Aim: The aim of the present study is to compare the pulpal response to direct pulp capping with the mineral trioxide aggregate (MTA) and biodentine by light microscopic histological evaluation. Materials and methods: A total of 45 premolars scheduled for orthodontic extraction were selected and subjected to the direct pulp capping procedure. Class I cavities were prepared and MTA or biodentine was placed over the exposed pulp, followed by a composite restoration. After the experimental periods of 7, 30, and 90 days, the teeth were extracted and histological processing was carried out. The test materials were evaluated histologically for the degree of inflammation, dentin bridge formation, and thickness of dentin bridge at all the three different observation periods, tabulated and statistically analyzed using the Chi-square test. Results: At 7 days\' observation, all the samples in groups I and II showed a mild inflammatory response. At 1 month, a thin or partial dentin bridge was evident in all the samples in both groups. At 3 months, all the samples in both groups showed evidence of complete dentin bridge formation. There was no statistically significant difference between the MTA and biodentine groups. Conclusion: Biodentine was as effective as MTA in inducing a pulpal reaction with minimal inflammation and in dentin bridge formation.

Aim: To evaluate and compare the resistance to fracture of simulated human immature teeth treated with MTA/Biodentine as apical barrier, reinforced with a novel anatomic post. Materials and methods: Eighty extracted maxillary central incisors were used in this study. Access opening was done, and ProTaper rotary instruments up to F3 were used to prepare the root canal. Peeso reamers were used sequentially up to size 6 (1.7 mm) with 1 mm beyond the apex to simulate immature teeth. Irrigation with 2.5% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA) was done. They were then divided into two groups (n = 40 each) according to the apical barrier used for apexification: group I—apical barrier using Biodentine and group II—apical barrier using MTA. Each group was then divided into four subgroups: subgroup A (n = 10)—apical barrier using Biodentine/MTA with no obturation, subgroup B (n = 10)—apical barrier using Biodentine/MTA with everStick post as reinforcement, subgroup C (n = 10)—apical barrier using Biodentine/MTA with complete filling using the same material used for apical barrier, and subgroup D (n = 10)—apical barrier using Biodentine/MTA with prefabricated glass fiber post as reinforcement. All samples were incubated for two weeks at 37°C before subjecting to fracture testing using the Universal Testing Machine. A compressive load was applied at 135° to the long axis of the tooth. Results: Statistical analysis was done using one-way ANOVA test and post hoc Bonferroni test. In the above tests, p value less than 0.05 (p < 0.05) was taken to be statistically significant. Conclusion: A novel anatomic post, everStick post is a viable option for reinforcement of teeth with immature root apex and thin dentinal walls after apexification.

Introduction: The objective of this in vitro study was to quantify the amount of apically extruded debris using rotary and reciprocating nickel–titanium instrumentation systems. Materials and methods: Sixty mandibular central incisors were instrumented up to size 25 using WaveOne (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland), and ProTaper Next (Dentsply Maillefer, Switzerland). Bidistilled water was the irrigant used. Myers and Montgomery method with preweighed Eppendorf tubes was used to estimate the apically extruded debris. The mean weight of debris was assessed after drying with a microbalance and analyzed statistically using analysis of variance and the post hoc Student tukey HSD test. The significance level was p = 0.05. Result: The reciprocating file WaveOne produced significantly more debris compared with ProTaper Next (p < 0.05). No statistically significant difference was observed between WaveOne and ProTaper Universal, and between ProTaper Universal and ProTaper Next (p > 0.05). Conclusion: Under the limitations of this study, all systems caused apical debris extrusion. The extrusion of ProTaper Next was the least followed by ProTaper Universal with WaveOne showing the highest extrusion.

Aim: The aim of this in vitro study was to evaluate the efficacy of canal brush, Waterpik power flosser, and ultrasonic irrigation in removal of a sealer from the root canals using cone-beam computed tomography (CBCT). Materials and methods: Forty-five extracted mandibular premolars were prepared and obturated. The samples were divided into three groups (n = 15). In each group, the sealer was removed using canal brush, Waterpik power flosser, and ultrasonic irrigation. All the samples underwent CBCT imaging. The amount of sealer was evaluated in CBCT sagittal sections and was scored. The maximum concentration of residual sealer was recorded. Statistical analysis: Data were analyzed statistically using the IBM SPSS software version 20.0. Comparison of three groups with the amount of residual sealer was analyzed with the Kruskal–Wallis ANOVA and the Mann–Whitney U test and the level of significance is set at p < 0.05. Results: In comparison among canal brush (mean = 3.7), power flosser (mean = 2.7), and ultrasonic irrigation (mean = 2.3), with p value 0.0001, power flosser showed enhanced efficiency in removing the sealer in apical third when compared to ultrasonic irrigation. The removal of the sealer with power flosser and ultrasonic irrigation in coronal and middle third showed no significant difference. However, in the case of canal brush, there was significant difference in the sealer removal. The efficiency of canal brush is less when compared to power flosser and ultrasonic irrigation in all the thirds. Conclusion: The efficiency of sealer removal is more with both ultrasonic device and power flosser, but enhanced efficiency is seen with power flosser in apical third.

Aim: The aim of this clinical study was to determine the reliability of the electronic apex locator (EAL), in the presence and absence of a smartphone during working length determination. Materials and methods: Thirty patients requiring root canal treatment were included in this study. The working length was measured using DentaPortZX, a third-generation apex locator. Two smartphones were used in this study, an Apple iPhone 6s and a Samsung S7. For each canal, electronic working length was determined using a no 15 K-file under three different criteria: no smartphone was placed next to the EAL; an iPhone 6s with activated Wi-Fi, Bluetooth, and calling mode was placed next to the EAL; and Samsung S7 with activated Wi-Fi, Bluetooth, and calling mode was placed next to the EAL during the working length determination. Working length was determined thrice for each canal following all the three criteria and an average of the three values was considered as the final value for each criteria. Results: It was possible to determine the working length using an EAL under all three experimental conditions. The results of the nonparametric test, Kruskal-Wallis ANOVA, was found to be nonsignificant. No significant difference (p = 0.991) was found for electronic working length measurement in the presence or absence of smartphones used in this clinical study. Conclusion: The results of this clinical study conclude that smartphones can be used without the fear of electromagnetic radiation interference to the EAL during working length determination.

Aim: To evaluate the effect of 5.25% sodium hypochlorite (SH), 90% aloe vera (AV) gel, and 2% chlorhexidine (CHX) as disinfecting solutions on the physical and mechanical properties of gutta-percha (GP). Materials and methods: A total of 80 GP cones of size F3 ProTaper were obtained from sealed packet as four different groups. The experimental groups were disinfected with 5.25% SH, 90% AV gel, and 2% CHX except control group. The tensile strength of GP cones was measured under universal testing machine, and the surface texture was analyzed under stereomicroscope. Results: Mean tensile strength in the order of lowest to highest was 9.13 for 5.25% SH, 13.05 for 2% CHX, 13.56 for 90% AV, and 16.44 for control group. The 5.25% SH group showed pitting on surface and control group and AV group showed negligible pitting, whereas 2% CHX showed moderate pitting on surface under stereomicroscope. Conclusion: Aloe vera gel at 90% can be considered as a safer GP cone disinfectant. Clinical significance: The main objective of root canal treatment depends on the elimination of microorganism from the root canal system. To obtain aseptic condition, disinfection of GP cone is required, which may get contaminated during handling. Aloe vera gel can be a promising herbal disinfecting solution for GP cone without affecting any physical and mechanical properties of it.

Aim: To evaluate the amount of apical extrusion of bacteria from the root canal system following the use of different instrumentation techniques. Materials and methods: A total of 45 single-rooted mandibular premolar teeth were used. Access opening was done and root canals were then contaminated with a suspension of Enterococcus faecalis and then dried. The contaminated roots were divided into three experimental groups of 15 teeth each. GI: Hand instrumentation. The root canals were instrumented using the K-file in the step-back technique. GII: The root canals were instrumented using the Protaper Gold File system. GIII: The root canals were instrumented using the Mtwo File system. Bacteria extruded from the apical foramen during the instrumentation were collected in the vials. The resultant microbiological samples were removed from the vials and then incubated in culture media for 24 hours. The number of colony-forming units (CFU) was determined for each sample. The data obtained were analyzed using the Kruskal–Wallis one-way analysis of variance and Mann–Whitney U-tests, with α = 0.05 as the level for statistical significance. Results: There was a significant difference between the rotary instrumentation technique and the hand instrumentation technique (p < 0.05). The hand instrumentation technique was associated with the greatest apical extrusion of bacteria. Conclusion: All instrumentation techniques extruded intracanal bacteria apically. No significant difference was found in the number of CFU among the rotary instrumentation groups; the hand instrumentation technique extruded significantly more bacteria.

Statement of problem: Endodontically treated teeth are known to have reduced structural strength. Glass fiber posts may influence fracture resistance and should be evaluated. Purpose: The purpose of this study was to evaluate the influence of glass fiber post length on the fracture resistance of endodontically treated teeth. Materials and methods: Forty intact human maxillary canines were selected and divided into four groups, the control group consisting of teeth restored with a custom gold cast post and core, with a length of two thirds of the root. Other groups received prefabricated glass fiber posts in different lengths: group I/III, removal of one third of the sealing material (5 mm); group I/II, removal of one half of the sealing material (7.5 mm); and group II/III, removal of two thirds of the sealing material (10 mm). All the posts were cemented with resin cement, and the specimens with glass fiber posts received a composite resin core. All the specimens were restored with a metal crown and submitted to a compressive load until failure occurred. The results were evaluated by one-way analysis of variance (ANOVA) and the all pairwise multiple comparison procedures (Tukey honestly significantly difference test; α = 0.05). Results: The ANOVA showed significant differences among the groups (p < 0.002). The Tukey test showed that the control group presented significantly higher resistance to static load than the other groups (control group, 634.94 N; group I/III, 200.01 N; group I/II, 212.17 N; and group II/III, 236.08 N). Although teeth restored with a cast post and core supported a higher compressive load, all of them fractured in a catastrophic manner. For teeth restored with glass fiber posts, the failure occurred at the junction between the composite resin core and the root. Conclusion: The length of glass fiber posts did not influence fracture load, but cast post and cores that extended two thirds of the root length had significantly greater fracture resistance than glass fiber posts.