Marginal Fit Effect of Burs with Different Grain Thicknesses in Glass Ceramic Restorations

Project no. 23921 · Status: Kapanmış (Yayın bekleniyor) · 2022

Summary

In our study, the extent of edge compatibility of restorations produced on teeth prepared with burs with different green zones will be investigated. The research should be carried out with 50 registered human molar teeth with intact enamel preserved in formalin solution (1/10 37% formalin) and monitored for the last 3 months in the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Ege University. 5 different groups will be created (n=10). Preparation will be completed with a chamfered ring cutting bur for the first group only black belt (181 µm), the 2nd group only green belt (151 µm), and the 3rd group only neutral belt (107 µm). In the 4th group of teeth, preparations will begin with black belts (181 µm) and cutting will be completed with red belts (46 µm). In Group 5 teeth, preparations will begin with green belts (151 µm) and cutting will be completed with red belts (46 µm). Equal amounts of material will be removed from the vestibule, palatal and approximate percentages for each tooth, maintaining a 6 - 8 degree angle on the axial walls, with a margin width of 1 mm for each group. A 1.5 mm cut will be made from the occlusal side. In order to ensure standardization, an index is prepared and cutting depth control results are obtained from silicone.  During the preparation process, the preparation time for each group will be measured with a stopwatch. Digital measurements are obtained from all teeth prepared in a standard manner with an intraoral digital scanning device (Cerec Omnicam, Dentsply Sirona, Bensheim). Crowns with similar features for each tooth will be designed and produced in the dental software (Cerec Software). The designed repairs will be produced from liter dislicate-containing glass ceramic material (IPS e max CAD, Ivoclar Vivadent) in a computer-aided manufacturing unit (Cerec MCXL, Dentsply Sirona).  After the crowns are placed on the prepared teeth, the margin area will be evaluated in terms of measurement gap with a stereo microscope over a total of 32 points on 4 sides. In addition, images obtained by scanning electron microscopy at 8 points in the buccal environment of 2 samples of the group. The data obtained is analyzed and transferred statistically.   For this cutting section, it is aimed to examine the effect of bur operation in different green sizes on the marginal adaptation of the enamel and to monitor the effect on the estimated time that can be spent at the bedside during preparation.

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