The CPP-ACP relieved enamel erosion from a carbonated soft beverage: An in vitro AFM and XRD study

Objectives: To investigate the CPP-ACP's effect on enamel against carbonated beverage erosion and explore the potential mechanism. Methods: A total of 30 enamel samples were prepared from sound bovine incisors, divided into 3 groups. Samples in the control group were kept in artificial saliva. Specimens' surfaces were smeared with a CPP-ACP agent (Tooth Mousse, TM) for 3 min, rinsed with distilled water for 10 s, merged into cola (Coca Cola, CC) for 4 intervals of 2 min, rinsed again for the TM + CC group. In the CC group, specimens were treated solely with cola for 4 intervals (2 min each). The cycles were applied at 0, 12, 24, 36,48 and 60 h. The surface microhardness (SMH) alterations were measured using a microhardness tester, the surface profiles were analyzed using the atomic force microscope, and the surface crystalline amount (I%) and crystallinity (FWHM) were analyzed using X-ray diffractometer. Results: The SMH were significantly decreased in CC group, showing the largest SMH alteration; the reduction of SMH in TM + CC group was lower than that in CC group, still larger than control. After cycles, the TM + CC group showed rougher surfaces than control, while the CC group had the roughest surfaces. The TM + CC had an I% higher than the CC, and lower than the control. The TM + CC group had a FWHM lower than CC, higher than control. Conclusions: CPP-ACP was able to relieve the erosion on enamel from carbonated beverage. (C) 2013 Elsevier Ltd. All rights reserved.