Autologous connective tissue graft or xenogenic collagen matrix with coronally advanced flaps for coverage of multiple adjacent gingival recession. 36-month follow-up of a randomized multicentre trial

Aim: To report the 36-month follow-up of a trial comparing the adjunct of a xenogenic collagen matrix (CMX) or connective tissue graft (CTG) to coronally advanced flaps (CAF) for coverage of multiple adjacent recessions. Material and methods: 125 subjects (61 CMX) with 307 recessions in 8 centres from the parent trial were followed-up for 36 months. Primary outcome was change in position of the gingival margin. Multilevel analysis used centre, subject and tooth as levels and baseline parameters as covariates. Results: No differences were observed between the randomized and the follow-up population. Average baseline recession was 2.6 ± 1.0 mm. 3-year root coverage was 1.5 ± 1.5 mm for CMX and 2.0 ± 1.0 mm for CTG (difference of 0.32 mm, 95% CI from −0.02 to 0.65 mm). The upper limit of the confidence interval was over the non-inferiority margin of 0.25 mm. No treatment differences in position of the gingival margin were observed between 6- and 36-month follow-up (difference 0.06 mm, 95% CI −0.17 to 0.29 mm). Conclusion: CMX was not non-inferior with respect to CTG in multiple adjacent recessions. No differences in stability of root coverage were observed between groups and in changes from 6 to 36 months. Previously reported shorter time to recovery, lower morbidity and more natural appearance of tissue texture and contour observed for CMX in this trial are also relevant in clinical decision-making.