Effect of Different Remineralizing Agents on Streptococcus mutans and Actinomyces-mediated Demineralization in Primary and Young Permanent Teeth: An In-vitro Oral Disease Model.

AIM: To evaluate and compare the effects of silver nanoparticles, self-assembling peptide, casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), and green tea polyphenols on microbial viability and enamel demineralization in primary and young permanent teeth extracted for therapeutic reasons, including severe caries, orthodontic indications, or trauma.

MATERIALS AND

METHODS

Ninety-eight extracted human teeth were included in the study, comprising 49 primary and 49 young permanent teeth. The samples were randomly allocated into four groups based on the remineralizing agent used: Group I-Silver nanoparticles (n = 25), Group II-Self-assembling peptide (n = 24), Group III-CPP-ACP (n = 24), and Group IV-Green tea polyphenols (n = 25). A standardized dual-species biofilm model of Streptococcus mutans and Actinomyces spp. was established to simulate cariogenic challenge. Post-treatment evaluation included surface microhardness testing and colony-forming unit (CFU) analysis. Statistical analysis was performed using appropriate parametric tests, with a significance level of p < 0.05.

RESULTS

Silver nanoparticles showed the highest mean surface microhardness of 312.45 Vickers hardness number (VHN) and the lowest microbial counts for both S. mutans (1.12 ×102/mL) and Actinomyces (1.28 ×105/mL). Self-assembling peptide demonstrated the second-highest microhardness (295.30 VHN) and microbial reduction (S. mutans 1.65 ×102/mL, Actinomyces 1.74 ×102/mL), followed by CPP-ACP (278.15 VHN; S. mutans 2.10 ×102/mL, Actinomyces 2.24 ×102/mL) and green tea polyphenols (265.40 VHN; S. mutans 2.35 ×102/mL, Actinomyces 2.48 ×102/mL). The descending order of efficacy was silver nanoparticles > self-assembling peptide > CPP-ACP > green tea polyphenols, with significant differences among all groups.

CONCLUSION

Silver nanoparticles exhibited superior antimicrobial and remineralization efficacy, followed by self-assembling peptides, CPP-ACP, and green tea polyphenols, confirming variable effectiveness of contemporary remineralizing agents on primary and young permanent teeth under cariogenic challenge.

CLINICAL SIGNIFICANCE: Dental caries remains a major concern in primary and young permanent teeth due to immature enamel and high susceptibility to biofilm-mediated demineralization. This study provides a comparative framework for selecting clinically effective remineralizing agents. The findings support the evidence-based translation of in-vitro results into preventive and minimally invasive strategies for enhancing enamel resistance and controlling cariogenic biofilms in pediatric and adolescent patients.