Aims:The purpose of this study was to evaluate the resistance to torsional failure and cyclic fatigue resistance of ProTaper Next (PTN), WaveOne, and Mtwo files in continuous and reciprocating motion.Settings and Design:Randomized control trial in a tertiary care setting.Subjects and Methods:A total of 10 new size 25.06 taper PTN X2, 25.06 taper Mtwo files, and 25.08 taper WaveOne primary files each was selected. A custom fabricated cyclic fatigue testing device with a 70° angle of curvature and 3 mm width; curvature starting at 6 mm from the tip was used. All instruments were rotated and reciprocated till fracture occurred and time till fracture of each instrument was recorded in seconds. For torsional failure testing 5 mm tip of each file was embedded in composite resin block and uniform torsional stresses (300 rpm, 2.0 Ncm) were applied repetitively by an endodontic motor with auto stop mode until file succumbed to torsional failure. Number of load applications leading to failure was recorded.Statistical Analysis Used:Data were analyzed using t-test for equality of means, Pearson correlation, and ANOVA test.Results:All the files showed superior resistance to cyclic fatigue in reciprocating motion when compared with continuous rotation mode. WaveOne primary files displayed maximum resistance to cyclic fatigue both in continuous and reciprocating motion. WaveOne primary files also demonstrated maximum resistance to torsional failure followed by PTN with Mtwo files exhibiting least resistance.Conclusions:Operating files in reciprocating motion enhances their cyclic fatigue resistance. WaveOne files showed maximum resistance to cyclic fatigue and torsional failure due to their cross-sectional diameter coupled M-Wire technology.

Aim: The aim of this study was to evaluate and compare the effect of 10% sodium ascorbate and propolis solution on the microtensile bond strength (MTBS) and resin tag penetration depth of composite after using 35% carbamide peroxide bleaching agent. Materials and Method: Sixty extracted human premolars were divided into five groups with 12 samples in each. Group I samples did not receive bleaching treatment and served as control. Group II samples were bonded with composite 2 weeks later, while those in Group III were bonded immediately after bleaching. The samples in Group IV and Group V were treated with antioxidants 10% SA and propolis solution at the rate of 1ml/min for 10 min, respectively, before composite bonding. The samples were then sectioned mesiodistally into two halves. One half was subjected to MTBS testing using a Universal Testing Machine. The other half was decalcified, sectioned, stained, and viewed under an optical light microscope to assess the resin tag penetration. The results obtained were statistically analyzed using a one-way analysis of variance followed by Post hoc test. Results: Group III showed significantly lower MTBS and resin tag penetration depth of composite compared to all other groups. Group V (propolis group) showed statistical significance with all groups except Group IV (SA group). Conclusion: Treatment with antioxidant propolis solution immediately following the bleaching will help to reverse the compromised bond strength which is comparable with sodium ascorbate.

Aim:The aim of this study was to evaluate the effect of different concentrations of sodium hypochlorite (NaOCl), solutions on the surfaces of nickel-titanium (Ni-Ti) rotary files using atomic force microscopy (AFM). Materials and methods:Sixteen unused ProTaper Ni-TI files of size F1, were selected for AFM evaluation at apical, middle and coronal segments. The selected files were then assigned into 4 groups • Group 1: Unused files (n = 4) • Group 2: 2.5% sodium hypochlorite irrigation (n = 4) • Group 3: 5.25% sodium hypochlorite irrigation (n = 4) • Group 4: 8.25% sodium hypochlorite irrigation (n = 4)The files were used as per the manufacturer's instruction, and the number of uses was restricted to five. Normal irrigation protocol was followed and the only variable being a concentration of sodium hypochlorite (2.5%, 5.25%, 8.25%). The post-treatment roughness average (RA) and root mean square (RMS) of apical, middle and coronal segments of the scanned profiles were then recorded using AFM and compared with the initial readings. The data was tabulated and analyzed using one-way analysis of variance (ANOVA). Conclusion:Within the limitations of the present study, it was concluded that different concentrations of sodium hypochlorite showed effect on the surface characteristics of Ni-Ti instruments.

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Background The restoration of endodontically treated tooth (ETT) with substantial loss of the tooth structure is challenging as it carries a higher chance of biomechanical failure than vital tooth in restorative dentistry. Post combined with complete coverage restoration is a well-established technique to save such teeth from fracture, but it does not follow the minimal invasive principles of adhesive dentistry. Case description This case report describes the management of endodontically treated mandibular premolar with lithium disilicate glass-ceramic endocrown (Emax). Conclusion Endocrown is a feasible option for the restoration of extensively damaged posterior tooth after endodontic treatment. Since posterior teeth are vulnerable to tooth loss, endocrown, which is a single partial restoration, can be regarded as replacing a single crown with intraradicular retention. How to cite this article Bejoy BM, Anitha S, George L. Conservative Bonded Restoration (An Alternative to Full Coverage Crown): A Case Report on Endocrown. Cons Dent Endod J 2020;5(2):42–47.