extracted.
Results
The present FEA results exhibited features consistent with those of corresponding clinical data, thus verifying the model. An examination of the relative acceleration of the crack faces with respect to each other revealed that an oscillation between the crack surfaces results in secondary peaks in the QPD energy return response compared with that of an intact tooth.
Conclusions
The present FEA modeling can generate simulated QPD results that exhibit established distinguishing characteristics in clinical QPD data for intact and cracked second mandibular molars. The model results also give insight into how QPD detects the presence of cracks and show that the oscillation of crack surfaces can produce the multipeak QPD results for a cracked molar observed clinically.
{"title":"Finite element modeling of an intact and cracked mandibular second molar under quantitative percussion diagnostics loading","authors":"Jie Shen PhD , Nasrin Taheri-Nassaj PhD , Cherilyn G. Sheets DDS , James C. Earthman PhD","doi":"10.1016/j.prosdent.2024.09.003","DOIUrl":"10.1016/j.prosdent.2024.09.003","url":null,"abstract":"<div><h3>Statement of problem</h3><div>Quantitative percussion diagnostics (QPD) has been devised to nondestructively evaluate the mechanical integrity of human teeth and implants, the mechanical integrity of the underlying bone, and the presence of cracks, but the mechanism is not clearly understood.</div></div><div><h3>Purpose</h3><div><span>The purpose of this study is to better understand the dynamic behavior of a tooth under conditions consistent with QPD by focusing on physiologically accurate 3D finite element models of a human </span>mandibular second molar with surrounding tissues.</div></div><div><h3>Material and methods</h3><div>Finite element analysis<span> (FEA) was used to study the force response of dental structures measured by the sensor in a QPD handpiece. A defect-free (intact) and a cracked tooth model containing a vertical crack involving enamel, dentin, periodontal ligament<span>, bone, and the QPD percussion rod were used for this purpose. Different crack gap spaces were studied for comparison. The FEA model was validated with clinical QPD data for a second mandibular molar containing a vertical crack that subsequently had to be extracted. The location and size of the vertical crack was determined once the tooth was extracted.</span></span></div></div><div><h3>Results</h3><div>The present FEA results exhibited features consistent with those of corresponding clinical data, thus verifying the model. An examination of the relative acceleration of the crack faces with respect to each other revealed that an oscillation between the crack surfaces results in secondary peaks in the QPD energy return response compared with that of an intact tooth.</div></div><div><h3>Conclusions</h3><div>The present FEA modeling can generate simulated QPD results that exhibit established distinguishing characteristics in clinical QPD data for intact and cracked second mandibular molars. The model results also give insight into how QPD detects the presence of cracks and show that the oscillation of crack surfaces can produce the multipeak QPD results for a cracked molar observed clinically.</div></div>","PeriodicalId":16866,"journal":{"name":"Journal of Prosthetic Dentistry","volume":"134 6","pages":"Pages 2368-2374"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142348950","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}
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