Chicken eggshell paste versus CPP-ACP for enamel remineralization: a pilot in vitro study using micro-computed tomography

Dental caries in primary teeth affects over 80% of children in many developing countries. Minimal intervention focuses on enamel remineralization. CPP-ACP is widely used, but chicken eggshells, a calcium carbonate-rich biowaste, may offer a sustainable, low-cost alternative. To compare the remineralization potential of chicken eggshell paste versus CPP-ACP on induced white spot lesions in primary enamel using micro-CT. This pilot in vitro pretest–posttest study used consecutive sampling ( n = 3/group). Nine primary incisors with induced lesions were assigned to chicken eggshell paste, CPP-ACP, or negative control. Samples underwent pH cycling. Micro-CT assessed demineralization depth and mineral density pre- and post-treatment. Data were analyzed using mixed ANOVA, paired t-tests with Bonferroni correction ( p < 0.017), and one-way ANOVA with Tukey HSD. Data were normally distributed ( p > 0.05). Mixed ANOVA revealed significant time×group interactions for depth (F(2,6)=431.53, p < 0.001) and density (F(2,6)=23.90, p = 0.001). Both eggshell paste (depth: 130.85 ± 2.06 µm, p < 0.001; density: 15.76 ± 3.78, p = 0.019) and CPP-ACP (depth: 102.76 ± 9.98 µm, p = 0.003; density: 13.58 ± 2.82, p = 0.014) significantly improved from baseline, while controls worsened in depth (−3.24 ± 0.66 µm, p = 0.014). Eggshell paste reduced depth more than CPP-ACP (mean difference: 28.09 µm, p = 0.003), but both were comparable for density ( p = 0.618). Both treatments outperformed controls ( p < 0.01). Chicken eggshell paste demonstrated remineralization efficacy comparable to CPP-ACP, supporting its potential as a sustainable alternative for early caries management in primary teeth.