Systemic benefits of periodontal therapy in patients with obesity and periodontitis: a systematic review.

This systematic review aimed to answer the focused question: "What are the benefits of subgingival periodontal therapy on blood hematological and biochemical index, biomarkers of inflammation and oxidative stress, quality of life, and periodontal pathogen counts in patients with obesity and periodontitis?". A systematic literature search was performed in six databases: PubMed, Embase, LILACS, Web of Science, Cochrane and SCOPUS and other sources, and a manual search was conducted as well. Inclusion criteria were randomized and non-randomized clinical trials, and before-and-after studies on patients with obesity subjected to periodontal therapy. The results were synthesized qualitatively. Risk of bias within studies was assessed using RoB 2 and ROBINS-I tools. The certainty of evidence was evaluated following the GRADE approach. Three randomized controlled trials and 15 before-and-after studies were included. Randomized controlled trials were considered to have a low risk of bias, as compared to before-and-after studies assessed as having low, serious, and critical risks of bias. Non-surgical periodontal therapy plus azithromycin, chlorhexidine, and cetylpyridinium chloride reduced blood pressure and decreased serum levels of HbA1c, hsCRP, IL-1ß, and TNF-α. Salivary resistin level also decreased in patients with obesity and periodontitis after therapy and chlorhexidine mouth rinse. Before-and-after data suggest an improvement in total cholesterol, LDL, triglycerides, insulin resistance, C3, GCF levels of TNF-α, chemerin, vaspin, omentin-1, visfatin, 8-OHdG, and periodontal pathogen counts after therapy.

MiR-132-3p suppresses peritoneal fibrosis induced by peritoneal dialysis via targeting TGF-ß1/Smad2/3 signaling pathway.

BACKGROUND: Peritoneal fibrosis (PF) is the main complication of peritoneal dialysis (PD) and the most common cause of cessation from PD. There is still no effective therapeutic approach to reserve PF. We aimed to investigate the role of miR-132-3p and underlying potential mechanisms in PF. METHODS: A total of 18 Sprague-Dawley (SD) rats were divided randomly into three groups (n = 6): (i)Control group (ii)PF group (iii)PF+Losartan group; Rats in the PF group and PF+Losartan group received daily intraperitoneal injections of 3 mg/kg chlorhexidine for 14 days, and rats in the PF+Losartan group simultaneously received daily intraperitoneal injections of 2 mg/kg losartan for 14 days. The control group was injected with saline in the same volume. Met-5A cells were treated for 24h with TGF-ß1 dissolved in recombinant buffered saline at a concentration of 10 ng/ml, meanwhile, PBS solution as a negative control. The human peritoneal solution was collected for the detection of miR-132-3p. RESULTS: In vivo, SD rats were infused with chlorhexidine to establish PF model, and we found that miR-132-3p significantly decreased and the expressions of transforming growth factor-ß1 (TGF-ß1), and Smad2/3 were up-regulated in PF. In vitro, miR-132-3p mimics suppressed TGF-ß1/Smad2/3 activity, whereas miR-132-3p inhibition activated the pathway. In human peritoneal solution, we found that the expression of miR-132-3p decreased in a time-dependent model and its effect became more pronounced with longer PD duration. CONCLUSION: MiR-132-3p ameliorated PF by suppressing TGF-ß1/Smad2/3 activity, suggesting that miR-132-3p represented a potential therapeutic approach for PF.

Comparative effectiveness of Propolis with chlorhexidine mouthwash on gingivitis - a randomized controlled clinical study.

BACKGROUND: To assess and compare the effectiveness of propolis mouthwash with chlorhexidine mouthwash in the reduction of plaque and gingivitis. METHODS: A single centre, latin-square cross-over, double masked, randomized controlled clinical trial was conducted on 45 chronic generalized gingivitis subjects who were chosen from the dental clinic of MAHSA University, Malaysia. A total of 45 subjects were randomly assigned into one of the three different groups (n = 15 each) using a computer-generated random allocation sequence: Group A Propolis mouthwash; Group B Chlorhexidine mouthwash; and Group C Placebo mouthwash. Supragingival plaque and gingival inflammation were assessed by full mouth Plaque index (PI) and gingival index (GI) at baseline and after 21 days. The study was divided into three phases, each phase lasted for 21 days separated by a washout period of 15 days in between them. Groups A, B and C were treated with 0.2% Propolis, Chlorhexidine, and Placebo mouthwash, respectively, in phase I. The study subjects were instructed to use the assigned mouthwash twice daily for 1 min for 21 days. On day 22nd, the subjects were recalled for measurement of PI and GI. After phase I, mouthwash was crossed over as dictated by the Latin square design in phase II and III. RESULTS: At baseline, intergroup comparison revealed no statistically significant difference between Groups A, B and C (p > 0.05). On day 21, one-way ANOVA revealed statistically significant difference between the three groups for PI (p < 0.001) and GI (p < 0.001). Bonferroni post-hoc test showed statistically significant difference between Propolis and Chlorhexidine mouthwash (P < 0.001), with higher reduction in the mean plaque and gingival scores in propolis group compared to chlorhexidine and placebo groups. CONCLUSIONS: Propolis mouthwash demonstrated significant improvement in gingival health and plaque reduction. Thus, it could be used as an effective herbal mouthwash alternative to chlorhexidine mouthwash. TRIAL REGISTRATION: The trial was retrospectively registered on 25/07/2019 at clinicaltrials.gov and its identifier is NCT04032548.

Anti-biofilm effectiveness of protocols for cleaning complete dentures in hospitalized patients: a randomized controlled trial.

BACKGROUND: Denture biofilm acts as a potential reservoir for respiratory pathogens, considerably increasing the risk of lung infections, specifically aspiration pneumonia, mainly 48h after hospital admission. The establishment of a straightforward, affordable, and applicable hygiene protocol in a hospital environment for the effective control of denture biofilm can be particularly useful to prevent respiratory infections or reduce the course of established lung disease. OBJECTIVES: To evaluate the anti-biofilm effectiveness of denture cleaning protocols in hospitalized patients. METHODOLOGY: The maxillary complete dentures (MCDs) of 340 hospitalized participants were randomly cleaned once using one of the following 17 protocols (n=20): brushing with distilled water, toothpaste, or neutral liquid soap (controls); immersion in chemical solutions (1% sodium hypochlorite, alkaline peroxide, 0.12% or 2% chlorhexidine digluconate), or microwave irradiation (650 W for 3 min) combined or not with brushing. Before and after the application of the protocols, the biofilm of the intaglio surface of the MCDs was evaluated using two methods: denture biofilm coverage area (%) and microbiological quantitative cultures on blood agar and Sabouraud Dextrose Agar (CFU/mL). Data were subjected to the Wilcoxon and Kruskal-Wallis tests (α=0.05). RESULTS: All 17 protocols significantly reduced the percentage area of denture biofilm and microbial and fungal load (P<0.05). The highest percentage reductions in the area of denture biofilm were observed for 1% hypochlorite solution with or without brushing and for 2% chlorhexidine solution and microwave irradiation only in association with brushing (P<0.05). The greatest reductions in microbial and fungal load were found for the groups that used solutions of 2% chlorhexidine and 1% hypochlorite and microwave irradiation, regardless of the association with brushing (P<0.05). CONCLUSIONS: A single immersion for 10 min in 1% sodium hypochlorite, even in the absence of brushing, proved to be a straightforward, rapid, low-cost, and effective protocol for cleaning the dentures of hospitalized patients.

Adsorption of an antiseptic in a functionalized fixed-bed: Analysis of breakthrough scenarios and validation of simplistic models defending a novel proposition.

BACKGROUND: Chlorhexidine gluconate (CHG) and cetrimide, which are widely used in various pharmaceutical compositions, are considered potentially hazardous compounds. This combination was largely used during and after Covid 19 pandemic for sanitization. Removal of these two compounds from pharmaceutical waste-water with commercial and functionalized activated carbon in a packed bed column is reported. METHODS: Effects of changes in bed height, flow rate, and initial concentration on the performance of the packed bed are analyzed using Yoon-Nelson, BDST and Thomas models for commercial scale-up operation. The effects of primary design parameters like bed depth and operating parameters like inflow rate and inlet concentration of influent wastewater are studied on the extent of removal of cetrimide and chlorhexidine gluconate. Granular activated carbon (GAC) is functionalized using HF and NH4OH. The extent of enhanced adsorption using the functionalized GAC is demonstrated using breakthrough curves. SIGNIFICANT FINDINGS: K. H. Chu's iconic proposition is validated. Breakthrough time (BT) increases with bed heights and it is less in the case of cetrimide as compared to chlorhexidine gluconate. This shows that cetrimide wins in the competition and occupies the pores much faster than CHG. Mostly, BT-CHG (GAC) < BT-CHG (FAC-HF) < BT-CHG (FAC-NH3) and BT-cetrimide (GAC) < BT-cetrimide (FAC-NH3) < BT-cetrimide (FAC-HF) for a particular bed height. BT-CHG(FAC-HF)BT-cetrimide(FAC-HF)

Clinical Efficacy of Chlorhexidine Gargle Combined with Recombinant Bovine Basic Fibroblast Growth Factor Gel in the Treatment of Recurrent Oral Ulcers and Its Effects on Inflammatory Factors, Immune Function, and Recurrence Rate.

PURPOSE: To examine the clinical efficacy of a chlorhexidine gargle combined with recombinant bovine basic fibroblast growth factor (rb-bFGF) gel in the treatment of recurrent oral ulcers and its effects on inflammatory factors, immune function, and recurrence rate. MATERIALS AND METHODS: Ninety-six patients with recurrent oral ulcers were randomly assigned to two groups: experimental (treatment with chlorhexidine gargle plus rb-bFGF gel) and control (treatment with chlorhexidine gargle alone) (n = 48 cases). The therapeutic efficacy, clinical improvement of symptoms, and recurrence rate within 3 months were compared between the two groups. Serum inflammatory factor and immune factor levels of patients in the two groups were measured before and after treatment. RESULTS: A statistically significantly higher total effective rate was found in patients of the experimental group (95.83%) versus the control group (81.25%) (p < 0.05). The time to onset of pain relief was shortened, the duration of pain relief was prolonged, and VAS scores for pain level were lower in the experimental than the control group (p < 0.05). Among patients in the experimental group, the number of oral ulcers and ulcer area decreased, and faster onset of pain relief and time until normal eating improved in comparison to the control group (p < 0.05). Reduced levels of IL-2, IL-6, IL-8, and TNF-α were observed in the experimental vs the control group (p < 0.05). Elevated levels of CD3+, CD4+, and NKT and reduced levels of CD8+ were found in the experimental group compared to the control group (p < 0.05). The ulcer recurrence rate of patients in the experimental group (8.33%) was notably lower in comparison to the control group (29.17%). CONCLUSION: Chlorhexidine gargle plus rb-bFGF gel can improve the clinical outcome of patients with recurrent oral ulcers. It can reduce the levels of inflammatory factors, improve immune function, and reduce the recurrence rate.

Subgingival microbial changes in Down Syndrome adults with periodontitis after chlorhexidine adjunct non-surgical therapy and monthly recalls-A 12-month case series study.

OBJECTIVES: Down Syndrome (DS) adults are at risk for periodontitis. Previous reports indicated difficulties in periodontopathogen reduction or eradication in DS individuals after periodontal treatment. This case series follows the subgingival microbial changes in adult DS individuals with periodontitis who received chlorhexidine adjunct non-surgical therapy plus 12-month recalls. METHODS: Twenty periodontitis DS participants (7 females; 25.5 ± 5.6 years of age; 3 with generalized periodontitis) partook in a study involving non-surgical mechanical periodontal therapy, twice daily chlorhexidine gel toothbrushing, chlorhexidine mouthwash, and monthly recalls. The subgingival microbiota profile was followed at baseline, 6-, and 12-months post-operation. RESULTS: Desulfobulbus, Saccharibacteria (TM7), Tannerella, and Porphyromonas were the major subgingival genera in this DS cohort. Favorable chlorhexidine adjunct non-surgical treatment outcomes were observed, with the relative abundance of Desulfobulbus sp. HMT 041, Saccharibacteria (TM7) [G-1] bacterium HMT 346 or 349, and Tannerella forsythia significantly reduced at the end of the study, but no significant reduction of Porphyromonas gingivalis or Aggregatibacter actinomycetemcomitans could be observed. Relative abundance of Desulfobulbus sp. HMT 041 and T. forsythia were also found to be significantly associated with plaque, bleeding on probing, and probing pocket depth (PPD, in mm) at a site level, while the relative abundance of Halomonas pacifica was negatively associated with PPD. CONCLUSIONS: Successful chlorhexidine adjunct non-surgical treatment with hygiene care was accompanied by a subgingival microbial shift involving certain periodontopathogenic species, except P. gingivalis and A. actinomycetemcomitans. Further investigations are required to clarify the mechanism underpinning the unchanged relative abundance of the above two pathogens despite favorable clinical responses. CLINICAL SIGNIFICANCE: DS adults face challenges achieving optimal home care or hygiene for periodontal healing and disease prevention. Chemical adjunct mechanical periodontal therapy plus regular recalls appeared promising clinically and microbiologically, with subgingival periodontopathogenic species reduction. The persistence of A. actinomycetemcomitans and P. gingivalis in subgingival niches post-treatment warrants further investigation.

Biochemical and structural characterization of chlorhexidine as an ATP-assisted inhibitor against type 1 methionyl-tRNA synthetase from Gram-positive bacteria.

Methionyl-tRNA synthetase (MetRS) catalyzes the attachment of l-methionine (l-Met) to tRNAMet to generate methionyl-tRNAMet, an essential substrate for protein translation within ribosome. Owing to its indispensable biological function and the structural discrepancies with human counterpart, bacterial MetRS is considered an ideal target for developing antibacterials. Herein, chlorhexidine (CHX) was identified as a potent binder of Staphylococcus aureus MetRS (SaMetRS) through an ATP-aided affinity screening. The co-crystal structure showed that CHX simultaneously occupies the enlarged l-Met pocket (EMP) and the auxiliary pocket (AP) of SaMetRS with its two chlorophenyl groups, while its central hexyl linker swings upwards to interact with some conserved hydrophobic residues. ATP adopts alternative conformations in the active site cavity, and forms ionic bonds and water-mediated hydrogen bonds with CHX. Consistent with this synergistic binding mode, ATP concentration-dependently enhanced the binding affinity of CHX to SaMetRS from 10.2 µM (no ATP) to 0.45 µM (1 mM ATP). While it selectively inhibited two representative type 1 MetRSs from S. aureus and Enterococcus faecalis, CHX did not show significant interactions with three tested type 2 MetRSs, including human cytoplasmic MetRS, in the enzyme inhibition and biophysical binding assays, probably due to the conformational differences between two types of MetRSs at their EMP and AP. Our findings on CHX may inspire the design of MetRS-directed antimicrobials in future.

A Randomized Controlled Trial of Povidone-Iodine Versus Chlorhexidine Gluconate With Isopropyl Alcohol for Preoperative Vaginal Antisepsis.

Many surgeons request use of 10% povidone-iodine (PI) for vaginal antisepsis; however, when PI is contraindicated, some surgeons request use of chlorhexidine gluconate (CHG) instead. The purpose of this randomized controlled trial was to determine any significant differences in self-reported symptoms associated with vaginal antisepsis with either 10% PI scrub or 4% CHG with 4% isopropyl alcohol. The control group comprised 62 participants who underwent vaginal antisepsis with the PI product, and the intervention group comprised 58 participants who underwent vaginal antisepsis with the CHG product. Participants completed surveys immediately before surgery, immediately after surgery, and 48 to 72 hours after surgery. No significant differences were found in the reported vaginal symptoms between the two groups for any survey. One participant in the intervention group reported symptoms consistent with an allergic reaction. Additional studies are needed on the use of CHG for vaginal antisepsis.

Influence of the severity of periodontal disease on the outcome of non-surgical endodontic therapy: A prospective cohort study.

OBJECTIVE: To investigate the influence of severity of periodontal disease on periapical healing after non-surgical endodontic therapy (NSET). MATERIAL AND METHODS: In this prospective study, subjects (n = 45) requiring NSET in a mandibular molar tooth with the diagnosis of pulp necrosis and asymptomatic apical periodontitis exhibiting radiographic periapical index (PAI) score ≥ 3 and concomitant endodontic periodontal lesion (CEPL) without communication were enrolled. After dividing as per the classification of Periodontal and Peri-Implant Diseases and Conditions, subjects were equally allocated into three groups. Group I- only endodontic lesion {control: healthy periodontium (n = 15)}, Group II- CEPL having stage I and II periodontitis (n = 15) and Group III- CEPL having stage III periodontitis (n = 15). Standardized two-visit NSET was performed with 2% chlorhexidine gel as an intracanal medicament. Periodontal therapy was instituted wherever required. Subjects were recalled at 6-and 12-months for clinical and radiographic assessment. Chi-square test was performed to evaluate the difference between the groups. RESULTS: At 12-month follow-up, all teeth in the three study groups were asymptomatic. On radiographic evaluation of the periapical region, healing was observed in 80%, 47% and 50% of teeth in Groups I, Group II and Group III, respectively. However, the difference was not statistically significant between the groups (p = 0.150). CONCLUSION: The severity of periodontal disease had no influence on periapical healing after NSET in teeth with concomitant endodontic periodontal lesions without communication. CLINICAL RELEVANCE: Periodontal disease has significant impact on apical periodontitis however severity of the periodontitis does not negatively impact the apical periodontitis.

Co-immobilization of Ciprofloxacin and Chlorhexidine as a Broad-Spectrum Antimicrobial Dual-Drug Coating for Poly(vinyl chloride) (PVC)-Based Endotracheal Tubes.

The endotracheal tube (ETT) affords support for intubated patients, but the increasing incidence of ventilator-associated pneumonia (VAP) is jeopardizing its application. ETT surfaces promote (poly)microbial colonization and biofilm formation, with a heavy burden for VAP. Devising safe, broad-spectrum antimicrobial materials to tackle the ETT bioburden is needful. Herein, we immobilized ciprofloxacin (CIP) and/or chlorhexidine (CHX), through polydopamine (pDA)-based functionalization, onto poly(vinyl chloride) (PVC) surfaces. These surfaces were characterized regarding physicochemical properties and challenged with single and polymicrobial cultures of VAP-relevant bacteria (Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis) and fungi (Candida albicans). The coatings imparted PVC surfaces with a homogeneous morphology, varied wettability, and low roughness. The antimicrobial immobilization via pDA chemistry was still evidenced by infrared spectroscopy. Coated surfaces exhibited sustained CIP/CHX release, retaining prolonged (10 days) activity. CIP/CHX-coated surfaces evidencing no A549 lung cell toxicity displayed better antibiofilm outcomes than CIP or CHX coatings, preventing bacterial attachment by 4.1-7.2 Log10 CFU/mL and modestly distressingC. albicans. Their antibiofilm effectiveness was endured toward polymicrobial consortia, substantially inhibiting the adhesion of the bacterial populations (up to 8 Log10 CFU/mL) within the consortia in dual- and even inP. aeruginosa/S. aureus/C. albicans triple-species biofilms while affecting fungal adhesion by 2.7 Log10 CFU/mL (dual consortia) and 1 Log10 CFU/mL (triple consortia). The potential of the dual-drug coating strategy in preventing triple-species adhesion and impairing bacterial viability was still strengthened by live/dead microscopy. The pDA-assisted CIP/CHX co-immobilization holds a safe and robust broad-spectrum antimicrobial coating strategy for PVC-ETTs, with the promise laying in reducing VAP incidence.

Antimicrobial activity of essential oils against biofilms formed in dental acrylic resin: a systematic review of in vitro studies.

This study aimed to answer the question formulated according to the PICO strategy: 'Which essential oils show antimicrobial activity against biofilms formed on dental acrylic resin?' composed by population (dental acrylic resin), intervention (application of essential oils), comparison (denture cleansers, antifungal drugs, chlorhexidine, and oral mouthwashes), and outcome (antibiofilm activity). In vitro experimental studies evaluating the activity of EOs on biofilm formed on acrylic resin were included. PRISMA guidelines were followed, and the search was performed in the PubMed, Science Direct, Embase, and Lilacs databases and in the gray literature using Google Scholar and ProQuest in December 2023. A manual search of the reference lists of the included primary studies was performed. Of the 1467 articles identified, 37 were selected for full-text reading and 12 were included. Twelve EOs were evaluated, of which 11 showed activity against Candida spp., 3 against Staphylococcus aureus, and 1 against Pseudomonas aeruginosa. The EOs of Cymbopogon citratus, Cinnamomum zeylanicum, and Cymbopogon nardus showed higher action than chlorhexidine, C. nardus higher than Listerine, C. citratus higher than nystatin, and Melaleuca alternifolia higher than fluconazole and nystatin. However, chlorhexidine was more effective than Lippia sidoides and Salvia officinalis, sodium hypochlorite was more effective than L. sidoides, nystatin was more effective than Zingiber officinale, Amphotericin B more effective than Eucalyptus globulus and M. alternifolia. In conclusion, the EOs of C. zeylanicum, C. citratus, C. nardus, and M. alternifolia showed antimicrobial activity to reduce biofilm on dental acrylic resin.

Antibacterial mouthwash alters gut microbiome, reducing nutrient absorption and fat accumulation in Western diet-fed mice.

Prolonged use of antibacterial mouthwash is linked to an increased risk of systemic disease. We aimed to investigate if disturbing the oral microbiota would impact the lower gut microbiome with functional effects in diet-induced obesity. Mice were exposed to oral chlorhexidine and fed a Western diet (WD). Food intake and weight gain were monitored, and metabolic function, blood pressure, and microbiota were analyzed. Chlorhexidine reduced the number of viable bacteria in the mouth and lowered species richness in the gut but with proportional enrichment of some bacteria linked to metabolic pathways. In mice fed a Western diet, chlorhexidine reduced weight gain, body fat, steatosis, and plasma insulin without changing caloric intake, while increasing colon triglycerides and proteins, suggesting reduced absorption of these nutrients. The mechanisms behind these effects as well as the link between the oral microbiome and small intestinal function need to be pinpointed. While the short-term effects of chlorhexidine in this model appear beneficial, potential long-term disruptions in the oral and gut microbiota and possible malabsorption should be considered.

Comparison of different concentrations of chlorhexidine-iodophor composite solution on human skin fibroblasts.

OBJECTIVE: Chlorhexidine-iodophor (CHX-IP) composite solution is a polymer of chlorhexidine and iodophor produced with new technology, for use in diabetic foot infection. However, the effect of CHX-IP on the growth activity of fibroblasts remains unknown, thus the effects of different concentrations of CHX-IP composite solution on the viability and micromorphology of human skin fibroblasts were studied in vitro cell culture in this study. METHOD: A cell viability assay was applied to calculate cell viability and an inverted fluorescence microscope was used to observe cell morphology over five days. RESULTS: The results showed that the toxic effect of CHX-IP on fibroblasts was solution concentration-dependent and decreased over time. When the concentration of CHX-IP was 5.0mg/ml, 2.5mg/ml, 0.625mg/ml, 0.15625mg/ml, 0.078125mg/ml or 0mg/ml, the difference of optical density (OD) value on different days was statistically significant (p<0.05). There were statistically significant differences in the OD value of fibroblasts among different concentrations of CHX-IP on: day 2 (F=4.809, p=0.004); day 3 (F=21.508, p<0.001); day 4 (F=63.952, p<0.001); and day 5 (F=160.407, p<0.001). In addition, a concentration of 5.0mg/ml CHX-IP resulted in a fibroblastic viability rate of 0% on day 4, when CHX-IP was diluted to 2.5mg/ml or 1.25 mg/ml, fibroblastic viability rate decreased to 0% day 5. However, when the CHX-IP was diluted to 0.15625mg/ml or 0.078125mg/ml, the fibroblastic cell viability rate increased slightly on day 5. The morphology of cells observed under microscope indirectly supported this result. CONCLUSION: The findings of this study showed that the toxic effect of CHX-IP on fibroblasts was solution concentration-dependent and decreased over time.

Combinatorial effects between aromatic plant compounds and chlorhexidine digluconate against canine otitis-related Staphylococcus spp.

The increasing prevalence of antimicrobial resistance among bacterial pathogens necessitates novel treatment strategies, particularly in veterinary medicine where otitis in dogs is very common in small animals' clinical routines. Considering this challenge, this study explores the efficacy of aromatic plant compounds (APC), including eugenol (EUG), trans-cinnamaldehyde (TC), and geraniol (GER), and their synergistic potential when combined with the antiseptic agent chlorhexidine (CLX), offering insight into alternative therapeutic approaches. The disk diffusion assay revealed differential sensitivity of Staphylococcus spp. strains to the tested compounds, with EUG and GER showing moderate inhibition zones and TC displaying considerably larger inhibition zones. Further analysis through MIC and MBC determinations suggested that EUG required the highest concentrations to inhibit and kill the bacteria, whereas TC and GER were effective at lower concentrations. Combined with CLX, all three plant-derived compounds demonstrated a significant enhancement of antibacterial activity, indicated by reduced MIC values and a predominantly synergistic interaction across the strains tested. GER was the most potent in combination with CLX, presenting the lowest mean FICi values and the highest fold reductions in MIC. This study emphasizes the APC's potential as an adjunct to conventional antimicrobial agents like CLX. The marked synergy observed, especially with GER, suggests that such combinations could be promising alternatives in managing bacterial otitis in dogs, potentially mitigating the impact of antibiotic resistance.

Detrimental Effects of Chlorhexidine on Articular Cartilage Viability, Matrix, and Mechanics.

BACKGROUND: Chlorhexidine gluconate (CHG) solution is commonly used as an antiseptic irrigation for bacterial decontamination during orthopaedic surgery. Although the chondrotoxicity of CHG on articular cartilage has been reported, the full extent of CHG-related chondrotoxicity and its effects on the extracellular matrix and mechanical properties are unknown. PURPOSE: To investigate the in vitro effects of a single 1-minute CHG exposure on the viability, biochemical content, and mechanics of native articular cartilage explants. STUDY DESIGN: Controlled laboratory study. METHODS: Articular cartilage explants (6 per group) were harvested from femoral condyles of the porcine stifle and sectioned at tidemark. Explants were bathed in CHG solution (0.05% CHG in sterile water) at varying concentrations (0% control, 0.01% CHG, and 0.05% CHG) for 1 minute, followed by complete phosphate-buffered saline wash and culture in chondrogenic medium. At 7 days after CHG exposure, cell viability, matrix content (collagen and glycosaminoglycan [GAG]), and compressive mechanical properties (creep indentation testing) were assessed. RESULTS: One-minute CHG exposure was chondrotoxic to explants, with both 0.05% CHG (2.6% ± 4.1%) and 0.01% CHG (76.3% ± 8.6%) causing a decrease in chondrocyte viability compared with controls (97.5% ± 0.6%; P < .001 for both). CHG exposure at either concentration had no significant effect on collagen content, while 0.05% CHG exposure led to a significant decrease in mean GAG per wet weight compared with the control group (2.6% ± 1.7% vs 5.2% ± 1.9%; P = .029). There was a corresponding weakening of mechanical properties in explants treated with 0.05% CHG compared with controls, with decreases in mean aggregate modulus (177.8 ± 90.1 kPa vs 280.8 ± 19.8 kPa; P < .029) and shear modulus (102.6 ± 56.5 kPa vs 167.9 ± 16.2 kPa; P < .020). CONCLUSION: One-minute exposure to CHG for articular cartilage explants led to dose-dependent decreases in chondrocyte viability, GAG content, and compressive mechanical properties. This raises concern for the risk of mechanical failure of the cartilage tissue after CHG exposure. CLINICAL RELEVANCE: Clinicians should be judicious regarding the use of CHG irrigation at these concentrations in the presence of native articular cartilage.

The dynamics of bacterial proliferation, viability, and extracellular polymeric substances in oral biofilm development.

OBJECTIVES: This study investigated the relationship between bacterial growth, viability, and extracellular polymeric substances (EPS) formation in biofilms, particularly regarding resistance development. It also examined the impact of chemical factors on the EPS matrix and bacterial proliferation in oral biofilms. METHODS: Three multi-species oral biofilms were incubated in anaerobic conditions. Three strains of Enterococcus faecalis were incubated in aerobic conditions. The incubation periods ranged from 0 h to 7 days for short-term biofilms, and from 3 to 90 days for long-term biofilms. Fluorescent labeling with carboxyfluorescein diacetate succinimidyl ester (CFSE) and flow cytometry were used to track EPS and bacterial growth. Confocal laser scanning microscopy (CLSM) assessed bacterial viability and EPS structure. Biofilms aged 7, 14, and 21 days were treated with 2 % chlorhexidine (CHX) and 1 % sodium hypochlorite (NaOCl) to evaluate their effects on EPS and bacterial proliferation. RESULTS: Short-term biofilms showed rapid bacterial proliferation and a gradual increase in EPS, maintaining stable viability. In the first two weeks, a significant rise in CFSE indicated growing maturity. From 14 to 90 days, EPS and CFSE levels stabilized. Following treatment, CHX significantly reduced bacterial proliferation, while NaOCl decreased EPS volume. CONCLUSIONS: Biofilm development involves a balance between bacterial proliferation and EPS production. The complexity of this process poses challenges in treating biofilm-associated infections, requiring strategies tailored to the biofilm's developmental stage. CLINICAL SIGNIFICANCE: For effective root canal treatment, it is imperative to focus on reducing bacterial proliferation during the early stages of oral infections. In contrast, strategies aimed at minimizing EPS production could be more beneficial for long-term management of these conditions.