Periodontally compromised vs. periodontally healthy patients and dental implants: A systematic review and meta-analysis

Abstract

Objectives

To test the null hypothesis of no difference in the implant failure rates, postoperative infection, and marginal bone loss for the insertion of dental implants in periodontally compromised patients (PCPs) compared to the insertion in periodontally healthy patients (PHPs), against the alternative hypothesis of a difference.

Methods

An electronic search without time or language restrictions was undertaken in March 2014. Eligibility criteria included clinical human studies, either randomized or not.

Results

2768 studies were identified in the search strategy and 22 studies were included. The estimates of relative effect were expressed in risk ratio (RR) and mean difference (MD) in millimetres. All studies were judged to be at high risk of bias, none were randomized. A total of 10,927 dental implants were inserted in PCPs (587 failures; 5.37%), and 5881 implants in PHPs (226 failures; 3.84%). The difference between the patients significantly affected the implant failure rates (RR 1.78, 95% CI 1.50–2.11; P < 0.00001), also observed when only the controlled clinical trials were pooled (RR 1.97, 95% CI 1.38–2.80; P = 0.0002). There were significant effects of dental implants inserted in PCPs on the occurrence of postoperative infections (RR 3.24, 95% CI 1.69–6.21; P = 0.0004) and in marginal bone loss (MD 0.60, 95% CI 0.33–0.87; P < 0.0001) when compared to PHPs.

Conclusions

The present study suggests that an increased susceptibility for periodontitis may also 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.

Clinical Significance

There is some evidence that patients treated for periodontitis may experience more implant loss and complications around implants including higher bone loss and peri-implantitis than non-periodontitis patients. As the philosophies of treatment may alter over time, a periodic review of the different concepts is necessary to refine techniques and eliminate unnecessary procedures. This would form a basis for optimum treatment.

Introduction

In an attempt to decrease implant failure rates, more attention is being placed on understanding the etiologic and risk factors that lead to the failure of dental implants.¹ The question if patients with a history of periodontitis are more at risk for peri-implant disease has received increasing attention in the last years.² There is some evidence that patients treated for periodontitis may experience more implant loss and complications around implants including higher bone loss and peri-implantitis than non-periodontitis patients.³ A history of treated periodontitis does not seem to adversely affect implant survival rates over short times of follow-up.⁴ A small number of periodontal maintenance patients seem to be refractory to treatment and go on to experience continued and significant tooth loss. These subjects also have a high level of implant complications and failure.⁵ However, the finding that titanium implants are but foreign bodies have resulted in a general questioning whether periodontitis and peri-implantitis are at all related forms of disease.⁶

Some clinicians assume that periodontally compromised patients (PCPs) present a potentially higher risk for implant failure than healthy individuals. The reason for this assumption is that a similar pathological bacterial flora forms around diseased teeth and diseased implants, though with some differences in partially and completely edentulous patients.⁷ Implants are rapidly colonized by indigenous periodontal pathogens in partially dentate patients harbouring periodontal lesions.⁷ Moreover, long-term outcomes demonstrated that implants in non-smoking PCPs previously treated for periodontitis were more prone to developing marginal bone loss compared with those in PHPs.⁸ These results were obtained despite the fact that all patients were regularly enrolled in and were compliant with a supporting periodontal therapy (SPT) programme over 10 years.⁸ Fardal and Linden⁵ observed that smoking, stress and a family history of periodontal disease were identified as factors associated with a refractory outcome, and these variables remained significant after multivariate analysis. Another study showed that marginal bone level at 10 years was significantly associated with smoking, implant location, full-mouth probing attachment levels, and change, over time, in full-mouth probing pocket depths.⁹ Having said this, a recent investigation demonstrated significantly different mRNA signatures between periodontitis and peri-implantitis.¹⁰

Therefore, a pertinent question in relation to implant therapy in patients susceptible to periodontitis is whether these patients may also show an elevated risk for peri-implant tissue destruction. Thus, the aim of this meta-analysis is to compare the survival rate of dental implants, postoperative infection, and marginal bone loss of dental implants inserted in PCPs and in periodontally healthy patients (PHPs). The present study presents a more detailed analysis of the influence of periodontal disease on the implant failure rates, previously assessed in a published systematic review.¹