6 implants were divided into 6 different groups and instrumented by each plaque control devices as follows. 1) Group I : untreated control 2) Group II : Titanium curette(Titanium curette®, 3i) 80 vertical/horizontal strokes 3) Group III : Plastic curette(Implacare®, Hu-Friedy) 80 vertical/horizontal strokes 4) Group IV : Plastic tip-ultrasonic scaler(Amdent®, Amdent) 160 seconds 5) Group V : Rotating interdental brush(Identobrush®, Identoflex) 160 seconds 6) Group VI : Abrasive rubber cup polisher(Zircate®, Prophy paste, Dentsply) 160 seconds.

All specimens were prepared for evaluation by surface roughness tester, optical stereomicroscopy(OM) and scanning electron microscopy(SEM).

The Ra and Rt mean values of the tested specimens were

1) Group I (Ra=0.170±0.007µm, Rt=1.297±0.016µm)

2) Group II (Ra=0.209±0.006µm, Rt=1.602±0.110µm)

3) Group III (Ra=0.179±0.001µm, Rt=1.429±0.055µm)

4) Group IV (Ra=0.182±0.005µm, Rt=1.511±0.085µm)

5) Group V (Ra=0.301±0.008µm, Rt=1.882±0.131µm)

6) Group VI (Ra=0.147±0.010µm, Rt=1.059±0.021µm)

In Ra values, experimental group II, V, VI were statistically significant different when compared with control.

OM and SEM observation showed that experimental group III, IV were minimal changes when compared with control and group VI was smoothest among other experimental groups.

The results suggested that plastic curette and plastic tip-ultrasonic scaler were predictable devices to titanium implant surface.