Investigation of endotoxins in primary endodontic infection and evaluation of the periapical inflammatory process before and after the use of root canal medication

Abstract

Endotoxins liberated by Gram-negative bacterial species present a high inflammatory potential against periapical tissues. Previous studies demonstrated that chemomechanical preparation are not effective in the elimination of endotoxins. Indeed, special attention has been given in the search for a root canal medication that is able to neutralize endotoxins, consequentely reducing root canal contents toxicity. The aim of this study is: 1) to investigate the pro-inflammatory profile involved in apical periodontitis from teeth with primary endodontic disease by the levels of IL-1² e TNF-±; correlating their levels with the developmento of clinical and radiographic features; 2) To evaluate the effectiveness of root canal medications - Ca(OH)2 e Ca(OH)2 + CHX-gel 2% - on the reduction of periapical inflammatory process determined by the levels IL-1² e TNF-±; 3) To investigate and monitor the levels of endotoxins present in root canals with primary endodontic infection encountered before and after chemomechanical preparation and after root canal medications - Ca(OH)2 and Ca(OH)2 + CHX-gel 2%. Twenty primarily infected teeth with the presence of apical periodontitis will be selected and subsequently devided into 2 groups according to root canal medication: Ca(OH)2 (n=10) e Ca(OH)2 + CHX-gel 2% (n=10). Endotoxin samples will be collected at three diffent times - before (ES1) and after chemomechanical preparation (ES2) and after 14 days of root canal medication (Es3). Inflammatory samples will be collected at 2 different sampling times - before (Initial sample) (IS1) and after the use of root canal medicaments (final sampling) (IS2). Inflammatory samples will be immediatly stored in plastic tubes containing Tamponated solution + Tween 20 + proteases inhibitors. The levels of pro-inflammatory cytokines and endotoxins will be determined by ELISA assay (Enzyme-Linked Immunosorbent Assay) and LAL- assay method (LAL method, KQCL test). The data obtained in the present study will be typed on a spreadsheet and statistical analyzed by SPSS for Windows and package Statistica 9.0.