Xenogenic collagen matrix or autologous connective tissue graft as adjunct to coronally advanced flaps for coverage of multiple adjacent gingival recession: Randomized trial assessing non-inferiority in root coverage and superiority in oral health-related quality of life

AimTo evaluate the non-inferiority of the adjunct of a xenogeneic collagen matrix (CMX) or connective tissue graft (CTG) to coronally advanced flaps (CAF) for coverage of multiple adjacent recessions and compare superiority in patient-reported outcomes (PROM). Material and methodsOne hundred and eighty-seven subjects (92 CMX) with 485 recessions in 14 centres were randomized and followed up for 6months. Patients filled daily diaries for 15days to monitor patient-reported experience. The primary outcome was changed in position of the gingival margin. Multilevel analysis used centre, subject and tooth as levels and baseline parameters as covariates. ResultsAverage baseline recession was 2.51.0mm. The surgery was 15.7min shorter (95%CI from 11.9 to 19.6, p<.0001) and perceived lighter (11.9 VAS units, 95%CI from 4.6 to 19.1, p=.0014) in CMX subjects. Time to recovery was 1.8days shorter in CMX. Six-month root coverage was 1.7 +/- 1.1mm for CMX and 2.1 +/- 1.0mm for CTG (difference of 0.44mm, 95%CI from 0.25 to 0.63mm). The upper limit of the confidence interval was over the non-inferiority margin of 0.25mm. Odds of complete root coverage were significantly higher for CTG (OR=4.0, 95% CI 1.8-8.8). ConclusionReplacing CTG with CMX shortens time to recovery and decreases morbidity, but the tested generation of devices is probably inferior to autologous CTG in terms of root coverage. Significant variability in PROMs was observed among centres.