The lower phylogenetic level of the animals compared to humans was the main limitation of the present study. An increased number of animals might allow reaching a statistical difference in favor of the treated sites also in the antrostomy region. Nevertheless, the outcomes obtained, allow to performing studies in humans that might demonstrate the advantages of applying autologous bone on the antrostomy.

Some features of autologous bone grafts may be relevant to the resorption process such as its form (block or particulate) [23], its microarchitecture (cortical or cancellous) [24], or the embryogenesis of the donor sites (intramembranous or endochondral ossification) [25].

The present study harvested autologous bone from the rabbit tibia, i.e., endochondral ossification. In humans, this type of ossification has demonstrated less dimensional stability than intraoral grafts that present intramembranous ossification [24, 25]. For this reason, and because of the less patient morbidity and risk of complications, intraoral autogenous bone harvesting is routinely used [26, 27]. Intraoral particulated bone (intramembranous origin) can be obtained from the cortical bone of the lateral window [28] or from neighbor intraoral areas (e.g., from the ramus, or the chin, or retromolar area). The difference in the origin of the autograft should be taken into consideration when interpreting the results of the present preclinical study.

It can be concluded that the placement of autogenous bone in the antrostomy and the subjacent region after maxillary sinus elevation, provides slightly better new bone formation compared with sites only grafted with xenograft. Though, only the subjacent close-to window region showed a statistical significance within treated sites at 8 weeks of healing. Despite the limitations of the present study and due to its preclinical nature, results should be extrapolated to humans with caution.