CLINICAL Is implant placement a risk in patients with increased susceptibility to periodontitis? Johan Hartshorne 1 A critical appraisal of a systematic review: Chrcanovic BR, Albrektsson T, Wennerberg A, Periodontally compromised versus periodontally healthy patients and dental implants: a systematic review and meta-analysis, Journal of Dentistry (2014), http://dx.doi.org/10.1016/j.jdent.2014.09.013 Article accepted: 25-9-2014 (Origin of research – University of Malmö, Sweden) Summary Systematic review conclusion: The present study suggests that an increased susceptibility for periodontitis may translate to an increased susceptibility for implant loss, loss of supporting bone, and postoperative infection. The results should be interpreted with caution due to the presence of uncontrolled confounding factors in the included studies, none of them randomized. Critical appraisal conclusion: Periodontally compromised patients are at higher risk post-operative infection, marginal bone loss (peri-implant disease) and implant failures in comparison to periodontally healthy patients. The clinical significance and implications of the results of this review should be interpreted with caution due to lack of controlling important confounding factors such as smoking habits that is known to influence the incidence of post-operative infections, peri-implant disease and implant failures. Implications for clinical practice: It is clinically prudent to accept that patients with a history of chronic periodontitis (susceptible or compromised) are at greater risk for implant related complications and failures. Patients with chronic periodontitis should be assessed and managed on an individual basis when contemplating implant therapy. The risks are higher in patients with aggressive periodontitis or with co-morbidity factors such as smoking or uncontrolled systemic conditions such as diabetes and immune- deficiency and therefore need extra precautionary measures. Appropriate periodontal therapy, adherence to a strict periodontal maintenance program and limiting co- morbidity risk factors are critical for ensuring a predictable and successful treatment outcome with implant therapy. 1 Johan Hartshorne B.Sc., Clinical question B.Ch.D., M.Ch.D, M.P.A. Ph.D. In periodontally compromised patients (PCP’s) receiving dental implants, do post- (Stell), FFPH.RCP (UK), operative infection, marginal bone loss and implant failure rates differ compared to Visiting Professor, Department of implants inserted in periodontally healthy patients (PHP’s). Periodontics and Oral Medicine, University of Pretoria, Pretoria, Review methods South Africa. Methodology This study followed the PRISMA Statement guidelines. 1 The methodological quality E-mail: assessment of the studies was executed according to the Newcastle-Ottawa scale [email protected] (NOS). 2 32 INTERNATIONAL DENTISTRY – AFRICAN EDITION VOL. 5, NO. 2 CLINICAL Search strategy and study selection was automatically omitted from the meta-analysis. A funnel The investigators did an electronic search without time or plot was used to estimate publication bias and other biases language restrictions in March 2014 of the electronic related to sample size. The choice between fixed-effect and databases: PubMed, Web of Science, and the Cochrane Oral random effects model was based on I 2 statistical test for Health Group Trials Register, to identify papers on the topic in heterogeneity. the clinical question. They also conducted a manual search of dental implant-related journals. The reference list of the identified Main results studies and the relevant reviews on the subject were also A total of 22 publications were included in the meta-analysis. scanned for possible studies. Online databases Ten studies were controlled clinical trials (CCTs) and twelve (www.clinicaltrials.gov; www.centerwatch.com/clinicaltrials; retrospective analyses. There were no randomized controlled www.clinicalconnection.com) were also checked for possible studies. All studies except one were rated as having high clinical trials in progress. Three reviewers independently methodological rigor however, all were judged to be at high screened the titles and abstracts identified through the electronic risk of bias. The funnel plot showed asymmetry when the searches for articles related to the focus question. Full text articles studies reporting the outcome ‘implant failure’ in the of studies appearing to meet the inclusion criteria, or where there comparison between PCPs vs. PHPs are analyzed, indicating were insufficient data in the title and abstract to make a clear possible presence of publication bias. From the 22 studies decision were obtained and read by all the reviewers. comparing PHPs and PCPs, a total of 10927 dental implants Disagreements were resolved by discussion between the authors. were inserted in PCPs, with 587 failures (5.37%), and 5881 implants were inserted in PHPs, with 226 failures (3.84%). Eligibility and exclusion criteria A statistically significant increase in implant failure rates Only randomised controlled trials (RCTs) or controlled clinical was observed with insertion of dental implants in PCP’s trials on humans were eligible for this study. The clinical compared to PHPs. Pooling of the data showed a RR of 1.78 studies had to compare implant failure rates in PCP’s (95% CI 1.50-2.11) (P <0.00001). When only the CCTs receiving dental implants compared to PHP’s. Implant failure were pooled, a RR of 1.97 resulted (95% CI 1.38 -2.80) was defined as the complete loss of the implant. Case also showing a similar statistically significant increase in reports, technical reports, animal studies, in vitro studies, and implant failure rates in PCPs. (P = 0.0002). reviews papers were excluded from this study. Only four studies provided information about postoperative infection. The insertion of dental implants in PCPs or PHPs Outcome measures and data extraction and synthesis statistically affected the incidence of postoperative infections Implant failure, postoperative infection and marginal bone in favor of PHPs. A RR of 3.24 (95% CI 1.69-6.21) loss were the primary outcomes that were measured. The (P=0.0004) was observed. estimates of relative effect for implant failure and Five studies provided information on the marginal bone postoperative infection were expressed in risk ratio (RR) with loss in PCPs and PHPs receiving dental implants (A total of a 95% confidence interval (CI). The estimate of relative effect 212 implants were placed in PCPs and 269 implants in for marginal bone loss was expressed as mean difference PHPs) There was statistically significant difference in marginal (MD) in millimeters with a 95% confidence interval (CI). The bone loss (MD 0.60, 95% CI 0.33-0.87; P < 0.0001) data for each variable was used to construct a Forest plot between PCPs and PHPs, favoring PHPs. for analysis of the pooled data. The authors of primary studies were contacted to obtain Conclusion information on missing data. Whenever outcomes of interest The present study suggests that an increased susceptibility for were not clearly stated, the data were not used for analysis. periodontitis may also translate to an increased susceptibility The statistical unit for the outcomes was the implant. for postoperative infection, loss of supporting bone, and Appropriate statistical analysis was conducted to implant loss. However, the results should be interpreted with determine biases, heterogeneity and differences in outcome caution due to the presence of uncontrolled confounding measures between PHPs and PCPs. factors in the included studies. A meta-analysis was only performed on studies with similar comparisons reporting the same outcome measures. Studies The authors did not declare whether they received lacking information about the relative probability of an event financial support or whether there was any potential VOL. 5, NO. 2 INTERNATIONAL DENTISTRY – AFRICAN EDITION 33 HARTSHORNE conflict of interest with respect to the authorship and/or limitation was the varying lengths of follow-up time (3-5 publication of this review. years) (median of 5 years). Such relative short follow-up could possibly have led to an underestimation of the estimate Commentary of the failure rate. Background and importance Wide inclusion criteria generally increase the risk of Dental implant therapy has become a well-established finding heterogeneity, thus making the analysis and treatment modality with favorable long-term success rates for interpretation of confounding factors on results difficult. replacing missing teeth in the general population. With However, statistical analysis surprisingly showed no increasing numbers of patients receiving dental implants, it significant heterogeneity between the test and control group. is certain that post-operative complications, incidence of peri- Based on the statistical test the investigators choose to use implant disease and implant failures will increase, posing a the fixed-effect model. However, it should be pointed out that significant health care problem for both the patient and the the choice between using a fixed-effect and a random-effects clinician. It is also plausible that more patients will receive meta-analysis should never be made on the basis of a implants to replace missing teeth lost due to periodontal statistical test for heterogeneity. 7 The two models are not the disease. In an attempt to limit post-operative complications, same and conceptually measure different things. The peri-implant