Influence of Hero Apical instruments on cleaning ovoid-shaped root canals

The cleaning capacity of Hero 642 nickel-titanium files, complemented by the Hero Apical instruments in flattened roots, was determined by histological analysis, considering the area of action of the instruments on the coronal walls and the presence of remaining debris. Twenty-four single-canal, human mandibular incisors were divided into three groups and prepared as follows: GI, instrumented with Hero 642 NiTi files 30/.06, 25/.06, 20/.06, 25/.06, and 30/.06; GII, instrumented as GI followed by Hero Apical size 30/.06; GIII, instrumented as GI followed by Hero Apical sizes 30/.06 and 30/.08, then returning to 30/.06 with pendulum movements. The apical thirds were prepared for histological processing, analyzed at 40× magnification and the images were examined morphometrically. Statistical analysis showed that GIII presented the best results for removing debris (5.22 percent ± 4.13), with more contact between the instruments and the root canal walls (19.31 percent ± 0.15). This differed statistically from GI (14.04 percent ± 4.96 debris removal, with 42.96 percent ± 7.11 instrument contact) and GII (12.62 percent ± 5.76 debris removal, with 35.01 percent ± 0.15 instrument contact). Root canal preparation with Hero 642, complemented by Hero Apical instruments (30/.06 and 30/.08, then re-instrumented with Hero Apical 30/.06 using pendulum movements), was more efficient for debris removal and allowed more contact of the instruments with the root canal walls. GII presented the worst results.

Estudo comparativo in vitro da capacidade de selamento marginal apical promovido pelos cimentos Sealapex® e Endofill® / Comparative in vitro study of the marginal apical sealing capacity of Sealapex® and Endofill® Sealers

Objetivo: Avaliar in vitro o selamento apical obtido por dois cimentos: um à base de hidróxido de Cálcio, o Sealapex® (Kerr-Sybron, Orange,USA) e outro à base de óxido de zinco e eugenol, o Endofill® (Dentsply, Petrópolis, Brasil). Método: Vinte e quatro dentes unirradiculares humanos, extraídos, foram divididos em dois grupos de dez, instrumentados e obturados pela técnica da condensação lateral com guta-percha e um dos cimentos avaliados. Quatro dentes constituíram os grupos controle positivo e negativo. Após a obturação, os espécimes foram impermeabilizados, exceto no milímetro apical (com exceção do grupo controle negativo que foi totalmente impermeabilizado), imersos em tinta nanquim por 96 horas, descalcificados, desidratados e diafanizados. Resultados: A leitura da infiltração foi realizada com o auxílio de uma lupa e os dados foram analisados estatisticamente pelo teste de Tukey. Numericamente o grupo experimental do cimento Sealapex® (Kerr-Sybron, Orange, USA) exibiu menor índice de infiltração marginal que o Endofill® (Dentsply, Petrópolis, Brasil). No grupo controle negativo não houve infiltração e no positivo a infiltração foi total. Não houve diferença estatisticamente significante entre os cimentos utilizados. Conclusão: Os cimentos apresentaram capacidade de selamento apical semelhante. Nenhum cimento obturador utilizado impediu totalmentea infiltração do corante.

Objective: To evaluate the apical seal obtained with two sealers: Sealapex (Kerr-Sybron, Orange, USA) a calcium hydroxide-based sealer and Endofill (Dentsply, Petrópolis, Brazil) a zinc oxide eugenol-based sealer. Method: Twenty four extracted single-rooted human teeth were divided into two groups, with ten each, instrumented and filled by lateral condensation technique with gutta-percha and one of the sealers. Four teeth were used as positive and negative control. After filling, all specimens were coated with nail vernish except around the apical foramen (the negative control group was completely covered), and then immersed in indian ink for 96 hours, decalcified, dehydrated and diaphanized. Results: The extent of staining was examined under a stereo microscope and the data were statistically analyzed by the Tukey test. Numerically Sealapex (Kerr-Sybron, Orange, USA) experimental group had lower levels of marginal leakage than Endofill (Dentsply, Petrópolis, Brasil). The negative control exhibited no leakage and in the positive control leakage was complete. There was no statistically significant difference between the sealers. Conclusion: The sealers showed similar apical sealing ability. Neither of the sealers in this study completely prevented leakage.