comparative evaluation effectiveness of er:yag lazer, manual and ultrasonic devises in srp of the root surfaces with sem method

abstract introduction: scaling and root planing is one of the most commonly used procedures during periodontal treatments. removal of calculus using conventional hand instruments is incomplete and rather time consuming. to find more efficient and less difficult instrumentation method, investigators have proposed lasers as an alternative or adjunct to hand instruments for scaling and root planing. the aim of the present study was to compare the effectiveness of three methods of hand instruments, ultrasonic and er:yag laser for scaling & root planing of root surfaces with sem method. methods and materials: this was an experimental study and samples included 15 extracted premolars collected from patients with periodontal problem. the teeth were sectioned in two parts vertically. therefore 30 samples were randomly divided in two groups. in the first group each surface of root from cej was divided in two parts. one part was scaled with manual curret and another by er:yag laser and third group was cleaned by ultrasonic methods. another surface was considered as control group. the surface changes were evaluated by sem in magnification of 50, 400 and 750 by 5 examiners. data was analyzed by spss program. results: the findings show that surface roughness is more in control group comparing with three other groups. besides roughness from the most to the least belong to: ultrasonic group, laser group & manual scaling group. kruscal-wallis test & mann-whitney test showed that there was a significant difference in the amount of surface roughness between manual group & laser group and also between control group & other groups and between manual and ultrasonic group. but there was no significant difference between rate of surface roughness in laser and ultrasounic group. conclusion: the efficacy of er:yag laser for scaling & root planing is not more than manual and ultrasonic instruments the amount of surface roughness created by er:yag is more than manual scaling but the difference is not significant comparing to ultrasonic scaling. key words: scaling & root planing, er:yag laser, surface roughness, ultrasonic scaling, manual scaling, sem.