The effect of vitamin D3 on enamel demineralisation and remineralisation: an in-vitro study / Mohd Zulfadli Harun

Dental caries is initiated as a white spot lesion on the enamel as an early sign of demineralisation. Enamel demineralisation is caused by acid production by oral bacteria. On the other hand, remineralisation is a process by which minerals return to the enamel to restore its strength and prevent tooth decay. Vitamin D is a fat-soluble vitamin that plays an important role in the mineralisation of bones and teeth by maintaining the appropriate levels of calcium and phosphorus ions in the blood. The potential remineralisation effect of vitamin D3 on enamel is still unknown. Hence, this research aims to investigate the effect of remineralisation of vitamin D3 on enamel microhardness, enamel surface morphology, enamel mineral and organic content, enamel density, and progression of caries lesion. The 45 extracted premolars were randomly divided into three groups: Group A (vitamin D3), Group B (5% sodium fluoride), and Group C (vitamin D3 and sodium fluoride). All samples were subjected to various evaluation methods such as microhardness testing, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Fourier Transform Infrared Spectroscopy (FTIR), and Micro CT. The evaluation was performed for three readings: baseline reading (before any treatment was given), demineralisation reading (after artificial caries lesions were created), and remineralisation reading (after pH cycling). During the pH cycling procedure, each sample was remineralised using the respective remineralising testing solution. Microhardness and mineral content (Ca and P weight%) were significantly reduced after demineralisation and significantly higher after remineralising solution application. The FTIR results verified the trend towards an increased mineral composition in the remineralised enamel. Meanwhile, the SEM image revealed the surface morphology of both demineralised and remineralised enamel differed across groups. Thin new formed crystallite layer following remineralisation with vitamin D3 was observed. While all remineralising treatments failed to increase enamel density significantly, differences in the progression of lesions between demineralised and remineralised enamel were noticeable. Therefore, the results of this study provide evidence that vitamin D3 has a positive impact on the remineralisation of enamel, which indicates that an improvement in the enamel's mechanical properties and morphological changes enhanced the remineralisation process and inhibited the progression of caries lesion.