Influência da irrigação ultrassônica passiva na redução de bactérias e endotoxinas dos canais radiculares: um estudo clínico randomizado / Influence of passive ultrasonic irrigation in bacteria and endotoxins from root canals: a randomized clinical study

RESUMO

Este estudo clínico analisou os efeitos dos procedimentos endodônticos e da irrigação ultrassônica passiva (PUI) em bactérias e endotoxinas de canais radiculares. Cinquenta pacientes com dentes com periodontite apical primária foram divididos de forma randomizada em dois grupos PUI (n=25) e irrigação convencional (IC) (n=25). O preparo químico-cirúrgico (PQC) foi realizado com instrumentos reciprocantes, utilizando-se NaOCl 2,5% durante o preparo; e EDTA 17%, para remoção do magma dentinário. Os canais radiculares foram preenchidos com pasta de hidróxido de cálcio por 14 dias e obturados. Foram realizadas coletas microbiológicas dos canais antes (S1) e após o PQC (S2), após os protocolos de irrigação (S3), após a medicação intracanal (S4) e após a reinstrumentação dos canais (S5). Durante o processamento das amostras, as coletas de 5 casos foram perdidas por fatores diversos. As amostras foram analisadas por PCR quantitativo para detecção e quantificação de bactérias e pelo teste turbidimétrico de LAL para detecção e determinação do nível de endotoxinas. Bactérias e endotoxinas foram observadas em 100% das amostras iniciais coletadas. Em ambos os grupos, houve diminuição significativa na concentração de endotoxinas entre uma etapa do tratamento e a etapa posterior (p<0,05). O mesmo foi observado quanto ao número de bactérias, exceto entre a remoção da medicação intracanal e a reinstrumentação antes da obturação (S5). A análise intergrupos demonstrou que, com relação às endotoxinas, não foram observadas diferenças significativas entre os grupos (p>0,05)...

ABSTRACT

The aim of this clinical study was to compare the effects of passive ultrasonic irrigation (PUI) and intracanal medication with calcium hydroxide in bacteria and endotoxins from root canal. Fifty teeth with apical periodontitis were randomly divided into two groups according to the irrigation protocol PUI (n = 25) and conventional irrigation (CI) (n = 25). The root canal preparation of all the teeth was carried out with reciprocating files and 2.5% NaOCl during preparation; and 17% EDTA for smear layer removal. The root canals were medicated with calcium hydroxide for 14 days. Microbiological sampling were performed before (S1) and after the preparation (S2) after irrigation protocols (S3), and after intracanal medication (S4 and S5). During the processing of the samples, five cases were lost for several factors. The samples were analyzed by real time PCR, for the detection and quantification of bacteria, and the turbidimetric LAL assay, for the detection and analysis of the endotoxin levels. Bacteria and endotoxins were observed in 100% of the initial samples. In both groups, there was a significant decrease in the concentration of endotoxins between one step and the subsequent step of treatment (p < 0.05). The same was observed for the number of bacteria, with the exception of the reinstrumentation after the removal of the medication (S5). The intergroup analysis showed no significant differences between groups in endotoxin reduction ( p > 0.05 ). PUI was able to reduce the number of bacteria significantly better than CI (p < 0.05). No significant statistical difference was observed between groups regarding the occurrence of cases wielding positive results for bacteria or endotoxin. It was concluded that PUI was more effective than CI in reducing the number of bacteria but not the amount of endotoxin in the root canal. Furthermore, each step of the endodontic therapy was effective in reducing both the number of bacteria as the amount of endotoxin...