RESUMEN
PURPOSE: The aim of this study was to identify the effects of three aesthetic restorative materials on the wear between tooth and restoration by a pin-on-disk manner. MATERIALS AND METHODS: Six aesthetic restorative materials were used to prepare disk specimens for wear test, which were Lava Zirconia as zirconia group, Vintage MP and Cerabien ZR as veneering porcelain group, Gradia Direct microhybrid composite containing prepolymerized fillers, Filtek Z250 microhybrid composite containing zirconia glass and colloidal silica particles, and Filtek Z350 nanocomposite as composite resin group. Vertical loss of the worn cusp, change of the surface roughness of the restoration materials, and the surface topography were investigated after wear test under 9.8-N contact load. RESULTS: The porcelain groups (Vintage MP and Cerabien ZR) caused the largest vertical loss of teeth when compared with those of the composite resin and zirconia groups, and Filtek Z250 microhybrid composite results in the second-largest vertical loss of teeth. The surface of Filtek Z350 nanocomposite was deeply worn out, but visible wear on the surface of the zirconia and Gradia Direct microhybrid composite was not observed. When the zirconia surface was roughened by sand-blasting, vertical loss of teeth considerably increased when compared with that in the case of fine polished zirconia. CONCLUSION: It was identified that microhybrid composite resin containing a prepolymerized filler and zirconia with reduced surface roughness by polishing were the most desirable restorative materials among the tested materials to prevent the two-body wear between aesthetic restorative material and tooth.
RESUMEN
Glucosyltransferases GtfB, GtfC, and GtfD of Streptococcus mutans are virulent factors involved in dental caries. Consequently, they are considered to be target molecules in the development of vaccines against dental caries. Among them, GtfD plays a significant role in the sucrose-dependent cellular adhesion of S. mutans, and a number of studies have suggested that the N-terminus of GtfD is an important part of its role in enzymatic activity. In this study, we generated monoclonal antibodies against the N-terminus of GtfD (anti-GtfDN antibody) in an initial attempt to investigate its preventive efficacy against dental caries. To obtain anti-GtfDN monoclonal antibodies, the gene for the N-terminus of gtfD (2 kb) was cloned into an Escherichia coli expression vector, pQE30; then the expressed protein (about 75 kDa) was purified. The purified GtfDN protein was injected into BALB/c mice, and hybridoma clones were established. We obtained three hybridoma clones (HDN9, HDN11, and HDN28) capable of producing anti-GtfDN antibodies. Their binding specificity was characterized by ELISA, dot blot, and Western blot analysis after purification using affinity column chromatography. The isotype of the monoclonal antibodies was confirmed to be IgG2a.