Cementum, pulp, periodontal ligament, and bone response after direct injury with orthodontic anchorage screws: a histomorphologic study in an animal model.

PURPOSE: To assess the histologic response of the periodontium, cementum, and pulp after intentional root injury with titanium screws. MATERIALS AND METHODS: Three female beagle dogs were used, and a total of 60 self-drilling/self-tapping miniscrews were manually inserted into the maxilla and the mandible with the intention of placement in close proximity or in direct contact with the roots. Digital radiographs were taken to select the sites with root injuries. After a 3-month period, the animals were killed and serial nondecalcified histologic sections were obtained with the miniscrew in place. RESULTS: Sixteen sites with significant root injury were identified. Four sites presented with cementum abrasion, 7 sites had dentin penetration up to 50% of the diameter of the screw, and 5 sites had miniscrew penetration into the pulp space with root fragmentation. At all damaged sites, continuous cementum repair could be observed. There was no evidence of external resorption or pulpal necrosis and/or inflammatory infiltrate. Point ankylosis was seen only in cases of severe injury with root fragmentation. Finally, woven bone was present along the miniscrew threads. CONCLUSION: When titanium screws penetrate root cementum or dentin, pulpal necrosis and/or inflammation was not observed at 12 weeks in an animal model. Cementum regenerates at every injury site, but ankylosis can occur with root fragmentation. Woven bone is present at the screw-bone interface even with root contact suggesting osteointegration.

Bisphosphonate use and health history questionnaire.

The health history form is a rapid, time-honored method used by practitioners to assess a patient's medical history before treatment. Because of increased reports of bisphosphonate-related osteonecrosis of the jaws (BRONJ), we investigated the percentage of our patients taking oral bisphosphonates who actually reported taking the medication on our health history form. A questionnaire inquiring about bisphosphonate use was sent to 1,400 female patients who had undergone implant placement in the last five years. A total of 500 responses were received; of these, 112 reported they used bisphosphonates. We then reviewed the charts of the 112 patients to determine the percentage of patients who had included bisphosphonate use in their health history form. Only 35% of our patients who were using bisphosphonates had reported taking bisphosphonates on the health history form. With the difficulties in treating BRONJ, we strongly suggest including direct questions concerning bisphosphonate use in the medical history form so practitioners can identify the patient population that is at risk and can modify the treatment plan to avoid potentially disastrous clinical situations.