Abstract: Biodentine in endodontic practice has been widely investigated, but comprehensive histological descriptions of degenerative and inflammatory responses are not covered in most of the studies that compare pulp capping materials. This study aimed to evaluate pulpal responses to mineral trioxide aggregate (MTA Angelus) and Biodentine, focusing on mineralized barrier formation and on inflammatory and degenerative events. 80 male Wistar rats were assigned to 5 groups, according to the materials used for pulp capping and coronal sealing (n=8 per group/period). The lower first molars were mechanically exposed, capped with either MTA or Biodentine, and restored with silver amalgam. In an additional test group, the teeth were capped and sealed with Biodentine. The teeth capped with gutta-percha and restored with silver amalgam served as positive control, whereas untreated teeth served as negative control. Pulpal responses and coronal sealing were evaluated after 14 or 21 days. Data was statistically analyzed by the Kruskal-Wallis and Dunn's post hoc tests (p<0.05). Biodentine and MTA presented satisfactory results, showing a milder inflammatory response (p<0.0001) and more pronounced formation of mineralized barrier (p<0.0001) compared to the teeth capped with gutta-percha. As a restorative material, Biodentine kept coronal sealing in only 37.5% of the samples. Biodentine showed favorable properties in vital pulp therapy, being similar to MTA. However, it was not effective in protecting dental pulp from microleakage during the experimental period.

Abstract: The purpose of this manuscript was to re-discuss apical periodontitis, apical biofilm, and its possible relationship with dendritic cells (DC). DCs are potent regulators of the immune system and their function is divided into three categories that involve the presentation of antigens: the presentation of antigens and activation of T cells; a not well established category suggested that DCs induce and maintain immunological tolerance; and the maintenance of the immune memory in conjunction with B cells. DCs in periapical inflammatory lesions are composed of at least two subpopulations that can be distinguished on the basis of ultrastructure and phenotype. These populations might differ in lineage, state of maturation, differentiation, activation, and/or function. The authors hereby analyzed the root apexes of teeth under SEM, after performing apicoectomy due to the failure of conventional endodontic treatment. Microbial biofilm with multispecies and areas of resorption with the presence of Howship lacunae, and images suggestive of denditric cells could be observed. The presence of DCs in periapical lesion could be an indication of the severity of the lesion, with a constant presence of antigen in the periradicular region.

Abstract The aim of this study was to evaluate whether the modification in the silver component is capable of providing GuttaFlow 2 with antibacterial activity against Enterococcus faecalis compared with epoxy resin-based (AH Plus) and zinc oxide and eugenol-based (Endofill) sealers. The antibacterial activity was evaluated using a reference strain of E. faecalis (ATCC 29212). Freshly mixed sealers were subjected to the agar diffusion test (ADT), while the direct contact test (DCT) was performed after materials setting. ADT results were obtained through measurements, in millimeters, of the inhibition zones promoted by the materials, using a digital caliper. In DCT, values of CFU/mL promoted by the three sealers were compared in three experimental periods (1 min, 1 h, and 24 h). The data were analyzed using Kruskal-Wallis and Dunn post-hoc tests (p < 0.05). In both ADT and DCT, GuttaFlow 2 presented no effect against E. faecalis, while Endofill and AH Plus showed similar inhibition zones. Endofill was the only material capable of reducing bacterial growth in DCT. In conclusion, modifications in the silver particle of GuttaFlow 2 did not result in a sealer with antibacterial effect against E. faecalis.

O presente estudo teve como objetivo avaliar a influência das seguintes soluções irrigadoras na microdureza da dentina do canal radicular: hipoclorito de sódio a 2% (NaOCl2), hipoclorito de sódio a 5% (NaOCl5), água superoxidada (Sterilox(r) 400 ppm - Sx) e EDTA a 17% (E). Oitenta raízes de incisivos bovinos foram divididas aleatoriamente em 8 grupos (n=10): NaOCl2, NaOCl5, Sx e NaOCl2 + E, NaOCl5 + E, Sx + E (associados ao E como irrigante final por 5 min), E isolado e água destilada (H2Od), como controle negativo. O preparo dos canais radiculares foi realizado com instrumentos manuais, usando um dos protocolos de irrigação por 30 min. A seguir, 5 mm do terço cervical de cada amostra foram cortados perpendicularmente e submetidos ao teste de microdureza de Vickers, em dois pontos, um aproximadamente 500-1000 µm da luz do canal radicular (distância 1), e o outro aproximadamente 500-1000 µm da superfície externa da raiz (distância 2). Os dados foram analisados pelos testes de Wilcoxon e Kruskal-Wallis com um nível de significância de 5%. Os valores de microdureza na distância 1 foram significativamente menores do que na distância 2 para todos os grupos, exceto NaOCl5 e NaOCl5 +E (p>0,05). O EDTA mostrou os menores valores de microdureza. No entanto, não foi detectada diferença estatisticamente significativa entre os grupos na distância 1 e o EDTA foi significativamente diferente apenas do Sx na distância 2. Pode-se concluir que todas as soluções testadas mostraram menor microdureza na camada de dentina mais superficial do canal radicular em comparação aos valores encontrados próximo à superfície radicular externa, exceto NaOCl5 e NaOCl5 + E; o EDTA promoveu menor microdureza em comparação ao Sterilox(r) neste ponto.

The present study aimed to evaluate the influence of the following irrigating solutions on the microhardness of root canal dentin: 2% sodium hypochlorite (2NaOCl), 5% sodium hypochlorite (5NaOCl), super-oxidized water (400 ppm Sterilox - Sx) and 17% EDTA (E). Eighty roots from bovine incisors were randomly divided into 8 groups (n=10): 2NaOCl, 5NaOCl, Sx, and 2NaOCl + E, 5NaOCl + E, Sx + E (associated with E as final irrigant for 5 min), E solely and distilled water (dH2O) as the negative control. Root canal preparation was performed by hand instruments, using one of the irrigation protocols for 30 min. Then, 5 mm of the cervical root third were cut out from each sample and subjected to the Vickers microhardness test, at two points, one at approximately 500-1000 µm from the root canal lumen (distance 1), and the other at approximately 500-1000 µm from the external root surface (distance 2). Data were analyzed by Wilcoxon and Kruskal-Wallis tests at 5% significance level. Microhardness values at distance 1 were significantly lower than those at distance 2 for all groups, except 5NaOCl and 5NaOCl + E groups (p>0.05). EDTA showed the lowest microhardness values. However, no statistically significant difference was detected among groups at distance 1 and EDTA was significantly different only from Sx at distance 2. In conclusion, all tested solutions showed lower microhardness at the most superficial root canal dentin layer compared to the one found near the external root surface, except 5NaOCl and 5NaOCl + E; EDTA promoted lower microhardness values in comparison to Sterilox at this site.

ABSTRACT Ideally root canal irrigants should have, amongst other properties, antimicrobial action associated with a lack of toxicity against periapical tissues. Sodium hypochlorite (NaOCl) is a widely used root canal irrigant, however it has been shown to have a cytotoxic effect on vital tissue and therefore it is prudent to investigate alternative irrigants. Sterilox's Aquatine Alpha Electrolyte® belongs to the group of the super-oxidized waters; it consists of a mixture of oxidizing substances, and has been suggested to be used as root canal irrigant. Super-oxidized waters have been shown to provide efficient cleaning of root canal walls, and have been proposed to be used for the disinfection of medical equipment. OBJECTIVE: To compare the antimicrobial action against Enterococcus faecalis of NaOCl, Optident Sterilox Electrolyte Solution® and Sterilox's Aquatine Alpha Electrolyte® when used as irrigating solutions in a bovine root canal model. METHODOLOGY: Root sections were prepared and inoculated with E. faecalis JH2-2. After 10 days of incubation the root canals were irrigated using one of three solutions (NaOCl, Optident Sterilox Electrolyte Solution®and Sterilox's Aquatine Alpha Electrolyte®) and subsequently sampled by grinding dentin using drills. The debris was placed in BHI broth and dilutions were plated onto fresh agar plates to quantify growth. RESULTS: Sodium hypochlorite was the only irrigant to eliminate all bacteria. When the dilutions were made, although NaOCl was still statistically superior, Sterilox's Aquatine Alpha Electrolyte® solution was superior to Optident Sterilox Electrolyte Solution®. CONCLUSIONS: Under the conditions of this study Sterilox's Aquatine Alpha Electrolyte® appeared to have significantly more antimicrobial action compared to the Optident Sterilox Electrolyte Solution® alone, however NaOCl was the only solution able to consistently eradicate E. faecalis in the model.

The purpose of this work was to develop a model system to study antimicrobial strategies in endodontic biofilms. Enterococcus faecalis suspension was colonized in 10 human root canals. Five milliliters of Brain Heart Infusion (BHI) were mixed with 5 mL of the bacterial inoculums (E. faecalis) and inoculated with sufficient volume to fill the root canal during 60 days. This procedure was repeated every 72 h, always using 24-h pure culture prepared and adjusted to No. 1 MacFarland turbidity standard. Biofilm formation was analyzed by scanning electron microscopy (SEM). E. faecalis consistently adhered to collagen structure, colonized dentin surface, progressed towards the dentinal tubules and formed a biofilm. The proposed biofilm model seems to be viable for studies on antimicrobial strategies, and allows for a satisfactory colonization time of selected bacterial species with virulence and adherence properties.

The purpose of this paper is to discuss critically the antibacterial efficacy of intracanal medicaments on bacterial biofilm. Longitudinal studies were evaluated by a systematic review of English-language articles retrieved from electronic biomedical journal databases (MEDLINE, EMBASE, CENTRAL) and handsearching records, using different matches of keywords for root canal biofilm, between 1966 and August 1st, 2007. The selected articles were identified from titles, abstracts and full-text articles by two independent reviewers, considering the tabulated inclusion and exclusion criteria. Disagreements were resolved by consensus. The search retrieved 91 related articles, of which 8.8% referred to in vivo studies demonstrating the lack of efficacy of endodontic therapy on bacterial biofilm. Intracanal medicaments were found to have a limited action against bacterial biofilm.

The aim of this study was to analyze the buccal tissue responses of Wistar rats to 2% chlorhexidine solution, calcium hydroxide and the association of both products. For this purpose, 30 specimens were randomly implanted in the filtrum of the four upper and lower hemiarches with a polyethylene tube containing one of the following substances: 2% chlorhexidine solution, calcium hydroxide and 2% chlorhexidine solution (test groups); calcium hydroxide and distilled water and distilled water (control groups). Ten rats each were distributed according to time interval of evaluation at 7, 15 and 30 days. The histological sections were stained with Harris hematoxylin and eosin. Analysis was performed with an optical microscope at x100, x200 and x400 magnifications by an expert examiner blinded to the materials. The sections were classified by scores attributed to inflammatory events and by a ranking determined according to the severity of the inflammation. The results of the inflammatory events and severity ranking were submitted to the Kruskal-Wallis test at a 0.05 level of significance. No statistically significant difference occurred among the tested materials; however, all materials showed a decreased of severity with respect to longer time intervals.

OBJETIVO: O objetivo deste estudo foi avaliar, in vitro, a qualidade do preenchimento de canais radiculares curvos com a pasta de hidróxido de cálcio [Ca(OH)2] Ultracal (Ultradent), associada ou não a cones de guta-percha contendo hidróxido de cálcio (Calcium Hydroxide Plus PointsTM, Roeko). MATERIAL E MÉTODOS: Cento e vinte raízes de dentes humanos extraídos, aleatoriamente distribuídas em 3 faixas de curvatura (leve - 0 a 14º; moderada - 15º a 29º; severa > 30º) foram utilizadas. Após o preparo químico-mecânico, as raízes foram divididas em 4 grupos (n=30) de acordo com o método de aplicação da medicação intracanal: grupo 1 - aplicação da pasta de Ca(OH)2 com espiral de lentulo; grupo 2 - aplicação da pasta de Ca(OH)2 com espiral de lentulo, seguida da introdução de um cone de Ca(OH)2; grupo 3 - aplicação da pasta de Ca(OH)2 com a ponta NavitipTM (fornecida com o Sistema Ultracal); grupo 4 - aplicação da pasta de Ca(OH)2 com a ponta NavitipTM seguida da introdução de um cone de Ca(OH)2. As raízes foram diafanizadas e avaliadas quanto à qualidade do preenchimento do terço apical dos canais por um examinador calibrado. Os espécimes foram examinados em lupa estereoscópica e classificadas por escores de 1 a 4 (desde preenchimento inadequado até preenchimento total dos canais). Os resultados foram comparados através da análise de variância e teste post hoc de Duncan com nível de significância de 5%. RESULTADOS: Não se observaram diferenças estatisticamente significantes (p>0.05) entre os graus de curvatura dos grupos 1, 3 e 4 quanto ao preenchimento dos canais. A curvatura severa no grupo 2 apresentou significância limítrofe (p=0,05). Os grupos que associaram pasta e cones de Ca(OH)2 (2 e 4) apresentaram melhor preenchimento apical em relação aos demais grupos, porém essa diferença foi estatisticamente significante (p<0,001) somente para as raízes com curvatura severa. CONCLUSÃO: De acordo com os resultados deste estudo, o grau de curvatura não influenciou na qualidade do preenchimento. As técnicas que utilizaram cones de guta percha contendo Ca(OH)2 promoveram um melhor preenchimento do terço apical em canais radiculares com curvatura severa.

PURPOSE: The aim of this study was to evaluate, in vitro, the quality of calcium hydroxide [Ca(OH)2] paste filling (Ultracal, Ultradent) associated or not with Ca(OH)2-containing gutta-percha points (Calcium Hydroxide Plus PointsTM, Roeko) in curved root canals. MATERIAL AND METHODS: One hundred and twenty roots of extracted human teeth, randomly divided into three curvature ranges (mild - 0 to 14º; moderate - 15º to 29º; severe - >30º) were used. After chemomechanical preparation, the roots were assigned to 4 groups (n=30), according to the technique of intracanal dressing placement: group 1 - Ca(OH)2 paste was applied with a lentulo spiral; group 2 - Ca(OH)2 paste was applied with a lentulo spiral and a Ca(OH)2 point was inserted into the canal; group 3 - Ca(OH)2 paste was applied with a NavitipTM tip (supplied with Ultracal system); group 4 - Ca(OH)2 paste was applied with a NavitipTM tip and a Ca(OH)2 point was inserted into the canal. The roots were cleared and the quality of apical third filling was assessed by a calibrated experienced examiner. The specimens were examined under stereomicroscopy and scored 1 to 4 (i.e., from inadequate to complete root canal filling). The results were analyzed statistically by ANOVA and Duncan's post hoc test at 5% significance level. RESULTS: There were no statistically significant differences (p>0.05) among the curvature degrees in groups 1, 3 and 4. Severely curved roots in group 2 presented bordering significance (p=0.05). The groups that associated the use of Ca(OH)2 paste and points (2 and 4) showed better apical filling than the other groups, but this difference was statistically significant (p<0.001) only for roots with severe curvature. CONCLUSION: According to the results of this study, the curvature degree did not influence the quality of filling. The techniques that used Ca(OH)2-containing gutta-percha points yielded better filling of the apical third in roots with severe curvature.