PurposeThe in vivo wear resistance of 12 composite resins were compared with an amalgam control using the Latin Square experimental design. Sixteen edentulous patients wearing specially designed complete dentures formed the experimental population.Materials and MethodsThe Michigan Computer Graphics Measurement System was used to digitize the surface of the control and composite resin samples before and after 3‐month test periods to obtain wear data. The 12 composite resins selected for this investigation based on their published composite classification types were seven fine particle composites, three blends, and two microfilled composite resins. The Latin Square experimental design was found to be valid with the factor of material being statistically different at the 5% level of significance. Wear was computed as volume loss (mm3/mm2), and all of the composites studied had more wear than the amalgam control (P= .001).ResultsAfter 3 months, the mean (error) of wear of the amalgam was 0.028 (0.006). Means (error) of wear for the 12 composites were ranked from most to least wear by mean wear volume loss.ConclusionsThe absence of any relationship between mean wear volume loss and the volume percentage filler was confirmed by the correlation coefficientr= ‐0.