Effect of application time of acidulated phosphate fluoride on demineralization of deciduous and permanent enamel

Author(s)

Ana Flávia Bissoto Calvo

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2011-04-04

Examining board members

Cinthia Pereira Machado Tabchoury; Josimeri Hebling Costa; Rita Villena Sarmiento

• Advisor: Jaime Aparecido Cury; Cinthia Pereira Machado Tabchoury

Abstract

Although the effect of acidulated phosphate fluoride gel (APF-gel) on caries reduction in permanent teeth is based on evidence, previous in situ study, conducted under low cariogenic challenge suggests that the professional application of APF-gel for 4 minutes does not promote greater resistance to demineralization for permanent enamel than 1 minute, however under higher cariogenic challenge the result could be different. Moreover, although deciduous teeth are more susceptible to caries than permanent ones, there are no studies in the literature that compare the application time of APF in deciduous enamel. Thus, an in situ study was conducted with the aim of evaluating the effect of application time for 1 and 4 minutes of professional APF gel with 1.23% F on demineralization of deciduous and permanent enamel, as well as on F formed and retained on enamel and F concentration of dental biofilm formed, in a condition of dental biofilm accumulation and high frequency of sucrose exposure. In three experimental phases, 16 adult volunteers wore palatal appliances, containing 4 deciduous enamel slabs in one side and 4 permanent ones in the other side. At the beginning of the first phase, the volunteers were randomly assigned by the treatment they would start the study: Negative control: no treatment; APF-1 min: APF application for 1 min, performed on the first day of each experimental phase; APF-4 min: APF application for 4 min, and at the end of the experimental phases all volunteers had been submitted to all treatments. Additionally, a deciduous and a permanent slab were fixed with wax in anterior position on appliance for determination of fluorine (F) as calcium fluoride ("CaF2") formed on enamel and, after 30 minutes, a plastic mesh was fixed in the acrylic appliance over the other dental slabs. During the experimental phases, 20% sucrose solution was dripped extraorally over the slabs 8 x/day and the volunteers used non-fluoridated dentifrice. After 14 days of the beginning of each phase, dental biofilm formed was collected and analyzed with regard to F concentration in the fluid and the solids. On the slabs was determined "CaF2" retained on enamel and mineral loss was evaluated by enamel cross- sectional hardness. APF-gel application reduced demineralization in both dental substrates (p<0.05), independent of the application time (p>0.05). The concentration of "CaF2" formed and retained was significantly higher in the groups treated with APF-gel (p<0.05), however without difference between the application periods (p>0.05) either for deciduous or permanent enamel. The results of the present study suggest that, even under a high cariogenic challenge, a shorter time of professional application of APF-gel, that is, 1 min, presented the same anticaries effect as the time of 4 minutes, either in deciduous or permanent enamel (AU)

• FAPESP's process: 09/01785-6 - Effect of application time of acidulated phosphate fluoride on demineralization of enamel in a high cariogenic challenge in situ
• Grantee: Ana Flávia Bissoto Calvo
• Support Opportunities: Scholarships in Brazil - Master