Histomorphometrical analysis of bone formed in human maxillary sinus floor elevations grafted with OP‐1 device, demineralized bone matrix or autogenous bone. Comparison with non‐grafted sites in a series of case reports.

Abstract

Bone morphogenetic proteins have proven to be effective bone inductors in animals and are therefore promising as inductors of bone formation in humans. In the present study we investigated the tissue formed after grafting osteogenic protein 1 on a collagen carrier (OP-1-device) in the human sinus floor elevation procedure. Three patients were grafted with OP-1 device. For comparison 3 groups of 3 patients were included in the study receiving respectively, autogenous bone, human freeze-dried demineralized bone matrix (DBM) or no graft. This last group had a sufficient alveolar bone height for dental implantation. Six months after grafting, at the time of implantation, biopsies were taken from the grafted area and/or the future dental positions. Undecalcified sections were used for histological and histomorphometrical analysis. All grafted sinuses showed an increased osteoid percentage when compared to non-grafted sinuses. Autogenous bone grafts all showed lamellar bone formation. In the DBM grafts mostly woven bone had been formed, predominantly by what appeared to be osteo-conduction. The OP-1 device gave rise to bone formation in 2 of the 3 patients. After 6 months implants could only be placed in 1 out of the 3 patients treated with OP-1 device. This patient showed mature lamellar bone formation, comparable to autogenous bone grafts. In the second patient all bone found was woven and the presence of a high osteoid percentage and large osteocyte lacunae indicated that this was recently-formed bone. Remnants of the collagen carrier were rare and new bone was never found against them, suggesting that this bone was formed by osteo-induction. In the third patient no new bone had been formed. The device had been encapsulated with fibrous tissue and inflammatory reaction was present. We conclude that in the human sinus floor elevation OP-1 has potential bone inductive capacity, but that results in the 3 patients tested with the current OP-1 device are inconsistent.

Bone morphogenetic proteins in human bone regeneration

“…They observed excessive bone formation outside the original fibular bone contour, suggesting that the dose of rhOP-1 could be reduced. However, when the same dose of rhOP-1 on the same carrier was implanted in the human maxillary sinus, excessive bone formation was not observed (3). These data suggest that the presence of muscle tissue provides favorable conditions for bone induction and that the concentration of BMP can be reduced in such an environment.…”

“…The maxillary sinus is an area surrounded by atrophic maxillary bone and buccal mucosa, but muscle tissue is absent, and the conditions in this anatomical environment are possibly more critical for bone induction. Indeed, at this site, grafting of the same rhOP-1 carrier induced little or no bone in two of three patients treated (3).…”

“…Addition of BMP to a carrier affects the resorption rate of the carrier. An enhanced resorption rate of PLA and DBM carriers in the presence of BMP has been observed in several studies (3,105,164).…”

Maxillary sinus grafting

“…The third patient had bilateral maxillary sinus augmentation, histologically similar to normal bone and successful implant integration. 88,89 BMP-2 in an ACS carrier has been evaluated in a phase 2 and a phase 3 trial for augmentation of the sinus in preparation for dental implants, as well as for extraction site grafting. [90][91][92] The phase 2 trial established that the dosage necessary for sinus augmentation was 12.5 mg of BMP per sinus.…”

Maxillary Sinus Floor Lifting Using Freeze-Dried Homologous Bone And Tibia Autologous Bone: Report On Radiographic And Histological Results

“…19,[66][67][68] El uso de este tipo de materiales se ha documentado ampliamente, con diferentes grados de éxito.…”