Introduction: Dental caries is a prevalent chronic oral disease in children, driven by cariogenic bacteria,
frequent sugar intake, and poor oral hygiene. Early lesions can be managed noninvasively by remineralizing
agents to prevent progression. Fluoride is effective but has dose-related limitations and may form surface
barriers that impede subsurface remineralization. Aim: To compare the remineralizing effects of a 500 ppm
sodium fluoride + 2% arginine solution with and without 1% nano biogenic β-tricalcium phosphate (β-TCP)
derived from cuttlefish bone on demineralized premolar enamel. Methods: Seventy enamel halves from 35
premolars were allocated to five groups (n=14): Group I, sound enamel (control); Group II, demineralized;
Group III, demineralized treated with 500 ppm NaF; Group IV, demineralized treated with 500 ppm NaF +
2% arginine; Group V, demineralized treated with 500 ppm NaF + 2% arginine + 1% nano β-TCP. Each
group was split for surface microhardness (Vickers, n=7) and ESEM with EDX analysis (n=7). Results:
Demineralization significantly reduced surface microhardness and Ca:P ratio. All treatments increased
hardness and promoted surface repair; Group V achieved the greatest hardness recovery and the most
enamel-like, dense morphology. Fluoride content increased in Groups IV and V versus Group III. Group V
showed the highest Ca:P ratio, indicating superior mineral redeposition. Conclusion: Adding 1% nano
biogenic β-TCP to a fluoride–arginine formulation enhanced remineralization of demineralized enamel more
effectively than fluoride alone.