Study On The Prevention Of Dental Caries By Abalone Water-soluble Matter And The Preparation Of Hydroxyapatite With Inorganic Subtance Of Abalone Shell

Lianjiang county of Fuzhou city is ’Village of abalone in China’,the production of abalone has aways been maintaining at the first among the counties in China,and the annual output of abalone is more than ten thousand tons,A large number of abandoned abalone shells were produced after eating or processing by people.At present,the processing level of abalone shell is low,and only a small amount of abalone was used as Chinese herbal medicines and animal feed additive.Most of abalone shells were found abandoned on an island and around a town.This not only resulted in waste of natural resources,but also polluted the environment.Abalone shell is composed of less than 5%organic matter and more than 95%inorganic substance.The organic matter is mainly composed of protein,polysaccharide and pigment.The organic matter can be divided into the water-soluble organic matter(AWSIM)and the water-insoluble organic matter.Moreover,the AWSM has good biological activity,which can induce biomineralization and promote bone cell differentiation.The main inorganic substance is calcium carbonate,so abalone shell is a good source of calcium.In this paper,the organic matter and inorganic substance of abalone shell were developed and utilized,respectively.For the AWSM of abalone shell,the AWSM was extracted from abalone shell powders by different concentration of acetic acid.The composition of AWSM was analyzed.And the AWSM was used as active factor to explore the process of the tooth remineralization.The effects of the content of AWSM,the volume of the remineralization solution and the time of the remineralization on the process of tooth remineralization were investigated.For inorganic substance of abalone shell,we utilized abalone shell powders as a calcium source for hydroxyapatite(HAP).HAP was prepared by hydrothermal method from abalone shell powders.The effects of different hydrothermal conditions and surfactants on the synthesis of HAP were investigated.And we further studied the mechanism of HAP.The results of the study for AWSM show that the AWSM is composed of a small amount of protein and polysaccharide,and the content of the AWSM is different with different concentration of the acetic.When acetic acid concentration is 10%,the protein content was the highest,which was 1.53%.When acetic acid concentration is 30%,the polysaccharide content was the highest,which was 2.57%.It was found that the AWSM can efficient induce remineralization of HAP in vitro.Moreover,the remineralization effect of etched enamel is growing by increasing the content of the AWSM and prolonging the remineralization time.But,the effect of the volume of solution on remineralization was not significant.The results of the study for inorganic substance of abalone shell show that abalone shell powders can be converted to HAP nanoparticles via hydrothermal solid-state conversion and the fish scale-like,flower-like and typical hexagonal prosmatic structure of HAP were successfully achieved.The composition and morphology of the HAP can be regulated by different hydrothermal time,hydrothermal temperature and the pH value of the solution.Adding surfactants can promote formation of HAP,but the effect of surfactants on the morphology of HAP was small.This study provides a solution to the resource waste and environmental pollution caused by abandoned abalone shells.And it also provides a new way for the application of the abalone shell in the biological and pharmaceutical industry.