Chemical composition of Galla chinensis extract and the effect of its main component(s) on the prevention of enamel demineralization in vitro

To determine the chemical composition of Galla chinensisextract （GCE） by several analysis techniques and to compare the efficacy of GCE and its main component（s） in inhibition of enamel demineralization, for the development of future anticaries agents, main organic composition of GCE was qualitatively determined by liquid chromatography-time of flight-mass spectrometry （LC-TOF-MS） and quantified by high-performance liquid chromatography-diode array detector （HPLC-DAD）. Inorganic ions were tested by inductively coupled plasma-atomic emission spectroscopy and F was especially measured by ion chromatography. Then, bovine enamel blocks were randomly divided into four treatment groups and were subjected to a pH-cycling regime for 12 times. Each cycle included 5-min applications with one of four treatments： 4g.L-1 GCE solution, 4g.L-1 gallic acid （GA） solution, I g.L-1 NaF solution （positive control）, deionized water （DDW, negative control）, and then 60-min application in pH 5.0 acidic buffer and 5-min application in neutral buffer. Acidic buffers were retained for calcium analysis. The main organic composition of GCE were GA and its isomer, and, to a lesser extent, small molecule gallotannins. The content of GA in GCE was 71.3%±0.2% （w/w）. Inorganic ions were present in various amounts, of which Ca was （136±2.82） μg.g-1, and Zn was （6.8±0.1） μg.g-1. No F was detected in GCE. in pH cycling, GA showed an effect similar to GCE in inhibiting enamel demineralization （P〉0.05）. GA was found to be the main effective, demineralization inhibiting component of GCE and could be a promising agent for the development of anticaries agents.

Factors Influencing Subjective Orthodontic Treatment Need and Culture-related Differences among Chinese Natives and Foreign Inhabitants

Aim The aim of this survey was to compare Chinese natives and foreign inhabitants in Chengdu, China, with respect to： （1） attitudes towards dental appearance, （2） subjective orthodontic treatment need, and （3） the main factors influencing orthodontic treatment need. Methodology A total of 522 subjects, including 227 foreign inhabitants and 295 Chinese natives in Chengdu participated in the survey. A simple random sampling method was adopted and a face-to-face interview was conducted at some public sites using a questionnaire. Data was entered by two persons synchronously using Epidata 3.0, and SPSS 13.0 was used to analyze these data. Results 89.0% of foreign inhabitants were satisfied with their teeth compared to only 46.8% of Chinese natives. Females were more dissatisfied with their teeth than males. Chinese natives put improving appearance as the top priority （55.9%） for seeking orthodontic treatment; however, in foreign inhabitants, the main reason for seeking treatment was to improve masticatory function（44.1%）, followed by ＂to be pretty＂ （35.2%）. The importance of well-aligned teeth and self-perception of psychosocial impact of malocclusion were the same two main factors influencing subjective orthodontic treatment need （P〈0.05） in foreign inhabitants and Chinese natives. Sub- jective orthodontic treatment need between the two target groups was significantly different （P〈0.05）. Conclusion （1） It was very common that Chinese natives were dissatisfied with their dental appearance, and their subjective orthodontic treatment needs were high. （2） There were some differences in orthodontic treatment motives between the two target groups. （3） There were differences in subjective orthodontic treatment needs between foreign inhabitants and Chinese natives. However, the prominent influential factors were almost the same. There may be benefit to understanding subjective orthodontic needs of different races.