- In tooth included in the study and the adjacent elements of the following must be observed: probing depth less than 3 mm; do not show bleeding on probing (periodontal health) and no insertion loss in the proximal and palatal areas; Provide formal consent to participate in research, after the explanation of the risks and benefits by an individual not involved in it (Resolution #196 October 1996 and the Code of Dental Professional Ethics - C.F.O. - 179/93).