Antibiofilm activity of sodium hypochlorite against enterococcus faecalis using four irrigant activation protocols.

Aims: The aim of the study was to compare the activity of sodium hypochlorite (NaOCl) against Enterococcus faecalis when used with four different irrigation protocols. Methodology: Sixty-five single-rooted mandibular premolars with closed apex were prepared till size 35/0.04. The specimens were sterilized and infected with E. faecalis colonies that were cultured separately. The canals were randomly divided into four experimental groups based on irrigation activation protocol, with each group having 15 specimens each - Group 1: control, Group 2: manual dynamic agitation (MDA), Group 3: passive ultrasonic irrigation (PUI), Group 4: intracanal heating (ICH), and Group 5: passive ultrasonic irrigation followed by ICH (PUI ICH). The dentinal shavings were collected and sampled before (S1) and after (S2) the different irrigation techniques were performed. The colony-forming units were counted, and the bacterial reduction was calculated for each group. Results: A significant reduction in the number of E. faecalis colonies was observed for all the experimental groups (P < 0.001). The groups with ICH of NaOCl showed a considerable reduction in bacterial colonies than other groups (P < 0.001), with Group 5 that combined ultrasonics with ICH showed the highest reduction. Conclusion: ICH of NaOCl may be used as an adjunct to root canal irrigation to reduce the bacterial concentration from root canal spaces.

An in vitro radiological evaluation of irrigant penetration in the root canals using three different irrigation systems: Waterpik WP-100 device, passive irrigation, and manual dynamic irrigation systems.

Background: Instrumentation and irrigation of the root canal facilitating effective debridement is considered the most important single factor in the prevention and treatment of endodontic diseases. Aim: The aim of the study was to evaluate the depth of penetration of the irrigant depending on the final activation using Waterpik device modified with NaviTip needle, passive irrigation, and manual dynamic activation using the radiopaque solution in conjunction with digital dental radiography. Materials and Methods: Ninety freshly extracted single-rooted mandibular premolars based on the inclusion and exclusion criteria were used for this study. Access cavity preparation was done for all the samples, and the working length of each sample was determined using a size 10-k file. The radiopaque solution (Urografin) was delivered into (Groups A, B, and C) prepared canal of samples at the rate of 1 ml in 30 s with up-and-down motion. Results: The test results showed that Waterpik WP-100 group showed significantly high infiltration index values as compared to passive irrigation and manual irrigation group at P < 0.002 and P = 0.007, respectively. Conclusion: Sonic irrigation using a Waterpik device modified with a NaviTip needle permits better infiltration of the irrigant.

Apical microleakage in root canals with separated rotary instruments obturated with different endodontic sealers.

Aim: The aim of this study was to evaluate apical microleakage in root canals containing broken rotary instruments obturated with cold lateral condensation and thermoplasticized injectable gutta-percha, with different sealers, using glucose penetration leakage study. Materials and Methods: In this in vitro study, 96 extracted human mandibular premolars were decoronated, and the roots were randomly divided into eight groups (n = 12). Root canals were instrumented with #30 4% taper rotary files. The files were scratched 3 mm from the tip by a high-speed handpiece, and they were intentionally broken in the apical third of the canals. The middle and coronal sections of the canals were obturated by cold lateral condensation and thermoplasticized technique, using ZOE, resin, CaOH, and bioceramic sealers. Apical microleakage was measured using the glucose penetration method. Statistical Analysis: Independent Student's t-test and one-way ANOVA followed by Tukey's post hoc analysis were used for statistical analysis. Results: Bioceramic sealer group showed the least apical microleakage and this was then followed by the resin and CaOH groups demonstrating lesser apical microleakage and the highest microleakage was with the ZOE group. Mean apical microleakage scores between lateral and thermoplastic condensation techniques in each group were statistically significant (P < 0.001). Conclusion: Bioceramic sealer demonstrated the least apical leakage, whereas ZOE seal displayed the highest apical leakage.

Apical extrusion of debris following the use of single-file rotary/reciprocating systems, combined with syringe or ultrasonically-facilitated canal irrigation.

AIM: The aim of the study is to quantify the amount of debris extrusion after instrumentation with single-file rotary and reciprocating systems used either with conventional irrigation (CI) or passive ultrasonic irrigation (PUI) systems. METHODOLOGY: Sixty extracted human mandibular incisors were randomly assigned to two groups (n = 30); rotary single-file system, One Shape (OS-Group 1) and reciprocating single-file system, WaveOne (WO-Group 2) instruments. The two groups were further subdivided into two subgroups (n = 15); (A) PUI and (B) CI. The apically extruded debris was collected in preweighed glass vials as per the Myers and Montgomery method. After drying, the mean weight of debris was assessed with a microbalance and statistically analyzed using analysis of variance and Student's t-test. RESULTS: The reciprocating file system produced significantly more debris compared to the rotary file system using either of the irrigation systems (P = 0.04). CI produced significantly more (P = 0.02) debris extrusion compared to PUI irrespective of the file system used. CONCLUSION: Under the conditions of this study, both systems caused apical debris extrusion. Rotary single-file system produced less debris extrusion compared to reciprocating single-file system. Use of PUI may be advocated as an alternative to CI, as it causes lesser apical debris extrusion.

Influence of root canal curvature on the accuracy of an electronic apex locator: An in vitro study.

OBJECTIVE: This study investigated whether the canal curvature has an influence on the accuracy of Electronic Apex Locator. MATERIALS AND METHODS: Sixty mandibular posterior teeth were decoronated. A number (No.) 10 file was inserted into the mesiobuccal canal and radiographs were taken to determine the degree of curvature by Schneider's method. Samples were divided into three groups of mild (<20°), moderate (20-36°) and severe curvature (>36°). After enlarging the orifice, the actual canal length was determined by introducing a file until the tip emerged through the major foramen when observed under 20X magnification. The teeth were embedded in an alginate model and the Root ZX was used to determine the electronic length. The data was analyzed by Kruskal-Wallis test followed by Mann-Whitney test. RESULTS: The difference in measurement of Actual and Electronic working length was statistically significant between group 1 and 2 (P < 0.05) as well as between group 1 and group 3 (P < 0.05) with group 1 showing the lowest difference. CONCLUSION: Considering ± 0.5 mm as tolerance limit for accuracy, the device was 95% accurate for the mild curvature group and 80% accurate for moderate and severe groups.

Microleakage evaluation of Silorane-based composite and methacrylate-based composite in class II box preparations using two different layering techniques: an in vitro study.

AIM: The aim of this study was to compare the microleakage in Class II box preparations with the gingival margin above and below the cemento-enamel junction (CEJ) restored with Silorane composite and methacrylate composite using two different layering techniques. MATERIALS AND METHODS: Standardized box preparations (mesial box 1 mm above the CEJ and distal box 1 mm below the CEJ) were prepared in 60 upper premolars. The teeth were randomly divided into four groups containing 15 samples each; Group I: Restored with a Silorane composite using an oblique layering technique, Group II: Restored with Silorane composite using a vertical layering technique, Group III: Restored with methacrylate composite using the oblique layering technique, and Group IV: Restored with methacrylate composite using the vertical layering technique. The samples were stored in distilled water, followed by thermocycling and immersed in 2% methylene blue. The samples were sectioned and evaluated for microleakage at the gingival margin. STATISTICAL ANALYSIS: Kruskal-Wallis, Fischer exact test, Wilicoxon test, and Mann-Whitney U test. RESULTS: Silorane composite had significantly lesser microleakage. No significant difference in microleakage was observed above and below the CEJ for Silorane-based composite. CONCLUSION: Silorane composite resin showed lesser microleakage compared to methacrylate composite resin. CLINICAL SIGNIFICANCE: The Silorane-based composites improve the marginal adaptation due to their reduced shrinkage, thereby decreasing the residual stress at the adhesive-tooth interface.

The prevalence of bilateral three-rooted mandibular first molar in Indian population.

INTRODUCTION: The purpose of the present study was to evaluate the prevalence of bilateral three-rooted mandibular first and second molars in Indian population. MATERIALS AND METHODS: A total of 215 patients were screened bilaterally for mandibular first and second molar and 430 samples of periapical radiographs were obtained. The gender, symmetry, and prevalence of three-rooted mandibular first and second molars were recorded. The correlation between left and right side occurrences and distribution were recorded and analysed using Z-test. RESULTS: The results showed that 33 teeth had three-rooted mandibular first molars, 16 male and 17 female (P=0.442). Overall, 21 teeth of right jaw and 12 teeth of left jaw (P=0.103) showed presence of an extra-root. The prevalence of three-rooted mandibular first molars was 7.67% and second molar was 0.23%. The bilateral frequency distribution was 3.72% for the first molar. There was no statistically significant difference between right side and left side mandibular molars. Also, gender did not show a significant relationship with this variant. CONCLUSION: The endodontic treatments of first mandibular molars require a careful clinical approach in Indian population as a high racial prevalence of 7.67% three-rooted molars was found. However, in the same population, 0.23% mandibular second molars had three roots.

The influence of different composite placement techniques on microleakage in preparations with high C- factor: An in vitro study.

OBJECTIVE: This study evaluated the marginal leakage around class-I cavity preparations restored with Nanofilled composite (Filtek Z-350 A2 shade, 3M ESPE, USA) and a self-etch adhesive (Xeno III, DENTSPLY/Caulk) using different composite placement techniques. MATERIALS AND METHODS: Standardized class-I cavities were prepared on 36 caries-free, extracted human premolars and were randomly assigned to three groups: (1) Horizontal incremental curing was done; each increment of thickness 1.5 mm was cured one after the other using curing unit (T-LED, Elca Technology, Italy). (2) Concave surface was obtained with a ball burnisher on the first increment and cured for 20 seconds; subsequently, the next increment was placed and similarly cured. (3) Cavities were filled with resin, short of the occlusal surface; two cuts (mesiodistal and buccolingual) were made through the condensed resin and cured for 20 seconds, followed by addition of resin in the gaps created by the cuts and additional curing for 20 seconds. The specimens were stored in distilled water for three months and then subjected to thermocycling, followed by immersion in 0.5% methylene blue dye for 24 hours. The teeth were sectioned longitudinally and evaluated for microleakage under stereomicroscope, and the scores obtained were analysed with Fisher Exact test and Kruskal-Wallis nonparametric test. RESULTS: There was no statistically significant difference among three groups. CONCLUSION: None of the techniques was capable of eliminating the microleakage in preparations with a high C-factor.