Antibacterial Effect Of Chlorhexidine Research Articles

Mutans streptococci growth on glass ionomer incorporated with chlorhexidine: in-vivo study

Background: glass ionomer is one of the most frequently used restorative materials for primary teeth restoration. It has been in use for more than 30 years. Their restoration usefulness is preferential compared to other restorations due to their fluoride release and recharge, chemical adhesion to the structure of the dentin and their range of uses. Increasing the antibacterial efficacy of restorative materials is one of the primary goals to decrease the incidence of recurrent caries. Chlorhexidine is the gold standard antibacterial agent in dentistry. Objectives: the objective of this study is to evaluate the antibacterial effect of Chlorhexidine incorporated with glass ionomer on streptococcus mutans. Methods: Thirty Children between ages ranged 6-9 years old were selected to participate in this study. Children with bilateral caries in lower second primary molars affecting the occlusal and proximal surfaces without pulpitis were included in the study. All cavities were divided into two groups; group (A) restored with Glass Ionomer and group (B) restored with Glass Ionomer Chlorhexidine mixture. The sound proximal surfaces in all cavitated teeth acted as a control. After one month, two months and three months’ plaque samples were obtained and streptococcus mutans counts were calculated. Results: The number of SM taken from sound proximal surfaces for all groups were not changed significantly in whole periods of study. At the all-time interval, the mean log10 of SM in CHX group was lower than GI group and the difference was statistically significant. There is a significant difference in the mean log10 of SM in CHX group between the 1St month and the 3rd month. Conclusion: The growth of SM was found to be higher in the sound tooth than in GI groups and in GI group was higher than in CHX- GI mixture up to three months.

Effect of electric currents on antibacterial effect of chlorhexidine against Entrococcus faecalis biofilm: An in vitro study.

BackgroundThis in vitro study was mainly aimed to evaluate the effect of high-frequency alternating currents (AC) applied by an electronic apex locator (EAL) on the antibacterial properties of chlorhexidine (CHX) on E. faecalis biofilm.Material and MethodsThe root canals of 120 extracted human single-rooted teeth were prepared using Gates-Glidden drills and hand K-files. After contaminating the root canals with E. faecalis, they were incubated for 60 days. Then, the teeth were randomly divided into six experimental groups (n=20). Group 1, 2% CHX; group 2, normal saline (NS) with direct current (DC); group 3, normal saline (NS) with high-frequency alternating current (AC); group 4, 2% CHX with DC; group 5, 2% CHX with AC; group 6, control (normal saline). The samples were collected from the root canal walls of 16 teeth in each group and 1:10 serial dilutions were prepared and added to Muller-Hinton agar (MHA) plates and incubated at 37°C for 48 h. The longitudinal sections of the other 4 teeth used to observe under a scanning electron microscope (SEM). A classic colony counting technique was used for counting the vital E. faecalis bacteria in MHA. Two-way ANOVA was used for statistical analysis of the data. The level of significance was set at P<0.05.ResultsThe electric current significantly changed the colony-forming units (CFU) values (P<0.001). According to pair-wise comparisons, the highest CFU difference was observed between the AC group and the group without electric current (P<0.001); furthermore, the difference between the DC group and the group without electric current was not significant (P=0.823).ConclusionsThe highest bioelectric effect occurred with the use of high-frequency alternating electric current in the form of an apex locator with CHX as a canal irrigant. Key words:Biofilm, Chlorhexidine, Direct current, Electric current, Enterococcus faecalis.

Comparison Between Antibacterial Effect of Chlorhexidine 0.2% and Different Concentrations of Cyperus rotundus Extract: An In vitro Study.

Aims and Objectives:Modern methods of caries prevention concentrated on natural ingredients usage such as probiotics and polyphenols that are safer for young children with Streptococcus mutans inhibitory properties. The purpose of this study was to compare antibacterial effects of different concentration of Cyperus rotundus extract and chlorhexidine (CHX) 0.2% mouthwash on S. mutans and Lactobacillus acidophilus.Materials and Methods:In this in vitro study, the antibacterial effectiveness of the C. rotundus extract and CHX was compared with minimum inhibitory concentration (MIC) test in tube, minimum bactericidal concentration (MBC) test in solid medium, and disc diffusion for measurement of inhibition zone. Data were analyzed using one-way ANOVA, one sample t-test, and independent sample t-test statistical methods by SPSS. 24 software (SPSS Inc., Chicago, USA).Results:MIC and MBC values of the C. rotundus extract were obtained 225 and 450 mg/ml, respectively, for S. mutans and 108 and 225 mg/ml for L. acidophilus, which are more than CHX (0.5, 1 res.). The inhibition zone increased in a dose-dependent manner but lower than CHX.Conclusion:The C. rotundus extract had antibacterial effects (bactericide and bacteriostatic) on S. mutans and L. acidophillus. Although this effect was lower than CHX. With regard to adverse effect of CHX, this extract can be a potential antibacterial agent.

Chlorhexidine-releasing orthodontic elastomerics.

The aim of this study was to identify the best combination of chlorhexidine (CHX) with orthodontic elastomerics for prevention of oral disease in orthodontic patients. We used ethyl cellulose (EC) as the polymer, and experimental groups were divided into five groups according to differences in solvent (i.e., ethanol; EtOH, dichloromethane; DCM). CHX release from the coated elastomerics was evaluated with a UV spectrophotometer and observed by scanning electron microscope (SEM). The antimicrobial release increased over time for 48 h in Group 3 (CDA+EC+30% EtOH/70% DCM), exhibiting the longest sustained-release characteristics (p<0.001). It also showed the highest antimicrobial properties, which was confirmed by inhibition zone testing using S. mutans (p<0.05). All groups were not affected when tensile force was tested in the coated elastomerics. We conclude that the antibacterial effect of CHX can be adjusted according to combinations of polymers and solvents. Group 3 exhibited the best substantivity and antimicrobial properties.

Antibacterial effect of chlorhexidine on bacteria adsorbed onto experimental dental plaque

The most common method used to examine the antibacterial effect of antiplaque agents is the minimal inhibitory concentration (MIC) method, which is tested on bacteria in suspensions. Examining the antibacterial effect on bacteria adsorbed onto dental surfaces models is not as popular, although it is clear that such models reflect the conditions in the oral cavity far more accurately than the conventional MIC method. The antibacterial effect of chlorhexidine (CHX) on bacteria adsorbed onto experimental dental plaque model was investigated. Hydroxyapatite beads were coated with human saliva. Next, cell-free fructosyltransferase (FTF) and glucosyltransferase (GTF) were adsorbed onto the beads, and sucrose was added to allow the synthesis of polysaccharide by the surface-bound enzymes. Following adsorption of Streptococcus sobrinus to the experimental dental plaque (EDP), the EDP was exposed to CHX at concentrations between 0.008 to 0.0002% at pH values of 5.5, 6.5, and 7.5. After 150 min incubation, growth of the adsorbed bacteria was measured by their incorporation of 3H-uridine or 3H-thymidine. Comparison of bacterial growth on the EDP with that in suspension showed that the surface-bound bacteria were less sensitive to CHX than were the bacteria in suspension. At all tested CHX concentrations, the antibacterial effect was independent of pH. In addition, under our experimental conditions, the use of 3H-uridine as an indicator of bacterial viability proved to be more sensitive than 3H-thymidine. The antibacterial effect of an agent in a model closely mimicking the tooth surface should generate results that are more relevant to the in vivo conditions than are conventional methods, thus bearing significant information concerning clinical applications of CHX.

Further in vivo studies on the plaque‐inhibiting effect of chlorhexidine and its binding mechanisms

The aim of the present study was to investigate the relative importance of chemical groups in the oral cavity which bind chlorhexidine of clinical significance. This was performed by clinical experiments where a test panel of 11 individuals rinsed with chlorhexidine at pH 7, pH 5.5, and pH 3. Rinsing with 0.02 M EDTA was performed prior to the chlorhexidine rinse, because this procedure has been shown to enhance the antibacterial effect of chlorhexidine in vitro. However, pre-rinses with EDTA did not increase the clinical effect of chlorhexidine. Bacteriologic tests showed comparable antibacterial effect of chlorhexidine at pH 7 and pH 3. Mouthrinses of pH 7 and pH 5.5 had comparable plaque-inhibiting effects, whereas the effect of a rinse of pH 3 was not different from that of the placebo. This finding is interpreted to suggest that primary phosphate (pK about 2) is an important receptor site for chlorhexidine, whereas secondary phosphate (pK = 7.0) is of negligible importance. Previous studies have clearly shown that phosphate binds chlorhexidine. The lack of clinical effect at pH 3 is probably due to precipitation of salivary proteins by hydrogen ions, making primary phosphate groups unavailable for interaction with chlorhexidine.

The effect of handcream on the antibacterial activity of chlorhexidine gluconate

A series of handwashing experiments compared the residual effect on Escherichia coli of non-medicated soap, chlorhexidine detergent followed by an anionic handcream, chlorhexidine detergent followed by a non-ionic handcream and chlorhexidine detergent alone. Handcreams containing an anionic emulsifying agent reduced the antibacterial effect of chlorhexidine.