Comparative study of the sealing ability of a polydimethylsiloxane-based root canal sealer

O objetivo deste estudo foi comparar a capacidade de selamento de três cimentos endodônticos, RSA (cimento à base de silicone), Endion (cimento à base de ionômero de vidro) e Topseal (cimento à base de resina epóxica), com e sem remoção de smear layer. Noventa dentes humanos extraídos foram selecionados e distribuídos em 6 grupos (n=15), de acordo com os seguintes protocolos: em 3 grupos, a smear layer foi mantida e os canais radiculares foram obturados com cones de guta-percha e com os cimentos RSA, Endion e Topseal, respectivamente. Nos outros 3 grupos, a smear layer foi removida e os canais radiculares foram obturados da mesma forma. A microinfiltração foi avaliada aos 7 dias, 1 mês e 2 meses, utilizando o sistema de transporte de fluído. Os resultados foram expressos em µL/24 h. Os dados foram analisados estatisticamente por meio dos testes não-paramétricos de Kruskall-Wallis e Mann-Whitney. Os resultados demonstraram que o grupo obturado com Topseal sem smear layer apresentou infiltração significativamente menor (p<0.05) que o grupo obturado com cimento RSA sem smear layer, em todos os períodos avaliados. Não houve diferença estatisticamente significante (p>0.05) entre os outros grupos, nos intervalos de avaliação estabelecidos. Os achados deste estudo demonstraram que o cimento à base de silicone (RSA) não apresentou melhor capacidade de selamento que os outros cimentos, na presença ou ausência de smear layer. Dentre os cimentos endodônticos avaliados, o Topseal apresentou os menores valores de microinfiltração.

Comparative study of the sealing ability of a polydimethylsiloxane-based root canal sealer.

The purpose of this study was to compare the sealing ability of three root canal sealers, RSA (polydimethylsiloxane sealer), Endion (glass-ionomer sealer) and Topseal (epoxy resin sealer), with and without smear layer removal. Ninety extracted human teeth were selected and assigned to 6 groups (n=15), according to the following protocols: in 3 groups, the smear layer was left intact and the root canals were obturated with gutta-percha points and RSA, Endion and Topseal, respectively; in the other 3 groups, the smear layer was removed and the root canals were obturated in the same way as described above. Microleakage was measured at 7 days, 1 month and 2 months, using the fluid transport model. The results were expressed in microL/24 h. Data were analyzed statistically by Kruskall-Wallis and Mann-Whitney non-parametric tests. The results showed that the Topseal group without smear layer leaked significantly less (p<0.05) than the RSA group without smear layer, at all experimental periods. No statistically significant differences (p>0.05) were found among the other groups, at the established evaluation intervals. The findings of this study showed that the polydimethylsiloxane sealer (RSA) did not yield better sealing ability than the other sealers, either in the presence or in the absence of smear layer. Topseal had the least microleakage from the root canal sealers evaluated.

Comparative study of apical sealing ability of a new resin-based root canal sealer.

The purpose of this study was to compare the microleakage of two root canal sealers, Fibrefill (resin-based sealer) and calciobiotic root canal sealer (CRCS; calcium hydroxide-based sealer), with and without the presence of smear layer. The model used for the measurement of microleakage was a fluid transport model. Sixty human extracted teeth were used in this study. The teeth were divided into four groups and treated as follows. In group A, the smear layer was left intact, and canals were obturated with gutta-percha and Fibrefill. In group B, the smear layer was removed, and canals were obturated with gutta-percha and Fibrefill. In group C, the smear layer was left intact, and the canals were obturated with gutta-percha and CRCS. In group D, the smear layer was removed, and canals were obturated with gutta-percha and CRCS. Microleakage was measured at 7 days, 1 month, and 2 months. The results showed that the Fibrefill groups with and without smear layer leaked significantly less than the CRCS groups at all experimental times. No significant difference was found between the groups of same materials, but the microleakage values were less when the smear layer was removed.

Adhesion of a new methacrylate resin-based sealer to human dentin.

The purpose of this study was to compare the shear bond strength of four root canal sealers: Fibrefill (a methacrylate resin sealer), Endion (a glass ionomer sealer), Topseal (an epoxy resin sealer), and CRCS (a calcium hydroxide sealer) to human root canal dentin. The dentin specimens were divided into four groups of 12 specimens each and etched with 3 ml of EDTA 17% before rinsing with NaOCl 2.5% and distilled water. Bond strength was tested using a test machine by subjecting samples to a shear load at a cross-head speed of 0.5 mm/min. The best results were observed in the Fibrefill group, in which the mean shear bond strength was 7.993 +/- 2.365 MPa. The values in the Endion (1.816 +/- 0.614 MPa) and CRCS (2.224 +/- 0.509 MPa) groups were significantly lower than in the Fibrefill and Topseal (6.235 +/- 1.428 MPa) groups. Inspection of the fractured surfaces revealed the bond failure to be mainly adhesive to dentin for Fibrefill and cohesive for Endion sealer. CRCS and Topseal sealers showed both adhesive and cohesive failures.

Comparative study of sealing ability of two root-end-filling materials with and without the use of dentin-bonding agents.

The purpose of this study was to examine microleakage of two root-end-filling materials with and without the use of bonding agents. For microleakage measurement a fluid transport model was used. Sixty single-rooted teeth were used in this study. They were prepared with step-back technique and then an apicoectomy was performed. Then the teeth were divided into four groups. Group A were filled with Fuji II LC glass-ionomer cement, group B were filled with Fuji II LC and a new bonding agent, Fuji Bond, group C were filled with Admira composite resin, and group D were filled with Admira and Admira Bond, a new bonding agent. At 24 h, 1 month, and 2 months after filling the leakage along these filling materials was determined under a low pressure of 0.1 atm. At all experimental times, glass-ionomer groups showed significantly less microleakage than resins groups. Between Admira and Admira Bond groups, significantly less leakage was observed in the root sections with Admira Bond at 24 h.