Fluoride Uptake From Novel Device for Proximal Surface Fluoride Application

Objectives: This in vitro study compared the enamel fluoride uptake (EFU) from the traditional fluoride varnish application to a novel device (Cav-Aid) for fluoride application to the proximal tooth surfaces. Our null hypothesis was that there would not be a statistically significant difference in EFU from the two methods.
Methods: 30 bovine enamel blocks were randomly assigned to three groups (n=10): Cav-Aid, fluoride varnish, and sound untreated control. Enamel blocks were fitted into the proximal surfaces of human teeth and arranged in typodonts with blocks face-to-face creating two proximal surfaces simulating natural tooth contact. All samples were stored in artificial saliva for 24 hours before being subjected to their respective treatments. Cav-Aid was inserted between two opposing enamel blocks. Fluoride varnish was painted on the cleavage between adjacent teeth to diffuse into the interproximal surface. All typodonts were immersed in artificial saliva and stored in an incubator at 37°C for 24 hours. The control group was only used to determine baseline fluoride concentration in sound enamel. Following treatment, the enamel mineral content in the treated area was extracted from each block by acid-etching with 0.25mL of 1mol/L HClO₄ for 2 minutes, then vortexed for 10 seconds. Extract from each block was neutralized with 0.25mL of 1mol/L NaOH and the ionic strength was adjusted with 0.5mL of TISAB II. Then the fluoride ion concentration was measured using Ion-Selective Electrode and the data expressed as µgF/mm². Data was analyzed statistically (α=0.05) by Welch’s t-test.
Results: The Cav-Aid application showed significant (p<0.05) increase in EFU (128.9µgF/mm²) when compared to the traditional fluoride varnish application (68.70µgF/mm²).
Conclusions: This study demonstrated that Cav-Aid can effectively increase EFU. The significant difference in EFU by the Cav-Aid application compared to the fluoride varnish application suggests Cav-Aid is more efficacious in delivering fluoride to the interproximal surfaces.