Impact of radiotherapy and shielding on the efficacy of the self-etch adhesive technique

Context: The exposure to gamma radiation affects the enamel and dentin in teeth restored with composite restoration, but a little has been done to protect from the detrimental effect. Aims: study was to evaluate the effect of gamma radiation, with or without shielding (0.5 mm thickness of lead), in Class V cavities prepared on teeth exposed before and after restoration using the self-etch adhesive technique. Methods: A total of 75 intact teeth were selected. The samples were divided into five groups: Group I (15 teeth) not exposed to gamma radiation. Group II and III exposed to gamma radiation as per the standardized radiation protocol (2 Gy/day for 5 days/week = 10 Gy/week for 6 weeks = 60 Gy). Group III shielded, using a "0.5 mm thickness of lead" molded into a "C" shaped tube. Standardized Class V cavities were prepared on the buccal surface of all teeth and were restored by composite. Groups IV (not shielded) and V (shielded) were then exposed to standardized radiation protocol. All the samples were evaluated for the assessment of microleakage under stereomicroscope. Statistical Analysis Used: Statistics were tabulated using the Kruskal-Wallis ANOVA test. Results: Samples showed a significant difference in dye penetration scores. Conclusions: The samples restored before being exposed to gamma radiations performed better. Shielding with 0.5 mm of lead has shown increased efficacy of self-etch adhesive system irrespective of the stage of exposure.