Study On The Erosion Behavior And Factors Of Human Tooth Enamel

Human teeth are the one of the important organs in human oral cavity, which can significantly affect human facial beauty. As the beginning part of human digestive system, teeth are fundamental to ensure smooth food intake. However, due to the increasingly large consumption of acidic drinks and the vinegar especially for the people who are used to eat noodles in north China, dental erosion caused by acid attack has become more and more severe. Thus, it is very necessary to study the erosion behavior and mechanism of human teeth in acid medium. The results could enrich and develop biotribology, and provide theoretic guidance for tooth care and the improvement of eating habits in daily life.In this paper, the erosion behavior of human tooth enamel in different temperature citric acid solution (pH=3.20) was investigated in vitro, aiming to reveal the effect of acid medium temperature on tooth erosion. The surface morphology, nanomechanical and microtribological properties of acid-eroded human enamel were analyzed by means of various microscopic examinations, such as LCSM. SEM, nano-indentation/scratch tester, etc. In addition, this paper also explored the erosion behavior of human tooth enamel in three edible vinegar mediums:white vinegar, rice vinegar and aromatic vinegar.1. The erosion damage of human tooth enamel appeared to be aggravated as the temperature of acid medium increased. After being immersed in citric acid solution at a concentration of0.001mol/L for5min, the wear resistance of human enamel obviously decreased. With the acid medium temperature rising from20℃to60℃, the honeycomb-like structure on aid-eroded enamel surface became increasingly obvious and the degree of tooth erosion increased. Nano-indentation/scratch testing results showed that both the nanomechanical and microtribological properties of eroded enamel showed a strong dependence on erosion temperature. The indentation hardness and elastic modulus of enamel surface decreased after5min erosion in citric acid solution, and the decrease amplitude increased as the temperature of acid medium increased. Moreover, with the acid medium temperature rising from20℃to60℃, both the friction coefficient and scratch width and depth of eroded enamel surface increased. Increasing the temperature of acid medium could aggravate the damage of tooth microstructure and destroy its compactness, which would result in more channels of acid agent and then accelerate tooth erosion. Additionally, the increase of acid medium temperature might cause the decomposition of some organic matters within the enamel. As a result, the erosion damage of enamel increased with the increase of erosion temperature.2. It was found that obvious erosion occurred on the surface of enamel after5min erosion in three edible vinegar mediums:white vinegar, rice vinegar and aromatic vinegar. The erosion damage of enamel surface appeared to be most significant in white vinegar, followed by rice vinegar and aromatic vinegar.3. The results showed that when the pH value of acid medium was3.20. the enamel exhibited more obvious erosion damage in white vinegar than citric acid solution after5min erosion.