[Powdered eggshell in the repair of cystic cavities of the jaw. Preliminary study].

This paper is a clinical report on the use of eggshell as a bone substitute in oral surgery. Five volunteers who presented with a cystic cavity of the jaw with a mean size of 2 x 1 cm, were enrolled in the study. After enucleation of the cyst, the cavity was packed with eggshell powder. The results were assessed by clinical examination and repeated radiological examination at 2, 4, and 6 weeks. Two operative sites were checked at 2 months for histological examination. Clinically, the eggshell implants were very well tolerated. In 3 out of 5 patients, a progressive opacification of the cavities with a centripetal ossification occurred within 6 weeks. In one patient, a generalized resorption was noticed. Histological examination confirmed that eggshell powder was not osteoinductive, but it enhanced the bone regeneration from the margins. In conclusions, eggshell powder is a worth-while bone substitute because it is a safe and easily available material. However, only a modest beneficial effect can be expected on bone regeneration.