Endotoxin leakage in root canals instrumented with different solutions and filled with resin-based materials

• Grant number: 05/01448-9
• Support Opportunities: Regular Research Grants
• Start date: December 01, 2005
• End date: November 30, 2007
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Marcelo dos Santos
• Grantee: Marcelo dos Santos
• Host Institution: Faculdade de Odontologia (FO). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The principal aim of the endodontic treatment is the maintenance of the dental function. The treatment of the endodontic disease is based on a combination of chemo-mechanical procedures and the sealing of either the root canal or access cavity with material that prevent re-infection. . For this purpose, studies have been developed in the search of a solid material that enables a better sealing of the root canal. This search resulted in the creation of a new thermoplastic synthetic polymer-based root canal filling material. The chemical substance used during instrumentation can modify the root canal walls, affecting the adhesion to the filling system. The aim of this study is to evaluate the influence of different chemical substances on the sealing ability of resin-based root filling system.It will be used 59 extracted human superior molars. The instrumentation will be performed with a crown down technique with K3 nickel-titanium rotary instruments, varying the chemical substance used during instrumentation and in final irrigation. The group I, will be the control group, and will receive the mechanical instrumentation associated with distilled water. The samples of group II will be instrumented with EndoPTC and sodium hypochlorite and a final irrigation with EDTA-T. The samples of group III will be instrumented with chlorhexidine digluconate in Natrosol gel, and final irrigation with distilled water. The roots of group IV will be instrumented with 1% sodium hypochlorite and final irrigation with the same solution. The roots of groups V and VI will be instrumented with 1% sodium hypochlorite and final irrigation with 1mL of Smear Clear™.All teeth from groups I, II, III, IV and V will be obtured with Real Seal™ system, which is based on Resilon™ cones and a resin-based sealer, with the lateral condensation technique. The roots of group VI will be obtured with thermoplastic Resilon. In this group, Real Seal will be inserted into the canals by Elements Obturation System.For the leakage test, it will be used lyophilized endotoxin extracted from Escherichia coli (lipopolysaccharide). The detection and quantification of endotoxin will be carried out using the Limulus Amebocyte Lysate test (LAL). The data obtained will be tabled and analysed by the appropriated statistical test. (AU)