There have been three Cochrane Database System reviews of this controversial subject of prophylactic delivery of antibiotics in advance of dental implant placement: 2003, 2008, and 2010.
Theoretically, since it is known that there is transmission of bacteria from periodontally involved teeth to an implant (Meijndert L, Eur J Oral Sci. 2010; 118(4):357-63) delivery of an antibiotic prior to implant placement could reduce the overall burden of intraoral bacterial and thus increase the survival rate of the implanted prosthesis.
It has been estimated that dental implants have approximately a 90% survival rate up to 15 years. However peri-implantitis, an infection involving the bone surrounding the implant, may be as high as fourteen percent per some estimates (PA Norowski, JD Bumgardner. Biomaterial and antibiotic strategies for peri-implantitis: a review; J Biomed Mater Res B Appl Biomater. 2009 Feb;88(2):530-43) and this condition can lead to implant failure. The bacteria associated with peri-implantitis include fusobacterium ssp, A actinomycetemcomitans, and P gingivalis (also associated with periodontal disease around teeth). Norowski (above) suggests that the first 12 months are critical with respect to development of implantitis.
It is also generally acknowledged that the risk of implant failure increases in patients who smoke, have poor oral health, are diabetic, or when the implant is coated with calcium phosphate or has a roughened surface.
The Journal of Oral and Maxillofacial Surgery published a dental implant supplement in 1997. Two articles in this supplement are pertinent to the discussion of prophylactic antibiotic and dental implant placement. The first article presents data that appears to demonstrate that the use of preoperative antibiotics significantly improves the survival rate of dental implants (Dent C, et al, The influence of preoperative antibiotics on success of endosseous implants up to and including stage II surgery: a study of 2,641 implants. J of Oral and Maxillofac Surg, Vol 55(12):19-24).
The second article suggests that pre-operative rinses with chlorhexidine may also improve the implant survival rate (P Lambert, et al, The influence of 0.12% chlorhexidine digluconate rinses on the incidence of infectious complications and implant success. Vol 55(12):25-30).
In contrast, but only related to post implant placement, S Renvert, AM Roos-Jansaker, & N Claffey in their review of the literature, (Non-surgical treatment of peri-implant mucositis and peri-implantitis: a literature review; J Clin Periodontol. 2008 Sep;35(8 Suppl):305-15) selected 24 reports from 437 studies assessing post-implant placement management and concluded that “ mechanical non-surgical therapy could be effective in the treatment of peri-implant mucositis lesions. Furthermore, the adjunctive use of antimicrobial mouth rinses enhanced the outcome of mechanical therapy of such mucositis lesions. In peri-implantitis lesions, non-surgical therapy was not found to be effective. Adjunctive chlorhexidine application had only limited effects on clinical and microbiological parameters. However, adjunctive local or systemic antibiotics were shown to reduce bleeding on probing and probing depths”
These authors recommend that there be more randomized-controlled studies assessing the various non-surgical treatment models for the management of post implant placement peri-implant mucositis and peri-implantitis.
So pre-implant antibiotic prophylaxis might be beneficial but post implant management with an adjunctive medication known to inhibit bacterial grown may only have a limited effect on treating peri-implantitis. This is what the above literature suggests.
But what about bacterial suppression over time; does it last with initial treatment?
This important question is partially answered by L Meijndert and colleagues from the Department of Oral and Maxillofacial Surgery and Maxillofacial Prosthetics at the University Medical Center Groningen, the Netherlands, who sought to assess the prevalence of seven periodontal marker pathogens before implant placement and 1 year after loading in periodontally healthy individuals. They assessed bacterial threshold levels commonly associated with periodontal disease as the guide to whether a patient should be pretreated (Eur J Oral Sci, 2010, 118(4):357-63).
The authors report that at baseline, 49.5% of the periodontally healthy subjects harbored one or more marker pathogens above threshold levels. Periodontal treatment reduced the pathogen levels below threshold values in 78.3% of these initially colonized subjects, particularly in relation to Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. However after one year the levels of periodontal pathogens were again above threshold levels in 74.1% of all subjects. The authors conclude that given these results, pre-implant reduction in bacteria may be unpredictive with respect to subsequent post implant bacterial levels.
This brings us to the most recent Cochrane report.
In this report published in 2010, authors M Esposito, et al, sought to assess the beneficial or harmful effects of systemic prophylactic antibiotics at dental implant placement versus no antibiotic/placebo administration and, if antibiotics were of benefit, to find which type, dosage and duration was the most effective (Cochrane Database Syst Rev. 2010; July 7;(7):CD004152).
As they mention in their abstract “to minimize infections after dental implant placement various prophylactic systemic antibiotic regimens have been suggested. More recent protocols recommended short term prophylaxis, if antibiotics have to be used. With the administration of antibiotics adverse events may occur, ranging from diarrhea to life-threatening allergic reactions. Another major concern associated with the widespread use of antibiotics is the selection of antibiotic-resistant bacteria”
The Cochrane search strategy typically assesses the Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase. In this case they reviewed studies up until June 2nd, 2010. They also hand searched a number of dental journals and did so in numerous languages. Ultimately they selected randomized controlled clinical trials (RCTs) where there was follow up of at least three months that compared various prophylactic antibiotic regimens in patients to those not receiving antibiotics in advance of implant placement. The outcome measures included prosthesis failures, implant failures, as well as postoperative infections and adverse events.
Ultimately, only four RCTs were identified as having the best quality for review. Three compared patients with two grams of amoxicillin delivered preoperatively to placebo (927 patients) and the other one compared the use of one gram taken pre-implant placement and then 500mg taken four times a day for two days after placement (with a group without antibiotic coverage (80 patients)). Meta-analysis of the four trials revealed that a significantly higher number of patients that experienced implant failure were not pretreated with antibiotic. Only two minor events occurred with antibiotic pre-treatment.
It is concluded from this analysis that there is support for the use of two grams (2) provided orally one hour preoperatively to prevent dental implant failure. However it is also noted that “it is still unknown whether postoperative antibiotics are beneficial, and which one is the most effective antibiotic”
In conclusion, the reader should appreciate that at this time there is no published standard protocol related to the pre-treatment ‘prophylactic’ use of antibiotics prior to implant placement. The choice of antibiotic, dosing regimen, and post-treatment ‘antibacterial’ management is largely left to the discretion of the treating clinician. Evidence based guidance must come from the limited studies that are available including those cited above. Clinicians are left to define what type of post-implant bacterial management they think is reasonable.
For the curious reader, a most interesting discussion on the issue can be found at: http://www.osseonews.com/use-of-antibiotics-for-implant-placement-evidence-based-protocol/.
Submitted by Dr Jeff Burgess, Editor in Chief