Introduction

Dental implants have become a predictable treatment option for replacing missing teeth because they provide improved stability, function, and patient comfort compared with conventional removable prostheses [1]. Their long-term success depends largely on osseointegration, which is influenced by implant material, implant surface characteristics, implant design, host bone quality, surgical technique, and loading conditions [2]. Among these factors, bone quality and quantity are particularly important because adequate bone volume allows proper implant positioning, while bone density contributes to mechanical engagement and primary stability [3].

The posterior maxilla remains one of the most challenging regions for implant placement. This region commonly presents with low-density trabecular bone, reduced ridge dimensions following tooth loss, and maxillary sinus pneumatization [4]. D3 and D4 bone types are frequently encountered in this area and are associated with reduced mechanical resistance during implant insertion [3]. As a result, achieving adequate primary stability may be difficult, especially when conventional subtractive drilling techniques are used.

Conventional implant osteotomy preparation removes bone to create space for the implant fixture. Although this method is effective in dense bone, it may be less favorable in low-density bone because removal of additional trabecular bone can further reduce the mechanical support surrounding the implant bed [5]. Various alternative techniques, including undersized drilling, osteotome condensation, ridge expansion, and guided bone regeneration, have been used to improve implant placement in compromised ridges. However, these methods may be associated with additional surgical trauma, increased patient discomfort, risk of cortical plate fracture, higher treatment cost, or longer healing time [6].

Osseodensification was introduced as a non-subtractive implant site preparation technique designed to preserve and compact bone during osteotomy preparation [7]. This technique uses specially designed densifying burs in a counterclockwise mode under copious irrigation. The burs compact autogenous bone particles along the osteotomy walls, thereby increasing local trabecular density and improving the mechanical environment for implant placement [7]. Lahens et al. reported that osseodensification improved biomechanical fixation and histologic bone response around endosteal implants in low-density bone [8]. Koutouzis et al. demonstrated that osseodensification-mediated plastic deformation can produce measurable ridge expansion and allow simultaneous implant placement [9]. Salman and Bede also reported ridge expansion with osseodensification in narrow alveolar ridges without dehiscence or fenestration [10].

Although previous studies have evaluated osseodensification in relation to implant stability, bone density, and ridge expansion, limited clinical evidence is available regarding its combined effect on peri-implant bone density and alveolar ridge width specifically in the D3 and D4 bone of the posterior maxilla. Furthermore, many studies have assessed ridge changes at limited points, whereas evaluating crestal, mid-apical, and apical levels may provide a more complete understanding of dimensional changes around the implant site. Therefore, the present study was conducted to evaluate the effect of osseodensification on ridge expansion and peri-implant bone density in the D3 and D4 bone types of the posterior maxilla using cone-beam computed tomography (CBCT). We hypothesized that osseodensification would result in significant increases in alveolar ridge width and peri-implant bone density following implant placement.