Light curing the primer - Beneficial when working in problem areas?

The purpose of this study was to investigate whether Transbond XT with MIP and Assure were affected by light curing the primers before contamination with blood or saliva. The study material consisted of 180 human premolars. The teeth were assigned into 12 groups of 15 specimens each. Metal brackets were bonded to each tooth under five different enamel surface conditions: dry, contaminated with blood or contaminated with saliva after primer application without light curing the primer, and contaminated with blood or contaminated with saliva after primer application with light curing the primer. The shear bond strengths of the two adhesive groups were not significantly different from each other within the same surface condition. There was no statistically significant difference between the groups bonded under dry conditions. On the other hand, curing the primer before adhesive application enhanced the bond strength in the contamination groups. Saliva and blood behaved similarly, showing higher bond strength values when the primer was light cured before contamination. However, they revealed bond strengths of different magnitudes because of the differences in the type and amount of inorganic and organic substances they contained. Under ideal conditions, light curing the primer did not introduce any advantages. However, curing the primer before contamination revealed higher bond strengths. To minimize the negative effect of contamination on bond strength, it would be appropriate for clinicians to light cure immediately after the application of the primer.