Effectiveness of root canal debris removal using passive ultrasound irrigation with chlorhexidine digluconate or sodium hypochlorite individually or in combination as irrigants.

AIM: The aim of this in vitro study was to evaluate the cleaning capacity of different auxiliary chemical substances energized with ultrasound in radicular dentin using morphologic analysis. METHODS AND MATERIALS: Twenty-eight single-canal, mandibular incisors were prepared with the Hero 642 canal preparation system following the sequence: 25/12, 30/06, 35/02, and 40/02, 1 mm from the apex. The specimens were then divided into four groups of seven teeth. During biomechanical preparation the teeth were irrigated with 2 ml of distilled water between files. Each group of specimens (n=7) received a final irrigation with 100 ml of the following irrigants that were activated with ultrasound for 3 minutes: Group 1- distilled water; Group 2- 0.2% chlorhexidine digluconate (CHX); Group 3- 2.5% sodium hypochlorite (NaOCl); and Group 4-the filtrate obtained after combining 0.2% CHX and 2.5% NaOCl. The apical portions of the root canals from each group were then submitted to histological processing and analyzed using optical microscopy. RESULTS: Results showed statistical differences between the groups (p<0.01). Groups 1 and 2 (distilled water and 0.2% CHX respectively) were statistically similar in terms of a greater amount of debris, whereas 2.5% NaOCl and the filtrate were more efficient in removal of debris. CONCLUSION: There is no additional benefit in terms of debris removal from root canal walls by irrigating with the filtrate obtained from the combination of NaOCl and CHX when compared to using NaOCl alone. CLINICAL SIGNIFICANCE: The findings of this study suggest the time and expense of preparing and using a combination of NaOCl and CHX is not warranted compared to using NaOCl alone for root canal irrigation.

In vitro evaluation of endodontic debris removal as obtained by rotary instrumentation coupled with ultrasonic irrigation.

The cleaning capacity of rotary Ni-Ti instrumentation using Profile GT files, coupled with irrigation energised by ultrasound, was evaluated. Thirty-six human mandibular incisors were instrumented in vitro using the crown-down technique with the Profile GT system to 1 mm from the anatomical apex to a size 30.04 taper file. The instrumented teeth were then divided randomly into four groups where various final irrigations were used: Group I: 100 ml of 1% NaOCl with a Luer-Lok syringe (control group); Group II, Group III and Group IV: final irrigation with 100 ml of 1% NaOCl energised by ultrasound for 1, 3 and 5 min, respectively. After biomechanical preparation, the apical thirds of the roots were submitted to histological processing and examination. The specimens were analysed at 40x magnification and the images submitted to morphometric analysis with an integration grid. anova showed a statistically significant difference (P < 0.01) between the irrigation techniques. Group I (Luer-Lok syringe) showed the highest percentage of debris (35.81 +/- 4.49) and was statistically different from the other groups energised by ultrasound: Group II (27.28 +/- 4.49), Group III (24.39 +/- 5.72) and Group IV (18.46 +/- 5.25). It was concluded that rotary instrumentation using Ni-Ti files associated with final irrigation of 1% NaOCl energised by ultrasound leads to better debris removal from the apical third of mesio-distally flattened root canal.

Condições atípicas da anatomia de canais radiculares em pré-molares inferiores / Atypical situations in root canals anatomy of human mandibular premolars

O conhecimento da anatomia interna de dentes que terão seus condutos radiculares tratados endodônticamente é de fundamental importância para o sucesso do tratamento e do prognóstico desses dentes. Neste estudo, foram discutidas as variações morfológicas que podem ocorrer em relação ao número de canais radiculares presentes no grupo dental dos pré-molares inferiores, bem como os métodos mais eficazes de diagnosticar a presença dessas variações, a fim de ter um diagnóstico mais preciso quanto ao número de canais a serem tratados. Portanto, foi relatado um caso clínico de tratamento endodôntico de um pré-molar inferior com 4 condutos e demonstrados alguns casos de endodontia em pré-molares inferiores com 1, 2 e 3 condutos

The knowledge of the teeth internal anatomy that will receive endodontic treatment is very important for the success of the treatment and prognosis of those teeth. In this study, the morphological variations that may occur in relation to the number of root canals present in the premolar mandibular teeth group were discussed, as well as the most efficient methods to diagnose the existence of these variations, in order to have a clearer diagnosis of the number of root canals to be treated. A case of an endodontic treatment of a mandibular premolar with 4 root canals was reported and some cases of endodontic treatment in mandibular premolars with 1, 2 and 3 root canals were shown

Histological analysis of the cleaning capacity of nickel-titanium rotary instrumentation with ultrasonic irrigation in root canals.

This study evaluated, histologically and morphometrically, the cleaning capacity of rotary instrumentation in root canals using the Profile system with ultrasonic irrigation. Twelve single-rooted mandibular incisors were divided randomly into three groups according to the irrigation method tested. The canals in the teeth were instrumented using Orifice Shapers, taper 0.6 and 0.4 in the cervical third, and up to a #35 file in the apical third. One per cent sodium hypochlorite was used as the irrigating solution. Group I: canals were irrigated with 5 ml of solution, using a Luer-Lok syringe, between each file. Group 2: canals were irrigated with the solution and instrumented using ultrasound for I min between each file. Group 3: canals were irrigated with 5 ml of solution with Luer-Lok syringe, between each file, and final irrigation using ultrasound for 3 min. After chemo-mechanical preparation, the apical thirds of the teeth were submitted for histological processing. Morphometric analysis was performed using an optical microscope with 40x magnification and a grid. The results showed statistical difference at the 5% level between the methods used for irrigation. Rotary instrumentation with Profile system NiTi files and ultrasonic irrigation for 3 min was more effective in cleaning root canals when the different methods were compared.