Comparative Evaluation of Pushout Bond Strength and Apical Sealing Ability of Three Different Root Canal Sealers: An Invitro study

INTRODUCTION : The ultimate goal of root canal therapy is total obturation of the root canal system. The physical properties necessary for this function included adaptation and adhesion of the filling material to the root canal wall, because gutta-percha does not directly bond to the dentine surface. Ideally, the sealer should be capable of producing a bond between core material and dentine wall. AIM : To evaluate and compare the push out bond strength and apical sealing ability of AH plus, Zinc Oxide Eugenol and MTA plus root canal sealers after obturation using single cone technique. METHODOLOGY : Total of 120 mandibular premolar teeth were used and decoronated. All teeth were prepared using protaper rotary file system upto F3 file size using Xmart plus (DENTSPLY Maillefer) and obturated with guttapercha size of final instrumentation using single cone obturation technique. The irrigation solution used after each instrumentation were 2.5% NaOCl, 17% EDTA and normal saline. Samples were grouped into three based on the root canal sealer used of each group containing 40 number of teeth. In Group I, specimens, obturation done using Gutta-percha and zinc oxide Eugenol sealer; Group II - Gutta-percha and AH Plus sealer and Group III- Gutta-percha and MTA Plus sealer. Half of the specimens in each group were used for push out bond strength analysis. Horizontal sections of 2 mm thickness were made from coronal, middle and apical region of samples and underwent push out bond strength test with the help of universal testing machine at a cross head speed of 0.5 mm/ min. Specimens were analysed using stereo microscope for the mode of failure and extent of fracture using scanning electron microscope. Remaining half of the specimens were coated with modelling wax except apical foramen and immersed in methylene blue for 2 days. Stereo microscopic photographs of each samples were taken and linear measurement was calculated using CMEIAS software. RESULTS : AH plus sealer group showed the highest push out bond strength than Zinc oxide Eugenol and MTA plus root canal sealer. Apical segment of each test group demonstrated the highest mean bond strengths than the coronal and middle segments.Apical microleakage value in AH plus sealer group was less on comparing Zinc Oxide Eugenol and MTA plus root canal sealer. CONCLUSION : AH plus sealer showed higher push out bond strength than Zinc oxide Eugenol and MTA plus root canal sealer. Apical segment of each test group demonstrated the highest mean bond strengths than the coronal and middle segments Apical microleakage value in AH plus was less on comparing zinc oxide Eugenol and MTA plus root canal sealer