No abstract

O processo carioso pode provocar alterações morfológicas e funcionais, sendo o Streptoccus muttans um dos microrganismos mais comuns devido a sua capacidade de aderência sobre a superfície da estrutura dentária. Os danos causados podem ser recuperados a partir de técnicas restauradoras do elemento dental. Estudos têm demostrado que o uso de protocolos de polimento e acabamento torna a superfície mais lisa, dificultando a adesão microbiana e, consequentemente, recidivas. Logo, o objetivo deste estudo foi avaliar in vitro, a influência do uso das tiras Sof-Lex na adesão bacteriana aos materiais restauradores Z100 e Z250. Para realização do estudo, foram confeccionados 24 espécimes (N=6), que foram divididos em dois grupos com protocolos de polimento (G1 e G3) e dois sem protocolos de polimento (G2 e G4), os grupos permaneceram em frascos contendo meio de cultura inoculado com Streptococcus muttans para a adesão microbiana. Após o período de incubação, os espécimes foram trocados de frasco contendo solução salina, agitados em vórtex, diluídos sequencialmente e plaqueados em meio de cultura para realização da contagem das UFC. Os dados dos diferentes grupos foram submetidos ao teste Kruskal-Wallis One Way Analysis of Variance e o nível de significância foi de 5%. Os resultados mostram que não houve diferença estatística entre os tipos de resinas avaliados, porém ambas apresentaram menor aderência microbiana quando submetidas ao polimento. Diante dos resultados, podemos concluir que o polimento das resinas compostas reduz o risco de formação do biofilme sobre a superfície do material.   IN VITRO EVALUATION OF THE INFLUENCE OF POLISHING PROTOCOLS ON BACTERIAL ADHESION ON COMPOSITE RESIN   ABSTRACT The carious disease process may cause morphological and functional alterations, and Streptoccus muttans is one of the most common microorganisms due to its capacity of adherence on the surface of the dental structure. The damage caused may be repaired with restorative techniques for the dental element. Studies have shown that the use of polishing and finishing protocols improves the smoothness of the surface, hindering microbial adhesion and, consequently, relapse. Therefore, the aim of this study was to evaluate in vitro, the influence of the use of Sof-Lex strips on bacterial adhesion to Z100 and Z250 restorative materials. To conduct the study, 24 specimens (N=6) were made and divided into two groups with polishing protocols (G1 and G3) and two with non-polishing protocols (G2 and G4), the groups remained in bottles containing culture medium inoculated with Streptococcus muttans for microbial adhesion. After the incubation period, the specimens were changed in bottles containing saline solution, vortexed, sequentially diluted, and plated in culture medium for CFU counting. The data from the different groups were submitted to the Kruskal-Wallis One Way Analysis of Variance test and the significance level was 5%. The results obtained demonstrated that there was no statistical difference between the types of resins evaluated, although both of them presented less microbial adherence when submitted to polishing. Given the results, we can conclude that the polishing of composite resins reduces the risk of biofilm formation on the surface of the material.   Keywords: Operative Dentistry. Dental Polishing. Composite resins. Streptococcus mutans.

The aim of the study was to evaluate the biomechanical behavior, through photoelastic (PA) and strain gauge analysis (SA), of single crown implant-supported prosthesis with different implant connections (external hexagon (EH), Morse taper (MT), internal Morse hexagon (IMH), Morse taper hexagon (MTH), and frictional Morse taper (FMT)) and different occlusal loads (axial and oblique (45°)). The data were submitted to ANOVA and Tukey's test (α = 0,05). By photoelasticity, regarding axial load, EH produced more high-intensity fringes (2.784 kPa) than the other connections. For the oblique load, all connections generated the same high-intensity fringes (3.480 kPa), except by MT group, that produced the same amount as axial load (2.088 kPa). For the strain gauge analysis, for the axial load, EH showed the highest microstrains value (158,76) and lowets for MT (59,88). For all other groups, oblique load produced higher microstrains values than axial load. For the oblique load, MT showed the lowest microstrains value (88.79), followed by FMT (391,43), EH (468,47) and IMH (507,65). MTH presented the highest value (621,25) compared to all groups (P <0.05). When comparing both loads of the same connection system, only MT showed similar values (P <0.05). It was possible to conclude that the different connection systems tested directly influenced the stress distribution at both loads. The implants with internal connection present less stress distribution when submitted to axial load than the EH group. However, when the oblique load was applied, all connections presented higher values of stress distribution, except for the MT group.