Influence of fluoride characteristics on tooth surface protection in an erosive condition: a multifaceted characterization approach

Abstract Objective: To evaluate the effect of fluoride consistency and composition to protect enamel and dentin against the dental erosion. Materials and Methods: Bovine enamel and dentin specimens were treated with arti- ficial saliva, neutral fluoride gel (NFG), acidulated phosphate fluoride gel (AFG), neu- tral fluoride foam (NFF), and acidulated phosphate fluoride foam. The samples were subjected to cycling. Micro energy-dispersive X-ray fluorescence spectrometry, sur- face roughness (Ra), contact angle (CA), and scanning electron microscopy (SEM) were performed. Composition, CA and Ra data were analyzed by ANOVA and multi- ple comparison test (p < 0.05). Results: The dentin protected had a significantly higher mineral content than in the control. Eroded unprotected enamel had higher Ra values than normal surfaces. Fluo- ride treatments increased the Ra in dentin samples. AFG increased the CA in enamel. Fluoride foams increased CA in dentin with reduced mineral loss. SEM analysis found a deposited layer on enamel treated with AFG and remnants of deposits on dentin treated with NFG and NFF. Conclusion: Regardless of the form of application, fluoride provided protection against erosion, however with different levels. Clinical Significance: Applying the adequate fluoride form is relevant since the for- mulations have different effects on both enamel and dentin.