Combined endo-periodontals lesions: microbiological and endotoxic evaluation

Author(s)

Rafaela Casadei Chapola

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2017-02-23

Examining board members

Brenda Paula Figueiredo de Almeida Gomes; Vanessa Bellocchio Berber Haddad; Renato Corrêa Viana Casarin

• Advisor: Brenda Paula Figueiredo de Almeida Gomes

Abstract

The dental pulp and the periodontium are two anatomically distinct but functionally interrelated structures, since both structures have an embryological origin and concomitant formation. Although there is an extensive literature on the microbiota associated with periodontal lesions and on endodontic lesions separately, few studies have focused on the investigation of microorganisms and their virulence factors, such as endotoxins (LPS) of combined endo-periodontal lesions (EPL). LPS, also known as endotoxin, is a structural component of the outer membrane of Gram-negative bacteria responsible for bacterial organization and stability. The pathogenicity of these bacteria in pulpal and periapical inflammatory processes seems to be related to the presence and diversity of LPS. Thus, the objective of this study was to investigate the presence of periodontopathogenic microorganisms in root canals (RC) and periodontal pockets (PP) of teeth with combined endo-periodontal lesions (EPL's); to evaluate the susceptibility of these microorganisms to CMP and to the use of intracanal medication (ICM) at both sites, through two identification methods: microbiological culture (counts of colony forming units, CFU) and Nested-PCR; and to quantify the endotoxic levels in RC and PP before and after the various phases of endodontic treatment. Forteen teeth with pulp necrosis and associated periodontal pocket were selected. After CMP, the teeth were divided into two groups: GI-single session (n = 7); GII- multiple section, using the association of Ca(OH)2 + CHX-gel 2% as ICM (n = 7). Samples were taken at three different moments of endodontic therapy: initial, after CMP and after the use of MIC for 30 days, through pyrogenic/sterile paper points. The susceptibility of these microorganisms to CMP and MIC for 30 days was performed through the count of CFU. The microorganisms were identified using the molecular technique of Nested-PCR, with the use of species-specific primers to Treponema denticola, Treponema socranskii, Gemella morbillorum, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia, Prevotella tannerae, Prevotella nigrescens, Fusobacterium nucleatum, Filifactor alocis, Parvimonas micra. The Limilus Amebocyte Lysate (LAL) test was performed for endotoxin quantification. The results showed that the CFU were higher in PP compared to RC, in all phases of endodontic treatment. There was a statistically significant reduction, comparing the initial and post CMP samples, and comparing the samples after CMP and after 30 days of MIC, in both sites (p <0.05). The most commonly detected microorganisms in the RC were Prevotella tannerae in 71.42% (10/14) before CMP; after CMP, Tannerella forsythia, Prevotella Tannerae, Prevotella nigrescens and Fusobacterium nucleatum in 42.8% (6/14); after MIC Treponema denticola, Aggregatibacter actinomycetemcomitans, Porphyromonas endodontalis, Prevotella nigrescens and Fusobacterium nucleatum in 57.1% (4/7. The microorganisms most frequently found in the PP were Treponema denticola and Parvimonas micra 92.8% (13/14) in the initial samples; Fusobacterium nucleatum 78.57% (11/14) after PQM; and Tannerella forsythia and Porphyromonas gingivalis in 100% (7/7) in the samples after MIC. No statistically significant relationship was found between the presence of microorganisms in the different phases of the endodontic treatment, in the PP and RC (p <0.05). Statistically positive associations were detected between the presence of endodontic and periodontal signs and symptoms and some bacterial species, as well as between species. The concentration of endotoxins in the initial samples in the PP was high (648,11 EU / mL), but after the CMP (109.65 EU / mL) and intracanal dressing use (36.5 EU / mL) there were statistically significant reductions (P <0.05). In RC, the initial endotoxic concentration was 15.6 EU / mL; after CMP 0.19 EU / mL; and after intracanal dressing 0.06 EU / mL, these reductions were statistically significant (p <0.05). No statistically significant association was detected between the presence of LPS and clinical aspects, in the RC and PP. It was concluded that in the RC and PP of the teeth with pulp necrosis and associated periodontal pockets were contaminated by potent periodontopathogens. The CMP and MIC for 30 days were highly effective in reducing endotoxic levels in the RC and associated PP. Although microbial reduction in PP after the use of MIC was not significant, its use was very effective in reducing endotoxic levels (AU)

• FAPESP's process: 14/27365-1 - Combined endo-periodontal lesions: microbiological and endotoxic evaluation
• Grantee: Rafaela Casadei Chapola
• Support Opportunities: Scholarships in Brazil - Master