Evaluation of the effect of self-assembling peptide and fluoride varnish, alone or in combination with laser irradiation, on artificial enamel caries: a SEM/EDS and Micro-CT study

Objective The aim of this study was to investigate the effect of remineralization agents such as fluoride varnish and P-11-4, alone and in combination with Er: YAG laser, on in-vitro hard tissue repair in artificial enamel lesions. Materials and methods A total of sixty enamel surfaces of 4 x 5 mm in size were created on both the buccal and lingual sides of thirty extracted wisdom teeth. Remineralization agents were applied to the specimens that were grouped as follows: Group 1, control; Group 2, fluoride varnish (FV); Group 3, P-11-4; Group 4, laser; Group 5, laser + FV; and Group 6, laser + P-11-4. The fluorescence level was determined with DiagnoDent. The enamel mineral density, area and volume, and caries lesion area and volume were determined with micro-computed tomography (mu CT), surface features were evaluated using scanning electron microscopy (SEM), and elemental analysis was performed using energy dispersive x-ray spectroscopy (EDS) . Results For specimens treated only with self-assembling peptide P-11-4, the caries lesion area (mm(2)) values were 38.19 and 21.62, and the caries lesion volume (mm(3)) values were 6.27 and 2.99, respectively for pre- and post-treatment. In combination usage of self-assembling peptide P-11-4 and laser, the caries lesion area (mm(2)) values were 38.39 and 16.91, and the caries lesion volume (mm(3)) values were 11.15 and 3.64, respectively for pre- and post-treatment. In the application of the P-11-4 alone and in combination with laser, there was a statistically significant decrease in DiagnoDent values, an increase in enamel volume(mm(3)),enamel area(mm(2)) and mineral density(g/cm(3)) values and a decrease in caries lesion volume(mm(3)) and area(mm(2)) obtained by mu CT, and an increase in %Ca and %F values obtained by SEM/EDS analysis (p < 0.05). It was discovered that the samples treated with P-11-4 had a considerably higher rise in the Ca/P ratio than the samples treated with FV (p < 0.05). The calcium content increased significantly more when P-11-4 application was combined with laser irradiation (p < 0.05). Conclusions The combined use of self-assembling peptide P-11-4 and laser accelerated the remineralization process and increased the remineralization capacity.