Evaluation of chlorhexidine substantivity on human dentin: a chemical analysis.

INTRODUCTION: The aim of this study was to investigate the substantivity of chlorhexidine (CHX) solution and gel within a root canal system for 24 hours, 30 days, and 90 days. METHODS: Forty-five extracted human anterior teeth were used for this study. The samples were divided into 3 groups according to the chemical auxiliary substance used to perform the root canal preparation: group 1, 2% liquid CHX; group 2, 2% gel CHX; and group 3, distilled water (the control group). The working length was determined by inserting a #10 K-file into the canal up to the moment its tip was seen in the apex foramen and then withdrawing it 1 mm. The roots were prepared up to the instrument #45. Longitudinal grooves were carved on the free surfaces of the roots, providing 2 halves of each root and resulting in 30 samples per group. Each group was randomly divided into 3 subgroups (n = 10), and substantivity was evaluated after 24 hours, 30 days, and 90 days of incubation. The amount of CHX (in micrometers) was measured through reverse-phase high-performance liquid chromatography. Statistical analysis was performed by analysis of variance and the Tukey test for post hoc comparisons (α = 0.05). RESULTS: The control group showed no substantivity. Significant amounts of CHX solution and gel remained retained in dentin substrates independent of the time of incubation (P < .05). CHX solution showed a higher substantivity than CHX gel, with the exception of groups incubated for 90 days. The decreasing amounts of retained CHX inside the canal were for 24 hours >30 days >90 days for CHX solution and 24 hours >30 days ≥ 90 days for CHX gel. CONCLUSIONS: The results of this study indicate that CHX solution and gel are retained in root canal dentin for up to 90 days.

Effect of root-canal sealer on the bond strength of fiberglass post to root dentin.

OBJECTIVE: To evaluate the effects of different root-canal sealers on the bond strength of a fiberglass post cemented with self-adhesive resin cements. MATERIAL AND METHODS: Forty extracted maxillary single-rooted canines were prepared with the crown-down technique and randomly divided into four groups according to the tested sealer: Group 1: control group, gutta-percha cone only (no sealer); Group 2: EndoREZ; Group 3: Sealapex; Group 4: Endofill. The roots were obturated with the gutta-percha cone using the cold lateral compaction technique. Fiberglass posts were cemented into the prepared post spaces with the self-adhesive cement RelyX Unicem. Bonded specimens were sectioned into 1-mm thick slabs and a push-out test was performed in a universal machine. RESULTS: Data were subjected to ANOVA and Tukey tests (α = 0.05). No significant difference was detected between Groups 1-3 (P > 0.05). Group 4 showed a lower bond strength than the other sealers (P < 0.05). CONCLUSIONS: Endofill negatively interfered with the bond to root dentine; however, EndoRez and Sealapex did not affect the bond strength of the fiberglass post cemented with self-adhesive resin cements.

Análise da concentração e método de armazenagem das soluções de hipoclorito de sódio em consultórios odontológicos

Objetivo: avaliar a concentração e o método de armazenagem da solução de hipoclorito de sódio em consultórios odontológicos na cidade de Santa Cruz do Sul/RS.Métodos: foram coletadas 50 amostras da solução, onde,por meio da titulometria, foi analisada a concentração de cloro ativo. Além da coleta, foi realizado um questionário com o intuito de verificar o tipo de embalagem e da tampa em que se encontrava a solução de hipoclorito de sódio,bem como o local de armazenamento. Resultados:a análise dos resultados demonstrou que, das 50 amostras avaliadas, 38 tinham a concentração abaixo da indicada,3 apresentavam teor de cloro ativo acima do informado pelo profissional e apenas 9 tinham a concentração indicada.Quanto à embalagem em que as soluções de hipoclorito eram armazenadas, das 50 amostras coletadas,40 eram armazenadas em embalagens de plástico leitoso,6 em plástico âmbar, 3 em plástico transparente e 1 em vidro. Quanto ao tipo de tampa, 46 das soluções coletadas foram encontradas armazenadas em embalagens com tampa de rosca, e apenas 4 em embalagens com tampa de pressão. Além disso, das 50 soluções coletadas,43 eram armazenadas em armários, 6 em ambientes refrigerado se 1 foi encontrada em cima do balcão ao lado de uma estufa. Conclusão: a maioria das soluções de hipoclorito de sódio coletadas e analisadas apresentou uma porcentagem de cloro ativo inferior ao informado pelo profissional, eram armazenadas em embalagens de plástico leitoso com tampa de rosca, e mantidas à temperatura ambiente em armários

Avaliação da resistência à compressão de duas resinas compostas em diferentes espessuras submetidas a diferentes tempos e complementação de polimerização / Compressive strength evaluation of two composite resins in different thickness tested with different light-cure times and heat treatment

O objetivo deste trabalho foi analisar a resistência a compressão das resinas compostas P60 e 2250 (3M IESPE) em diferentes espessuras: 1, 2 e 4mm; submetidas a diferentes tempos defotopolimerização. Foram confeccionados 180 espécimes, subdivididos nos seguintes grupos: Aespessuras de 1. 2 e 4mm, para cada resina (n=10), com tempo de polimerização de 20s; B - espessuras de 1, 2 e 4 mm, para cada resina (n=10), com tempo de poliinerização de 40s; C -espessuras de 1, 2 e 4mm para cada resina (n=lO), com tempo de polimerizaçâo de 20s mais complementação de polimerizaçâo em fomo de microondas durante 5 min, potência 950W. As resinas foram inseridas em uma matriz metálica (3mm de diâmetro. altura variando 1, 2 e 4mm), sendo que a fotopolimerização ocorreu no lado superior do espécime. Os espécimes foram levados amáquina deensaio universal v a a t 500, com força de compressão axial na velocidade de 1 rnmlmin.Os resultados foram analisados pelos testes estatísticos NOVA e Tukey (P<0,05), que demonstrou que a resina PGO apresentou maior resistência a compressão na espessura de 1 mm em relação a 2mm, para 20 segundos de fotopolimerizaçào. Aresina 2250 apresentou maior resistência coinpressiva na espessura de I mm em relação a 2mm e4mm para 20 segundos de fotopolimerização, e em relaçiioa 4mm para40 segundos de fotopolimerizaçâo. Acomplementação de polimeri7ação nâo modificouo desempenho das resinas P60 e 2250, as quais apresentaram um comportamento semelhante emrelação a resistência compressiva e condizente com espessuras de 1 min.

The aim of this study was to evaluate P60 and 2250 (3MIESPE) compressive strength in different thickness: 1,2 and 4mm; light cured in different ways. It was made 180 specimensdivided in to 3 groups: A- 1,2 and 4 mm thickness for each resin (n=lO) lightcured by 20s; B - 1.2 and 4mm thickness for each resin (n=10) ligthcured by 40s; C - 1.2 and 4 mm thickness for each resin (n=10) lightcured by 20s plus a microwave oven by 5 minutes, at 950W power.Those resins were put inside a cylindrical inetal matrix (3mm diameter x 1, 2 or 4 mm high); lightcuring tip was applied in a top side of the specimens. The specimens were tested in auniversal testing machine (Versat 500), with axial coinpressive direction, with Imm/min speed. The results were analysed by ANOVA, with 5% significance level, that showed statistically significance difference among those groups (P<0,05). Then, it was used Tukey's test, that showed higher compressive strenght for P60 in 1 mm thickness, in relation to 2mm, using 20s lightcuring for 2250 resin, high compressive strength was found for Imm thickness in relation to 2mm and 4mm for 20s lightcuring and 4mm thickness for 40s Iightcuring. The microwave oven use, as well as, 40s lightcuring did not turn P60 and 2250 better, in relation to compressivestrenght, evaluated in same thickness. P60 and 2250 composite resins did not show statiscally significant difference between them.

Comparative in vivo analysis of the sealing ability of three endodontic sealers in dog teeth after post-space preparation.

This study compared the sealing ability of RoekoSeal, AH Plus and EndoRez in dog premolars after post-space preparation and exposure to the oral environment. Seventy-four root canals were cleaned, shaped and filled with gutta-percha and one of the sealers. Post spaces were prepared with about 4-mm root canal filling remaining in the apex. Teeth were sealed for 24 h for sealer setting. Teeth were exposed to the oral environment for 45 days. The dogs were killed and root canals were soaked in India ink and sealed for 96 h. The teeth were cleared, and leakage was measured under stereoscopy. The Kruskal-Wallis test was used for analysis. A significant difference was found between EndoRez and RoekoSeal groups (P < 0.05). EndoRez had lower leakage values than RoekoSeal after 45-day exposure to the oral environment. No statistic difference was found in the comparison of AH Plus with the other sealers under study.

Microbial leakage and apical inflammatory response in dog's teeth after root canal filling with different sealers, post space preparation and exposure to the oral environment

Coronal leakage is an important factor affecting the outcome of endodontic therapy. This study evaluated the microbial leakage (ML) and the apical inflammatory response (AIR) in dog's teeth after root canal filling with three endodontic sealers, post preparation and exposure to the oral environment, testing the hypothesis that there is a positive correlation between these two histological parameters (ML and AIR). Sixty-four root canals of 8 mongrel dogs were cleaned, shaped and randomly distributed into groups according to the sealer to be used: Sealer 26 (n=18); AH Plus (n=18); RoekoSeal (n=19); no sealer - control group (n=9). Root canals were filled by the lateral condensation technique. Post space preparation left 4 mm of filling material in the apical root third, and specimens were exposed to the oral environment for 90 days. The dogs were killed and jaw blocks were histologically processed using Brown & Brenn and HE staining techniques. ML and AIR were scored from 1 to 4. Results were analyzed statistically using ANOVA, Duncan's post-hoc test and Spearman's correlation. ML and AIR score means were: Sealer 26 - 2.44±0.98 and 2.50±0.70; AH Plus - 2.50±0.78 and 2.22±0.54; RoekoSeal - 1.84±0.95 and 2.63±0.83; Control - 2.56±1.23 and 3.11±0.60. Statistically significant differences in AIR scores were found between the AH Plus and control groups (p<0.05). Although RoekoSeal had the lowest ML means, and AH Plus, the lowest AIR means after 90-day exposure to the oral environment, no statistically significant differences were found between the three sealers under study, and no correlation was found between ML and AIR.

Avaliação, in vitro, da atividade antimicrobiana de três cimentos endodônticos / In vitro analysis of antimicrobial activity of theree endodontic sealers

O presente estudo teve como objetivo avaliar, in vitro, a atividade antimicrobiana dos cimentos endodônticos AH Plus (A), Endofill (E) e Sealer 26 (S), imediatamente após a manipulação, em contatos com culturas isoladas de E. faecalis (EF), P. aeruginosa (PA), S. aureus (SA) e C. albicans (CA). Para tanto, foram confeccionados 9 corpos de prova de cada um dos materiais a partir de discos de papel filtro com 5 mm de diâmetro. Oito destes, 2 para cada microrganismo, foram colocados sobre placas de Petri, contendo meio de cultura Brain Hart Infusion-Agar (BHI-A) inoculado. O último foi colocado sobre uma placa com meio de cultura estéril (controle de esterilidade). Uma placa com BHI-A não inoculado serviu de controle negativo. As placas foram levadas a estufa bacteriológica e 48 horas após realizou-se a medida dos halos de inibição de crescimento microbiano com auxilio de paquímetro digital. Para o grupo do A, E e S, respectivamente, a média dos halos, em milímetros, foi de: 0,70, 3,13 e 1,79 para EF; 1,08, 3,40 e 3,01 para PA; 0,72, 3,16 e 4,03 para SA; 1,32, 2,59 e 1,40 para CA. O controle negativo e o controle de esterilidade dos materiais evidenciaram ausência de crescimento microbiano. Conclui-se que todos os cimentos testados apresentaram atividade antimicrobiana em contato com as culturas estudadas, sendo que para EF, PA e CA a ordem crescente do diâmetro do halo de inibição foi: A, S e E. Para SA a ordem crescente foi: A, E e S.

Estudo da padronização de cones de guta-percha de três marcas comerciais / Study on the standardization of gutta-percha cones provided by three different manufacturers

Objetivos: Avaliar o diâmetro da ponta de cones de guta-percha principais, de 1ª e 2ª séries, das marcas Tanari, Endopoints e Dentsply-Maillefer. Método: O diâmetro do milímetro final da extremidade menos calibrosa de 360 cones (10 de cada número em cada marca comercial) foi mensurado com auxílio de um paquímetro digital. Cada um dos cones foi mensurado três vezes, sendo calculada a média aritmética para a obtenção do diâmetro final. A comparação entre o diâmetro dos cones com o diâmetro ideal, de acordo com a especificação da American National Standards Institute/American Dental Association (ANSI/ADA) n. 78, foi realizada pelo teste t-student. Para comparar os cones de um mesmo calibre de diferentes marcas comerciais utilizou-se a análise de variância e o teste de comparações múltiplas de Tukey. O nível de significância adotado foi de 5%. Resultados: A análise estatística mostrou que apenas os cones de número 15 não diferiram entre as marcas estudadas. O diâmetro da ponta dos cones de guta-percha números 35 e 55, da Tanari, 15, 45 e 70, da Endopoits, e 20, 25, 30, 35, 40, 45, 50, 55, 60, 70, 80, da Dentsply-Maillefer, apresentou diferenças estatisticamente significativas (p≤0,05) quando comparado ao valor estabelecido pela especificação da ANSI/ADA n. 78. Conclusão: Os cones de guta-percha números 35 e 55 da Tanari, números 15, 45 e 70 da Endopoints e todos, com exceção dos de número 15, da Dentsply-Maillefer, não estão de acordo com a especificação da ANSI/ADA n. 78.

Microbial leakage and apical inflammatory response in dog's teeth after root canal filling with different sealers, post space preparation and exposure to the oral environment.

Coronal leakage is an important factor affecting the outcome of endodontic therapy. This study evaluated the microbial leakage (ML) and the apical inflammatory response (AIR) in dog's teeth after root canal filling with three endodontic sealers, post preparation and exposure to the oral environment, testing the hypothesis that there is a positive correlation between these two histological parameters (ML and AIR). Sixty-four root canals of 8 mongrel dogs were cleaned, shaped and randomly distributed into groups according to the sealer to be used: Sealer 26 (n=18); AH Plus (n=18); RoekoSeal (n=19); no sealer - control group (n=9). Root canals were filled by the lateral condensation technique. Post space preparation left 4 mm of filling material in the apical root third, and specimens were exposed to the oral environment for 90 days. The dogs were killed and jaw blocks were histologically processed using Brown & Brenn and HE staining techniques. ML and AIR were scored from 1 to 4. Results were analyzed statistically using ANOVA, Duncan's post-hoc test and Spearman's correlation. ML and AIR score means were: Sealer 26 - 2.44+/-0.98 and 2.50+/-0.70; AH Plus - 2.50+/-0.78 and 2.22+/-0.54; RoekoSeal - 1.84+/-0.95 and 2.63+/-0.83; Control - 2.56+/-1.23 and 3.11+/-0.60. Statistically significant differences in AIR scores were found between the AH Plus and control groups (p<0.05). Although RoekoSeal had the lowest ML means, and AH Plus, the lowest AIR means after 90-day exposure to the oral environment, no statistically significant differences were found between the three sealers under study, and no correlation was found between ML and AIR.