Eroded Enamel and Clinical Outcome with Toothbrush and Dentifrice Use

Objective: This study was to characterize surface change of acid eroded enamel placed in dental appliances worn 24 hours a day for seven days. Methods: Optically flat bovine enamel with 3mm diam and 1mm thick cores were etched with 5% citric acid for 10 sec., scanned with stylus Mahr Federal profilometer and attached to the maxillary appliances worn by four participants in the first leg of 4X4 seven day cross-over study. Cores and appliances were brushed after breakfast and lunch and before retiring. Appliance were removed for 30 sec. brushing of the cores with either a water wet brush or the same ISO 11609 reference soft filament brush with MFP fluoride and dicalcium phosphate dihydrate abrasive system dentifrice (Colgate Palmolive® Cavity ProtectionTM). After brushing, all appliances were rinsed with water, appliances and natural teeth were cleaned with the same brush and dentifrice, rinsed with tap water and returned to the mouth. After 7 days, the enamel cores were removed and rescanned with the profilometer. For the second week, another set of 4 enamel cores were etched, characterized and mounted in the dental appliances. Brushing procedure for each participant was reversed. Results: Surface roughness (Ra as µm) and change as µm2 were essential identical after 7 days in the mouth due to the accumulation of soft surface debris. Enamel cores were then sonicated and rescanned to give Ra of 30.39 and 24.20 and wear of 24.37 and 56.42 for brushing with dentifrice and brush alone, which was statically significant. Conclusions: Neither brushing with ISO soft toothbrush alone or brushing with dicalcium phosphate dihydrate dentifrice altered significantly the eroded enamel surface, but tooth brushing with dentifrice significantly removed more soft enamel surface debris. Supported in part by Odontex, Inc.