Influence of different volumes of EDTA for final rinse on smear layer removal

Objective. The aim of this study was to analyze the influence of different volumes of 17% EDTA for final rinse on smear layer removal on the different areas of the root canal. Study design. Forty single-rooted teeth were instrumented using rotary instruments. The teeth were divided into 3 test groups according to the EDTA volume for final rinse (5 mL, 10 mL, 15 mL) and 1 control group (10 mL of 1% sodium hypochlorite). The roots were axially split into halves, and the smear layer removal from the canals was determined under scanning electron microscope. The data were analyzed using Kruskal Wallis and Dunn tests. Results. The 3 experimental groups showed no statistical difference (P > .05); however, when the test groups were compared to the control group statistically significant differences were found (P < .01). The root canal wall surfaces of teeth in the control group showed the presence of heavy smear layer through the entire length of the root canals. The other groups showed mainly smear layer-free surfaces or a small amount of debris. When coronal, middle and apical thirds were compared, there was no statistically significant difference (P > .05). Conclusions. Based on the results, it appears that a final rinse with 5 mL of EDTA per canal provides good smear layer removal, with root canal walls free of debris and mostly open dentinal tubules in all areas. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106:e40-e43

Spectrophotometric and visual analysis of internal dental bleaching utilizing laser and heat as catalyzing sources

This experiment aimed at evaluating, in vitro, the chromatic alteration of dental crowns submitted to internal bleaching. Color alterations were evaluated by means of spectrophotometric analysis and visual observation, at the following experimental phases: initial reading (LI), after-darkening reading (LE), immediate after-bleaching reading (LC), bleaching checked after 15 days (LC15) and after 30 days (LC30). After finding the values of L* (luminosity), a* and b* (shade and saturation), which made it possible to quantify the chromatic alterations of the specimens, color differences (deltaE ) were assessed by means of the CIE Lab Program. The statistical analysis of the results did not reveal any significant difference between conventional bleaching and bleaching activated by Er:YAG laser. No statistical difference was observed between the results after 15 and 30 days, for both experimental groups.O presente experimento avaliou, in vitro, a alteração cromática das coroas dentais inicialmente, registrada a partir de uma análise espectrofotométrica e da observação visual, nos seguintes tempos experimentais: leitura inicial (LI), leitura após o escurecimento (LE) e leitura imediatamente após o clareamento (LC), leitura 15 dias após o clareamento (LC15) e leitura 30 dias após o clareamento (LC30). Depois de encontrados os valores de L* (luminosidade) a* e b* (matiz e saturação), com os quais se quantificou as alterações cromáticas dos espécimes; as diferenças de cor (deltaE) foram obtidas com auxílio do programa CIE Lab. A análise estatística dos resultados obtidos, pelo estudo espectrofotométrico, não mostrou diferença significante quando comparado o procedimento de clareamento tradicional com o ativado por laser Er:YAG. Não houve diferença estatística entre os grupos nos tempos experimentais de 15 e 30 dias

In vivo qualitative analysis of the biocompatibility of different cyanoacrylate-based adhesives

Cyanocrylates have been widely used in the medical and dental fields for several years. In Dentistry, cyanoacrylates have been used for suturing, pulp capping, as retrofilling material in endodontic surgeries, and as cervical plug for pulpless teeth bleaching. The biocompatibility of these adhesives has been the topic of many researches and subcutaneous implantation is an effective methodology for these studies. The present study evaluated the biocompatibility of three different cyanoacrylate-based adhesives. Thirty-six Wistar rats were used, divided into four groups of 9 animals each: A (control) - distilled water, B - cyanoacrylate ester (Super Bonder), C - n-butyl-cyanoacrylate (Histoacryl) and D - alpha-cyanoacrylate (Three Bond). The materials were dispensed in sponges of polyvinyl chloride, the animals were incised and the sponges were inserted in the subcutaneous tissue and sutured. Each group was sub-divided according to the time of sacrifice of the animals: 7, 21 and 45 days. Subjective analysis of the histologic material showed that all groups presented some degree of irritability, but the inflammatory reaction decreased with the experimental time in all groups. Group D showed an inflammatory reaction which was closer to that of the control group and was considered to have good biocompatibility. Groups B and C were similar and presented more aggressive inflammatory reactions when compared to the control group. Based on the results, it was concluded that alpha-cyanoacrylate (Three Bond) was the most biocompatible adhesive because it caused the lowest levels of inflammation

In vitro evaluation of the antimicrobial activity of endodontic sealers Avaliação in vitro da atividade antimicrobiana de cimentos endodônticos

The purpose of this study is to evaluate the antimicrobial activity of the endodontic sealers: N-Rickert, Sealapex, AH Plus, Mineral Trioxide Aggregate (MTA) and portland cement. The Agar diffusion method was used in plates previously inoculated with the following microorganisms: C. albicans, S. aureus, E. faecalis, E. coli. The diameters of microbial inhibition zones were measured after 24 hours of incubation in kiln at 37&deg;C. According to the methodology used, it was possible to conclude that only the sealers AH Plus and N-Rickert presented antimicrobial activity against C. albicans, S. aureus, and E. coli; no antimicrobial activity in MTA, Sealapex and portland cement was observed. N-Rickert presented the largest inhibition zones varying from 8 to 18 mm, and the microorganism E. faecalis was resistant against all sealers tested.<br>O objetivo deste estudo é avaliar a capacidade antimicrobiana dos cimentos obturadores de canal: N-Rickert, Sealapex, AH Plus e também do Agregado Trióxido Mineral (MTA) e Cimento de Portland. O método utilizado foi a difusão em Ágar, em placas previamente inoculadas com os seguintes microorganismos: C. albicans, S. aureus, E. faecalis, E. coli. A leitura do diâmetro do halo de inibição do crescimento microbiano foi realizada, após 24 horas de incubação, em estufa a 37&deg;C. De acordo com a metodologia empregada, foi possível concluir que: somente os cimentos obturadores AH Plus e N-Rickert apresentaram atividade antimicrobiana contra C. albicans, S. aureus e E. coli; não foi observada atividade antimicrobiana no cimento de Portland, MTA e Sealapex. O cimento N-Rickert apresentou halos de inibição maiores variando de 8 a 18 mm. O microorganismo E. faecalis foi resistente contra todos os cimentos testados