Zinc-Containing Restorations Create Amorphous Biogenic Apatite at the Carious Dentin Interface: A X-Ray Diffraction (XRD) Crystal Lattice Analysis

Abstract

The aim of this research was to assess the ability of amalgam restorations to induce amorphous mineral precipitation at the caries-affected-dentin substrate. Sound and cariesaffected dentin surfaces were subjected to both Zn-free and Zn-containing dental amalgam restorations. Specimens were submitted to thermocycling (100,000cy/5 ºC-55 ºC, 3 months).Dentin surfaces were studied by atomic force microscopy (AFM/nano-roughness), X-ray diffraction (XRD 2 ), field emission electron microscopy (FESEM) and energy-dispersive analysis (EDX), for physical and morphological surface characterization. Zn-containing amalgam placement reduced crystallinity, crystallite size and grain size of calcium phosphate crystallites at the dentin surface. Both microstrain and nanoroughness augmented in cariesaffected dentin restored with Zn-containing amalgams. Caries-affected dentin showed the shortest mineral crystallites (11.04 nm), when Zn-containing amalgams were used for restorations, probably leading to a decrease of mechanical properties which might favor crack propagation and deformation. Sound dentin restored with Zn-free amalgams exhibited a substantial increase in length of grain particles (12.44 nm) embedded into dentin crystallites.Zn-containing amalgam placement creates dentin mineralization and the resultant mineral was, utterly, amorphous in nature. Amorphous calcium phosphate will provide a local ion-rich environment which is considered favorable for in situ generation of prenucleation clusters, succeeding further dentin remineralization.

Comparison of Morphological Characteristics and Determination of Different Patterns for Rubber Particles in Dandelion and Different Rubber Grass Varieties

“…Our proteomics results also revealed that SRPs might play more important roles than LRPs for NRB in H. brasiliensis [ 8 ]. Laticifer cells were considered to originate from a series of cells united by dissolution of intervening walls [ 35 ]. It was reported that in TKS seedlings, as early as 10 days after germination, small rubber particles start to form in the laticifer cells, and these rubber particles have similar morphological patterns to those in other rubber-producing plants, such as H. brasiliensis and Parthenium argentatum [ 35 ].…”