Microleakage in different tooth colored restoration systems (in vitro)
Mageed, Thafer R.
MetadataShow full item record
It is believed that microleakage, in tooth colored restorations, is the function of the restorative material type (composite, ceramic), and the curing technique (direct, direct-indirect, indirect). Based on that, a hypothesis was made that: 1. Microleakage would be minimal in ceramic restorations. 2. Microleakage would be less in composite restorations that were cured by either a direct-ndirect or an indirect curing technique than in composite restorations that were cured by direct curing technique. Eighty human extracted molars and premolars were divided evenly into eight groups. Modified MOD cavities were prepared in each tooth. In each cavity the gingival margin of one proximal box was placed beyond the C.E.J. Seven groups were made of composite restorations, and one group was made of ceramic inlays. Two composite restoration groups of the same type were cured differently to test the influence of the curing method on microleakage. The effect of dentin bonding on microleakage was evaluated by applying dentin bonding in one of two composite groups of the same type. These two groups were cured by direct curing method. The manufacturers' instructions were followed for each type of restoration. Then all restored teeth were stored in water, at room temperature, for six weeks. After that, all teeth were thermocycled for 125 thermocydes. Next, all teeth were kept into 0.2% crystal violet dye for 24 hours. Finally, all teeth were sectioned mesio-distally through the proximal boxes, and the dye penetration (microleakage) was scored. Microleakage was more profound at the dentin margins than at the enamel margins. While 82.5% of all samples exhibited microleakage at the dentin margin, 80% of all samples did not exhibit microleakage at the enamel margins. All groups exhibited some degree of microleakage at the dentin margins regardless of the restorative material type or the curing method even when dentin bonding was used. However, dentin bonding decreased microleakage significantly. The ceramic inlays group was the only group that did not exhibit microleakage at the enamel margins. There was no statistical significant difference, in microleakage, among most of the groups at the enamel margins. The only difference (at low significance) was found between the ceramic inlays versus two composite restoration groups. Those composite groups were cured by direct method and no dentin bonding was used in both of them. Ceramic inlays demonstrated a slightly better resistance to microleakage at the enamel margins than those two composite groups. There was no statistical significant difference in microleakage between the composite group that was cured by direct-indirect (heat-light) method and the composite group of the same type that was cured by direct method. According to this study, reduction of microleakage associated with tooth colored restoration could be attributed to the combined effect of dentin bonding, a material property, whether cavity margins are in enamel or in dentin and the curing method.
PLEASE NOTE: This work is protected by copyright. Downloading is restricted to the BU community: please click Download and log in with a valid BU account to access. If you are the author of this work and would like to make it publicly available, please contact email@example.com.Thesis (M.Sc.D.)--Boston University. Henry M. Goldman School of Graduate Dentistry, 1990 (Pediatric Dentistry)Bibliography: leaves 80-85.
RightsThis work is protected by copyright. Downloading is restricted to the BU community. If you are the author of this work and would like to make it publicly available, please contact firstname.lastname@example.org.