ABSTRACT
The purpose of the present study is to evaluate the erosive potential of 4 fizzy drinks in Iran's Market by stereomicroscopy and SEM. Two I ranian made drinks [Cola zamzam and orange zamzam] and 2 imported ones [pepsi and Mirinda] were studied in this descriptive study as for their effects on tooth enamel [in vitro]. 120 intact premolar teeth, extracted for orthodontic reasons were divided in to 3 groups [A, B and C].Each group exposed to one of the drinks for one out of 3 exposure times as follows: A: 15 minutes, B: 45 minutes and C: 12 hours. Each one of the 3 groups was subsequently divided in to 4 subgroups [each containing 10 teeth], each of which were exposed to 20 ml of one out of the 4 drinks .The surface exposed to drinks were the same in all tooth samples [a 5 mm in diameter semi circular window]. Out of each of the 12 groups 2 teeth were selected randomly to be observed by SEM. Morphological changes of enamel exposed to drinks were as follows: enamel discoloration, loss of glossy appearance and etching appearance of enamel in stereomicroscopic views. Variable degrees of loss of enamel prisms were observed in SEM views, affecting prism heads and sheaths primarily and then tails in longer incubation time. Depth and extent of erosion increased parallel with the rise in incubation time. All the drinks demonstrated a relatively high erosive potential on human permanent enamel