Interventions for replacing missing teeth: antibiotics at dental implant placement to prevent complications

Some dental implant failures may be due to bacterial contamination at implant insertion. Infections around biomaterials are difficult to treat, and almost all infected implants have to be removed. In general, antibiotic prophylaxis in surgery is only indicated for patients at risk of infectious endocarditis; with reduced host-response; when surgery is performed in infected sites; in cases of extensive and prolonged surgical interventions; and when large foreign materials are implanted. A variety of prophylactic systemic antibiotic regimens have been suggested to minimise infections after dental implant placement. More recent protocols recommended short-term prophylaxis, if antibiotics have to be used. Adverse events may occur with the administration of antibiotics, and can range from diarrhoea to life-threatening allergic reactions. Another major concern associated with the widespread use of antibiotics is the selection of antibiotic-resistant bacteria. The use of prophylactic antibiotics in implant dentistry is controversial.

To assess the beneficial or harmful effects of systemic prophylactic antibiotics at dental implant placement versus no antibiotic or placebo administration and, if antibiotics are beneficial, to determine which type, dosage and duration is the most effective.

We searched the Cochrane Oral Health Group's Trials Register (to 17 June 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 5), MEDLINE via OVID (1946 to 17 June 2013) and EMBASE via OVID (1980 to 17 June 2013). There were no language or date restrictions placed on the searches of the electronic databases.

Randomised controlled clinical trials (RCTs) with a follow-up of at least three months, that compared the administration of various prophylactic antibiotic regimens versus no antibiotics to people undergoing dental implant placement. Outcome measures included prosthesis failures, implant failures, postoperative infections and adverse events (gastrointestinal, hypersensitivity, etc).

Screening of eligible studies, assessment of the risk of bias of the trials and data extraction were conducted in duplicate and independently by two review authors. Results were expressed as risk ratios (RRs) using a random-effects model for dichotomous outcomes with 95% confidence intervals (CIs). Heterogeneity, including both clinical and methodological factors, was to be investigated.

Six RCTs with 1162 participants were included: three trials compared 2 g of preoperative amoxicillin versus placebo (927 participants), one compared 3 g of preoperative amoxicillin versus placebo (55 participants), one compared 1 g of preoperative amoxicillin plus 500 mg four times a day for two days versus no antibiotics (80 participants), and one compared four groups: (1) 2 g of preoperative amoxicillin; (2) 2 g of preoperative amoxicillin plus 1 g twice a day for seven days; (3) 1 g of postoperative amoxicillin twice a day for seven days, and (4) no antibiotics (100 participants). The overall body of evidence was considered to be of moderate quality. The meta-analyses of the six trials showed a statistically significant higher number of participants experiencing implant failures in the group not receiving antibiotics (RR 0.33; 95% CI 0.16 to 0.67, P value 0.002, heterogeneity: Tau(2) 0.00; Chi(2) 2.87, df = 5 (P value 0.57); I(2) 0%). The number needed to treat for one additional beneficial outcome (NNTB) to prevent one person having an implant failure is 25 (95% CI 14 to 100), based on an implant failure rate of 6% in participants not receiving antibiotics. There was borderline statistical significance for prosthesis failures (RR 0.44; 95% CI 0.19 to 1.00), with no statistically significant differences for infections (RR 0.69; 95% CI 0.36 to 1.35), or adverse events (RR 1; 95% CI 0.06 to 15.85) (only two minor adverse events were recorded, one in the placebo group). No conclusive information can be derived from the only trial that compared three different durations of antibiotic prophylaxis since no event (implant/prosthesis failures, infections or adverse events) occurred in any of the 25 participants included in each study group. There were no trials that evaluated different antibiotics or different antibiotic dosages.

Scientific evidence suggests that, in general, antibiotics are beneficial for reducing failure of dental implants placed in ordinary conditions. Specifically 2 g or 3 g of amoxicillin given orally, as a single administration, one hour preoperatively significantly reduces failure of dental implants. No significant adverse events were reported. It might be sensible to suggest the use of a single dose of 2 g prophylactic amoxicillin prior to dental implant placement. It is still unknown whether postoperative antibiotics are beneficial, and which antibiotic is the most effective.