Microstructured BCP granules as bone graft substitute in maxillary sinus floor augmentation with two-stage implant placement

Loss of teeth and molars is generally followed by resorption of the alveolar
bone. Severe alveolar bone resorption is often a major obstacle for dental
implant insertion for replacement of molars. In order to regain sufficient bone
quantity and quality for the installation of oral implants in the posterior
maxilla, the sinus floor augmentation procedure can be performed. In this
procedure, access to maxillary sinus is gained through the lateral wall of the
alveolar ridge. Subsequently the sinus floor is augmented by lifting the sinus
mucosa and placing graft material within the created space on the sinus floor.
The use of autogenous bone in sinus floor augmentations is the golden standard.
However, the surgical removal of autologous bone requires an additional
surgical site and comes with a distinct set of potential complications,
including chronic pain of the donor site. Calcium phosphate ceramics (CaP) have
been developed as synthetic bone graft substitutes that eliminate the need for
autogenous bone harvesting. MagnetOs is a novel biphasic CaP developed by Kuros
Biosciences that due to an instructive microstructured surface has
osteoinductive capacity and can induce de novo bone formation. Therefore,
MagnetOs granules may form a very suitable alternative to autogenous bone graft
for the sinus floor augmentation procedure.

The primary objective is to determine the efficacy of MagnetOs BCP granules in
inducing adequate bone quantity and quality to support endosseous dental
implants in the two-staged maxillary sinus floor augmentation procedure. Herein
the treatment will be compared to sinus floor augmentation with autologous bone
graft.

Secondary objective is to assess the clinical performance, functional
performance (of dental implants) and pain with the use of MagnetOs BCP granules
in sinus augmentation as compared to treatment with autologous bone graft.

This is a prospective clinical study to evaluate efficacy of MagnetOs BCP
granules in sinus floor augmentation. The study is designed as a controlled
open- label, randomized, non-inferiority trial.

Patients will undergo sinus floor augmentation with MagnetOs BCP granules as
bone graft substitute or with autologous bone graft. A biopsy will be obtained
from the maxilla before implant placement.

The burden is that all subjects will have to undergo additional examinations
during the regular follow-up visits. The extra examinations will include the
taking of a biopsy at 5 months, measurements of implant stability at 5 months
and 11 months post-surgery and a CBCT scan at 17 months post-surgery.
The potential risks related to this study are associated with normal sinus
augmentation surgery such as pain, infection and failure of osseointegration of
dental implants. Although safety and efficacy have been determined through
pre-clinical animal studies (biocompatibility, safety, efficacy), risk analyses
and clinical evaluations based on literature and high similarity with existing
calcium phosphate bone void filler products, safety and efficacy have not yet
been shown in a clinical study. Although MagnetOs is already available on the
EU market, the current study will be the first study to evaluate MagnetOs in
human subjects and therefore the study will bear a moderate risk.
The direct benefit for the participating subjects is that micro-structured BCP
granules are a bone graft substitute and therefore no autogenous bone will have
to be harvested for the sinus augmentation procedure. This removes the
disadvantages of bone graft procedures from the treatment, including a
secondary operation site and the risk of donor site morbidities like chronic
pain and neurological complications. For some patients that will undergo an
additional procedure in the maxilla that requires autogenous bone, a smaller
amount of bone will be harvested when MagnetOs is used in the sinus.