Biological and chemical properties of 2-in-1 calcium-chelating and antibacterial root canal irrigants.

OBJECTIVES: To evaluate the capacity of canal wall smear layer removal, precipitation caused by irrigant interaction, antibacterial activity and cytotoxicity of three 2-in-1 root canal irrigating solutions. METHODS: Forty single-rooted teeth were mechanically instrumented and irrigated with QMix, SmearOFF, Irritrol or 0.9% saline. Each tooth was evaluated for smear layer removal using scanning electron microscopy. Precipitation after interaction of the irrigating solutions with sodium hypochlorite (NaOCl) was evaluated with 1H nuclear magnetic resonance and mass spectroscopy. Confocal laser scanning microscopy was used to evaluate the antimicrobial activity of the irrigants against Enterococcus faecalis biofilms. Neutral red and clonogenic assays were performed on Chinese hamster V79 cells to evaluate the short-term and long-term cytotoxicity of the irrigants. RESULTS: There was no significant difference between QMix and SmearOFF in eliminating smear layers from the coronal-third and middle-third of the canal spaces. In the apical-third, SmearOFF removed smear layers effectively. Irritrol incompletely removed smear layers from all the canal-thirds. When mixed with NaOCl, precipitation was evident only with Irritrol. QMix demonstrated a higher E. faecalis cell death percentage and a smaller biovolume. SmearOFF exhibited a larger decrease in biovolume compared with Irritrol, although Irritrol had a higher death percentage. Irritrol was more cytotoxic than the other irrigants on a short-term interval. In terms of long-term cytotoxicity, both Irritrol and QMix were cytotoxic. CONCLUSION: QMix and SmearOFF performed better in smear layer removal and antimicrobial activity. QMix and Irritrol were cytotoxic when compared to SmearOFF. Irritrol was associated with precipitation after interacting with NaOCl. CLINICAL SIGNIFICANCE: Evaluation of the smear layer removal capability, antibacterial activity and cytotoxicity of 2-in-1 root canal irrigants is necessary to ensure that they are safe to use during root canal treatment.

Conservative management of tooth wear: A case series.

Tooth wears in general term means loss of tooth structure. Tooth loss increases with age and thus causes difficulty in chewing and increased sensitivity. Wear facets on the occlusal surface are subjected to high occlusal stresses leading to repeated dislodgment of the restoration. This article presents the use of bonded amalgam as a restorative material for restoring localized occlusal wear facets.

Influence of particulate alkaline biomaterial remnants in dentin on the adhesion of two resin-based bonding systems.

To study aimed to evaluate the influence of infiltrated alkaline biomaterials on the bond strength of composite obtained with etch and rinse and universal adhesive systems. Coronal dentin of extracted human molars was exposed and infiltrated with calcium hydroxide, MTA, or bioactive glass 45S5 powder. Non-infiltrated dentin specimens served as controls. Subsequently, dentin was either acid-etched or not, and remaining alkali content was measured by pH induction in water. Shear bond strength of an etch-and rinse system (Adper Single Bond 2) on etched dentin was then compared to that of a universal counterpart (Single Bond [(Scotchbond) Universal] by the same manufacturer. Data was compared between groups using one-way ANOVA and Tukey's HSD. On sound dentin, the etch-and-rinse system adhered stronger than the universal system (p < .05). All particles rendered the dentin alkaline. Acid etching reduced the alkali content in the infiltrated dentin. However, bond strength values were stronger with the universal system without etching than with the etch-and rinse counterpart, which lost more than 60% of its adhesiveness. The universal adhesive system was less susceptible to alkaline contamination of the dentin than the etch-and-rinse counterpart. Based on the similar composition of the two systems under investigation, this is likely to the due to its 10-MDP component.

Evaluation of various irrigation activation systems to eliminate bacteria from the root canal system: A randomized controlled single blinded trial.

OBJECTIVE: To evaluate the effect of NaOCl irrigant activation using passive ultrasonic activation, F-files, XP-endo Finisher files and or needle irrigation alone on the reduction of intracanal bacteria from root canals in teeth undergoing root canal treatment. METHODS: Eighty patients with asymptomatic apical periodontitis were randomly divided into four groups. Access cavities were prepared and pre-treatment samples were taken (S1). Canals were then prepared and post-instrumentation samples (S2) taken. NaOCl was then activated with the various irrigant activation systems and post-irrigation samples (S3) taken. The samples were processed and colony forming units (CFUs) of bacteria were determined. The reduction in CFUs among the experimental groups were analysed using the Kruskal Wallis test and pairwise comparisons with the Mann-Whitney test. The Friedman test was used to compare the differences in the reduction of CFUs within the groups. RESULTS: Overall, for all groups there was a significant reduction in the CFUs from S1 to S2 (P < 0.05) and from S2 to S3 (P < 0.05). Both XP-endo Finisher and passive ultrasonic activation techniques were associated with the greatest reduction in CFUs with no significant difference between them (P = 0.24). However, both were associated with significantly lower CFUs when compared to F-file activation and needle irrigation (P < 0.05). F-file activation reduced the CFUs significantly more compared to needle irrigation (P = 0.04). CONCLUSIONS: XP-endo Finisher file activation and passive ultrasonic activation were equivalent in terms of reduction in CFUs. F-file activation did not reduce the CFUs to the same extent as the XP-endo Finisher file and ultrasonic activation but reduced the CFUs more than needle irrigation. CLINICAL SIGNIFICANCE: The present study highlights the effect of new XP-endo Finisher file and passive ultrasonic activation in reducing the bacterial load from the root canal system which is important for the success of root canal treatment.

The efficacy of different irrigation protocols in removing tricalcium silicate-based sealers from simulated root canal irregularities.

OBJECTIVE: The aim of this study was to evaluate the efficacy of different irrigation protocols in removing two tricalcium silicate-based sealers from simulated root canal irregularities and root canal walls. MATERIAL AND METHODS: Root canals of 140 single-rooted teeth were instrumented. In one-half of each root, an apical groove was created. The samples were divided into two main groups (n = 70) based on the sealer used. In group 1, the grooves were filled with MTA Fillapex; in group 2, BioRoot RCS. The reassembled root halves were divided into six experimental and one control groups: 2.5% NaOCl-17% EDTA (Passive ultrasonic irrigation [PUI]), 5% NaOCl/9% DualRinse HEDP (PUI), 2.5% NaOCl-7% Maleic acid (PUI), 2.5% NaOCl-17% EDTA (Er:YAG laser activated irrigation [LAI]), 2.5% NaOCl/9% DualRinse HEDP (LAI), 2.5% NaOCl-7% Maleic acid (LAI), Distilled water (Control). Specimens were scored using SEM. The data were analysed using Kruskal-Wallis and Mann Whitney U tests. RESULTS: Maleic acid and DualRinse HEDP removed higher amounts of MTA Fillapex from the grooves compared to EDTA, when used with both activation methods (p < .001). CONCLUSIONS: Ultrasonically activated maleic acid or DualRinse HEDP can be an effective irrigation regimen in removing tricalcium silicate-based sealers.