Examination of periodontal pathogens in stenotic valve specimens and in whole blood samples in patients affected by aortic valve stenosis and chronic periodontitis

The Oral Microbiota in Valvular Heart Disease: Current Knowledge and Future Directions

Oral microbiota formation begins from birth, and everything from genetic components to the environment, alongside the host's behavior (such as diet, smoking, oral hygiene, and even physical activity), contributes to oral microbiota structure. Even though recent studies have focused on the gut microbiota's role in systemic diseases, the oral microbiome represents the second largest community of microorganisms, making it a new promising therapeutic target. Periodontitis and dental caries are considered the two main consequences of oral bacterial imbalance. Studies have shown that oral dysbiosis effects are not limited locally. Due to technological advancement, research identified oral bacterial species in heart valves. This evidence links oral dysbiosis with the development of valvular heart disease (VHD). This review focuses on describing the mechanism behind prolonged local inflammation and dysbiosis, that can induce bacteriemia by direct or immune-mediated mechanisms and finally VHD. Additionally, we highlight emerging therapies based on controlling oral dysbiosis, periodontal disease, and inflammation with immunological and systemic effects, that exert beneficial effects in VHD management.

Detection of Periodontal Pathogens in Oral Samples and Cardiac Specimens in Patients Undergoing Aortic Valve Replacement: A Pilot Study

This observational study aimed to: (i) assess the presence of periodontal disease among patients requiring aortic valve replacement; (ii) investigate the presence of oral pathogens in aortic valve specimens and compare them with the microorganisms detected in the oral cavity. Twenty-six patients (15 men and 11 women) were scheduled to be visited the day before the cardiac surgery: periodontal conditions were accurately registered through clinical and radiographic examinations; dental plaque or salivary samples were collected. Valve specimens were collected during surgical aortic valve replacement and analyzed for pathogens detection through microbiological 16SrRna gene sequencing. Bacteria found in plaque samples and valve specimens were assessed according to oral and periodontal conditions. A qualitative comparison between oral and cardiac profiles of the microorganisms detected was performed. The overall number of patients examined for soft tissues conditions was 19, as 7 patients were edentulous. Twelve and three individuals, respectively, presented moderate and severe periodontitis. Nine valves were found to be positive for the presence of oral and periodontopathic bacterial DNA. The microbial species found in valve samples of patients with periodontitis suggest that the presence of these microorganisms in valvular tissue seems to be not coincidental.

Periodontitis is associated with incidental valvular heart disease: A nationwide population-based cohort study

AIM

Periodontitis and valvular heart disease (VHD) are common diseases. Both diseases are related to chronic inflammation and share many common risk factors. Previous periodontal studies had focused mainly on atherosclerotic cardiovascular disease. This study aimed to determine whether periodontitis is associated with the development of VHD.

MATERIALS AND METHODS

This was a retrospective nationwide cohort study using Taiwan's Longitudinal Health Insurance Database. Using ICD-9-CM coding, both the periodontitis and non-periodontitis groups were matched.

RESULTS

There were 8483 cases and 4919 cases of VHD diagnosed in the periodontitis group and non-periodontitis group, respectively. The cumulative incidence of VHD was significantly higher in the periodontitis group (log-rank test, p < .001), with the incidence density of 6.44 (95% CI, 6.31-6.58) per 1000 person-years in the periodontitis group compared to 4.65 (95% CI, 4.52-4.78) in the non-periodontitis group. The relative risk for VHD was 1.39 (95% CI, 1.34-1.44). After multivariate analysis, periodontitis was independently associated with a risk for VHD (HR, 1.38; 95% CI, 1.33-1.42, p < .001). Intensive treatment of periodontitis significantly lowered the risk for VHD (HR, 0.68; 95% CI, 0.60-0.77, p < .001).

CONCLUSIONS

Periodontitis was significantly associated with the development of VHD. Treatment of periodontitis reduced the risk for VHD.

Association between periodontal bacteria and degenerative aortic stenosis: a pilot study

Purpose

Although several reports have described the relationship between periodontal disease and cardiovascular disease, information about the association between periodontal disease and the progression of degenerative aortic stenosis (AS) is lacking. Therefore, we performed a retrospective, single-center, pilot study to provide insight into this potential association.

Methods

Data from 45 consecutive patients (19 men; median age, 83 years) with mild or moderate degenerative aortic stenosis were analyzed for a mean observation period of 3.3±1.9 years. The total amount of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis and titers of serum immunoglobulin G (IgG) against periodontal bacteria and high-sensitivity C-reactive protein (hs-CRP) were evaluated. Aortic valve area (AVA), maximal velocity (Vmax), mean pressure gradient (mean PG), and the Doppler velocity index (DVI) were evaluated. The change in each parameter per year ([Parameter_LATEST–Parameter_BASELINE]/Follow-up Years) was calculated from the retrospective follow-up echocardiographic data (baseline vs. the most recently collected data [latest]).

Results

No correlation was found between the concentration of periodontopathic bacteria in the saliva and AS status/progression. The anti-P. gingivalis antibody titer in the serum showed a significant positive correlation with AVA and DVI. Additionally, there was a negative correlation between the anti-P. gingivalis IgG antibody titer and mean PG. The hs-CRP concentration showed positive correlations with Vmax and mean PG. Meanwhile, a negative correlation was observed between the anti-P. gingivalis IgG antibody titer and ΔAVA/year and Δmean PG/year. The hs-CRP concentration showed positive correlations with Vmax and mean PG, and it was significantly higher in patients with rapid aortic stenosis progression (ΔAVA/year <−0.1) than in their counterparts.

Conclusions

Our results suggest that periodontopathic bacteria such as A. actinomycetemcomitans and P. gingivalis are not directly related to the status/progression of degenerative AS. However, inflammation and a lower immune response may be associated with disease progression.

Prior oral conditions in patients undergoing heart valve surgery

Background

Patients scheduled for heart valve surgery should be free of any oral infectious disorders that might pose a risk in the postoperative period. Few studies have been made on the dental conditions of such patients prior to surgery. The present study describes the most frequent prior oral diseases in this population group.

Material and Methods

A prospective, observational case-control study was designed involving 60 patients (30 with heart valve disease and 30 controls, with a mean age of 71 years in both groups). A dental exploration was carried out, with calculation of the DMFT (decayed, missing and filled teeth) index and recording of the periodontal parameters (plaque index, gingival bleeding index, periodontal pocket depth, and attachment loss). The oral mucosa was also examined, and panoramic X-rays were used to identify possible intrabony lesions.

Results

Significant differences in bacterial plaque index were observed between the two groups (p<0.05), with higher scores in the patients with valve disease. Probing depth and the presence of moderate pockets were also greater in the patients with valve disease than among the controls (p<0.01). Sixty percent of the patients with valve disease presented periodontitis.

Conclusions

Patients scheduled for heart valve surgery should be examined for possible active periodontitis before the operation. Those individuals found to have periodontal disease should receive adequate periodontal treatment before heart surgery.

Key words:Valve disease, aortic, mitral, heart surgery, periodontitis.

The effect of blue light on periodontal biofilm growth in vitro

We have previously shown that blue light eliminates the black-pigmented oral bacteria Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, and Prevotella melaninogenica. In the present study, the in vitro photosensitivity of the above black-pigmented microorganisms and four Fusobacteria species (Fusobacterium nucleatum ss. nucleatum, F. nucleatum ss. vincentii, F. nucleatum ss. polymorphum, Fusobacterium periodonticum) was investigated in pure cultures and human dental plaque suspensions. We also tested the hypothesis that phototargeting the above eight key periodontopathogens in plaque-derived biofilms in vitro would control growth within the dental biofilm environment. Cultures of the eight bacteria were exposed to blue light at 455 nm with power density of 80 mW/cm2 and energy fluence of 4.8 J/cm2. High-performance liquid chromatography (HPLC) analysis of bacteria was performed to demonstrate the presence and amounts of porphyrin molecules within microorganisms. Suspensions of human dental plaque bacteria were also exposed once to blue light at 455 nm with power density of 50 mW/cm2 and energy fluence of 12 J/cm2. Microbial biofilms developed from the same plaque were exposed to 455 nm blue light at 50 mW/cm2 once daily for 4 min (12 J/cm2) over a period of 3 days (4 exposures) in order to investigate the cumulative action of phototherapy on the eight photosensitive pathogens as well as on biofilm growth. Bacterial growth was evaluated using the colony-forming unit (CFU) assay. The selective phototargeting of pathogens was studied using whole genomic probes in the checkerboard DNA-DNA format. In cultures, all eight species showed significant growth reduction (p < 0.05). HPLC demonstrated various porphyrin patterns and amounts of porphyrins in bacteria. Following phototherapy, the mean survival fractions were reduced by 28.5 and 48.2% in plaque suspensions and biofilms, respectively, (p < 0.05). DNA probe analysis showed significant reduction in relative abundances of the eight bacteria as a group in plaque suspensions and biofilms. The cumulative blue light treatment suppressed biofilm growth in vitro. This may introduce a new avenue of prophylactic treatment for periodontal diseases.

Porphyromonas gingivalis in periodontal pockets and heart valves

BACKGROUND

There is evidence that advanced infectious chronic periodontal inflammatory disease may have an impact on general health including cardiovascular diseases. The aim of this clinical study was to evaluate the ability of Porphyromonas gingivalis to colonize heart valves and, subsequently, to assess whether there is an association between the presence of the DNA of Porphyromonas gingivalis in periodontal pockets and in degenerated heart valves.

MATERIALS AND METHODS

Thirty patients were enrolled in the study and 31 valve specimens harvested during cardiac surgery operations were examined. All patients underwent a periodontal examination. To evaluate the periodontal status of the patients the following clinical parameters were recorded: the pocket depth, bleeding on probing (BOP) and aproximal plaque index (API). The presence of P. gingivalis in heart valve specimens and samples from periodontal pockets was analyzed using a single-step PCR method.

RESULTS

P. gingivalis DNA was detected in periodontal pockets of 15 patients (50%). However, the DNA of this periopathogen was found neither in the aortic nor in the mitral valve specimens.

CONCLUSIONS

This study suggests that P. gingivalis may not have an influence on the development of the degeneration of aortic and mitral valves.

Phototargeting human periodontal pathogens in vivo

The effects of blue light at 455 nm were investigated on the bacterial composition of human dental plaque in vivo. Eleven subjects who refrained from brushing for 3 days before and during phototherapy participated in the study. Light with a power density of 70 mW/cm(2) was applied to the buccal surfaces of premolar and molar teeth on one side of the mouth twice daily for 2 min over a period of 4 days. Dental plaque was harvested at baseline and again at the end of 4 days from eight posterior teeth on both the exposed side and unexposed sides of the mouth. Microbiological changes were monitored by checkerboard DNA probe analysis of 40 periodontal bacteria. The proportions of black-pigmented species Porphyromonas gingivalis and Prevotella intermedia were significantly reduced on the exposed side from their original proportions by 25 and 56 %, respectively, while no change was observed to the unexposed side. Five other species showed the greatest proportional reduction of the light-exposed side relative to the unexposed side. These species were Streptococcus intermedius, Fusobacterium nucleatum ss. vincentii, Fusobacterium nucleatum ss. polymorphum, Fusobacterium periodonticum, and Capnocytophaga sputigena. At the same time, the percentage of gingival areas scored as being red decreased on the side exposed to light from 48 to 42 %, whereas the percentage scored as red increased on the unexposed side from 53 to 56 %. No adverse effects were found or reported in this study. The present study proposes a new method to modify the ecosystem in dental plaque by phototherapy and introduces a new avenue of prophylactic treatment for periodontal diseases.