Análise histológica da limpeza apical de canais radiculares após instrumentaçäo / Histological analysis of the apical cleaning of the root canal system after instrumentation

A limpeza do sistema de canais radiculares assume especial relevância no sucesso do tratamento endodôntico. O objetivo deste trabalho foi avaliar histologicamente a capacidade das técnicas step-back, movimentos contínuos de rotaçäo alternada (MRA) e do sistema Quantec de promover a limpeza do terço apical de canais radiculares. Os resultados demonstraram que näo houve diferença estatisticamente significante entre as técnicas testadas, sendo que, na maioria das vezes, os canais ainda apresentavam remanescentes teciduais, mormente em áreas de variaçöes da anatomia interna

Incidence of postoperative pain after intracanal procedures based on an antimicrobial strategy.

The purpose of this prospective study was to evaluate the incidence of postoperative pain after intracanal procedures based on an antimicrobial strategy. Data were examined from 627 teeth that had necrotic pulps or required retreatment. Information was obtained for each patient treated with regard to presence of preoperative pain. Occurrence of periradicular bone destruction detected by radiographs was also recorded. The operators consisted of undergraduate students, who were in their first year of clinical training. Root canals were instrumented and then medicated with a calcium hydroxide/camphorated paramonochlorophenol paste. No systemic medication was prescribed. Approximately 1 week after the initial appointment, patients were asked about the occurrence of postoperative pain and the level of discomfort was rated as no pain, mild pain, moderate pain, or severe pain. Data were statistically analyzed using the Chi-square test. Mild pain occurred in 10% of the cases, moderate in 3.3%, and severe (flare-up) in 1.9%. Postoperative pain was significantly associated with the treatment of previously symptomatic teeth without periradicular lesions (p < 0.01). No other correlations were detected between the occurrence of postoperative discomfort and other clinical conditions. There was also no difference regarding the incidence of postoperative pain between treatment and retreatment (p > 0.01). The intracanal procedures used in this study to control root canal infections showed a small incidence of postoperative pain, particularly flare-ups, even performed by inexperienced undergraduate dental students.

Ability of three root-end filling materials to prevent bacterial leakage / Capacidade de materiais de três obturações do canal radicular para prevenir infiltração bacteriana

This study evaluated the ability of three materials-a resinous root canal sealer (Sealer 26) prepared in a thick consistence, a reinforced zinc oxide-eugenol cement (IRM), and a glass-ionomer cement (Fuji IX)-in preventing bacterial leakage. Retrofilled teeth were mounted in an apparatus and then challenged by human saliva. The number of days required for the bacteria from saliva to penetrate the rrot-end filling materials was determined. Evaluation was conducted for 60 days. Leakage was observed in all teeth of the Fuji IX group, and in 95 percent (19 of 20 specimens) of the teeth retrofilled with IRM. Sixty-five percent (13 of 20 teeth) of the teeth retrofilled with Sealer 26 showed leakage. No difference was detected between Fuji IX and IRM (p > 0.05). However Sealer 26 was significantly more effective in preventing bacterial leakage when compared with other materials tested (p < 0.05)

Extrusão apical de detritos durante instrumentação com instrumentos manuais e acionados a motor / Apically extruded debris during root canal instrumentation using hand and rotary instruments

O objetivo deste trabalho in vitro foi quantificar os detritos extruídos apicalmente após instrumentação de canais com 3 técnicas. Sessenta incisivos laterais superiores foram divididos em 4 grupos e preparados pelas seguintes técnicas: técnica dos movimentos contínuos de rotação alternada (MRA) usando limas Flex-R; MRA com limas Onyx-R; sistema Pow-R, usando limas níquel-titâneo acionadas a motor; e técnica Step-Back usando Onyx-R com movimentos de limagem. Os detritos extruídos apicalmente foram coletados em filtros de papel adaptados em dispositivos individuais. Os resultados demonstraram que todas as técnicas permitiram a extrusão de detritos via forame apical. A extrusão apical de detritos durante a instrumentação com a técnica Step-Back usando movimentos de limagem foi significamente maior quando comparada com as outras técnicas testadas(p<0,05). Não houve diferença estatisticamente significante em relação à quantidade de detritos extruídos após instrumentação com as demais técnicas

Retratamento endodôntico: avaliaçäo do limite apical de esvaziamento, na remoçäo do material obturador dos canais radiculares / Endodontic retreatment: assesment of apical limit removal, in material obturated removal of the root canals

Sessenta dentes uni-radiculares obturados com guta-percha e cimento à base de óxido de zinco eugenol, cujos limites de obturaçäo estavam situados de 1 a 3 mm aquém do ápice radiográfico foram, inicialmente, esvaziados com lima Hedstroen e solvente. A seguir foram re-instrumentados pela técnica manual convencional e ultra-sônica a 1 mm aquém do forame apical. Metade das amostras, durante a instrumentaçäo foi esvaziada além do forame apical. Os resultados mostraram que o esvaziamento de todo o segmento apical favoreceu a remoçäo de material obturador dos canais radiculares