Implant abutment screw reverse torque values before and after plasma cleaning.

This in vitro study analyzed the reverse torque (RevT) of abutment screws following different cleaning treatments. A convenience sample of 50 customized titanium abutment screw complexes was divided into five groups: cleaning by steam (control group), cleaning by Argon plasma (test groups 1 and 2 [with chlorhexidine gel]), and replacement of old screws with new ones (test groups 3 and 4 [with chlorhexidine gel]). Abutments were screwed onto implants and tested for RevT. The RevT of the test groups was significantly higher than that of the control group. No statistically significant difference between test groups was noted except between groups 2 and 3.