Maxillomandibular relationship record methods for computer-engineered complete dentures: a scoping review.

OBJECTIVES: The purpose of this scoping review was to identify different methods employed for recording the maxillomandibular relationship (MMR) for computer-aided designed and manufactured (CAD-CAM) complete dentures (CDs). MATERIALS AND METHODS: This scoping review followed the PRISMA-ScR guidelines and was developed according to Arksey and O'Malley and The Joanna Briggs Institute protocol. The methods were registered on the Open Science Framework (< osf.io/rf4xm> ). The focus question was: "What are the different techniques for recording the maxillomandibular relationship in the digital workflow used in CECDs?" Two investigators searched 3 online databases [MEDLINE (PubMed), Scopus, and Science Direct] independently. The inclusion criteria were clinical studies and reviews that assessed techniques for recording MMR using digital workflow for manufacturing of CECDs. A descriptive analysis was performed considering the study design, manufacturing system, clinical steps, and tools for the determination of MMR, and the difficulty level of procedures. RESULTS: 4779 articles were identified in the electronic search and 10 studies were included for data analysis. The review identified 4 commercially available CAD-CAM denture systems and 3 innovative methods suitable for abbreviating the number of appointments (2 to 4 visits). The trial denture is inherent to the procedure for the Baltic System and 3 innovative techniques. Three techniques (2 innovative and WholeYouNexteeth) demonstrated lower difficulty levels for performing the clinical procedures, regardless of the professional skills. CONCLUSIONS: The commercially available and innovative techniques for the recording of MMR may provide predictability of the treatment. The techniques are effective, however, rely on the learning curve and the patient's clinical condition. CLINICAL RELEVANCE: Recording of the maxillomandibular relationship is paramount for the manufacturing and functionality of complete dentures. Clinicians should be aware of the different tools and techniques described for registering the jaw relationship.

CAD/CAM versus traditional complete dentures: A systematic review and meta-analysis of patient- and clinician-reported outcomes and costs.

STATEMENT OF PROBLEM: Computer-aided design and manufacturing (CAD/CAM) have been increasingly used to enhance the patient and clinician experiences with removable complete dentures (CDs). Yet, evidence from systematic reviews is lacking to validate the clinical significance of these digital prostheses. PURPOSE: The purpose of this systematic review was to compare CAD/CAM CDs with the traditional ones in terms of patient and clinician-reported outcomes, post-insertion adjustment visits and costs. MATERIALS AND METHODS: An electronic search of four databases [Medline (Ovid), Embase, Scopus and Cochrane CENTRAL; last update: May 2022] was performed to retrieve clinical studies comparing CAD/CAM and traditional CDs. Two independent reviewers screened the articles, extracted data (methods and outcomes) and assessed risk of bias of the included studies. The following outcomes underwent meta-analysis (random-effects model): overall patient and clinician satisfaction, oral health-related quality of life (OHRQoL), number of post-insertion adjustment visits, as well as laboratory and total costs. RESULTS: This review included 11 studies. Meta-analysis revealed that CAD/CAM CDs are comparable to the traditional CDs in terms of overall patient satisfaction and OHRQoL. Clinician-reported data depended on the manufacturing technique: whereas milled CDs performed better than traditional CDs in terms of clinician satisfaction and number of adjustments, 3D printed and traditional CDs were similar. Fabrication of CAD/CAM CDs required significantly less laboratory and overall costs than the traditional CDs. CONCLUSIONS: There is some evidence showing that CAD/CAM CDs are at least comparable to traditional CDs. Further well-designed randomized clinical trials are needed to evaluate the performance of specific CAD/CAM approaches for manufacturing CDs, however.

Influence of new complete dentures on the touch perception threshold and quality of life of edentulous patients.

OBJECTIVE: To evaluate the touch perception threshold of the alveolar mucosa and quality of life of edentulous patients before (T0) and 30 days after (T1) the insertion of new complete dentures. BACKGROUND: Touch perception is important so that edentulous patients can detect the position of complete dentures in their mouth. MATERIALS AND METHODS: This study included 32 complete denture wearers with good oral and systemic health and no temporomandibular disorders for at least 5 years. At each time point (T0 and T1), two tests were performed (touch perception threshold and quality-of-life scale). The touch perception threshold (Von Frey or Semmes-Weinstein test) was assessed using nylon monofilaments on the regions of the alveolar mucosa of the maxilla and mandible. The Oral Health Impact Profile for edentulous individuals (OHIP-EDENT) was administered to evaluate oral health-related quality of life. RESULTS: In the maxilla and mandible, the touch perception thresholds for all regions of the alveolar mucosa were significantly lower at T1 than at T0. The OHIP-EDENT mean scores showed that the overall quality of life was significantly better at T1 (3.6) than at T0 (4.7), and a significant improvement in quality of life was observed in all domains of the OHIP-EDENT at T1. For touch perception threshold, effect sizes ranged from 0.4 to 0.8; and for quality of life, effect sizes ranged from 0.4 to 1.0. CONCLUSIONS: New complete dentures reduced the touch perception threshold of the alveolar mucosa of both edentulous arches and improved individuals' quality of life.

Complete denture palatal rugae design impact on satisfaction and quality of life.

OBJECTIVES: To compare the impact of three complete denture palatal rugae designs on participants' satisfaction and oral-health-related quality of life. BACKGROUND: Complete dentures palatal rugea are usually polished to a smooth finish, which can affect the patient's adaptation. Roughening or keeping an opening in the rugae area to replicate the natural sensation of the palatal rugae has been suggested but lacks clinical evidence. METHODS: This randomised crossover trial included participants with complete dentures randomly allocated to six sequences. Each sequence alternated between polished, roughened, and open rugae designs. Participants evaluated general and domain-specific satisfaction (eating, taste, speaking, phonetics, and ease of cleaning) on a 100-mm visual analogue scale. They also completed the Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT) and indicated their preferred design at the end. Repeated-measure ANOVA compared satisfaction, and one-way ANOVA with Tukey's test compared OHIP-EDENT scores. RESULTS: Forty-two participants were randomised. Seven dropped out. General satisfaction ratings were comparable for the polished (Mean = 80.2, SD = 19.7) and roughened designs (Mean = 79.5, SD = 20.2). However, the open design had a significantly lower satisfaction rating (Mean = 41.1, SD = 32.2). OHIP-EDENT scores for the open design (Mean = 44.9, SD = 17.5) were significantly worse than those for the polished (Mean = 36.1, SD = 12.7) and roughened designs (Mean = 36.2, SD = 13.3). Two-thirds of the participants chose the polished design. One-third chose the roughened design; of those, 83% were first-time denture wearers. CONCLUSIONS: Complete dentures with polished and roughened rugae designs were perceived similarly. Both designs could be recommended based on the patient's preference. However, the open design should be avoided due to negative perception.

Clinical parameters that affect performance and patient satisfaction of root-retained overdentures: A systematic review of randomised controlled clinical trials.

OBJECTIVE: To evaluate clinical parameters that affect the performance of root-supported overdentures (ROD) and to identify the possible factors that may affect it. BACKGROUND: ROD still serve as an alternative and successful treatment plan nowadays for partially edentulous patients. Nonetheless, there is not yet conclusive evidence about their clinical evaluation. MATERIALS AND METHODS: A search strategy was developed following a PIO (Population, Intervention, Outcome) framework including an electronic search in the following databases: PubMed, Cochrane Library and Scopus. The systematic search included only randomised controlled clinical trials (RCTs), published until January 2023 in English language and was performed by two independent reviewers. Quality assessment of the included studies was conducted according to the Cochrane Risk of Bias tool. RESULTS: The final selection of studies included 11 RCTs. Clinically relevant variables derived from this search were: Complications, with caries being the most frequently reported, periodontal aspects and bone changes around abutment teeth. Additionally, methods and clinical suggestions for the maintenance of these restorations and patient-related outcomes were assessed. According to the risk of bias assessment, nine studies were considered of high risk, whereas only 2 of low risk. A meta-analysis was not feasible. CONCLUSION: Within the limitations of this systematic review, ROD remain a viable treatment plan, offering better denture stability and bone preservation around abutment teeth and high patient satisfaction. Thorough oral hygiene and regular follow-ups are of utmost importance. Further well-designed RCTs are necessary for firmer conclusions.

Use of digital tools for preclinical training in complete denture: A pilot study.

INTRODUCTION: Advances in CAD-CAM complete dentures open up opportunities in preclinical laboratory education. A cross-over study was conducted to assess the benefit of digital training in custom tray fabrication. Hypotheses were that digital training improved conceptual skill acquisition and that assessment of digital work helps in the discrimination of students' difficulty. MATERIALS AND METHODS: Third-year students were allocated either into group A and took the manual practical classes before the digital ones, or into group B (N = 154). Prior to the sessions, a motor skill test was conducted. The influence on the learning process was evaluated by comparing the groups' results to the manual lab work with a Student's t-test. The effectiveness of the assessment in discriminating manual aptitude and conceptual skill was studied through Spearman's rank coefficient between digital and manual scores in conceptual skill and with a subgroup analysis according to the results of the motor skill test. The level of significance was set up at .05. Students' satisfaction was also assessed with a questionnaire. RESULTS: Students in group B achieved better scores. Spearman's rank coefficient test showed a weak correlation, R = .16. For manual lab work, the most manually skilled students did significantly better. In contrast, for the digital session, the medium manually skilled students did better. More than half of the students (55%) found the manual and digital sessions complementary, without identifying any difference depending on the learning sequence. CONCLUSION: Digital training improved the students' results in the conventional practical exercise. Assessments of the digital and conventional custom trays were complementary in order to distinguish conceptual and motor skills.

Influence of different printing orientations and post-polymerization time on the translucency of three-dimensional (3D) printed denture base resins.

PURPOSE: To evaluate the effect of different printing orientations and post-polymerization time with thermal cycling on the translucency of 3D-printed denture base resins. METHODS: Heat-polymerized (HP) acrylic resin specimens were fabricated and 3D-printed denture base materials (NextDent, ASIGA, FormLabs) were printed with different printing orientations (0, 45, 90 degrees) and subjected to different post-polymerization times (15-, 30-, 60-, and 90-min). All specimens were polished and immersed in distilled water for 1 day at 37°C. CIEDE2000 was used to measure the translucency parameters (TP00) before and after thermal cycling (5000 cycles) recording the color parameters (L*, a*, b*) against a black and white background using a spectrophotometer. k-factors ANOVA followed by post hoc Tukey's test (α = .05) was performed for statistical analysis. RESULTS: The k-factors ANOVA test showed a significant effect of resin material, post-polymerization time, and printing orientation on translucency (p < 0.001). In comparison to HP, all 3D-printed resins showed lower translucency with all post-polymerization times and printing orientation (p < 0.001) except FormLabs resin (p > 0.05). For all 3D-printed resins, the translucency increased, with increasing the post-polymerization time (p < 0.001) and 60- and 90-min showed the highest translucency. For printing orientation, 90 and 45 degrees significantly showed high translucency in comparison to 0 degrees (p < 0.001). FormLabs showed significantly higher translucency when compared with NextDent and ASIGA per respective printing orientation and post-polymerization time. The translucency significantly decreased after thermal cycling for all tested resins (p < 0.001). CONCLUSION: The findings of this study demonstrated that the translucency of 3D-printed resins is influenced by the printing orientation, post-polymerization time, and resin type. As a result, choosing a resin type, and printing orientation, with a longer post-polymerization time should be considered since it may improve the esthetic appearance of the 3D-printed resins.

Additively manufactured CAD-CAM complete dentures with intraoral scanning and cast digitization: A controlled clinical trial.

PURPOSE: To assess, clinically, patient satisfaction of additively manufactured complete dentures with intraoral scanning and hybrid cast digitization in comparison with conventional complete dentures. MATERIALS AND METHODS: Participants who were edentulous in both arches were recruited and received three types of complete dentures (CDs): conventionally manufactured with conventional impression (CC), additively manufactured with intraoral scanning (AMI), and additively manufactured with cast digitization (AMH). Definitive impressions of the edentulous arches were made with medium viscosity polyvinyl siloxane (Hydrorise Monophase; Zhermack, Italy) for the CC group, intraoral scanning (TRIOS 4; 3Shape, Copenhagen, Denmark) for the AMI group, and laboratory scanning of the definitive casts (Ceramill Map400 AMANNGIRRBACH, Pforzheim, Deutschland) for the AMH group. The trial dentures of the CC group were scanned for occlusion registrations of the AMI and AMH groups and were used to guide the designing process (Exocad 3.0 Galway; Exocad GmbH). The AMI and AMH dentures were additively manufactured with a vat-polymerization 3D printer (Sonic XL 4K; phrozen, Taiwan). Patient satisfaction and clinical outcome were assessed with OHIP EDENT, and 14-factor criteria, respectively. Statistical analyses were performed with paired sample t-test and one-way repeated measure ANOVA for satisfaction, Wilcoxon signed rank test for clinical outcome, and Pearson's r (r) for effect size, with α = 0.05. RESULTS: A total of 20 participants were included. Satisfaction had no statistically significant difference within or among the groups (p < 0.105). Within-group comparison between the two arches showed no statistical significance for the clinical outcome except for a significantly higher maxillary AMI score (p = 0.01, r = -0.40 with medium effect size). For among group's comparison; AMI had a significantly lower score than CC for the maxillary and mandibular arches (p = 0.01, r = -0.40, medium effect size, and p = 0.003, r = -0.47, medium effect size), and significantly lower score than the mandibular AMH (p = 0.03, r = -0.47, medium effect size), with significantly lower quality in teeth arrangement and retention domains for the AMI, and teeth arrangement for the AMH, in comparison with CC. CONCLUSIONS: Patient satisfaction with both types of additively manufactured dentures is comparable to conventional dentures. The comparable overall clinical outcomes between hybrid and conventional dentures indicate that additive manufacturing is an acceptable clinical substitute for the conventional methods. However, additively manufactured dentures made with intraoral scanning have lower clinical quality and retention than hybrid and conventional dentures, particularly for the mandibular arch. Teeth arrangement of both additively manufactured dentures is clinically inferior to the conventional denture.

Impact of Compensating Curves on Mastication of Complete Denture Wearers: A Randomised Triple-Blind Clinical Trial.

INTRODUCTION: The application of occlusal concepts in prosthodontics is still under debate.This study assessed the impact of compensating curves on the comminution of complete denture wearers. METHODS: Seven edentulous subjects, aged 64.6 ± 2.0 years, were rehabilitated with new muco-supported complete dentures and tested in two occlusal plane settings: with and without compensating curves. A randomised triple-blind clinical trial was conducted, considering one-week and one-month as adaptation periods for dentures. After each trial, the subjects were crossed over to their respective groups. One-week was also chosen as the washout period, and after that, the subjects were re-examined. The masticatory performance and swallowing threshold were determined while chewing Optocal test food. The multiple sieve method was used for fractionation and granulometry. RESULTS: During the masticatory performance and swallowing threshold estimates, no differences were found between the median particle sizes obtained with the both occlusal plane conditions (P ⟩ 0.05). However, the swallowing threshold improved after one month, resulting in smaller particle sizes. Moreover, the chewing rates for the both test foods were also increased (P ⟨ 0.05). CONCLUSIONS: These findings suggest that the compensating curves did not have an impact on the masticatory function of subjects wearing complete dentures.

DIGITAL FABRICATION OF COMPLETE DENTURES, COMPARED TO CONVENTIONAL METHODS, MAY OFFER A MORE COST-EFFECTIVE APPROACH WITH IMPROVED PATIENT OUTCOMES.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Digitally versus conventionally fabricated complete dentures: A systematic review on cost-efficiency analysis and patient-reported outcome measures (PROMs). Tew, In Meei, Suet Yeo Soo, and Edmond Ho Nang Pow.The Journal of Prosthetic Dentistry (2023). SOURCE OF FUNDING: No fund was received. TYPE OF STUDY/DESIGN: Systematic review.

Treatment effect of implant-supported fixed complete dentures and implant overdentures on patient-reported outcomes: A systematic review and meta-analysis.

OBJECTIVES: To analyze the effect of implant treatment in edentulous patients rehabilitated with implant-supported fixed complete dentures (IFCDs) or implant overdentures (IODs) on dental patient-reported outcomes (dPROs). MATERIALS AND METHODS: In January 2022, Medline, Embase, CINAHL, Cochrane Library, PubMed Central, Web of Science, and ClinicalTrials.gov were screened for prospective clinical studies on completely edentulous patients treated with IFCDs and/or IODs, reporting pre-treatment and follow-up dPROs. Hedges' g effect sizes (ES) with corresponding 95% confidence intervals (CI) were calculated. Afterward, meta-analyses were conducted using random effect models. RESULTS: A total number of 1608 records was initially identified. Of those, 28 studies reporting dPROs from 1457 patients were finally included. The applied dental patient-reported outcome measures (dPROMs) included several versions of the Oral Health Impact Profile (OHIP) or specific items assessing satisfaction with Visual Analogue Scales (VAS). The overall ES was large for rehabilitation with IFCDs (1.68 [CI: 1.15, 2.20]) and IODs (1.26 [CI: 0.99, 1.52]) with no significant difference (p = .165) between the two. Denture stability was the only factor rated significantly higher for IFCDs (ES difference: 2.37 [CI: 0.21, 4.54]; p = .032). Subgroup analyses revealed moderately higher ES for IODs on two implants relative to one implant (ES difference: 0.73 [CI: 0.34, 1.12]; p < .001). CONCLUSIONS: There is a strong positive effect of implant treatment in edentulous patients, independent of the type of prosthetic rehabilitation. In patients seeking high stability, IFCDs may be preferable. In mandibular IODs on a single implant, there was a significantly positive effect of an additional implant on dPROs.

A qualitative analysis of denture wearing experience affecting the quality of life of older adults.

OBJECTIVE: To explore how denture-related experiences affect older adults' quality of life using a qualitative assessment of the Oral Health Impact Profile for Edentulous individuals (OHIP-Edent). MATERIALS AND METHODS: Twenty elderly individuals were interviewed before and 3 months after delivering new complete dentures, using an open-ended interview guide based on the OHIP-Edent. Interviews were audio-recorded and transcribed. Data were open coded and thematically analyzed following a Grounded Theory approach. Findings were integrated and constantly compared to understand the interviewees' difficulties, beliefs, and perceptions. RESULTS: Three interconnected themes were developed: functional and psychosocial impairments, and coping strategies. Even when posed as an open-ended format, the wording of some OHIP-Edent items was confusing while others were not relevant to the respondents. New categories related to speaking, smiling, swallowing, emotional and functional coping emerged from the interviews. Interviewees adapted to chewing and swallowing difficulties through food avoidance, modification of food choice and preparation techniques, and changes in dietary behaviors. CONCLUSIONS: Denture wearing is a daily challenging experience that encompasses various functional and psychosocial aspects and sheds light on the need for addressing the coping strategies employed by patients, as the current OHIP-Edent items may not fully represent other deemed important aspects of the quality of life of individuals who wear dentures. CLINICAL RELEVANCE: Dentists must not solely rely on structured questionnaires to explore the impact of denture wearing and treatment outcomes. Clinicians can use a more holistic approach to comprehend older adults' experiences with dentures including advice about coping mechanisms, food preparation techniques, and meal planning.

The effects of different surface treatments applied to milled PMMA denture base material on repair bond strength.

The high cost of CAD/CAM systems and materials is a severe economic burden. Therefore, repair of CAD/CAM PMMA, selecting appropriate repair materials, and surface modifications are clinically important. This study aims to evaluate the shear bond strength of PMMA repair materials after various surface treatments on CAD/CAM PMMA denture base material. For this purpose, a total of 480 CAD/CAM PMMA denture base test specimens were manufactured. Then all test specimens were divided into 6 groups, and different surface treatments were applied. Group A: sandblasting, Group B: 4% hydro fluoric acid, Group C: tungsten carbide bur, Group D: dichloromethane + methyl methacrylate mixture, Group E: dichloromethane and methyl methacrylate, Group F: no surface treatment. Each group is then divided into 4 different subcategories; repair processes were performed using; heat-cured acrylic resin (n:20), auto-polymerized acrylic resin (n:20), gingiva composite (n:20), and CAD/CAM PMMA tooth material (n:20). After repairs, thermal aging was applied to half of the test specimens in each subcategory. The shear bond strength value was measured with a universal test device. Sandblasting group showed the highest surface roughness value in all test specimens (p < 0.001). Heat-cured acrylic resin with sandblasting exhibited the highest bond strength, while the untreated gingiva composite resin exhibited the lowest value. Thermal aging decreased bond strength in all repair materials (p < 0.001). Among the surface treatment groups, sandblasting with Al2O3 particles exhibited the highest surface roughness value and repair bond strength. The application of organic solvents to the surface increased the surface roughness and repair bond strength. Applying dichloromethane and methyl methacrylate monomer separately is more effective than applying it as a mixture. The ideal bonding among repair materials was obtained with heat-cured acrylic resin.

Willingness to accept or refuse mandibular implant overdenture treatment: A prospective study on edentulous enrolled in a clinical trial.

BACKGROUND: Several complete denture wearers have major complaints and may be benefitted from implant treatment. However, the factors that shape the demand for and utilization of implants need further investigation. OBJECTIVE: The aim was to evaluate edentulous patient's willingness to accept or refuse the offer and provision of implant-retained treatment. METHODS: As part of a clinical trial, edentulous subjects were offered a mandibular overdenture retained by four mini-implants opposing a conventional maxillary denture. Treatment was offered without any financial costs for the patients. Patients' level of interest in receiving treatment was assessed using a 5-point Likert scale, and they were asked to respond to a list of reasons that led to their decision to accept or refuse implants. Those who refused implants received conventional prosthodontic interventions as required, and those who accepted implant treatment underwent surgical planning and implant placement. RESULTS: Of 175 eligible subjects, 147 accepted the offer of treatment and were invited to take part in the study (69.4% women, mean age 67.4 ± 10.0 years). Overall, 111 patients (75.5%) expressed a positive intention to undergo implant treatment at the initial contact. Implant treatment was performed for 56.3% (9/16) of those who answered 'probably yes' about their level of interest in implant treatment on the Likert scale, and 69.6% (64/92) of 'certainly yes' (p < .001). Older subjects were less likely to receive implants (OR = 0.93; p = .036), whilst those with a positive intention towards implants (OR = 3.15; p = .001), those previously treated by the dental team (OR = 7.89; p < .001), and who actively demanded implants (OR = 18.1; p < .001) were more likely to accept treatment. Improved chewing was the most common reason for accepting implants, whilst fear of surgery was the most reported reason for refusal. CONCLUSION: Refusal of implants was high among edentate patients even when financial costs were removed. Patients' initial attitude towards acceptance is a key factor in the demand for and uptake of implant therapy.

Muscle activity between dentate and edentulous patients rehabilitated with dental prostheses: A systematic review.

BACKGROUND: Adequate muscle activity is important for the success of oral rehabilitation: it maintains the integrity of the stomatognathic system and is responsible for chewing movements needed to break, crush and grind food. OBJECTIVE: To compare muscle activity using electromyography (EMG) while clenching or chewing soft and/or hard foods among individuals with natural dentition (ND) and edentulous patients rehabilitated with dental prostheses. METHODS: This review was conducted until March, 2023, and the research question was "Is the muscle activity of edentulous patients rehabilitated with dental prostheses similar to that of dentate individuals?" A search strategy was conducted in PubMed/MEDLINE, The Cochrane Library, Web of Science, Lilacs, Embase and manual journal searches. RESULTS: Ten studies were included in the analysis. Most of them reported that individuals with ND had significant higher muscle activity (clenching or chewing) than complete dentures (CD) users. However, no difference was observed between patients with full mouth implant-supported fixed dental prosthesis (ISFDP) and ND. Additionally, two studies compared patients with mandibular ISFDP with maxillary CD and individuals with ND and found no differences; however, one study concluded that patients with ISFDP with CD (maxillary or mandibular) had lower muscle activity than individuals with ND. Only one study reported a higher muscle activity in patients with full-mouth ISFDP than in individuals with ND. CONCLUSIONS: Bimaxillary CD users had lower muscle activity than individuals with ND. During rehabilitation, the muscle activity of patients with full-mouth ISFDP and mandibular ISFDP with maxillary CD is similar to individuals with ND.

Agreement between self-rated denture condition and clinical examination in older adults.

OBJECTIVES: This study aimed to compare differences between complete denture conditions self-rated by older adult wearers and clinically exanimated by a professional based on standardised aesthetics and functional criteria. MATERIALS AND METHODS: Complete denture clinical examination was based on the functional (stability, retention, occlusion and articulation, vertical dimension of occlusion) and aesthetics criteria. Data on self-rated complete denture conditions were measured using the Patient's Denture Assessment (PDA) questionnaire based on standardised aesthetic and functional criteria (n = 122). Prevalence rates of clinical and self-rated complete denture condition, sensitivity, specificity, positive and negative predictive values, and absolute and relative bias were calculated. RESULTS: The highest sensitivity (66.7% [95% CI 55.3-76.7]) was obtained for aesthetic criterion, whereas occlusion revealed the lowest sensitivity (14.9% [95% CI 6.2-28.3]). Stability had the highest specificity (91.3% [95% CI 72.0-98.9]) and aesthetics the lowest (21.4% [95% CI 8.3-41.0]). Stability also yielded the highest positive predictive value (83.3% [95% CI 51.6-97.9]), and vertical dimension of occlusion the lowest (26.3% [95% CI 9.1-51.2]). The vertical dimension of occlusion yielded the highest negative predictive value (71.2% [95% CI 58.7-81.7]). Self-rated data underestimated the complete denture condition in 6.5% compared with clinical examinations when the aesthetic criterion was excluded from the analysis and 7.6% when added. CONCLUSIONS: Older adult wearers better identified the condition of their complete denture when the aesthetic criterion was excluded from examination. In contrast, considering functional criteria (retention, stability, occlusion and vertical dimension of occlusion), self-rated complete denture conditions underestimated clinical examination. CLINICAL RELEVANCE: Using standardised aesthetic criteria in epidemiological studies for assessing complete denture conditions self-rated by wearers could avoid underestimating or overestimating the information regarding the use or need for dental prostheses.

Tongue training technique for guiding the mandible in establishing horizontal jaw relation in edentulous patients.

BACKGROUND: Edentulous patients have poor neuromuscular proprioception to guide the mandible to the desirable horizontal relation. Horizontal jaw relation is a complex relationship in which variation may occur in vertical, anteroposterior and mediolateral directions. OBJECTIVE: The aim of this study was to train the tongue and bring the mandible to centric relation in geriatric edentulous cases. MATERIALS AND METHODS: Protrude the tongue to the maximum length and retract back to centric relation, move the tongue on the left side beyond the angle of the mouth and bringing back to centric relation, move the tongue on the right and left side beyond the angle of the mouth and bringing back to centric relation, then the tongue should move upwards and touches the marginal tubercle of upper lip and bringing back to centric relation and move the tongue upward and posteriorly to touch the posterior part of the hard palate of the maxilla and swallowing. RESULTS: Edentulous patient can successfully move the mandible in centric relation after training the tongue. CONCLUSION: The present technique is useful for establishment of horizontal jaw relation in edentulous cases using tongue training exercise in Prosthodontic dentistry.

Complications Associated with Metal Resin Fixed Complete Dentures Based on Implant Distribution.

PURPOSE: To compare prevalence and type of complications associated with metal resin fixed complete dentures based on implant distribution. MATERIALS AND METHODS: This retrospective study included data collected for a period of 12 years for patients treated with maxillary and mandibular implant-supported fixed complete dentures at Loma Linda University School of Dentistry. In total, 223 patient's charts were reviewed which included 100 maxillary and 123 mandibular fixed complete dentures. Implant distribution and prevalence of complications associated with each implant-supported fixed complete denture were documented. Tooth delamination, the most common complication associated with fixed complete dentures, was compared between 2 implant distribution groups in each arch. Covariates including age, sex, opposing arch, cantilever occluding units, and number of implants were evaluated to determine their association with tooth delamination. Data and hypotheses were statistically analyzed using descriptive statistics along with logistic regression model. All tests of hypotheses were considered statistically significant at an alpha level of 0.05. RESULTS: In the maxillary arch, some effect of the prevalence of tooth delamination was seen for the group that had implants placed posterior to canine eminence but it was not statistically significant. Denture tooth delamination had the highest prevalence among complications irrespective of implant distribution. Significant denture tooth delamination was seen for patients with opposing fixed complete dentures in comparison to patients with removable opposing arch prostheses. CONCLUSIONS: Implant distribution is not a significant factor related to metal resin fixed complete dentures. Opposing fixed complete dentures have a significantly higher association with denture tooth delamination.

Clinical reproducibility of different centric relation recording techniques in edentulous individuals: An observational cross-sectional study.

PURPOSE: To assess the reproducibility of four different centric relation (CR) recording techniques, and time spent performing each technique in edentulous individuals. MATERIALS AND METHODS: Four techniques were assessed: extraoral gothic arch (EOGA) tracing, intraoral gothic arch (IOGA) tracing, deglutition (D), and frontal manipulation with tongue elevation (FMTE). Twelve subjects participated in the study; four technique records were performed on each volunteer by the same operator. Each record was repeated three times, in the same period of the day, with a 30 min interval between each technique. The reproducibility of each technique was assessed by the tri-dimensional displacement of the position of the condylar housing (mandible condyle) to the wall of the condylar guide (glenoid cavity) in the semi-adjustable articulator (anteroposterior, mediolateral, and superior-inferior). The time spent on each technique was timed in seconds (from the beginning of each technique until the wax occlusion fixation). The analysis of variance (ANOVA) and the Tukey test were performed for anteroposterior displacement (two-way) and for time spent on CT recording techniques (one-way) (α < 0.05). Regarding mediolateral and superior-inferior displacements, the nonparametric Kruskal-Wallis was performed for the comparison between recording methods, whereas the Mann-Whitney test was performed for the comparison between sides (α < 0.05). RESULTS: The factor recording technique interfered with the anteroposterior displacement (ANOVA: α < 0.001; F = 11.396). The technique D (right side: 3.78 ± 0.69 mm; left side: 3.45 ± 0.74 mm) showed a statistically significant difference compared to the other techniques (EOGA: right side: 3.00 ± 0.00 mm; left side: 3.00 ± 0.00 mm; FMTE: right side: 2.81 ± 0.52 mm; left side: 2.82 ± 0.79 mm; IOGA: right side: 2.90 ± 0.65 mm; left side: 3.12 ± 0.44 mm). The time spent on the recording technique influenced the results (ANOVA: α < 0.001; F = 21.118). The IOGA (340.40 ± 163.41 s) and EOGA (285.93 ± 133.84 s) required more time compared to the D (86.00 ± 34.33 s) and FMTE (101.33 ± 36.72 s) techniques. CONCLUSION: Graphic recordings showed better reproducibility and accuracy of the position of the centric relation.

Polymethylmethacrylate Denture Base Layering as a New Approach for the Addition of Antifungal Agents.

PURPOSE: To introduce a new technique, denture base layering, for the addition of titanium dioxide nanoparticles (TiO2 NPs) to polymethylmethacrylate (PMMA) and to investigate the effects of the layering technique on Candida albicans (C. albicans) adhesion and on surface roughness, hardness, translucency, and flexural strength. MATERIALS AND METHODS: In total, 210 heat-polymerized acrylic resin specimens were prepared as discs (15 × 2 mm) for testing C. albicans adhesion (n = 70) and surface roughness, hardness, and translucency (n = 70); and as acrylic plates (65 × 10 × 2.5 mm) for testing flexural strength (n = 70). Specimens were divided into 4 groups: control (n = 30), one-layer (n = 60), double-layer (n = 60), and dotted-layer (n = 60) according to the packing and layering technique. Each group was divided according to the concentration of TiO2 NPs 1% and 2.5% (n = 10). The control group comprised one layer of unmodified resin. The one-layer group comprised one layer of a mixture of PMMA/TiO2 NPs packed conventionally. The double-layer group consisted of two different layers packed in two steps, as follows: unmodified resin first, followed by a continuous thin layer of the PMMA/TiO2 NPs mixture. Similarly, the dotted-layer group consisted of two different layers packed in two steps, as follows: unmodified resin first, followed by a thin layer of the PMMA/TiO2 NPs. However, the second mixture was added in a dotted manner. The direct culture method for C. albicans adhesion before and after ultraviolet light activation, and surface roughness, hardness, translucency, and flexural strength were measured. An analysis of variance and Tukey's post hoc test were used for data analysis (α = 0.05). RESULTS: The addition of TiO2 NPs reduced C. albicans adhesion (p < 0.001). However, no significant difference was found between both concentrations within the same group before and after ultraviolet light activation (p > 0.05), except in the 1% dotted-layer (p = 0.022). Surface roughness and hardness were not affected by the additions of different concentrations of TiO2 NPs (p = 0.905) and (p = 0.059), respectively. Translucency was significantly reduced in all the groups (p < 0.001) except in the 1% dotted-layer (p = 0.332). Flexural strength decreased as the TiO2 NPs concentration increased, with the greatest reduction in strength observed in the one-layer group (p < 0.001). CONCLUSIONS: The double and dotted layering techniques were effective in reducing C. albicans adhesion, without affecting surface roughness, hardness, or flexural strength. However, translucency was reduced in all the groups, except the 1% dotted-layer group.