In vivo evaluation of resorbable bone graft substitutes in beagles: histological properties

Calcium phosphate cement (CPC) is a promising material for use in minimally invasive surgery for bone defect repairs due to its bone-like apatitic final setting product, biocompatibility, bioactivity, self-setting characteristics, low setting temperature, adequate stiffness, and easy shaping into complicated geometrics. However, even though CPC is stable in vivo, the resorption rate of this bone cement is very slow and its long setting time poses difficulties for clinical use. Calcium sulfate dehydrate (CSD) has been used as a filler material and/or as a replacement for cancellous bone grafts due to its biocompatibility. However, it is resorbed too quickly to be optimal for bone regeneration. This study examines the invivo response of a hydroxyapatite (HA), [apatitic phase (AP)]/calcium sulfate (CSD) composite using different ratios in the mandibular premolar sockets of beagles. The HA (AP)/CSD composite materials were prepared in the ratios of 30/70, 50/50, and 70/30 and then implanted into the mandibular premolar sockets for terms of 5 and 10 weeks. The control socket was left empty. The study shows better new bone morphology and more new bone area in the histological and the histomorphometric study of the HA (AP)/CSD in the 50/50 ratio.

In vivo evaluation of resorbable bone graft substitutes in mandibular sockets of the beagle

Hydroxyapatite (Ca(10)(PO(4))(6)(OH)(2)), with its high biocompatibility and good bioaffinity, stimulates osteoconduction and is slowly replaced by the host bone after implantation. However, clinical use of HA as a bone substitute has proved problematic. It is difficult to prevent dispersion of the HA granules and to mold the granules into the desired shape. Calcium sulfate as a bone graft substitute is rapidly resorbed in vivo releasing calcium ions, but fails to provide a long-term, three-dimensional framework to support osteoconduction. The setting properties of calcium sulfate, however, allow it to be applied in a slurry form, making it easier to handle and apply in different situations. This study examines the in vivo response of a (Hydroxyapatite, apatitic phase)/calcium sulfate dehydrate (CSD) composite using different ratios in the mandibular premolar sockets of the beagle. The HA (AP)/CSD composite materials prepared in ratios of 30/70, 50/50, and 70/30 were implanted into the mandibular premolar sockets for 5 and 10 weeks. The control socket was empty. The authors compared the radiographic properties and the changes in height and width of the mandibular premolar sockets in the beagle. The composite graft in the 30/70 ratio had the best ability to form new bones.