Comparision of Marginal adaptation and surface topography of Gray MTA, white MTA,Gray portland cement and white portland cement (A Scanning electron Microscope Study)

Abstract

When nonsurgical root canal treatment fails to resolve periradicular lesions of endodontic origin or retreatment is contraindicated, surgical endodontic treatment may be needed. Periradicular surgery includes surgical debridement of pathological periradicular tissue, root-end resection, preparation of a root-end cavity, and placement of a root-end filling to seal the root canal. Aim: The purpose of this study was to evaluate and compare the marginal adaptation of gray and white mineral trioxide aggregate and gray and white portland cement as root-end filling materials as well as determine the surface topography in tested materials. Methods and Materials: Forty human single-rooted teeth were used in this study. Straight-line access cavities were obtained and the working lengths were established. The canals were cleaned and shaped by using the step-back method. The instrumented canals were dried and obturated with laterally condensed gutta-percha and AH26 sealer. Apical root resections were then performed by removing 3 mm of the apex at a 90degree angle to the long axis of the root, with a fissure bur in a high-speed handpiece with water coolant. Apical cavity preparations 3 mm in depth were made in each root with an ultrasonic device. Then the teeth were randomly divided into 4 experimental groups, each containing 10 teeth. Groups 1, 2, 3 and 4 were filled with gray Portland cement (Type II), white Portland cement, gray ProRoot MTA, white Pro-Root MTA, respectively. The crowns of the teeth were sectioned with a low speed diamond saw. The teeth were then stored in 100% humidity at 37C for 24 h to allow complete setting of the materials. Each of the root was sputter-coated with gold and assessed under SEM. The distance between the root-end filling materials and the dentin of the cavity walls was measured at four points. About the surface topography, surface texture, forms and dimensions of cristals was examined. Kruskal-Wallis test was used to determine statistical differences between groups. Results: Marginal adaptation: The average value of gap in grey Portland cement, white Portland cement, grey MTA and white MTA samples were 3.42+-0.93, 1.51+-0/58, 0.33+-0/25, 1.31+-0/43 ?m respectively. Surface topography: The average value of crystals dimensions in grey Portland cement, white Portland cement, grey MTA and white MTA samples were 5.15+-0.37, 3.56+-0.24, 5.27+-0.40 and 5.39+-0.44 ?m respectively. In most cases, polygon and triangular crystals were observed. But in white Portland cement group most samples had dense and completely fused structure with the lowest value of voids. the average value of crystals dimensions was ?m in this group. Conclusion: GMTA and GPC have the highest and lowest degree of marginal adaptation of root-end cavity walls, respectively. The marginal adaptation in WMTA was better than WPC. However, there was statistically significant difference just between GMTA and GPC groups ( p < 0.001). The averge value of crystals dimensions in WPC group are less than those of other groups.The size of crystals was similar in other three groups.