Transverse micro radiography analysis of the effect of experimental calcium-containing primer system on demineralized enamel

Abstract

Background: Enamel mineral density is dependent on a balanced dynamic process of demineralization and remineralization. Objective: We evaluated the remineralization potential of experimental calcium-containing primer (CaP) application on enamel subsurface lesions. Methods: Demineralized enamel samples obtained from bovine incisor teeth were prepared and cut buccolingually. All samples were divided into 4 main groups according to the type of primer: CLEARFIL SE BOND 2 Primer (SEP), experimental calcium-containing primer (CaP) and bond: CLEARFIL SE BOND 2 Bond (SEB), CLEARFIL Protect Bond (PBB) treatment: (1) SEP-SEB (2) SEP-PBB (3) CaP-SEB (4) CaP-PBB. Each group was subdivided according to storage time in artificial saliva: immediately, 1 month and 6 months. Then, the samples were analyzed using transverse micro radiography (TMR). Additionally, the samples treated with each primer were prepared for scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS) observation. Two-way ANOVA was used for the statistical analysis of mineral loss (∆Z: vol%·µm). Results: CaP-PBB had the significantly lowest ∆Z at all storage times, while SEP-SEB had the highest ∆Z (p < 0.05). SEM observations revealed that new crystals were formed on the surface after 6 months, and the ratio of calcium on the enamel increased in the EDS analysis. Conclusion: Experimental calcium-containing primer can provide additional mineral deposition, with even further deposition when combined with a fluoride-containing bond.