Neutron Activation Analysis of Microleakage Around a Hydrophobic Composite Restorative

Neutron activation analysis with dysprosium as a tracer was employed to determine quantitatively the microleakage around the restorations of an experimental hydrophobic composite, as well as a commercial composite. Only a negligible uptake of tracer was obtained for the experimental composite, whereas a five-fold uptake was recorded for the commercial composite. Capillary penetration of fluid around a restoration could be greatly reduced by using a hydrophobic composite.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68248/2/10.1177_00220345800590090901.pd

Improved Method of Neutron Activation Analysis for Microleakage Studies

Improvements in the neutron activation technique for studying microleakage were achieved by selecting more suitable tracers and by using a more accurate method for evaluation of the activation data. Dysprosium was the most suitable tracer; it provided the least variation in the results and allowed the fastest activation and counting procedure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66594/2/10.1177_00220345740530022901.pd

A New Composite Restorative Based on a Hydrophobic Matrix

A hydrophobic restorative composite based on a fluorocarbon analog of an alkyl methacrylate and a bisphenol adduct was formulated into a one-paste system, which polymerized in the presence of blue light. Physical, mechanical, and water-related properties were determined. High contact angles and low water sorption were shown by the experimental composite. Capillary penetration of oral fluids around restorations, therefore, could be prevented in the presence of this highly hydrophobic surface. The physical and mechanical properties of the experimental composite were either comparable to or somewhat less favorable than commercial Bis-GMA composites.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67042/2/10.1177_00220345790580100401.pd

Sealant Effectiveness for Children Receiving a Combination of Preventive Methods in a Fluoridated Community: Two-Year Results

A series of preventive methods in combination have been used to reduce dental caries in children including dental health education, prophylaxes, pit and fissure sealants, topical application of fluoride and restorative care. Prophylaxes, sealant, and fluoride procedures are repeated every six months. Two-year results show reductions of occlusal caries increments of 74.3% for first graders and 77.1% for sixth graders. Sealant loss, as defined in this study, varied from 33% to 90% with the highest loss occurring in the newly erupted permanent molars during the first six months of the project. These high sealant loss rates are thought to be related to the age of the population which was designed to include children at the ages of peak eruption of permanent molar teeth (ages six and twelve). These teeth were often only minimally erupted and maintaining the dry field required for sealant retention was extremely difficult. However, in spite of these high rates of sealant loss, caries reduction on occlusal surfaces was highly significant in comparison to that of children who did not receive sealants.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68154/2/10.1177_00220345770560121801.pd

Better restorative, greater prevention.

Singapore dental journal14146-4