Evaluation of the antimicrobial activity, quality of removal and influence on the bond strength of calcium hydroxide pastes associated with different substances

• Ano de defesa: 2019
• Autor(a) principal: Piazza, Bruno
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Calcium hydroxide; Hidróxido de cálcio; Microbiologia; Microbiology; Push-out; Ultrasound; Ultrassom
• Link de acesso: http://www.teses.usp.br/teses/disponiveis/25/25147/tde-25112019-155653/

Calcium hydroxide is commonly used in endodontics because of its physicchemical properties. However new associations to the calcium hydroxide paste are proposed due to the bacterial modification and resistance acquired. The aim of the present study was to evaluate the association of calcium hydroxide paste with diclofenac sodium, ibuprofen and ciprofloxacin hydrochloride, evaluating the removal of these medications from dentin walls, interference with adhesion of endodontic cement and diffusion through dentinal tubules on bacterial biofilms extra radicular. The paste removal test used 80 bovine teeth later cleaved in the longitudinal direction (Crown-apex) and remounted in muffle for the insertion of the pastes. The removal was performed seven days after the insertion of the medications with the aid of an ultrasound coupled to an Irrissonic insert in addition to the conventional removal through the combination of memory instrument, syringe and cannula. The analyzes were performed in scanning electron microscopy (SEM), applying scores for cleaning evaluation. During the mechanical push-out test 50 bovine teeth were divided into groups (n = 10): Negative control (instrumented only), positive control (calcium hydroxide + propylene glycol), diclofenac + calcium hydroxide + propylene glycol, ibuprofen + calcium + propylene glycol, ciprofloxacin hydrochloride + calcium hydroxide + propylene glycol, after filling the channels with the pastes the teeth were stored for 7 days until the time of filling. The teeth were then stored again for 7 days for the total cement prey and sectioned at 2 mm, 4 mm and 6 mm from the foramen and subjected to the push-out test. The failures were evaluated by scanning electron microscopy (SEM) and classified according to their type (adhesive, cohesive and mixed). The antimicrobial test was performed using 26 prepared bovine teeth and removed two blocks of dentin located on the mesial and distal surfaces of each tooth for growth and biofilm culture of Enterococcus faecalis. After cultivation and maturation, the blocks were repositioned and subdivided into two groups containing 13 teeth and 26 blocks of dentin, where only one group received ultrasonic activation after insertion of the pulps and both groups stored in a humid oven at 36ºC for 7 days. The dentin blocks were analyzed using a confocal laser scanning microscope and Live and Dead dye to obtain images of the bacterial cells. After completion of the tests, the data were tabulated and submitted to the D\'agostino and Pearson test to verify normality, which was absent and thus the Kruskal-Wallis tests were applied and for a multiple comparison the Dunn test.