Effect on the bond strength between composite resin and glass ionomer cement

Glass ionomer cements are tooth-coloured materials that bond chemically to dental hard tissues and release fluoride for a relatively long period. Glass ionomer is the ideal radiopaque liner for use under all types of composites. It bonds to dentin, reduces microleakage enhances the bond strength of composite

Effect of marginal leakage around class II composite resin restorations

The desire for improved esthetics have led to the appearance of "posterior composite resins" for occlusal restorations. Forty extracted permanent human molars and premolars of mesial or distal class II cavities were included. There was no leakage found at 58% and 89%. The lowest degree of leakage for all filling methods was found at the occlusal margin

Dentin-enamel bonding system to wet and dry dentin

[tokhalid321@yahoo.com] To evaluate the ability of dentin-enamel bonding system to bond to wet, as well as to dry, dentinal substrate. Dental Section, Bolan Medical College, Quetta. Sixty extracted human molars, free of obvious defects were selected for this study and divided equal in six groups. They were used within 2 weeks of harvest and stored in tap water at 4 degree C. For the experiment, the teeth were embedded in autopolymerizing acrylic resin in a stainless ring with an inside diameter of 1 inch. The matrices were removed from the teeth, and the teeth were stored for 24 hours in water at 37 degree C.-Group-1 had one cohesive dentinal failure. Group-3 exhibited cohesive dentinal failure nine times out of ten. Group-5 had four cohesive dentinal failures. All specimens in group-6 failed adhesively. Two-way analysis of variance showed that the mean shear bond strength of group 4 was significantly lower than those of groups-1 and 2. Mean bond strengths of groups-3, 5, and 6. Mean bond strengths of groups-3, 5, and 6 were not significantly different from one another. Mean bond strengths of groups 1 and 2 were not significantly different from one another, but both were significantly lower than those of groups-3, 5, and 6. Groups-3 and 5 also showed bond strengths with lower coefficients of variation than were found in groups in which the dentin was dried. The wet dentinal surfaces exhibited significantly higher bond strengths than the dry surfaces. It is suggested that the dentinal surface is adapted to much more thoroughly and intimately when the surface is wet