Investigation of the clinical, microbiological and immunological aspects of teeth with diagnosis of primary periodontal lesions with secondary endodontic involvement

Abstract

The periodontium and dental pulp are structures closely related due to their embryonic, anatomical and functional origin. Endoperiodontal lesions are characterized by pathological changes with pulp and periodontal involvement in the same tooth. The present study aims to: a) investigate the microbiota of periodontal pockets and root canals of teeth with primary periodontal lesion and secondary endodontic involvement at the different stages of endodontic treatment through Nested PCR and Checkerboard DNA-DNA hybridization; b) monitor the effect of chemo-mechanical preparation and intracanal medication on periodontal pockets and root canals of teeth with primary periodontal lesion and secondary endodontic involvement on endotoxin and lipoteichoic acid levels by the LAL Pyrpgent 5000 turbidimetric method and enzymatic immunosorbent assay - ELISA, respectively; c) monitor levels of pro-inflammatory cytokines (IL-1±, IL-1² and TNF-±) and matrix metalloproteinases (MMP-2, -3, -8, -9 and -13), and substance P by ELISA. The sample will consist of 24 teeth diagnosed with primary periodontal lesion with secondary endodontic involvement, randomly divided into two groups according to the auxiliary chemical substance (AQS) used - chlorhexidine (CHX) gel 2% (n = 12) or sodium hypochlorite (NaOCl) 6% (n = 12) - during the chemo-mechanical preparation (CMP). Samples will be taken from the periodontal pocket and root canal before the CMP using Reciproc® (C1) file; after the CMP (C2); and after calcium hydroxide-based intracanal medication (IMC) (C3). MO will be identified and quantified by molecular method (Nested-PCR and Checkerboard DNA-DNA hybridization). The levels of chemical mediators of inflammation as well as the virulence factors of the microorganisms (IL-1±, IL-1², TNF-± and substance P, LTA) will be measured by Enzyme-Linked immunosorbent Assay (ELISA) and the LPS evaluated by the LAL Pyrogent 5000 turbidimetric method. The patients' pain levels will be further qualitatively measured by visual scale and quantitatively by the electrical test. After processing the samples, the data will be tabulated and statistically analyzed by SPSS for Windows. (AU)