PREVALENCE OF ESCHERICHIA COLI AND ENTEROCOCCUS FAECALIS IN PULP SPACE OF HUMAN DECIDUOUS TEETH WITH IRREVERSIBLE PULPITIS

Dr. Preeth Shetty , Reader, Department of Pedodontics and Preventive Children Dentistry
A.B. Shetty Memorial Institute of Dental Sciences.
Miss Adrija Kar, Final Year BDS, A.B. Shetty Memorial Institute of Dental Sciences.

ABSTRACT

The present day primary teeth endodontics has been plagued with over prescription of antibiotics to children. Has there been a change in the microflora of primary tooth pulp space over the time,  is the present day antibiotic regimen potent enough to control the infection, these questions has led us to do this study. The purpose of this study was to evaluate the prevalence of Escherichia coli and Enetrococcus faecalis in the pulp space of human primary teeth with irreversible pulpitis in order to assess the present day regimen of antibiotics if it is potent enough to control the infection. The results showed a very low prevalence of both E coli and E Faecalis.

Introduction

Primary or deciduous teeth serves many function such as : help provide nutrition, help make speech possible , aid in the normal development of jaw bones and facial muscles, add to an attractive appearance reserves space for permanent teeth and help guide them into position.

The teeth with pulpal and periapical problems, specifically the primary teeth, should be retained until their normal exfoliations because their premature loss may lead to undesirable aberrations in the future dentition. Root canals harbors different types of microorganisms and provide an ideal culture media for bacterial growth.

The success of endodontic treatment depends on many factors and the reduction or elimination of bacterial infection is the most important one. However, for this to occur it is important to identify which bacterial species are present in deciduous teeth with pulp necrosis and periapical infection.¹
Enterococii are common inhabitants of the human gastro intestinal and genitor urinary tract. They are also able to colonize a variety of other sites, including oral cavity Enterococii have also been implicated in endodontic infections. Among the Enterococii species isolated from root canals, Enterococuss faecalis (E. Faecalis) is the most common species. It is a non fastidious, therapy resistant microorganism in infected root canals. However it constitutes a small percentage of the microbial species isolated from root canals of teeth with necrotic dental pulp. ²
It can be hypothetized that E. faecalis could be present in untreated canals, but in low numbers that it is not recovered due to the changes in root canal environment this microorganism may grow to higher and recoverable portions. Numerous studies showed that E.faecalis has some special characteristics that allow them to survive in conditions that are commonly lethal for many other organisms. These properties include an ability to grow in high salt concentrations, a wide temperature range, tolerance   a broad pH range, as well as persist in the presence of intra canal medicaments.
E. faecalis has some virulence factors which are already identified and could be the lesion for survival of this microorganism in a very harsh environment of the root canal system: secreted factors, adhesins, surface structures such as capsular polysaccharides and antibiotic resistance determinant. E. faecalis has special capacities as endopathogen to invade dentinal tubules and adhere to dentin surface .³

The lipotechoic acid and lipo polysaccharides present in Escherichia Coli (E. Coli) affects the pulp leading to destruction of pulp tissues. Lipoteichoic acid and lipo polysaccharides are components of the bacterial cell wall that can induce pulp inflammation and periapical infections, including lethal cellular aggression.4 The aim of the study is to check the prevalence of E. Coli and Enterococcus  faecalis in the pulp chambers of deciduous molars.  

Method and Materials

Method of collection

30 children between the age of 3 and 8 years of both sexes visiting to the department of Pedodontics and Preventive dentistry, A.B. Shetty Memorial Institute of Dental Sciences, Mangalore were selected for study
Deciduous teeth with reversible pulpits with intact root or less than 2/3 of physiological root resorption, no chemical and radiographic evidence of perapical lesion, no periodontal pocket and no previous root canal intervention, with no antibiotics received by patients for 4 weeks prior to smapling were used. The selected teeth were isolated with rubber dam and field of operation (exposed tooth, clamp & rubber dam) will be disinfected with two applications of 30% hydrogen peroxide followed by 5% tincture iodine
After caries removal sterile paper points were inserted into the pulp chamber for 60 seconds these paper points were inoculated into thioglycolate broth supplemented with vit K and hemin. The collected samples were streaked on to Mac Conkeys agar plates and Muller Hinton agar plates for the specific isolation of E. Coli & E. faecalis. The plates were incubated aerobically at 37degree C for 18-24 hours.11, 12 The bacterial colonies were identified based on the gram staining & specific biochemical tests.
E. Coli – Indole test, Methyl Red test, V.P test, Citrate test, Triple sugar iron agar test
E. faecalis – Bile Esculin test

Results

The results of the study showed that out of 30 samples 7 samples showed the presence of E.faecalis and 3 samples showed the presence of E.coli.
Statistical analysis: (fig 1,2)
Percentage of E.faecalis: 23.33%
Percentage of E.coli  : 10%
Note:  since this is a descriptive type of study and there is comparison of prevalence between only two bacteria, much of statistical analysis was not needed.

Discussion

During 1950’s and 60’s researches isolated mainly aerobic & facultative bacterial species form root canals with necrotic pulp and periapical lesions due to limitation of technique and microbial culture.13 Earlier studies using culture methods have reported that E. faecalis is not normaly present or is present in very low numbers in untreated canals. Rocas et al14 and  Fouad  et al15 reported a smaller occurrence (18% and 8% respectively) of E. faecalis using molecular techniques.
This study estimated the prevalence of E. faecalis and E. coli in the root canals of deciduous molars. Primary root canal infections are caused by microorganisms colonizing the necrotic pulp tissue and impairing its function the development and spread of pulpal infection is related to a number of factors such as caries, trauma or an iatrogenic cause. 16
Our study shows that the prevalence of E. faecalis is 7 out of 30 and E. coli is 3 out of 30 samples. In other studies, it has been showed that the most frequent microorganisms isolated from infected root canals were gram positives among there E. faecalis was the species most frequently isolated agreeing with the finding of Molander et al17, Peciuliene et al18, Pinheiro et al19 ,Gomes et al.20
The presence of E. faecalis & E. coli in the root canals of the deciduous teeth of young individuals will add knowledge about the presence of these microorganisms in the oral cavity since early stages.
The results of the study indicate that new treatment plan should be discovered to eliminate infection during treatment & improve prognosis.

Summary

E.faecalis  and E.coli are the two bacteria fond in the deciduous teeth . the aim of this study is to determin the prevalence of E.faecalis and E.coli in the pulp space of deciduous teeth with irreversible pulpitis. 30 samples were collected on multiple paper points and inoculated into thioglycolate broth supplemented with vitamin k and hemin . The collected samples were streaked on to Mac Conkeys agar plates and Muller Hinton agar plates for the specific isolation of E. Coli & E. faecalis. The plates were incubated aerobically at 37degree C for 18-24 hours. The bacterial colonies were identified based on the gram staining & specific biochemical tests.
The result showed that out of thirty samples 7 showed presence of E.faecalis and E.coli.
The study concluded that E.faecalis is low and E.coli is very low in primary endodontically infected teeth.  This study needs to be extended with introduction of commonly used antibiotic regimen and then assess the potency of newer antibiotics.

Conclusions

Studies have indicated that the prevalence of E. faecalis is low and E. Coli is very low in primary endodontic infections and high in persistent infections. E. faecalis is also more commonly associated with asymptomatic cases then with symptomatic ones. Although E. faecalis and E. coli possesses several virulence factors, its ability to cause periradicular disease stems from its ability to survive the effects of root canal treatment and persists as a pathogen in root canal and dentinal tubules of teeth. Our challenge is to implement methods to effectively eliminate these microorganisms during and after treatment. Currently use of good aseptic technique, increased apical preparation sizes, and inclusion of full strength sodium hypochlorite and 2% chlorhexidine irrigants are the most effective methods to eliminate E. faecalis and the mechanisms that enable it to cause persistent endodontic infections. In the changing face of dental care, continued research on E. faecalis & its elimination from the dental apparatus may well define the future of the endodontic specialty

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Fig : 1 Representing the results in bar chart

Fig 2 : Representing the result in pie chart