When treating patientsundergoing antiresorptive therapy special care has to be taken to avoid thedevelopment of bisphosphonate-associated osteonecrosis of the jaws (BPONJ/BRONJ).It may be caused by on going osteoporosis, multiple myeloma or malignantdiseases with metastases to the bone.
Furthermore concomitant disease, systemicfactors and triggering factors such as periodontal diseases, extractions ordenture sores could cause BRONJ (70). Osteonecrosis usually occursin elderly patients (69 years ± 10 years) due to its relation to primarydisease (71). Studies showed thatimplantation in patients undergoing oral BIS therapy <5 years is regarded asa safe procedure and furthermore they did not influence the short term implantsurvival rate (1-4 years) (72).
However other articlesstates that bisphosphonate treatment during implantation accelerated thedevelopment of BRONJ and it occurs less frequently when antiresorptive therapywas done prior to implantation (73). Several studies had beenperformed to investigate the frequency of BRONJ in todays clinical dentalpractice and they uniformly came to the conclusion that success rate of dentalimplants in patients treated with BIS drugs ranges between 95 % – 99,6 % in thetotal number of studies and none of these patients developed BRONJ and allimplants expressed similar profiles, even those in a control group with nonmedicated patients (32, 37,74). According to the AmericanDental Association (ADA) BIS treatment is not considered as a contraindicationfor the short-term success of a dental implant, however long term studiesinvolving larger clinical cases are needed to discover performance of implantsplaced in BIS medicated patients compared to non medicated patients (75). But the risk for developing BRONJ is higherin patients undergoing intravenous bisphosphonate therapy because theconcentration is higher within the body. Therefore a complete medical historyand route of administration should be assessed before any intervention (76). Another important factor forthe prevention of BRONJ is antimicrobial and antibiotic prophylaxis. It isnecessary that the patient receive antibiotic prophylaxis before any opensurgical intervention to decrease the active bacterial cell count within thebody and therefore exclude any infection of the wound or the surgical site suchas infective endocarditits and bacteraemia in patients with artificialprosthesis within the body. In antibiotic prophylaxis penicillin remains thefirst choice, but in case of a penicillin allergy, metronidazole may be given (77).
It is administered usuallyprior to the treatment, but dependent on the severity of the case, also aftertreatment. However the use of antibiotics is not uniformly well adapted andsometimes considered controversial. According to a report in 2007 from theAmerican Heart Association (AHA) antibiotic prophylaxis should be limited forpatients categorized into a high-risk group.
The national institute of healthand excellence in the United Kingdom however does not recommend antibioticprophylaxis at all (78). The strategies in preventionof BRONJ include the following principles (79): Explanation of the risk of BRONJ and the need for effective oral hygiene. Dental examination and x-rays before the start of treatment. Surgical, conservative and prosthetic treatments prior to antiresorptive treatment. Relining of poorly fitting dentures and examination of pressure sores. Extractions only where absolutely necessary in combination with antibiotic prophylaxis regimen and plastic wound closure. Antibiotic prophylaxis before, during and after surgical interventions.
Every 6 months dental check up and professional dental cleaning. Cessation of smoking and treating systemic disorders such as Diabetes Mellitus. Re-evaluate the indication for antiresorptive treatment. Generally implantation is not a contraindication inpatients with osteoporosis if the adequate bone volume and distribution isassessed before implant therapy, however studies suggest that the impaired bonemetabolism around implants in osteoporotic patients may lead to inadequateosseointegration (80). Osteoporosis alters the processof osseointegration in trabecular bone, which results in significant lessbone-implant contact.
But the success of the implantation depends largely onthe health of the recipient patient. Patients with poor oral health have lesschances of implant survival than those who are completely healthy or show a lowrisk. The stages to deal with before implant surgery are the same as they wouldbe in a patient without osteoporosis. A vital factor is the oral hygiene of thepatient and although the risk of ONJ in patients treated against osteoporosisis very low, they have to be properly informed about the actual low risk andhave to sign an informed consent before starting the treatment (81)