Influence of air abrasion and etching on enamel and adaptation of a dental sealant.

AIM Aim of this study was to evaluate the marginal microleakage of a dental sealant using different pre-treatment techniques of the enamel surface. METHODS Thirty extracted human intact teeth were selected and divided into 3 groups (n = 10) (1: acid etching with 37% orthophosphoric acid - 3M ESPE, St. Paul, Minnesota, USA; 2: air abrasion; 3: air abrasion + acid etching). The sealant (Helioseal, Vivadent Ivoclar AG, Liechtenstein) was applied into occlusal pits and fissures and light cured for 40 sec. All samples were thermocycled for 500 cycles (5 degrees -55 degrees C). Teeth were then immersed into a 2% methylene blue solution for 24 hrs and sectioned in a mesio-distal direction. Forty-eight sections were obtained for each group. Each section was analysed and photographed with a stereomicroscope (50x) assessing dye penetration (0: no dye penetration; 1: dye penetration restricted to the outer half of the sealant; 2: dye penetration restricted to the inner half of the sealant; 3: dye penetration into the underlying fissure). STATISTICS Data were statistically analysed (Mann-Whitney test). RESULTS Specimens prepared after air abrasion combined with acid etching showed lower microleakage expression if compared with the other two groups (p<0.01). Conclusion A combination of mechanical air abrasion and chemical acid etching represents an effective pre-treatment of enamel surface that may significantly reduce the risk of microleakage.