International Journal of Scientific and Research Publications, Volume 9, Issue 1, January 2019 106 ISSN 2250-3153 http://dx.doi.org/10.29322/IJSRP.9.01.2019.p8515 www.ijsrp.org A Comparative Evaluation of Fracture Resistance of Simulated Immature Teeth Using Different Obturating Material: An In-Vitro Study. Dr. Sunanda Gaddalay, Dr. Sonali Gite, Dr.Anita Kale, Dr.Yogesh Ahirrao, Dr.Sana Mohani, Dr. Amol Badgire Department Of Conservative Dentistry, MIDSR Dental College, Vishwanathpuram, Ambajogai Road,Latur DOI: 10.29322/IJSRP.9.01.2019.p8515 http://dx.doi.org/10.29322/IJSRP.9.01.2019.p8515 Abstract- Aim –To compare and also evaluate the fracture resistance of immature teeth using different obturating materials like MTA Angelus and Biodentine Materials and Method: Fifty freshly extracted single rooted human mandibular premolar teeth were used for the study which were decoronated at cementoenamel junction and divided into five groups (n = 10per group). Group 1: Samples served as negative control. Group 2 :MTA Angelus apical plug and then backfilling by gutta-percha. Group 3: Filling of root canal system entirely by MTA Angelus. Group 4 : Apical plug of biodentine and backfilling with gutta-percha. Group 5: Root canals completely filled with Biodentine. In four experimental group samples were shaped, cleaned and prepared using ProTaper rotary files. For simulation of immature roots, a #5 Peeso reamer was stepped out from the apex so that apices were enlarged to a diameter of 1.5mm. Group 2 and Group 4 samples were then filled with 5 mm of MTA angelus or Biodentine apical plug and backfilling with gutta-percha using AH Plus sealer. Group 3 and Group 5 rootcanal system samples were completely obturated with MTA Angelus and Biodentine, respectively. All the samples were loaded vertically until root samples fractured with the help of universal testing machine. Statistical Analysis: SPSS 23.0 version software was used for statistical analysis of forces at which fracture of the roots occurred and the results were analyzed with the one-way analysis of variance and post hoc tukey test. Results:In our study, root canal obturation which was done completely with MTA Angelus or Biodentine showed significantly higher fracture resistance (P<0.05) when compared to apexification done with MTA or Biodentine. Conclusion: Obturation of the root canals with bioactive materials showed highest fracture resistance when compared to apexification groups. Index Terms- Apexification, biodentine, mineral trioxide aggregate angelus, universal testing machine, vertical root fracture. I. INTRODUCTION hickess of dentin is one of the most vital aspects determining the resistance of teeth to fracture. The tissue loss of tooth reduces the fracture resistance toward occlusal or traumatic forces. 1 The most common site of dental impact injuries in the developing dentition is the maxillary anterior teeth. 2-4 These injuries many times lead to pulpal necrosis, which might cause the termination of root formation in developing teeth. 4-6 It has been stated that the immature teeth which have been endodontically treated have a relatively high incidence (>60%) of cervical root fracture, either spontaneously or even due to minor impacts. 7 The endodontic treatment of teeth with immature root formation has been a challenge due to wide, open apices and thin dentinal walls. 4,8 Various procedures and materials have been recommended to induce apexification in teeth with immature apexes. 9 Management of openapexes in immature teeth has been accomplished using long-term CH therapy, with success rates ranging from79% to 96%. 10,11 However, these teeth showed a50% reduction in strength vs the controls over 1 year 8 and were compromised by cervical root fractures 7,12 because of changes in the organic matrix of the dentin. Calcium hydroxide applied to the root canal system to promote the formation of an apical barrieris the conventional treatment in these clinical situations. 8,13,14 However, drawbacks of the long-term calcium hydroxide treatment requires multiple visits, patient adaptation problem, microleakage between the visits and an enhanced risk of root fractures. Hence, other alternatives to Ca (OH) 2 have been proposed,of which, the most promising are calcium silicate-based materials, such as mineral trioxide aggregate (MTA) and Biodentine. These root-end repair materials have been claimed to be biocompatible, capable of stimulating biomineralization, andalso offer a superior seal with better bond strength. 15 MTA has ingredients like tricalcium oxide and other mineral oxides such as tricalcium silicate, silicate oxide, and tricalcium oxide. 16 MTA is biocompatible, less cytotoxic, possess antimicrobial properties, offers low microleakage and can set in presence of blood and moisture. 17,18 Although MTA is a suitable material for clinical use, it shows some disadvantages such as a prolonged time for setting, difficulty in handling, and the probability of discoloration. 19 Biodentine is a silicate-based biologically active cement that has dentin-like mechanical properties and designed as a “dentin replacement” material. This is formulated using MTA- based cement machinery, also improving its physical and mechanical properties. 20 Establishment of a proper fracture resistance to the root dentin when obturated with various obturating materials, is an important key point for clinical success. Based on these T