Influence of Apical Preparation Size and Working Length on Debris Extrusion

Abstract The aim of this study was to quantitatively evaluate the amount of apically extruded debris by single-file reciprocating instruments with different working lengths and apical preparation sizes. Eighty human single-rooted mandibular incisors were used and conventional access cavities were prepared. Then, the specimens were divided into four groups (n=20), according to root canal instrumentation: Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used at the foramen; Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used 1 mm short of the foramen. Distilled water was used as an irrigant and the apically extruded debris were collected in pre-weighted glass vials and dried afterwards. The mean weight of debris was weighed with a microbalance and statistically analyzed using one-way analysis of variance and the post hoc Tukey multiple comparison test (p<0.05). The results showed that all experimental groups were associated with debris extrusion. No significant difference was found in the amount of apically extruded debris among all experimental groups (p>0.05). The present study demonstrated that the working length and the apical preparation size did not have a significant effect on debris extrusion when performing single-file reciprocating instrumentation.

Resumo Este estudo avaliou quantitativamente a quantidade de material extruído apicalmente pela instrumentação com lima única reciprocante, aplicando diferentes comprimentos de trabalho e tamanhos de preparo apical. Para a análise de extrusão foram utilizados oitenta incisivos inferiores unirradiculares humanos. Cavidades de acesso convencionais foram preparadas e os espécimes foram divididos em quatro grupos (n=20), de acordo com o tipo de instrumentação do canal: Reciproc 25, 0.08 e Reciproc 40, 0.06 foram utilizadas na instrumentação até o forame; Reciproc tamanho 25, 0.08 e Reciproc 40, 0,06 foram utilizadas na instrumentação até 1 mm aquém do forame. Água destilada foi empregada como irrigante e o material extruído apicalmente foi coletado em frascos de vidro já pesados e posteriormente submetidos a secagem. O peso médio de detritos foi avaliado com uma microbalança de precisão e os dados submetidos a ANOVA e teste Tukey (p<0,05). Todos os grupos experimentais foram associados à extrusão de debris. Nenhuma diferença significativa foi encontrada na quantidade de material extruído apicalmente entre os grupos (p>0,05). Este estudo demonstrou que o comprimento de trabalho e o tamanho do preparo apical não geraram efeito significativo sobre a extrusão de debris durante a instrumentação reciprocante.

Infuence of irrigation and obturation techniques on artificial lateral root canal filling capacity

The aim of this study was to evaluate the influence of two dif-ferent irrigation protocols on artificial lateral root canalfilling capacity using different obturation techniques. Sixtysingle-root human teeth were used. Two artificial lateralcanals were created in the apical third. Root canals wereinstrumented up to a 45 K-file to the working length. Beforeeach file, root canals were irrigated either with 2 mL of 2.5%NaOCl or 2% chlorhexidine gel with further irrigation withsaline solution and 3 mL of 17% EDTA. Specimens were ran-domly divided into three groups according to the obturationtechnique: (1) lateral compaction technique; (2) Taggerhybrid technique; and (3) thermoplasticized technique usingBeeFill 2 in 1. All groups used AH Plus as the root canal seal-er. The specimens were decalcified and cleared in methylsalicylate. The total length of lateral canals was observedunder X30 magnification with a stereomicroscope and meas-ured on the buccal and lingual root surfaces using Leica IM50software. The data were submitted to ANOVA and Tukey test(p<0.05). Among the obturation techniques, BeeFill 2 in 1showed deeper penetration into all lateral canals than the lat-eral compaction or Tagger hybrid techniques (p<0.05). Thelateral compaction group showed the worst results (p<0.05).Irrigants did not affect the outcome; there was no differencebetween NaOCl and chlorhexidine when the same obturationtechnique was used (p>0.05). Regardless of the irrigant usedduring endodontic procedures, the thermoplasticized tech-niques showed higher penetration behavior for filling artificiallateral canals than the lateral compaction technique.

O objetivo do presente estudo foi avaliar a influência de doisdiferentes protocolos de irrigação na capacidade de penetraçãode canais artificiais, utilizando diferente técnicas de obturação.Sessenta dentes humanos unirradiculares foram utilizados. Doiscanais laterais artificiais foram confeccionados no terço apicaldo dente. Os canais foram instrumentados até uma lima K 45 nocomprimento de trabalho. Antes do uso de cada lima, os canaisradiculares foram irrigados com 2 mL de NaOCl 2.5% ou comClorexidina gel 2% seguido de solução salina. Ambos os gruposreceberam no final da instrumentação 3 mL de EDTA 17%. Osespecimes foram randomicamente separados em 3 subgrupos deacordo com a técnica de obturação utilizada: (1) técnica de com-pactação lateral; (2) técnica híbrida de Tagger; e (3) técnicatermoplástica utilizando o BeeFill 2 em 1. Em todos os grupos ocimento utilizado foi o AH Plus. Depois, os elementos foramdiafanizados utilizando metil salicilato. As extensões de pe -netração dos cimentos nos canais laterais foram realizadas uti-lizando estereomicroscópio (X30). Os dados de cada grupoforam analizados utilizando ANOVA e o teste de Tukey (p<0.05).Dentre as técnicas de obturação, a técnica termoplástica uti-lizando o BeeFill 2 em 1 mostrou a maior penetração em canaislaterais (p<0.05). A técnica de compactação lateral apresentouos piores resultados dentes os grupos testados (p<0.05). Os irri-gantes não afetaram a penetração dos canais laterais; não foramobservados diferenças entre NaOCl e clorexidina, quando amesma técnica de obturação foi utilizada (p>0.05). Pode-se con-cluir que independente da substância química auxiliar utilizada,as técnicas termoplásticas de obturação demonstraram maiorpenetração de canais laterais do que a técnica de compactação lateral.

Avulsion of permanent teeth with open apex: a systematic review of the literature

Introduction: Considered the most serious of dental injuries, avulsion is known as the total displacement of tooth out of its socket. Treatment includes immediate replantation and its success is directly related to several factors. Objective: This paper aimed to review the literature in a systematic way on dental avulsion of permanent teeth with open apex, covering various topics such as: reason for avulsion; storage media; time out of the socket; use of antibiotics; splinting time; tooth vitality; presence of resorption and/or obliteration of pulp canal; and following-up time. Material and methods: PubMed/MedLine database and Dental Traumatology journal were searched, from May to June of 2011, and several studies comprising the current and classic literature were listed using the following terms: tooth avulsion, open apex, permanent and case report. Results and conclusion: Twelve cases reports were selected. Cases of dental trauma in open apex teeth may have a good prognosis if the following steps are taken: the hydration of the tooth and immediately replantation. It is important to search dental care, even if everything seems solved, and the tooth following-up should be performed periodically as informed by the dentist.