Figure 2. Effect of P₁₁-4 on remineralization and demineralization behavior of caries-like lesions in human enamel under simulated intra-oral conditions. (a) Effect of treatment with P₁₁-4 on mineral loss/gain by caries-like lesions of human enamel following 5 days of cycling in an oscillating pH model (5 x 24-hour periods, each comprised of 3 x 20-minute acid challenges [pH 4.8], intervening time at neutral pH; solutions supersaturated with respect to hydroxyapatite at pH 7.4, undersaturated at pH 4.8). Histograms show net mineral gain by lesions treated with the self-assembling peptides after 5 days of cycling, compared with untreated controls, and mineral loss/gain during periods at low pH compared with intervening periods at neutral pH. Results show mean values of 8 separate experiments ± SD. (b) Effect of treatment with a self-assembling peptide on mineral loss/gain by caries-like lesions of human enamel during each 24-hour period of 5 days’ cycling in an oscillating pH model (5 x 24-hour periods, each comprised of 3 x 20-minute acid challenges [pH 4.8], intervening time at neutral pH; solutions supersaturated with respect to hydroxyapatite at pH 7.4, undersaturated at pH 4.8). Histograms show net mineral gain by lesions treated with the self-assembling peptides compared with untreated controls. Results show mean values of 8 separate experiments ± SD.