Histologic Evaluation of Human Biopsies After Dental Augmentation With a Demineralized Bone Matrix Putty

Histologic Evaluation of Human Biopsies After Dental Augmentation With a Demineralized Bone Matrix Putty
December 2003
Babbush, Charles A. DDS, MScD
Implant Dentistry: Volume 12(4) December 2003 pp 325-332
Lippincott Williams & Wilkins
Private Practice, Lyndhurst, Ohio; and Clinical Professor and Director of Implant Research, Case Western Reserve University, School of Dentistry, Cleveland, Ohio.
Reprint requests and correspondence to:
Charles A. Babbush, DDS, MScD
Brainard Place
29001 Cedar Road
Suite 103
Lyndhurst, OH 44124
Phone: (440) 995-5500
Fax: (440) 995-9955
E-mail: cab@thedentalimplantcenter.net
Abstract
To solve some of the problems inherent in bone regeneration, various types of graft materials, matrix, putty, and gel delivery systems have been developed. These deliver demineralized bone matrix (DBM) to a graft site and maintain it in an appropriate position to achieve favorable results. This prospective study reviewed 10 cases of extraction immediate grafting with a putty-DBM delivery system. Five patients were male and 5 female. At intervals ranging from 4 to 21 months postextraction grafting, bone cores were harvested at the time of surgical insertion of Replace endosteal two-stage implants. All patients were restored with single-tooth self-standing prostheses. Bone quality and quantity in each of the bone cores were evaluated. All 10 cases were completed with favorable outcomes.
Bone-grafting techniques and materials are commonly used to fill defects and voids to restore form and function where bone is missing. Different types of graft materials accomplish this in different ways. Osteoinductive grafts contain bone morphogenetic proteins that can stimulate bone growth through the differentiation of cells into osteoblasts. Osteoconductive grafts provide a scaffold for bone regeneration on or within the surface of the graft material. Graft materials also can be osteogenic by containing cells capable of forming bone, and/or osteopromotive by containing proteins such as human transforming growth factor beta (TGF-B) and human platelet-derived growth factor (PDGF) that are indirectly involved in the bone healing cascade. 1-4
Graft materials are generally classified into 3 groups. Bone taken from a donor site in the patient to be grafted at another site is known as autografts. Allografts refer to bone harvested from another person (living or deceased) and then processed. Bone grafts composed of a wide variety of synthetic materials fall into the alloplast category.
Although autografts have traditionally been considered the gold standard of bone-grafting materials, donor-site morbidity and the invasive nature of harvesting at a second site have somewhat limited their use in oral and maxillofacial surgery. A popular alternative to autografts has been demineralized bone matrix (DBM) used in particulate form. DBM is cadaveric bone that has been processed to remove the mineral component, leaving a scaffold of collagen and various growth-factor proteins that have been shown to induce bone formation. 5
Problems with handling and containing DBM particles have limited the exclusive use of this material. Maintenance of the graft material within the defect site is of paramount importance. Any migration of particles from the area could compromise the graft success because of inadequate regeneration of the defect and potential ectopic bone formation. In oral and maxillofacial surgery, membranes have often been used to retain the graft material at the defect site. However, the use of membranes increases both the technical difficulty and cost of the grafting procedure. 6 To address this problem, DBM graft materials have been developed that use a carrier to keep the particles together at the graft site. 7
Materials such as glycerol, polymers, polymeric gels, and collagen have all been used successfully to maintain graft containment. 8-10 Of these materials, polymeric gels offer unique clinical properties. Polymers are versatile long-chain molecules with variable material characteristics. Polymers vary in physical state from solids to liquids to gels. One such DBM carrier, poloxamer 407, used in some of the DynaGraft¨? allograft materials (GenSci Orthobiologics, Irvine, CA), exhibits a unique reverse-thermal behavior. It exists as a liquid at cold temperatures and a firm gel at body temperature.
This atypical behavior of poloxamer 407 offers an advantage in DBM placement and containment. When placing a poloxamer/DBM graft in either putty or gel form at the defect site, the material becomes firmer as it warms to body temperature. The polymer component is completely biocompatible and resorbed within 3 to 5 days postimplantation. 4,8,11,12 The DBM at the defect site promotes rapid bone formation and is completely resorbed within 4 to 6 months. 7
In oral surgery, DynaGraft¨? Putty has been used successfully to treat a variety of bony defects. 9,13,14 In this study, patients undergoing restorative surgery for placement of dental implants were treated with DynaGraft¨? Putty after extraction of a tooth. The healing response was later histologically quantified using core biopsies obtained at the time of dental implant placement.
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