This study evaluated the fracture resistance of weakened roots restored with glass fiber posts, composite resin cores and complete metal crowns. Thirty maxillary canines were randomly divided into 3 groups of 10 teeth each: teeth without weakened roots (control); teeth with partially weakened roots (PWR) and teeth with and largely weakened roots (LWR). The control group was restored with glass fiber posts and a composite resin core. Teeth in the PWR and LWR groups were flared internally to standardized dimensions in order to simulate root weakness. Thereafter, the roots were partially filled with composite resin and restored in the same way as in the control group. The specimens were exposed to 250,000 cycles in a controlled chewing simulator. All intact specimens were subjected to a static load (N) in a universal testing machine at 45 degrees to the long axis of the tooth until failure. Data were analyzed by one-way ANOVA and Dunnett's test for multiple comparisons (p=0.05). There were statistically significant difference differences (p0.05) between the weakened groups. The results of this study showed that thicker root dentin walls significantly increase the fracture resistance of endodontically treated teeth.

This study evaluated the association of level of anxiety in children with and without sleep bruxism (SB). The study was performed with 84 six- to eigth-years-old children, divided into two groups: with bruxism (BG) and without bruxism (CG). Following the criteria purposed by American Academy of Sleep Medicine (AASM) to determine SB, the presence of tooth wear has been verified through clinical examinations, and the parents have answered a questionnaire about their children’s behavior and habits. Additionally, the State-Trait Anxiety Inventory for Children (STAIC) was applied to parents of the selected patients. Data analysis revealed a statistical significant difference between the groups (Student’s t-test, p = 0.0136). Based on the results, anxiety assessment revealed that children with bruxism have reached higher levels in the STAIC scale than the non-bruxism group. Therefore, it indicates a direct relationship between the presence of anxiety disorder and the onset of bruxism in children.