Remineralization and antimicrobial bioactivities of a Sn-CPP-ACFP nanocomplex

To investigate the remineralisation and antimicrobial bioactivities of a novel Sn-CPP-ACFP nanocomplex.

Sn-CPP-ACFP was prepared from 10% CPP-ACP and 29 mM SnF₂ (1100 F). Enamel and dentine remineralisation was measured using an in situ assay where participants wore removable appliances containing human enamel and dentine blocks with subsurface lesions. Participants were randomly assigned to rinse with a 1 in 5 diluted solution containing SnF₂ (SF) or Sn-CPP-ACFP (CPPSF) for one min, four times a day, for 14 days. Post-treatment saliva samples were collected and analysed for bioavailable ions. At the end of each treatment period, the enamel and dentine blocks were removed and compared to untreated controls. The blocks were assessed for percent surface microhardness recovery (%SMHR) and remineralisation by transverse microradiography. The antimicrobial activity of Sn-CPP-ACFP was measured using Porphyromonas gingivalis (Pg) and Streptococcus mutans (Sm) with an agar diffusion assay.

CPPSF was superior in inhibiting growth of Pg at pH 7.0 and Sm at pH 7.0 and pH 5.5 which correlated with the CPP's ability to solubilise and stabilise Sn ions. Furthermore, CPPSF (35.9 ± 1.5%) produced significantly (p < 0.001) higher remineralisation than SF (15.9 ± 1.1%) in enamel and in dentine (CPPSF 37.9 ± 2.5%; SF 21.9 ± 2.3%). Similar findings were observed for the %SMHR measurements with CPPSF 38.2 ± 8.7% and SF 4.7 ± 3.0%. Post-rinse saliva analysis revealed significantly higher Ca and Sn ion levels in saliva after CPPSF compared with SF. SEM analysis showed that CPPSF was more efficient than SF at occluding dentine tubules.

The novel Sn-CPP-ACFP nanocomplex enhanced remineralisation and antimicrobial efficacy compared with SF.