Methods: Twenty patients (Miller Class I or II recession defects) were randomized to receive either ADMA-A or -B. Further randomization was done in the ADMA-B group regarding the orientation of the basement membrane (BM) of the graft, “toward” or “away from” the root surface. Clinical assessments of plaque index (PI), gingival index (GI), probing depth (PD), clinical attachment level (CAL), recession depth (RD) and width (RW), width of keratinized gingiva (KG), gingival thickness (GT1 and GT2) and width of immobile tissue (IT) were evaluated between baseline and 12 months postoperatively.
Results: PI, GI, PD, CAL and KG were comparable between groups. The average root coverage was 63% with ADMA-A and 81% with ADMA-B. The zone of IT extended apical to MGJ by a mean of 1.88mm in the ADMA-A group and 2.69mm in the ADMA-B group. No statistically significant differences were noted for the abovementioned parameters (Mixed model, P>0.05). Following the same statistical model, GT1 was only increased with ADMA-A by a mean of 0.92mm and placing BM “away from” rather than “toward” the defect resulted in a 1mm gain in IT and 0.59mm loss of GT1 in the ADMA-B group (P<0.05).
Conclusions: The use of either type of ADMA results in predictable root coverage. This study provides novel evidence on the presence and quantity of a zone of immobile tissue extending apical to MGJ. Hence, minimal or no KG at baseline should not preclude the use of ADMA.