Protection against Dental Erosion and the Remineralization Capacity of Non-Fluoride Toothpaste, Fluoride Toothpaste and Fluoride Varnish

Abstract

Introduction: The oral cavity and the teeth are frequently subjected to numerous physiological pH variations, mainly due to the type of diet. These changes are the main cause of enamel demineralization and consequent breakage under mechanical forces. This causes severe sensitivity and sometimes pain, which endures unless the hard tissue is remineralized. Since enamel does not self-repair, the application of alloplastic materials that have the property of releasing remineralizing ions is strongly recommended. The aim of this in vitro study is to evaluate the effectiveness of two different toothpastes and a fluoride varnish in the prevention of demineralization, and their ability to remineralize enamel after it has undergone several acidifications. Methods: Eight human teeth with no caries or defects were prepared. The acid attack simulations were performed using a commercial cola carbonated drink. Samples were immersed in 5 mL of soft drink for two minutes at room temperature, and then were rinsed with distilled/deionized water. The immersion process lasted about 2 min, and was repeated four times for a total of eight minutes. Then, two different types of toothpaste, one with and one without fluoride, and a fluoride varnish were applied to the surfaces of the samples and rinsed off with demineralized water. A second acidification cycle was then carried out, with the subsequent reapplication of the three different products to evaluate their ability to protect against demineralization. SEM and profilometer analysis were then carried out to evaluate the results. Results: The statistical analysis showed a good remineralization capacity for all three products, especially in the fluoride-varnish-treated samples. However, regarding protection from demineralization, non-fluoride toothpaste was found to be ineffective, while fluoride toothpaste and varnish produced positive results. Conclusions: Dental professionals should advise fluoride toothpastes and varnishes over non-fluoride toothpastes. Fluoride toothpastes and varnishes represent a valid treatment for surface remineralization after a first acid attack and for protection from subsequent demineralization in an acid environment, such as that which can develop in the oral cavity.