Remineralization Potential of Resin Composites Containing TEGDMA-Functionalized Calcium Phosphate Particles

Objectives: The aim of the study was to evaluate the effect of experimental composites containing dicalcium phosphate dihydrate (DCPD) particles on remineralization of artificial enamel lesions, as a function of particle content and functionalization with triethylene glycol dimethacrylate (TEGDMA).
Methods: Five composites containing equal parts (in mols) of BisGMA and TEGDMA and 60 vol% of fillers were manipulated. Filler phase was constituted by silanized barium glass (BG) and 0% (control), 10% or 20% (by volume) of DPCD particles, either non-functionalized (NF) or functionalized (F) with TEDGMA. Artificial subsurface lesions were produced in human enamel fragments (N=120) by immersing them in 30 ml of demineralization solution (pH 5.0) for 12 days at 37°C. Fragments were divided into six groups (n=20), according to the composite applied on the lesion: 60% BG, 20% DCPD NF, 20% DCPD F, 10% DCPD NF, 10% DCPD F plus an unrestored group (non treated, NT) and exposed to pH cycling (16 days, 4 h in demineralization solution/pH=5 and 20 h in remineralization solution/pH=7). Specimens were sectioned longitudinally and enamel mineral profile was evaluated using transverse microradiography (TMR) for lesion depth (LD, in µm) and integrated mineral loss (ΔZ, vol%.µm). ΔΔZ% [100x(ΔZ_initial – ΔZ_treatment)/ΔZ_initial] was used to estimate remineralization. Data were analyzed by Kruskal-Wallis/Dunn’s test (ΔΔZ) or one-way ANOVA/Tukey test (ΔΔLD, or percentage of LD reduction, alpha: 0.05 for all tests).
Results: Results are shown in the Table. All restored groups showed enamel remineralization, ranging from 3.3% to 23.0%. However, due to high data scattering (particularly in the BG group), no statistically significant differences in ΔΔZ or ΔΔLD were found. NT group showed further demineralization after pH cycling.
Conclusions: In conclusion, all composites containing DCPD particles were able to promote mineral recovery of the enamel lesion. Particle content or functionalization with TEGDMA did not affect remineralization.