Purpose: The purpose of the present study was to assess the influence of repeated piezoelectric ultrasonic strokes on the marginal leakage of different ceramic cemented crowns.
Materials and Methods: Forty human maxillary first premolars received full coverage standardized preparation 1mm above the cemento-enamel junction (CEJ). All teeth were classified into 2 groups (n=20) related to the type of ceramic material examined; high translucent zirconia (HTZ) and hybrid resin ceramic (HRC). After all the fabricated crowns cemention with self-adhesive resin cement, each group was later partitioned into 4 subgroups (n=5). This wasbased on the amount of exposed ultrasonic scaler strokes. Microleakage assessment of buccolingual sectioned samples was performed, after their immersion in 2% methylene blue (MB) dye. Stereomicroscope was used for dye penetration measurement.
Results: The highest leakage percentage was recorded for HTZ, while the lowest mean value was achieved with HRC, the difference between the groups was statistically significant (P= 0.022 <.05) as reported by one-way ANOVA. 7 years of scaler strokes for HTZ showed the highest microleakage mean with statistical significant difference p=0.008 between the subgroups. All subgroups for HRC showed statistical insignificant difference with p=0.728.
Conclusions: Piezoelectric ultrasonic scaling has a minimal effect on microleakage behavior of the ceramic crowns within clinical accepted range. The material type significantly affected the marginal leakage.