Assessment of Vertical/Horizontal Ridge Augmentation in Atrophic Alveolar Ridge Using Autogenous Onlay Versus Inlay Grafting Techniques: A Systematic Review

TL;DR

This systematic review compares inlay and onlay grafting techniques for bone augmentation in atrophic alveolar ridges, finding inlay grafts more effective for stability and healing.

Contribution

The study provides a comparative analysis of inlay and onlay grafting techniques in alveolar ridge augmentation, highlighting inlay's advantages in clinical outcomes.

Findings

Inlay grafts showed better stability, less resorption, and improved soft tissue healing compared to onlay grafts.

Onlay grafts had higher resorption rates and complications, especially in vertical augmentations.

Inlay grafts benefit from better vascularization and mechanical protection within host bone.

Abstract

Alveolar ridge atrophy presents a major challenge in implant dentistry, often necessitating surgical augmentation to restore adequate bone volume for predictable implant placement. Among the various autogenous grafting approaches, the inlay and onlay techniques are widely utilized, yet their comparative clinical efficacy remains unclear. This systematic review aimed to evaluate the outcomes of vertical and horizontal ridge augmentation using inlay versus onlay grafting techniques in atrophic alveolar ridges. An extensive electronic and manual search of major databases was conducted in accordance with PRISMA guidelines, and eligible randomized controlled trials and comparative clinical studies assessing autogenous grafts were included. Six studies met the inclusion criteria. Both techniques produced appreciable gains in bone height and width; however, the inlay technique demonstrated more favorable results in terms of graft stability, reduced volumetric resorption, and improved soft tissue healing. Inlay grafts benefited from superior vascularization and mechanical protection due to their placement within the osteotomized host bone, resulting in fewer complications and better preservation of augmented volume. By contrast, onlay grafts showed higher rates of resorption, flap dehiscence, and graft exposure, particularly in vertical augmentations where soft tissue tension and limited vascular supply are significant challenges. Despite promising findings, heterogeneity among studies and limited long-term data restrict definitive conclusions. Further well-designed randomized controlled trials with standardized protocols and extended follow-up are needed to strengthen the evidence base. Overall, the inlay technique appears to offer predictable and stable outcomes, particularly in complex augmentation scenarios.

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