CORREELATION BETWEEN MICRO-HARDNESS AND MINERAL CONTENT IN THE HEALTHY TOOTH ENAMEL OF HUMANS BELONGING TO DIFFERENT AGE GROUPS

Objective: To find a linear relationship between micro-hardness and mineral content of the healthy tooth enamel which is particularly important in the clinical context. Study Design: In-vitro experimental study. Place and Duration of Study: This study was carried out at the Pakistan Institute of Engineering and Applied Sciences (PIEAS), from Jan 2019 to Mar 2019. Methodology: This study was performed in-vitro in an experimental research laboratory with a controlled time series design. A total of 32 upper central incisors belonging to different age groups ranging from 21-60 years were extracted and categorized into four groups. The groups were named as A=21-30 years, B=31-40 years, C=41-50 years and D=51-60 years. The teeth of different age groups were utilized to make enamel specimens of 4 mm x 6 mm in poly-acrylic cylinders of 2 cm width and 3 cm height. These enamel specimens were finely polished. The enamel specimens were then evaluated for micro-hardness utilizing a Vickers micro-hardness tester. Eventually, the mineral content was analyzed with the help of energy dispersive x-ray spectroscopy. After that, the data attained was then assessed with a one-way analysis of variance. Results: Tooth enamel of the younger age group ranging from 21-30 years exhibited the lowest Vickers micro-hardness and the mineral content. The level of Vickers micro-hardness and mineral content increased accordingly with age and was found to be highest in the tooth enamel of older age group ranging from 51-60 years. Conclusion: The results demonstrated that the hardness of tooth enamel increases with age and is directly related to the mineral content