RESUMEN
The objective of this study was to evaluate the use of naphazoline hydrochloride in comparison with aluminum chloride for vertical gingival displacement. The inclusion criteria were: patients with a good general systemic condition; periodontal health; and thick gingival biotype. Moreover, the exclusion criteria were: smoking individuals; canine teeth or central incisors with carious lesions, abrasion, erosion, prosthetic abutments or unsatisfactory restorations; patients with periodontal disease; and users of continuous medication. 72 teeth were included and the Square Block Design was used to randomize the samples. Three measures were obtained from each tooth, and mean vertical gingival displacement was calculated. A descriptive analysis of the average displacement was performed. The normality test used was the Lilliefors' Test and for comparison between treatments, the Kruskal-Wallis Test was used. The Bartlett's Test for homogeneity of variances was used and a 5% (p ⟨ 0.05) significant level was considered. Thus, the Aluminum Chloride and Naphazoline Hydrochloride showed no statistically amount of gingival retraction than the control group (p = 0.3822). The average of gingival vertical displacement in all groups were less than 0,5 mm. The technique used did not allow any amount of horizontal displacement on obtained models.