Impacto de diferentes modalidades de acesso endodôntico na eficácia da instrumentação, redução microbiana, obturação e resistência à fratura em molares inferiores

• Autor(a) principal: Barbosa, Ana Flávia Almeida
• Data de Publicação: 2020
• Outros Autores: [e-mail]
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/18863
• topic: X-ray microtomography; Fracture resistance; Enterococcus faecalis; Conservative access; Microtomografia por raio-X; Resistência à fratura; Enterococcus faecalis; Acesso minimamente invasivo; CIENCIAS DA SAUDE::ODONTOLOGIA

The main goal of conservative endodontic accesses is to preserve as much of the dental structure as possible during endodontic treatment, under the claim of reducing the risk of dental fracture. Nonetheless, the efficacy of such method regarding the decontamination of root canals system is still insufficiently explored in endodontic literature. The present study intends to evaluate the influence of the various types of endodontic accesses in regard to the effectiveness of instrumentation, decrease in intracanal bacterial load, filling and resistance to fracture in mandibular molars. In pursuance of as much, the samples were divided in three groups, representing each type of access thereby performed (n=10 in each group): TEC group - Traditional Endodontic Cavity, CEC group - Conservative Endodontic Cavity, and DDC group - Orifice Directed Dentin Conservation. The teeth were scanned via microcomputed tomography in order to analyze their initial internal anatomy, and allow for their sorting, with the goal of assembling homogenous groups of three specimens. Subsequently, the different types of accesses were performed in accordance to the selected technique. The samples were, then, contaminated with bacterial suspensions of Enterococcus faecalis. Following the three-week period, the initial microbial collection was performed (S1). The teeth were prepared with the instrument Reciproc Blue 25/.08v and another bacterial sample was collected to evaluate the decrease in the intracanal bacterial load (S2). A second instrumentation was performed, using the Reciproc Blue 40./06v instrument, followed by yet another microbial sampling (S3). Another sample was collected, and the teeth were scanned following the final irrigation (S4). Finally, the specimens had their root canals filled and were scanned once more, at which point they underwent cavity restoration and were subjected to fracture resistance tests. The statistical analysis was performed with adjustments of the type I negative binomial regression model as well as the beta regression model with a 0-1 inflation. Testing of instrumentation results, as well as filling and resistance to fracture were performed by means of the ANOVA and Tukey tests. The results showed that the TEC group had a smaller percentage of unprepared surface area in comparison to the CEC group (P<0.05). There has been no discrepancies in the percentage of unprepared surface area between TEC and DDC groups (P>0.05) nor between DDC and TEC groups (P>0.05). No percentual discrepancies were found concerning the removal of dentin, transportation and centering ability among the tested groups (P>0.05). Regarding microbial reduction, following the final irrigation process, no significant variations were present among the groups either (P>0.05). No significant differences were observed among the groups regarding filling voids (P>0.05). Notwithstanding, the TEC group presented a lower volume of filling material within the pulp chamber when compared to CEC and DDC groups (P<0.05). Finally, the resistance to fracture results among all three groups bore no significant difference (P>0.05). In conclusion, the conservative methods did not present any advantage in comparison to the traditional method in any of the parameters subjected to testing, furthermore, conservative methods were associated with higher percentages of unprepared surface area and higher volume of filling material within the pulp chamber.