Evaluation of dental adhesive agent film thickness after light curing under a stream of nitrogen.

Document Type : Original Article


1 Conservative Dentistry Department, Faculty of Dentistry, Cairo University, Cairo, Egypt

2 Restorative Dentistry Department, Faculty of Dentistry, University of Alabama, Birmingham, USA


Purpose: The purpose of the study is to evaluate the efficiency of polymerizing unfilled resin based dental adhesives when cured under a continuous stream of nitrogen compared to air thinning and curing in ambient air environment.
Materials and Methods: 2 groups of 5 teeth were sectioned parallel the occlusal surface, to expose dentin. Unfilled universal adhesive (All-bond Universal, BISCO) was applied to the 2 groups; Control group, solvent was evaporated using air syringe and cured in ambient air, while for the intervention group nitrogen was used to evaporate the solvent and the adhesive was cured under a stream of nitrogen. After post curing and wiping the surface with alcohol, the teeth were sectioned parallel to the occlusal surface into slides of 1mm thickness to evaluate the film thickness of the cured adhesive under electron microscope (BS-SEM). Images of BS-SEM images were analyzed using (ImageJ2 software,)
Results: Statistically significant difference between the two groups was found in favor of the intervention group (P<0.05). The mean adhesive film thickness of the intervention group and the control group were 7.02μm and 3.33μm respectively.
Conclusions: Curing the dental adhesive under a stream of nitrogen from a nitrogen tank connected to a 3-way syringe, can be a clinically achievable alternative to efficiently cure resin. Further studies are required to test the bond strength and durability of the adhesive, when cured under a stream of nitrogen.