The aim of the work is to provide a detailed description of grinding and dressing, focusing on definitions, involved phenomena during the operations, different kind of machines and main variables to know for complete understating of the processes. A state of the art on previous tests carried out by Malkin, Murray and Salmon on effects of rotary dressing on grinding wheels performances is presented as well as a definition of Aggressiveness number in finishing processes and studies on utility of acoustic emission signal monitoring during dressing, by Badjer et al. By carrying on the mentioned experiments and expanding the studies to new evaluations, the purpose is to analyse effects of plunge-roll diamond dressing on vitrified grinding wheels performances, establish dressing Aggressiveness number importance in industry for monitoring thermal damage and speeding-up the process (clear correlations between dressing and grinding variables and dressing Aggressiveness number have been noticed), prove the possibility of wheel sharpness assessment and the acoustic emission signal monitoring relevance in dressing.