This study aimed to investigate the failure behavior of 3 mol.% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) prosthetic crowns air-abraded with aluminum oxide (AO) particles of different sizes. Ninety ceramic premolar crowns were produced with 3Y-TZP frameworks veneered with porcelain. Crowns were randomly divided into three groups, according to the size of the air abrasion AO particles (n = 30): (GC) untreated (control); (G53) 53 µm; (G125) 125 µm. Air abrasion was performed with 0.25 mpa pressure, 10-mm distance, for 10 s. Crowns were adhesively cemented to dentin analog abutments. Specimens were loaded in compression to failure, in 37oC distilled water, using a universal testing machine (n = 30). Fractographic analysis was performed using a stereomicroscope and SEM. The roughness of the crown’s inner surface was evaluated using an optical profilometer (n = 10). Fracture load data were statistically analyzed with Weibull analysis and roughness data with Kruskal-Wallis (α = 0.05). GC had the lowest characteristic fracture load (L0), while G53 and G125 had higher and statistically similar L0 values. The Weibull modulus (m) was similar among groups. The failure modes observed were catastrophic failure and porcelain chipping. There were no differences between the roughness parameters for the experimental groups (p > 0.05). The size of the AO particles did not affect the fracture load and failure mode of 3Y-TZP crowns. Air abrasion with 53 µm and 125 µm particles resulted in a higher fracture load of ceramic crowns than the untreated group while maintaining their reliability and surface characteristics.

The aims of this study were to evaluate the knowledge of dentists on the diagnosis and treatment of clinical situations of dental trauma and the impact of an orientation activity in the form of a lecture on the training process of professionals. The assessment instrument was a questionnaire that contained professional information and different clinical cases of dental trauma for dentists to answer. Data were collected in two stages, before and after the lecture. For statistical analysis, the G test was used, with a 5% significance level. Most professionals were general practitioners (71.4%), and most of them had experience with dental trauma (75.5%). However, when the statistical analysis was carried out, only the conduct before a tooth with pulp exposure > 2mm with incomplete rhizogenesis and management after immediate re-implantation of avulsed tooth with complete rhizogenesis, demonstrated positive results with statistically significant differences. In view of this, we concluded that the professionals had satisfactory knowledge, with reservations for more complex cases.However, orientation activity did not contribute to the improvement in clinical decisions.