Osteonecrosis associated with dental implants in patients undergoing bisphosphonate treatment.
, , , , , . Osteonecrosis associated with dental implants in patients undergoing bisphosphonate treatment. Clin. Oral Impl. Res. 00: 2012; 1–9.Abstract
Objectives
Bisphosphonate-related
jaw necrosis (BRONJ) associated with dental implants is a rare but
continuously reported complication. To verify clinical and pathological
characteristics of BRONJ around dental implants, the present study
analyzed clinical, radiographic and histopathological findings of these
lesions.
Patients and methods
Nineteen
patients were diagnosed with osteonecrosis of the jaw associated with
dental implants and treated at our institute from 2008 to 2011. The
patients' medical history, demographic features, radiographic, and
histopathological findings along with information on bisphosphonates
(BP) administration were analyzed.
Results
The
majority of BRONJ patients associated with dental implants used oral BP
for osteoporosis. The patients were divided into two groups: BP
initiation before (n = 16) and after (n = 3) implant surgery. Only three patients (15.8%) could be regarded as “implant surgery-triggered” BRONJ. Many patients (n = 9)
showed successful osteointegration after fixture installation to an
average of 35 months (11–82 months) until the development of
osteonecrosis. The histological features of the lesion showed that the
necrotic bone with empty lacunae was infiltrated by inflammatory cells
and bacterial colonies. Viable osteocytes were also observed in some
areas of the bony specimens. Three types of bone destruction pattern
were observed: (i) complete necrosis of the bone around the implant
(frozen type), (ii) extensive osteolysis around the implant with or
without sequestra (osteolytic type), and (iii) sequestration of bone
with an implant maintaining direct implant–bone contact (en block
sequestration type). These findings could be existed at the same lesions
depending on the degree of local bone destruction and the severity of
the infection.
Conclusion
These
results and those of others suggested that already osseointegrated
dental implants can also cause the osteonecrosis around the implant
after BP administration. En block sequestration of bone with implant
might be one of the characteristics of implant-related BRONJ, which is
different from peri-implantitis-induced bone destruction. The possible
role of microcracks in this type of bone destruction needs to be
examined further.
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