FIGURE 1.

(a,b) Outline of the study: (a) View of the PTFE specimens directly applied onto the teeth surfaces. Test membranes are visible on the left side and the control membranes on the right side (experimental protocol n°1) at baseline, 4 hr, and 24 hr before retrieval. Two protocols were followed where test and control were randomized to left or right side of the mouth; (b) sampling protocol including the retrieved samples and associated analytical techniques at baseline, 4 hr, and 24 hr. One test and one control membrane were retrieved per volunteer and time point for colony‐forming units (n = 12) and confocal laser scanning microscopy (n = 12). One test and one control membrane were retrieved per volunteer at either 4 hr (n = 6) or at 24 hr (n = 6) for scanning electron microscopy analysis