The evaluation of four different restorative material used nonvital bleaching teeth respect to mikroleakage

SUMMARY Bleaching of non-vital teeth is a problem that requires esthetic and conservative treatment. Using conservative bleaching techniques in dentistry; tooth stains that cause esthetic problems are removed, also tooth and gum health are protected. Nowadays, several materials are used for restoration in dentistry. The materials used in the restoration of permanent teeth must be functional, esthetic, economic, resistant and let minimal micro- leakage. The aim of the in vitro study was to compare the microleakage of 4 different restoration materials used for the restoration of 60 artificially dyed anterior teeth containing no caries or restorations and were extracted for periodontal or orthodontic reasons. Endodontic cavity entrances were prepared onto the lingual surfaces of all teeth. Then, roots were removed 3 mm below the cementoenamel junction using a diamond bur. Each canal was enlarged by using gates glidden root canal burs. Each tooth was put into the test tubes 50 % filled with fresh human blood and centrifugated in order to be dyed artificially. The teeth were randomly divided into four grups, each containing 15 teeth and bleached by the same material using walking bleach technique. The composite resin restorative materials were applied onto the entrance cavities of teeth according to the instructions of manufacturers. Valux Plus was used for the first group, Tetric Ceram for the second group, Herculite XRV for the third group and Admira for the fourth group. Cross-sections were made for the measurement of microleakage, and taped on the micro-slide surface. Linear measurements were made from the dye penetration in cross- sectioned specimens using binocular stereo microscope at x25 magnification. The data obtained were evaluated statistically by using Kruskal-Wallis non-parametric test. Amongst the four different composite materials, Admira was found to be the composite with the least micro-leakage, followed by Herculite XRV, Tetric Ceram and Valux Plus. Keywords: Microleakage, non-vital bleaching, composite