The main question addressed by this review produced by the Cochrane Oral Health Group was whether or not treatment for moderate to severe gum disease (periodontitis) also has an effect on the prevention or management of heart and blood vessel (cardiovascular) disease.
Gum disease (periodontitis) is a common chronic or persisting condition that can get worse over time. It involves inflammation of the gums, which surround and support the teeth, causing swollen and painful gums and in severe cases loss of the bone (alveolar) that supports the teeth.
Clinical investigations have shown that there might be a link or association between chronic, ongoing gum disease (periodontitis) and heart and blood vessel disease (cardiovascular disease). Some investigators believe that the treatment for gum disease, which gets rid of bacteria and infection and controls inflammation, might prevent the occurrence or recurrence of heart disease.
The evidence on which this review is based was from a search of the clinical data on 7 April 2014. The included randomised controlled study involved 303 participants.
At present there is only one suitable study looking at this issue. The study had problems with its design. Based on this evidence it was not possible to determine whether or not treatment for gum (periodontal) disease has any effect on the occurrence or recurrence of heart disease in people with chronic gum disease.
Quality of the evidence
The quality of the evidence was very low as there was only one study with problems in its design and how the study was conducted.
We found very low quality evidence that was insufficient to support or refute whether periodontal therapy can prevent the recurrence of CVD in the long term in patients with chronic periodontitis. No evidence on primary prevention was found.
There is an association between chronic periodontitis and cardiovascular disease (CVD). However, it is not known whether periodontal therapy could prevent or manage CVD in patients with chronic periodontitis.
The objective of this systematic review was to investigate the effects of periodontal therapy in preventing the occurrence of, and management or recurrence of, CVD in patients with chronic periodontitis.
The electronic databases that were searched were the Cochrane Oral Health Group's Trials Register (to 7 April 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 3), MEDLINE via OVID (1946 to 7 April 2014), EMBASE via OVID (1980 to 7 April 2014), CINAHL via EBSCO (1937 to 7 April 2014), OpenGrey (to 7 April 2014), the Chinese BioMedical Literature Database (1978 to April 2014), the China National Knowledge Infrastructure (1994 to April 2014) and the VIP database (1989 to April 2014). We searched the US National Institutes of Health Trials Register, the World Health Organization (WHO) Clinical Trials Registry Platform and Sciencepaper Online for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.
Randomised controlled trials (RCTs) and quasi-RCTs were considered eligible. Studies were selected if they included patients with a diagnosis of chronic periodontitis and previous CVD (secondary prevention studies) or no CVD (primary prevention studies); patients in the intervention group received active periodontal therapy compared to maintenance therapy, no periodontal treatment or another kind of periodontal treatment in the control group.
Two review authors carried out the study identification, data extraction and risk of bias assessment independently and in duplicate. Any discrepancies between the two authors were resolved by discussion or with a third review author. A formal pilot-tested data extraction form was adopted for the data extraction, and the Cochrane Collaboration's tool for risk of bias assessment was used for the critical appraisal of the literature.
No studies were identified that assessed primary prevention of CVD in people with periodontitis. One study involving 303 participants with ≥ 50% blockage of one coronary artery or a coronary event within three years, but not the three months prior, was included. The study was at high risk of bias due to deviation from the protocol treatment allocation and lack of follow-up data. The trial compared scaling and root planing (SRP) with community care for a follow-up period of six to 25 months. No data on deaths (all-cause or CVD-related) were reported. There was insufficient evidence to determine the effect of SRP and community care in reducing the risk of CVD recurrence in patients with chronic periodontitis (risk ratio (RR) 0.72; 95% confidence interval (CI) 0.23 to 2.22; very low quality evidence). The effects of SRP compared with community care on high-sensitivity C-reactive protein (hs-CRP) (mean difference (MD) 0.62; -1.45 to 2.69), the number of patients with high hs-CRP (RR 0.77; 95% CI 0.32 to 1.85) and adverse events (RR 9.06; 95% CI 0.49 to 166.82) were also not statistically significant. The study did not assess modifiable cardiovascular risk factors, other blood test results, heart function parameters or revascularisation procedures.