Quantitative radiographic evaluation of periapical bone resorption in dog's teeth contaminated with bacterial endotoxin (LPS) associated or not with calcium hydroxide

The aim of this study was to quantify radiographically the periapical bone resorption in dogs' teeth contaminated with bacterial endotoxin (LPS), associated or not with calcium hydroxide. After pulp tissue removal, 60 premolars were randomly assigned to 4 groups and were either filled with LPS (group 1), filled with LPS plus calcium hydroxide (group 2) or filled with saline (group 3) for a period of 30 days. In group 4, periapical lesion formation was induced with no canal treatment. Standardized radiographs were taken at the beginning of the treatment and after 30 days and the Image J Program was used for measurement of periapical lesion size. Periapical lesions were observed in groups 1 (average of 8.44 mm2) and 4 (average of 3.02 mm2). The lamina dura was intact and there were no areas of periapical bone resorption in groups 2 and 3. It may be concluded that calcium hydroxide was effective in inactivating LPS, as demonstrated by the absence of apical periodontitis in the roots that were filled with bacterial endotoxin plus calcium hydroxide.

O objetivo deste estudo foi quantificar radiograficamente a reabsorção óssea periapical em dentes de cães contaminados com endotoxina bacteriana (LPS), associadas ou não ao hidróxido de cálcio. Sessenta pré-molares foram divididos em 4 grupos e preenchidos com LPS (grupo 1), LPS e hidróxido de cálcio (grupo 2), solução salina (grupo 3), ou lesões periapicais foram induzidas sem tratamento (grupo 4), por um período de 30 dias e o Programa Image J foi empregado para mensuração das lesões, em mm2. Radiografias foram realizadas no início do tratamento e após 30 dias. Lesões periapicais foram observadas no grupo 1 (média de 8,44 mm2) e 4 (média de 3,02 mm2). A lâmina dura estava intacta e não foram observadas áreas de reabsorção óssea periapical nos grupos 2 e 3. Concluindo, a avaliação radiográfica quantitativa do efeito do LPS associado ao hidróxido de cálcio demonstrou que quando juntos a endotoxina bacteriana é inativada, uma vez que não foram observadas lesões periapicais nas raízes deste grupo experimental.