Clinical, Radiographic and Histologic Assessment of a New Xenograft Enhanced With Hydrogel in Augmentation of the Maxillary Sinus: A Randomized Controlled Trial

Severe atrophy of the posterior maxilla is challenging when implant supported restorations are needed. This occurs with advanced bone loss following long standing extractions along with maxillary sinus pneumatisation leading to inadequate bone height to receive a dental implant. A variety of approaches of whether to use short implants, augment the defective site along with placing an implant or even a staged approach where the atrophic site is augmented as a primary stage followed by implant placement as a secondary stage -in cases of severe atrophy- are suggested. Different techniques, as well as materials, have been proposed for augmentation of the atrophic bone to receive an endosseous implant. To date, they are both subject to continuous modifications.

Aim is to assess a novel hydrogel-enhanced xenograft material; clinically, radiographically and histologically in lateral window maxillary sinus floor elevation in a staged augmentation approach. Null hypothesis suggests that there is no significant difference between using hydrogel-enhanced xenograft material in comparison with graftless augmentation of the maxillary sinus floor in terms of tissue reaction, formed bone quantity and quality. Whereas, the alternative hypothesis claims favourability of the hydrogel-enhanced xenograft over graftless augmentation of the maxillary sinus floor.

Thirty posterior maxillary edentulous sites requiring open sinus augmentation for staged dental implant placement will be studied. Patients will be randomly allocated into two groups. Group 1 (study group) will receive a xenograft enhanced with hydrogel after Shneiderian membrane elevation. Group 2 (control group) will have stainless steel screws/pins placed buccopalatally to maintain the elevated membrane and stabilize the formed blood clot as graftless augmentation. Surgeries will be evaluated clinically in terms of pain, edema and tissue response during the follow up period. Radiographic assessment will be performed during the surgical follow-up period and after 8 months; to evaluate the formed bone height and density using CBCT. After 8 months a cylindrical bone core using a trephine bur will be taken from the augmented site, this osteotomy will be further prepared to receive the implant. Bone cores from both groups will be examined histologically.