The Effect of Some Carbonated Beverages on Enamel of Human Premolars (Scanning and Light Microscopic Study)

In modern societies, the increased consumption of soft drinks is becoming more important because of the concern for dental erosion. The aim of the present study is to reveal and compare the possible effect of some carbonated beverages on occlusal and cervical parts of enamel in the buccal surface of human premolars. Twenty sound (caries- free) human maxillary premolars extracted for orthodontic reasons were used in the present study. The teeth were then divided into: Control group: (before immersion in the beverages), in which the collected teeth were immersed at first in tap water and subdivided into 4 subgroups (5 teeth each) and named; Control Sprite, Control Mirinda Orange, Control Coca- Cola and subgroup R. Experimental group: (after immersion in the beverages) in which the first 3 subgroups which were used as control were then utilized as experimental after immersion in the corresponding beverage. They were named; Subgroup S (Sprite experimental Subgroup), Subgroup M (Mirinda Orange experimental Subgroup) and Subgroup C (Coca-Cola experimental Subgroup). The teeth were examined using SEM and light microscope. Morphometric study was performed, using computerized image analyzer for the assessment of affected band thickness. The SEM results of the experimental subgroups revealed that each beverage cause different pattern of erosion. In Subgroup S, the enamel surface was feather like and pitted. In Subgroup M, the enamel surface presented the honeycomb pattern. In Subgroup C, the enamel surface was nearly smooth with generalized structural loss. It was noticed also that the changes in enamel surface became more accentuated toward the cervical third. The light microscopic examination revealed that in both Subgroups S and C the outer enamel layer exhibited dark band of affection, while in Subgroup M this band was translucent. The affection of subsurface and deep enamel layers was noticed in all the experimental subgroups, in addition the changes in enamel became more accentuated toward the cervical third. The morphometric data revealed that the thickness of the affected band in the outer layer of enamel increased toward the cervical third in all experimental subgroups. This band was minimal in Subgroup S, and increased in Subgroup M, followed by Subgroup C. From the present study we can conclude that acidic beverages had deleterious effect on dental hard tissues. Among the investigated drinks of the present work, the Sprite had the least erosive potential, followed by Mirinda Orange, then Coca-Cola which had the most erosive potential. The erosive potential of a beverage was depended on its pH value, titratable acidity, type and concentration of the acid(s) present. Enamel affection for a given beverage was maximum at the cervical third and minimal in the occlusal