Calcium oxalate deposition in the periodontium secondary to chronic renal failure

Deposition of calcium oxalate in the periodontium with accompanying bone loss and tooth resorption, occurred in a 55-year-old woman on long-term renal dialysis for end-stage renal disease. These deposits were birefringent upon examination with polarized light. Scanning electron microscopy of the deposits revealed clusters of sharply angular oblong and needlelike crystals. Microincineration followed by staining with alizarin red S was positive for calcium oxalate. X-ray diffraction studies of the crystals in the tissue specimen revealed a pattern identical to that of commercially prepared calcium oxalate monohydrate. It is postulated that pre-existing inflammatory periodontal disease may have provided the appropriate milieu for the deposition and precipitation of crystals. These deposits, acting as a foreign body, further intensified the inflammatory response, resulting in extensive alveolar bone loss and external tooth resorption.