Aim: To compare the gingival trauma with the two polishing techniques viz., Prophy-Jet and rubber-cup polishing techniques using aluminium trihydroxide as polishing agent.

Methods: Thirty study subjects with gingivitis were studied. After scaling, Prophy-Jet and rubber- cup polishing techniques were applied on either side of the mouth using aluminium trihydroxide as polishing agent and the gingival trauma was assessed immediately after, 7 days and 21 days posttreatment using trauma index.

Results: Mean Trauma index scores immediately after the rubber-cup polishing technique was 0.27±0.14 and after Prophy-Jet polishing technique was 0.50 ±0.15. A reduction in the mean Trauma index scores was seen at 7 and 21 days after treatment after both the techniques with the mean Trauma index score of 0.02±0.01 with rubber-cup and 0.03±0.02 with Prophy-Jet technique at 21st day of evaluation.

Conclusion: No significant difference in gingival trauma between by Prophy-Jet and rubber-cup polishing techniques using aluminium trihydroxide at 7 and 21 days post-treatment was observed despite of higher gingival trauma immediately after air polishing using aluminum trihydroxide.