Chemical and crystallographic study of remineralized surface on initial carious enamel treated with Galla chinensis

Abstract

To investigate the morphologic, chemical and crystallographic characters of remineralized surface on initial carious enamel treated with Galla chinensis, scanning electron microscopy equipped with energy dispersive analysis spectroscopy were used, and X-ray microdiffraction (microzone XRD) was used for the first time to analyze in situ the microzone crystallite of remineralized surface on carious enamel. Bovine sound enamel slabs were demineralized to produce initial carious lesion in vitro. Then, the lesions were exposed to a pH-cycling regime for 12 days of remineralization. Each daily cycle included 4x1 min applications with one of the three treatments: distilled and deionized water (DDW); 1 g/L NaF; 4 g/L G. chinensis extract (GCE). After the treatments, some rod-like deposits and many irregular prominences were found on GCE-treated enamel surface, and the intensities of Ca and P signals showed a tendency to increase; Ca:P ratio was significantly higher than that of DDW-treated enamel. X-ray microdiffraction showed hydroxyapatite was still the main component of GCE-treated enamel, and the crystallinity was increased, the crystal lattice changed gently with decreased lattice parameter a. These results indicated the potential of GCE in promoting the remineralization of initial enamel carious lesions, and supported the previous hypothesis about GCE mechanism. Combined with the anti-bacteria and demineralization inhibition properties of GCE, the natural G. chinensis may become one more promising agent for caries prevention.

Effects of gallic acid on the morphology and growth of hydroxyapatite crystals

“…Some studies showed that the chemical compounds of Galla chinensis could regulate the demineralization/remineralization balance by influencing the morphology, structure and chemical content of enamel crystals. 12,13 The special physicochemical property of polyphenols may assist during the modulation of biomineral crystal growth. Some studies indicated that natural polyphenol compounds, usually found in our food and drink, can efficiently modulate the growth of biominerals.…”

Comparison of Chemical Elements on Carious & Normal Premolar’s Enamel Layers Using Energy Dispersive X Ray Spectrometer (X Ray-EDS)

“…The O was not modified in both carious and normal enamel layers ( Table 1). Although, the remineralization produced by hydroxyapatite consists in a deposition of a new apatite mineral into the eroded enamel surface scratches, carious surface [31] [37]. Acid attack is one of the major causes of enamel hydroxyapatite loss [25] [27].…”

Anti-carious Effects ofGalla chinensis: A Systematic Review

“…These findings seem to support the formation of an 'enamel organic matrix-G. chinensis-calcium' complex that affects the mineral ion deposition. The mechanism is probably mediated by GCEs that enhance the remineralization of caries enamel (Zhang et al, 2009d).…”