STIMULATION OF EARLY BONE-FORMATION BY THE COMBINATION OF AN OSTEOPROMOTIVE MEMBRANE TECHNIQUE AND HYPERBARIC-OXYGEN

Large bone defects often heal incompletely as a result of ingrowth of connective tissue. By using a mechanical hindrance, a porous expanded polytetrafluoroethylene (e-PTFE) membrane, it is possible to prevent f ibroblasts and other soft connective tissue cells from entering the de fect, thereby allowing osteogenesis to occur unhindered. As evidenced in several investigations, this osteopromotive membrane technique caus es a strongly improved bone regeneration of well defined osseous lesio ns. Hyperbaric oxygen treatment has also been shown to accelerate bone healing. In this study the value of combining the two techniques was investigated. Through-and-through bone defects, 5 mm in diameter, were produced unilaterally in the angular region of the mandibles of adult rats (n = 60); the defects in half the number of animals were covered lingually and buccally with membranes. The animals were then divided into four groups: treatment with membrane alone, treatment with hyperb aric oxygen alone, combined treatment, and no treatment. Histological examination of the defects after 14 days showed that the combination o f techniques had resulted in significant improvement in bone healing, compared with hyperbaric oxygen or the membrane technique alone. Syner gistic effects can thus be achieved by the use of membranes and stimul atory factors for bone regeneration.