Effect of EDTA at different pHs and the calcium hydroxide paste on the antimicrobial action and biofilm dissolution

• Grant number: 17/21734-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2018
• End date: September 30, 2019
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Marco Antonio Hungaro Duarte
• Grantee: Bruna Rossetti da Silva
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

The aim of this study is to analyze 17% ethylenediaminetetraacetic acid (EDTA) in different pHs (3, 7 and 10), associated or not with post-irrigation using 1% sodium hypochlorite, and previous use of calcium hydroxide paste in antimicrobial action and E. faecalis biofilm dissolution. Material and Methods: In vitro biofilm of Enterococcus faecalis will be induced for 21 days on 50 blocks of bovine teeth. After that, the blocks will be divided into 10 groups (n = 5). In the groups G1, G2, G3, the samples will be treated with 17% EDTA with the following pHs: 3, 7 and 10 for 3 minutes. In the groups G4, G5 and G6, the blocks will be irrigated with EDTA at different pHs for 3 minutes, followed by irrigation with sodium hypochlorite (NaOCl1%) for 5 minutes. The samples from groups G7, G8 and G9 will initially be treated with calcium hydroxide (Calen PMCC) for 7 days, then the blocks will be irrigated with EDTA using the different pHs for 3 minutes and, subsequently with NaOCl 1% (5 minutes) for paste removal. In group 10, after use of the antimicrobial medication for 7 days, the blocks will be irrigated with 1% sodium hypochlorite for 5 minutes. By using confocal microscopy, images of the samples will be captured for the measurement of viable bacteria cells by the Bioimage program, after using the dye LIVE/DEAD. In addition, biovolume biofilm will be obtained. (AU)