Different Concentrations Of Chlorhexidine Research Articles

Exploring the effect of chlorhexidine concentration on the biocorrosion behavior of Ti6Al4V for dental implants.

Corrosion of dental implants is one of the most critical factors in the failure of implant treatments. Generally, corrosion depends on the type of material used in implants and the chemical composition of the oral environment. Due to the antibacterial activities, mouthwashes and chlorhexidine gels are often used after implant surgery. Ti6Al4V is commonly used in manufacturing dental implants. The present study aims to investigate the corrosion behavior of the Ti6Al4V alloy under different concentrations of chlorhexidine (0.12%, 0.2%,and 2%) during 2- and 24-h immersion. This way corrosion may be minimized while obtaining an antibacterial environment around the implant. In this regard, the electrochemical behavior of the specimens was investigated using polarization and impedance tests, and then their morphology, cross-section and nano-tribological behavior were evaluated using atomic force microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and nano-scratch test. The results show that using chlorhexidine solution with a concentration of 0.12% could yield a lower corrosion rate and material loss after implant surgery. RESEARCH HIGHLIGHTS: Open circuit potential values increase with immersion time, which suggests multistage passivation of the surface during immersion in chlorhexidine. Specimens in 0.12% chlorhexidine show improved thermodynamic corrosion resistance. Nano-scratch testing demonstrates higher scratch resistance for specimens in 0.12% chlorhexidine solution after 2-h immersion. Higher chlorhexidine concentration than 0.12% and longer immersion times decrease the resistance of the formed passive layer.

Pulmonary Toxicity Assessment after a Single Intratracheal Inhalation of Chlorhexidine Aerosol in Mice.

Guanidine disinfectants are important chemical agents with a broad spectrum of activity that are effective against most microorganisms. Chlorhexidine, one of the most used guanidine disinfectants, is added to shampoo and mouthwash and applied in medical device sterilization. During the use of chlorhexidine, aerosols with micron particle size may be formed, which may cause inhalation toxicity. To assess the toxicity of inhaled chlorhexidine aerosol, mice underwent the intratracheal instillation of different concentrations of chlorhexidine (0, 0.125%, 0.25%, 0.5%, and 1%) using a MicroSprayer Aerosolizer. The mice were exposed for eight weeks and then sacrificed to obtain lung tissue for subsequent experiments. Histopathology staining revealed damaged lung tissues and increased collagen exudation. At the same time, pulmonary function tests showed that chlorhexidine exposure could cause restrictive ventilatory dysfunction, consistent with pulmonary fibrosis. The results of transcriptome analyses suggest that chlorhexidine may trigger an inflammatory response and promote the activation of pathways related to extracellular matrix deposition. Further, we identified that chlorhexidine exposure might enhance mucus secretion by up-regulating Muc5b and Muc5ac genes, thereby inducing fibrosis-like injury. These findings underscore the need for standardized use of disinfectants and the assessment of their inhalation toxicity.

Effect on Cellular Vitality In Vitro of Novel APRF-Chlorhexidine Treated Membranes.

Chlorhexidine (CHX) has been used for some time in clinical practice as a local antiseptic agent with excellent efficacy. The combination of CHX with APRF (Advanced-platelet rich fibrin) membrane has the potential to stimulate tissue regeneration and to provide a bactericidal effect. We hypothesize that this may reduce the rate of infections development and protect cell viability. The aim of this study was two-fold-to create a stable APRF membrane treated with different concentrations of CHX (0.01% and 0.02%) and to monitor its effect on the viability of PDL cells in vitro. This benefits the introduction of a new protocol for APRF membrane production -CHX-PRF and enriches the available evidence on the effect of this antiseptic agent on PDL (Periodontal ligament) cells. APRF membranes were prepared by the addition of two concentrations (0.01% and 0.02%) of CHX. Membranes without the antiseptic were also prepared and used as control samples. PDL cells were cultivated on the membranes for 72 h. Cell number and vitality were examined by fluorescent cell viability assays. Our results demonstrated that a concentration of 0.01% CHX allowed the production of a stable APRF membrane. This concentration slightly reduced the viability of PDL cells to 96.7%, but significantly decreased the average number of cells attached to the membrane-149 ± 16.5 cells/field compared to controls -336 ± 26.9 cells/field. APRF-CHX 0.02% membranes were unstable, indicating a dose-dependent cytotoxic effect of CHX. The introduced novel protocol leads to the production of a new type of APRF membrane-CHX-PRF. The incorporation of an antiseptic into the APRF membrane can improve its bactericidal activity and might serve as an important step for the prevention of postoperative infections.

Comparative efficacy of different concentrations of chlorhexidine for prevention of ventilator‐associated pneumonia in intensive care units: A systematic review and network meta‐analysis

AbstractBackgroundVentilator‐associated pneumonia is a common type of hospital‐acquired infection in critically ill patients. The implementation of effective oral care with chlorhexidine is known to be an effective intervention to prevent ventilator‐associated pneumonia. Nonetheless, no well‐supported evidence exists yet to rank the efficacy of various concentrations of chlorhexidine.AimTo compare the efficacy of different concentrations of chlorhexidine (0.12%, 0.20% and 2.0%) for prevention of ventilator‐associated pneumonia.Study DesignElectronic databases, as well as bibliographies, were systematically searched to find relevant studies published in English from inception until January 1, 2022. We included randomized controlled trials of mechanically ventilated adult patients in intensive care settings comparing at least two of the following treatments: 0.12% chlorhexidine, 0.2% chlorhexidine, 2.0% chlorhexidine, or placebo. The selected outcome was the incidence of ventilator‐associated pneumonia. A frequentist network meta‐analysis was performed. We ranked the concentrations of chlorhexidine for the selected outcome by p score (estimate of the probability of being the best treatment).ResultsWe included 19 trials with 3183 participants, conducted across nine countries. The use of 2.0% chlorhexidine and 0.12% chlorhexidine decreased the risk of ventilator‐associated pneumonia compared with placebo (OR 0.46, 95% CI = 0.28–0.75; OR 0.49, 95% CI = 0.33–0.71, respectively), whereas the effect resulting from 0.02% chlorhexidine remains unclear (OR 0.78, 95% CI = 0.54–1.13). Our network meta‐analysis ranked the 2.0% concentration as the most beneficial for ventilator‐associated pneumonia prevention (p score: 0.92).ConclusionThe 2.0% chlorhexidine and the 0.12% chlorhexidine reduce the risk of ventilator‐associated pneumonia in mechanically ventilated patients. According to the results of our network meta‐analysis, 2.0% chlorhexidine seems more beneficial. Chlorhexidine needs to be further evaluated in large‐scale controlled trials.Relevance to clinical practiceIn patients in intensive care units, and within the inevitable limitations of a network meta‐analysis, this study proposes that 2.0% chlorhexidine is superior to other chlorhexidine concentrations in terms of preventing ventilator‐associated pneumonia.

Efficacy of different preoperative skin antiseptics on the incidence of surgical site infections: a systematic review, GRADE assessment, and network meta-analysis

Surgical site infection (SSI) is the most common postoperative complication and substantially increases health-care costs. Published meta-analyses and international guidelines differ with regard to which preoperative skin antiseptic solution and concentration has the highest efficacy. We aimed to compare the efficacy of different skin preparation solutions and concentrations for the prevention of SSIs, and to provide an overview of current guidelines. This systematic review and network meta-analysis compared different preoperative skin antiseptics in the prevention of SSIs in adult patients undergoing surgery of any wound classification. We searched for randomised controlled trials (RCTs) in MEDLINE, Embase, and Cochrane CENTRAL, published up to Nov 23, 2021, that directly compared two or more antiseptic agents (ie, chlorhexidine, iodine, or olanexidine) or concentrations in aqueous and alcohol-based solutions. We excluded paediatric, animal, and non-randomised studies, and studies not providing standard preoperative intravenous antibiotic prophylaxis. Studies with no SSIs in both groups were excluded from the quantitative analysis. Two reviewers screened and reviewed eligible full texts and extracted data. The primary outcome was the occurrence of SSI (ie, superficial, deep, and organ space). We conducted a frequentist random effects network meta-analysis to estimate the network effects of the skin preparation solutions on the prevention of SSIs. A risk-of-bias and Grading of Recommendations, Assessment, Development, and Evaluation assessment were done to determine the certainty of the evidence. This study is registered with PROSPERO, CRD42021293554. Overall, 2326 articles were identified, 33 studies were eligible for the systematic review, and 27 studies with 17 735 patients reporting 2144 SSIs (overall incidence of 12·1%) were included in the quantitative analysis. Only 2·0-2·5% chlorhexidine in alcohol (relative risk 0·75, 95% CI 0·61-0·92) and 1·5% olanexidine (0·49, 0·26-0·92) significantly reduced the rate of SSIs compared with aqueous iodine. For clean surgery, we found no difference in efficacy between different concentrations of chlorhexidine in alcohol. Seven RCTs were at high risk of bias, 24 had some concerns, and two had low risk of bias. Heterogeneity across the studies was moderate (I2=27·5%), and netsplitting did not show inconsistencies between direct and indirect comparisons. Five of ten studies that mentioned adverse events related to the skin preparation solutions reported no adverse events, and five reported a total of 56 mild events (mainly erythema, pruritus, dermatitis, skin irritation, or mild allergic symptoms); none reported a substantial difference in adverse events between groups. For adult patients undergoing a surgical procedure of any wound classification, skin preparation using either 2·0-2·5% chlorhexidine in alcohol or 1·5% olanexidine is most effective in the prevention of SSIs. For clean surgery, no specific concentration of chlorhexidine in alcohol can be recommended. The efficacy of olanexidine was established by a single randomised trial and further investigation is needed. Dutch Association for Quality Funds Medical Specialists.

Effect of Chlorhexidine (CHX) and Hydrogen Peroxide (H2O2) on the Biofilm Formation of Enterococcus faecalis.

Biofilm makes bacteria resistant to antimicrobial agents and facilitates the transmission of infectious diseases in hospitals. Disinfectant compounds are frequently used to control surface contamination. This study was designed to investigate the effect of chlorhexidine (CHX) and hydrogen peroxide (H2O2) on biofilm formation of Enterococcus faecalis. This study was performed on 40 E. faecalis clinical isolates. After the determination of MIC, the effect of different concentrations of CHX and H2O2 on the biofilm formation was evaluated. Also, the relative expression level of the studied biofilm genes, following exposure to sublethal concentration of CHX and H2O2, was assessed using quantitative reverse transcription PCR (qRT-PCR). The frequency of the asa1, efaA, epaI, and esp biofilm genes were 80%, 92.5%, 100%, and 75%, respectively. Various concentrations of CHX increased the biofilm mass in E. faecalis. Also, the combination of CHX and H2O2 at sub-minimal inhibitory concentrations, significantly elevated the expression of asa1, epaI, and esp genes. The results of this study showed that the improper use of disinfectants can increase the ability of biofilm formation in E. faecalis and may cause selective pressure leading to the emergence of biocide-resistant microorganisms.

The effect of different concentrations of chlorhexidine on microbial colonization: A double-blinded randomized controlled study.

Study aims were to determine the most effective chlorhexidine concentration to be used in reducing microbial colonization in patients under mechanical ventilation and to examine the effect of oral care using different concentrations on the integrity of the oral mucous membranes. This research was a randomized controlled double-blinded experimental study. The sample of study consisted of the 116 adult patients who remained intubated. Oral care was given to patients 4 times/day as per nurse protocol. Every morning during for 4 days, the intraoral mucosa of all groups of patients was assessed. Microbial colonization samples from oral mucosa were taken in the morning before oral care. A determination of the species of microorganisms in these samples was made. A statistically significant difference was found with regard to the reproduction of microorganisms between the oral mucosa samples taken from patients using 2% and 1% chlorhexidine solutions (P < 0.001). In the cultures taken from patients on the first and fourth days of intubation, a total of 36 different microorganisms were seen to be reproducing. It was concluded that the most effective oral solution for the prevention of microbial colonization in patients under mechanical ventilation was chlorhexidine 1%.

Antibacterial and Antifungal Capacity of Three Commercially Available Mouthwashes with Different Concentrations of Chlorhexidine

Chlorhexidine was introduced almost seven decades ago and has a myriad of applications in dentistry. Few studies have evaluated the antimicrobial and antifungal capacity of different concentrations of chlorhexidine mouthwashes. Therefore, the aim of this study, was to evaluate in vitro, the antibacterial and antifungal capacity of three commercially available mouthwashes in Costa Rica, with different concentrations of chlorhexidine, 0.12%, 0.06%, and 0.03%. The experimental method selected was the Kirby-Bauer method to evaluate the antibacterial and antifungal effect of each compound by measuring the inhibitory effect on Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Candida albicans strains, exposed to the antiseptic solutions. All samples showed some degree of antibacterial and antifungal effect. Even though we provide in vitro results, our findings are of relevance since all the species used in our experiment are microorganisms that may be present in dental plaque. Our results further support evidence that oral hygiene regimens may include mouthwashes with low doses of chlorhexidine and maintain reasonable antibacterial and antifungal efficacy.

Investigating the Antioxidant and Cytocompatibility of Mimusops elengi Linn Extract over Human Gingival Fibroblast Cells.

Background—chlorhexidine (CHX) is most commonly used as a chemical plaque control agent. Nevertheless, its adverse effects, including teeth discoloration, taste alteration and calculus build-up, limit its use and divert us to medicinal herbs. The purpose of the study was to evaluate the phytochemical composition, antioxidant potential, and cytotoxic effects of Mimusops elengi Linn extract (ME) over normal human cultured adult gingival fibroblasts (HGFs). Methods—in vitro phytochemical screening, total flavonoid content, antioxidant potential by DPPH and Nitric Oxide (NO) radical scavenging activity, and cytotoxic effects of ME extracts over HGF were explored. The viability of HGF cells was determined using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT), neutral red uptake, and trypan blue assay after treatment with different concentrations of CHX and ME (0.3125 to 10 µg/mL). Results—ME showed some alkaloids, glycosides, saponins and flavonoids exhibited relatively moderate-to-good antioxidant potential. Increasing the concentration of CHX and ME from 0.3125 to 10 µg/mL reduced cell viability from 29.71% to 1.07% and 96.12% to 56.02%, respectively. At higher concentrations, CHX reduced the viability of cells by 52.36-fold compared to ME, revealed by MTT assay. At 10 µg/mL concentration, the mean cell viability of CHX and ME-treated cells was 2.24% and 57.45%, respectively, revealed by a neutral red assay. The viability of CHX- and ME-treated HGF cells estimated at higher concentrations (10 µg/mL) using trypan blue assay was found to be 2.18% and 47.36%, respectively. A paired t-test showed significance (p < 0.05), and one-way ANOVA difference between the mean cell viability of CHX- and ME-treated cells at different concentrations. One-way ANOVA confirmed the significant difference between the viability of CHX- and ME-treated cells. Conclusions—The cytoprotective and antioxidant effects of ME emphasize its potential benefits. Therefore, it could emerge as a herbal alternative and adjunct to conventional oral hygiene methods, that can diminish periodontal tissue destruction.

Important limitations in a trial comparing different concentrations of chlorhexidine and essential oils make it not useful when making decisions

Katsaros T, Mayer E, Palaiologou A, et al. Effect of different concentrations of commercially available mouthwashes on wound healing following periodontal surgery: a randomized controlled clinical trial [published online ahead of print February 19, 2020]. Clin Oral Investig. https://doi.org/10.1007/s00784-020-03232-5.

Comparative evaluation of the effect of curcumin and chlorhexidine on human fibroblast viability and migration: An in vitro study.

Background and Objective:Chemical plaque control acts as an adjunct to mechanical periodontal therapy. Chlorhexidine (CHX) is considered as the gold standard in chemical plaque control, but the main concern is about its fibroblast cytotoxicity. Curcumin, a lipophilic polyphenol, may offer as a promising antiplaque agent. This study was conducted to compare the effect of curcumin (0.003%, 0.03%, 0.06%, 0.1%, and 0.12%) and CHX (0.03%, 0.06%, 0.1%, 0.12%, and 0.2%) on gingival fibroblast cell viability and wound healing at different time periods (1, 2, 4, 6, 8, and 10 min).Materials and Methods:The minimum inhibitory concentration (MIC50) was determined before the evaluation of cytotoxicity and wound healing property. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and morphological examination by direct invert microscopy were carried out to determine cytotoxicity. Wound healing was evaluated by scratch wound assay.Results and Discussion:The MIC50 of CHX and curcumin was at 0.1% and 0.003%, respectively. The mean percentage of fibroblast viability at different concentrations of CHX and curcumin at each time period showed a significant difference. Curcumin exhibited less cytotoxicity as compared to CHX at all concentrations and at varying time periods. There was a significant difference between mean percentage of fibroblast viability at MIC50 of CHX (0.1%) and curcumin (0.003%) at different time periods. The difference between percentage wound healing at antibacterial concentrations of CHX and curcumin at varying time periods was significant.Conclusion:The antibacterial concentration of curcumin (0.003%) exhibits less fibroblast cytotoxicity and excellent wound healing property as compared to CHX. Curcumin may offer as a promising chemical plaque control agent which is less cytotoxic, cost-effective, safe, easily available, and with a possibly beneficial effect on wound healing.

Effects of chlorhexidine, ethylenediaminetetraacetic acid, and sodium hypochlorite on cell viability of human gingival fibroblasts in vitro

Introduction: The aim of this in vitro study was to evaluate the cytotoxic effects of chlorhexidine (CHX), ethylenediaminetetraacetic acid (EDTA), and sodium hypochlorite (NaOCl) irrigants on human gingival fibroblasts. Materials and Methods: Gingival fibroblasts were cultured in Dulbecco Modified Eagle Medium for 24 h. Then, the cells were exposed for 1 min to different concentrations of CHX, EDTA, and NaOCl and the cell viability was assessed using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide tetrazolium reduction assay. The percentage of gingival fibroblast viability was compared to control (100% viability). Results: All concentrations of CHX, EDTA, and NaOCl were cytotoxic to gingival fibroblasts compared to control group and this effect was dose-dependent (P 0.05). Conclusion: The cytotoxic effect of CHX, EDTA, and NaOCl on gingival fibroblasts was dose-dependent. Further studies are needed to assess and optimize the safety and efficacy of these irrigants in vivo.

Synthesization and characterization of chlorhexidine/calcium phosphate/poly(lactic-co-glycolic acid) bone cement

Calcium (Ca) and phosphorus (P) elements are important for bone growth and bone remodeling process while chlorhexidine (CHX) is mainly used as an antiseptic due to its broad antibacterial effects. In this study, CaP nanoparticles were synthesized by a wet chemical route from the precursors of calcium hydroxide (CaOH) and diammonium hydrogen phosphate, (NH4)2HPO4. Poly(lactic-co-glycolic acid) PLGA polymer was incorporated into the mixture of CaP, acted as a matrix binder to form bone cement composite. Different concentrations of CHX (0.5, 1.0, 1.5 and 2.0 mM) were then added into the CaP/PLGA mixtures (CHX/CaP/PLGA bone cements). The bone cements were then characterized by ATR-FTIR, XRD and SEM analyses. The CHX was successfully incorporated into the bone cements, indicated by the appearance of aromatic amine and alkane C–H stretching vibrations which contributed by the ring and long hydrocarbon chain of CHX. The XRD spectra of bone cements showed poorly crystalline phase of apatite. A porous structure of bone cements was also observed with the dispersion of CaP nanoparticles over the PLGA. The CHX/CaP/PLGA bone cement is intended for bone resorption and bone infection applications that require further exploration on its capability to act as bone cement.

The Effect of Chemical Disinfectants on the Setting Time and Dimensional Change of Alginate Impression Material.

Aims: The aim of this study was to evaluate the effect of mixing different concentrations of chlorhexidine, iodine ,and sodium hypochlorite solutions on the setting time and dimensional change of alginate impression material. Materials and methods: Total number of samples (40) has been prepared in this study. Ten samples for control group made from pouring alginate impressions of metal model .The other groups made by mixing alginate with 0.05% iodine, 0.5% chlorhexidine and 0.5% sodium hypochlorite solutions. Dimensional change was measured with AutoCAD program .The Setting time was also measured for each group. Statistical analysis was performed using ANOVA and Duncan multiple range test. Results: no significant difference in the linear dimensional change among the tested groups ,sodium hypochlorite added to alginate as disinfectant showed the highest dimensional changes among the other groups. There was a significant difference among the tested groups in the setting time. It was found that treating the alginate with sodium hypochlorite and chlorhexidine disinfecting agents accelerated the setting time of the material. Conclusion: The testing disinfecting agents can be used safely regarding dimensional change.

Polydopamine-assisted chlorhexidine immobilization on medical grade stainless steel 316L: Apatite formation and in vitro osteoblastic evaluation

Immobilization of chlorhexidine (CHX) on stainless steel 316L (SS316L), assisted by a polydopamine film as an intermediate layer is projected as an approach in combating infection while aiding bone regeneration for coating development on orthopedic and dental implants. This study aimed to investigate the ability of CHX coating to promote apatite layer, osteoblast cells viability, adhesion, osteogenic differentiation and mineralization. Stainless steel 316L disks were pre-treated, grafted with a polydopamine film and immobilized with different concentrations of CHX (10–30mM). The apatite layer formation was determined through an in vitro simulated body fluid (SBF) test by ATR-FTIR and SEM-EDX analyses. The osteoblastic evaluations including cells viability, cells adhesion, osteogenic differentiation and mineralization were assessed with human fetal osteoblast cells through MTT assay, morphology evaluation under FESEM, ALP enzyme activity and Alizarin Red S assay. The apatite layer was successfully formed on the CHX coated disks, demonstrating potential excellent bioactivity property. The CHX coatings were biocompatible with the osteoblast cells at low CHX concentration (<20mM) with good adhesion on the metal surfaces. The increment of ALP activity and calcium deposition testified that the CHX coated disks able to support osteoblastic maturation and mineralization. These capabilities give a promising value to the CHX coating to be implied in bone regeneration area.

Alexidine versus chlorhexidine for endodontic irrigation with sodium hypochlorite.

Objective:The objective of this study was to chemically evaluate precipitate formation on irrigation by different concentrations of chlorhexidine (CHX) and alexidine (ALX) with sodium hypochlorite (NaOCl).Materials and Methods:Six test tubes were prepared with 1 ml of 4% NaOCl. One milliliter of 2%, 1%, 0.5%, and 0.25% ALX was added to the first four, and in the last two, 1 ml of 2% CHX and 0.2% CHX was added, respectively. Samples were observed for color changes or precipitates at multiple time intervals. All solutions were then centrifuged at 1000 rpm for 10 min and re-examined for precipitates. This process was repeated twice. Fifty freshly extracted premolars were biomechanically prepared, dried, divided into two groups, and irrigated with 10 ml of 4% NaOCl and 10 ml of 2% ALX (Group 1) and 10 ml of 4% NaOCl and 10 ml of 2% CHX (Group 2). These samples were sectioned and observed for precipitates on the dentinal surfaces by scanning electron microscopy (SEM).Results:The color of the solution of ALX and NaOCl stayed transparent and no precipitate was observed. A color change was noted immediately on mixing CHX and NaOCl which did not change with time. Precipitates were only observed in the solutions of CHX with NaOCl and after centrifuging them. SEM views also showed dense precipitates covering the dentinal surface and occluding the dentinal tubules in Group 2.Conclusion:The interaction of ALX and NaOCl does not produce precipitates which together with its better antimicrobial action make ALX a more effective and safer replacement for CHX as an adjunctive endodontic irrigant.

EFFICACY OF ATRAUMATIC RESTORATIVE TREATMENT USING GLASS IONOMER CONTAINING CHLOROHEXIDINE: IN VIVO AND IN VITRO STUDY

Introduction: The atraumatic restorative treatment (ART)considered a trusted and effective approach to the control of carious lesions.Since the ART approach using glass ionomer (GICs) the use of antimicrobial agents(chlorhexidine) in combination with restorative materials are being developed for reducing the frequency and severity of secondary caries. hence, it is preferable to keep an optimum chlorhexidine concentration to maintain its antimicrobial effect without affecting GICs’ mechanical performance. Aim of the study: This study was planned to evaluate the antibacterial activity and mechanical properties of the glass ionomer containing different concentrations of chlorhexidine. Material and methods: In vivo study: Sixty children aged 7-9 years old were included in this studywith at least onecavitated dentin carious lesion in occlusal surfacesin primary teeth.these children were randomly divided into three equal treatment groups. Group I: atraumatic restorative treatment approach using a conventional glass ionomer cement. Group II: atraumatic restorative treatment approach using glass ionomer containing1% chlorhexidine. Group III: atraumatic re­storative treatment approach using glass ionomer containing 2% chlorhexidine. A sample was taken from the affected dentine using a sterile sharp small-size hand excavator at baseline and after 7 days. All samples were inoculated for the selective isolation of mutans streptococci, and lactobacilli. In vitro study: Fifteen cylindrical specimens for each group were prepared and tested for their compressive strength, diametral compressive strength and microhardness. Results: The percentage reduction in mean and standard deviation (SD) of mutans streptococci and lactobacilli between treatment groups revealed that there were statistically significant differences between three groups (P= 0.01, P= 0.02).Tukey post hoc test revealed that the main difference was between glass ionomer containing chlorohexidine and conventional glass ionomer while there was no statistically significant difference between glass ionomer containing 1% and 2% chlorohexidine. The comparison of the mechanical properties among the three groups in term of compressive strength, diametral compressive strength and microhardness showed no statistically significant differences between conventional glass ionomer and glass ionomer containing 1% or 2% chlorohexidine. Conclusion: Glass ionomers containing chlorhexidine displayed superior antibacterial activity than conventional glass ionomers without affecting the mechanical properties of glass ionomer

Red fluorescence of dental biofilm as an indicator for assessing the efficacy of antimicrobials.

The study aimed to determine whether the red fluorescence (RF) of a dental microcosm biofilm as measured with quantitative light-induced fluorescence (QLF) technology is useful for assessing the efficacy of antimicrobials. Dental microcosm biofilms were formed on bovine enamel discs and grown under 0.3% sucrose challenge and treated with chlorhexidine (CHX) solutions at different concentrations (0.05%, 0.1%, and 0.5%) plus a negative control [sterile distilled water (DW)] twice daily for 7days. The biofilms were photographed using a QLF-digital system to evaluate the RF by calculating the red/green ratio, and pH values of the medium were measured daily. After 7days, the bacterial viability of the biofilm was assessed by measuring the counts of viable total bacteria and aciduric bacteria, and the percentage surface microhardness changes (%SHC) was evaluated. The RF and cariogenic properties were compared for the different concentrations of CHX, and their correlations were examined. The RF and its increase rate were much lower for CHX-treated biofilms than for DW-treated biofilms. The RF after 7days of maturation decreased significantly with increasing CHX concentrations (p<0.001) and was from 31% (for 0.05% CHX) to 46% (for 0.5% CHX) lower than that of the DW group. Strong correlations were reported between the RF of the 7-day-maturation biofilms and cariogenic properties, such as the number of total bacteria (r=0.93), number of aciduric bacteria (r=0.97), supernatant pH (r=0.43), and %SHC (r=0.98). In conclusion, the RF of dental biofilms as measured with QLF technology can be used to nondestructively assess and monitor the effect of antimicrobials against biofilm.

Effect of supragingival oral irrigation as an adjunct to toothbrushing on plaque accumulation in chronic generalized gingivitis patients.

Aim:The aim of this study was to evaluate the efficacy of supragingival oral irrigation either with water or different concentrations of chlorhexidine (CHX) digluconate as an adjunct to toothbrushing on plaque accumulation in chronic generalized gingivitis patients.Materials and Methods:Fifty patients were randomly allocated into five groups. Group 1: toothbrushing alone, Group 2: toothbrushing with mouthwash, Group 3: toothbrushing with water irrigation, Group 4: toothbrushing with 0.0075% CHX digluconate (36 mg) supragingival irrigation, and Group 5: toothbrushing with 0.02% CHX digluconate (96 mg) supragingival irrigation. The collected data were subjected to statistical analysis.Statistical Analysis:Descriptive data were obtained for all outcome variables and reported as mean ± standard deviation. The Student's t-test, Chi-square test, and one-way analysis of variance (ANOVA) were applied for the statistical evaluation of means and comparisons of proportions, and post hoc Bonferroni test was used for multiple comparisons after the application of the ANOVA test for comparison within the groups.Results:When intergroup difference of the mean differences was compared for individuals using toothbrushing along with 0.0075% CHX digluconate irrigation and those using toothbrushing along with 0.02% CHX digluconate irrigation from BL-14, BL-28, and between 14 and 28 days, it was found to be statistically nonsignificant.Conclusions:In our study, the CHX digluconate concentration for mouthwash and oral irrigation in addition with toothbrushing was found to be same, i.e., <50 mg for improving the gingival health by reducing gingival inflammation.

Free Active Chlorine in Sodium Hypochlorite Solutions Admixed with Octenidine, SmearOFF, Chlorhexidine, and EDTA

IntroductionThe therapeutic effects of sodium hypochlorite (NaOCl) solutions are dependent on the levels of free available chlorine (FAC). Mixing these solutions with irrigants can result in significant reductions in FAC. Although the effect of some irrigants on FAC is known, the effect of other commonly used irrigants is not. Thus, the therapeutic ramifications of the concurrent use of these on the efficiency of NaOCl solutions is not known. MethodsAliquots of 5.2% (w/v) NaOCl solutions were admixed in proportions of 90:10, 80:20, and 50:50 with the following irrigants: octenidine dihydrochloride (OCT); SmearOFF (Vista Dental Products, Racine, WI), 17% EDTA; and 0.2%, 2%, and 5% chlorhexidine (CHX) solutions. Changes in FAC were measured by iodometric titration. Statistical differences between means were determined using a post hoc Tukey analysis test after an analysis of variance. ResultsOCT appeared not to affect FAC and was significantly different than all other irrigants, except for 90:10 and 80:20 mixtures of low concentration (0.2%) CHX. CHX solutions showed a marked concentration- and mixture proportion–dependent detrimental effect on FAC. The reduction of FAC between different concentrations of CHX was statistically significant in 80:20 and 50:50 proportions, with 50:50 mixtures of 5% CHX having the greatest influence. Mixtures containing even small proportions of SmearOFF or EDTA exhibited significant losses in FAC. ConclusionsOCT has little effect on FAC and can be used concurrently with NaOCl solutions. Higher concentrations of CHX significantly affect FAC. Their combined use with NaOCl solutions should be avoided. EDTA and SmearOFF should not be mixed with NaOCl solutions.