No abstract

Aim:Overhang is the extension of restorative material beyond the cavity preparation. It changes sulcus microflora into organisms conducive to chronic periodontitis. After overhang removal the gingival index and microflora return to a healthy state. This can also improve access for dental plaque removal. The aim of this study was to compare the efficacy of three different instruments in association with amalgam overhang removal. Materials and methods:One hundred thirty-five intact premolars were selected. The teeth were restored with amalgam such that restorations had 1 mm overhangs. Overhangs were removed employing three different instruments in three groups: sickle scaler, ultrasonic scaler, and diamond flame bur. A stereomicroscope was utilized to evaluate both the level of smoothness in the restored area, tooth damage and probable gaps. The data were analyzed using post hoc and Chi-square. Results:The minimum and maximum time of removal were respectively obtained by ultrasonic scaler and sickle scaler, which was statistically significant (p <0.0001). Also, smoothness of the restored area in the sickle scaler group was significantly less than the other methods (p <0.0001).The percentage of tooth damage in the diamond flame bur group was significantly greater than the others (p <0.0001). The data concerning gap size showed no significant difference. Conclusion:Ultrasonic scaler causes no significant damage to the tooth during an overhang removal procedure. In addition, it offers an acceptable level of surface smoothness in restorations and decreases the required time for overhang removal.Clinical significance: Ultrasonic scaler can be recommended as an effective instrument for amalgam overhang removal.