Comparison between different intervals (effect of time) Table 
Descriptive statistics of all groups regarding surface roughness at baseline, after one day, and after 14 days and comparison between different intervals within each group









Means with different superscript letters were significantly different as Means with the same superscript letters were insignificantly different as 
Line chart representing surface roughness changes in all groupsComparison between different intervals was performed by using the One-Way ANOVA test, which revealed a significant difference in all groups as In Omnichroma coffee O1 and Venus Peral Coffee V1, there was a significant difference between all intervals (significant increase as all with different superscript letters)In Omnichroma distilled water O2 and Venus Peral distilled water V2 there was an insignificant difference between baseline and after one day, while after two weeks was significantly the highest.