How to treat ailing and failing implants.

This article describes treatment of the ailing implant (bone loss with pocketing but static at the maintenance checks) and the failing implant (bone loss with pocketing, bleeding upon probing, purulence, and evidence of continuing bone loss irrespective of therapy). Because the surface of the implant is contaminated with endotoxin, it must be detoxified before any regenerative therapy. Studies have shown that citric acid is effective in detoxifying the hydroxyapatite-coated surfaces while tetracycline is more effective in sterilizing the metallic substrate fixtures. Guided tissue regeneration is useful as a "barrier" to prevent exfoliation of the grafted material. Both nonresorbable and resorbable materials have been used with great success. Allografts (freeze-dried bone) and alloplasts (synthetic materials) may be used to achieve a sulcus of decreased depth and possibly some type of osseous regeneration. The author recommends the use of the allograft if the surface is completely detoxified and the alloplast if it is not certain that the surface is sterilized and free of endotoxin. The allograft, being resorbable, will not effect biologic healing against a contaminated surface; hence, the use of the alloplast to "fill" the defect and prevent epithelial invagination.