INTRODUCTION

OAT with warfarin has been widely prescribed for people with thromboembolic diseases ^1,2. Despite the effectiveness of anticoagulants to prevent stroke, heart attack, and other embolic complications, individuals under OAT have an increased risk of bleeding during surgical procedures, including oral procedures ². Whilst there is an extensive literature discussing whether to continue or discontinue OAT in patients undergoing dental surgery and the effectiveness of local measures for bleeding control ^2-4, little is known of the oral health of the population receiving anticoagulants.

With the growth of both life expectancy and the prevalence of cardiovascular diseases ⁵, there is a tendency for the number of individuals who will use anticoagulants to increase. OAT is frequently prescribed for elders who present periodontal disease, dental caries, decreased salivary flow, and reduced host defenses, leading to a range of oral diseases ^2,6. In this manner, we expect that the number of patients under OAT seeking dental care will increase in the following years. This research aimed to describe the burden of oral diseases and the self-reported periodon-tal disease of patients under warfarin.

METHODS

The Research Ethics Committee from Universidade Federal de Minas Gerais (UFMG) approved this cross-sectional study (CAAE 17726219.0.0000.5149).

We recruited outpatients from the Brazilian National Health System attending the anticoagulation clinic ⁷ of the Hospital das Clínicas, UFMG, from October 2019 to March 2020. Although a convenience sample was selected, we highlight that our sample size is acceptable for this study since there is no literature evidence. Eligible patients at the clinic who gave authorization were consecutively recruited.

Eligibility criteria were patients over 18 years old undergoing OAT with warfarin. Exclusion criteria were patients with insufficient medical history information, individuals who could not communicate their answers, or patients with spontaneous bleeding.

Data collection comprised interviews using structured questionnaires and oral examination. First, the examiner was trained and calibrated to diagnose dental caries. Then, a pilot study was conducted with ten patients. The agreement level was observed through Cohen's Kappa coefficient above 0.80.

To measure caries, the DMFT index was used, according to the World Health Organization standards for epidemiological studies ⁸. In addition, the use of prostheses was clinically established ⁸.

Each patient was asked regarding sociodemographic characteristics and self-perception of periodontal disease. The self-reported periodontal disease instrument evaluated risk factors for periodontal disease and self-reported periodontal status ⁹.

Descriptive statistics were performed using SPSS Statistics for Windows, Version 24.0. Armonk, NY: IBM Corp. Central tendency and variability measures were calculated for dental caries severity. Self-reported periodontal disease is presented by frequency and proportion.

RESULTS

The surveyed sample included 158 patients. The mean age was 58.8 (SD = 12.1) years, with a predominance of the female sex (62.7%), and a low educational level (60.8%). The indications for warfarin showed that most patients had some fibrillation (43.4%) or some prosthetic heart valves (65.8%).

The mean INR was 2.63 (SD = 0.83), and the average DMFT index was 22.9 (SD = 7.6;Table 1), with the missing component being the highest. Patients between 59-91 years of age had a higher DMFT index (mean 26.8, SD = 5.2) than those under 58 years old. Moreover, a higher DMFT index was observed in patients who did not floss (mean 27.0, SD = 7.2), or who brushed only once a day (mean 28.0, SD = 6.2).

Table 1 Decayed, Missing, Indicated for extraction and Filled Teeth (DMF-T) index of patients under anticoagulation therapy with warfarin, Belo Horizonte, Brazil, 2019-2020 

Source: the authors

*Minimum wage in Brazil is R$1,100.00 (Real), which is equivalent to US$ 210.00 (American Dollar).

The use of maxillary prosthesis (53.2%) was higher than the mandibular one (32.3%). The total prosthesis was the most common in the maxilla (31.6%). The need for prostheses in both arches was 44,9%, and the need for mandibular prosthesis reached 66.5%. The most common prosthetic rehabilitation need was the combination of fixed and removable prostheses. The percentage of participants that referred gum disease, tooth migration, tooth mobility, and tooth loss due to periodontal diseases were 29.6%, 37.4%, 30.4%, and 10.5%, respectively (Table 2).

DISCUSSION

This study described the oral health of 158 individuals under warfarin. The majority were female, and participant's ages were close to 60 years old. The prevalence of dental caries was high, and severity increased with age and poor oral hygiene.

In our study, the sample presented high DMFT values. Findings have shown that patients under OAT present a higher number of dental surfaces covered with biofilm and a lower number of filled teeth ^6,10. Individuals under OAT, by fear of gingival bleeding, might brush less often, resulting in biofilm deposits what is a risk for caries ^6,11,12. Similarly, a previous study showed that flosser patients had fewer caries and fewer missing teeth ¹³.

Data from the general population in Brazil shows that adults had better DMFT values (16.75; IC 95%: 16.29-17.21)¹⁴ than individuals under OAT from the age group of 27-58 years. Conversely, elders from the general population had worse DMFT (27.53; IC 95%: 27.03-28.04)¹⁴ than individuals using anticoagulants in the group of 59-91 years. The difference in populations and methodologies may explain the discrepancies.

The prevalence of tooth loss in the studied population reflects the abundant demand for oral prostheses. The small provision of this procedure in primary health care contributes to the large observed demand ¹⁵.

On the other hand, although the gold standard for periodontitis diagnosis is still clinical examination ⁹, many warfarin patients have a risk for infective endocarditis, requiring antibiotic prophylaxis before invasive dental procedures. The self-reported periodontal disease instrument has shown good accuracy in identifying non-diseased individuals ⁹.

Only 29.6% acknowledged having gum disease. In Spain, the prevalence of gingival bleeding was 58.3%¹¹. Untreated, periodontal diseases seem a risk factor for the recurrence of thromboembolic events ¹⁶. Then, it is important to develop strategies to improve oral health literacy.

In this study, it is not possible to extrapolate our findings due to the convenience sample. Moreover, we did not have a control group. Apart from the limitations, the study provides contributions to the scarce literature. To conclude, individuals undergoing warfarin showed a high burden of the DMFT index and need for prostheses. The great number of tooth loss and the demand for oral rehabilitation highlight the need for dental care.