Evaluation of the Effect of Preoperative Amoxicillin on Bacteremia Associated with Exodontia in Periodontal and Periapical Pathology.

AIM: The aim of this study was to evaluate the efficacy of preoperative prophylactic antibiotics of 2 g of oral amoxicillin on bacteremia following extraction of teeth with periodontal and periapical pathology.
MATERIALS AND METHODS: This study was carried out on 160 patients. The patients were divided into four groups of forty patients each: two antibiotic groups, with periodontal and periapical pathology, receiving 2 g of oral amoxicillin preoperatively and two control groups, with periodontal and periapical pathology, receiving no amoxicillin preoperatively. Blood samples were collected before the start of the procedure, intraoperatively, and immediately following extraction of teeth. The collected blood samples were cultured and studied for bacterial growth.
RESULTS: In the control group patients with periodontal pathology, 17 out of 40 blood samples showed growth of Streptococcus viridans along with Staphylococcus epidermidis. In the control group patients with periapical pathology, 14 out of 40 blood samples showed growth of S. viridans and Staphylococcus aureus. No growth was observed in both the groups on prophylactic antibiotics with 2 g of oral amoxicillin.
CONCLUSION: Bacteremia was found in 40% of the control group patients, while there was no bacteremia present in patients with preoperative administration of 2 g of oral amoxicillin. Copyright:

INTRODUCTION

The oral cavity is populated by a diverse, complex endogenous microflora of more than 700 species, 30% of which are streptococci, primarily of the viridans group. It therefore becomes quite apparent that the oral cavity is a potential source of bacteremia and dental treatment procedures may predispose patients with cardiac anomalies to infective endocarditis,[1] if not treated with antibiotic prophylaxis.

The bacteremia incidence appears to be influenced positively by the presence of gingivitis, periodontitis, and odontogenic infections such as dentoalveolar abscess, suggesting a direct relationship between an increased bacterial biofilm burden and bacteremia.[2]

Antibiotic prophylaxis is indicated for patients having compromised immune system such as diabetes mellitus, patients on chemotherapy and radiotherapy, patients on dialysis, and patients with valvular and congenital heart diseases.[3]

This study is to evaluate the efficacy of preoperative prophylactic antibiotics of 2 g of oral amoxicillin on bacteremia following extraction of teeth with periapical and periodontal pathology.

MATERIALS AND METHODS

This study was carried out on 160 patients who reported extraction of teeth with periodontal and periapical pathology. The patients were divided into four groups of forty patients each: two antibiotic groups, each group comprising forty patients with periodontal pathology and forty patients with periapical pathology, receiving 2 g of oral amoxicillin preoperatively and two control groups, each group comprising forty patients with periodontal pathology and forty patients with periapical pathology, receiving no amoxicillin preoperatively.

The indications for surgical removal of the teeth were periodontal or periapical pathology. Patients with underlying systemic condition, metabolic disease, pregnancy, or syndromes were excluded from the study. Patients who were on prior antibiotic therapy were also excluded from this study. All patients included in this study fulfilled the eligibility criteria classified under the American Society of Anesthesiology, Class I for surgery under local anesthesia. Written informed consent for the study was obtained from all the patients.

The patients of each group had three blood samples drawn under aseptic condition. Blood drawn for the antibiotic group was done just before the administration of 2 g of oral amoxicillin, 1 h before the procedure (TI) [Figure 1]. The intraoperative blood sample was drawn 30 s after raising the mucoperiosteal flap (T2) [Figure 2], and the final blood sample was taken immediately 30 s after the delivery of the tooth (T3) [Figure 3]. Blood drawn for the control group was done just before administering local anesthesia (T1) and then at the same intervals (T2, T3) as for the amoxicillin group. Blood samples were collected in brain–heart infusion broth [Figure 4]; the collected samples [Figure 5] were cultured in the laboratory [Figure 6] and studied for aerobic bacterial growth.

Figure 1

Blood draw before injecting local anesthesia

Figure 2

Blood draw after elevation of mucoperiosteal flap

Figure 3

Blood draw after tooth extraction

Figure 4

Brain–heart infusion broth

Figure 5

Collected blood in brain–heart infusion broth

Figure 6

Specimens are kept for incubation

In all the groups, the patients were subjected to assessment of plaque index, gingival index and Russell's periodontal index, clinical examination, and intraoral periapical preoperatively.

RESULTS

Samples collected from 160 patients were evaluated in the laboratory for the presence of bacteremia.

The evaluated results tabulated in Table 1 show the periodontal cases with the control and amoxicillin groups. In the control group, 17 out of 40 samples showed bacterial growth [Figure 7], Streptococcus viridans in blood agar [Figure 8] along with Staphylococcus epidermidis [Figure 9] in the T2 and T3 blood samples. Twenty-three out of forty samples did not show any growth. In the amoxicillin group, none of the samples showed growth.

Table 1

Bacterial growth and preoperative pus in periodontal group

Group	Age range	Age average	Male	Female	Bacterial growth_present	Bacterial growth_absent	Preoperative pus_present	Preoperative pus_absent
Periodontal pathology_control group	32-60	48.7	20	20	17	23	16	24
Periodontal pathology_antibiotic group	35-59	50.8	19	21	0	40	16	24

Figure 7

Samples showing bacterial growth

Figure 8

Streptococcus viridans in blood agar culture medium

Figure 9

Culture showing growth of Staphylococcus epidermidis

Table 2 shows the periapical cases with the control and amoxicillin groups. In the control group, 14 out of 40 samples showed growth of S. viridans in blood agar and Staphylococcus aureus in brain–heart agar medium [Figure 10] in T2 and T3 blood samples. Twenty-six out of forty samples did not show any growth. In the amoxicillin group, none of the other samples showed any growth. The presence of bacteremia in the above described groups is illustrated in Graph 1.

Table 2

Bacterial growth and preoperative pus in periapical group

Group	Age range	Age average	Male	Female	Bacterial growth_present	Bacterial growth_absent	Preoperative pus_present	Preoperative pus_absent
Periapical pathology_control group	21-56	44.9	16	24	14	26	8	32
Periapical pathology_antibiotic group	24-60	44.5	21	19	0	40	6	34

Figure 10

Staphylococcus aureus in brain–heart agar medium

Graph 1

Presence of bacteremia in periodontal and periapical groups

Among the periodontal group, the control group had preoperative pus present in 16 samples, of which 9 had bacteremia, as shown in Table 3. In the periodontal amoxicillin group, 16 samples had preoperative pus, but none of the samples showed growth after incubation. In the periapical group, the control group had preoperative pus present in eight samples, of which four had bacteremia [Table 3]. In the periapical amoxicillin group six samples had preoperative pus, none of the samples showed growth.

Table 3

Preoperative pus and bacteremia

Group	Preoperative pus_present	Presence of bacteremia
Periodontal pathology_control group	16	9
Periodontal pathology_antibiotic group	16	0
Periapical pathology_control group	8	4
Periapical pathology_antibiotic group	6	0

The data were coded and analyzed using the Statistical Package for the Social Sciences (SPSS, version. 20.0; SPSS Inc., Chicago, IL, USA). To test the associations between categorical variables, Chi-square test was applied. The level of statistical significance was kept at P ≤ 0.05. Analysis was done between the test and control groups.

There is a significant association found between administration of antibiotics and bacterial growth in both the periodontal pathology patient group χ(1) =21.587, P ≤ 0.001 and the periapical pathology patient group χ(1) =16.970, P ≤ 0.001.

There is no association found between the presence of pus and bacterial growth in both the periodontal pathology patient group χ(1) =1.506, P = 0.269 and the periapical pathology patient group χ(1) =1.441, P = 0.254.

DISCUSSION

The oral cavity has the second largest diversity of microorganisms after the gut harboring over 700 species.[4] These bacteria gain entry into the bloodstream from oral niches through a number of mechanisms and a variety of portals. Oral tissue trauma caused by procedures, such as extraction of tooth and instrumentation beyond the root apex, will cause breakage in capillaries and small blood vessels that are located within the vicinity of the plaque biofilms leading to spillage of bacteria into the systemic circulation. Higher the microbial load in patients with poor oral hygiene, there is an increased risk of developing bacteremia.[25]

The maximum concentration of bacteria is found in dental plaque.[6] More than 200 different bacterial species have been isolated from the oral cavity in the course of time, though the normal commensals are about twenty in count. The most abundant microorganisms are streptococci of the viridans group (mitis, sanguis, salivarius, etc.).

The disease with which bacteremia traditionally has been associated is bacterial endocarditis (BE) – an infection of the endocardium that causes embolic phenomena and endocardial vegetations. Patient fatalities associated with such alterations have decreased significantly, following antibiotic administration. The microorganisms most commonly associated with BE are S. viridans and S. aureus (21% and 23%, respectively).[6]

The incidence of bacteremia following dental extraction is determined to be between 39% and 100%.[6] Such bacteremia is reported to be of transient nature, since the microorganisms are cleared from the bloodstream within few minutes, but Tomás et al. have reported bacteremia in 20% of patients after 1 h of surgical procedure.[7] Transient bacteremia is frequent with manipulation of the teeth and periodontal tissues, and there is a variation in reported frequencies of bacteremia in patients following dental procedures: tooth extraction (10%–100%), periodontal surgery (36%–88%), scaling and root planing (8%–80%), teeth cleaning (up to 40%), rubber dam matrix/wedge placement (9%–32%), and endodontic procedures (up to 20%).[7]

Diz Dios et al. determined the prevalence of bacteremia with peripheral venous blood sample drawn from each patient at the baseline (before the dental manipulation) and 30 s, 15 min, and 1 h after the dental extraction and revealed that bacteremia peaked at the blood sample drawn at 30 s.[8] In our study, venous blood samples were drawn 30 s after raising the mucoperiosteal flap and final blood sample immediately 30 s after delivery of the tooth.

Takai et al. studied the incidence of bacteremia associated with various oral surgical procedures and concluded that surgical procedure for osteomyelitis resulted in the highest prevalence of positive blood culture (58.3%), closely followed by tooth extraction (57.9%).[9] Maharaj et al. found that 29.6% of their patients developed bacteremia after dental extraction.[10] Heimdahl et al. observed bacteremia in 100% of patients after dental extraction.[11] Lockhart et al. in their study isolated 98 bacterial species. The most commonly isolated genera in their study were Streptococcus (49%), Prevotella (9%), Actinomyces (5%), and Fusobacterium (5%).[12] Okabe et al. in their study found bacteremia in 132 of 183 patients.[13]

In our study, in the control group, 40% of cases showed growth of S. viridans in blood agar and S. epidermidis and S. aureus in brain–heart agar medium. In the amoxicillin group, none of the samples showed growth. The growth of S. epidermidis was probably related to contamination from skin during venipuncture. No anaerobic culture was done in our study, which does not rule out the presence of anaerobic organisms causing bacteremia.

There are inconsistent data available regarding the degree of oral disease necessary to produce bacteremia after oral procedures. Okell and Elliott found that following extraction, the incidence and degree of bacteremia depended on the severity of gingival disease, whereas McEntegart and Porterfield found that the incidence of postextraction bacteremia was unrelated to the extent of oral infection.[1415] In children, Peterson and Peacock found that the bacteremia following dental extraction is unrelated to the local disease, whereas Speck et al. found that bacteremia was more common after removal of abscessed teeth.[1617]

In our study, only nine patients in the periodontal control group and four patients in the periapical control group showed bacteremia despite the presence of pus. Eleven other patients (seven in the periodontal control group and four in the periapical control group) showed no bacterial growth despite the presence of pus in the periodontal and periapical regions.

The results of our study are consistent with the study done by Maharaj et al. who found that amoxicillin given before dental extraction caused a significant decrease in postextraction bacteremia (7.5% vs. 35% in the control group.[10] Krcmery et al. reviewed 339 cases of BE (1991–2001), of which 29.2% were caused by staphylococci and 15% by streptococci.[18] A history of dental surgical procedures was noted in 13.2% of their patients, thus constituting the second most important risk factor after rheumatic fever (24.2%).[18] Duval et al. reported the risk of BE in cardiac patients as one in every 46,000 procedures which were carried without antibiotic prophylaxis, whereas in patients with prophylaxis, it was one in every 150,000 procedures.[19]

The American Heart Association (AHA) (2007) recommends prophylaxis for all procedures involving manipulation of the gingival tissue or periapical region or for procedures causing breach in oral mucosa.[20]

Johnson et al. and Smith et al. documented the antibiotic resistance among the staphylococci and streptococci in patients at high risk of BE.[2122] According to Carmona et al. at least from the medical-legal perspective, it is vigilant to administer antibiotic prophylaxis to those patients with previous history of BE or with heart valve prostheses.[23] In summary, we feel that it is advisable to follow the indications of the AHA regarding the prophylaxis of BE, providing the patient with the necessary information on the associated risks and benefits, and obtaining informed consent in each case.

CONCLUSION

In our study, bacteremia was found in 40% of the control group patients, and no bacteremia was found in patients who received 2 g of oral amoxicillin preoperatively; we also observed that the presence of pus in the periodontal or periapical regions also had no effect on the associated bacteremia. In conclusion, administration of 2 g of oral amoxicillin preoperatively was effective in decreasing bacteremia following extraction of teeth with periodontal and periapical pathology.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.