Effect of passive ultrasonic activation on microorganisms in primary root canal infection: a randomized clinical trial

Objective: This clinical study sought to evaluate the effectiveness of passive ultrasonic activation (PUA) in eliminating microorganisms in primary endodontic infection (PEI) after instrumentation of root canals using microbiological culture and checkerboard DNA-DNA hybridization. Methodology: Twenty root canals with PEI and apical periodontitis were selected. The root canals were instrumented and then randomly divided into 2 groups, according to the irrigation method: PUA and conventional needle irrigation (CNI). Microbiological samples were collected before instrumentation (S1), after instrumentation (S2) and after irrigation with 17% EDTA (S3). The samples were subjected to anaerobic culture technique and checkerboard DNA-DNA hybridization analysis. Results: A statistically significant difference was found between CNI (23.56%) and PUA (98.37%) regarding the median percentage values for culturable bacteria reduction (p<0.05). In the initial samples, the most frequently detected species was S. constellatus (50%), and after root canal treatment was E. faecalis (50%). Conclusion: Both treatments significantly decreased the number of bacterial species compared with the initial sample. However, no statistical difference in the total microbial load between PUA and CNI groups was detected. The number of cultivable anaerobic bacteria reduced significantly using PUA, and the bacterial composition and number of bacterial species after using either CNI or PUA was similar

In vitro Evaluation of the Antimicrobial Effect of N-acetylcysteine and Photodynamic Therapy on Root Canals Infected with Enterococcus faecalis

Introduction: This study aimed to evaluate the effectiveness of N-acetylcysteine (NAC), photodynamic therapy (PDT) and NAC with supplemental PDT in optimizing the removal of bacteria from infected dentinal tubules of root canals infected with Enterococcus (E.) faecalis biofilm. Methods and Materials: Eighty human teeth were randomly divided into 5 groups (n=16) according to the intracanal medication used: saline solution (control); calcium hydroxide (CH); NAC; PDT; NAC+PDT. Ten samples from each group were prepared for microbiological culture analysis (CFU/mL) and were inoculated with E. faecalis suspension for 21 days for biofilm development; the other six samples from each group were prepared for scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) and submitted to a 5-days contamination protocol including eight centrifugation cycles on every other day for dentinal tubules infection. For antimicrobial activity analysis by microbiological culture, the root canals were contaminated with E. faecalis biofilm, instrumented and then medicated according to the experimental groups. Three samples were collected from the root canals: after 21-days of contamination, immediately after the instrumentation and 14-days after the medication according to the experimental groups. The morphology of E. faecalis biofilm on the root canal walls and bacterial cells viability were assessed by means of SEM and CLSM, respectively. One-way ANOVA and Repeated Measures ANOVA tests were used to analyze the obtained data statistically. Results: CFU/mL analysis showed that CH, NAC and NAC+PDT promoted greater antibacterial activity with statistically significant difference compared to saline solution and PDT (P<0.0001). However, saline solution and PDT were statistically similar. Illustrative images by SEM confirmed partially the CFU/mL results. CLSM showed that all groups were effective eliminating E. faecalis except for the saline solution group. Conclusions: Based on this in vitro study NAC was bactericidal against E. faecalis biofilms regardless PDT stimulation, presenting similar antimicrobial activity to CH

Terapia endodôntica em dentes imaturos : da apicificação ao procedimento de revitalização/revascularização pulpar - revisão de literatura

Devido a uma crescente busca por melhores resultados e um menor tempo clínico no tratamento de canais radiculares, a pesquisa na área da endodontia tem sido amplamente explorada, e não poderia ser diferente quando se trata do tratamento de dentes permanentes de ápice incompleto. A engenharia tecidual tem ganhado campo dentre as especialidades médicas, assim como na odontologia, demonstrando um grande número de investigações e publicações a respeito do tema. Faz-se necessário entender o motivo da atenção dada ao tratamento em dentes com necrose pulpar e rizogênese incompleta e quais são os protocolos utilizados atualmente, pois este tratamento ainda é um desafio, uma vez que não houve completa formação do ápice radicular e, consequentemente, a modelagem e posterior obturação do canal podem tornar-se insatisfatórias. Atualmente, as alternativas de tratamento vão desde a tradicional apicificação até os métodos de revitalização /revascularização, com emprego de medicações e, mais recentemente, o estudo com os scaffolds, que têm como função fornecer suporte ao crescimento celularDue to a growing concern for better results and a smaller clinical time in the treatment of root canals. Research in Endodontics has been widely explored and this could not be different when we are dealing with the treatment of incomplete apex permanent teeth. Tissue Engineering has gained space among medical areas as well as in Dentistry, showing a great number of investigations and publications about the theme. Therefore, it is important that we understand the reason of such attention given to the treatment of teeth with pulp necrosis and incomplete rhizogenesis and which protocols are currently being used, because it is still a challenge, once there was no complete formation of the root canal, and consequently, the casting and posterior filling of the canal can be unsatisfactory. Nowadays treatment alternatives range from traditional apexification to methods of revitalization/revascularization, with the use of medications and, more recently, with the use of scaffolds, that have the function of supplying support for celular growt

Volumetric Evaluation of Voids and Gaps of Different Calcium-Silicate Based Materials Used in Furcal Perforations: A Micro-CT Study

This study aimed at evaluating volumetrically gaps and voids of calcium-silicate based materials of different generations and handling properties (BC—Endosequence BC RRM-Fast Set Condensable Putty, MTA—ProRoot MTA, and BIO—Biodentine) in simulated furcal perforations in an ex vivo setup by microcomputed tomography (Micro-CT) analysis. Thirty-six extracted human mandibular molars with sound furcation areas were selected. Standardized perforations were created in the furcation area of the pulp chamber using #4 diamond burs. The specimens were randomly assigned to three groups (BC, MTA and BIO; n = 12). Samples were then scanned (SkyScan 1172; Bruker-microCT, Kontich, Belgium), and three-dimensional (3D) images reconstructed. The relative volume of gaps (VG%) and voids (VV%) present on each material was calculated. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey’s HSD test (p < 0.05). Mean VG% for BC, MTA, and BIO groups were, respectively, 0.513%, 1.128%, 1.460%, with BC presenting statistically (p < 0.05) fewer gaps formation than the other groups. Mean VV% were, respectively, 0.018%, 0.037%, and 0.065%. The was no statistical difference regarding VV%. There were no gap-free and void-free samples. BC group had the lowest VG% among the groups with a significant statistical difference (p < 0.05)