Efficacy of chlorhexidine rinses after periodontal or implant surgery: a systematic review

Comparison of Chlorhexidine Gluconate, Sodium Hypochlorite, Neem Extract, and Microwave Radiation for Disinfection of Type IV Dental Stone

OBJECTIVE

 The present study evaluated the effect of chemical disinfectants and microwave sterilization on the removal of biofilm containing Pseudomonas aeruginosa, Streptococcus mutans, and Candida albicans from type IV dental stone.

MATERIALS AND METHODS

 One hundred twenty-eight (N = 128) type IV dental cast stone specimens were prepared, and biofilms of microorganisms were cultured. Dental stone samples were subjected to disinfection protocols, including 0.5% chlorhexidine (CHX), 0.5% sodium hypochlorite (NaOCl), 20% neem extract, and microwave irradiation for 1 to 5 minutes. Colony forming unit (CFU) counts and scanning electron microscopy were utilized to witness changes in the biofilm, pre- and postdisinfection/sterilization.

RESULTS

 For P. aeruginosa, significant (p < 0.05) decrease in CFU counts after 1 minute (from 233 to -215) and 2, 3, and 5 minutes (from 233 to -233) were observed after CHX treatment. After microwave radiation, a significant decrease in CFU counts was also observed after 1 minute (from 233 to -130.3), 2 minutes (from 233 to -229), and 3 and 5 minutes (from 233 to -233). For S. mutans, a significant (p < 0.05) decrease in CFU counts was observed after 1, 2, 3, and 5 minutes (from 212 to -268) after NaOCl treatment and microwave radiation (from 212 to -271 after 1 minute and from 212 to -274.3 after 2, 3, and 5 minutes). For C. albicans, significant (p < 0.05) decrease in the CFU counts (1-5 minutes) was observed after CHX exposure, while NaOCl and microwave radiation demonstrated equal disinfection potency. Neem extract was effective to disinfect the dental stone; however, it was not as potent as the other disinfectants and microwave radiation.

CONCLUSION

 It was observed that exposure to CHX, NaOCl, and microwave radiation significantly reduced the microbial CFU counts. Although the use of neem extract also significantly reduced these CFU counts, this reduction was not as much as the other three tested materials. Further research exploring other chemical disinfectants with various concentrations is recommended.

Impact of Hyaluronic Acid and Other Re-Epithelializing Agents in Periodontal Regeneration: A Molecular Perspective

This narrative review delves into the molecular mechanisms of hyaluronic acid (HA) and re-epithelializing agents in the context of periodontal regeneration. Periodontitis, characterized by chronic inflammation and the destruction of tooth-supporting tissues, presents a significant challenge in restorative dentistry. Traditional non-surgical therapies (NSPTs) sometimes fail to fully manage subgingival biofilms and could benefit from adjunctive treatments. HA, with its antibacterial, antifungal, anti-inflammatory, angiogenic, and osteoinductive properties, offers promising therapeutic potential. This review synthesizes the current literature on the bioactive effects of HA and re-epithelializing agents, such as growth factors and biomaterials, in promoting cell migration, proliferation, and extracellular matrix (ECM) synthesis. By modulating signaling pathways like the Wnt/β-catenin, TGF-β, and CD44 interaction pathways, HA enhances wound healing processes and tissue regeneration. Additionally, the role of HA in facilitating cellular crosstalk between epithelial and connective tissues is highlighted, as it impacts the inflammatory response and ECM remodeling. This review also explores the combined use of HA with growth factors and cytokines in wound healing, revealing how these agents interact synergistically to optimize periodontal regeneration. Future perspectives emphasize the need for further clinical trials to evaluate the long-term outcomes of these therapies and their potential integration into periodontal treatment paradigms.

Comparison of the Effects of Mucosa Tissue Healing with Chlorhexidine Digluconate and Choline Salicylate in Patients Wearing a Removable Prosthetic Restoration-A RCT

BACKGROUND AND OBJECTIVES

A randomized, double-blind clinical trial was conducted based on the CONSORT study protocol for randomized clinical trials (NCT06531720) to compare the effectiveness of oral mucosa healing properties of 0.2% chlorhexidine digluconate (CHX) and 8.7% choline salicylate (CHS), as well as a control group (CON) with no intervention, in patients with delivered partial removable dentures (PRDs).

MATERIALS AND METHODS

Patients (n = 27) who were enrolled in the study were healthy subjects according to the inclusion/exclusion criteria, and they received new PRDs to complement Kennedy's class III and IV deficiencies. During the process of adaptation to new prosthetic restorations, OMLs were formed and treated with one of two selected preparations, either CHX = 0.2% or CHS = 8.7%, in relation to the control group (CON). The wound surface area (WSA) (mm2) was measured on repeatable intraoral images taken in accordance with the examination protocol on the first control visit on day 1, day 3, day 7, day 10, and day 14 with the assistance of computer software.

RESULTS

There were no statistically significant differences between groups. The fastest effect of WSA complete reduction was observed in the CHX group after 7 days (WAS = 0.78, SD = 1.18) in comparison to CHS = 10 days (WAS = 0.44, SD = 0.90) and CON = 14 days (WAS = 0.22, SD = 0.67). The decrease in the WSA after 7 days of observation was 85.1% in the CHX group, 70.1% in the CHS group, and 59.2% in the CON group.

CONCLUSIONS

The WSA decreased most rapidly after 7 days of treatment with 0.2% chlorhexidine digluconate (CHX), slightly more slowly after 10 days of treatment with 8.7% choline salicylate (CHS), and relatively most slowly in the CON group, who were not treated with any topical medication after 14 days. Oral mucosa lesions (OMLs) therapy during the process of adaptation to new removable prosthetic restorations is a very important element supporting the whole process. Topical medications containing 0.2% chlorhexidine digluconate are indicated as adjunctive therapy in the process of the supportive treatment and disinfection of oral mucosa lesions. However, this does not release the dentist from liability for the careful adjustment of the removable prosthetic restoration.

Potentiality of Antibacterial Gels for the Prophylactic Coating of Hernia Repair Prosthetic Materials

Prosthetic mesh infection constitutes one of the major postsurgical complications following abdominal hernia repair. Antibacterial coatings represent a prophylactic strategy to reduce the risk of infection. This study assessed the in vitro response of two antibacterial gels made of 1% carboxymethylcellulose (CMC) functionalized with an antiseptic (chlorhexidine, CHX) or an antibiotic (rifampicin, RIF), developed for the coating of polypropylene (PP) meshes for hernia repair. Fragments of a lightweight PP mesh (1 cm2) presoaked in the unloaded or drug-loaded CMC (0.05% CHX; 0.13 mg/mL RIF) were challenged with 106 CFU/mL Staphylococcus aureus (Sa) and methicillin-resistant S. aureus (MRSA). Agar diffusion tests, sonication, turbidimetry, crystal violet staining, scanning electron microscopy and cell viability assays (fibroblasts, mesothelial cells) were performed to evaluate the response of the gels. Both compounds-especially the RIF-loaded gel-exerted a biocidal effect against gram-positive bacteria, developing wide inhibition halos, precluding adhesion to the mesh surface, and hampering bacterial survival in culture. The antibiotic gel proved innocuous, while lower viability was found in cells exposed to the antiseptic (p < 0.05). Together with their fast, affordable, convenient processing and easy application, the results suggest the potential effectiveness of these drug-loaded CMC gels in providing meshes with an antibacterial coating exhibiting great biocide performance.

New Insights Regarding the Use of Relevant Synthetic Compounds in Dentistry

Worldwide, synthetic compounds are used for both in-office and at-home dental care. They are a valuable resource for both prophylactic and curative treatments for various dental problems, such as tooth decay, periodontal diseases, and many more. They are typically preferred due to their broad range of actions and ability to produce targeted, rapid, and long-lasting effects. Using a 0.12% chlorhexidine mouthwash is capable of reducing the plaque index from 47.69% to 2.37% and the bleeding index from 32.93% to 6.28% after just 2 weeks. Mouthwash with 0.1% OCT is also highly effective, as it significantly lowered the median plaque index and salivary bacterial counts in 152 patients in 5 days compared to a control group (p < 0.0001), while also reducing the gingival index (p < 0.001). When povidone-iodine was used as an irrigant during the surgical removal of mandibular third molars in 105 patients, it resulted in notably lower pain scores after 2 days compared to a control group (4.57 ± 0.60 vs. 5.71 ± 0.45). Sodium hypochlorite is excellent for root canal disinfection, as irrigating with 1% NaOCl completely eliminated the bacteria from canals in 65% patients. A 0.05% CPC mouthwash proved effective for perioperative patient care, significantly decreasing gingival bleeding (p < 0.001) and suppressing Streptococcus levels even one week post-surgery. Lastly, a 6% H2O2 paint-on varnish and 6% H2O2 tray formulations successfully bleached the teeth of 40 patients, maintaining a noticeably whiter appearance up to the 6-month follow-up, with significant color differences from the baseline (p < 0.005). Synthetic compounds have a large research base, which also provides a greater awareness of their mechanism of action and potential adverse effects. For a better understanding of how they work, several methods and assays are performed. These are protocolary techniques through which a compound's efficacy and toxicity are established.

Antimicrobial effects of surface pre-reacted glass-ionomer (S-PRG) eluate against oral microcosm biofilm

This study investigated the antimicrobial activity of surface pre-reacted glass ionomer eluate (S-PRG) against oral microcosm biofilms collected from the oral cavity of patients. Dental biofilm samples were collected from three volunteers to form microcosm biofilms in vitro. Initially, screening tests were carried out to determine the biofilm treatment conditions with S-PRG eluate. The effects of a daily treatment for 5 min using three microcosm biofilms from different patients was then evaluated. For this, biofilms were formed on tooth enamel specimens for 120 h. Biofilms treated with 100% S-PRG for 5 min per day for 5 days showed a reduction in the number of total microorganisms, streptococci and mutans streptococci. SEM images confirmed a reduction in the biofilm after treatment. Furthermore, S-PRG also reduced lactic acid production. It was concluded that S-PRG eluate reduced the microbial load and lactic acid production in oral microcosm biofilms, reinforcing its promising use as a mouthwash agent.

Satisfaction with government recommended pre-procedural mouth rinses in the mitigation of Covid-19 in Hong Kong SAR: A triple blind randomized controlled clinical trial

OBJECTIVE

To evaluate satisfaction and acceptability with three pre-procedural mouthrinses recommended by the Government of Hong Kong Special Administrative Region (HKSAR) during the COVID-19 pandemic.

MATERIAL AND METHODS

A triple-blind parallel-arm randomised controlled clinical trial was conducted. Following eligibility assessment, participants were block-randomised to the three intervention pre-procedural mouthrinses groups: Povidone-iodine, Hydrogen Peroxide and Chlorhexidine Digluconate. Participants rinsed with one of the mouthrinses assigned prior to any dental treatment. Participants, operators and assessors were blind to the assigned mouthrinses (triple blind). Satisfaction ratings were assessed on a 10 cm visual analogue scale (VAS) and acceptability of the mouthrinses were determined.

RESULTS

Following clinical screening, 228 participants were involved in the trial. The mean overall VAS satisfaction was 7.35 (SD 1.68). There was no significant difference in VAS satisfaction ratings among the three groups (p>0.05) nor in between groups. Acceptability of the mouthrinses was high with the vast majority (89.5 %, 204) willing to use the mouthrinses again if pre-procedural mouthrinsing is required. There was no significant difference in acceptability ratings (p>0.05). There were some aspects such as taste and smell that participants commented on (on average, 24.6 %, 56), although no significant difference in prevalence of reports among groups (p>0.05).

CONCLUSIONS

There were high rates of satisfaction and acceptability of the HKSAR Government recommended pre-procedural mouthrinses for the mitigation of COVID-19 transmission in the dental setting. There was no significant difference in satisfaction and acceptability rates among the three recommended pre-procedural mouthrinses.

CLINICAL RELEVANCE

The high satisfaction and acceptability rates of the HKSAR Government recommended pre-procedural mouthrinses in the mitigation of COVID-19 in this clinical trial lends support for the HKSAR's policy on pre-procedural mouthrinses in the dental setting and this has implications for practice and policy during pandemics.

Evaluation of Folic Acid-Containing Mouthrinse and Chlorhexidine Mouthrinse as an Adjunct to Scaling and Root Planing in Patients With Periodontal Disease

BACKGROUND

Periodontal disease is a host-mediated inflammation caused due to microbial challenge. Hence, mechanisms involving the control of host-associated mediators can be a potential target. The conventional nonsurgical periodontal treatment modality includes scaling and root planing (SRP), which is often combined with adjunctive chemical plaque control agents for effective disease control. Chlorhexidine (CHX) is the most common chemical plaque control agent used. Recent research is now being focused on exploring other medicinal substitutes that may benefit control of inflammation and tissue healing. Folic acid is an important nutrient that increases the ability of oral epithelial cells to resist local irritants and inflammation if supplemented either systemically or locally.

AIM

The current study aimed to evaluate the effect of folic acid and CHX mouthwash as an adjunct to scaling and root planing for treating patients with chronic periodontitis.

METHODOLOGY

In this study, 30 patients with chronic periodontitis were included and assigned to either of the two groups: Group A (receiving folic acid-containing mouthrinse) and Group B (receiving CHX mouthrinse). Periodontal measurements, including plaque index, probing pocket depth, gingival index, and healing index, were evaluated at baseline and again four weeks after scaling and root planing.

RESULTS

Significant reduction was detected in all clinical parameters (plaque index, gingival index, probing pocket depth, healing index) for both groups (p<0.05) when evaluated from baseline to four weeks.

CONCLUSION

Both mouthrinses were effective when used as an adjunct to scaling and root planing in the treatment of periodontitis. Hence, folic acid-containing mouthrinse can be used in patients with chronic periodontitis.

Chlorhexidine digluconate mouthwash alters the oral microbial composition and affects the prevalence of antimicrobial resistance genes

Introduction

Chlorhexidine (CHX) is a commonly used antiseptic in situations of limited oral hygiene ability such as after periodontal surgery. However, CHX is also considered as a possible factor in the emergence of cross-resistance to antibiotics. The aim of this study was to analyze the changes in the oral microbiota and the prevalence of antimicrobial resistance genes (ARGs) due to CHX treatment.

Materials and methods

We analyzed the oral metagenome of 20 patients who applied a 0.2% CHX mouthwash twice daily for 4 weeks following periodontal surgical procedures. Saliva and supragingival plaque samples were examined before, directly after 4 weeks, and another 4 weeks after discontinuing the CHX treatment.

Results

Alpha-diversity decreased significantly with CHX use. The Bray-Curtis dissimilarity increased in both sample sites and mainly streptococci showed a higher relative abundance after CHX treatment. Although no significant changes of ARGs could be detected, an increase in prevalence was found for genes that encode for tetracycline efflux pumps.

Conclusion

CHX treatment appears to promote a caries-associated bacterial community and the emergence of tetracycline resistance genes. Future research should focus on CHX-related changes in the microbial community and whether the discovered tetracycline resistance genes promote resistance to CHX.

Comparative study of the effect of different exposure parameters of 635nm diode laser and toluidine blue O in eliminating Aggregatibacter actinomycetemcomitans biofilm from titanium implant surfaces

BACKGROUND

The aim of this study was to investigate the effects of antimicrobial photodynamic therapy (PDT) using 635 nm diode laser irradiation with an energy density of 6 to 30 J/cm2 and toluidine blue O (TBO) as a photosensitizer on the viability of Aggregatibacter actinomycetemcomitans attached to the surface of titanium implants.

MATERIALS AND METHODS

Titanium implants contaminated with A. actinomycetemcomitans were treated with TBO alone or in combination with different exposure parameters (light doses of 6 - 30 J/cm2 at 635 nm) and 0.2 % chlorhexidine (CHX). After treatment, colony forming units (CFUs)/ml were determined to assess PDT efficacy. The structure of the biofilm of A. actinomycetemcomitans was analyzed by field emission scanning electron microscopy (FESEM).

RESULTS

Under optimal conditions, the colony count was reduced by ∼90 %. Treatment with CHX was somewhat more effective (colony formation was reduced by ∼95 %), but this agent has adverse effects that can be avoided with PDT.

CONCLUSION

This study confirms the efficacy of PDT against A. actinomycetemcomitans depending on the light dose. Treatment with TBO + 635 nm diode laser has an effect that may be equivalent to that of CHX, but perhaps with fewer adverse effects.

Effect of Chlorhexidine and Tea Tree Oil on Reducing the Number of Oral Microorganisms

OBJECTIVES

 Thus, the aim of this study was to compare the effect of using two preoperative mouthwashes (0.12% chlorhexidine and 0.2% tea tree oil) on the number of colonies of oral microorganisms.

MATERIALS AND METHODS

 Forty participants who needed to be rehabilitated with dental implants were included in this study. They were randomly divided into two groups (chlorhexidine group and tea tree group; n = 20, each). For each group, saliva samples were collected at four different times: T0 (initially)-before using the mouthwash, T1-after 1 minute of using the mouthwash, T10-after 10 minutes of using the mouthwash, and T60-after 60 minutes of using the mouthwash. At T0 and T1, saliva samples were collected before implant placement surgery, and at T10 and T60, saliva samples were collected during surgery. In each group, one saliva sample was collected at each evaluated time point for each patient, totaling 4 saliva collections per patient. MSB agar (Mitis-Salivarius-Bacitracin) and BHI agar (Brain Heart Infusion) culture media were used in each group. Microbial colony counts were performed using a magnifying glass and recorded in CFU (colony forming units)/mL. Statistical analyses were performed using the Friedman, Mann-Whitney U and Wilcoxon tests (p < 0.05).

RESULTS

 Based on MSB agar culture medium, at T0, the number of Streptococcus mutans colonies in the chlorhexidine group was significantly higher compared with the tea tree group (p <0.05; MSB agar). The chlorhexidine group showed significantly lower CFU/mL values for Streptococcus mutans at T1, T10, and T60 compared with the tea tree group (p <0.05; MSB agar). Based on BHI agar culture medium, at T0, the chlorhexidine group showed a significantly lower value of CFU/mL compared with the tea tree group (p < 0.05; BHI agar). At T1, T10, and T60, the chlorhexidine group showed significantly lower CFU/mL values compared with the tea tree group (p <0.05; BHI agar).

CONCLUSION

 Chlorhexidine is more indicated as a preoperative mouthwash than tea tree oil, due to its significantly more effective antimicrobial action.

Silica nanoparticles containing nano-silver and chlorhexidine respond to pH to suppress biofilm acids and modulate biofilms toward a non-cariogenic composition

OBJECTIVES

Dental caries is caused by acids from biofilms. pH-sensitive nanoparticle carriers could achieve improved targeted effectiveness. The objectives of this study were to develop novel mesoporous silica nanoparticles carrying nanosilver and chlorhexidine (nMS-nAg-Chx), and investigate the inhibition of biofilms as well as the modulation of biofilm to suppress acidogenic and promote benign species for the first time.

METHODS

nMS-nAg was synthesized via a modified sol-gel method. Carboxylate group functionalized nMS-nAg (COOH-nMS-nAg) was prepared and Chx was added via electrostatic interaction. Minimal inhibitory concentration (MIC), inhibition zone, and growth curves were evaluated. Streptococcus mutans (S. mutans), Streptococcus gordonii (S. gordonii), and Streptococcus sanguinis (S. sanguinis) formed multispecies biofilms. Metabolic activity, biofilm lactic acid, exopolysaccharides (EPS), and TaqMan real-time polymerase chain reaction (RT-PCR) were tested. Biofilm structures and biomass were observed by scanning electron microscopy (SEM) and live/dead bacteria staining.

RESULTS

nMS-nAg-Chx possessed pH-responsive properties, where Chx release increased at lower pH. nMS-nAg-Chx showed good biocompatibility. nMS-nAg-Chx exhibited a strong antibacterial function, reducing biofilm metabolic activity and lactic acid as compared to control (p < 0.05, n = 6). Moreso, biofilm biomass was dramatically suppressed in nMS-nAg-Chx groups. In control group, there was an increasing trend of S. mutans proportion in the multispecies biofilm, with S. mutans reaching 89.1% at 72 h. In sharp contrast, in nMS-nAg-Chx group of 25 μg/mL, the ratio of S. mutans dropped to 43.7% and the proportion of S. gordonii and S. sanguinis increased from 19.8% and 10.9 to 69.8% and 56.3%, correspondingly.

CONCLUSION

pH-sensitive nMS-nAg-Chx had potent antibacterial effects and modulated biofilm toward a non-cariogenic tendency, decreasing the cariogenic species nearly halved and increasing the benign species approximately twofold. nMS-nAg-Chx is promising for applications in mouth rinse and endodontic irrigants, and as fillers in resins to prevent caries.

Mucoadhesive Pharmacology: Latest Clinical Technology in Antiseptic Gels

Chlorhexidine (CHX) is one of the most widely used antiseptics in the oral cavity due to its high antimicrobial potential. However, many authors have stated that the effect of CHX in nonsurgical periodontal therapy is hampered by its rapid elimination from the oral environment. The aim of this study was to determine the antibacterial efficacy of a new compound of chlorhexidine 0.20% + cymenol (CYM) 0.10% on a multispecies biofilm. For this, an in vitro study was designed using a multispecies biofilm model of Streptococcus mutans, Fusobacterium nucleatum, Prevotella intermedia, and Porphyromonas gingivalis. Quantification of the microbial viability of the biofilm was performed using 5-cyano-2,3-ditolyl tetrazolium-chloride (CTC) to calculate the percentage of survival, and the biofilms were observed using a a confocal laser scanning microscopy (CLSM). It was observed that the bactericidal activity of the CHX + cymenol bioadhesive gel was superior to that of the CHX bioadhesive gel, in addition to higher penetrability into the biofilm. Therefore, there was greater elimination of bacterial biofilm with the new compound of chlorhexidine 0.2% plus cymenol 0.1% in a bioadhesive gel form compared to the formulation with only chlorhexidine 0.2% in a bioadhesive gel form.

Effect of a gel containing green tea extract and hyaluronic acid on palate pain scores and wound healing after free gingival graft: a quasi-randomized controlled clinical trial

OBJECTIVES

The aim of this study was to evaluate the effect of a gel containing green tea extract and hyaluronic acid (HA) on pain scores and wound healing in donor sites after free gingival graft (FGG).

MATERIALS AND METHODS

Forty-two patients requiring FGG were included in three groups: (1) control group (n = 14), no material was placed in the donor area; only the clot was kept in position by sutures; (2) placebo group (n = 14), vehicle gel applied 3 times a day for 7 days; and (3) test group (n = 14), gel containing green tea extract and HA applied 3 times a day for 7 days. The wound size by clinical measurement (WS-CM) and photographic image (WS-PI), complete wound epithelialization (CWE), and palatal mucosa color were evaluated after 3 days and 1, 2, and 4 weeks postoperatively. The visual analog scale (VAS) for pain and analgesic consumption were used to assess participant's perception in the same postoperative periods.

RESULTS

A similar progressive reduction in the wound size, associated with an improvement in the color pattern, was observed in all groups (p > 0.05). No significant differences were found for CWE and pain assessment between the examined groups (p > 0.05).

CONCLUSION

The gel containing green tea extract and HA application in palatal wounds after FGG removal does not provide clinical healing benefits using this investigated protocol.

CLINICAL RELEVANCE

This is the first clinical study evaluating the effect of gel containing green tea extract and HA on the palate postoperative pain control and wound healing after FGG.

TRIAL REGISTRATION

http://clinicaltrials.gov : NCT05270161.

Dual nanocarrier of chlorhexidine and fluconazole: Physicochemical characterization and effects on microcosm biofilms and oral keratinocytes

OBJECTIVES

This study assembled and characterized a dual nanocarrier of chlorhexidine (CHX) and fluconazole (FLZ), and evaluated its antibiofilm and cytotoxic effects.

METHODS

CHX and FLZ were added to iron oxide nanoparticles (IONPs) previously coated by chitosan (CS) and characterized by physical-chemical analyses. Biofilms from human saliva supplemented with Candida species were grown (72 h) on glass discs and treated (24 h) with IONPs-CS carrying CHX (at 39, 78, or 156 µg/mL) and FLZ (at 156, 312, or 624 µg/mL) in three growing associations. IONPs and CS alone, and 156 µg/mL CHX + 624 µg/mL FLZ (CHX156-FLZ624) were tested as controls. Next, microbiological analyses were performed. The viability of human oral keratinocytes (NOKsi lineage) was also determined (MTT reduction assay). Data were submitted to ANOVA or Kruskal-Wallis, followed by Fisher's LSD or Tukey's tests (α=0.05).

RESULTS

Nanocarriers with spherical-like shape and diameter around 6 nm were assembled, without compromising the crystalline property and stability of IONPs. Nanocarrier at the highest concentrations was the most effective in reducing colony-forming units of Streptococcus mutans, Lactobacillus spp., Candida albicans, and Candida glabrata. The other carriers and CHX156-FLZ624 showed similar antibiofilm effects, and significantly reduced lactic acid production (p<0.001). Also, a dose-dependent cytotoxic effect against oral keratinocytes was observed for the dual nanocarrier. IONPs-CS-CHX-FLZ and CHX-FLZ significantly reduced keratinocyte viability at CHX and FLZ concentrations ≥7.8 and 31.25 µg/mL, respectively (p<0.05).

CONCLUSION

The nanotherapy developed outperformed the effect of the combination CHX-FLZ on microcosm biofilms, without increasing the cytotoxic effect of the antimicrobials administered.

CLINICAL SIGNIFICANCE

The dual nanocarrier is a promising topically-applied therapy for the management of oral candidiasis considering that its higher antibiofilm effects allow the use of lower concentrations of antimicrobials than those found in commercial products.

Antimicrobial activity of cleansers on the cobalt-chromium surface of removable partial denture: a systematic review

This study aimed to review systematically the literature about the antimicrobial action of evaluated cleansers on the Co-Cr alloy of RPD. The search was conducted in MEDLINE/PubMed, Scopus, Lilacs, Embase and Science Direct May, 2022. The review was performed based on PRISMA guidelines and recorded in Open Science Framework. Independent reviewers performed the search, selection, extraction, and analysis of the data. The risk of bias of the in vitro and clinical trials studies was analyzed by the Joanna Briggs Institute tool. A total of 187 articles were found and 9 were included. The cleansers that showed antimicrobial action were 2% and 5.25% sodium hypochlorite, 0.12% chlorhexidine and NitrAdine effervescent tablet. Polident, Corega Tabs effervescent tablets and 5 mg/mL chitosan solution showed intermediate effects. Propolis and green tea toothpaste were not effective. Three articles presented a high risk of bias and 6, low risk. The cleansers that showed the highest antimicrobial efficacy on Co-Cr alloy were 0.12% chlorhexidine digluconate and NitrAdine and can be safely used on RPD framework.

Supra and subgingival application of antiseptics or antibiotics during periodontal therapy

Periodontal diseases (gingivitis and periodontitis) are characterized by inflammatory processes which arise as a result of disruption of the balance in the oral ecosystem. According to the current S3 level clinical practice guidelines, therapy of patients with periodontitis involves a stepwise approach that includes the control of the patient's risk factors and the debridement of supra and subgingival biofilm. This debridement can be performed with or without the use of some adjuvant therapies, including physical or chemical agents, host modulating agents, subgingivally locally delivered antimicrobials, or systemic antimicrobials. Therefore, the main aim of this article is to review in a narrative manner the existing literature regarding the adjuvant application of local agents, either subgingivally delivered antibiotics and antiseptics or supragingivally applied rinses and dentifrices, during the different steps in periodontal therapy performed in Europe.

Chlorhexidine gel topical application ameliorates inflammatory bone loss in experimental periodontitis

OBJECTIVES

This study aimed to evaluate the impact of chlorhexidine (CHX) gel on inflammation-induced periodontal tissue destruction, osteoclastogenesis, subgingival microbiota, and on the modulation of the RANKL/OPG as well as inflammatory mediators during bone remodeling in vivo.

MATERIALS AND METHODS

Ligation- and LPS injection-induced experimental periodontitis were created to investigate the effect of topical application of CHX gel in vivo. Alveolar bone loss, osteoclast number and gingival inflammation was evaluated by micro-CT, histological, immunohistochemistry and biochemical analysis. The composition of the subgingival microbiota was characterized by 16S rRNA gene sequencing.

RESULTS

Data shows significant decreases in the alveolar bone destruction in rats from ligation-plus-CHX gel group compared to ligation group. In addition, significant decreases in the number of osteoclasts on bone surface and the protein level of receptor activator of nuclear factor κB ligand (RANKL) in gingival tissue were observed in rats from ligation-plus-CHX gel group. Moreover, data shows significantly decreased inflammatory cell infiltration and decreased expression of cyclooxygenase (COX-2) and inducible NO synthase (iNOS) in gingival tissue from ligation-plus-CHX gel group versus ligation group. Assessment of the subgingival microbiota revealed changes in rats with CHX gel application treatment.

CONCLUSION

HX gel presents protective effect on gingival tissue inflammation, osteoclastogenesis, RANKL/OPG expression, inflammatory mediators, and alveolar bone loss in vivo, which may have a translational impact on the adjunctive use in the management of inflammation-induced alveolar bone loss.

Revisiting Oral Antiseptics, Microorganism Targets and Effectiveness

A good oral health status is mostly dependent on good oral hygiene habits, which knowingly impacts systemic health. Although controversial, chemical oral antiseptics can be useful in adjunct use to mechanical dental plaque control techniques in the prevention and management of local and overall health and well-being. This review aims to revisit, gather and update evidence-based clinical indications for the use of the most popular oral antiseptics, considering different types, microorganism targets and effectiveness in order to establish updated clinical recommendations.

Hypochlorous Acid as a Potential Postsurgical Antimicrobial Agent in Periodontitis: A Randomized, Controlled, Non-Inferiority Trial

BACKGROUND

Hypochlorous acid (HOCl) is an antimicrobial agent with high affinity to Gram-negative bacteria of the subgingival biofilm. It could have an equivalent or no inferiority effect to chlorhexidine (CHX) to avoid recolonization of these microorganisms after the post-surgical period.

OBJECTIVE

The objective is to compare the reduction of plaque index (PI), gingival index (GI), pocket depth (PD), gain of clinical attachment level (CAL), and bacterial recolonization of periodontopathic microorganisms in subgingival biofilm at 7, 21, and 90 days after Open Flap Debridement (OFD) under two antimicrobial protocols: (A) HOCl 0.05% followed by HOCl 0.025% and (B) CHX 0.2%/CHX 0.12% used per 21 days without regular oral hygiene during the post-surgical period.

MATERIAL AND METHODS

A no-inferiority randomized controlled trial was carried out. Thirty-two patients were randomly divided to receive each antiplaque protocol after OFD in patients with periodontitis. Clinical indexes and bacterial recolonization were assessed using qPCR for up to 90 days. Data were analyzed using repeated measures ANOVA, mixed effects models adjusted for treatment, time, and the Chi-squared/Fisher test. A no-inferiority analysis was also performed using the Hodges-Lehmann hypothesis test for non-inferiority.

RESULTS

HOCl was not inferior to CHX in reducing PI. Both groups showed a comparable reduction of recolonization for Porphyromonas gingivalis, Tannerella forsythia, and Eubacterium nodatum. However, the HOCl protocol was non-inferior to the CHX protocol for Treponema denticola and Aggregatibacter actinomicetemcomitans.

CONCLUSIONS

HOCl improved periodontal healing. HOCl showed an impact in reducing the recolonization of periodontopathic bacteria in the postoperative period.

Evaluation of the antibacterial activity of Elsholtzia ciliate essential oil against halitosis-related Fusobacterium nucleatum and Porphyromonas gingivalis

The broad-spectrum antimicrobial activity of Elsholtzia ciliate essential oil (ECO) has been previously reported, but its effectiveness against halitosis-causing bacteria such as Fusobacterium nucleatum and Porphyromonas gingivalis is not well understood. In this study, we investigated the bacteriostatic activity of ECO against planktonic cells and biofilms of F. nucleatum and P. gingivalis, as well as its ability to inhibit bacterial metabolism and production of volatile sulfur compounds (VSCs) at sub-lethal concentrations. Our findings revealed that ECO exhibited comparable activities to chlorhexidine against these oral bacteria. Treatment with ECO significantly reduced the production of VSCs, including hydrogen sulfide, dimethyl disulfide, and methanethiol, which are major contributors to bad breath. As the major chemical components of ECO, carvacrol, p-cymene, and phellandrene, were demonstrated in vitro inhibitory effects on F. nucleatum and P. gingivalis, and their combined use showed synergistic and additive effects, suggesting that the overall activity of ECO is derived from the cumulative or synergistic effect of multiple active components. ECO was found to have a destructive effect on the bacterial cell membrane by examining the cell morphology and permeability. Furthermore, the application of ECO induced significant changes in the bacterial composition of saliva-derived biofilm, resulting in the elimination of bacterial species that contribute to halitosis, including Fusobacterium, Porphyromonas, and Prevotella. These results provide experimental evidence for the potential clinical applications of ECOs in the prevention and treatment of halitosis.

The Effectiveness of the Association of Chlorhexidine with Mechanical Treatment of Peri-Implant Mucositis

(1) Background: The aim of the study was to evaluate the benefit of combining chlorhexidine with the mechanical treatment of peri-implant mucositis. (2) Methods: Articles from 2016 to 2021 included in the PubMed and Scopus databases were analyzed, following the PICOS criteria and the randomized controlled study model that used chlorhexidine in various forms in the treatment of peri-mucositis. According to the established criteria, a limited number of studies were selected. These studies had as their criteria of evaluation for the effectiveness of chlorhexidine, plaque indices, bleeding indices and depth probing indices. Chlorhexidine has been used after mechanical debridement as a solution, with different concentrations of 0.06%/0.12%/0.2% alone or in a concentration of 0.03%, in combination with 0.05% cetylpyridinium chloride, as well as in the form of a gel with a concentration of 0.2%. (3) Results: The results were assessed to a placebo or other substances, and showed a significant reduction in the indices with a follow-up period ranging from 3 months to 1 year. (4) Conclusions: The association of chlorhexidine with the mechanical treatment of peri-implant mucositis has a role in reducing inflammation, although a complete remission was not obtained in all cases, and the results were not statistically significantly different from the use of other antiseptics.

Bactericidal Activity of Silver Nanoparticles on Oral Biofilms Related to Patients with and without Periodontal Disease

BACKGROUND AND OBJECTIVES

Periodontal disease (PD) is a multifactorial oral disease regularly caused by bacterial biofilms. Silver nanoparticles (AgNP) have offered good antimicrobial activity; moreover, there is no available scientific information related to their antimicrobial effects in biofilms from patients with PD. This study reports the bactericidal activity of AgNP against oral biofilms related to PD.

MATERIALS AND METHODS

AgNP of two average particle sizes were prepared and characterized. Sixty biofilms were collected from patients with (30 subjects) and without PD (30 subjects). Minimal inhibitory concentrations of AgNP were calculated and the distribution of bacterial species was defined by polymerase chain reaction.

RESULTS

Well-dispersed sizes of AgNP were obtained (5.4 ± 1.3 and 17.5 ± 3.4 nm) with an adequate electrical stability (-38.2 ± 5.8 and -32.6 ± 5.4 mV, respectively). AgNP showed antimicrobial activities for all oral samples; however, the smaller AgNP had significantly the most increased bactericidal effects (71.7 ± 39.1 µg/mL). The most resistant bacteria were found in biofilms from PD subjects (p < 0.05). P. gingivalis, T. denticola, and T. forsythia were present in all PD biofilms (100%).

CONCLUSIONS

The AgNP showed efficient bactericidal properties as an alternative therapy for the control or progression of PD.

Complications and treatment errors in root coverage procedures

Root coverage procedures have become very common in clinical dental practice. Even though these techniques are considered safe, the clinician may face several issues during the therapy due to their surgical nature. Some of these issues can be defined strictly as complications inherent to the procedure, whereas others are medical errors or treatment errors. This review will focus on describing treatment errors and complications that may arise during different phases of the root coverage therapeutic process and on how to prevent and manage them.

Application of Platelet-Rich Fibrin and Bone Morphogenetic Protein for Full-Mouth Implant-Based Oral Rehabilitation in a Case of Mandibular Osteoradionecrosis

Osteoradionecrosis (ORN) is a debilitating complication following radiation therapy, which in the head and neck region, occurs most frequently in the mandible. Although ORN is rare, it is complex and multifactorial and requires appropriate management. Manipulation of bone in patients with head and neck cancers before radiotherapy can cause ORN. In this report, we aim to present successful insertion of four dental implants in the interforaminal segment combined with application of platelet-rich fibrin and bone morphogenetic protein in a 60-year-old male with stable ORN in the posterior regions of the mandible.

Evaluation of biologic width re-establishment using CHU aesthetic gauges in crown lengthening cases- a clinical study

Background

Present study was performed to assess the biologic width relocation by performing aesthetic crown lengthening with the help of Chu aesthetic gauges.

Methods

The study included 192 teeth from 17 individuals, of which 64 teeth underwent crown lengthening (Treated site- TS) and 128 of which shared a proximal surface (Adjacent site -AS, Non-Adjacent site- NAS) with the surgery site. The clinical parameters Plaque index (PI), gingival index (GI), gingival margin position (PGM), relative attachment level (RAL), bone sounding (BS), biological width (BW), and probing depth (PD) were recorded. The clinical recordings were made at three different times: at baseline, 3 and 6 months post-operatively. Statistical analysis was performed using one way ANOVA and for pair wise comparisons post hoc Tukey test was used. Data was expressed in mean and standard deviations. P < 0.05 was considered statistically significant.

Results

PI and GI showed significant difference (p = 0.000*) at all time intervals. PGM and RAL were significant from baseline to 3 months, baseline to 6 months (p = 0.000*) while non-significance (p > 0.05) was recorded at 3-6 months comparison for PGM, RAL, BS, BW and PD.

Conclusion

Present study concluded that usage of Chu Aesthetic gauges help in controlled removal of soft and hard tissues, biologic width and gingival margin position got stabilized within 3 months and final prosthesis can be advised after 3 months of surgery.

Antimicrobial effect and the mechanical and surface properties of a self-disinfecting and a chlorhexidine-incorporated Type IV dental stone

STATEMENT OF PROBLEM

Stone casts are subject to contamination, but whether disinfectants incorporated into the stone are effective is unclear.

PURPOSE

The purpose of this in vitro study was to evaluate the antimicrobial activity and the mechanical and surface properties of self-disinfecting gypsum (SDG) and gypsum mixed with 2% chlorhexidine (GCHX).

MATERIAL AND METHODS

Antimicrobial action was evaluated using the diffusion-disk technique on Streptococcus aureus and Candida albicans 1 hour and 24 hours after pouring the gypsum. The groups were SDG, GCHX, a positive control (PC) of gypsum mixed with distilled water, and a negative control (NC) of filter paper disk soaked with 2% chlorhexidine; n=8. Inhibition halos were measured using the ImageJ software program and statistically analyzed using the repeated measures mixed ANOVA with time×group interaction. Compressive strength (CS) in MPa and surface roughness (SR) in μm (parameters: Ra - roughness average; and Sa - 3-dimensional (3D) arithmetic mean of the surface profile) tests were performed to characterize the specimens (evaluated groups: SDG, GCHX, and PC; n=10). CS data were analyzed by a 2-way ANOVA with time×group interaction, and SR data by a 1-way ANOVA (α=.05).

RESULTS

For S aureus, there were differences between GCHX and SDG at 1 hour and 24 hours (P<.05), but no significant differences were found for C albicans (P>.05). GCHX was better than PC, except for C albicans, and showed a reduction in CS when compared with PC and SDG (P<.05) at all time intervals. The SR of GCHX increased (Ra:1.76, Sa:2.08) when compared with PC (Ra:0.89, Sa:1.12) and SDG (Ra:1.03, Sa:1.35) (Ra: P<.004 and Sa: P<.001).

CONCLUSIONS

The antimicrobial activity of GCHX against S aureus was better than that of SDG, but neither had an effect against C albicans. As for CS and SR, GCHX presented a decrease in properties when compared with PC and SDG but was within the American Dental Association #25 specification values.

Experimentally Justified Choice of Optimal Antiseptic Solution for Hygienic Care of Oral Cavity and Dentures

INTRODUCTION: The range of antiseptic agents used in clinical practice, is rather wide. However, only single studies are devoted to comparative characteristics of their effectiveness in the conditions of the oral cavity. AIM: To choose the optimal antiseptic dental cleaner by experimental study. MATERIALS AND METHODS: An aqueous solution of Furacilin (0.02%), chlorhexidine bigluconate (0.05%), Miramistin (0.01%), cetylpyridinium chloride (0.05%), hydrogen peroxide (3%), Iodinol, Rotokan, distilled water were used as washing liquids for elimination of dental plaque. The model of the dentition was created from quartz plates with an imitation of fresh plaque. Biomaterial imitating dental plaque included two solutions: 1) a strong fresh infusion of black tea leaves, cooled to +25C; 2) oatmeal jelly with temperature from +60C to +65C. The authors method of screening dental cleaners was used, based on comparing the transparency of the laboratory model of the dentition before and after exposure to the test solution by determination with an amperemeter of strength of the electric current in the photosensor device from the oxyhemograph sensor after white light emitted by a mini-emitter passed through biological material and plates and fell on it. RESULTS: The cleaning capacity of distilled water is the lowest (p 0.050.001). Rotokan, Furacilin and Iodinol have a low cleaning capacity, and Iodinol can cause a burn of the gingival cuff in case of high reaction to it, and allergic reactions. Hydrogen peroxide has an average degree of efficiency, but it dries the oral mucosa. Chlorhexidine bigluconate has the highest cleaning effect, Miramistin and cetylpyridinium chloride are slightly inferior to it (p 0.05). By the cleaning capacity, chlorhexidine bigluconate solution is significantly superior to hydrogen peroxide (p 0.05), Iodinol (p 0.02), Furacilin (p 0.02), Rotokan (p 0.01). CONCLUSION: The described method received the patent for invention of the Russian Federation No. 2019121293. Experimental studies have shown the best cleaning effect of 0.05% solution of chlorhexidine bigluconate.

Photocrosslinkable methacrylated gelatin hydrogel as a cell-friendly injectable delivery system for chlorhexidine in regenerative endodontics

OBJECTIVES

This work sought to formulate photocrosslinkable chlorhexidine (CHX)-laden methacrylated gelatin (CHX/GelMA) hydrogels with broad spectrum of action against endodontic pathogens as a clinically viable cell-friendly disinfection therapy prior to regenerative endodontics procedures.

METHODS

CHX/GelMA hydrogel formulations were successfully synthesized using CHX concentrations between 0.12 % and 5 % w/v. Hydrogel microstructure was evaluated by scanning electron microscopy (SEM). Swelling and enzymatic degradation were assessed to determine microenvironmental effects. Compression test was performed to investigate the influence of CHX incorporation on the hydrogels' biomechanics. The antimicrobial and anti-biofilm potential of the formulated hydrogels were assessed using agar diffusion assays and a microcosms biofilm model, respectively. The cytocompatibility was evaluated by exposing stem cells from human exfoliated deciduous teeth (SHEDs) to hydrogel extracts (i.e., leachable byproducts obtained from overtime hydrogel incubation in phosphate buffer saline). The data were analyzed using One- and Two-way ANOVA and Tukey's test (α = 0.05).

RESULTS

CHX/GelMA hydrogels were effectively prepared. NMR spectroscopy confirmed the incorporation of CHX into GelMA. The addition of CHX did not change the micromorphology (pore size) nor the swelling profile (p > 0.05). CHX incorporation reduced the degradation rate of the hydrogels (p < 0.001); whereas, it contributed to increased compressive modulus (p < 0.05). Regarding the antimicrobial properties, the incorporation of CHX showed a statistically significant decrease in the number of bacteria colonies at 0.12 % and 0.5 % concentration (p < 0.001) and completely inhibited the growth of biofilm at concentration levels 1 %, 2 %, and 5 %. Meanwhile, the addition of CHX, regardless of the concentration, did not lead to cell toxicity, as cell viability values were above 70 %.

SIGNIFICANCE

The addition of CHX into GelMA showed significant antimicrobial action against the pathogens tested, even at low concentrations, with the potential to be used as a cell-friendly injectable drug delivery system for root canal disinfection prior to regenerative endodontics.

Ecological Effects of Daily Antiseptic Treatment on Microbial Composition of Saliva-Grown Microcosm Biofilms and Selection of Resistant Phenotypes

Antiseptics are widely used in dental practice and included in numerous over-the-counter oral care products. However, the effects of routine antiseptic use on microbial composition of oral biofilms and on the emergence of resistant phenotypes remain unclear. Microcosm biofilms were inoculated from saliva samples of four donors and cultured in the Amsterdam Active Attachment biofilm model for 3 days. Then, they were treated two times daily with chlorhexidine digluconate (CHX) or cetylpyridinium chloride (CPC) for a period of 7 days. Ecological changes upon these multiple antiseptic treatments were evaluated by semiconductor-based sequencing of bacterial 16S rRNA genes and identification of amplicon sequence variants (ASVs). Furthermore, culture-based approaches were used for colony-forming units (CFU) assay, identification of antiseptic-resistant phenotypes using an agar dilution method, and evaluation of their antibiotic susceptibilities. Both CHX and CPC showed only slight effects on CFU and could not inhibit biofilm growth despite the two times daily treatment for 7 days. Both antiseptics showed significant ecological effects on the microbial compositions of the surviving microbiota, whereby CHX led to enrichment of rather caries-associated saccharolytic taxa and CPC led to enrichment of rather gingivitis-associated proteolytic taxa. Antiseptic-resistant phenotypes were isolated on antiseptic-containing agar plates, which also exhibited phenotypic resistance to various antibiotics. Our results highlight the need for further research into potential detrimental effects of antiseptics on the microbial composition of oral biofilms and on the spread of antimicrobial resistance in the context of their frequent use in oral healthcare.

Early Response and Clinical Efficacy of a Mouthwash Containing Chlorhexidine, Anti Discoloration System, Polyvinylpyrrolidone/Vinyl Acetate and Sodium DNA in Periodontitis Model: A Triple-Blind Randomized Controlled Clinical Trial

Polyvinylpyrrolidone/vinyl acetate (PVP/VA) is a molecule with increased adhesion capacity, and can be associated in the bacterial plaque control with sodium DNA, a natural anti-aging molecule able to improve gingival trophism. The aim of the study is to test at two weeks the antimicrobial and antiplaque properties, subjects affected by chronic periodontitis, showed by a mouthwash containing Chlorhexidine (CHX) 0.2% with Anti Discoloration System (ADS), PVP-VA, and Sodium DNA in comparison with a placebo mouthwash. A single center randomized controlled trial was conducted on a total of fifty-four (54) subjects. In the test Group (n = 27) patients were treated by a 0.2% Chlorhexidine (CHX) mouthwash with ADS, PVP-VA, and Sodium DNA, while a placebo mouthwash was used in the control Group (B). The full mouth plaque score (FMPS), full mouth bleeding score (FMBS), and gingival index (GI) were assessed at baseline, and at 1 and 2 weeks after treatment. FMPS score recorded at baseline (V2) was 52.7 ± 9.2 in the Group Test and 58.2 ± 6.1 in the Group Control (p > 0.05). After 1 week (V3), FMPS was 13.3 ± 5.6 in the Group Test and 18.7 ± 4.3 in the Group Control (p < 0.05), while at V4 (2 weeks), FMPS was 14.2 ± 4.1 in the Group Test and 20.3 ± 5.2 in the Group Control (p < 0.05). FMBS score recorded at baseline (V2) was 46.7 ± 8.7 in the Group Test and 49.2 ± 6.2 in the Group Control (p > 0.05). After 1 week (V3), FMBS was 12.7 ± 4.2 in the test Group Test and 18.5 ± 5.9 in the control Group Control (p < 0.05), while after 2 weeks (V4), it was 13.1 ± 3.2 in the Group Test and 19.8 ± 4.9 Group Control (p < 0.05). This trial has clinically showed the efficacy of a new formulation of chlorhexidine mouthwash in reducing bacterial plaque and gingival inflammation. A significant reduction of inflammation and bleeding scores was found in periodontal patients treated by a mouthwash containing CHX 0.2% with ADS, PVP-VA, and Sodium DNA compared to those treated with a placebo mouthwash.

Phenotypic Adaptation to Antiseptics and Effects on Biofilm Formation Capacity and Antibiotic Resistance in Clinical Isolates of Early Colonizers in Dental Plaque

Despite the wide-spread use of antiseptics in dental practice and oral care products, there is little public awareness of potential risks associated with antiseptic resistance and potentially concomitant cross-resistance. Therefore, the aim of this study was to investigate potential phenotypic adaptation in 177 clinical isolates of early colonizers of dental plaque (Streptococcus, Actinomyces, Rothia and Veillonella spp.) upon repeated exposure to subinhibitory concentrations of chlorhexidine digluconate (CHX) or cetylpyridinium chloride (CPC) over 10 passages using a modified microdilution method. Stability of phenotypic adaptation was re-evaluated after culture in antiseptic-free nutrient broth for 24 or 72 h. Strains showing 8-fold minimal inhibitory concentration (MIC)-increase were further examined regarding their biofilm formation capacity, phenotypic antibiotic resistance and presence of antibiotic resistance genes (ARGs). Eight-fold MIC-increases to CHX were detected in four Streptococcus isolates. These strains mostly exhibited significantly increased biofilm formation capacity compared to their respective wild-type strains. Phenotypic antibiotic resistance was detected to tetracycline and erythromycin, consistent with the detected ARGs. In conclusion, this study shows that clinical isolates of early colonizers of dental plaque can phenotypically adapt toward antiseptics such as CHX upon repeated exposure. The underlying mechanisms at genomic and transcriptomic levels need to be investigated in future studies.

New Autonomous Water-Enabled Self-Healing Coating Material with Antibacterial-Agent-Releasing Properties

A new autonomous water-enabled self-healing coating with antibacterial-agent-releasing capability was developed for the first time by precipitating an aqueous solution of hydrogen-bonded tannic acid (TA) and polyethylene glycol (PEG) (TA: 5 mg/mL; PEG: 5 mg/mL with M_W = 100 kDa) to form a smooth, uniform coating layer with an average roughness of 0.688 nm and thickness of 22.3 μm on a polymethyl methacrylate (PMMA) substrate after 10 min of incubation. Our method is cost- and time-efficient, as the hydrophilic coating (water contact angle = 65.1°) forms rapidly, binding strongly to the PMMA substrate (adhesive energy = 83 mJ/m²), without the need for pretreatment or surface modification, and is capable of rapid self-repair (approximately 5 min) through hydrogen bonding in aqueous media. Furthermore, adding 0.5 mg/mL of chlorhexidine acetate (CHX), a commonly used antibacterial agent in dentistry, into the TA–PEG emulsion allowed the release of 2.89 μg/mL of the drug from the coating layer, which is promising for actively inhibiting the vitality and growth of bacteria around PMMA dental restorations. The use of CHX-loaded TA–PEG hydrogen-bonded complexes is highly favorable for the fabrication of an autonomous self-healing biocoating with active antibacterial-agent-releasing capability, which can be applied not only in dentistry but also in other medical fields.

Transcriptomic Stress Response in Streptococcus mutans following Treatment with a Sublethal Concentration of Chlorhexidine Digluconate

Despite the widespread use of antiseptics such as chlorhexidine digluconate (CHX) in dental practice and oral care, the risks of potential resistance toward these antimicrobial compounds in oral bacteria have only been highlighted very recently. Since the molecular mechanisms behind antiseptic resistance or adaptation are not entirely clear and the bacterial stress response has not been investigated systematically so far, the aim of the present study was to investigate the transcriptomic stress response in Streptococcus mutans after treatment with CHX using RNA sequencing (RNA-seq). Planktonic cultures of stationary-phase S. mutans were treated with a sublethal dose of CHX (125 µg/mL) for 5 min. After treatment, RNA was extracted, and RNA-seq was performed on an Illumina NextSeq 500. Differentially expressed genes were analyzed and validated by qRT-PCR. Analysis of differential gene expression following pathway analysis revealed a considerable number of genes and pathways significantly up- or downregulated in S. mutans after sublethal treatment with CHX. In summary, the expression of 404 genes was upregulated, and that of 271 genes was downregulated after sublethal CHX treatment. Analysis of differentially expressed genes and significantly regulated pathways showed regulation of genes involved in purine nucleotide synthesis, biofilm formation, transport systems and stress responses. In conclusion, the results show a transcriptomic stress response in S. mutans upon exposure to CHX and offer insight into potential mechanisms that may result in development of resistances.

Chlorhexidine in Dentistry: Pharmacology, Uses, and Adverse Effects

Objectives

The aim of this work was to review the current uses of chlorhexidine (CHX) in dentistry based on its mechanism of action, whilst highlighting the most effective protocols that render the highest clinical efficacy whilst limiting adverse drug reactions.

Methods

A literature search was conducted using the key words chlorhexidine, mechanism of action, adverse effects, and dentistry using databases in the University of Toronto library system. The titles and abstracts were read, and relevant articles were selected.

Results

A total of 1100 publications were identified, 100 were investigated, and 67 of them were used. Out of the 67 selected articles, 12 were reviews on CHX; 5 articles focussed on CHX gels; 13 focussed on CHX mouthwashes; 8 focussed on CHX products; 13 discussed adverse effects associated with CHX; 13 focussed on periodontal pathology and treatment; 6 focussed on implant periodontal and dental surgeries; 7 evaluated effects on caries; 6 looked at the mechanisms of action; and 12 focussed on the antibacterial and antimicrobial impact on the oral biome. There were multiple areas of overlap amongst the articles, and results showed that CHX provides different uses, but mainly as an adjunct to various treatments. Mouthwash was the most superior medium when used in short time spans when mechanical prophylaxis was not possible for the prevention of gingivitis and maintenance of oral hygiene. CHX products are often used in periodontics, post–oral surgical procedures, and as a prophylaxis for multiple invasive procedures with minimal adverse effects. Tooth staining was the most negative adverse effect reported by patients.

Conclusions

CHX's antimicrobial properties make it an ideal prophylactic when mechanical debridement is not possible. CHX mouthwash appears to be more effective compared to gels. Concentrations of 0.12% to 0.2% are recommended; any mouthwash with concentrations above 0.2% will unnecessarily increase the unwanted side effects. CHX is useful amongst various areas of dentistry including oral surgery, periodontics, and even general dentistry. For long-term treatments, especially in periodontitis patients (stage I-III) undergoing nonsurgical treatments, CHX chips are recommended. CHX chips are also recommended as an adjunct to implant debridement in patients with peri-implant mucositis and peri-implantitis over CHX mouthwash and gels.

Effect of Three Chlorhexidine-Based Mouthwashes on Human Gingival Fibroblasts: An In Vitro Study

Mouthwashes containing chlorhexidine (CHX) are deemed to be associated with dose-dependent side effects, including burning sensation and taste alteration. To overcome these drawbacks, mouthwashes with CHX at lower concentrations with or without adjunctive agents are proposed. The aim of this in vitro study was to investigate the effects of three CHX-based mouthwashes on human gingival fibroblasts (HGFs). After 3 days of cell culture, groups were randomly treated for 30 s, 60 s or 120 s with (a) CHX 0.05% in combination with cetylpyridnium chloride (CPC) 0.05%; (b) CHX 0.1%; (c) CHX 0.2%; or (d) NaCl as control. Cell viability, cytotoxicity and apoptosis were evaluated at 2 h, 3 days and 6 days after the exposure to the different solutions. Similar cell viability values were found among the test groups at all time points. At day 0, higher cytotoxicity was measured in the group treated with CHX 0.02%, in particular after long application time (120 s), while no significant difference was found between CHX + CPC and the control group. All the investigated mouthwashes were well tolerated by HGF cells for the tested application times. The highest cytotoxic effect was observed for CHX 0.2%; therefore, clinicians should consider limiting its usage to carefully selected clinical situations.

Silver Nanoparticles as Chlorhexidine and Metronidazole Drug Delivery Platforms: Their Potential Use in Treating Periodontitis

Purpose

Materials and Methods

Results

Conclusion

Is Antibiotic Prophylaxis Necessary before Dental Implant Procedures in Patients with Orthopaedic Prostheses? A Systematic Review

As the population ages, more and more patients with orthopaedic prostheses (OPs) require dental implant treatment. Surveys of dentists and orthopaedic surgeons show that prophylactic antibiotics (PAs) are routinely prescribed with a very high frequency in patients with OPs who are about to undergo dental procedures. The present study aims to determine the need to prescribe prophylactic antibiotic therapy in patients with OPs treated with dental implants to promote their responsible use and reduce the risk of antimicrobial resistance. An electronic search of the MEDLINE database (via PubMed), Web of Science, LILACS, Google Scholar, and OpenGrey was carried out. The criteria used were those described by the PRISMA® Statement. No study investigated the need to prescribe PAs in patients with OPs, so four studies were included on the risk of infections of OPs after dental treatments with varying degrees of invasiveness. There is no evidence to suggest a relationship between dental implant surgeries and an increased risk of OP infection; therefore, PAs in these patients are not justified. However, the recommended doses of PAs in dental implant procedures in healthy patients are the same as those recommended to avoid infections of OPs.

Effect of dental antiseptic agents on the viability of human periodontal ligament cells

•

Cell viability is key for tissue regeneration.

•

Dental antiseptics were cytotoxic in periodontal ligament cells.

•

Real-time impedimetry proved to be a non-invasive method to monitor cell viability.

Objectives

We aimed to study whether or not various dental antiseptic agents affect the viability and proliferation of human periodontal ligament cells (PDLCs).

Materials and methods

Human PDLCs were isolated from a total of 10 surgically extracted impacted third molars and were.

cultured in-vitro. The cells were exposed to commonly used dental antiseptics, including chlorhexidine, cetylpyridinium chloride, triclosan, povidone-iodine and sodium bicarbonate for ultra-short-term (10, 20, 30 sec), short-term (10, 20, 30 min) and long-term (24, 48 h) at various concentrations. Cell morphology was observed with light microscopy. Cell viability was studied with impedimetric real-time xCELLigence and resazurin-based alamarBlue® assays. We used one-way ANOVA with Tukey’s and Bonferroni test (p < 0.05) for statistical analysis.

Results

Both alamarBlue® and xCELLigence analysis results were in agreement that ultra-short-term contact with cetylpyridinium chloride ≥ 0.01 mg/ml, chlorhexidine ≥ 1 mg/ml, triclosan ≥ 1 mg/ml and povidone-iodine ≥ 1 mg/ml as well as long-term exposure to cetylpyridinium chloride ≥ 0.001 mg/ml, chlorhexidine ≥ 0.01 mg/ml, triclosan ≥ 1 mg/ml, povidone-iodine ≥ 1 mg/ml and sodium bicarbonate ≥ 10 mg/ml was able to reduce the viability of human PDLCs significantly. According to the half-maximal inhibitory concentration (IC50) the rank of cytotoxicity was cetylpyridinium chloride > chlorhexidine > triclosan > povidone-iodine > sodium bicarbonate.

Conclusions

Our findings suggest that the tested antiseptic agents were cytotoxic to human PDLCs at lower than practically applied concentrations in dental interventions.

A Pilot Study on the Degree of Tooth Staining Caused by Pollen Water and Chlorhexidine: In Vitro Study

Background:

Chlorhexidine oral rinse has been used as an adjuvant in the treatment of periodontal disease. However, there are drawbacks of using chlorhexidine i.e. tooth staining and other side effects, including allergy reaction. In light of the proven therapeutic properties of pollen water as well as its relatively cheap cost in the market, pollen water has a potential to be an effective alternative to chlorhexidine oral rinse. The aim of this study is to compare the degree of tooth staining influenced by water-based pollen mouthwash to the standard Chlorhexidine mouthwash using spectrophotometer.

Materials and Methods:

24 specimens from extracted intact human teeth were soaked into the three different solutions, Chlorhexidine, Pollen water (date palm pollen water suspension), and normal water. Color measurements were carried out by a spectrophotometer devise and recorded at 5 different time intervals. Color change (∆E), Chroma (C*) and Hue (H*) were analyzed and compared among the three solutions.

Results:

Overall mean ∆E was similar in all groups, significant difference between all time points was found only in pollen water. The change in C* was higher in pollen water as compared to other solutions. There was a subtle increase in H* in the Chlorhexidine samples after week 3. The H* values in pollen water were stable, but a sudden decrease was observed in week 6. The difference in H* among the three solutions was significant after 3 weeks.

Conclusion:

Within the limitation of our study, it can be concluded that Pollen water stained teeth to a lesser extent than did chlorhexidine. It might be beneficial to use Pollen water as mouthwash however, further investigation is needed regarding the efficacy of plaque control.

Is saltwater mouth rinse as effective as chlorhexidine following periodontal surgery?

Design Randomised prospective double-blind study.Case selection Thirty-seven chronic periodontitis patients were randomly prescribed either saltwater (n = 17) or chlorhexidine (n = 20) mouth rinse following open flap debridement. Gingival Index (GI), post-operative pain, mouth rinse satisfaction, matrix metalloproteinase activity and tasting were assessed at baseline, one week and 12 weeks.Data analysis Inter-group and intra-group comparisons were done for all the parameters recorded at different time intervals using Friedman, Wilcoxon signed-rank and Mann-Whitney U tests. P value less than 0.05 was considered statistically significant.Results There was a statistically significant decrease in GI from baseline to week 1/week 12 following surgery in both the groups. However, there was no significant difference between the groups at any time point.Conclusions Saltwater rinses are as efficient as 0.12% chlorhexidine in reducing inflammation following minimal invasive periodontal surgery. Being an inexpensive and easily accessible option, it might be considered the mouth rinse of choice during the early stages of wound healing.

Efficacy of herbal versus chlorhexidine-based mouthwashes towards oral hygiene maintenance in patients undergoing fixed orthodontic therapy: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE

The review aims to fill the gap in literature by comparing the efficacy of herbal and chlorhexidine-based mouthwashes towards oral hygiene maintenance (OHM) in patients undergoing fixed orthodontic treatment (OT).

METHODS

Indexed databases were searched electronically to include randomized controlled trials (RCTs) for data gathering. The protocol was registered in PROSPERO (CRD42020182497). Risk of bias assessment, quality of evidence investigation, and meta-analysis were performed to evaluate reported OHM related parameters at time points before and after the use of chlorhexidine (control group) and herbal mouthwashes (intervention group). With 95% confidence intervals, mean difference (MD) or standardized mean difference (SMD) were used to estimate effect size.

RESULTS

Out of eight RCTs, results from one RCT favored chlorhexidine and the results from a second RCT favored herbal mouthwashes. Results from three RCTs showed comparable effects for the respective investigated OHM related parameters. Chlorhexidine demonstrated higher antimicrobial efficacy against Streptococcus mutans (S.mutans) in two studies, and one RCT found comparable antimicrobial efficacies. Risk of bias was low in 4 studies, and moderate and high in two studies each. Quality of evidence was very low to moderate for the respective investigated parameters. Sub-group analysis for parameters colony forming units (CFU) {SMD (0.40) [95% CI (-0.22, 1.03)], gingival index (GI) {MD (0.06) [95% CI (-0.08, 0.20)]}, plaque index (PI) {SMD 0.22 [95% CI (-0.23, 0.67)]} before the use of chlorhexidine and herbal mouthwashes remained inconclusive.

CONCLUSION

The comparison between efficacy of herbal and chlorhexidine towards OHM in patients undergoing fixed OT remains debatable.

Functional screening of a human saliva metagenomic DNA reveal novel resistance genes against sodium hypochlorite and chlorhexidine

Objective

Many sections of the health care system are facing a major challenge making infectious disease problematic to treat; antimicrobial resistance (AMR). Identification and surveillance of the resistome have been highlighted as one of the strategies to overcome the problem. This study aimed to screen for AMR genes in an oral microbiota, a complex microbial system continuously exposed to antimicrobial agents commonly used in dental practice.

Materials and methods

As a significant part of the oral microbiome cannot be conventionally cultured, a functional metagenomic approach was chosen. The human oral metagenomic DNA was extracted from saliva samples collected from 50 healthy volunteers in Norway. The oral metagenomic library was then constructed by ligating partially digested oral metagenome into pSMART BAC vector and introducing into Escherichia coli. The library was screened against antimicrobials in dental practices. All resistant clones were selected and analyzed.

Results

Screening of the oral metagenomic library against different antimicrobials detected multiple clones with resistance against chlorhexidine, triclosan, erythromycin, tetracycline, and sodium hypochlorite. Bioinformatic analysis revealed both already known resistance genes, including msr, mef(A), tetAB(46), and fabK, and genes that were not previously described to confer resistance, including recA and accB conferring resistance to sodium hypochlorite and chlorhexidine, respectively.

Conclusion

Multiple clones conferring resistance to antimicrobials commonly used in dental practices were detected, containing known and novel resistant genes by functional-based metagenomics. There is a need for more studies to increase our knowledge in the field.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-02000-5.

An in-vitro comparison of four antibacterial agents with and without nicotine and their effects on human gingival fibroblasts

BACKGROUND

To compare anti-bacterial activity of 0.12% Chlorhexidine (CHX), 10% Povidone Iodine (PVD), Vega Oral Care Gel (VEGA) and Antioxidant Gel (AO) on Streptococcus mutans, Streptococcus sanguis, Fusobacterium nucleatum and Porphyromonas gingivalis with and without nicotine and to evaluate their effects on human gingival fibroblasts (HGFs).

METHODS

S. mutans, S. sanguis, P. gingivalis and F. nucleatum were incubated with serial dilutions (1/4, 1/8, 1/16, 1/32 and 1/64) of anti-bacterial agents in media (with and without nicotine). Minimum inhibitory and minimum bactericidal concentrations (MIC/MBC) were measured, and confocal microscopy was performed.  HGFs were exposed to serial dilutions (1/10, 1/100, 1/1000 and 1/10,000) of antibacterial agents with media. Water-soluble tetrazolium-1 (WST-1) assay and lactate dehydrogenase (LDH) assay were used to assess proliferation and cytotoxicity towards HGFs.

RESULTS

CHX and PVD significantly inhibited growth of all bacterial species (p<0.0001) at all dilutions. AO and VEGA inhibited growth of all bacterial species up to only the 1/4 dilution. CHX and PVD decreased HGF proliferation at 1/10 and 1/100 dilution, while AO at all dilutions (p<0.05). CHX and AO were cytotoxic at all dilutions (p<0.05). VEGA was not cytotoxic to HGFs and did not affect HGF proliferation at any dilution (p>0.05). An increased bacterial growth was seen for all species except P. gingivalis with addition of nicotine.

CONCLUSION

CHX and PVD demonstrate superior antibacterial properties, but significantly reduce HGF proliferation. AO is bacteriostatic at lower dilutions but is highly toxic to HGFs. VEGA was bacteriostatic and demonstrated no detrimental effects on HGF's. This article is protected by copyright. All rights reserved.

Effect of Pudilan Keyanning antibacterial mouthwash on dental plaque and gingival inflammation in patients during periodontal maintenance phase: study protocol for double-blind, randomised clinical trial

INTRODUCTION

Plaque control plays a critical role in the prevention and treatment of periodontitis. Antibacterial mouthwash is one of the most important tools for plaque control. Pudilan, including extracts of Scutellaria baicalensis root, Taraxacum mongolicum, Bunge corydalis herb and Isatis indigotica, was reported playing the role of anti-inflammatory and anti-bacterial. However, its effect on dental plaque and periodontal inflammation remains unknown. We aimed to assess the efficacy of Pudilan Keyanning antibacterial mouthwash which contains the active essence of Pudilan and 0.03%-0.06% cetylpyridinium chloride, as well as Pudilan active essence for plaque control and gingival anti-inflammation in patients during periodontal maintenance phase.

METHODS AND ANALYSIS

In this double-blind, randomised, placebo-controlled clinical trial, a total of 120 participants during periodontal maintenance phase will be enrolled. After supragingival scaling, they will be randomly assigned into three groups in a 1:1:1 ratio: the Pudilan Keyanning antibacterial mouthwash group, a chlorhexidine acetate mouthwash (0.12%) group or a placebo group with mouthwash containing the same components as the Pudilan Keyanning mouthwash except for Pudilan active ingredients. They will rinse with mouthwash, respectively, two times per day for 6 weeks. Clinical parameters (such as plaque index, bleeding index) and the level of volatile sulfide in the breath will be measured and analysed. The subgingival plaque will be collected and analysed microbiologically. Questionnaire feedback will be analysed.

ETHICS AND DISSEMINATION

The study protocol (V.4) was reviewed and approved by the Medical Ethical Committee of Peking University School and Hospital of Stomatology (Ethics Approval No. PKUSSIRB-201950153b). All participants signed a written consent form.

TRIAL REGISTRATION NUMBER

ChiCTR2000041253.

Effectiveness of chlorhexidine in preventing infections among patients undergoing cardiac surgeries: a meta-analysis and systematic review

Background

Although several meta-analyses reported the impact of chlorhexidine (CHX) use in patients undergoing various types of surgery, no meta-analysis summarized the overall effectiveness of CHX specifically for cardiac surgery. This meta-analysis aimed to examine the impact of CHX on infections after cardiac surgery compared with other cleansers or antiseptics.

Methods

PubMed, Embase, and the Cochrane Library were searched from inception up to October 2020 for potentially eligible studies: (1) population: patients who underwent cardiac surgery; (2) intervention or exposure: any type of CHX use in the treatment or exposed group; (3) outcome: number of patients with infections; (4) comparison: placebo or other antiseptic agents; (5) English. The primary outcome was surgical site infection (SSI).

Results

Fourteen studies were included, with 8235 and 6901 patients in the CHX and control groups. CHX was not protective against SSI (OR = 0.77, 95% CI: 0.57–1.04, P = 0.090). CHX was protective for superficial wound infection (OR = 0.42, 95% CI: 0.26–0.70, P = 0.001), but not with deep wound infection (P = 0.509). CHX was not protective against urinary tract of infection (P = 0.415) but was protective for bloodstream infection (OR = 0.36, 95% CI: 0.16–0.80, P = 0.012), nosocomial infections (OR = 0.55, 95% CI: 0.44–0.69, P < 0.001), and pneumonia (OR = 0.26, 95% CI: 0.11–0.61, P = 0.002).

Conclusions

In patients undergoing cardiac surgery, CHX does not protect against SSI, deep wound infection, and urinary tract infections but might protect against superficial SSI, bloodstream infection, nosocomial infections, and pneumonia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-01009-3.

Effect of Chlorhexidine Digluconate in Early Wound Healing of Human Gingival Tissues. A Histological, Immunohistochemical and Biomolecular Analysis

Chlorhexidine digluconate (CHX) is considered the gold standard for oral cavity antiseptic treatment. Nevertheless, several in vitro studies have reported detrimental effects in oral tissue repair. The aim of the present study was to evaluate the in vivo effect of post-surgical CHX mouth rinse on gingival tissue (G) 24 h after injury. G biopsies were obtained in three patients 24 h after surgery with the indication of post-surgical 0.12% CHX use and were compared with those obtained from the same patients without any antiseptic use. Changes in collagen production, cell proliferation, and apoptosis were examined by histological and Ki-67/P53 immunohistochemical analysis. Fibrotic markers (COL1A1, αSMA), proapoptotic protein (BAX) expression, and wound healing-related gene modulation (RAC1, SERPINE1, TIMP1) were analyzed by quantitative real-time PCR analysis. CHX was able to reduce cellular proliferation and increase collagen deposition, proapoptotic molecule and fibrotic marker expression, and myofibroblast differentiation, reduce expression of RAC1 and trigger expression of SERPINE1 and TIMP1, showing “scar wound healing response” pattern. This study assessed for the first time the in vivo effects of CHX on gingival tissue. The demonstration of a CHX-induced fibrotic transformation, leading to scar repair, supports the need for new post-surgical clinical protocols based on a strategic and personalized use of CHX.

The Effects of Three Chlorhexidine-Based Mouthwashes on Human Osteoblast-Like SaOS-2 Cells. An In Vitro Study

Several decontamination methods for removing biofilm from implant surfaces during surgical peri-implantitis treatment have been reported, including the intraoperative usage of chlorhexidine (CHX)-based antiseptics. There is a lack of information on possible adverse effects on bone healing. The study aimed to examine the impact of three CHX-based mouthwashes on osteoblast-like cells (SaOS-2) in vitro. Cells were cultured for three days in 96-well binding plates. Each well was randomly treated for either 30, 60 or 120 s with 0.05% CHX combined with 0.05% cetylpyridinium chloride (CPC), 0.1% CHX, 0.2% CHX or sterile saline (NaCl) as control. Cell viability, cytotoxicity and apoptosis were assessed at day 0, 3 and 6. Cell viability resulted in being higher in the control group at all time points. At day 0, the CHX 0.2 group showed significantly higher cytotoxicity values compared to CHX 0.1 (30 s), CHX + CPC (30 s, 60 s and 120 s) and control (60 s and 120 s), while no significant differences were identified between CHX + CPC and both CHX 0.1 and NaCl groups. All test mouthwashes were found to induce apoptosis to a lower extent compared to control. Results indicate that 0.2% CHX presented the highest cytotoxic effect. Therefore, its intraoperative use should be carefully considered.