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Hydroxyapatite 62 ) is the main component of enamel , and is responsible for the bright white appearance and elimination of the diffuse reflectivity of light by closing the small pores of the enamel surface .
 material: Hydroxyapatite 62; machine or equipment: component; material: enamel; machanical property: pores; material: enamel
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
Answer:
 material: Hydroxyapatite 62; machine or equipment: component; material: enamel; machanical property: pores; material: enamel