Healing after root-end microsurgery by using mineral trioxide aggregate and a new calcium silicate-based bioceramic material as root-end filling materials in dogs

Numerous materials have been used for root-end filling, such as amalgam, glass ionomer, composite resin, intermediate restorative material, Super EBA, and mineral trioxide aggregate (MTA). However, none of these materials are ideal. Currently, MTA is the material of choice, and its use is supported by the superior results in several published studies. In vitro studies have shown MTA to have both excellent biocompatibility and sealing ability, and these results have been corroborated in in vivo studies as well (1, 2). In several animal experiments that used MTA as a root-end filling material, cementum formation on the surfaces of MTA with no or minimal inflammation has been reported (3–8). Even though MTA is the root-end filling material of choice on the basis of biological principles, the cost and handling properties remain practical obstacles to its use (2). Recently, other calcium silicate cements such as EndoSequence Root Repair Material (RRM) (Brasseler USA, Savannah, GA) have been introduced to the endodontic field to overcome these limitations. RRM is dispensed in premixed, ready-to-use injectable or putty form. According to the manufacturer, the main compositions of both RRM formulations are the same (calcium silicates, zirconium oxide, tantalum pentoxide, calcium phosphate monobasic, and filler agents), differing only in particle size. In vitro studies have shown that the cytotoxicity and sealing ability are comparable to MTA (9–12); however, there are no in vivo or clinical studies to test its efficacy. Therefore, the purpose of the present comparative study was to evaluate healing after root-end surgery by using RRM putty and grey MTA (ProRoot MTA; Dentsply Tulsa Dental, Tulsa, OK) as root-end filling materials. Healing was assessed with different imaging modalities: periapical radiography, cone-beam computed tomography (CBCT), and micro computed tomography (CT). Tissue responses adjacent to RRM and grey MTA were also assessed.