 Thirty-two subjects divided into type 2 diabetes mellitus and non-diabetic controls, having at least one functional implant and six teeth, were enrolled in a 1-year longitudinal investigation. Analyses of clinical measurements and standardized intra-oral radiographs, saliva and serum biomarkers via protein arrays for 20 selected markers, and plaque biofilm via qPCR for eight periodontal pathogens were performed at baseline and 1 year. In addition, the subjects were asked to respond to questionnaires to assess behavioral and psychosocial variables. 