Evaluation of root surface microtopography following the use of four instrumentation systems by confocal microscopy and scanning electron microscopy: an in vitro study

Abstract

The ideal instrument for initial periodontal therapy should enable the removal of all extraneous substances from the root surfaces without any iatrogenic effects. Because of that the objective of this study is to analyse and to compare the root surface roughness after using Gracey curettes, termination diamond burs (40 μm), a piezo-ceramic ultrasonic scaler and a piezosurgery ultrasonic scaler using confocal microscopy and scanning electron microscopy. A 2 mm × 2 mm interproximal root area of 20 teeth (n = 40 surfaces) was evaluated by confocal microscopy (×20 magnification) and scanning electron microscopy (×50 to ×1000 magnification). Teeth were randomly assigned to the following four groups: Gracey curettes with 15 vertical strokes; termination diamond burs (40 μm) at 3000 r.p.m.; a piezo-ceramic ultrasonic scaler with a power of 11; and a piezosurgery ultrasonic scaler in mode ROOT with a power of two. Confocal microscopy revealed that curettes [mean changes in the value of surface roughness average reduced by 0.11 ± 0.3], piezo-ceramic ultrasonic scaler (roughness average reduced by 0.47 ± 0.93) and piezosurgery ultrasonic scaler (roughness average reduced by 0.62 ± 0.93) left a smoother surface than termination diamond burs (roughness average increased by 0.39 ± 0.18). Statistically significant differences were observed in roughness (p = 0.005) between piezosurgery and termination diamond burs (p = 0.005). No statistically significant differences were between piezosurgery and Gracey curettes (p = 0.140) and between piezosurgery and piezo-ceramic ultrasonic scalers (p = 0.745). Confocal microscopy and scanning electron microscopy showed that piezosurgery seems to leave the smoothest surface. Surfaces treated with termination burs appear to show more scratches and pits. Three of the four instruments tested for root planing reduced surface roughness; however, the piezosurgery ultrasonic scaler produced the smoothest surface. The termination diamond burs (40 μm) produced a rougher surface than the ultrasonic instruments and the hand curettes. Further clinical studies are needed.