ABSTRACT
Objective: This study evaluated the cleaning efficacy of the rotary nickel–titanium Mtwo® by means of optical microscopy in oval‑shaped root canals and compared refinement influence using ultrasonic files or Hedströem files. Materials and Methods: Twenty mandibular incisors were accessed, included in epoxy resin blocks, and cut transversely at 3, 6, and 9 mm from the apex. Teeth were instrumented using rotary nickel–titanium Mtwo. Digital images of the root cross sections were obtained before and after instrumentation with a digital camera attached to an optical microscope. Subsequently, samples were randomly divided into two groups for refinement. Group I was refined using ultrasonic files #30 and group II with Hedströem files #30. Final digital images of cross sections after refinement were captured and analyzed. The boundaries for the uninstrumented perimeter were measured by the software ImageTool 3.0. The data obtained were statistically analyzed by analysis of variance (ANOVA) and t‑test. Results: Mtwo instrumentation produced 41.48% of the uninstrumented perimeter. The final refinement using Hedströem and ultrasonic files decreased the uninstrumented perimeter. Significant differences (t‑test, P = 0.00) were found at the three thirds after the final refinement, except for the apical third that was enhanced by Hedströem file. However, there was no statistical difference between the two refinement techniques used (P > 0.05). Mtwo instrumentation was not capable of cleaning and shaping the entire perimeter of the root canals walls. Conclusions: The final refinement, either with ultrasonic files or with Hedströem files, resulted in significantly less uninstrumented perimeter.
Subject(s)
Dental Alloys , Dental Pulp Cavity/therapy , Microscopy/methods , Nickel , Root Canal Preparation/instrumentation , Root Canal Preparation/methods , Rotation , TitaniumABSTRACT
Introduction and objective: The aim of this in vitro study was to evaluate the cleaning and shaping efficacy of rotary nickel-titanium ProTaper® instrumentation in oval canals and the influence of ultrasonic irrigation on the final refinement. Material and methods: Twenty mandibular molars were accessed and divided in two groups. Only distal roots with oval canals were used. Group I was instrumented using only rotary nickel-titanium ProTaper® instruments. Group II received the same preparation followed by refinement with 3 minutes of ultrasonic passive irrigation. After preparation, the distal roots were sectioned for histological processing. Coronal, middle and apical thirds were analyzed. Uninstrumented perimeter in each third was measured by the software Image tool 3.0. Results: The percentage of uninstrumented perimeter was calculated for each third of each root and average percentage was calculated for each third in both groups. Statistical analysis was performed with t-test through the software SPSS 11.0.1 for Windows. The level of significance was set at 1%. Group I showed higher percentage of uninstrumented perimeter in all thirds. Group II, which received ultrasonic irrigation showed better results in all thirds (p < 0.01). Comparing the three thirds in the same group, no statistically significant differences were found (p > 0.05). Conclusion: Under the conditions of this ex vivo study, the three minutes use of ultrasonic irrigation after rotary instrumentation resulted in significantly more instrumented walls in the distal roots of mandibular molars.
ABSTRACT
O objetivo deste estudo foi avaliar a influência de duas soluções irrigadoras antibacterianas na capacidade de vedamento do MTA e do cimento Portland brancos utilizados como material obturador de perfurações de furca, em quarenta e seis molares humanos extraídos. Após a realização das perfurações na furca realizadas com brocas esféricas # 2, os dentes foram divididos em quatro grupos de dez dentes, sendo os seis dentes restantes divididos em grupos controle positivo e negativo. Os grupos 1 e 2 foram irrigados com hipoclorito de sódio 5,25% e obturados com MTA e cimento Portland respectivamente. Os grupos 3 e 4 foram irrigados com clorexidina gel 2% e também obturados com MTA e cimento Portland respectivamente. Após a obturação das perfurações, os espécimes foram montados em aparatos e inoculados com uma suspensão de Enterococcus faecalis por 61 dias. Os resultados foram submetidos ao teste de Log-rank que demonstrou não haver diferença estatística significativa entre os quatro grupos (p < 0,05). Sob as condições experimentais deste trabalho, a clorexidina gel 2% e o hipoclorito de sódio 5,25% não prejudicaram a capacidade de vedamento do MTA assim como do cimento Portland.
The aim of this study was to evaluate the effect of two endodontic irrigation solutions on the ability of white mineral trioxide aggregate (MTA), compared to Portland cement, to seal furcal perforations in 46 extracted human mandibular molars. Furcal perforations were made in the center of the pulp chamber floor using a high-speed round bur #2. The teeth were randomly divided into four experimental groups of 10, with the remaining six teeth used as positive and negative groups. Experimental groups 1 and 2 were irrigated with 5,25% sodium hypoclorite, and then repaired with MTA and Portland cement, respectively. Experimental groups 3 and 4 were irrigated with 2% chlorhexidine gluconate gel, and then repaired with MTA and Portland cement respectively. After placing the repair materiais into the perforations, the specimens were mounted in an apparatus and inoculated with a suspension of Enterococcus faecalis for 61 days. The leakage data were analysed statistically by a log-rank test (p < 0,05). There was no statistically significant difference among the four groups. Under the conditions of this study, 2% chlorhexidine gluconate gel and 5,25% sodium hypoclorite did not adversely affect the sealing ability of MTA. Portland cement and MTA demonstrated similar ability to seal furcal perforations.
Subject(s)
Humans , Male , Female , Chlorhexidine , Endodontics , Enterococcus faecalis , Sodium HypochloriteABSTRACT
O objetivo deste estudo foi avaliar a influência de duas soluções irrigadoras antibacterianas na capacidade de vedamento de duas marcas comerciais de MTA utilizados como materiais obturadores de perfurações de furca, em 70 molares humanos extraídos. As perfurações criadas artificialmente foram irrigadas com hipoclorito de sódio 5% ou clorexidina gel 2% e obturados com MTA (de dois fabricantes diferentes). Os dentes foram submersos em Rodamina B 2% e, posteriormente, clivados longitudinalmente para que a infiltração fosse verificada e medida através de um perfilômetro com micrômetro digital. Os resultados submetidos aos testes estatísticos F de ANOVA (p<0,05) e t de Tukey (p<0,05) demonstraram maior infiltração nos grupos da clorexidina, não havendo diferença estatisticamente significativa entre o MTA Agelus® e o Pro Root MTA®.
The aim of this study was to evaluate the influence of two antibacterial irrigant solutions in the MTA sealing ability when used as perforation of furcation sealer in 70 extracted human molars. The artificially created perforations were irrigated with 5% NaOCl and 2% chlorhexidine gel and sealed with MTA (Angelus and Pro Root MTA). The teeth were sunk in 2% Rodamina B dye and later longitudinally sectioned. The microleakage was length by means of a profile projector and a digital micrometer. The results were submitted to statistical analyses with One-way ANOVA (p<0.05) and Tuckey test (p<0.05) that showed greater microleakage means in the chlorhexidine groups and no significant statistical difference between MTA Angelus and Pro Root MTA.