Histological analysis of cleaning efficacy of hand and rotary instruments in the apical third of the root canal: A comparative study

Endodontic management of a tooth with apical overfilling and perforating external root resorption: A case report

Successful non-surgical orthograde retreatment of a tooth with external root resorption in apical third of root and overfilling material beyond the apical barrier which was diagnosed with the help of cone beam computed tomography (CBCT), was reported. Biodentine was used as the treatment of choice for obturation of resorption area.

Effect of QMix irrigant in removal of smear layer in root canal system: a systematic review of in vitro studies

Objectives

To evaluate the outcome of in vitro studies comparing the effectiveness of QMix irrigant in removing the smear layer in the root canal system compared with other irrigants.

Materials and Methods

The research question was developed by using Population, Intervention, Comparison, Outcome and Study design framework. Literature search was performed using 3 electronic databases PubMed, Scopus, and EBSCOhost until October 2019. Two reviewers were independently involved in the selection of the articles and data extraction process. Risk of bias of the studies was independently appraised using revised Cochrane Risk of Bias tool (RoB 2.0) based on 5 domains.

Results

Thirteen studies fulfilled the selection criteria. The overall risk of bias was moderate. QMix was found to have better smear layer removal ability than mixture of tetracycline isonomer, an acid and a detergent (MTAD), sodium hypochlorite (NaOCl), and phytic acid. The efficacy was less effective than 7% maleic acid and 10% citric acid. No conclusive results could be drawn between QMix and 17% ethylenediaminetetraacetic acid due to conflicting results. QMix was more effective when used for 3 minutes than 1 minute.

Conclusions

QMix has better smear layer removal ability compared to MTAD, NaOCl, Tubulicid Plus, and Phytic acid. In order to remove the smear layer more effectively with QMix, it is recommended to use it for a longer duration.

Scanning Electron Microscopic Evaluation of Residual Smear Layer Following Preparation of Curved Root Canals Using Hand Instrumentation or Two Engine-Driven Systems

Introduction:

In this experimental study, the amount of smear layer (SL) remnants in curved root canals after chemomechanical instrumentation with two engine-driven systems or hand instrumentation was evaluated.

Methods and Materials:

Forty-eight mesiobuccal roots of mandibular first molars with curvatures ranging between 25 and 35 degrees (according to Schneider’s method) were divided into three groups (n=16) which were prepared by either the ProTaper Universal file series, Reciproc single file system or hand instrumentation. The canals were intermittently irrigated with 5.25% NaOCl and 17% (ethylenediaminetetraacetic acid) EDTA, followed by distilled water as the final rinse. The roots were split longitudinally and the apical third of the specimens were evaluated under 2500× magnification with a scanning electron microscope (SEM). The mean scores of the SL were calculated and analyzed using the non-parametric Kruskal-Wallis and Mann-Whitney U tests.

Results:

The mean scores of the SL were 2.00±0.73, 1.94±0.68 and 1.44±0.63 µm for the ProTaper Universal, Reciproc and hand instrumentation, respectively. Mean score of SL was significantly less in the hand instrumentation group than the ProTaper (P=0.027) and Reciproc (P=0.035) groups. The difference between the two engine-driven systems, however, was not significant (P=0.803).

Conclusion:

The amount of smear layer in the apical third of curved root canals prepared with both engine-driven systems was similar and greater than the hand instrumentation technique. Complete cleanliness was not attained.

Comparison of the cleaning efficacy of EndoVac with conventional irrigation needles in debris removal from root canal. An in-vivo study

Aim and Objective:

The aims were to evaluate the root canal debris removal after irrigation with EndoVac system and to compare its efficacy with Max-i-Probe needles.

Materials and Methods:

Fifteen matched pairs of single canalled vital teeth with mature apices indicated for extraction were selected. After working length determination and biomechanical preparation, the teeth in the right quadrant were irrigated with EndoVac system and with Max-i-Probe needles in the left quadrant using 3% NaOCl and 17% ethylenediaminetetraacetic acid. Teeth were extracted and marked at 1 and 3 mm from working length and decalcified in Kristenson's solution. Stained histologic slides were observed under trinocular research microscope. Wilcoxon signed-rank test was used for statistical analysis. The statistical significance was set at P < 0.05 and the analysis was performed using SPSS version 11.0 software.

Results:

No statistical significant difference was found at 3 mm level between the groups. Group I had significantly less debris at 1 mm level.

Conclusion:

EndoVac performed better in removing debris from the apical thirds of root canals.

Effect of passive ultrasonic agitation during final irrigation on cleaning capacity of hybrid instrumentation

OBJECTIVES

To evaluate the effect of passive ultrasonic agitation on the cleaning capacity of a hybrid instrumentation technique.

MATERIALS AND METHODS

Twenty mandibular incisors with mesiodistal-flattened root shape had their crowns sectioned at 1 mm from the cementoenamel junction. Instrumentation was initiated by catheterization with K-type files (Denstply Maillefer) #10, #15, and #20 at 3 mm from the working length. Cervical preparation was performed with Largo bur #1 (Dentsply Maillefer) followed by apical instrumentation with K-type files #15, #20 and #25, and finishing with ProTaper F2 file (Denstply Maillefer). All files were used up to the working length under irrigation with 1 mL of 2.5% sodium hypochlorite (Biodynâmica) at each instrument change. At the end of instrumentation, the roots were randomly separated into 2 groups (n = 10). All specimens received final irrigation with 1 mL of 2.5% sodium hypochlorite. The solution remained in the root canals in Group 1 for one minute; and ultrasonic agitation was performed in Group 2 for one minute using a straight tip inserted at 1 mm from working length. The specimens were processed histologically and the sections were analyzed under optic microscope (×64) to quantify debris present in the root canal.

RESULTS

The samples submitted to ultrasonic agitation (Group 2) presented significant decrease in the amount of debris in comparison with those of Group 1 (p < 0.05).

CONCLUSIONS

The hybrid instrumentation technique associated with passive ultrasonic agitation promoted greater debris removal in the apical third of the root canals.