Reconstructive surgical therapy of peri-implant defects with ribose cross-linked collagen matrix and crosslinked hyaluronic acid - a prospective case series

Abstract

Objective: To investigate the efficacy of ribose-crosslinked collagen (RCLC) matrices functionalized by crosslinked hyaluronic acid (xHya) for reconstructive treatment of class I and III (b-c) peri-implantitis lesions in a transmucosal healing mode.

Materials and methods: Thirteen patients presenting with 15 implants were included in this prospective case series. Upon flap reflection, the implants were thoroughly decontaminated employing glycine powder air polishing and adjunctive sodium hypochlorite. For defect augmentation, xHyA was administered to the bony defect walls, exposed implant surfaces, and the RCLC matrix before defect grafting. The full-thickness flap was readapted and sutured around the implant neck for transmucosal healing. Baseline and respective values at the 12 months post-op evaluation were recorded for the clinical parameters peri-implant probing depth (PPD), buccal soft tissue dehiscence (BSTD) and bleeding on probing (BoP). Furthermore, two independent investigators analyzed radiographic changes in the defect area. The mean changes for all variables were analyzed with a paired t-test.

Results: The initial mean PPD was 7.2 ± 1.9 mm, and BoP was present in 63% of sites. After 12 months, PPD at the latest visit was 3.2 ± 0.66 mm, which amounted to a respective 3.9 ± 1.85 mm reduction, while the BoP frequency dropped to 10% at all sites. Radiographic bone fill was accomplished for 62.8% of the former defect area, accompanied by a mean MBL gain of 1.02 mm around the treated implants (all p < 0.001).

Conclusions: Within the limits of this case series, we conclude that the proposed treatment sequence substantially improved peri-implant defects and offered a simplified but predictive technique.

Clinical relevance: Reconstructive treatment approaches for peri-implantitis are effective but remain non-superior to open flap debridement. Further research on novel biomaterial combinations that may improve reconstructive treatment outcomes are warranted. Ribose-crosslinked collagen matrices biofunctionalized by hyaluronic acid used in this study yield improved clinical and radiographic peri-implant conditions after 12 months.

Keywords: Crosslinked hyaluronic acid; Decontamination; Hypochlorite/aminoacid gel; Peri-implant defect; RCLC; Reconstructive surgery; xHyA.

Fig. 1

Schematic representation of the proposed workflow. After flap reflection, implants exhibiting intrabony defects (A) are thoroughly decontaminated using sodium hypochlorite gel (B) and glycine air powder abrasion (C). The decontaminated implant surfaces (D), as well as the defect, are coated with xHya (E). The glycation cross-linked collagen matrix provides both an osteoconductive scaffold and a barrier from the soft tissues (F)

Fig. 2

Case illustration for the proposed treatment protocol. (A) Implants presenting with PD > 8 mm and suppuration. (B) Full-thickness flap elevated using modified papilla preservation technique. (C) xHya-functionalized crosslinked collagen matrix applied to the defect. (D) Sutures in place. (E-H) One-year post-op, the implant exhibits no signs of inflammation or increased PPD. (I-J) X-Rays of the preoperative situation and one year postoperative

Fig. 3

Bland-Altman plot for the interrater reliability of two investigators who analyzed radiographic images. Blue dots represent the deviation from the mean of both measurements. The dotted lines represent 95% limits of agreement

Fig. 4

Mean PPD (a) and BOP (b + c) values. ****p < 0.0001

Fig. 5

Mean marginal bone level (a) and defect area fill (b) by periapical x-ray analysis. ****p < 0.0001