Objectives: Due to patients' growing aesthetic demand in today's diverse dental treatments, highly-aesthetic restorative materials, i.e. ceramics (porcelain, alumina and zirconia) and indirect composite resin materials are now extensively used. Meanwhile, designed to reduce technical errors and to provide simplified operation methods with no priming step involved, self-adhesive resin cements have also been increasingly introduced into the market. Under such circumstance, we have developed a new ion-releasing self-adhesive resin cement containing S-PRG filler and two types of adhesive monomers. This study aimed to evaluate the transparency of a cement layer suitable for bonding highly-aesthetic restorative materials on the basis of a contrast ratio.
Methods: Materials used for evaluation were a new experimental ion-releasing self-adhesive resin cement (SI: SI-R21003) containing S-PRG filler and two types of adhesive monomers, RelyX Unicem 2 (UN2, 3M ESPE), Maxcem Elite (MCE, Kerr), Breeze (BRE, Pentron), Speed CEM (SPC, Ivoclar), Smart Cem 2 (SC2, Dentsply) and SA Cement (SAC, Kuraray). Each material was filled in a mold (1.5mm-diameter, 1mm-thickness) and light-cured on both sides for 3 minutes using a light-curing unit (Solidilite, Shofu). The light-cured specimens were subjected to color measurement using a spectrophotometer (CM-3500d, Konica Minolta) to obtain their contrast ratio as an index of transparency.
Results: Whereas the average contrast ratio among the controls (UN2, MCE, BRE, SPC, SC2 and SAC) was 0.54, the contrast ratio for SI was as low as 0.28, suggesting its very high transparency.
Conclusion: In terms of aesthetic and preventive dental treatment, SI is expected to provide excellent clinical utility because SI 1)facilitates bonding of highly-aesthetic restorative materials through its simplified operation method involving no priming step, 2)exhibits extremely high transparency that emphasizes color tones of highly-aesthetic restorative materials, and 3)has fluoride-releasing capability provided by S-PRG filler.
Keywords: Adhesion, Cements, Esthetics, Fluoride and S-PRG Filler
See more of: Dental Materials 7: Polymer-based Materials-Physical Properties and Performance