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Dental Medicine and Oral Health Sciences

Unfinished endodontic treatment and the presence of apical infections may increase the risk of CVD

Clinical Question: Does root canal therapy affect the risk of cardiovascular disease in the general population compared to no dental intervention?

Clinical Bottom Line: There is limited evidence suggesting a potential association between completed RCT and CVD. The evidence suggests that the risk for CVD is related to an increase in the number of teeth with unfinished root canal therapies (RCTs). Overall the results are statistically significant, clinically meaningful, however not consistently precise. The quality of the evidence is compromised by a lack of studies with a rigorous methodology, presence of selection and assessment bias. In addition, due to the lack of adequate control groups, more prospective cohort studies with more robust methodology would help improve the validity of the results. As such, the results need to be interpreted with caution. There is a lack of applicability of the results given that both study populations are non-diversified (only of white participants or only Taiwanese individuals).

Evidence search:
("Root Canal Therapy"[Mesh] OR "Endodontics"[Mesh] OR "endodontics"[tiab] or "root canal"[tiab]) AND ("Cardiovascular Diseases"[Mesh] OR “cardiovascular disease”[tiab] OR “cardiovascular”[tiab]) AND ("retrospective studies"[Mesh] OR "cross-sectional studies"[Mesh] OR "observational study"[pt])

Search date: October 28, 2019 - additional search: The Journal of Evidence-Based Dental Practice (1 article); TRIP database (1 article).

 

Author, year Source of evidence Population Characteristics Methods

1. Gomes et al. (2016)
PMC: 26011008

Retrospective cohort study

Population: a convenience sample of North-American white adults, mean age 55 years old (range of 22-89 years old)

Sample size, total:  N=278, 48.6% female

 

Exposure: root canal therapy, root canal therapy associated with apical periodontitis (collectively described as endodontic burden).

Primary outcome:  incidence of cardiovascular events (CVEs) including myocardial infarction, cardiovascular death, or angina.

Follow-up: 17.4 years (mean), maximum of 44 years  

Measurements: radiographs, medical questionnaires, clinical evaluations, medical records

 

Key Results

22.3% of the participants with apical periodontitis and RCT developed CVEs independently from any confounding variables. RR (CVEs, endodontic burden of 3 or more teeth) = 1.77 (95% CI 1.04, 3.02); RR (CVEs, endodontic burden 1 or 2 teeth) = 0.99 (95% CI 0.61, 1.60.).

Evidence Quality

Individuals with an endodontic burden of 3 or more teeth had 1.77 times the risk of CVE compared to those who had an endodontic burden of 1/2 teeth; RD = 6% (95% CI 0.3%, 16%). The results are statistically significant, clinically meaningful (5% threshold), but not clinically decisive.

Strengths: The exposure was measured validly and reliably by two different examiners with a satisfactory inter-examiner agreement; the examiner was blinded to the medical data of the patients.

Limitations: Missing a control group with no endodontic burden is a clear limitation. Also, the disease and the treatment were combined to predict CVD, which made it difficult to determine whether the disease process or the treatment itself contributed the most to the risk ratio for CVD. Finally, access to the dental records of the participants at baseline only limited the inclusion of any incidence of AP or RCT throughout the follow-up period and could not be related to the incidence of CVE (potential assessment bias).

 

Author, year Source of evidence Population Characteristics Methods

2. Lin et al. (2015)
PMC: 26472681

Retrospective cohort study

A randomly selected sample of Taiwanese population (47% were between the ages 20-40 years old; 41% were 40-60 years old, and 12% over 60 years old)

Sample size: N = 283, 590; 56% female

Exposure: root canal therapy (RCT)

Primary Outcome: cardio-vascular diseases (CVD)

Follow-up (mean): 6 years (until the first diagnosis of CVD hospitalization for acute MI, Ischemic Stroke or CAD)

Measurement: periapical radiographs (unfinished RCTs were RCT was started but without a completion code)

Data analysis: Cox multivariate regression analysis

 

Key Results

The overall incidence rate of CVD was 0.21% per person/year for a single unfinished root canal, 0.28% for two unfinished RCTs, and 0.58% for three unfinished RCTs.
HR for completed RCTs = 0.86; 95% CI, 0.85–0.88); HR for three unfinished RCTs = 3.61 (95% CI 2.36 – 5.51; HR for one or two unfinished RCTs = 1.22 (95% CI 1.11, 1.35).

Evidence Comments

More than three unfinished root canals is associated with a 3.61 higher risk of future CVD hospitalization compared to the control group with no unfinished RCT; RD = 21% (CI 95% 11%, 36%). The results are statistically significant, clinically meaningful (5% threshold, 8% CVD prevalence), and clinically decisive.

One or two unfinished root canals are associated with 1.22 higher risk to CVD hospitalizations compared to the control group (RD = 1.76% (95% CI 0.88%, 2.80%)).
The results are statistically significant and clinically decisive, but not clinically meaningful (5% threshold, 8% CVD prevalence).
 
Strengths: the outcome of this study was measured in a valid and reliable way using the International Classification of Diseases system created by the WHO (ICD-9); the Cox multivariate regression analysis were used to adjust for confounding factors that may affect the incidence of CVD.

Limitations: It is unclear if the exposure was properly measured since endodontic therapy was measured only at the starting point and at the endpoint of the root canal treatment and categorized as completed RCT or not. Thus, information about the quality of the obturation, apical and coronal seal or potential missed canals, etc. was not disclosed. It is unclear whether the participants were free of the outcome at the beginning of the study, this creates a potential source of selection bias; the absence of a control group (subjects without root canal treatment) is a clear limitation.

Applicability

A homogenous population was recruited in both studies (i.e., White North-American adults or Taiwanese adults), which may affect the generalizability of the results to the Canadian population. The applicability is also compromised by the lack of clinical precision of the results, thus calling for studies with more rigorous methodology. Although both studies have done well in controlling for potential confounders, one of the critical risk factors to include are genetics; this confounder may potentially have been controlled for through having a homogeneous population.  They also reinforce the importance of endodontic treatment quality and motivating practitioners to find new ways to improve their treatment. Overall, the results showed that unfinished or poor-quality root canal therapies are associated with an increased risk of cardiovascular disease. They also illustrated that persistent infection (apical periodontitis) is associated with an increased risk of cardiovascular disease, much like periodontitis. Both studies used a seemingly adequate follow up period to witness the outcome. The results found may be used to educate patients on the importance of treating infected teeth.  At the same time the results can be used as a message to dental practitioners to be diligent when performing endodontic treatment: to take time to properly disinfect and seal the root canal with adequate restorative choices. Even though the results are clinically meaningful, they are not clinically decisive in which the risks of CVS do not outweigh the RCT benefits.

Authors: Christina Angelopoulos, Stamatis Kouniaris, Abigail Edery, Dipo Ajayi (DMD3 students)

Faculty mentors:  Dr. Faleh Tamimi, Dr. Svetlana Tikhonova, Doaa Taqi

Acknowledgments: Martin Morris (McGill librarian)

Date: April 1, 2020

 

 

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