Chlorhexidine use after two decades of over-the-counter availability

Predicting the occurrence of antagonism within ternary guanidine mixture pollutants based on the concentration ratio of components

The widespread prevalence and coexistence of diverse guanidine compounds pose substantial risks of potential toxicity interactions, synergism or antagonism, to environmental organisms. This complexity presents a formidable challenge in assessing the risks associated with various pollutants. Hence, a method that is both accurate and universally applicable for predicting toxicity interactions within mixtures is crucial, given the unimaginable diversity of potential combinations. A toxicity interaction prediction method (TIPM) developed in our past research was employed to predict the toxicity interaction, within guanidine compound mixtures. Here, antagonism were found in the mixtures of three guanidine compounds including chlorhexidine (CHL), metformin (MET), and chlorhexidine digluconate (CDE) by selecting Escherichia coli (E. coli) as the test organism. The antagonism in the mixture was probably due to the competitive binding of all three guanidine compounds to the anionic phosphates of E. coli cell membranes, which eventually lead to cell membrane rupture. Then, a good correlation between toxicity interactions (antagonisms) and components' concentration ratios (pis) within binary mixtures (CHL-MET, CHL-CDE, MET-CDE) was established. Based on the correlation, the TIPM was constructed and accurately predicted the antagonism in the CHL-MET-CDE ternary mixture, which once again proved the accuracy and applicability of the TIPM method. Therefore, TIPM can be suggested to identify or screen rapidly the toxicity interaction within ternary mixtures exerting potentially adverse effects on the environment.

The Effectiveness of Herbal Versus Non-Herbal Mouthwash for Periodontal Health: A Literature Review

Dental plaque is a biofilm of microorganisms that present naturally on the exposed tooth surface; it is the main etiological factor for many periodontal conditions and other oral health issues and its regular removal from the oral cavity can prevent many periodontal problems. Despite several experiments using herbal oral care products to reduce dental plaque or gingivitis, the findings remain inconclusive. We performed a systematic literature search on PubMed and Cochrane Library for randomized controlled trials (RCTs) dating from 2001 up to and including the year 2021. The keywords and Medical Subject Headings (MeSH) terms comprised combinations of the following: herbal, clove oil, peppermint oil, ginger, basil, ajwain, betel leaf extract, neem, lavender, non-herbal, chlorhexidine, fluorides, hydrogen fluoride, hydrogen fluoride, stannous fluoride, and mouthwashes. Each of the titles that the search elicited was screened and duplicates were removed from the gathered results. The full-text versions of the remaining articles were downloaded and examined by title and abstract. Handsearching was not carried out. We initially identified 21 studies; 14 studies, which did not fulfill the selection criteria, were excluded. All the included studies reported a reduction in plaque index (PI) and gingival index (GI) scores in both herbal and non-herbal groups. Two studies reported the superiority of the non-herbal mouthwash over the herbal one while five of the studies showed no significant difference in PI and GI scores between herbal and non-herbal mouthwash, implying equal efficacy of both, i.e., Triphala, aloe vera, tea tree, and polyherbal groups like Zingiber officinale, Rosmarinus officinalis, and Calendula officinalis, and chlorhexidine. Current research suggests that herbal mouthwashes are as effective as non-herbal mouthwashes for reducing dental plaque in the short term; however, the evidence is based on low-quality trials.

Chemical plaque control - A brief review

Dental plaque is a complex microbial population of bacterial and salivary polymers present on the tooth surface. It is understood that human diseases must be avoided and a high social concern for the population as a whole. The argument for the implementation of successful prevention measures is strong for life-threatening diseases or those with serious morbidity. However, regardless of seriousness, the case for avoiding any disease may be based on the belief that it is easier to be healthy than dead or sick. Thus plaque prevention is an efficient way to both treat and avoid periodontal diseases, it is an important component of gingival and periodontal diseases' primary management.

Efficacy of an aluminium triformate mouthrinse during the maintenance phase in periodontal patients: a pilot double blind randomized placebo-controlled clinical trial

BACKGROUND

The aim of this prospective placebo-controlled pilot study was to evaluate short-term effects of a mouthrinse containing aluminium triformate (ATF) on gingival inflammation and plaque formation in periodontal patients who are in the maintenance phase. ATF has styptic (astringent) and anti-inflammatory effects.

METHODS

Forty non-smoking periodontal patients with modified sulcus bleeding index (MSBI) ≥40 % were randomly divided into two groups. The participants received a masked mouthrinse (ATF or placebo) and were instructed with the rinsing protocol of 3 daily rinses during 30 s for 7 days. One blinded investigator (CE) performed all clinical examinations. The primary outcome was reduction in gingival inflammation as measured by MSBI. The secondary outcomes were reduction of the amount of plaque as measured by plaque index (PI) and approximal plaque index (API) and the occurrence of side effects. The patients were evaluated at the start and the end of the rinsing period, including the compliance of the patients.

RESULTS

MSBI was reduced in both groups compared to baseline, but the ATF group showed significantly more reduction in MSBI compared to the placebo group (ATF: 17.6 %, placebo: 7.6 %, p = 0.035). ATF and placebo had no effects on dental plaque. Patients reported ATF mouthrinse not to have side effects other than oral sensation, whereas compliance of the patients was good. Almost all patients in the ATF group reported reduction of gum bleeding after 1 week of rinsing with ATF.

CONCLUSIONS

This short-term pilot clinical trial is a firm basis to design a long-term controlled clinical trial to show whether ATF helps to inhibit further periodontal breakdown in maintenance patients with high MSBI.

TRIAL REGISTRATION

This trial was registered in the WHO International Clinical Trials Registry Platform as DRKS00007672 , date of registration: 21/01/2015.

Acute pulmonary toxic effects of chlorhexidine (CHX) following an intratracheal instillation in rats

Chlorhexidine (CHX) is a cationic biguanide compound that has been widely used for disinfection of skin, mucous membranes, and medical instruments. Poisoning has been occurred occasionally due to its easy accessibility. Some fatal cases developed acute respiratory distress syndrome (ARDS) from aspiration of CHX directly into the lung. There is no preclinical information about the pulmonary toxicity of CHX available since the products of CHX are usually developed for disinfection by topical use. In this study, the acute pulmonary toxic effects of CHX following an intratracheal instillation in rats were investigated. Rats were exposed either to CHX at concentrations of 0.02% and 0.2% or to distilled water at a volume of 500 μl/kg b.w. CHX at concentration of 0.2% caused changes in hematological and biochemical values including white blood cell count (WBC), total protein (TP), albumin (ALB), lactate dehydrogenase (LDH), blood urea nitrogen (BUN) and creatinine (CRE), and induced inflammatory reactions including intra-alveolar edema and hemorrhages, as well as resulted in the target organ concentration in lungs at the level of about 1.0 μg/g and maintained for more than 1 week, when administered intratracheally in rats. The cytotoxic action of CHX might induce those detrimental reactions in rats.

Comparing the effects of chlorhexidine and persica on alveolar bone healing following tooth extraction in rats, a randomised controlled trial

Chlorhexidine is broadly prescribed by clinicians for treating extraction socket wounds; however, studies have reported adverse effects for chlorhexidine. Persica, a herbal antibacterial agent, could be an alternative for chlorhexidine. The aim of this randomised controlled trial was to investigate the effects of persica and chlorhexidine on alveolar bone healing following tooth extraction in rats. Eighteen Wistar rats were randomly allocated to three study groups: 0.2% chlorhexidine, 10% persica and controls (tap water). The rats were mouth-rinsed for 14 days. On day 8, the mandibular right first molars of all the rats were extracted. On day 21, the rats were euthanized and histological slides of their extraction sockets were prepared. The amount of new bone formation and the number of inflammatory cells in the extraction socket for each rat were recorded. Data were analysed using linear regression and Mann-Whitney tests. There was no significant difference between the control group and the intervention groups in terms of new bone formation and inflammatory cell count. The mean new bone formation was significantly higher in the persica group than in the chlorhexidine group. There was a significant association between new bone formation and inflammatory cell count in the entire sample. In conclusion, there were no significant differences between rinsing with tap water and rinsing with 0.2% chlorhexidine and 10% persica in enhancing extraction socket wound healing in rats. Extraction socket wound healing in rats was better enhanced with 10% persica than 0.2% chlorhexidine.

A prospective randomized trial to reduce oral Candida spp. colonization in patients with hyposalivation

Low salivary flow rates are associated with higher oral Candida spp. counts, which may predispose to oral candidiasis. The aim of this study was to compare the effect of stimulating salivary flow rates with that of a regimen of chlorhexidine mouth rinse on the intensity of Candida colonization in patients with reduced salivary flow rates. Thirty-one outpatients were randomized to stimulate salivary output (group 1) or to receive chlorhexidine mouth rinses (group 2). Evaluations were performed at baseline (T0), at end of treatment (T1), and 15 days after last day of treatment (T2). Chewing-stimulated whole saliva samples were collected at each visit. Group 1 showed a constant reduction in median cfu counts, although the difference was significant only between T0 and T2 (p = 0.004). Group 2 showed a reduction in median Candida cfu counts between T0 and T1 (p = 0.01), but the counts increased at T2 (p = 0.01), and the difference between T0 and T2 was not significant (p = 0.8). In conclusion, patients who received salivary stimulation showed reductions of Candida cfu counts in saliva and a trend for increasing salivary flow rates between baseline and end of study evaluations. The use of chlorhexidine mouth rinses dramatically reduced Candida cfu counts, but when patients discontinued treatment, intensity of colonization rose again.

The Peritoneal Explant Test for Evaluating Tissue Tolerance to Mouthrinses

The tissue cultures of explants of neonatal rat peritoneum have been demonstrated to be a sensitive test for tissue compatibility with wound antiseptics. The present study investigated the suitability of this method to assess the relative toxicity of mouthrinses to tissue. Mouthrinses containing 0.1% chlorhexidine (Chlorhexamed Fluid 0.1%) (A), 0.3% triclosan (Colgate) (B), essential oil in ethanolic solution (Listerine) (C), and amine/stannous fluoride (Meridol) (D) were tested at use concentration and in dilutions of 10, 1, and 0.1% with exposure times of 1, 10, and 30 min, respectively. The mouthrinses (test) and Ringer's solutions (control) were applied to opened rat peritoneum. After thorough irrigation with Ringer's solution, a piece of peritoneum was removed and 1 x 1 mm explants were cut. The explants were cultivated with a bovine serum culture medium in 24-well plates at 37 degrees C in a CO2 incubator (95% air, 5% CO2). After 10 days, the tissue proliferation for the explants was assessed by a stereo microscope at 10x magnification after ethanol fixing and hemalaun staining. With 24 grafts per test, the proliferation rate was calculated relative to a control, which was run for each mouthrinse and concentration/time combination. Data were analyzed using ANOVA (SPSS 11.0) and post-hoc paired t test. Statistical significance of all correlations was tested by setting the significance level at p < 0.05. At most concentrations, D caused significantly less tissue damage than A or B. There was no difference between C and A or C and B at 100%. However, the toxicity of C was significantly less than A or B at 10, 1, and 0.1%. C and D behaved similarly except for the 10% (30 min) and the 1% (10 min) solutions in which C was significantly less toxic. We concluded that the rat peritoneum explant test was demonstrated to be a sensitive test to assess the relative toxicity of mouthrinses to tissue.

Scaling and root planing and chlorhexidine mouthrinses in the treatment of chronic periodontitis: a randomized, placebo-controlled clinical trial

OBJECTIVE

Evaluation of the clinical and microbiological effects of scaling and root planing (SRP) alone or in combination with 0.12% chlorhexidine (CHX) rinsing.

METHODS

A blind, placebo-controlled, parallel-design, randomized clinical trial was conducted in 29 subjects with chronic periodontitis. Subjects were assigned to two therapeutic groups: control (SRP+placebo) and test (SRP+CHX during and up to 42 days post-therapy). Clinical and microbiological [N-benzoyl-dl-arginine-2-naphthylamide (BANA test)] examinations were performed at baseline, 42 and 63 days post-therapy.

RESULTS

Initially, intermediate sites (4-6 mm) in the test group showed less plaque accumulation, gingival bleeding, bleeding on probing and a greater reduction in attachment level and probing depth (PD) at 63 days after treatment. The initially deep sites (>6 mm) in the CHX group also showed a better reduction in plaque accumulation and in PD compared with the control group. Both therapies led to a microbiological improvement; however, the test subjects showed a higher frequency of BANA-negative sites after treatment, which was sustained over time (p<0.001). At 63 days, the control group presented 25 BANA-negative sites and 65 positive sites, and the test group 58 and 26, respectively.

CONCLUSION

The combination of CHX rinses and SRP leads to clinical benefits and to a better reduction in BANA-positive species.

Prophylactic chlorhexidine oral rinse decreases ventilator-associated pneumonia in surgical ICU patients

BACKGROUND

Pneumonia is one of the most common nosocomial infections in hospitalized patients. The risk of nosocomial pneumonia increases with age, severity of acute illness and preexisting co-morbid conditions. Ventilator-associated pneumonia (VAP) significantly increases morbidity, length of stay, resource utilization and mortality. The purpose of this study was to determine whether adherence to a ventilator weaning protocol (WP) and the use of chlorhexidine gluconate (CH) oral rinse for oral hygiene would decrease the incidence of VAP in surgical ICU patients.

METHODS

A prospective study was conducted over a period of 10 months (October 1998-July 1999) in surgical ICU patients requiring mechanical ventilation (n = 95). During the first 5 months, a WP was applied to all patients requiring mechanical ventilation. During the following 5 months, a CH 0.12% oral rinse administered twice daily was added to the protocol, initiated on ICU admission in all intubated patients. The data collection included age, gender, race, risk factors, co-morbid conditions, severity of the acute illness (APACHE II) at admission, duration of ventilation, ICU and total-hospital length of stay, and incidence of VAP and in-hospital mortality rates. Both WP and WP+CH groups were compared using the National Nosocomial Infection Surveillance (NNIS) and hospital databases as historic controls.

RESULTS

The institution of the WP alone led only to a slight decrease in the incidence of VAP but a significant reduction in the median duration of mechanical ventilation by 40% (4.5 days, p < 0.008). The addition of CH to the WP led to a significant reduction and delay in the occurrence of VAP (37% overall, 75% for late VAP, p < 0.05). The median duration of mechanical ventilation in this group was similar to that of the WP group. There was no significant difference in the overall hospital or ICU length of stay between the groups.

CONCLUSIONS

Improved oral hygiene via topical CH application in conjunction with the use of a WP is effective in reducing the incidence of VAP and the duration of mechanical ventilation in surgical ICU patients.

Amine Fluoride/Stannous Fluoride and Chlorhexidine Mouthwashes as Adjuncts to Single-Stage Dental Implants: A Comparative Study

BACKGROUND

The growing popularity of non-submerged dental implants in recent years requires a greater emphasis on microbial plaque control. Chlorhexidine (CHX), the most commonly used mouthwash in implant surgery, is sometimes associated with tooth staining and alteration in taste perception. Amine fluoride/stannous fluoride (AmF/SnF2) mouthwash has been shown to have anti-infective properties; however, it has not been tested as an adjunct anti-infective means in non-submerged dental implants. The purpose of this trial was to compare AmF/SnF2 and CHX mouthwashes as adjuncts to single-stage dental implants.

METHODS

Thirty-three patients aged 34 to 79 (mean 54.30 +/- 8.69 SD) requiring dental implants were accepted into the study. Following comprehensive periodontal therapy patients received one to three non-submerged dental implants (maxilla: 17; mandible: 45; anterior: 3, posterior: 59). After surgery patients were given analgesics and antibiotics as well as 2,400 ml of coded mouthwash bottles previously randomized between the two above mentioned formulations. Clinical and radiographic parameters were recorded at baseline and 3 and 12 months post-surgery.

RESULTS

Twelve-month survival rates were 100% and 92.9% for the AmF/SnF2 and CHX groups, respectively. Compliance was slightly higher in the AmF/SnF2 group (84.35% +/- 3.39% versus 78.15% +/- 4.59% SE) but statistically similar. There was no statistically significant difference between the AmF/SnF2 and CHX groups in staining index at 3 months (1.519 +/- 0.22 versus 1.457 +/- 0.24 SE) and patient subjective evaluation of the mouthwashes. Radiographic bone loss was 0.79 +/- 0.23 and 1 +/- 0.13 SE at 3 months and 1.06 +/- 0.13 and 1.27 +/- 0.25 at 12 months for the CHX and AmF/SnF2 groups, respectively; the difference was statistically insignificant (P = 0.388 and 0.504, respectively).

CONCLUSION

Both CHX and AmF/SnF2 mouthwashes can be used post-surgically after one-stage implant surgery.

The effect of medicated chewing gums on oral health in frail older people: a 1-year clinical trial

OBJECTIVES

To determine the effects of a medicated chewing gum on the oral health of frail older people.

DESIGN

A controlled, double-blind trial using three groups based on random allocation of residential homes.

SETTING

Sixteen residential homes in West Hertfordshire, England.

PARTICIPANTS

One hundred eleven dentate subjects aged 60 and older who completed the 12-month study.

INTERVENTION

Subjects were assigned to a chlorhexidine acetate/xylitol gum (ACHX) group, a xylitol gum (X) group, or a no-gum (N) group. Subjects in the gum groups chewed two pellets for 15 minutes twice daily for 12 months.

MEASUREMENTS

Primary outcome measures were salivary flow rate, denture debris score, prevalence of angular cheilitis, and denture stomatitis; secondary outcome measures were salivary levels of caries-associated microorganisms. A single examiner, who was blinded to group allocation, made all measurements at baseline before gum usage and at subsequent examinations after 3, 6, 9, and 12 months. Separate analyses were performed for subjects with dentures.

RESULTS

Subjects in the three groups were similar in most of their baseline characteristics. The stimulated whole saliva flow rate +/- standard deviation increased significantly for the ACHX (1.4 +/- 0.7 mL/min) and X (1.6 +/- 0.9 mL/min) groups (P <.01) over baseline (ACHX = 0.9 +/- 0.6 mL/min, X = 0.8 +/- 0.6 mL/min) and N group levels (0.6 +/- 0.9 mL/min). The levels of mutans streptococci, lactobacilli, and yeasts significantly increased (P <.05) in the X and N groups. Denture debris status was significantly lower in the ACHX and X groups than at baseline or in the N group (P <.01). The reductions of 91% and 75% in denture stomatitis and angular cheilitis prevalence, respectively, that occurred in the ACHX group were significantly greater (P <.01) than the reductions in the X group (denture stomatitis 62%, angular cheilitis 43%). Prevalence of denture stomatitis and angular cheilitis were not significantly changed in the N group.

CONCLUSION

The use of a medicated chewing gum significantly improved oral health in older occupants of residential homes. Chewing gums should be considered as a potential adjunct to other oral hygiene procedures in older subjects.

Efficacy of chlorhexidine mouthrinses with and without alcohol: a clinical study

BACKGROUND

Plaque control is the main method for preventing periodontal diseases. Chlorhexidine digluconate mouthrinse is widely recognized as helping to maintain plaque control. Most of these mouthrinses contain alcohol, making them impractical for many patients, including those with oral mucosal hypersensitivity. Mouthrinses without alcohol might cause fewer side effects, but also be less efficient. In this study, we evaluated the efficacy of a 0.12% chlorhexidine mouthrinse without alcohol against one with 11% ethanol and a placebo.

METHODS

This a double-blind, parallel group study with 96 patients who tested 3 mouthrinses containing 1) chlorhexidine digluconate 0.12% sodium fluoride 0.05%, and ethanol 11% (group 1; CHX-A); 2) the same solution without alcohol (group 2; CHX-NA); and a placebo (group 3; P). Plaque and bleeding indexes were recorded in all patients prior to treatment and at 14 and 28 days.

RESULTS

There were significant differences in plaque, gingivitis, and papilla bleeding indexes in both chlorhexidine rinses compared to placebo, but no differences between the 2 CHX products.

CONCLUSIONS

In this study, the alcohol-free rinse was as effective as one containing alcohol in controlling plaque and reducing gingival inflammation. Therefore, it would seem that its use can be recommended in all patients, but especially in patients for whom the use of alcohol is contraindicated.

The influence of a 0.2% chlorhexidine mouthrinse on plaque regrowth in orthodontic patients. A randomized prospective study. Part II: Bacteriological parameters

In a prospective plaque regrowth study focusing on oral hygiene during fixed appliance therapy 12 adolescent patients (mean age 14.1 +/- 1.5 years) were evaluated twice over 2-day test periods. In the randomized, double-blind study the influences of a 0.2% chlorhexidine mouthrinse (Corsodyl, CHX) and a commercially available dentifrice supplementing fluoride (Odol-med-3) were compared intra- and interindividually in a crossover design with regard to the bacteriological parameters. The bacteriological parameters of vital fluorescence, bacteriological counts (BC), colony forming units (CFU), plating efficiency (PE) and mutans streptococci (MS) were related to the clinically assessed indices of plaque and gingivitis. All parameters analyzed demonstrated significant differences between the control and the test (chlorhexidine) group. Where-as the values of BC, CFU, and PE progressively increased in the control group from T0 to T2, these parameters distinctly decreased in the chlorhexidine group. All values of vital flora (VF) scored around 75% in the control group compared to values of 30% in the test group. BC, CFU und PE correlated significantly. The score of mutans streptococci persisted or increased in the controls whereas mutans streptococci approached 0 in the chlorhexidine group. Until the 5th day of washout a clear-cut carry over of the chlorhexidine rinse on mutans streptococci as well as on the gingival index was evident. Since dead microorganisms remain on the tooth surface and in order to maintain oral health, chlorhexidine application might advisedly be supplemented by mechanical plaque control.

Successful medical therapy of Acanthamoeba keratitis with topical chlorhexidine and propamidine

INTRODUCTION

Following laboratory studies on new potential chemotherapy for Acanthamoeba keratitis, when chlorhexidine and propamidine provided an additive in vitro effect, a series of 12 patients with culture-proven Acanthamoeba keratitis from three UK centres was monitored during and after therapy.

METHODS

In all cases the clinical diagnosis was confirmed by amoebal culture. In some instances identification of the protozoa by direct microscopy of corneal tissue was possible. The medication was provided topically in drop form until the keratitis had resolved. In vitro sensitivity to chlorhexidine and propamidine was performed on all isolates and compared with sensitivity to a range of other drugs used for treatment of the infection.

RESULTS

In vitro drug testing confirmed that trophozoites and cysts of all 12 Acanthamoeba isolates were fully sensitive to chlorhexidine and propamidine. Therapy was satisfactory for controlling and eradicating the acanthamoebal infection in all patients. Three patients developed discrete stromal infiltration at the site of infection that resolved 1 week after commencing therapy, with or without use of steroids. Two patients developed a late inflammatory effect in the stromal scar at 6 months, which resolved with steroids. No clinical evidence of chlorhexidine toxicity was found in any patients.

CONCLUSIONS

The combination of topical chlorhexidine and propamidine was very effective for treating Acanthamoeba keratitis provided the drugs were continued for a sufficient period. No drug toxicity or resistance of Acanthamoeba isolates was observed in the 12 treated patients.

An in vitro study on the cytotoxicity of chlorhexidine digluconate to human gingival cells

Chlorhexidine digluconate is the active ingredient in mouthrinses used to prevent dental plaque and gingivitis. The in vitro cytotoxicity of chlorhexidine was evaluated with the Smulow-Glickman (S-G) gingival epithelial cell line. The potency of chlorhexidine was dependent on the length of exposure and composition of the exposure medium. The midpoint cytotoxicity values for 1-, 24-, and 72-h exposures were 0.106, 0.011, and 0.0045 mmol/L, respectively. S-G cells exposed for 2 h to chlorhexidine and then maintained for 48 h in chlorhexidine-free medium were unable to recover from the initial insult. The adverse effects of chlorhexidine on the plasma membrane were suggested by the leakage of lactic acid dehydrogenase from chlorhexidine-treated S-G cells and by the increased permeability of chlorhexidine-treated liposomes to Ca2+. The toxicity of a 24-h exposure to chlorhexidine to the S-G cells was progressively lessened as the content of fetal bovine serum (FBS) in the exposure medium was increased from 2% to 8%. The potency of a 1-h exposure to chlorhexidine was reduced in medium amended with albumin, lecithin, and heat-killed Escherichia coli. These reductions in toxicity were presumably due to the binding of the cationic chlorhexidine to the negatively charged chemical moieties of the components of FBS and of albumin and lecithin and of sites on the surfaces of bacteria. Combinations of chlorhexidine and carbamide peroxide were additive in their cytotoxicities.