root surface roughness after scaling and root planing with er:yag laser compared to hand and ultrasonic instruments by profilometry

objectives: scaling and root planing (srp) is one of the most commonly used procedures during periodontal treatment. the aim of this study was to evaluate the root surface roughness after srp with erbium: yttrium aluminum garnet (er:yag) laser compared to ultrasonic and hand instruments.   materials and methods: in this experimental study, 56 extracted sound single-rooted teeth with moderate level of calculus were selected and randomly divided into four groups: srp was performed with er:yag laser (100 mj pulse, 1w, 10hz, vsp and contact mode, with 50% water and air) in group one, hand instrument in group two and ultrasonic tool in group three. group four was considered as the control group. after srp, all samples were cut by servocut cutting machine into pieces with 3 × 3 × 2mm dimensions. the samples were mounted in acrylic resin. the surface roughness of the samples was evaluated with profilometry, and the data were analyzed using one-way anova and tukey’s test in spss software. results: surface roughness was higher in laser and lower in ultrasonic group compared to other groups. there was a significant difference in surface roughness between laser and ultrasonic groups (p=0.043), but there was no significant difference in surface roughness among other groups (p>0.05). conclusion: the results of this study showed that surface roughness after srp with er:yag laser was not higher than that after manual srp, but the former value was higher than that after srp with ultrasonic instrument.