Relationship between temporomandibular dysfunctions, sleep disorders, and anxiety among dentistry students.

Introduction: This study aimed to evaluate the relationship between temporomandibular dysfunction (TMD), anxiety, and sleep disorder (DS) among dentistry students, relating the periods in which they are enrolled.Methods: The study consisted of 90 students: Group 1: 30 first-period students; Group 2: 30 fifth-period students; Group 3: 30 students from the ninth period. The participants responded to the RDC/TMD, Fletcher & Luckett questionnaires, and the Beck Anxiety Inventory to analyze symptoms of TMD, DS, and anxiety.Results: There was an association between TMD, DS, and the period studied. When related to moderate and severe anxiety, the group that had the highest incidence was Group 1 (first period students).Conclusion: The apprehension for what is new can influence the TMD and DS indices, while the greater concern for academic/professional performance can generate higher levels of anxiety.

Effects of Denture Cleansing Solutions on Different Materials Used for Fabrication of Polymer Attachment Components.

AIMS: To evaluate the effects of different cleansing solutions on the physical-mechanical properties (roughness, surface hardness, and fatigue resistance) of three polymeric materials used to manufacture retentive attachments for overdentures. MATERIALS AND METHODS: The roughness and surface hardness analyses each employed 150 specimens measuring . 9 mm × 2 mm in thickness (polyacetal, polytetrafluoroethylene [PTFE], and polyethylene terephthalate [PET]; n = 50 each). For fatigue resistance analysis, 180 retentive attachments measuring 4 mm × 3 mm in height (n = 60 each) were used. The properties were evaluated before and after immersion in different cleansing solutions: distilled water, alkaline peroxide, 0.5% sodium hypochlorite (NaOCl), and Listerine. After the data distribution was verified using Shapiro-Wilk test, parametric or nonparametric analysis was applied (α = .05). RESULTS: The use of NaOCl caused a significant alteration in the roughness of the materials (P = .011), with a reduction in roughness in polyacetal and an increase in PTFE. The type of solution also influenced the surface hardness (P = .036); with the exception of distilled water, the other solutions promoted increased hardness. During the 24-month period, immersion in water, peroxide, and NaOCl (0.5%) caused increased fatigue resistance (P < .05) of the PET attachments. The immersion protocol resulted in greater fatigue resistance (P < .05) in polyacetal, while PTFE was not affected (P > .05). CONCLUSION: Regarding the physical-mechanical properties evaluated, the polymers PET, polyacetal, and PTFE were susceptible to cleansing solutions.

Bond strength of resin cements to novel materials to intracanal posts applications / Resistência de união de cimentos resinosos a novos materiais para pinos intrarradiculares

Objective: Evaluate the bond strength of resin cements to new materials for application in intraradicular posts. Material and Methods: Five materials were evaluated: fiberglass, PET, polyethylene, polyacetal and PTFE. Two commercial resin cements (Rely X U200 and Rely X Arc) were applied on the test specimens of the materials (9x3mm) and the bonding was evaluated through the shear bond strength test, where the chisel operated with a load of 1kN and a velocity of 0.5mm/min at the cement/material interface. The data were analyzed by the Shapiro-Wilk test, followed by the two-way analysis of variance, performed with the Bonferroni post-test (α=0.05). Results: The glass fiber was statistically different from all evaluated materials (p0.05). Comparing the two cements, a statistical difference was found between Rely X U200 and Arc only for the glass fiber (p=0). Conclusion: PET, polyethylene, polyacetal and PTFE exhibited reduced bond strength compared to the glass fiber (AU)

Objetivo: Avaliar a resistência de união de cimentos resinosos a novos materiais para aplicação em pinos intrarradiculares. Material e método: Foram avaliados cinco materiais: fibra de vidro, PET, polietileno, poliacetal e PTFE. Dois cimentos resinosos comerciais (Rely X U200 e Rely X Arc) foram aplicados sobre os corpos de prova dos materias (9x3mm) e a resistência de união foi avaliada através do teste de cisalhamento, onde o cinzel atuou com carga de 1kN e velocidade de 0,5mm/min na interface cimento/material. Verificada a normalidade dos dados através do teste Shapiro-Wilk, foi realizada a análise de variância de dois fatores com pós-teste de Bonferroni (α=0,05). Resultados: a fibra de vidro foi diferente estatisticamtente de todos os materiais avaliados (p0,05). Comparando-se os dois cimentos, foi encontrada diferença estatística entre o Rely X U200 e Arc apenas para a fibra de vidro (p=0). Conclusão: PET, polietileno, poliacetal e PTFE apresentaram resistência de união reduzida comparando-se à fibra de vidro. (AU)