The relationship between periodontitis and peri-implantitis remains a matter of debate. The question posed is one that I am asked nearly daily as a periodontist but to date has no clearly defined answer. Similar to most questions asked regarding the relationship between periodontitis and various systemic diseases, the evidence aimed at addressing this question is conflicting.
In 2001, Quirynen et al. hypothesized that ongoing periodontitis was not directly correlated to increased risk of peri-implantitis. Specifically, Quirynen et al. (2001) found the mean marginal bone and clinical attachment loss around teeth during a 5-year observation period was 0.48 mm and 0.65 mm, respectively. The mean marginal bone loss around implants during the same interval was 0.09 mm; thus there is a huge difference apparent in bone loss around teeth and implants in patients with chronic periodontitis. In this study, the patient who showed the greatest amount of bone loss over the experimental period showed 0.99 mm of bone loss around the affected tooth but only 0.19 mm of bone loss around the implant. In this study, none of the periodontal parameters evaluated had a significant implant on the prediction of marginal bone loss around dental implants. Thus, Quirynen et al. (2001) concluded that patients with a history of arrested, or even progressive periodontitis that undergo implant therapy do not demonstrate any more marginal bone loss around implants than patients with a healthy periodontium.
Conversely, in a meta-analysis Salfi et al. (2009) concluded that a moderate level of evidence indicates that patients with chronic periodontitis are at a significantly greater risk for implant failure and greater marginal bone loss compared to periodontally healthy subjects. (The odds ratio for implant failure in periodontitis patients was found to be 3.02.) A random effects model showed an average of 0.6 mm of more marginal bone loss in peridontitis patients versus healthy controls. Thus, Salfi et al. (2009) concluded that patients with periodonitits were more than 3 times more likely to have implant failure than periodontally health patients. However, one must ask how relevant is a difference of 0.6 mm in the long-term? If the bone loss does not progress, a loss of < 1 mm is unlikely to increase risk of implant failure (however may cause issues of peri-mucositis). On the contrary, if progressive, the effects may be catastrophic. For example, if these patients continued to loose 0.6 mm of bone around their implants each year, in 10 years the majority of implants would have 50% bone loss and in 20 years the implants would be lost.
Karoussis et al. (2003) completed a 10-year implant maintenance protocol on patients who replaced teeth lost due to chronic periodontitis versus other reasons (i.e. trauma, caries, etc.) and found more biological complications in the periodontitis patient group. Specifically, when this study arbitrarily assigned the clinical parameters of probing depth ≤ 5 mm and no bleeding on probing the success rates were at 71.4% and 94.5% in the periodontitis versus non-periodontitis groups, respectively. When a threshold was set at probing depth ≤ 6 mm and no bleeding on probing, these proportions were elevated to 81% and 96.7%, respectively. The implant survival rate for the group with a past history of chronic periodontitis was 90.5%, while for the group with no past history of periodontitis it was 96.5%.
These studies illustrate the ongoing debate addressing the question, “Does periodontitis affect implant survival and peri-implant bone loss?” It seems plausible that periodontally health patients may have greater implant success than patients with either arrested or active periodontitis; several theories to answer this question have been postulated. One theory proposes that seeding of bacteria from a periodontally involved site to a peri-implant crevice may occur while another proposes that the pre-existing altered host response in patients with periodontitis may translate to immunologic problems with proper healing around dental implants. To date, neither theory is well founded in the literature.
Given the conflicting data addressing this question, I advise my patients that there is potential for an increased risk of implant failure due to a history of periodontitis, yet the evidence to date is blurry and does not fully elucidate such a relationship. Additionally, I discuss with them several more important factors related to implant success, which are under their control, such as not smoking and good oral hygiene. I always reassure my periodontitis patients that we place implants in patients with a history of periodontitis daily and, given that the disease has been arrested and the patient is committed to good long term maintenance, continue to see success in implant therapy. Thus, in my opinion, as long as the patient does not have active periodontal disease or inflammation, implants are not contradicted in this population and continue to be the treatment option of choice in many situations.