Remineralization Potential: CPP-ACP Versus Nano-hydroxyapatite or Sodium-fluoride on Erosive Enamel

Objectives:
Evaluate surface morphology of erosive enamel lesions remineralized using sodium fluoride, Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and Nano Hydroxyapatite (Nano-HAP) using atomic force microscopy.
Methods:
Specimens were prepared from 15 Labial segments cut from human incisors. Then placed in Teflon molds measuring (10 × 8 × 2mm) and embedded in flowable resin composite. The baseline roughness was measured for all the specimens before starting experimentation.
The labial surface was grounded using silicon carbide papers with consecutive grades of 600, 1000 and 1200 for producing flat surfaces.
Specimens were divided into five groups according to remineralizing materials used. Gp1; Control (no de or remineralization), Gp2; enamel only demineralized, Gp3; 5% sodium fluoride, Gp 4; CPP-ACP, and Gp5; Nano-HAP 10%. Specimens of groups 2, 3, 4 and 5 were subjected to a demineralization cycle by immersing in 6 ml of soft drink for 2 min at four consecutive intervals at 0, 8, 24 and 36 h for a total of 8 minutes. In between, specimen were stored in deionized water.
The baseline roughness, was measured before starting experimentation and after 24 hours from the last procedure of demineralization and remineralization cycles using atomic force microscopy
Results: NaF group showed the greatest roughness (153.80+ 27.93) followed by demineralization group (102.28+31.69), control group came next (66.29+22.12) followed by CPP-ACP group (62.95+18.48), whereas the lowest roughness was recorded in Nano-HAP group (57.11+18.81).
For the demineralization, NaF and CPP-ACP groups, a significant increase in the roughness was evident after demineralization and remineraliztion procedures.
Conclusions:
Application of Nano-HAP and CPP-ACP paste may decrease the tendency to dental erosion produced by a soft drink.
Nano-HAP has greater remineralization capacity than CPPACP paste and NaF.