THE EFFECT OF ULTRASONIC SCALING ON MICROLEAKAGE AROUND ZIRCONIA CROWN MARGINS LUTED WITH TWO RESIN CEMENTS

Aim: To evaluate the effect of ultrasonic scaling on microleakage around crown margins after being cemented with two resin cements.
Materials and Methods: Thirty two maxillary premolars were prepared to receive zirconia crowns. Specimens were divided into two groups (n=16): Group I, crowns cemented with self-etch adhesive resin cement ( Panavia F 2.0 ), Group II, crowns cemented with self-adhesive resin cement ( Panavia SA Cement Plus ). Each group was further subdivided into two subgroups according whether or not piezoelectric ultrasonic scaling was performed. All specimens were thermocycled then immersed in basic fuchsine dye before being sectioned buccolingually. Microleakage was then evaluated using the stereomicroscope. Microleakage percentage was determined and statistical comparisons were conducted using ANOVA followed by post hoc test.
Results: There was no statistically significant difference in microleakage percentage for zirconia crowns when being cemented with self-etch resin cement (Panavia F 2.0) with or without the application of ultrasonic scaling at the crown margins (P1=0.017). However, there was a significant difference in microleakage of specimens cemented with the self-adhesive resin cement (Panavia SA Cement Plus), where higher microleakage percentage was noticed after application of ultrasonic scaling than those without treatment ( P2<0.001).
Conclusion: Ultrasonic scaling could affect tooth/crown margin interface with subsequent microleakage. Self-etch adhesive resin cement showed higher resistance to ultrasonic scaling with resultant less microleakage compared to self-adhesive resin cement. Both types of resin cement could be used clinically, since the microleakage values of self-adhesive resin cement were within acceptable range compared to other studies.