The effect of argon laser and chlorhexidine on klebsiella pneumoniae isolated from root canal content

The present study undertaken to identify klebsiella pneumoniae from root canal samples of clinically symptomatic nonvital teeth having periapical on first opening of root canal of 27 such intact teeth and to identify the effect of argon laser and chlorhexidine on isolated Klebsiella pneumoniae. Out of 27 samples, positive cultures were 30 samples and the isolated bacteria included Staphylococcus aureus ,klebseilla pneumonias , streptococcus mutans ,Pseudomonas aeroginosa and, E.coli.The result it showed that the minimal inhibitory concentrations of chlorhexidine disinfectant(mouth wash)for Klebseilla pneumoniae were ranged from 0.014-0.11μg\ml Also it is found that Klebsiella pneumoniae completely killed after exposure to argon laser for 10-16 minutes Introduction: Periapical pathos's is considered as an endogenous infection caused by oral microflora .Bacterial infection of dental pulp results in pulpal destruction and subsequently stimulates an inflammatory cell response and destruction of bone in the perapex (1) .The relationship between bacterial infection of dental pulp and periapical lesion formation has been elegantly demonstrated in the classic studies of Kakehashi et al (2) . Many investigators have attempted to isolate and identify various microorganisms from root canals and periapical lesions (3,4,5,6) . Convincing evidence has accumulated that infections of root canals are polymicrobial infections. Further ,Hashioka correlated the clinical symptoms with microorganisms isolated from root canals of symptomatic non vital teeth (7) .Over the years ,changes in the type of bacteria isolated and their antibiotic sensitivity have been identified and pattern of resistance to various antibiotics have been developed (8) . The Argon laser was invented in 1964 by William Bridges at Hughes Aircraft and is one of a family of Ion lasers that use a noble gas as the active medium (9) . This laser is used in many applications such as: Forensic Medicine, Entertainment, General Surgery, Ophthalmic Surgery, Holography, Optical "pumping" source (9) . Argon has approximately the same solubility In water as oxygen gas and is 2.5 times more soluble in water than nitrogen gas. Argon is colorless, odorless, tasteless and nontoxic in both its liquid and gaseous forms. Argon is inert under most conditions and forms no confirmed stable compounds at room temperature (10) . .Although argon is a noble gasIt has been found to have the capability of forming some compounds. For example, the creation of argon hydrofluoride (HArF), a metastable compound of argon with fluorine hydrogen, was reported by researchers at the University of Helsinki in 2000 (10) . Although the neutral ground-state chemical compounds of argon are presently limited to HArF, argon can form clathrates with water when atoms are trapped in a lattice of the water molecules. (11) Also argon-containing ions and excited state complexes, such as ArH+ and ArF, respectively, are known to exist. Theoretical calculations have shown several argon compounds that should be stable but for which no synthesis routes are currently known Argon laser has killing effect on Klebsilla sp. and Pseudomonas sp ( 12 ) . Chlorhexidine is an antimicrobial agent used to control oral diseases ,it consists of molecules with both hydrophilic and hydrophobic properties (13) .It has a broad antimicrobial spectrum and is generally more effective against gram-positive than against gram –negative bacteria (14) . Aim of study : This study was carried out to evaluate the effect of argon laser and chlorhexidin on klebseilla pneumonias isolated from root canal content. Material and Method: Twenty seven male and female patients with age group of 19-54 years attended Dental Hospital in Tikrit university were included in this study. Each patient have at least one intact non vital tooth, presenting with one or more of the following symptoms:Spontaneous pain, Pain on percussion , Swelling. An X-ray of the involved tooth was taken and teeth showing periapical pathos's were included in the study. The sample were taken under strict aseptic conditions. The involved tooth was isolated under a rubber dam.The field was disinfected with tincture of iodine and the access cavity was prepared with a sterile round bur. On gaining access to the pulp, a sterile reamer/file/broach was inserted into the root canal up to the apical foramina and root canal content were obtained for culture. Next reamer or file containing root canal contents was placed in a sterile test tube, sealed and transferred to the laboratory. Root canal contents were inoculated on Blood agar and MaConkey agar then incubated at 37 o C for 18 – 24hrs. Colony characteristics were noted in case of any growth and identification of microorganisms was done according to the morphology using gram staining and by biochemical reactions (15,16,17,18,19,20,21) .Determination of minimal inhibitory concentrations of chlorhexidine double dilutions of chlorhexidine of different concentrations ranged between 0.014 -7.2 μg |ml in MacConkey agar plates were prepared .A fresh inoculums of the tested bacteria in MacConkey broth and incubated at 37 o C overnight . All plates were inoculated with broth culture of bacteria and incubated at 37 o C for 24 hours . Each agar plates containing Klebsiella pneumoniae are exposed to argon laser light with output 150 mW, 515 nm at distance 15cm from lens for 2 to 16 minutes ,was utilized against klebsiella pneumoniae isolated in the present study (22) .The results were read to the end of visible growth . Results: The distribution of pathogenic bacteria among patients showed that Klebsiella pneumoniae was the most common pathogen isolated from female than male as shown in tables (1,2).The MICs (Minimal Inhibitory Concentrations )of chlorhexidine for klebsilla pneumonia isolated from root canal content ranged between 0.014 – 0.11 μg /ml ( Table 3) . Table (4),revealed that all klebsiella pneumoniae isolated from root canal content were killed after exposure to argon laser light for 10 minutes . The decrease in number of living bacteria increased with increasing the time of exposure to laser light . Table (1) :Sex distribution of isolated klebsiellae pneumoniae. Sex No .of isolated klebsilla pneumonia