![]() For every five preparations a new bur was used. Each cavity was prepared with a carbide bur (number 245). Sixty standardized Class II cavities were made on the mesial and distal surfaces of each tooth. ![]() After removing residual tissue tags, the specimens were cleaned with pumice. Thirty human permanent mandibular first molars with no crack, decay, fracture, abrasion, previous restorations, or structural deformities, which are periodontally compromised were collected and stored in normal saline. The aim of this study is to evaluate the microleakage in Bulk Fill composites using confocal microscopy. By activating the composite with sonic energy, it is possible to fill the cavity and adapt the low viscosity material easily, and then compact and model it while the composite changes its consistency until it reaches a higher viscosity.Īs per the manufacturer, the advantages are reduced working time and polymerization shrinkage, better adaptation to cavity walls, and ease of use. USA) combines the attributes of a low viscosity composite and a universal composite. The recent introduction of the SonicFill (Kerr corp. Improved depth of cure of at least 4 mm eliminates the need for layering. Elasticity and low polymerization shrinkage stress reduce microleakage, postoperative sensitivity, and secondary caries. On the other hand, some changes in restorative materials, made in the past, such as modified fillers and composite materials have improved performance of the resins.īulk Fill composites possess specific characteristics, including enhanced flowability to achieve consistent adaptation to the cavity preparation. The decrease of the polymerization shrinkage and consequent microleakage, can be obtained by an oblique layering technique with increments or cavity designs with a low C-factor. Microleakage is considered to be a major factor influencing the longevity of dental restorations. The restoration of the large Class II mesial-occlusal-distal restorations with Resin Bonded Composites materials is time consuming, in terms of placement, light-curing each increment, and the operator time required for separate etching, priming, and bonding techniques.ĭespite having good physical properties, the main shortcomings of composite resin materials are polymerization shrinkage and polymerization stress resulting in internal microcracks within the bulk of the material separation of the bonding agent from the cavity wall with resultant gap formation, marginal microleakage and the postoperative sensitivity enamel microcracks marginal staining wear discoloration lower fracture resistance recurrent caries and deformation of tooth. The technique involved in placing posterior composite presents many challenges. ![]() ![]() Composites were introduced in the 1960's and since then have undergone a lot of research and development refinement in these materials led to the development of microhybrid composite, with mean particle sizes in the 0.6–0.7 micrometers range. ![]()
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