Microbial distribution in the root canal system after periapical lesion induction using different methods

Abstract

The aim of this study was to evaluate the microbial distribution in the root canal system after periapical lesion induction in dogs' teeth using different methods. Fifty-two root canals were assigned to 4 groups (n=13). Groups I and II: root canals were exposed to the oral cavity for 180 days; groups III and IV: root canals were exposed for 7 days and then the coronal openings were sealed for 53 days. The root apices of groups I and III were perforated, while those of groups II and IV remained intact. After the experimental periods, the animals were euthanized and the anatomic pieces containing the roots were processed and stained with the Brown & Brenn method to assess the presence and distribution of microorganisms. The incidence of microorganisms at different sites of the roots and periapical lesions was analyzed statistically by the chi-square test at 5% significance level. All groups presented microorganisms in the entire root canal system. A larger number of microorganisms was observed on the root canal walls, apical delta and dentinal tubules (p<0.05), followed by cementum and cemental resorption areas. In spite of the different periods of exposure to the oral environment, the methods used for induction of periapical periodontitis yielded similar distribution of microorganisms in the root canal system.

Management of failed periodontal surgical intervention for a furcal lesion with a nonsurgical endodontic approach

“…The apical foramen is believed to be the major pathway through which bacterial byproducts and inflammatory mediators in a diseased pulp are conducted, causing periapical pathosis 2,4. The opposite route is also possible, although unlikely, as the apex can serve as a portal of entry of inflammatory elements from deep periodontal pockets to the pulp 2,5. Lateral or accessory canals can exist anywhere along the root in about 30 - 40% of teeth and contain connective tissue and blood vessels 4,6.…”

Effect of Photodynamic Therapy with Different Formulations of Methylene Blue in Teeth Contaminated by Enterococcus faecalis

“…As a resource to be tested photodynamic therapy has the advantage of not inducing microbial resistance, which is currently very promising for use in areas where there are resistant microorganisms that may lead to unfavorable prognosis [1][2][3][4][5][6].…”

Terapia fotodinâmica antimicrobiana (aPDT) no tratamento de lesões periapicais induzidas experimentalmente, em dentes de cães

“…O LPS estimula a liberação de um grande número de citocinas próinflamatórias, levando à reação inflamatória e reabsorção óssea periapical Haimovich et al, 2010). Para a eliminação da infecção é necessária a destruição das bactérias e seus produtos localizados não apenas na luz do canal radicular principal, mas também nas lacunas do cemento, nas crateras apicais, em todo o sistema de canais radiculares e nas áreas externas da superfície radicular (Shovelton, 1964;Leonardo, 2005;Tanomaru et al, 2008), que são áreas inacessíveis ao preparo biomecânico (Leonardo et al, 2007;Rocha et al, 2008).…”