Photometry and image analysis software ‘ImageJ’ to compare three methods of gingival depigmentation

Purpose: Gingival depigmentation, a procedure for establishing pink-white aesthetics, can be performed using different techniques. Objective assessment of the efficacy of one technique over another can aid in determining the most efficient method. This study was done to objectively compare the efficacy of three different methods of depigmentation: cryosurgery, electrosurgery and LASER, using photometry and the image tracing and analysing software, ImageJ. Methods: Thirty subjects between 20 and 60 years who reported to the Department of Periodontology of a dental teaching hospital with the complaint of pigmented gingiva were divided into three groups randomly for depigmentation using cryosurgery, electrosurgery or LASER. The distribution of pigmentation was assessed using the gingival pigmentation index (GPI) and the intensity of pigmentation was analysed using the software, ImageJ. The parameters were assessed at baseline, in the immediate post-operative phase and at 1-, 3- and 6-month post-depigmentation. The data obtained was analysed using ANOVA with post hoc Bonferroni test. Results: There was a reduction in distribution and intensity of pigmentation in all groups in the initial period following depigmentation. Beyond 3 months, the distribution of pigmentation increased for the cryosurgery group, followed by electrosurgery and LASER groups. Using the ImageJ to assess the intensity of pigmentation, it was found that at 6 months, pigmentation density was greater in the electrosurgery group, followed by LASER and cryosurgery groups. Conclusion: Results obtained indicate that although cryosurgery has the greatest effect on the intensity of pigmentation, LASER is the modality of choice from the perspective of patient acceptability and distribution of pigmentation.