Staining effect of various beverages on and surface nano-hardness of a resin coated and a non-coated fluoride releasing tooth-coloured restorative material: An in-vitro study

OBJECTIVE: The objective of this study was to compare staining effect of various beverages on and surface nano-hardness of a resin coated and a non-coated fluoride releasing tooth-coloured restorative material. MATERIALS AND METHODS: Two restorative materials, Equia Forte Fil (coated with Equia Forte Coat) and Cention N (non-coated), were evaluated in this study. Fifty samples (n = 50) were prepared from each restorative material. Ten samples of each material were randomly placed in Phosphate Buffer Saline (PBS) solution, Tea, Coffee and Coke solutions. Spectrophotometer readings were recorded after 24 hours of sample preparation followed by 7th, 14th, 21st and 28th day. Colour difference (ΔE) for each sample was calculated at the specified time intervals. The remaining ten samples of each restorative material were subjected to nano-hardness testing. Nano-hardness values at 1st day and 28th day were noted. Colour difference and nano-hardness values were statistically analysed. RESULTS: By the 28th day, all samples from the solutions were stained. Equia Forte Fil coated with Equia Forte Coat samples showed better resistant to staining solutions than Cention N samples. Surface nano-hardness of both the materials increased from the 1st day to 28th day and were comparable. CONCLUSION: Over a period of time, changes in colour stability and nano-hardness, are inevitable. Cention N showed more potential to undergo surface discolouration than Equia Forte Fil. Both materials exhibited increased nano-hardness over a period of time. Cention N exhibited higher surface nano-hardness when compared to Equia Forte, by the 28th day. CLINICAL SIGNIFICANCE: Resin coated, high viscous and fluoride releasing glass ionomers can delay the staining effect by various beverages and exhibit better initial surface nano-hardness when compared to a non-coated alkasite based, fluoride releasing restoration.