The gluma system for bonding to dentin: effect of acid pretreatment and surface wetness on bond strength

The aim of this study was to investigate the bond to dentin of a resin composite promoted by the Gluma bonding system applied to dry or wet dentin surfaces. The bonding system was modified as regards the conditioner and the composition of the primer. Various acidic conditioners were used, and the primer was modified by addition of water and acetone. Bond strengths between 12 and 22 MPa were recorded. It was concluded that bonds of good strength can be obtained with 20% phosphoric acid as pretreatment. It was further concluded that "moist" dentin does not interfere with bonding, but that "wet" dentin may reduce the bond strength about 25%

Fillings of resin composites and glass-ionomers: reduced marginal gaps

Marginal gaps associated with restorations of resin composite or glass-ionomer may have unfavorable consequences such as penetration of bacteria, marginal discoloration, risk of secondary caries, and damage to the pulp. The purpose of this in vitro study was to evaluate the effect of various pretreatments on the formation of marginal gaps at fillings of glass-ionomer and/or resin composite. The investigation was carried out using cavities prepared in dentin. The cavities were treated with 10% phosphoric acid and Gluma 3 before being lined with light-curing glass-ionomer cement and filled with resin composite. The control groups were resin composite alone and glass-ionomer alone, used with or without pretreatment of the cavities. After setting of the fillings, marginal gaps were measured in the microscope. It was found thar some combinations of pretreatment, glass-ionomer and resin composite gave rise to an excellent marginal seal