Randomized controlled clinical study comparing a volume‐stable collagen matrix to autogenous connective tissue grafts for soft tissue augmentation at implant sites: linear volumetric soft tissue changes up to 3 months

Abstract Aim To test whether or not the use of a volume‐stable collagen matrix ( VCMX ) results in soft tissue volume increase at implant sites non‐inferior to an autogenous subepithelial connective tissue graft ( SCTG ). Methods In 20 patients, soft tissue augmentation at implant sites was performed using VCMX or SCTG . Casts obtained prior to augmentation ( BL ), at 30 ( FU ‐30) and 90 days ( FU ‐90) were digitized and transferred to stereolithography ( STL ) files. BL , FU ‐30 and FU ‐90 STL files were superimposed and linear volumetric changes evaluated in crestal and buccal regions of interest ( ROI ). Descriptive analysis was computed for both groups and a test for non‐inferiority was performed. Results The median linear changes from BL to FU ‐90 in the crestal ROI amounted to 0.175 mm (0.06; 0.51) for VCMX ( p = 0.002 over time) and to 0.51 mm (0.23; 0.94) for SCTG ( p = 0.129). The differences between the two groups were not significant ( p = 0.287). The respective values in the buccal ROI were 0.59 mm (0.26; 1.06) for VCMX ( p = 0.002) and 0.94 mm (0.66; 1.13) for SCTG ( p = 0.004). The differences between the two groups were not significant (crestal: p = 0.287; buccal: p = 0.534). Non‐inferiority could be concluded for VCMX compared to SCTG for both ROI . Conclusion VCMX and SCTG can be used for soft tissue augmentation at implant sites resulting in an at least short‐term increase in volume.