IN VITRO STUDY OF DENTAL COMPOSITE ROUGHNESS AND MICROLEAKAGE OF REPAIRED OBTURATIONS BY VARIOUS TECHNIQUES

Abstract

ooth restoration is one of the most common procedures in dental practice. The replacement of the whole restoration leads to loss of tooth structure and it’s weakening, there is a risk of pulp injury, it’s time and cost consuming. According to the minimally invasive approach when minimal defects have occurred, or the diagnosed defect is localized only in one region of the restoration, the repairmant is a better choice than the total replacement of the restoration. The aim of the present study is to investigate the roughness of the surface of dental composites processed by different technics as well as to assess the micro-leakage between a cavity and composite walls and between old and new material after repairment. In our study, 28 extracted human teeth (premolars and molars without visible cavity) were used for micro-leakage assessement.Class5 cavities were preparated and obturated on them. For artificial aging, the teeth were thermocycled. They were placed in a colorant - 2% methylene blue solution, then washed, cut horizontally through the crown with diamond separators and re-examined on a microscope. The degree of penetration of the dye was evaluated by measuring the penetration depth using the TourView program. For roughness measurements20 samples (10 mm diameter and 4 mm thickness) were manufactured of micro-hybrid filling light curing material Essentia Universal (GC).The composite resin was put in a special plastic mold, then the surface was treated by different techniques and the surface roughness was measured by profile meter Mitotoyo SJ-210. Our study showed that the different types of surface treatments of dental composites lead to different roughness, with the highest values being obtained after laser treatment, followed by turbine application and air abrasion. Microleakage in repaired obturations is influenced not only by the roughness of the surface of the "old" material but also by the chemical composition and physical properties (viscosity) of the used primer and adhesive. The smallest microleakage was obtained in group A, where the "old" composite was treated with a turbine, etched and applied only G-Premio Bond.

Keywords

• dental composite
• repairment
• microleakage
• composite roughness