CVD bur and smear layer deposition on primary dentin

Methods: Ten upper anterior primary, clinically sound teeth were selected and randomly divided into 2 groups. In G1 (5 teeth), buccal surfaces were grounded by using a conventional diamond bur #1090 (KG Sorensen, Brazil) mounted in a high-speed turbine, under water cooling (control group). In G2 (5 teeth), samples were grounded by using a CVD bur #UCP 1025 (Clorovale, Brazil) mounted in an ultrasound device (Profi II AS Ceramic, Dabi Atlante, Brazil), regulated to operate with 60% maximum power, under water cooling. All the samples were dehydrated, mounted on metal stubs and observed by scanning electron microscope (JSM 6100, Jeol). Analysis of electromicrographs was done by a single calibrated examinator for the absence, partial removal or total removal of SL, using scores (from 1 to 3), in three standardized sites/tooth (n=15/group).

Results: It was observed, in both groups, different levels of SL formation. Statistical analysis (Mann-Whitney Test, á= 5%) showed no difference between the two groups (p=0.75).

Conclusions: It was concluded that bur type (conventional diamond bur/high-speed turbine or CVD/ultrasound device) did not interfere in smear layer deposition on primary dentin surface.