And the controversy will likely continue for some time, as there is still relatively little consensus about the best strategies to prevent biofilm formation.
Marco Esposito, D.D.S., Ph.D., a professor in the department of oral and maxillofacial surgery at the University of Manchester School of Dentistry in the U.K., led the Cochrane analysis (Cochrane Database of Systematic Reviews, July 7, 2010). He and three others searched the Cochrane Oral Health Group's Trial Register, the Cochrane Central Register of Controlled Trials, Medline, and Embase for randomized, controlled human trials on implant failure following presurgical antibiotic prophylaxis published in any language up to June 2010.
Virtually the same team, led by Dr. Esposito, had published an earlier Cochrane review in 2008, including two trials, that showed a statistically significant 78% reduction in risk of experiencing implant failure when receiving antibiotics (European Journal of Oral Implantology, Summer 2008, Vol. 1:2, pp. 95-103).
“Every drug has risks and costs for patients and the healthcare system associated
— Parish Sedghizadeh, D.D.S., M.S.,
University of Southern California
In the new meta-analysis, four studies met all the search criteria and were analyzed by Dr. Esposito and his colleagues. The first two were included in the earlier meta-analysis. One of these compared the use of 1 g of amoxicillin given one hour preoperatively plus 500 mg of amoxicillin given four times a day for two days to no antibiotic treatment (Journal of Clinical Periodontology, January 2008, Vol. 35:1, pp. 58-63). Patients undergoing bone-augmentation procedures concurrently with implant placement were included. No statistically significant differences were observed for any of the outcome measures. The second, led by Dr. Esposito, compared 2 g of amoxicillin given one hour preoperatively to placebo (European Journal of Oral Implantology, Spring 2008, Vol. 1:1, pp. 23-31). Patients undergoing bone-augmentation procedures concurrently with implant placement were not included. Again, no significant outcome differences were observed.
The third trial also compared 2 g of amoxicillin given one hour preoperatively to placebo (Journal of Oral Implantology, Winter 2009, Vol. 2:4, pp. 283-292). No significant differences were observed in any of the outcome measures. The fourth trial was led by Dr. Esposito, used the same conditions as his 2008 study, and was published after the 2010 Cochrane meta-analysis (European Journal of Oral Implantology, Summer 2010, Vol. 3:2, pp. 135-143). Again, no significant outcome differences were observed.
When the studies were aggregated by the meta-analysis team -- for a total of 1,007 patients -- statistical analyses indicated no significant heterogeneity among the studies. The results also showed patients who received antibiotics had a statistically significant 60% reduction in risk of implant failure (95% confidence interval 0.19-0.84). The team calculated that 33 patients needed to be treated with antibiotics to prevent them from having an implant failure.
Dr. Esposito and his colleagues concluded, as they did in their 2008 study and meta-analysis, that routinely administering prophylactic antibiotics is advisable for patients undergoing routine procedures for placement of dental implants.
Henny van der Mei, Ph.D., a professor at the University Medical Center Groningen who has published papers on the formation of biofilm on dental materials, including implants (for example, Journal of Dental Research, July 2010, Vol. 89:7, pp. 657-665), agrees with the recommendation by Dr. Esposito's team. Biofilms are widely believed to be the chief culprit for implant failure, but whether this is due to biofilm formation at the time of implantation or in the following months has not been conclusively determined, she noted.
"I am in favor of a prophylactic boost of antibiotics," van der Mei told DrBicuspid.com. "I know that a lot of people are afraid of bacterial resistance against antibiotics and so on, but one boost normally does not cause any resistance. With respect to the other side effects, I can deal with these side effects, while infections related to implants are very difficult to treat, and, as a result, very often the implant needs to be removed."
However, Parish Sedghizadeh, D.D.S., M.S., director of the University of Southern California Center for Biofilms at the Herman Ostrow School of Dentistry, believes the current evidence does not support routine preimplant antibiotic prophylaxis.
"It would be easy for me to say that we should just use antibiotics in surgery to 'cover our ass,' as they say. I can't say that, however, because the evidence in my opinion doesn't support it, and because every drug has risks and costs for patients and the healthcare system associated with it," Dr. Sedghizadeh told DrBicuspid.com. "Many of us argue against routine prophylaxis because of the potential for the development of resistant strains of organisms. Such resistant strains can result in serious or life-threatening infections."
He believes more discussion and investigation are needed to determine which patients are suitable for receiving antibiotics before implant surgery, "particularly since the success rate for dental implants is very high to begin with." He suggests that perhaps those at high risk of failure are appropriate for such prophylaxis.
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