Comparative Analysis of Dentinal Erosion after Passive Ultrasonic Irrigation versus Irrigation with Reciprocating Activation: An Environmental Scanning Electron Study.

INTRODUCTION: The aim of this study was to assess ex vivo the erosive effects of passive ultrasonic irrigation versus irrigation with reciprocating activation on the dentinal surface of the root canal at 3 predetermined levels using environmental scanning electron microscopy. METHODS: Ten roots of mandibular premolars were prepared using the ProTaper Universal system (Dentsply Maillefer, Ballaigues, Switzerland). The specimens were embedded in flasks cleaved longitudinally, and indentations were made 3.0, 6.0, and 9.0 mm from the apex. The specimens in the control group (n = 10) were cleaned in an ultrasonic bath containing 2.5% sodium hypochlorite and 17% EDTA and then dried. Then, environmental scanning electron microscopic images were obtained at magnification × 800. The specimens were then reassembled in their flasks, and the NaOCl and EDTA solutions were activated according to the conditions established for the experimental groups (ie, the passive ultrasonic irrigation group [n = 5] and the EasyClean (Easy Equipamentos Odontológicos, Belo Horizonte, MG, Brazil) group, irrigation with reciprocating activation with the EasyClean instrument [n = 5]). The specimens of both experimental groups were analyzed in the same manner as in the control group. Analysis of the dentinal surface topography was conducted using the 3D Roughness Reconstruction program (Phenom-World BV, Eindhoven, the Netherlands) as a means for assessing erosion. The data were evaluated by means of the Kruskal-Wallis, Student-Newman-Keuls, and Mann-Whitney tests. RESULTS: In the EasyClean group, the degree of dentinal erosion at 3.0 mm was significantly higher than at 9.0 mm. In the other comparisons, there was no statistically significant difference (P < .05). CONCLUSIONS: The final irrigation techniques tested were equivalent in relation to the degree of erosion caused to the dentinal surface.

Avaliação clínica da neutralização do conteúdo séptico/necrótico do canal radicular: técnica imediata X técnica mediata / Clinical evaluation of septic / necrotic cotent neutralization from root canal: immediate technique X mediate technique

Este trabalho avaliou a eficácia clínica de duas técnicas de neutralização do conteúdo séptico/beurótico do canal radicular. Foram utilizados quarenta dentes indicados para tratamento endodôntico, com lesao periapical visível radiograficamente, cavidade fechada e resposta negativa aos testes de sensibilidade pulpar. Os dentes foram divididos em dois grupos: Grupo 1 - neutralizaçao pela técnica imediata, crow-down com NaOCI 2,5 porcento, grupo 2 - neutralizaçao pela técnica mediata com tricresol formalina (TF) na câmara pulpar. Os dentes foram selados e após sete dias fora avaliados os sinais e sintomas clínicos, clasificando a dor pós-operatória em ausente,leve, moderada e intensa. Ao sinal do tratamento, os dentes foram obturados com guta-percha e cimento à base de hidróxido de cálcio. Os dados obtidos foram submetidos ao teste exato de Fischer com nível de significância de 5 porcento. Houve ausência de dor na maioria dos casos após as duas técnicas de neutralização avaliadas (65 porcento no grupo 1 e 75 porcento no grupo 2); quando presente, verificou-se maior número de casos de dor leve na tácnica imediata com NaOCI 2,5 porcento (25 porcento), e maior número de casos de dor intensa na técnica mediata com TF (15 porcento); três casos tratdos com TF presentaram edema pós-operatório. Concluiu-se que a neutralização do conteúdo séptico/necrótico do canal radicular, segundo o presente estudo, pode ser realizada por ambas as tácnicas.