Enhanced alveolar ridge preservation with hyaluronic acid-enriched allografts: a comparative study of granular allografts with and without hyaluronic acid addition

Abstract

Purpose: Ridge preservation is essential to restore alveolar ridge volume and to enhance esthetic and functional outcomes for dental implants. The addition of hyaluronic acid to allogeneic bone substitute materials might enhance these outcomes. This clinical study evaluated the efficacy of ridge preservation after tooth extraction using granular allografts with and without hyaluronic acid addition.

Methods: In this retrospective study, 40 patients with compromised extraction sockets were enrolled. Among them, 19 received particulate allogeneic bone substitutes (Allo), 21 received allogeneic bone substitutes with hyaluronic acid (AlloHya). Vertical and horizontal graft stability, graft shrinkage rate, and bone mineral density were assessed using radiographic measurements on CBCT scans conducted before tooth extraction, directly after ridge preservation and after four months. Patients were followed up 12 months post-implantation.

Results: Vertical height loss after 4 months was significantly greater in the Allo group (-0.82 ± 0.95 mm) compared to the AlloHya group (-0.19 ± 0.51 mm; p = 0.011). Graft shrinkage rate was 16.9 ± 11.5% (Allo) and 10.3 ± 7.7% (AlloHya) (p = 0.038). After four months, average bone density was significantly higher in the AlloHya compared to the Allo group (p = 0.004). Nearly all implants (39 out of 40) were classified as "Success" according to the ICOI scheme, with no differences in implant quality between the two study groups.

Conclusions: Improved graft stability, reduced resorption, and increased bone density were observed in hyaluronic acid-enriched allografts compared to pure allografts. Adding hyaluronic acid to allogeneic bone grafts significantly enhanced outcomes in ridge preservation.

Keywords: Allogeneic bone material; Dental implants; Extraction sockets; Hyaluronic acid; Regenerative dentistry; Socket preservation; maxgraft®.

Fig. 1

Initial clinical situation. The sectional image of the CBCT, along with the recession on tooth 11, reveals a class III defect according to Kim et al. [3]. The mucosa appears inflamed, and an extensive loss of the buccal alveolar wall is visible

Fig. 2

Hyaluronic acid enriched allograft. Figure C shows the allogenic granules mixed with powdered hyaluronic acid. Adding sterile NaCl solution (Figure D) produces a moldable mass known as “sticky bone” (Figure E)

Fig. 3

Alveolar ridge preservation. Tooth extraction (Figure F) revealed apical granulation. After mechanical cleaning, the socket was filled with allogenic bone substitute mixed with hyaluronic acid (Figure G). To optimize soft tissue healing, a PRF plug was placed in the socket and secured with a situational suture (Figure H). The postoperative control image (Figure I) shows the vestibular oversizing of the inserted material

Fig. 4

Final situation. After 4 months, when the surgical site was reopened (Figure J), a completely regenerated alveolar ridge was revealed. The alveolus showed complete radiological regeneration (Figure K), allowing for straightforward implant placement. Figure L illustrates the final prosthetic restoration with irritation-free mucosa conditions after one year

Fig. 5

3D-Model for visualizing the mathematical approach of calculating the volume of the defect