Introduction

The use of dental implants for the treatment of edentulism is a routine procedure that has shown favorable outcomes in a variety of clinical situations [1–3]. However, certain factors increase the complexity of this treatment, such as limited availability of the bone required for proper implant placement [3, 4]. When considering these clinical scenarios, rehabilitations in the posterior maxilla deserve special attention, as this region is particularly prone to insufficient bone volume due to the reduction in alveolar ridge height following tooth extraction and the concomitant pneumatization of the maxillary sinus [5, 6]. Consequently, techniques for maxillary sinus floor elevation combined with the use of bone substitute biomaterials have been efficiently applied to overcome this limitation [7, 8].

Among bone substitute biomaterials, the autogenous bone graft is considered the gold standard [6, 9], as it is the only material that exhibits all three biological properties of bone formation—osteoconduction, osteoinduction, and osteogenesis [5]. However, due to several clinical limitations associated with its use, such as the limited amount of graft material available, donor site morbidity, and high resorption rates [5, 6], synthetic biomaterials have been proposed as alternative materials for maxillary sinus floor elevation procedures [7]. It has been reported that despite the favorable biological properties of autogenous bone grafts, osteoconductive bone substitutes have shown promising clinical outcomes and represent a viable alternative to the use of autogenous grafts [10].

Beta-tricalcium phosphate (β-TCP) is a synthetic biomaterial with osteoconductive properties that has been widely used as a bone substitute and shown favorable clinical outcomes in maxillary sinus floor elevation procedures [5, 6]. However, the absence of osteoinductive and osteogenic properties in bone substitute materials is associated with limitations in the promotion of the bone healing process [11]. Therefore, several strategies have been investigated to enhance the biological potential of osteoconductive grafts [12–18]. Clinical studies that combined bone substitutes with growth factors such as recombinant human bone morphogenetic protein-2 (rhBMP-2) [19] and recombinant human growth and differentiation factor-5 (rhGDF-5) [14] demonstrated increased bone formation; however, the therapeutic application of these growth factors remains costly [20]. An alternative approach to improving the biological properties of osteoconductive grafts, which has shown promising results, is the combination of these biomaterials with autogenous bone [13, 15, 16, 21]. Nevertheless, to date, the combination of autogenous bone and β-TCP in maxillary sinus floor elevation procedures has only been minimally explored.

Therefore, the aim of the current study was to compare bone healing in maxillary sinuses grafted with β-tricalcium phosphate (β-TCP), associated or not with autogenous bone graft, in maxillary sinus floor elevation procedures. The null hypothesis of this study was that the addition of autogenous bone graft would not influence bone repair in maxillary sinuses grafted with β-TCP.