Background: The acidic pH, lactose content  and viscous nature  of whey protein beverages  might be a potential risk factor for the existing composite restorations in the oral cavity.

Objectives: To evaluate the effect of Whey Protein Concentrate (WPC), Whey Protein Isolate (WPI), Whey Protein Water (WPW)  and Distilled Water (DW) on the surface roughness of  four  restorative composites with different microstructures (Filtek Z 350XT,  Filtek Z 250XT, Filtek Bulk Fill and Filtek P 60).

Materials & methodology: Eighty disc shaped samples, 20 from each material were prepared and wet polished. On the basis of immersion in different Whey protein beverages, samples from each group were randomly divided into 4 subgroups. The immersion protocol was performed twice for  10 minutes in each Whey protein beverage followed by  immersion in artificial saliva for another 10 minutes for 30 days consecutively. Samples were stored in distilled water till the next cycle. The pre immersion and post immersion  surface roughness of all the samples were  recorded with acontact type surface profilometer. Data obtained were  statistically analysed using SPSS 25 software, unpaired  “t” test and Mann Whitney U test with the level of significance set at 5%.

Results & Conclusions: All dental composites exhibited significant rise in surface roughness post immersion in all Whey protein beverages but the maximum surface roughness changes were caused  by WPW followed by WPC and WPI.Filtek Z 250XT followed by  Filtek P 60 composites showed highest rise in surface roughness while Filtek Bulk Fill showed least rise in surface roughness

 

• Whey proteins, obtained from cow’s milk are an excellent source of branch chained amino acids.Nevertheless, they contain acidulants, carbohydrates (lactose) which can create an acidic environment in the oral cavity.
• As commercially available whey protein beverages are mildly acidic  and hygroscopic in nature, they pose potential risk to teeth and restorative materials.
• Different dental restorative materials behave differently when exposed to different types of whey protein beverages and this study emphasizes the effect of these beverages on surface roughness of composite resins.

Keywords: Filtek Bulk fill, Filtek Z 350XT, Filtek Z 250XT, P 60 Posterior composites, Surface roughness, Whey proteins