D Babu, N Reddy, D Swaroop, K Babu, K Kiran, M Swaminathan
bacteremia, infective endocarditis, periodontal probing
D Babu, N Reddy, D Swaroop, K Babu, K Kiran, M Swaminathan. Evaluation Of Bacteremia Following Periodontal Probing In Gingivitis And Periodontitis Patients.. The Internet Journal of Dental Science. 2009 Volume 9 Number 2.
Infective endocarditis is a rare, potentially fatal disease where susceptible endocardium or a prosthetic heart valve is colonized by microorganisms such as streptococci, staphylococci, and Candida. It is well recognized that dental procedures, which induce bacteremia of substantial magnitude, have an increased potential to induce infective endocarditis in susceptible hearts1.
The human oral cavity has a large, varied population of bacterial organisms, particularly in the gingival crevice. In healthy gingiva, a thin surface mucosa of epithelium separates potentially pathogenic organisms from the general circulation, which supplies gingiva2 through the cervical plexus of capillaries. These microorganisms are considered normal inhabitants and non pathogenic of oral cavity as long as they are confined within the mouth3. But inflammation in gingiva may result in gingival ulceration around the tooth, which results in discontinuity of this mucosal barrier4. After dissolution of the continuity of the mucous membrane, microorganisms may reach the blood stream and cause complications to the body. This kind of bacteremia may be associated with chewing of food, brushing of the teeth and particularly after any oral surgical procedure. In healthy persons, the episodes of bacteremia are brief due to efficient clearance by the host immune system. However in many patients with impaired resistance owing to drug usage, damaged organs or suffering from diseases such as valvular heart disease, diabetes and acquired immune deficiency syndrome, bacteremia is associated with an increased risk of serious complications like infective endocarditis3.
As prevention of infective endocarditis is desirable, due to its high rates of morbidity and mortality, there is a general consensus that all patients with predisposing heart conditions be given appropriate antimicrobials prior to operative procedures that may give rise to infective endocarditis. This is based on the fact that infective endocarditis may follow a bacteremia and that certain dental procedures can produce bacteremia with organisms having potential to cause infective endocarditis1. According to American Heart Association, periodontal probing is under high-risk category for infective endocarditis5 and recommends antibiotic prophylaxis for patients at risk since periodontal probing is done for all patient’s seeking dental treatment as a part of assessment of periodontal status.
Aims And Objectives
To investigate the occurrence of bacteremia due to periodontal probing in a group of patients with gingivitis as compared to a group with periodontitis.
To identify the microorganisms present within positive blood cultures [by aerobic culture].
To assess factors such as age, sex, plaque index, oral hygiene index-simplified, number of teeth probed, number of sites that bleed on probing, total probing depth and mean probing depth per teeth for any association with bacteremia.
Materials And Methods
Forty adult patients, who have attended the dental out patient ward of department of periodontics, Rajah muthiah dental college and hospital, annamalai university, aged between 20 and 70 years, including males and females were randomly selected for the study. The ethical committee for research work of Annamalai University gave clearance to carry out the present study and procedure was explained to patients and was included, only after signing the consent form. Patients who have at least 15 natural teeth were included and Patients with history of periodontal treatment of any form in the preceding 3 months, congenital or acquired cardiac defect or cardiac prosthesis, hematological disorder or immune defect and patients taking antibiotics in the previous month or who were taking corticosteroids or immunosuppressive medication were excluded from the study.
Study procedure involved the following steps:
Initial Blood Sampling
Initial blood sampling was obtained by venipuncture from antecubital vein. Before obtaining blood, the area was wiped with povidone iodine and with 70% iso propyl alcohol and allowed to dry 5 ml of blood was obtained by means of disposable syringe. Immediately the blood sample was transferred into culture bottle containing biphasic medium of 50ml of brain heart infusion agar and brain heart infusion broth.
During clinical examination oral hygiene index-simplified [OHI-S] - by Greene and Vermilion6 -1964, plaque index - by Loe and Silness6 -1964 were recorded:
Periodontal probing was done for all teeth using a standard periodontal probe [Michigan ‘o’ probe with Williams markings].probing was done on mesial, mid, distal surfaces of buccal and lingual aspects of all the teeth. Probe was inserted parallel to the long axis of the teeth and presence or absence of bleeding, probing depth at that particular site was recorded simultaneously.
Final Blood Sampling
Immediately 30 seconds after periodontal probing, second blood sample was collected [5ml] under aseptic conditions and transferred to the culture bottle containing brain heart infusion agar and brain heart infusion broth.
Selected patients for the study were divided based on bleeding on probing and probing pocket depth into gingivitis [patients who had≥12 sites that bleed on probing] and periodontitis [patients who had atleast six teeth with ≥5 mm of pocket depth] groups, with each group consisting of 20 patients [Patients later found not to fit into any category after probing and clinical examination were excluded].
Micro Biological Investigations
Brain heart infusion agar was prepared as per the instructions of the manufacturer, sterilized and 50 ml was poured into the sterile culture bottle. This was allowed to solidify on one side of the bottle; the following day, brain heart infusion broth was prepared as per the instructions of the manufacturer, sterilized and 50ml was added to the solid medium and stored in refrigerator until future use.
Blood samples which were collected were incubated for 48 hours at 370C. Culture bottles after 48 hours were examined for any turbidity. The bottles which signaled positive were taken and sub cultured on to blood agar plates. The streaked plates were incubated at 370C for 24-48 hours and observed for growth of any colonies[Fig 3,4]. The organisms were confirmed by Gram’s staining method. The bottles were observed for a period of seven days for growth. If there was no growth a blind sub culture was done from the bottles on to blood agar, before being discarded as negative. Smears were prepared from the suspected colonies on a new glass slides which were air dried and heat fixed. The smears were then subjected to Gram staining.
The morphology of the bacteria like shape, arrangement was observed and grouped into gram positive cocci and gram negative bacilli. Gram positive cocci in chains with the property of alpha-hemolysis on blood agar plates were confirmed as streptococcus viridians [Fig 3]. Gram positive cocci in clusters with the property of Beta-hemolysis on blood agar plates were confirmed as staphylococcus aureus by coagulase test [Fig 4].
Statistical analysis was done for the data collected from parameters-age, sex, number of teeth probed, oral hygiene index-simplified, plaque index, number of sites that bleed on probing, total probing depth, mean probing depth. The statistical package used for analysis was SPSS [statistical package for social science]. Median, range were estimated for parameters age, number of teeth probed, oral hygiene index-simplified, plaque index, number of sites that bleed on probing, total probing depth, mean probing depth. Median test was employed to compare the median values for the above parameters. Since the values were not equally distributed, proportion was estimated for the parameter sex. Proportions were estimated from the samples for each group. Proportions were compared by pearson’s chi- square test with Yates continuity correction / fisher’s exact [2 tailed] appropriately. In the present study, P<0.05 was considered as the level of significance.
Out of 20 gingivitis patients, none had exhibited positive bacteremia before probing, while 3 [15%] had exhibited positive bacteremia after probing. Out of 20 periodontitis patients, none had exhibited positive bacteremia before probing, while 9 [45%] had exhibited positive bacteremia after probing [Table 1]. Microorganisms recovered were
In the present study, median values for age [p value <0.0001], oral hygiene index-simplified [p value 0.0005], plaque index [p value 0.0007], number of sites that bleed on probing [p value 0.03], total probing depth [p value 0.005], mean probing depth [p value <0.0005], were significantly higher in periodontitis group than in gingivitis group. Number of teeth probed [p value 0.004] is significantly higher in gingivitis group than in periodontitis group in the present study. Median test was employed to estimate the P value. The proportion of males - 12 out of 20 , females - 8 out of 20 in gingivitis group is statistically not significant when compared to males – 14 out of 20, females-6 out of 20 in periodontitis group. Pearson’s chi-square test with Yates continuity correction was used to estimate the P value [table 3].
Median values for Age [p value 0.08], number of teeth probed [P value 0.73], oral hygiene index-simplified [P value 0.08], plaque index [P value 0.98] were statistically not significant when compared to bacteremia positive [n = 12] and bacteremia negative [n = 28] patients. The inference is that, these parameters have got no influence on incidence of bacteremia among the above groups in the present study. Median values for number of sites that bleed on probing [P value <0.0001], total probing depth [P value 0.0004], mean probing depth [P value 0.0001] were significantly higher in bacteremia positive patients when compared to bacteremia negative patients. The inference is that the incidence of bacteremia increases with number of sites that bleed and total probing depth, among the above patients in the present study. Out of 12 [75%], females - 3 out of 12 [25%], in bacteremia positive patients was statistically not significant [P value 0.48], when compared to proportion of males - 17 out of 28 [60.7%], females - 11 out of 28 [39.3%] in bacteremia negative patients. The inference is that the parameter sex has no influence on incidence of bacteremia among the above patients. Fisher’s exact test [2 tailed] was employed to determine the P value [table 4].
Infective endocarditis is a disease in which microorganisms colonize the damaged endocardium on heart valves. The incidence of infective endocarditis in the developing countries is 1 to 5 new cases per lakh per year1. Certain dental procedures are capable of producing bacteremia, which can eventually lead to infective endocarditis. The micro flora of the oral cavity can be a potential source of bacteremia after disruption of capillaries in the gingival tissues7. This kind of transient bacteremia is well documented following tooth extraction, following treatments for periodontal diseases such as gingivectomy, supra and sub gingival scaling8. Based on available literature about 15 to 40 percent of endocarditis cases could be due to dental treatment8. Generally such bacteremia poses little threat to a healthy patient however, patients at a high risk for cardiovascular infection because of various cardiac lesions, such as rheumatic heart disease, congenital defects, valvular disease, or prosthetic implants could be seriously compromised by this kind of bacteremia9.
In the present study, the presence of microorganisms following probing was identified by aerobic culture since, aerobic/gram positive bacteria were mostly implicated in the pathogenesis of infective endocarditis.
The incidence of bacteremia in gingivitis group was 15%, this is in accordance with the study done by Max Winslow et al10 who showed 9.5% of bacteremia in gingivitis group. The incidence of bacteremia in periodontitis group was 45%,this finding was in accordance with findings of Christopher G Daly et al11-43%, Max Winslow et al10- 42% , John lofthus12- 30%, Aldona et al13- 61%, James Felix et al14- 50%, and Thomas Witzenberger et al15 - 55%. In the present study microorganisms recovered were
Plaque index, number of sites that bleed on probing, total probing depth, mean probing depth per tooth were significantly higher in periodontitis group than in gingivitis group, which were in accordance with the study done by Christopher G. Dal11.
Oral hygiene index-simplified which was not included in any of previous studies, but included in the present study was significantly higher in periodontitis group than in gingivitis group.
In the present study the median of age in bacteremic patients was 40.5 years as against 29 years in non bacteremic patients, which was statistically insignificant. The association of age with bacteremia could not be evaluated with certainty by different authors. The studies conducted by Thomas Witzenberger et al15, James Felix et al14, Luther lineberger et al17, could not find any association between age and bacteremia. However Okabe et al18 based on his study observed that the incidence of bacteremia tends to increase with age of the patient.
There was no significant difference in the occurrence of bacteremia between males and females in the present study, which is in accordance with the study done by Christopher G. Daly et al11, K.okabe et al18, Luther lineberger et al17.
There was no significant difference found for number of teeth probed, plaque index in occurrence of bacteremia which was in accordance with the study done by Christopher G. Daly et al11. Studies done by Thomas Witzenberger et al15, Victoria Lucas et al19, coulter W.A et al20 showed that plaque index was not associated with bacteremia which is similar to the present study. Oral hygiene index-simplified was also not statistically significant in occurrence of bacteremia in the present study.
Since the factors age, sex, number of teeth probed, plaque index, and oral hygiene index-simplified showed no significant difference between positive bacteremic patients and negative bacteremic patients, it seems that these factors do not predict which patients will show bacteremia from periodontal probing.
The lack of association between bacterial plaque and presence of bacteremia was most likely due to fact that plaque assessments were made with naked eye. It is nearly impossible for small levels of plaque to be detected in this way. The tooth surface would always be colonized by some plaque which is not visible to the naked eye. Such sub ocular levels of plaque nevertheless are scooped down by the tip of periodontal probe as it is traversing the tooth surface in the region of gingival crevice21.
Number of sites that bleed on probing, mean probing depth per tooth, were significantly associated with occurrence of bacteremia in the present study and this is in accordance with the study done by Christopher G. Daly et al11. Total probing depth is also significantly associated with bacteremia which differs from Christopher G. Daly et al11.
The probe tip is known to penetrate through the epithelial lining of the pocket when inflammation is present and bleeding on probing is indicative of an inflammatory lesion in the underlying connective tissue. Bleeding sites, but not non bleeding sites, show histologic ulceration of the pocket epithelium. Thus whenever bleeding on probing occurred, any microorganisms dislodged from the plaque biofilm by the probe tip may have had chance to spread into vascular connective tissue and then into circulation system11. This may explain why the number of sites which bleed on probing was significantly associated with bacteremia.
Since in the present study, the incidence of bacteremia was found to be more in periodontitis group, and the factors which were associated with bacteremia i.e. number of sites that bleed on probing, total probing depth, mean probing depth per tooth were also significantly higher in periodontitis group than in gingivitis group, patients with untreated periodontitis were at greater risk of experiencing bacteremia due to periodontal probing. Since these factors cannot be measured until after probing was performed, they are of no use to the clinician as predictive factors for bacteremia prior to probing, and the only factor which was significantly predictive for the occurrence of bacteremia prior to probing was the presence of interproximal bone loss on dental panoramic or intra oral periapical. radiographs. This method of screening for alveolar bone loss has been shown to correlate well with the presence of periodontitis8. In the previous study done by Christopher G. Daly et al11 with untreated periodontitis and who exhibited bone loss on dental panoramic radiographs, experienced 43% of bacteremia following periodontal probing, which coincides well with the present study.
Thus for an individual adult with periodontitis who has not received any periodontal treatment within the previous year, may have at least 45% chance of bacteremia occurring following periodontal probing.
Based on the findings of this study, it can be concluded that patients with untreated periodontitis were at a greater risk of experiencing bacteremia due to periodontal probing. This study also indicates the importance of history taking to determine the presence of or past history of rheumatic fever, rheumatic heart diseases or any other valvular heart diseases. In individuals evidencing such background, it would be appropriate to advocate prophylaxis even before periodontal probing was done.