RESUMEN
AIM: To assess the penetration of sodium hypochlorite (NaOCl) gel or NaOCl solutions with surfactants, and the effect of passive ultrasonic irrigation (PUI) on penetration into dentinal tubules. METHODOLOGY: Bovine incisor root canals were instrumented, the roots sectioned and the dentine blocks obtained were stained with crystal violet. Dentine blocks (n = 10 per group) were exposed to 3% NaOCl gel or 3% NaOCl solution for 10 and 20 min. Other dentine blocks (n = 10 per group) were exposed to Chlor-Extra (6% NaOCl + surfactant), 6% NaOCl, 2.5% NaOCl with 0.2% cetrimide and 2.5% NaOCl for 10 and 20 min. The penetration depth of irrigants into dentinal tubules was measured in micrometres by viewing the bleached crystal violet under a stereomicroscope. Additionally, bovine incisor root canals, instrumented and stained with crystal violet, were distributed into two groups (n = 10) and irrigated with 2.5% NaOCl with PUI or conventional syringe irrigation (CSI). The penetration depth of irrigants into dentinal tubules was assessed 3 and 7 mm from the apex. Statistical analysis was performed by ANOVA and Tukey tests (α = 0.05). RESULTS: There was significantly greater penetration of 3% NaOCl solution into dentinal tubules compared with the gel form (P < 0.05). There was no difference (P > 0.05) between 6% NaOCl and Chlor-Extra, and between 2.5% NaOCl and 2.5% NaOCl + cetrimide. PUI significantly increased the penetration depth of NaOCl into dentinal tubules when compared with CSI (P < 0.05). CONCLUSIONS: In extracted bovine incisors, NaOCl gel penetrated less into dentinal tubules than NaOCl solution. The addition of surfactants did not increase the penetration depth. The use of PUI significantly increased NaOCl penetration into dentinal tubules.
Asunto(s)
Dentina/efectos de los fármacos , Irrigantes del Conducto Radicular/farmacocinética , Hipoclorito de Sodio/farmacocinética , Raíz del Diente/efectos de los fármacos , Animales , Bovinos , Geles , Técnicas In Vitro , Soluciones , Tensoactivos/farmacología , Irrigación Terapéutica/métodos , Ultrasonido/métodosRESUMEN
AIM: To evaluate the influence of powder-to-gel ratio (0.19 g powder to 50 µL of gel, thick MTA Flow, and 0.06 g powder to 50 µL of gel, fluid MTA Flow) on biocompatibility of MTA Flow (Ultradent Products Inc., South Jordan, UT, USA, lot: 2015122901) and compare it with Biodentine (Septodont Inc., Saint-Maur-des-Fossés, France, lot: B18542A). METHODOLOGY: The materials were manipulated and inserted into polyethylene tubes for implantation in twenty rats. After 7, 15, 30 and 60 days, the specimens were removed and embedded in paraffin. Haematoxylin and eosin sections were used to count the number of inflammatory cells (IC) and fibroblasts mm-2 (Fb). In the Masson's trichrome-stained sections, the fibrous capsule thickness was measured; picrosirius red-stained sections were used for birefringent collagen quantification. The data were submitted to two-way ANOVA and Tukey test (P ≤ 0.05). RESULTS: A significantly lower number of IC and consequently higher number of Fb were observed in the capsules adjacent to thick MTA Flow at all periods, in comparison with other materials (P ≤ 0.05). At 60 days, the quantity of birefringent collagen was significantly greater in the tissue in contact with thick MTA Flow, when compared with fluid MTA Flow and Biodentine. CONCLUSIONS: Although thick MTA Flow induced a less intense inflammatory response, all evaluated materials are biocompatible because they allowed regression of this process after 60 days.
Asunto(s)
Compuestos de Aluminio/farmacología , Materiales Biocompatibles/farmacología , Compuestos de Calcio/farmacología , Ensayo de Materiales , Óxidos/farmacología , Silicatos/farmacología , Análisis de Varianza , Animales , Colágeno , Combinación de Medicamentos , Fibroblastos/efectos de los fármacos , Fibroblastos/patología , Masculino , Modelos Animales , Materiales de Recubrimiento Pulpar y Pulpectomía/farmacología , Ratas , Materiales de Obturación del Conducto Radicular/farmacología , Factores de TiempoRESUMEN
AIM: To compare the ex vivo antibacterial effectiveness of the Endox Plus system and sodium hypochlorite (NaOCl) in combination with BioPure MTAD (Tulsa Dental, Tulsa, OK, USA) or with EDTA in Enterococcus faecalis-contaminated root canals. METHODOLOGY: After initial preparation, the root canals of 70 single-rooted human teeth were inoculated with E. faecalis (ATCC 29212) and incubated for 21 days. Specimens were divided into five groups: Endox Plus/saline; 2.5% NaOCl/MTAD; 2.5% NaOCl/EDTA; saline (positive control); negative control (root canals not prepared, nor irrigated). Samples were collected using paper points. Microbiological analysis evaluated the number of CFUs. Data were analysed by anova and Tukey tests at 0.05 significance. RESULTS: All specimens had bacterial growth after the incubation period, with similar CFU per mL counts (P > 0.05). After chemo-mechanical preparation, the number of bacteria in all groups reduced, except for the negative control. No significant differences were observed between 2.5% NaOCl/MTAD and 2.5% NaOCl/EDTA, but these groups had lower CFU counts than the other groups (P < 0.05). In the final samples, an increase in the bacterial counts was observed for Endox Plus/saline, 2.5% NaOCl/MTAD, 2.5% NaOCl/EDTA and saline (P < 0.05) with no significant differences between these groups. CONCLUSIONS: This ex vivo study revealed that the Endox Plus system was associated with a reduced antibacterial effectiveness compared with conventional irrigation using 2.5% NaOCl/MTAD and 2.5% NaOCl/EDTA. All irrigation procedures allowed recovery of bacteria 7 days after treatment, demonstrating persistence of contamination within the root canal system.
Asunto(s)
Antiinfecciosos/farmacología , Enterococcus faecalis/efectos de los fármacos , Irrigantes del Conducto Radicular/farmacología , Análisis de Varianza , Ácido Cítrico/farmacología , Recuento de Colonia Microbiana , Doxiciclina/farmacología , Ácido Edético/farmacología , Humanos , Polisorbatos/farmacología , Hipoclorito de Sodio/farmacología , Estadísticas no ParamétricasRESUMEN
AIM: To determine the influence of filling technique and root canal area on the percentage of gutta-percha (PGP) in laterally compacted root fillings. METHODOLOGY: Sixty extracted canine teeth were accessed and the root canals instrumented to the same size. They were then divided in three groups and filled with laterally compacted gutta-percha cones and AH Plus using different techniques. A variation of cold lateral compaction using a sequence of spreaders prior to accessory cone placement was compared to two commonly-used techniques. Twenty additional canines with prepared root canals were used as negative controls in which gutta-percha was introduced into the canals but no compaction applied. The roots were sectioned horizontally at 3 and 6 mm from the apex and micro-photographs taken. Using software, the area of the canals and gutta-percha at each level were measured and PGP calculated. A Multivariate analysis was used to determine the variables influencing PGP. A linear regression test was used to verify the variation in PGP explained by canal area. RESULTS: At each level the largest canal was two to three times wider than the smallest. Canal area significantly influenced the PGP at both levels (P < 0.05), however, the variation in PGP was only partially explained by canal area (r(2) = 0.154, 6 mm; r(2) = 0.119, 3 mm). The PGP at the 3 mm level was lower than at 6 mm (P = 0.003). The spreader-sequence technique achieved a higher PGP than the other two techniques (P = 0.00002). The control group had the lowest area of GP. CONCLUSIONS: Variations in root canal filling technique and canal area influenced the percentage of gutta-percha of laterally compacted root fillings. The percentage of gutta-percha was lower at the 3 mm level compared to the 6 mm level.
Asunto(s)
Cavidad Pulpar/anatomía & histología , Gutapercha/análisis , Materiales de Obturación del Conducto Radicular/análisis , Obturación del Conducto Radicular/métodos , Diente Canino , Resinas Epoxi , Humanos , Modelos Lineales , Fotografía Dental , Obturación del Conducto Radicular/instrumentaciónRESUMEN
The cytotoxicity of four calcium hydroxide-based root canal sealers (Sealapex, CRCS, Apexit, and Sealer 26) and one zinc oxide-eugenol-based sealer (Fill Canal) was evaluated microscopically for morphological changes in rat peritoneal macrophages. The least cytotoxic sealer was Fill Canal, followed in increasing order of cytotoxicity by CRCS, Sealer 26, Apexit, and Sealapex.
Asunto(s)
Macrófagos Peritoneales/efectos de los fármacos , Materiales de Obturación del Conducto Radicular/toxicidad , Animales , Bismuto/toxicidad , Hidróxido de Calcio/toxicidad , Membrana Celular/efectos de los fármacos , Nucléolo Celular/efectos de los fármacos , Núcleo Celular/efectos de los fármacos , Tamaño de la Célula/efectos de los fármacos , Células Cultivadas , Cromatina/efectos de los fármacos , Citoplasma/efectos de los fármacos , Ratas , Salicilatos/toxicidad , Estadísticas no Paramétricas , Vacuolas/efectos de los fármacos , Óxido de Zinc/toxicidad , Cemento de Óxido de Zinc-Eugenol/toxicidadRESUMEN
A study of the subcutaneous connective tissue response of 24 white rats to three different formulations of gutta-percha was undertaken. The prepared specimens were examined under the light microscope after intervals of 7, 21, 60 and 120 days. The results showed identical tissue responses after the initial period of 7 days. However, after 120 days the gutta-percha supplied with the Ultrafil system presented mature granulation tissue with neither oedema nor vascular congestion, in contrast to the responses observed with the McSpadden and Obtura formulations.