The Effect of Soft Drinks on Enamel Sealed with Filled Orthodontic Primers: An In Vitro Study

Background: Decalcification of enamel is a major concern for orthodontists. The patient’s diet plays a major role in the demineralization process. In recent years, soft drink consumption in developing countries has increased dramatically. It is the orthodontist’s responsibility to minimalize white spot lesions during orthodontic treatment. Preventive measures include oral hygiene and fluoride treatments. Othodontist applied primer is another preventative measure that does not rely on patient compliance. Newer highly filled and flouride relesaing primers such as Opal Seal are now available. The effectiveness of these primers in preventing demineralization have not been extensively studied using newer evaluation methods. Methods: Bovine incisors were prepared and sectioned into blocks of enamel. Quantitiative Light-Induced Fluorescence (QLF) images were taken at baseline. Samples were randomly assigned into the control group (exposed enamel), Transbond XT group, or Opal Seal Group. Aging was simulated by subjecting the samples to 500 cycles in a thermocycling apparatus. Following thermocycling, the samples were pH cycled. During the acidic challenge, samples were exposed to a test beverage twice a day for 25 minutes. Test beverages included water, Diet Mountain Dew ,and Coke Classic. Samples underwent a total of 7 days of cycling. Final QLF images were taken to evaluate the demineralization of enamel. Results: A statistically significant interaction was found between the surface protected groups and the test beverage groups (p<0.05). A statistically signficant difference (p<0.05) was found between the Coke Classic group, Diet Mountain Dew (DMD), and Water treated groups. There was also a statistically significant difference between the Opal Seal, Transbond XT, and control groups (p<0.05). Conclusions: Coke Classic was the most aggressive in eroding through the sealant layer resulting in demineralization. The most protective effect was seen in the Opal Seal group with statistically significant prevention of demineraization versus control and Trasbond XT. Transbond XT showed statistically significant protection vesus control in the Coke Classic treated group only. These data suggests that enamel surface protection using a highly filled and flouride releasing and recharging primer may be a beneficial technique during orthodontic treatment to prevent enamel decalcification.