Bisphosphonates

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What hygienists need to know

by Carol Tekavec, CDA, RDH

Bisphosphonates are a class of drugs used to treat various systemic problems, chiefly osteoporosis and tumors associated with certain types of cancer. Thousands of men and women take the drugs, which can be administered orally or intravenously.

According to the American Dental Association Council on Scientific Affairs Expert Panel Report, published in the Journal of the American Dental Association in August 2006, bisphosphonates work by inhibiting osteoclast activity. An osteoclast is a bone cell that removes bone tissue and induces bone cell death. Suppressing bone cell death promotes an increase in bone mass.

Therefore, the drugs are recommended for the treatment of osteoporosis in women after menopause and for men suffering from thinning of the bone. They may also be used to treat Paget's disease, thinning of bones caused by steroid treatment, and bone problems associated with cancer.

Possible problems

Bone mass is maintained by a balance between bone cell destruction and bone cell generation (osteoblast activity). When the balance is changed due to the suppression of osteoclasts, it appears that normal bone repair may be impacted. The Journal of Oral and Maxillofacial Surgery (2005) reported that “bisphosphonate-associated osteonecrosis of the jaw occurs mainly in the oral cavity because the jaws have a greater blood supply than other bones and a faster turnover rate, resulting in a high concentration of bisphosphonates.”

In other words, bisphosphonates can keep bone “strong,” but in some individuals the imbalance between normal creation and normal destruction of bone cells can result in infection and in osteonecrosis of the jaw. The jaw appears to be a focal point because of a natural occurrence of high bone cell turnover.

Apparently, the osteonecrosis can occur spontaneously or as the result of dental treatment.

Oral bisphosphonates include, but are not limited to, Actonel, Boniva, Didronel, Fosamax, and Skelid. Intraveous bisphosphonates include, but are not limited to, Aredia, Bonefos, Boniva IV, Reclast, and Zometa.

What does BON look like?

The lesions associated with bisphosphonate associated osteonecrosis (BON) are described as “ragged, oral mucosal ulcerations that expose underlying bone and often are extremely painful. The lesions are persistent and do not respond to conventional treatment modalities such as debridement or antibiotic therapy.”

The American Association of Oral and Maxillofacial Surgeons (AAOMS) describes BON as “exposed, necrotic bone, which persists for more than eight weeks in a patient who is taking, or has taken, a bisphosphonate and has not had radiation therapy to the head and neck.” (Source: Dental Management of Patients Receiving Oral Bisphosphonate Therapy — Expert Panel Recommendations, ADA.org)

Patients may have swelling, infection, loosening of teeth, drainage, and exposed bone. These symptoms may occur spontaneously in the bone, but are more common at the site of a tooth extraction. The symptoms of BON do not resolve with routine dental or periodontal treatment.

According to the AAOMS, patients who have taken intravenous bisphosphonates are more likely to develop BON than those who receive only oral medications. Prolonged use of bisphosphonates (longer than two years), smoking, over 65 years of age, and diabetes have been associated with an increased risk for BON. Local risk factors include extractions, implant placement, periapical surgery, and periodontal surgery with osseous injury.

Dental management of patients

According to the AAOMS, patients should have an oral exam, and any unsalvageable teeth should be removed prior to taking the drugs. Any invasive dental procedures should be completed, and optimal periodontal health should be achieved.

If a patient is already taking bisphosphonates, the following should be considered:

Routine dental treatment does not need to be modified if the only issue is the use of bisphosphonates.
Oral bisphosphonates can result in BON, but the risk is much lower than with IV bisphosphonates.
The risk for developing BON may be minimized but not eliminated.
Discontinuing bisphosphonate therapy does not eliminate all risk for BON.
The possibility of multifocal involvement should be avoided. A person who needs full-mouth periodontal surgery might be well served to have one sextant of surgery accomplished to see how he/she heals before receiving full-mouth treatment.
Patients should have their questions addressed. A consent form with the patient's written acknowledgement is recommended. (A single sheet informed consent form for bisphosphonate therapy and dental treatment is included in my treatment-specific informed consent booklet. Look at the booklet at www.steppingstonestosuccess.com.)

Implant placement should be considered only after a careful assessment of the literature and specific patient risk factors. A few experts are indicating that implants may be contraindicated, particularly if the patient has received IV bisphosphonates.

Extractions and other types of oral surgery should be avoided.
Endodontic treatment is preferable to surgery.

According to Dr. Robert E. Marx, author of a book on bisphosphonate therapy and BON, a Serum CTX blood test (serum C-terminal telopeptide test) and NTX test (urinary N telopeptide of type I collagen) can be performed to measure the risk of BON. He asserts that the higher the levels of these markers, the more active the bone turnover is, therefore the less likelihood is for BON. His further contention is that if a patient has been taking oral bisphosphonates for less than three years, the risk is low. If a patient has been taking IV bisphosphonates for any amount of time or oral doses for longer than three years, the risk is much higher. His suggestion is to have patients discontinue bisphosphonates for four months prior to any treatment and four months after treatment. Dr. Marx also says that implants are not recommended for bisphosphonate users. Any already in place should be observed for problems.

The ADA report makes no such recommendations, including the validity and/or value of a “bisphosphonate drug holiday,” but states that further objective research needs to be done.

Periodontal considerations

According to the ADA report, bisphosphonate users with periodontal disease should receive nonsurgical therapy whenever possible. This has implications for hygienists.

Patients with periodontal disease who take bisphosphonates may be appropriate candidates for periodontal scaling and root planing. (D4341)
Treating patients in a quadrant or sextant approach may be helpful. This way the reaction of the bone and tissue to the procedures can be evaluated before treating the entire mouth.
Patients whose disease process does not resolve may be treated with surgery, with an eye on the least invasive process.
There appears to be no evidence that patients who receive an adult prophy (D1110) or a debridement (D4355) have an increased risk of BON.
“In-office” chlorhexidine gentle irrigation or patient home use appears to be of value for patients at risk for BON.
Patients need to receive detailed information as well as a written informed consent form to read and sign prior to treatment.

The final word on BON is yet to be heard. It appears that any person who has taken bisphosphonates may be at increased risk for osteonecrosis. As clinical hygienists, this has important implications for patients and ourselves. Written informed consent and detailed progress notes are essential.