Background: Dental implant failures have a multifactorial background; dependency within patient/jaw exists. Failures caused by bone loss are rare. Lately, advanced bone loss around implants has been discussed.
Purposes: Our aim was to study advanced bone level changes (>or=2 mm) regarding "clustering effect," prediction, and dependency. Further, we also aimed to study if the number of radiographs/radiographic examinations could be reduced.
Materials and methods: Six hundred and forty patients (3,462 Brånemark implants) with radiographic follow-ups >or=5 years were included, whereas patients with overdentures and augmentation procedures were excluded.
Results: Progression rate for implants with advanced bone loss was largest during the first year; thereafter, slow. A cluster effect was found with more advanced bone loss in few patients. Position was important for lower jaw implants with larger bone loss for implants placed close to midline. Age, jaw type, and implant placement were identified as predictors. The longer the follow-ups, the more bone loss around a randomly selected and examined implant, and the more implants per patient, the higher the risk for bone loss >or=2 mm around any other implant. Still, it seems safe to exclude radiographic follow-ups during the first 5 years. Dependency within the patient was found, hence the "one-implant-per-patient technique" can be applied.
Conclusion: The number of intraoral radiographs per examination and, more importantly, radiographic examinations can be reduced without jeopardizing good clinical management, a statement valid even for Brånemark implants with advanced bone loss.