Abstract This study aimed to compare the mechanical properties of various occlusal plate materials by analyzing surface roughness, Knoop microhardness, flexural strength, and modulus of elasticity. Fifty samples were prepared and classified as SC (self-curing acrylic resin), WB (heat-cured acrylic resin), ME (acrylic resin polymerized by microwave energy), P (resin print), and M (polymethylmethacrylate polymer block for computer-aided design/computer-aided manufacturing). The data were analyzed using a one-way analysis of variance and Tukey’s honestly significant difference test. Surface roughness was the same in all groups. The surface hardness of group M was statistically superior. The samples from groups P and M had higher flexural strength than other samples. The modulus of elasticity of group SC was statistically lower than that of other groups. The mechanical properties of the materials used to make the occlusal plates differed, and group M achieved the best results in all analyses. Therefore, clinicians must consider the material used to manufacture long-lasting and efficient occlusal splints.

Abstract Temporomandibular dysfunction (TMD), anxiety, and depression are disorders that, due to the current lifestyle, are affecting an increasing portion of the population. Investigating the prevalence of the symptoms of these disorders during the quarantine due to the coronavirus 2019 pandemic (COVID-19) is important to outline clinical strategies for patient care. Objective: This study assessed the prevalence of TMD symptoms, anxiety, depression, and oral behaviors and their associations during the social isolation due to COVID-19. Methodology: Questionnaires were used to assess TMD symptoms in accordance with the Diagnostic Criteria for Temporomandibular Disorders: clinical protocol and assessment instruments, a questionnaire to verify oral behaviors and Hospital Anxiety and Depression Scale to assess symptoms of anxiety and depression in students of dentistry at the Faculty of Health Sciences of the University of Brasília in May 2020. Qualitative data were subjected to descriptive statistics and chi-squared analysis (p<0.05). The relationship between quantitative and qualitative data was evaluated using Spearman's rho correlation (p<0.05). Results: There was a high prevalence of TMD symptoms, anxiety, and depression in the participants, resulting in association between gender and anxiety symptoms (p=0.029). There was a positive correlation between oral behaviors and TMD symptoms (r=0.364; p<0.001), between oral behaviors and anxiety symptoms (r=0.312; p=0.001), and between oral behaviors and symptoms of depression (r=0.216; p=0.021). Conclusion: Social isolation due to the COVID-19 pandemic has an impact on the prevalence of TMD symptoms, anxiety, and depression.

Purpose: The aim of this study was to evaluate the effect of a surface treatment with Sofreliner primer on tensile bond strength of a resin-based soft liner (Coe-Soft) bonded to a polymethylmethacrylate (PMMA) resin before and after accelerated aging simulated by a thermocycling machine. Material and Methods: One hundred and twenty rectangular specimens of PMMA resin were fabricated with 10 × 10 mm² of cross-section and 40 mm of height. The resin-based soft liner was positioned between two PMMA resin specimens. The specimens were divided randomly into 6 groups (n = 10) according to the surface treatment and accelerated aging cycles (0, 500 and 1000). After accelerated aging, specimens were submitted to tensile bond strength test. The fractures were classified as adhesive, cohesive or both. Results: Most failures were classified as cohesive (p = 0.025) and there was an increase on the mean values of tensile bond strength for group with primer application regardless the cycles of accelerated aging, and also an increase along thermocycling periods. The scanning electronic microscopy was used to illustrate the types of failures and the effect of primer application on PMMA acrylic resin surface. Conclusion: The primer application associated with resin-based soft liners is clinically viable, once this treatment strategy provides a reliable adhesion.