Postoperative Study of Bone Gain in Mandibular Alveolar Bone Reconstructed with Screw-Guided Bone Regeneration Technique and Porcine-Derived Xenograft in 42 Edentulous Patient Candidates for Implant-Prosthetic Therapy

Doriana Agop-Forna,Bianca Törok,David M Dohan Ehrenfest,Carmen Gabriela Stelea,Raluca Dragomir,Cristina Dascălu,Roland Törok

doi:10.3390/app11219826

Doriana Agop-Forna, Bianca Törok + Show 5 more

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https://doi.org/10.3390/app11219826

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Abstract

This study aimed to test whether alveolar bone gain (width and osteodensity) in mandible implant sites, augmented by the screw-guided bone regeneration (S-GBR) technique and the porcine-derived xenograft, differ from that of the mandible sites reconstructed with S-GBR and the bovine-derived xenograft. Materials and method. A total of 42 edentulous patients (mean age 54.60 ± 14.90) were randomly divided into a test group (S-GBR + porcine-derived xenograft) and a control group (S-GBR + bovine-derived xenograft). The immediate implants were placed simultaneously with grafting procedures. The implant site width was measured before teeth extractions and 6 months after the augmentation procedures. Osteodensity bone values were evaluated immediately after the implant placement and at 6 months follow-up. The CBCT sections and Sidexis XG/DVT (Densply/Sirona) software were used to evaluate the changes of the width in the augmented alveolar bone. The NNT Viewer/CT (NewTom) software was used to record the osteodensity changes. Statistical comparisons between the groups were performed by the Mann–Whitney and t-tests (significance level p < 0.05). Results. The mean values of the bone gain at 6 months follow-up (control group vs. test group) were as follows: width (4.107 mm vs. 4.1624 mm); osteodensity (276.83 HU vs. 254.24 HU). The statistical analysis found the absence of statistically significant differences between the two groups regarding the bone gain (width and osteodensity) at 6 months after the augmentation and the immediate implant placement. Conclusions. The horizontal bone and osteodensity gains in the porcine-derived group were similar and without significant statistical differences when compared with the implant sites reconstructed with the bovine-derived xenografts group at 6 months postoperatively. The reconstruction of the mandibular alveolar bone by the S-GBR technique and the porcine-derived xenografts is a valid bone regeneration strategy for edentulous patients with moderate/severe horizontal resorption of the mandibular alveolar bone.

Highlights

At the level of the mandibular areas, the insertion of short or small diameter dental implants at the level of the implant sites with severe resorption does not allow for the adequate reconstruction of the alveolar ridge volume and morphology and reduces the success rate of implant-prosthetic restorations [2]
Considering the difficulties related to the maintenance of the stability of the grafted areas affected by severe horizontal and vertical resorptions, Screw-Guided Bone Regeneration (S-GBR) ensures tenting mechanisms that can prevent the collapse of the soft tissues and of bone resorption [12]
In a recent study with 24 months follow-up, we demonstrated the validity and effectiveness of this technique when used with a bovine-derived xenograft [13]

Summary

Introduction

It is estimated that up to 50% of all implant procedures performed in the coming years will involve the use of bone grafts [5] In this context, the reconstruction of the implant sites through the various guided bone regeneration techniques is an important stage of the implant-prosthetic treatment to restore the aesthetic parameters and the optimal functioning of the stomatognathic system [6,7]. We applied the S-GBR technique mostly to patients with anterior and posterior mandibular severe horizontal resorption by using a combination of autogenous bone and xenograft materials, and resorbable collagen membranes. Despite the numerous studies investigating the alveolar bone augmentation with xenografts of bovine origin, only a few have investigated the predictability and stability of the functional and aesthetic outcome following alveolar bone regeneration procedures with porcine-derived xenografts. Other benefits of the porcine-derived xenografts are the similar anatomical, physiological, and genetic structure to human bone tissue, and the low risk of transmission of diseases from pig to human [16,17]

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