Xenogeneic collagen matrix versus connective tissue graft for buccal soft tissue augmentation at implant site. A randomized, controlled clinical trial

Peri-implant soft tissue may be critical to prevent inflammation and promote gingival margin stability. The purpose of this randomized clinical trial (RCT) is to compare xenogeneic collagen matrix (XCM) versus connective tissue graft (CTG) to increase buccal soft tissue thickness at implant site.Soft tissue augmentation with XCM (test) or CTG (control) was performed at 60 implants in 60 patients at the time of implant uncovering. Measurements were performed by a blinded examiner at baseline, 3 and 6 months. Outcome measures included buccal soft tissue thickness (GT), apico-coronal keratinized tissue (KT), chair time and post-operative discomfort. Visual Analogue Scale (VAS) was used to evaluate patient satisfaction.After 6 months, the final GT increase was 0.9 ± 0.2 in the XCM group and 1.2 ± 0.3 mm in the CTG group, with a significant difference favouring the control group (0.3 mm; p = .0001). Both procedures resulted in similar final KT amount with no significant difference between treatments. XCM was associated with significant less chair-time (p < .0001), less post-operative pain (p < .0001), painkillers intake (p < .0001) and higher final satisfaction than CTG (p = .0195).CTG was more effective than XCM to increase buccal peri-implant soft tissue thickness.