Purpose: This study assessed the comparative efficacy of three in-office treatment agents in patients presenting with dentin hypersensitivity (DH) at a university teaching hospital. Materials and Methods: A randomised, controlled study was conducted to compare the efficacy of Gluma desensitiser, Pro-Relief and Copal F in relieving the pain of DH. In 68 subjects with 508 hypersensitive teeth, the agents and placebo (distilled water) were applied to 127 hypersensitive teeth each. At baseline, the pain of DH to tactile and evaporative stimuli was measured using the visual analogue scale (VAS) and verbal rating scale (VRS). Post-application assessment was carried out at 10 min, 1 week, 2 and 4 weeks. Results: The mean difference in VAS between baseline and post-treatment periods significantly increased for all the desensitising agents (p 0.05) with both tactile and air-blast stimuli, except for the placebo. Gluma desensitiser had the highest mean difference at 10 min (3.7 ± 1.8) and 4 weeks (5.4 ± 2.3) for tactile and air-blast stimuli, respectively. However, using the VAS, no statistical significance was noted in the mean differences between the agents. With the application of Gluma desensitiser, a significantly higher number of teeth had no pain at 4 weeks using the VRS. Conclusion: Gluma desensitiser can be suggested as an appropriate desensitising agent for in-office treatment of DH. Keywords: Copal fluoride, dentin hypersensitivity, efficacy, Gluma desensitizer, Pro-Argin, Pro-Relief