Calcium phosphate polymer induced liquid precursor improves dentin bonding performance of primary teeth with dentinogenesis imperfecta type II

The current study aims to assess the dentin bonding performance of primary molars with dentinogenesis imperfecta type II (DGI-II). Moreover, we assess the efficacy of calcium phosphate polymer induced liquid precursor (Ca/P-PILP), a biomimetic remineralization material, in improving the resin bonding performance of DGI-II dentin. Dentin specimens from normal and DGI-II primary molars were treated with either Ca/P-PILP or double-distilled water. Morphology of these dentin specimens were observed using scanning electron microscopy (SEM), and the calcium and phosphorus contents were determined by energy-dispersive X-ray spectroscopy (EDS). Micro-tensile bond strength (µTBS) analysis was conducted to evaluate the resin bonding strength of dentin. SEM results showed that compared with normal dentin, DGI-II dentin exhibited significantly fewer dentinal tubules with nearly no intact tubular structures. Meanwhile, the dentin collagen fibers exhibited disorganized arrangement and compromised structural integrity. Compared with normal dentin, DGI-II dentin displayed inferior bonding performance with resin as shown by µTBS analysis, and EDS analyses showed that DGI-II dentin contained lower calcium and phosphorus contents. After treatment with Ca/P-PILP, the calcium and phosphorus contents of DGI-II dentin were significantly increased as shown by EDS analyses, and µTBS analysis showed that the bonding performance of DGI-II dentin was improved, while no notable effect was observed in normal dentin. Primary molars with DGI-II display structural defects and reduced calcium and phosphorus contents in dentin. The reduced mineral contents are partially responsible for the compromised bonding performance of DGI-II dentin, for Ca/P-PILP which effectively enhances the mineral contents of DGI-II dentin improves the resin bonding performance of DGI-II dentin.