Comparison between different finishing methods in Class II adhesive restorations

Objectives: the aim of this study was to evaluate the margins of class II cavities after four different finishing methods.

Methods: Thirty-six class II cavities were performed in sound teeth, randomly divided into four groups and finished with four different finishing methods: group A: 15 µm diamond coated bur (5414, Intensiv); group B: tungsten-carbide bur (H275.314.012); group C: diamond-coated tip with sonic instrument (Sonicflex2003L); group D: diamond-coated tip with ultrasonic instrument (Piezonmaster 600, Ems).

Cervical margins were observed using an optical microscope (x25). The morphological features of each sample were evaluated inside a 2,5mm section, placed over a grid with a period of 250 µm.

Results: The percentages of defects present on cavity margins were: marginal slashes (A:26.7%; B:17.8%; C:0%; D:0%); marginal cracks (A:6.7%; B:7.8%; C:5.6%; D:4.4%); plane imperfections (A:3.3%; B:8.9%; C: 0%; D: 0%); marginal creeps (A:0%; B:10%; C:2.2%; D:5%).

Margin sharpness has been assessed in the areas without defects providing a quality value rating from 1(worst) to 4(best). Mode and mean values were calculated for all groups: A) mode = 4, mean = 3.6; B) mode = 4, mean = 3.9 ; C) mode = 3, mean = 2.6; D) mode = 3, mean = 3.2 .

Conclusions: Rotary systems provided more regular margins than oscillating tips. Oscillating tips showed higher stability allowing easier handling and more accurate control.