Case Report Indian Journal of Conservative and Endodontics, April-June,2017;2(2):69-72 69 Healing outcome of large peri-apical radicular cyst in maxillary canine region treated using mineral trioxide aggregate as an orthograde restorative material with 24 months of follow up - A case report Shaik Izaz 1,* , Bhargavi Dasari 2 , Nagesh Bolla 3 , Deepthi Vundavalli 4 , Sowmya Kallepalli 5 1,4 PG Student, 3 HOD, Sibar Institute of Dental Sciences, 5Dept. of Conservative Dentistry & Endodontics, MNR Dental College & Hospital, Andhra Pradesh, 2 Senior Lecturer, Dept. of Oral & Maxillofacial Radiology, KIMS Dental College, Andhra Pradesh *Corresponding Author: Email: shaik.ajas@gmail.com Abstract Mineral trioxide aggregate (MTA), is made up of hydrophilic fine particles that harden in the presence of dampness or blood. It constitutes the salts of tricalcium alluminate, tricalcium silicate and bismuth oxide, which makes it biocompatible and radiopaque when compared to classic materials for root filling such as amalgam, cements, Super-EBA, and IRM. Being an advantageous material it is beneficial to be used in most common peri-apical endodontic diseases. This case report centres the attention on the technical skills as well as on the healing ability of the most commonly used material. This article also discusses the amazing repair property of the material in the case. Keywords: Biocompatibility, Maxillary canine, Mineral trioxide aggregate, Two visit endodontics, Open apex. Introduction Bacterial infection of the pulp space and pulpal disease result in periapical lesions. These lesions are usually found during routine clinical check-up as sinus opening in the oral cavity or through radiographs. Peri- apical lesions are commonly classified as radicular cysts, dental granulomas or abscesses. (1) Among these lesions, the incidence rate of cyst ranges from 6% to 55%, the occurrence of granulomas varies from 9.3% to 87.1%, and for abscesses it spans from 28.7% to 70.07%. However clinical evident lesions which are larger in size, are most likely to be called as radicular cysts and the small size lesions are categorised under granulomas or abscesses. (2) For such larger or the small lesion, the preliminary procedures is to perform endodontic treatment, specially cleaning and shaping, to eliminate the cause such as necrotic tissue and infective bacteria. Cleaning and shaping and disinfecting the canals in the apical thirds are usually not adequately performed, for such elimination of cause cannot be expected; therefore, complete obturation of the prepared, cleaned and shaped canal space is necessary. Proper obturation leads to descend the chances of coronal leakage and bacterial recontamination and also seals the apex from peri- apical tissue fluids. (3) Based on the intrinsic properties and handling characteristics of obturation materials some of the very few are most commonly used for obturating the prepared coronal and radicular space. Parts of core materials have been classified as cements, pastes, plastics, or solid. These materials should exhibit certain characteristics to resolve and prevent endodontic failure. The ideal requirements of obturating materials are they should be bacteriostatic, seal apically and laterally, be non-irritating to peri-apical tissues, resist moisture, and provide radiopacity. Furthermore, the material should be sterile, non-shrinking, non-staining, easily placed and removed from the root canal system. Most widely used obturating material among many is gutta-percha. (4) However multiple studies suggested that gutta-percha is highly susceptible to microleakage when coronal restoration is not provided. A few number of in- vitro studies using dye penetration, fluid filtration, or bacterial leakage models stated that gutta percha as an obturating materials showed vulnerability. Bacterial challenges to exposed gutta-percha with sealer in various in vitro experimental models have shown leakage along the material within 3–30 days. (5) In the literature no known methods with wide variety of techniques of cold lateral or warm vertical compaction of gutta- percha can predictably produce a coronal bacterial-tight seal when the material is exposed to microorganisms. Although gutta-percha has an added advantage of handling properties and biocompatibility. However the susceptibility of gutta-percha to contamination and microleakage has led to the recommendation that sealed coronal core materials is placed directly after the completion of orthograde root canal treatment when using gutta-percha. (6) Mineral trioxide aggregate (MTA) might have a profound advantage when used as canal obturation material because of its superior physiochemical and bioactive properties. The original material (ProRoot MTA; Dentsply Tulsa Dental) was introduced to seal pathways of communication from the external surface of the tooth in perforation repair and as a root-end filling material in endodontic surgery. When early scientific observations and clinical outcomes demonstrated favourable biologic responses to the material, other uses for MTA were explored and investigated. MTA was found to be effective as a pulp