Evaluation of the internal anatomy of paramolar tubercles using cone-beam computed tomography.

PURPOSE: To evaluate the internal anatomy of paramolar tubercles (PTs) on molars, determine the existence of root canals in these structures that either communicate with or are isolated from the main root canals of teeth, and analyze the prevalence of root fusion and a C-shaped canal configuration using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Twenty-six molars with PTs from the study group and 664 molars without PTs from the control group were evaluated using CBCT. The locations and sizes of tubercles were noted. The existence of root canals in PTs was detected. All teeth were evaluated according to the presence or absence of root fusion and a C-shaped canal configuration. Statistical analyses were performed with Pearson Chi square and Fisher's exact tests (p < 0.05). RESULTS: Eleven (42.3%) PTs with their own canals communicated with the main root canals of teeth, and 10 of 11 PTs (90.9%) were larger than 4 mm in size. No PT possessed its own canal independent from the other canals. Teeth with PTs tended to have more root fusions than teeth without PTs. A statistically significant correlation was observed between PTs and the C-shaped canal configuration (p < 0.01). Maxillary second molars with PTs were the major teeth showing variations in the internal morphology. CONCLUSIONS: PTs are an uncommon anatomical variation that is specific to the coronal and radicular morphology. Therefore, clinicians should be aware of its unpredictable and complex internal anatomy, particularly in cases requiring endodontic treatment. CBCT is recommended for teeth with PTs, particularly maxillary second molars, to improve the prognosis of the teeth.

Effect of APF gel on micromorphology of resin modified glass-ionomer cements and flowable compomers.

The purpose of this study was to evaluate the surface micromorphology of resin modified glass-ionomer cements and flowable compomers. In the study two resin modified glass-ionomers and two flowable compomers were used to prepare standardized 20 cylinderic samples. Samples were divided into four groups. Surface treatments with APF gel for experimental groups (group B,C,D) or distilled water as a control (group A) were performed four times. In group B, only APF gel was applied. In group C, after the APF gel application, the samples were immersed into the demineralizing and remineralizing solutions. In group D, before the APF gel application, the buffer solution was applied. The examinations of the surface micromorphology of the materials were made by using scanning electron microscope (SEM). Results showed that in group B all of the materials except Compoglass Flow, and in group C all of the materials showed erratic behaviours. In group D, severe erratic effect (score 2) was obtained on the surfaces of Vivaglassliner and Dyract Flow, and for the others score 1 signals were found. The moderate degradation was obtained by applying of only APF gel on the surfaces of both material groups. The addition of pH circulation caused increasing of micromorphologic changes on the surfaces of all materials. The effect of application of buffer solution on the surfaces before APF gel changed according to the materials. If acidulated fluoride gel is preferred for prophylactic therapy in patients' mouth, for the success, either buffer or neutral fluoride have to be applied on the restored teeth by resin based materials before acidulated fluoride application.

[Influence of acute hemorrhage on erythrodieresis]. / Vliianie ostroi krovopoteri na sostoianie kletochnykh mekhanizmov érytrodiereza u krys.

Influence of acute hemorrhage on peritoneal and splenic macrophages function and NO production was studied. Interaction of peritoneal and splenic macrophages with autologous erythrocytes was examined the day after the hemorrhage. Concentration of nitrate ions: the stable metabolites of nitric oxide, was measured in peritoneal lavage, splenic cells suspension, blood, as well as in supernatant of peritoneal and splenic macrophages before and after hemorrhage. The data obtained suggest that splenic macrophages of intact rats are more active than peritoneal ones. After hemorrhage peritoneal macrophages activity increases, whereas splenic macrophages remain unchanged. Concentration of nitrate ions is significantly reduced after hemorrhage.