Conventional and digital maxillary occlusal record for the manufacture of complete-arch implant-supported fixed prostheses: randomized controlled clinical trial.

OBJECTIVES: To evaluate the trueness of the digital maxillary occlusal records in comparison with the conventional records for the fabrication of complete-arch implant-supported fixed prostheses. MATERIALS AND METHODS: This randomized controlled clinical trial followed the recommendations of the CONSORT statement. Twenty participants who used a mandibular interim complete-arch fixed prosthesis and conventional complete maxillary dentures were included in the study. The participants were randomized into two types of maxillary occlusal records: conventional (COR) and digital (DOR) (TRIOS; Shape A/S). After fabricating the prostheses, the distribution and number of occlusal contact points, and the time taken to obtain the maxillary occlusal record and work model were evaluated. Descriptive analysis was used to evaluate the distribution of occlusal contact points. The Wilcoxon test was employed for assessing the number of occlusal contact points, while the Mann-Whitney U test was used for the time taken to obtain the working casts and the maxillary occlusal record and occlusal adjustment times (p < 0.05). RESULTS: There was a similarity in the jaw relation recording methods regarding the distribution of occlusal contact points. There was no difference in the number of occlusal contact points between the anterior (p = 0.439) and posterior (p = 0.227) teeth. No relationship was observed between the distribution and number of occlusal contact points (COR, p = 0.288; DOR, p = 0.183). DOR required less occlusal and clinical adjustment time, on the other hand more laboratory and total workflow time than COR (p < 0.001). CONCLUSION: The DOR may be an option for obtaining the functional space necessary for the assembly of teeth in complete-arch implant-supported fixed prostheses; however, it requires more working time. CLINICAL RELEVANCE: The digital occlusal recording method can be used to assess the interocclusal space for the virtual tooth setup of a complete-arch implant-supported fixed prosthesis.

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.

Fabrication of digital complete dentures guided by facial scanning with a device for recording the maxillomandibular relation: A dental technique.

This article describes a technique for the fabrication of digital complete dentures guided by facial scanning using an innovative device for maxillomandibular relation records. For this, a device was designed and 3-dimensionally (3D) printed to assist in the maxillomandibular record stage. Digital files of the diagnostic casts, jaw relation record, and facial images were superimposed, and the complete denture was virtually planned. Subsequently, trial complete dentures were 3D printed, and a functional and esthetic clinical tooth evaluation was conducted. Then, definitive impressions were made, and definitive complete dentures were obtained. The method of recording the maxillomandibular relation associated with facial scanning in a digital workflow for manufacturing the dentures in a 3-appointment protocol provided better predictability of patient care and reduced clinical and laboratory time than with the conventional denture technique.

Targeting bonding protocols to increase the bond between acrylic resin or 3D printed denture bases and prefabricated or 3D printed denture teeth.

STATEMENT OF PROBLEM: The difference in chemical composition between denture base resin and denture teeth requires the development of bonding protocols that increase the union between the materials. PURPOSE: The purpose of this in vitro study was to evaluate the impact of different bonding protocols on the bond between heat-polymerized and 3-dimensionally (3D) printed acrylic resin denture bases and acrylic resin prefabricated and 3D printed artificial teeth. MATERIAL AND METHODS: Four types of artificial teeth were evaluated: prefabricated acrylic resin (VITA MFT) and 3D printed (Cosmos TEMP, PRIZMA 3D Bio Denture, and PrintaX AA Temp) bonded to 20×24-mm cylinders of heat-polymerized (VipiWave) and 3D printed (Cosmos Denture, PRIZMA 3D Bio Denture, and PrintaX BB Base) denture bases. Three bonding protocols were tested (n=20): mechanical retention with perforation + monomer (PT1), mechanical retention with perforation + airborne-particle abrasion with 50-µm aluminum oxide + monomer (PT2), and mechanical retention with perforation + Palabond (PT3). Half of the specimens in each group received 10 000 thermocycles and were then subjected to the bonding test at a crosshead speed of 1 mm/minute. The failure type was analyzed and scanning electron micrographs made. Additionally, surface roughness (Ra) and wettability (degree) were analyzed (n=15). ANOVA was used to evaluate the effect of the bonding protocol, and the Student t test was applied to compare the experimental groups with the control (α=.05). For type of failure, a descriptive analysis was carried out using absolute and relative frequency. The Kruskal-Wallis test was used to evaluate the surface changes (α=.05). RESULTS: Among the protocols, PT3 with in Yller and PT2 with Prizma had the highest bond strengths of the heat-polymerized denture base and 3D printed teeth (P<.05). When comparing the experimental groups with the control, PT3 and PT2 had greater union with the 3D printed denture base + 3D printed teeth (in Yller), with no difference from the heat-polymerized denture base + prefabricated teeth in acrylic resin. The treatment of the 3D printed tooth surfaces affected the surface roughness of Prizma (P<.001) and wettability (P<.001). CONCLUSIONS: To increase the bond between Yller 3D printed denture base + 3D printed teeth, a bonding protocol including mechanical retention with perforation + Palabond or mechanical retention with perforation + airborne-particle abrasion with aluminum oxide + monomer is indicated. For the other materials tested, further bonding protocols need to be investigated.

Virtual facebow techniques: A scoping review.

STATEMENT OF PROBLEM: Although advances in technology continue to improve the acquisition of patient data and the manufacturing of different oral rehabilitations, the method of transferring clinical information to a virtual environment has not yet been consolidated in the literature. PURPOSE: The purpose of this scoping review was to map the existing literature on different techniques of transferring information from virtual facebows for oral rehabilitation. MATERIAL AND METHODS: This scoping review was structured using a 5-step methodology based on guidelines proposed by Arksey and O'Malley: (1) characterization of the research question, (2) identification of relevant studies, (3) selection of studies, (4) mapping of results, and (5) selection, summary and reporting of the data. The Joanna Briggs Manual for Evidence Synthesis was followed and the review was guided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). The guiding question for the development of this review was, "What virtual facebow techniques are being used to transfer anatomic data to the virtual environment?" RESULTS: A total of 1745 articles were found during the search, and 20 were included in this review. Nineteen of the included articles had positive results with the described techniques of registration and transfer of anatomic references to the virtual environment; however, 1 study indicated that the technique was negative. CONCLUSIONS: Based on the findings, facial scanning, 2-dimensional photographs, and cone beam computed tomography are feasible methods of acquiring extraoral anatomic landmarks. The use of a device that allows the convergence of intraoral and extraoral images by superimposing data was revealed to be a promising option.

Device trueness in passivity and misfit of CAD-CAM frameworks: Conventional versus printed casts.

STATEMENT OF PROBLEM: Obtaining a passive and well-adapted framework is challenging when intraoral scanning edentulous arches with multiple implants. The trueness of the printed casts is unclear. PURPOSE: The purpose of this clinical study was to evaluate the trueness of frameworks made from conventional and printed casts regarding clinical passivity and misfit. MATERIAL AND METHODS: Ten participants with complete mandibular fixed implant-supported interim prostheses retained by 4 implants were included. Each participant had a conventional impression and a digital scan made. The digital scan was made using an innovative device. Both conventional and digital casts were made, and the virtual images were used for milling the digital framework in cobalt chromium alloy. All frameworks were evaluated for passivity and marginal vertical misfit with the single screw test, with 4 attempts consisting of the tightened screw position, a test with all screws tightened, and an interspersed tightening test. The Kruskal-Wallis test was used to evaluate the trueness of the tested device for framework construction through the single screw test on vertical marginal misfit in the conventional and printed groups (α=.008). The Friedman test was used to assess the effect of test type (α=.05), and the Wilcoxon test was used to identify group-to-group differences (α=.017). RESULTS: The absence of space between the framework and the abutments and interferences during its placement, as well as good stability, were observed clinically. In laboratory analysis, greater framework misfits were observed in the printed group compared with the conventional group when the single screw test was applied. Comparing the 3 tests used, the greatest misfits were observed when the framework was screwed onto the printed cast. CONCLUSIONS: The innovative device tested for the intraoral scanning of multiple implants had clinically acceptable accuracy for the construction of passive and adapted frameworks. The conventional cast was more accurate than the printed cast, with lower misfit values, in all tests.

Bond strength between denture lining material and CAD-CAM denture base resin: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: An effective bond between a denture lining material and the denture base resin is necessary for proper function. Regarding the new technologies for manufacturing denture bases, a systematic search of the literature on this topic is lacking. PURPOSE: The purpose of this systematic review and meta-analysis was to evaluate the bond strength between denture lining material and computer-aided design and computer-aided manufacturing (CAD-CAM) denture base resin (milled and 3-dimensionally printed) versus conventional denture base resin. MATERIAL AND METHODS: Electronic databases (PubMed/MEDLINE, Scopus, and Web of Science) were independently searched by 4 researchers for relevant studies published up to April 2023. The population, intervention, comparison, and outcome (PICO) question was: "Comparing conventional and CAD-CAM (milled and 3-dimensionally printed) denture base materials, which promote greater bond strength when associated with denture lining material?" A meta-analysis was performed based on mean ±standard deviation bond strength values between denture base resins and denture lining material with 95% confidence intervals. RESULTS: Five in vitro studies were included. For bond strength, no difference was noted between conventional and milled denture base resin (confidence interval: -0.99 [-2.17 to 0.20]; heterogeneity: t2=0.57; Chi2:4.57; I2=78%; P=.10), and conventional resin had better values compared with those of 3-dimensionally (3D) printed (confidence interval: 3.03 [2.40-3.66]; heterogeneity: t2=0.00; Chi2:0.56; I2=0%; P<.001) when relined with soft materials. The milled denture base resin was better than the conventional (confidence interval: -0.85 [-1.33 to -0.38]; heterogeneity: Chi2:28.87; I2=93%; P<.001), with no difference between 3D printed and conventional (confidence interval: 0.18 [-4.23 to 4.59]; heterogeneity: t2=16.51; Chi2:130.99; I2=98%; P=.94) for hard liners. CONCLUSIONS: The bond strength between resins for milled CAD-CAM denture bases and denture lining material was similar to that of conventional denture base resin, regardless of the consistency of the denture lining material. The bond strength to 3D printed CAD-CAM resin was lower than that of the milled version.

Accuracy and reproducibility of real and virtual occlusal contact points in implant-supported fixed prostheses.

AIM: To evaluate the accuracy and reproducibility of real and virtual occlusal contact points in implant-supported, fixed complete dentures. MATERIALS AND METHODS: The study included 19 participants using mandibular interim complete-arch fixed prosthesis supported by 3 or 4 implants as opposed to conventional removable complete dentures. At installation, an examiner installed the prostheses and verified the occlusal contact points through 2 methods: recording the real contact points with carbon paper (RC) followed by occlusal photography and intraoral scanning (VC) to record the virtual contact points to obtain a screen print of the software. Then, the two images were randomized to determine the order to be inserted into Microsoft PowerPoint for blind and paired evaluation. The independent variables consisted of the distribution of occlusal contacts points (qualification through pre-defined scores based on the position of the contact points on the surfaces of the teeth) and the reproducibility of the methods by verifying the number of occlusal points. For this, a descriptive analysis was used to evaluate the distribution of occlusal contacts points and the Wilcoxon test for the reproducibility of the occlusal contact points between the methods (p<0.05). RESULTS: The methods had 100% and 73.6% real and virtual occlusal contact points, respectively, which is considered clinically excellent. There was no significant difference regarding the reproducibility of the methods by the number of occlusal contact points (RC: x̅13.32; VC: x̅13.68; p=0.715). CONCLUSION: The use of the tested intraoral scanner can be an easy and fast tool for studying and mapping the occlusion, and storing data for future treatment, with the conventional method being the preferred method for performing the occlusal adjustment.

Physical, Mechanical, and Anti-Biofilm Formation Properties of CAD-CAM Milled or 3D Printed Denture Base Resins: In Vitro Analysis.

PURPOSE: To investigate surface characteristics (roughness and contact angle), anti-biofilm formation, and mechanical properties (mini-flexural strength) of computer-aided design and computer-aided manufacturing (CAD-CAM) polymethylmethacrylate (PMMA) polymer, and three-dimensional (3D) printed resin for denture base fabrication compared with conventional heat polymerized denture base resins. MATERIALS AND METHODS: A total of 60 discs and 40 rectangular specimens were fabricated from one CAD-CAM (AvaDent), one 3D printed (Cosmos Denture), and two conventional heat polymerized (Lucitone 199 and VipiWave) materials for denture base fabrication. Roughness was determined by Ra value; the contact angle was measured by the sessile drop method. The biofilm formation inhibition behavior was analyzed through Candida albicans adhesion, while mini-flexural strength test was done using a three-point bending test. The data were analyzed using descriptive and analytical statistics (α = 0.05). RESULTS: The CAD-CAM PMMA group showed the lowest C. albicans adhesion (log CFU/mL: 3.74 ± 0.57) and highest mini-flexural strength mean (114.96 ± 16.23 MPa). 3D printed specimens presented the highest surface roughness (Ra: 0.317 ± 0.151 µm) and lowest mini-flexural strength values (57.23 ± 9.07 MPa). However, there was no statistical difference between CAD-CAM PMMA and conventional groups for roughness, contact angle, and mini-flexural strength. CONCLUSIONS: CAD-CAM milled materials present surface and mechanical properties similar to conventional resins and show improved behavior in preventing C. albicans adhesion. Nevertheless, 3D printed resins present decreased mini-flexural strength.

Effects of long-term cinnamaldehyde immersion on the surface roughness and color of heat-polymerized denture base resin.

STATEMENT OF PROBLEM: Cinnamaldehyde has been successfully used for the short-term disinfection of dentures; however, its long-term effects on the surface and color properties of denture base materials remain unknown. PURPOSE: The purpose of this in vitro study was to evaluate the effects of simulated immersion in cinnamaldehyde for up to 5 years on the surface roughness and color parameters of a heat-polymerized denture resin. MATERIAL AND METHODS: Eighty Ø10×5-mm disk-shaped specimens were prepared from microwave heat-polymerized polymethylmethacrylate (PMMA) and immersed in 4 solutions (n=20): TW-tap water (control), SH - 0.5% sodium hypochlorite, PX-alkaline peroxide, and CA-cinnamaldehyde (27 µg/mL). The immersion protocol simulated 104 cycles (3.5 months), 913 cycles (2.5 years), and 1825 immersion cycles (5 years) of a daily immersion cleaning protocol, with immersion times ranging from 10 to 20-minutes. Surface roughness (Sa) and the color parameters of CIELab (L∗ a∗ b∗, ΔEab), CIEDE2000 (ΔE00), and the National Bureau of Standards (NBS) were analyzed at baseline (t=0) and after the immersion cycles. The data were analyzed by 2-way analysis of variance (ANOVA) for repeated measures and the Tukey post hoc test (α=.01). RESULTS: Sa was significantly increased in all groups after 1825 cycles compared with baseline (P<.01), regardless of the solution. Only the time factor significantly affected ΔEab, ΔE00, and NBS parameters, which were below the perceptibility and acceptability thresholds. After a simulated 5-year immersion, the surface roughness and color values of CA-treated specimens were not statistically different from those of the other groups (P>.01). CONCLUSIONS: Cinnamaldehyde solution (27 µg/mL) produced minor effects on the surface roughness and color parameters of a heat-polymerized denture base resin similar to those of 0.5% sodium hypochlorite and alkaline peroxide after a 5-year simulated immersion.

Patient-reported outcome measures and prosthetic events in implant-supported mandibular overdenture patients after immediate versus delayed loading: A systematic review and meta-analysis.

STATEMENT OF PROBLEM: Immediately loaded mandibular overdentures are clinically acceptable treatment options that have gained popularity because their use shortens the treatment duration. However, whether the immediate loading of dental implants can match the prosthetic events, satisfaction, and quality of life of delayed loading is still unclear. PURPOSE: The purpose of this systematic review and meta-analysis was to compare the prosthetic events, satisfaction, and quality of life of immediate versus delayed loading implants in patients rehabilitated with mandibular overdentures. MATERIAL AND METHODS: This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and was registered at The International Prospective Register of Systematic Reviews (PROSPERO) (CRD42021258187). Electronic searches were carried out by 2 independent reviewers in the PubMed/MEDLINE, Cochrane Library, and Web of Science databases up to May 2021. Only randomized clinical trials and prospective studies with at least 10 participants that compared immediate versus delayed loading were selected. A meta-analysis was performed by using the RevMan 5 software program for complications and maintenance outcomes. RESULTS: Seven articles were included in the qualitative analysis, and 4 were included in the quantitative analysis. The meta-analysis demonstrated no significant difference between immediate and delayed loading for prosthetic complications (RR=1.71; 95% CI=0.67-4.37; I2=85%, P=.27) or maintenance (RR=1.92, 95% CI=0.44-8.28; I2=94%, P=.38). CONCLUSIONS: Although the prosthetic complications and maintenance were more likely to favor the delayed loading group, available evidence showed no statistical difference for prosthetic complications and maintenance between immediate loading and delayed loading in mandibular overdentures.

Longitudinal Improvement in Periodontal Parameters between RPD Abutment Teeth with Direct and Indirect Retainers, after Periodontal Therapy.

PURPOSE: To evaluate the effect of basic periodontal treatment on clinical periodontal parameters associated with abutment teeth of patients with mandibular Kennedy class I removable partial dentures (RPD) 18 months after treatment. MATERIALS AND METHODS: Thirty patients with periodontal disease were treated and evaluated according to the following periodontal parameters: visible plaque index (VPI), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), clinical attachment loss (CAL), and keratinized mucosa (KM). These parameters were compared between abutment teeth with direct and indirect retainers at baseline, and after 6 and 18 months. Data were analyzed by Friedman Test and Wilcoxon Test for all variables. RESULTS: Most patients (n = 26; 86.7%) included in the study were female and had a mean age of 61 years (±7.54). Results showed that VPI and BOP decreased over time, and that VPI values were higher in abutment teeth with direct retainers (p = 0.001). There was a reduction in PD after 6 months, which was maintained up to 18 months. In general, abutment teeth with direct retainers had significantly higher values for PD, GR, and CAL (p = 0.029). Data also indicated that the parameters for VPI, BOP, and PD improved; however, abutment teeth with direct retainers presented smaller improvements, compared with abutment teeth with indirect retainers, which presented significant improvements for almost all variables. CONCLUSION: Periodontal treatment and oral hygiene care of patients were adequate for maintenance of adequate periodontal conditions, regardless of the use of prostheses.

Technical Quality of Complete Dentures: Influence on Masticatory Efficiency and Quality of Life.

PURPOSE: To evaluate the effect of the technical quality of conventional complete dentures (CD) on masticatory efficiency and quality of life (QoL) of denture wearers during a 1-year follow-up. MATERIALS AND METHODS: A prospective clinical trial with 32 edentulous patients (mean age of 60.2 years) wearing mandibular and maxillary dentures was conducted. All patients were evaluated wearing their preexisting dentures and after 3, 6, and 12 months postinsertion of new dentures. A reproducible method for objective evaluation of the technical quality of CDs was employed. Masticatory efficiency was evaluated by the colorimetric method using beads as artificial testing food. The oral health impact on patient QoL was measured using the OHIP-EDENT (Oral Health Impact Profile in Edentulous Adults) questionnaire. The nonparametric Wilcoxon test was applied to reveal any differences in technical quality between the preexisting and new dentures. The Friedman test was used to detect differences in masticatory efficiency and oral health impact on QoL. Spearman's correlation was applied to reveal correlation between the variables. RESULTS: Comparing preexisting and new dentures, significant improvement was found in technical quality between the dentures (p < 0.001). There was no statistically significant difference in masticatory efficiency. A significant decrease was found in the total OHIP-EDENT scores after denture replacement. A positive correlation was found between technical quality and OHIP in the new denture wearers (p = 0.011). CONCLUSIONS: According to the results of this study, denture quality significantly improved patients' oral health-related QoL; however, insertion of new dentures did not influence masticatory efficiency.

Reproducibility, Reliability, and Validity of Fuchsin-Based Beads for the Evaluation of Masticatory Performance.

PURPOSE: Rehabilitation of masticatory function is inherent to prosthodontics; however, despite the various techniques for evaluating oral comminution, the methodological suitability of these has not been completely studied. The aim of this study was to determine the reproducibility, reliability, and validity of a test food based on fuchsin beads for masticatory function assessment. MATERIALS AND METHODS: Masticatory performance was evaluated in 20 dentate subjects (mean age, 23.3 years) using two kinds of test foods and methods: fuchsin beads and ultraviolet-visible spectrophotometry, and silicone cubes and multiple sieving as gold standard. Three examiners conducted five masticatory performance trials with each test food. Reproducibility of the results from both test foods was separately assessed using the intraclass correlation coefficient (ICC). Reliability and validity of fuchsin bead data were measured by comparing the average mean of absolute differences and the measurement means, respectively, regarding silicone cube data using the paired Student's t-test (α = 0.05). RESULTS: Intraexaminer and interexaminer ICC for the fuchsin bead values were 0.65 and 0.76 (p < 0.001), respectively; those for the silicone cubes values were 0.93 and 0.91 (p < 0.001), respectively. Reliability revealed intraexaminer (p < 0.001) and interexaminer (p < 0.05) differences between the average means of absolute differences of each test foods. Validity also showed differences between the measurement means of each test food (p < 0.001). CONCLUSIONS: Intra- and interexaminer reproducibility of the test food based on fuchsin beads for evaluation of masticatory performance were good and excellent, respectively; however, the reliability and validity were low, because fuchsin beads do not measure the grinding capacity of masticatory function as silicone cubes do; instead, this test food describes the crushing potential of teeth. Thus, the two kinds of test foods evaluate different properties of masticatory capacity, confirming fushsin beads as a useful tool for this purpose.

Association between prosthetic factors and temporomandibular disorders in complete denture wearers.

OBJECTIVE: The purpose of this study was to investigate the prevalence of temporomandibular disorders (TMD) in denture wearers and the association between prosthetic factors and this condition. BACKGROUND: There is no consensus about the relationship between prosthetic factors and TMD among denture wearers. MATERIALS AND METHODS: The sample was composed of 92 patients wearing both maxillary and mandibular complete dentures. The Research Diagnostic Criteria for TMD (RDC/TMD) were adopted for patient examination. Objective evaluation of denture quality was determined by analysis of retention and stability of mandibular denture, interocclusal distance, articulation and occlusion. Association between denture quality and TMD diagnosis was analysed using chi-square and Fisher's exact tests. RESULTS: 37.4% of the patients presented TMD. Denture quality was not significantly associated with the presence of TMD: mandibular retention (p = 0.466); mandibular stability (p = 0.466); interocclusal distance (p = 0.328); centric relation (p = 0.175); and balanced occlusion (p = 0.56). CONCLUSION: Within the scope of this case-controlled cross-sectional study, no robust association between prosthetic factors and TMD was found.

Bilateral balanced articulation: science or dogma?

For more than a hundred years, it has been supposed that canine guidance should be avoided in conventional complete dentures, since it would result in denture instability. Thus, bilateral balanced articulation has been held by many authors as fundamental for treatment success. However, randomized clinical trials have shown that balanced articulation is not as important as previously thought. The issue about which occlusal concept is the most appropriate for individual needs is clinically and economically relevant for both the dentist and dental technician. Therefore, the purpose of this study is to provide an evidence-based update on complete denture occlusion. Clinical Relevance: The issue about which occlusal concept is the most appropriate for individual needs is clinically and economically relevant.

Impact of using magnifying dental loupes on clinical performance during tooth preparation: A systematic review.

Background: To assess whether using magnification loupes affects tooth preparation working posture performed by undergraduate students and dentistry professionals and whether it influences the quality of the preparation, operator satisfaction and procedure time. Material and Methods: This review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and registered in the International Prospective Register of Systematic Review (CRD42023482377). Electronic searches were conducted in PubMed/Medline, Cochrane Library, Web of Science, and Scopus databases for relevant articles published up to August 2023. Clinical or laboratory studies evaluating cavities or dental preparations performed with and without magnification loupes were considered eligible. The outcomes were operator working posture, dental preparation quality, operator satisfaction, and procedure time. The quality of the studies was evaluated using the JBI Critical Appraisal tools for Quasi-Experimental Studies. Results: The searches retrieved 1493 articles. Based on the eligibility criteria, 11 laboratory studies were included, where 410 undergraduate and graduate dental students conducted dental preparations in 1851 dental specimens. Of the 11 selected studies, 6 evaluated the working posture, 6 assessed the quality of the dental preparations, 5 reported operator satisfaction, and 2 assessed procedure time. The results showed that magnifying loupes significantly improved operator working posture, but did not influence the quality of tooth preparations. Although satisfaction reports about experiences with magnifying loupes were favorable, no significant difference was found. Conclusions: Magnification loupes improved operator working posture. However, clinical studies with more scientific evidence are needed for steady conclusions regarding operator satisfaction and procedural time. Key words:Magnification, dental loupes, tooth preparation, cavity preparation, dental education.

Complications and Patient-Centered Outcomes of an Implant- Supported Single Crown After Immediate and Delayed Loading: A Systematic Review and Meta-analysis.

PURPOSE: To assess the complications, satisfaction, and quality of life of patients rehabilitated with delayed and immediate loading of single crowns. MATERIALS AND METHODS: An electronic search was conducted in PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, and Embase databases up to February 2023. Only prospective studies and randomized and nonrandomized clinical trials comparing immediate and delayed loading were included. For the quantitative analysis, dichotomous and consistent variables were evaluated with a 95% confidence interval. RESULTS: A total of 20 studies were evaluated. No statistically significant difference was observed between protocols: satisfaction (I2: 0%; P = .42), quality of life (I2: 0 %; P = .05), biologic complications (I2: 9%; P = .17), mechanical complications (I2: 58%; P = .84), and survival rate (I2: 0%; P = .38). The subgroup analysis showed significant differences only for marginal bone loss (MBL) when immediate implants were placed in the mandible (I2: 15%; P = .01) and posterior zone (I2: 0%; P = .001). CONCLUSIONS: Complications and patient-centered outcomes for immediate single-implant crowns were comparable to delayed loading. Scientific evidence showed no significant difference between loading protocols for survival rates. Note that several factors could interfere with the complication events, implant failures, and MBL. The subgroup analysis showed that only immediate implants placed in the posterior mandible had a higher and statistically significant mean MBL.

Complete denture rehabilitation for a patient with Parkinson's disease using clinical strategies: A case report.

OBJECTIVE: To present clinical strategies for prosthetic rehabilitation with complete dentures (CDs) of a Parkinson's disease patient. CASE REPORT: An 82-year-old patient sought the Department of Dentistry at UFRN, reporting retention dissatisfaction and hamper to the mandibular CD adaptation. Patient-reported a dry mouth sensation, and exhibited disordered mandibular movements, tremors, and resorbed mandibular ridge. Aiming retention and stability, double molding with zinc enolic oxide impression paste, neutral zone technique, and non-anatomic teeth were proposed as clinical strategies. At delivery, identification and relief in the supercompression areas were performed to facilitate the acceptance and use of the new dentures. CONCLUSION: The strategies promoted patient satisfaction regarding retention, stability, and comfort. This treatment may be considered for the rehabilitation of Parkinson's disease patients, favoring the adaptation process.

Effect of Cantilever Extension on Bone Loss in Mandibular Complete-Arch Implant-Supported Fixed Prostheses with Three and Four Implants.

PURPOSE: To compare the peri-implant bone loss of mandibular complete-arch implant-supported fixed prostheses (FPSs) supported by three and four implants and to correlate with the size of the horizontal and vertical distal cantilever at prosthesis placement (T1) and after 1 year (T2). MATERIALS AND METHODS: A total of 72 external hexagon (EH) type implants were placed in 20 participants. Of these, 24 supported an FPS with three implants (G3I) and 48 with four implants (G4I). The mandibular implants were named 1, 2, 3, and 4 according to their location in the arch, in a clockwise direction. Digital periapical radiographs were taken at times T1 and T2 for analysis and measurement of peri-implant bone loss. The horizontal and vertical distal cantilevers were measured with a digital caliper and correlated with peri-implant bone loss. RESULTS: The survival rate of implants in G3I was 91.66%, and in G4I it was 97.91%. The mean bone loss in G3I was 0.88 ± 0.89 mm, and in G4I it was 0.58 ± 0.78 mm (P = .225). There was no correlation between distal horizontal cantilevers and bone loss in the studied groups, with G3I being -0.25 (P = .197) and G4I -0.22 (P = .129). Larger vertical cantilevers of implants 1 (P = .018), 3 (P =.015), and 4 (P = .045) correlated with greater bone loss in G4I. CONCLUSIONS: The number of implants in an FPS did not influence peri-implant bone loss after 1 year of follow-up. Larger vertical cantilevers influenced greater bone loss in complete-arch implant-supported fixed prostheses supported by four implants.