Staining and calculus formation after 0.12% chlorhexidine rinses in plaque-free and plaque covered surfaces: a randomized trial

Supragingival dental biofilm profile and biofilm control during orthodontic treatment with fixed orthodontic appliance: A randomized controlled trial

OBJECTIVE

The effectiveness of supragingival dental biofilm control during orthodontic treatment and changes in the bacterial profile were analyzed.

DESIGN

Sixty-four participants aged 12-22 years (57% female) were included in the study. Participants underwent orthodontic treatment with fixed appliances and were randomly assigned to one of the three groups, which during a period of one month: (I) used chlorhexidine digluconate (CHX), (II) used high concentration of fluoride (F) gel and (III) performed standard oral hygiene. The plaque and gingivitis index, pH of biofilm and white spot lesions (WSL) were assessed. Changes of the bacteria in the biofilm were analyzed by the quantitative polymerase chain reaction RESULTS: Increase in the plaque index, pH of biofilm, and WSL was observed during orthodontic treatment with standard oral hygiene. Large interindividual variability was present, and the effects of one-month use of fluorides and CHX on clinical parameters were not significant. Despite standard hygiene the abundance of studied biofilm bacteria increased - the most Streptoccocus mutans (14.2x) and S. salivarius (3.3x), moderate Veillonella parvula (3x) and the least S. sobrinus (2.3x) and Agregatibacter actinomycetemcomitans (1.9x). The use of CHX reduced S. sobrinus (2.2x) and A. actinomycetemcomitans (1.9x). Fluoride use reduced A. actinomycetemcomitans (1.3x) and S. sobrinus (1.2x). Fluorides better controlled S. mutans than CHX.

CONCLUSION

Bacterial biomass in supragingival biofilm increased during treatment with metal orthodontic appliances, with greater increase in cariogenic bacteria than periopathogens. Fluoride controlled S. mutans, while CHX S. sobrinus and A. actinomycetemcomitans.

In Vitro Model to Evaluate the Development of Discolorations on Human Enamel Caused by Treatment with Mouth Rinses and Black Tea Considering Brushing

OBJECTIVES

 The study aimed to develop and test an in vitro model to investigate the staining potential of mouth rinses on human enamel, considering alternating intake of black tea and tooth brushing, thus mimicking the situation in the oral cavity more realistically.

MATERIALS AND METHODS

 Eight mouth rinses with six different active ingredients (benzydamine hydrochloride [BNZ], polyhexamethylene biguanide hydrochloride [PHMB], chlorhexidine digluconate [CHX], hexetidine gluconate [HEX], octenidine dihydrochloride [OCT] and octenidine dihydrochloride + 2-phenoxyethanol [OCTP]) and concentrations were tested. Sets of six halved human molar crowns were initially pretreated by soaking in artificial saliva (30 min). Afterward, the cyclic treatment was started by soaking in artificial saliva (2 min), staining with black tea (1 min), brushing with toothpaste (5 s), and soaking in the mouth rinse (30 s). Samples were rinsed with distilled water after each treatment step. The cyclic treatment was repeated 30 times, mimicking the consumer behavior after 15 days. Photographic images were taken after 0, 10, 20, and 30 cycles. Color measurements were conducted after each staining and brushing step using a VITA-Easyshade spectrophotometer to determine the difference in lightness ∆L and the total color difference ∆E.

STATISTICAL ANALYSIS

 Analysis of variance and post-hoc Tukey test (α = 0.05) were applied.

RESULTS

 The new testing model with included brushing sequences allowed to assess the staining behavior on human teeth and provided a clear differentiation between the different investigated products. In detail, up to cycle 10, ΔE values increased for all mouth rinses with each additional cycle number. However, while ΔE values continued to increase for 0.15% BNZ, 0.1% PHMB, and 0.2% CHX between treatment cycle 10 and 30, ΔE values only slightly increased after treatment with 0.08% OCTP, 0.1% OCTP, 0.1% OCT, and 0.1% HEX. After 20 and 30 cycles, significantly less staining was found for 0.08% OCTP, 0.1% OCT, 0.1% HEX as compared to 0.2% CHX, 0.15% BNZ, and 0.1% PHMB (p < 0.05). ΔE-values were significantly lower after treatment with 0.1% OCTP as compared to 0.2% CHX1 and 0.2% CHX2 (p < 0.05).

CONCLUSION

 The proposed new methodology was found to be appropriate for assessing the staining progression of mouth rinses over a simulated application period of 15 days. The model allows differentiation of products with different active ingredients and concentrations.

Topical oxygen therapy as a novel strategy to promote wound healing and control the bacteria in implantology, oral surgery and periodontology: A review

Globally, oral infections and inflammatory lesions persist as substantial public health concerns, necessitating the introduction of novel oral treatment protocols. Oral diseases are linked to various causative factors, with dental plaque/biofilm resulting from inadequate hygiene practices playing a predominant role. The strategic implementation of novel topical therapies holds promise for effectively controlling the biofilms, addressing oral infections and promoting enhanced oral wound healing. This review aims to providing a comprehensive overview of the available evidence pertaining to the potential efficacy of topical oxygen and lactoferrin-releasing biomaterials, exemplified by the blue®m formula, as novel oral care interventions within the scope of contemporary implantology, oral surgery and periodontology.

Effectiveness of Topical Oxygen Therapy in Gingivitis and Periodontitis: Clinical Case Reports and Review of the Literature

Gingivitis and periodontitis are common oral pathological conditions. Several optional adjunctive local therapies are used clinically. While antibiotics and chlorhexidine are the most common agents of choice, their long-term use is associated with several adverse effects. Some of these include staining of teeth and restorations, cellular cytotoxicity and hypersensitivity. Topical oxygen therapy has been recently introduced and could be clinically capable of inhibiting plaque bacterial biofilm growth. Available as a mouthwash, toothpaste and oral gel, this formulation comprises cellulose, glycerol and sodium peroxoborate, and releases topical oxygen in a controlled manner. Moreover, it releases topical oxygen, in a controlled manner, and lactoferrin, which are capable of antibacterial action and stimulation of bone cells, respectively. The aim of this paper is to report a case of gingivitis and another case of periodontitis, both of which were successfully treated clinically with adjunctive local oxygen therapy (blue®m). Additionally, this paper aims to review the relevant literature in terms of adjunct topical or local therapies used in the treatment of gingivitis and periodontitis, in order to understand how local therapies are helpful and to know if local oxygen therapy is a suitable clinical alternative.

Oral Care and Positioning to Prevent Ventilator-Associated Pneumonia: A Systematic Review

Introduction

Ventilator-associated pneumonia (VAP) is one of the most common nosocomial infections in critical patients. The negative impacts of VAP on patient outcomes emphasize the importance of effective preventive measures such as oral care and patient positioning. The aim of this review was to investigate the impact of oral care and positioning on the prevention of VAP among patients in the intensive care unit.

Methods

This review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search was performed. The methodological quality of included studies was appraised using Joanna Briggs Institute checklists.

Results

In total 13 studies were included, all of them were randomized controlled trials. Six out of nine studies about oral care have significant results on VAP incidence. Regarding the position, Patients positioned at a 45-degree were less likely to develop VAP than those positioned at a 30-degree and those in a supine position.

Conclusion

Although patients positioned at 45-degree angle were less likely to develop VAP than those at 30-degree, it is necessary to individualize this practice before recommending it, once there are some contraindications, such as neurocritical patients. Regarding oral care to prevent VAP, considering the current guidelines' recommendation not to use oral chlorexidine, further studies evaluating alternatives are needed.

How could mouthwashes affect the color stability and translucency of various types of monolithic zirconia? An in-vitro study

OBJECTIVES

This study aimed to evaluate the color stability and translucency of various types of monolithic zirconia after immersion in chlorhexidine and Listerine mouthwashes.

MATERIALS AND METHODS

This experimental study was performed on 36 disk-shaped specimens fabricated from low-translucent, high-translucent, and multilayered monolithic zirconia (n = 12 per group). Each group was equally divided and immersed in either 2% chlorhexidine (CHX) or Listerine mouthwash for 2 min daily over 7 days. Changes in color (ΔE) and the translucency parameter (ΔTP) were evaluated and compared. The data were analyzed with one-way ANOVA followed by Tukey's post-hoc tests (α = 0.05).

RESULTS

Chlorhexidine caused a significantly lower ΔE and a significantly higher ΔTP in multilayered zirconia compared to the low-translucency (ΔE: P = 0.0027, ΔTP: P<0.001) and the high-translucency zirconia group (ΔE: P<0.001, ΔTP: P = 0.022). Listerine caused a significantly higher ΔE in the high-translucency zirconia group compared to the multilayered zirconia group (P = 0.0165). It also resulted in a significantly higher mean ΔTP in the multilayered zirconia group compared to the low-translucency (P = 0.0003) and high-translucency zirconia groups (P = 0.019).

CONCLUSIONS

In both mouthwashes, multilayered monolithic zirconia exhibited the highest color stability among the tested materials; albeit with the most pronounced changes in translucency. Meanwhile, high-translucency monolithic zirconia was more prone to discoloration when exposed to both mouthwashes.

Anti-biofilm activity of a novel nanoemulsion containing Curcuma xanthorrhiza oil

OBJECTIVES

We aimed to solubilize Curcuma xanthorrhiza oil (CXO) using nanoemulsification and evaluate its inhibitory effects against biofilm formation.

METHODS

The components of CXO were evaluated through high-performance liquid chromatography (HPLC) analysis. Healthy human saliva was inoculated onto hydroxyapatite discs to form microcosm biofilms for four days and treated six times with each antimicrobial agent: distilled water (DW), CXO emulsion (EM), CXO nanoemulsion (NE), and positive controls (Listerine and chlorhexidine). Biofilm fluorescence imaging was performed using quantitative light-induced fluorescence, and cell viability and dry-weight measurements were obtained. We compared the bacterial cell and extracellular polysaccharide (EPS) biovolume and thickness using confocal laser scanning microscopy (CLSM).

RESULTS

HPLC analysis revealed that CXO was composed of approximately 47% xanthorrhizol. Compared with DW, NE exhibited significantly lower red fluorescence intensity and area (42% and 37%, p < 0.001 and p < 0.001, respectively), and reduced total and aciduric bacterial cell viability (7.3% and 3.9%, p < 0.001, p = 0.01, respectively). Furthermore, the bacterial cell and EPS biovolume and thickness in NE decreased by 40-80% compared to DW, similar to chlorhexidine. Conversely, EM showed a significant difference only in cell viability against total bacteria when compared with DW (p = 0.003), with EPS biovolume and thickness exhibiting higher values than DW.

CONCLUSIONS

Nanoemulsification successfully solubilized CXO and demonstrated superior anti-biofilm effects compared to the emulsion form.

CLINICAL SIGNIFICANCE

These findings suggest the potential use of NE as a novel antimicrobial agent for preventing oral diseases.

Synergistic Antibiofilm Action of Cinnamomum verum and Brazilian Green Propolis Hydroethanolic Extracts against Multidrug-Resistant Strains of Acinetobacter baumannii and Pseudomonas aeruginosa and Their Biocompatibility on Human Keratinocytes

The accumulated dental biofilm can be a source of oral bacteria that are aspirated into the lower respiratory tract causing ventilator-associated pneumonia in hospitalized patients. The aim of this study was to evaluate the synergistic antibiofilm action of the produced and phytochemically characterized extracts of Cinnamomum verum and Brazilian green propolis (BGP) hydroethanolic extracts against multidrug-resistant clinical strains of Acinetobacter baumannii and Pseudomonas aeruginosa, in addition to their biocompatibility on human keratinocyte cell lines (HaCaT). For this, High-performance liquid chromatography analysis of the plant extracts was performed; then the minimum inhibitory and minimum bactericidal concentrations of the extracts were determined; and antibiofilm activity was evaluated with MTT assay to prevent biofilm formation and to reduce the mature biofilms. The cytotoxicity of the extracts was verified using the MTT colorimetric test, evaluating the cellular enzymatic activity. The data were analyzed with one-way ANOVA and Tukey's tests as well as Kruskal-Wallis and Dunn's tests, considering a significance level of 5%. It was possible to identify the cinnamic aldehyde in C. verum and p-coumaric, caffeic, and caffeoylquinic acids as well as flavonoids such as kaempferol and kaempferide and Artepillin-C in BGP. The combined extracts were effective in preventing biofilm formation and reducing the mature biofilms of A. baumannii and P. aeruginosa. Moreover, both extracts were biocompatible in different concentrations. Therefore, C. verum and BGP hydroethanolic extracts have bactericidal and antibiofilm action against multidrug resistant strains of A. baumannii and P. aeruginosa. In addition, the combined extracts were capable of expressively inhibiting the formation of A. baumannii and P. aeruginosa biofilms (prophylactic effect) acting similarly to 0.12% chlorhexidine gluconate.

Using Antimicrobial Photodynamic Therapy with Ultrasound Devices and Bioactive Glasses as a Combined Approach for Treating Dentin Caries Lesions

Novel approaches for caries lesion removal and treatment have been proposed. This study evaluates the combined use of an experimental ultrasound, aPDT (antimicrobial photodynamic therapy) and bioactive glasses on the removal, decontamination and remineralization of dentin caries lesions. A biological model created with a duo species biofilm (Streptococcus mutans and Lactobacillus acidophilus) was used for the development of a caries-like lesion over the dentin for 7 days. Bovine dentin specimens (4 × 4 × 2 mm) were randomized according to the following caries removal techniques: bur (BUR) or ultrasound (ULT), decontamination (with or without aPDT) and remineralization materials (45S5 or F18 bioactive glasses). The following different groups were investigated: caries lesion (control); sound dentin (control); BUR; BUR + aPDT; ULT; ULT + aPDT; BUR + 45S5, BUR + F18; ULT + 45S5; ULT + F18; BUR + aPDT + 45S5; BUR + aPDT + F18; ULT + aPDT + 45S5; and ULT + aPDT + F18. Transverse microradiography (TMR), cross-sectional microhardness (CSH), FT-Raman spectroscopy and confocal microscopy (CLSM) were performed. A two-way ANOVA and Tukey's test were used (α = 0.05). (3) Results: The TMR revealed a lesion depth of 213.9 ± 49.5 μm and a mineral loss of 4929.3% vol.μm. The CSH increases as a function of depth, regardless of the group (p < 0.05). Removal with BUR (24.40-63.03 KHN) has a greater CSH than ULT (20.01-47.53 KHN; p < 0.05). aPDT did not affect the CSH (p > 0.05). No difference was observed between 45S5 or F18 (p > 0.05), but a change was observed for ULT (p > 0.05). The FT-Raman shows no differences for the phosphate (p > 0.05), but a difference is observed for the carbonate and C-H bonds. The CLSM images show that aPDT effectively inactivates residual bacteria. A combination of ULT, aPDT and bioactive glasses can be a promising minimally invasive treatment.

Antimicrobial Efficiency of Pistacia lentiscus L. Derivates against Oral Biofilm-Associated Diseases-A Narrative Review

Pistacia lentiscus L. (PlL) has been used for centuries in traditional medicine. The richness in antimicrobial biomolecules of Pll derivates can represent an alternative to chemically formulated agents used against oral infections. This review summarizes the knowledge on the antimicrobial activity of PlL essential oil (EO), extracts, and mastic resin against microorganisms being of relevance in oral biofilm-associated diseases. Results demonstrated that the potential of PlL polyphenol extracts has led to increasing scientific interest. In fact, the extracts are a significantly more effective agent than the other PlL derivates. The positive findings regarding the inhibition of periodontal pathogens and C. albicans, together with the antioxidant activity and the reduction of the inflammatory responses, suggest the use of the extracts in the prevention and/or reversal of intraoral dysbiosis. Toothpaste, mouthwashes, and local delivery devices could be effective in the clinical management of these oral diseases.

Functional liposome loaded curcumin for the treatment of Streptococcus mutans biofilm

Introduction: Plaque biofilms, mainly formed by Streptococcus mutans (S. mutans), play an important role in the occurrence and development of dental caries. Antibiotic treatment is the traditional way to control plaque. However, problems such as poor drug penetration and antibiotic resistance have encouraged the search for alternative strategies. In this paper, we hope to avoid antibiotic resistance through the antibacterial effect of curcumin, a natural plant extract with photodynamic effects, on S. mutans. However, the clinical application of curcumin is limited due to its low water solubility, poor stability, high metabolic rate, fast clearance rate, and limited bioavailability. In recent years, liposomes have become a widely used drug carrier due to their numerous advantages, such as high drug loading efficiency, high stability in the biological environment, controlled release, biocompatibility, non-toxic, and biodegradability. So, we constructed a curcumin-loaded liposome (Cur@LP) to avoid the defect of curcumin.

Methods: Cur@LP functioned with NHS can adhere to the surface of the S. mutans biofilm by condensation reaction. Liposome (LP) and Cur@LP was characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The cytotoxicity of Cur@LP was evaluated by CCK-8 assay and LDH assay. The adhesion of Cur@LP to S. mutans biofilm was observed by confocal laser scanning microscope (CLSM). The antibiofilm efficiency of Cur@LP were evaluated by crystal violet staining, CLSM, and scanning electron microscope (SEM).

Results: The mean diameter of LP and Cur@LP were 206.67 ± 8.38 nm and 312 ± 18.78 nm respectively. The ζ-potential of LP and Cur@LP were ∼−19.3 mV and ∼−20.8 mV respectively. The encapsulation efficiency of Cur@LP was (42.61 ± 2.19) %, and curcumin was rapidly released up to ±21% at 2 h. Cur@LP has negligible cytotoxicity, and can effectively adhered to the S. mutans biofilm and inhibited its growth.

Discussion: Curcumin has been widely studied in many fields such as cancer, which can be attributed to its antioxidant and anti-inflammatory effects. At present, there are few studies on the delivery of curcumin to S. mutans biofilm. In this study, we verified the adhesion and antibiofilm of Cur@LP to S. mutans biofilm. This biofilm removal strategy has the potential to be translated into the clinic.

Synergistic inhibitory activity of Glycyrrhizae Radix and Rubi Fructus extracts on biofilm formation of Streptococcus mutans

BACKGROUND

Streptococcus mutans is a bacterium that causes oral diseases. Plaque, a biofilm produced by S. mutans and other bacteria, makes it difficult to remove cariogenic oral microorganisms, including biofilm producers. Glucan synthesis by glucosyltransferase is one of the mechanisms underlying plaque formation. This study demonstrates the effectiveness of inhibiting biofilm formation by interfering with the glucosyltransferase activity of S. mutans using edible herbal medicines.

METHODS

This study investigated the inhibitory activity of Glycyrrhizae Radix extract, Rubi Fructus extract, glycyrrhizin from Glycyrrhizae Radix, and ellagic acid from Rubi Fructus against glucosyltransferase activity of S. mutans. Enzyme kinetic analysis identified the mechanism by which glycyrrhizin and ellagic acid inhibit enzyme activity.

RESULTS

The conditions for synergistically inhibiting biofilm formation by combining Glycyrrhizae Radix and Rubi Fructus extracts were identified. Biofilm formation was also synergistically inhibited by mixing their respective active constituents, glycyrrhizin and ellagic acid. Glycyrrhizin and ellagic acid inhibited glucosyltransferase via noncompetitive and uncompetitive mechanisms, respectively, indicating that they inhibit it via distinct mechanisms.

CONCLUSIONS

This study presents an effective oral hygiene method using the synergistic activity of two natural plant extracts to inhibit biofilm formation through different inhibitory mechanisms against glucosyltransferase of S. mutans.

USE OF MOUTHWASH AND DENTIFRICE CONTAINING AN ANTIMICROBIAL PHTHALOCYANINE DERIVATIVE FOR THE REDUCTION OF CLINICAL SYMPTOMS OF COVID-19: A RANDOMIZED TRIPLE-BLIND CLINICAL TRIAL

PURPOSE

This clinical trial aimed to evaluate the use of mouthwash and dentifrice containing an antimicrobial phthalocyanine derivative (APD) to reduce the clinical symptoms in patients with COVID-19.

METHODS

This randomized, triple-blind clinical trial enrolled 134 patients aged 18 years or older who underwent COVID-19 testing through the use of nasopharyngeal swab RT-qPCR in a reference center for the diagnosis of COVID-19, had no clinical contraindications to mouthwash and gargle, and had access to cell phones with communication applications. According to the use of a mouthwash and dentifrice containing antimicrobial phthalocyanine derivatives (APD), patients were randomly assigned (1:1) to the APD or non-APD (control) group. All participants were instructed to floss twice a day, brush teeth for 2 minutes 3 times a day, and gargle/rinse (5 mL) for 1 min/3 times a day for 7 days. An online questionnaire was sent to collect data on the clinical symptoms of COVID-19 3 times: T0 (baseline before using the oral hygiene products), T3 (3 days after), and T7 (7 days after). The investigators, patients, and outcome assessors were blinded to group assignment. The Mann-Whitney, Chi-Square, Fisher's exact, and Cochran's tests were used according to the nature of the variables studied, with the level of significance set at P < .05.

RESULTS

No statistically significant difference was found in the prevalence of symptoms between groups at baseline. A statistically significant reduction in clinical symptoms was found in the control group (fatigue, shortness of breath, hoarse voice, sore throat, nasal congestion, and chest pain) and APD group (cough, fatigue, shortness of breath, hyposmia/anosmia, dysgeusia, hoarse voice, sore throat, nasal congestion, chest pain, diarrhea, and irritability/confusion) during the follow-up period. There were statistically significant differences, with a higher prevalence of symptoms in the control group at T3 and T7. Dysgeusia, sore throat, and irritability/confusion were less prevalent in the APD group at T3, and shortness of breath, hyposmia/anosmia, dysgeusia, hoarse voice, sore throat, diarrhea, and irritability/confusion were more prevalent in the control group at T7.

CONCLUSIONS

Based on this methodology, the results demonstrated that the regular use of mouthwash and dentifrice-containing APD had a positive impact on the clinical symptoms, as reported by patients with COVID-19.

Evaluation of photosensitizer-containing superhydrophobic surfaces for the antibacterial treatment of periodontal biofilms

Antimicrobial photodynamic therapy (aPDT) is a promising approach to control biofilms involved in periodontal diseases. However, certain challenges, such as staining of teeth, preferential interaction of photosensitizer (PS) with Gram-positive versus Gram-negative bacteria, and insufficient oxygen in hypoxic periodontal pockets have presented barriers to its use in the clinic. To overcome these challenges, a novel superhydrophobic (SH) film that generates airborne singlet oxygen has been developed. The SH-aPDT approach isolates the PS onto a topologically rough solid SH film on which channels allow air to diffuse to the PS surface, thus ensuring sufficient oxygen supply. Upon illumination, gas phase singlet oxygen (¹O₂) is produced and diffuses from the SH surface to the underlying biofilm. The killing efficacy was assessed as a function of transmitted fluence (17.9-89.5 J/cm²) and chorin e6 loading (96-1110 nmol/cm²) by counting of colony forming units, biofilm metabolism by XTT and confocal microscopy. The decrease in viability of both Gram-positive and Gram-negative bacteria in a multi-species biofilm was found to be linearly dependent on the fluence as well as the loading of the PS up to 71.6 J/cm² when 1110 nmols/cm² of chlorin e6 was used. A > 4.6 log bacterial reduction was observed under these conditions (p < 0.05). This novel SH-aPDT approach shows promise as an effective method to disinfect multi-species bacterial biofilms associated with periodontal disease and will be evaluated in animal models in future studies.

Nanoparticles as Next-Generation Tooth-Whitening Agents: Progress and Perspectives

Whitening agents, such as hydrogen peroxide and carbamide peroxide, are currently used in clinical applications for dental esthetic and dental care. However, the free radicals generated by whitening agents cause pathological damage; therefore, their safety issues remain controversial. Furthermore, whitening agents are known to be unstable and short-lived. Since 2001, nanoparticles (NPs) have been researched for use in tooth whitening. Importantly, nanoparticles not only function as abrasives but also release reactive oxygen species and help remineralization. This review outlines the historical development of several NPs based on their whitening effects and side effects. NPs can be categorized into metals or metal oxides, ceramic particles, graphene oxide, and piezoelectric particles. Moreover, the status quo and future prospects are discussed, and recent progress in the development of NPs and their applications in various fields requiring tooth whitening is examined. This review promotes the research and development of next-generation NPs for use in tooth whitening.

Effects of bioflavonoid-containing mouth rinses on optical properties of tooth-coloured dental restorative materials

This study investigated differences in colour (ΔE₀₀) and translucency parameter (ΔTP₀₀) of nanofilled/microhybrid composites and a glass-ionomer cement following immersion in bioflavonoid (Citrox)- or chlorhexidine-based mouth rinses. Sixty disc-shaped specimens (N = 5/group) of Filtek Supreme (3M), Gradia Anterior (GC) and Fuji IX (GC) were exposed to Citrox/0.2%CHX (Perio+0.2, Curaprox), Citrox/0.09%CHX (Perio+0.09, Curaprox), 0.2%CHX (Savacol, Colgate-Palmolive) or distilled water by 2-min agitation daily for 28 days in an orbital shaker at 200 rpm at 37 °C. Colour recordings were performed using a clinical spectrophometer to obtain CIELab coordinates. General linear model, ANOVA, Tukey test (α = 0.05) and Pearson correlation test were used to analyse data. ΔE₀₀ ranged between 0.33 (Gradia_Savacol_T28) and 6.35 (Fuji_Savacol_T28) (p < 0.001). ΔTP₀₀ ranged between 0.36 (Fuji_ Perio+0.2) and 1.73 (Fuji_Savacol) (p < 0.05). Savacol resulted in higher ΔE₀₀ of Filtek and Fuji and ΔTP₀₀ of Filtek than Perio+0.09 and Perio+0.2 (p = 0.005). Perio+0.09 and Perio+0.2 resulted in higher ΔE₀₀ at T7 than T28 (p < 0.05). There was no correlation between ΔTP₀₀ and ΔE₀₀ (r = 0.445, p = 0.147). Generally, Perio+0.2 and Perio+0.09 mouth rinses produced similar or lower ΔE₀₀ and ΔTP₀₀ than Savacol. GIC Fuji showed higher ΔE₀₀ and similar or higher ΔTP₀₀ than composites Filtek and Gradia. ΔE₀₀ in all materials decreased in Perio+0.2 and Perio+0.09 over time.

Is Chlorhexidine in Dentistry an Ally or a Foe? A Narrative Review

Chlorhexidine has been one of the most effective and popular antiseptic substances used in medicine for decades. In dentistry, it has been used in endodontics, periodontology, surgery, and general dentistry. It is also widely used daily by patients in mouth rinses, gels, or toothpastes. Because of its multiple uses, we should follow all types of research reporting its potential adverse effects. This article aims to review the most up-to-date studies regarding chlorhexidine and its possible side effects, in the period of the SARS-CoV-2 pandemic, as the use of different antiseptic substances has rapidly increased.

Effect of Temperature on Tooth Staining by 0.12% Chlorhexidine Gluconate

Introduction: Natural color of dentin is affected by many variables, including anatomical variations, age, how much dentin is exposed, or how much enamel is covering the dentin. Chlorhexidine gluconate (CHX) has been observed to cause tooth staining, especially of exposed dentin. Risk factors for CHX staining include the amount of time for CHX utilization amongst others. Interestingly, the temperature of the rinse when used has been identified as a risk factor. However, no evidence of the effect of temperature is available in the literature. The purpose of this study was to determine the effect of temperature on dentin staining due to CHX exposure.

Methods: Two studies were done. The first a pilot study at room temperature to determine the time needed to establish staining solutions, a method to evaluate stain intensity, and establish the time needed to stain dentin samples in vitro. The second study exposed dentin samples on a twice daily basis to a 1 min soak in CHX at different temperatures, followed by a period in an unstimulated saliva mixed with black tea mixture. Temperatures tested were 4, 23, 37 and 50°C. Control samples were exposed to only black tea and saliva (no CHX) and tested at 23°C.

Results: The pilot study found that the combination of CHX and black tea causes dentin staining. From this data the sample size needed for the second experiment was calculated, requiring 12 samples per group. Sixty dentin samples were divided amongst 5 groups. The data from this study showed significant darkening of the dentin samples over 18 days. The 4 and 23°C CHX rinses resulted in significant staining compared to the control samples. The 37 and 50°C CHX rinses did not stain significantly more than the control samples.

Conclusions: Chlorhexidine has the ability to cause tooth staining in the presence of chromogens such as those in black tea. Significant darkening was observed at lower temperatures (4 and 23°C) over 18 days, therefore dental professionals may wish to advise gently warming the CHX rinse toward 37°C prior to use to reduce the risk of staining.

Local Oral Delivery Agents with Anti-Biofilm Properties for the Treatment of Periodontitis and Peri-Implantitis. A Narrative Review

Despite many discoveries over the past 20 years regarding the etiopathogenesis of periodontal and peri-implant diseases, as well as significant advances in our understanding of microbial biofilms, the incidence of these pathologies continues to rise. For this reason, it was clear that other strategies were needed to eliminate biofilms. In this review, the literature database was searched for studies on locally delivered synthetic agents that exhibit anti-biofilm properties and their potential use in the treatment of two important oral diseases: periodontitis and peri-implantitis.

Analysis of Chlorhexidine Modified Cement in Orthodontic Patients: A Double-Blinded, Randomized, Controlled Trial

OBJECTIVES

The aim of this study was to evaluate the microbiological and mechanical properties of glass ionomer cement (GIC) modified by chlorhexidine (CLX) for the purpose of cementing bands to the teeth of orthodontic patients.

MATERIALS AND METHODS

Ten patients, between the ages of 19 and 33 years, in the initial stage of orthodontic treatment, were randomly designated to two groups using the split-mouth design (n = 10). One group (GICEX) had bands cemented with GIC modified by CLX and a Control group (GIC), evaluated at time intervals before (T0), 3 months (T3), and 6 months (T6) after cementation. Total microbiological counts were performed, and color stability of tooth enamel, salivary pH, and the adhesive remnant index (ARI) were evaluated.

STATISTICAL ANALYSIS

The Friedman and Dunn's tests, Mann-Whitney, one-way analysis of variance, and Tukey, and paired and non-paired t-tests (p< 0.05) were used.

RESULTS

In T3, there was evidence of significant reduction in the quantity of colony forming unit (CFU) in GICEX group in comparison with the Control (p = 0.041). In T6, the quantity of CFU was similar to the quantity in T3 and significantly different to control (p = 0.045); Control group demonstrated a similar quantity of CFU between the experimental time intervals (p = 0.066). Salivary pH demonstrated significant difference only between the time intervals T0 and T6 (p = 0.022). The tooth enamel color (p = 0.366) and ARI (p = 0.343) values demonstrated no significant changes.

CONCLUSION

The incorporation of CLX into GIC demonstrated effective antibacterial action, allowed a good bond of the cement to the enamel, a high rate of survival of the bands, did not change the color of the tooth enamel, and maintained the salivary pH at physiological levels.

Does a diluted chlorhexidine-based orthodontic mouthwash cause less discoloration compared to chlorhexidine mouthwash in fixed orthodontic patients? A randomized controlled trial

OBJECTIVE

Chlorhexidine gluconate is currently the most effective oral antimicrobial agent against microorganisms, but discoloration of the teeth prevents its long-term use and can reduce patient cooperation. In this study, the effect of chlorhexidine and a diluted chlorhexidine-based, fluoride, cetylpyridinium and vitamin added mouth rinse (Orthokin) on stain index in fixed orthodontic patients was compared.

MATERIALS AND METHODS

This study was performed as a double blind randomized controlled trial on 50 patients undergoing fixed orthodontic treatment in the age group of 14-30 years. The patients were categorized as two groups of chlorhexidine and Orthokin mouth rinses and were asked to use mouthwash for eight weeks. Groups were matched according to colouring food consumption. Extrinsic staining index was assessed by modified Loben technique. Data was analysed by SPSS software. P value was set to be 0.05.

RESULTS

In the chlorhexidine group, the stain extent index and overall stain index were increased significantly at 8 weeks (P<0.001 and P=0.002, respectively). However, the increase in stain intensity index was insignificant (P=0.07). In Orthokin group, the changes in stain extent, stain intensity and overall stain were insignificant (P=0.66, P=1.000, P=0.47, respectively).

CONCLUSION

According to the results of the present study, chlorhexidine mouthwash causes more staining of teeth compared to Orthokin mouthwash. It seems that lower concentrations of chlorhexidine can be prescribed to orthodontic patients. Although these compounds are effective in sense of oral hygiene, they do not cause significant discoloration.

Denture-Soaking Solution Containing Piper betle Extract-Loaded Polymeric Micelles; Inhibition of Candida albicans, Clinical Study, and Effects on Denture Base Resin

Candida albicans is a common overgrowth in people wearing dentures. Long-term use of antifungal chemicals carries a risk of toxic side effects. This study focused on the edible Piper betle extract because of its safety. The broth dilution method was applied for antifungal determination of the ethyl acetate fractionated extract (fEA) and fEA-loaded polymeric micelles (PMF). The PMF was prepared by thin-film hydration using poloxamer 407 as a polymer base. The results found that the weight ratio of fEA to polymer is the main factor to obtain PMF system as a clear solution, nanoparticle sizes, narrow size distribution, negative zeta potential, and high entrapment efficiency. The activity of PMF against C. albicans is significantly higher than fEA alone, with a minimum fungicidal concentration of 1.5 mg/mL. PMF from 1:3 ratio of fEA to polymer is used to develop a denture-soaking solution contained 1.5 mg fEA/mL (PMFS). A clinical study on dentures of 15 volunteers demonstrated an 86.1 ± 9.2% reduction of C. albicans after soaking the dentures in PMFS daily for 14 days. Interestingly, PMFS did not change the hardness and roughness of the denture base resins. The developed PMFS may serve as a potential natural denture-soaking solution against candidiasis in denture wearers.

Effects of the Licorice Isoflavans Licoricidin and Glabridin on the Growth, Adherence Properties, and Acid Production of Streptococcus mutans, and Assessment of Their Biocompatibility

Pharmacological studies have linked a number of human health benefits with licorice due to its anticancer, anti-inflammatory, anti-oxidant, and antimicrobial properties. The aim of this study was to investigate the effects of licoricidin and glabridin, two major licorice isoflavans, on growth and virulence properties (biofilm formation, acid production, dextran production, adherence) of the cariogenic bacterium Streptococcus mutans. Moreover, the biocompatibility of these licorice compounds was assessed in an in vitro model of oral keratinocytes. We used a broth microdilution assay to show that licoricidin and glabridin exhibit a marked antibacterial activity against S. mutans. Glabridin and, to a lesser extent, licoricidin reduced the biofilm viability of S. mutans. In addition, glabridin decreased the production of dextran by S. mutans. The two licorice isoflavans attenuated the adherence of S. mutans to a saliva-coated hydroxylapatite surface, and reduced acid production from glucose. Lastly, depending on the concentrations tested, the two licorice isoflavans showed no or low toxicity toward oral keratinocytes. Within the limitations of this study, our data suggest that licoricidin and glabridin may be promising agents for controlling dental caries.

Current uses of chlorhexidine for management of oral disease: a narrative review

OBJECTIVES

Chlorhexidine (CHX) is a commonly used antiseptic mouthwash, used by dental practitioners and the public, due to its antimicrobial effects. The aim of this article was to provide a narrative review of current antimicrobial uses of CHX relevant to dentistry in the context of oral diseases, highlighting need for further studies to support its safe and appropriate use.

STUDY SELECTION, DATA AND SOURCES

Randomised controlled trials, systematic reviews and national (UK and US) guidelines were consulted where available, with search terms for each subject category entered into MEDLINE, PubMed, Google Scholar and the Cochrane database.

RESULTS

Some evidence existed to support adjunctive short-term use of CHX to manage dental plaque, and reduce clinical symptoms of gingivitis, dry socket, as well as reduce aerosolisation of bacteria. However, use must be weighed alongside the less desirable effects of CHX, including extrinsic staining of teeth, antimicrobial resistance to antiseptic agents and the rare, but fatal, allergic reactions to CHX. Conversely, evidence for the effectiveness of chlorhexidine to manage or prevent periodontitis, dental caries, necrotising periodontal diseases, peri-implantitis, and infections associated with extraction and aerosolised viruses remains less certain.

CONCLUSIONS

The use of CHX in dentistry and oral healthcare continues to be widespread and thus it is important that dental practitioners understand that, based on its differential mechanisms of action on different microbes, appropriate clinical and dental use of CHX should be oral disease specific. However, further scientific and clinical research is required before full recommendations can be made.

Chlorhexidine: An Elixir for Periodontics

Chlorhexidine is a cationic bisbiguanide with broad antibacterial activity, and wide spectrum of activity encompassing gram-positive and gram-negative bacteria, yeasts, dermatophytes and some lipophilic viruses. Its antibacterial action is due to the disruption of the bacterial cell membrane by the chlorhexidine molecules, increasing the permeability and resulting in cell lysis. Thus, chlorhexidine plays a key role in the dentistry and is used to treat or prevent periodontal disease, and has earned its eponym of the gold standard. This article reviews in detail about the mechanism of action, indications, forms and various studies related to chlorhexidine.

Spectrophotometric Analysis of Dental Enamel Staining to Antiseptic and Dietary Agents: In Vitro Study

Results

The mouthwash containing titanium dioxide (TiO₂) nanoparticles produced the greater enamel discoloration compared to that of chlorhexidine. Brushing had little effect on removal of stains induced by all mouthwashes except for dietary solutions (lemon with sodium bicarbonate and olive with laurel) and distilled water (control).

Conclusion

The results from this study show that mouthwashes containing TiO₂ nanoparticles and other antiseptic mouthwashes cause change in color of the teeth and lead to poor esthetic appearance when compared to dietary and control solutions. Thus, future in vivo studies have to be conducted to confirm these findings as in vitro studies may not provide a reliable simulation of the clinical situations.

Effects of a derivative of reutericin 6 and gassericin A on the biofilm of Streptococcus mutans in vitro and caries prevention in vivo

It is known that Streptococcus mutans (S. mutans) is the leading cariogenic pathogen. Recently, an increasing number of antimicrobial peptides (AMPs) have been brought into consideration as anti-caries agents. Here, we designed and synthesized an AMP derived from reutericin 6 and/or gassericin A, named LN-7, and explored its effect on biofilm of S. mutans UA159 in vitro and development of dental caries in vivo. Antibacterial assays showed that LN-7 was more active against S. mutans (3.2 μM) than many peptide-based agents, capable of killing other types of Streptococci in oral cavity. In addition, LN-7 presented fast killing kinetics, with more than 97% S. mutans killed within 5 min. The mechanism of the antimicrobial activity mainly lies on the disruption of bacterial membrane. Effects of LN-7 on the biofilm formation and the viability of preformed biofilm were quantified by crystal violet staining, which showed that LN-7 could effectively inhibit the biofilm accumulation of S. mutans. Moreover, the biofilm of S. mutans treated with LN-7 displayed notable changes in bacterial viability and morphology, observed by confocal laser scanning microscopy and scanning electron microscopy. In addition, topical oral treatment with LN-7 could suppress the development of dental caries in vivo, reducing the occurrence of severe dental lesion in a rodent model. These results reveal a new peptide-based agent as a topical treatment for dental caries, opening the door to clinical studies to explore its potential for caries prevention.

A randomized double-blind clinical trial to evaluate the efficacy of chlorhexidine, antioxidant, and hyaluronic acid mouthwashes in the management of biofilm-induced gingivitis

OBJECTIVES

To investigate the antiplaque and antigingivitis efficacy in addition to evaluating side effects and subjects' perceptions of three commercially available mouthwashes.

METHODS

This study was a double-blind, parallel, and short-term trial. A total of 75 dental students with biofilm-induced gingivitis were included in the final analysis of the current study. Clinical parameters (plaque index and bleeding on probing) and the staining effect were measured at baseline and after 7 days. In addition, a VAS-based assessment questionnaire was completed by the participants.

RESULTS

All interventions significantly reduced plaque scores, but chlorhexidine (CHX) had a significantly higher effect than the hyaluronic acid (HA) and antioxidant mouthwashes. However, all mouthwashes significantly reduced the total bleeding scores to <10% in 53% of the patients, compared to the baseline record. Additionally, teeth underwent shade changes in association with all interventions by the end of the study. Analysis of feedback about the mouthwashes showed that the participants seemed to prefer the HA mouthwash over the other mouthwashes.

CONCLUSIONS

CHX remains the most effective antiplaque mouthwash although HA and antioxidants are as effective as CHX in reducing bleeding. In addition, based on its better acceptance by the participants, HA is potentially a good alternative to CHX.

[Prevention of complications in patients with cleft lip and palate combined with teeth crowding receiving long-term orthodontic treatment]

This study aim was to improve the effectiveness of treatment of patients with cleft lip and palate in combination with crowding of teeth receiving long-term orthodontic treatment. The study involved 30 patients divided in 3 groups in which chlorhexidine-containing medication was included in the individual prevention and treatment program. The effectiveness of using 0.2% CG gel was assessed after 6 months to control the development of inflammatory phenomena in periodontal tissues during long-term orthodontic treatment. The obtained clinical and laboratory data indicate the normalization of the cytokine profile and oral hygiene indices as a result of using a CG-containing preparation for effective control of the biofilm etiological factor.

Rational design of peptides with enhanced antimicrobial and anti-biofilm activities against cariogenic bacterium Streptococcus mutans

Streptococcus mutans (S. mutans) is known to be a leading cariogenic pathogen in the oral cavity. Antimicrobial peptides possess excellent properties to combat such pathogens. In this study, we compared the antimicrobial activity of novel linear reutericin 6- and/or gassericin A-inspired peptides and identified LR-10 as the leading peptide. Antibacterial assays demonstrate that LR-10 is more active against S. mutans (3.3 μM) than many peptide-based agents without resistance selection, capable of killing many oral pathogens, and tolerant of physiological conditions. LR-10 also presented a faster killing rate than chlorhexidine and erythromycin, and appeared to display selective activity against S. mutans within 10 s. S. mutans is usually encased in plaque biofilms. Biofilm inhibitory assays indicated that LR-10 had excellent inhibitory effect on the biofilm formation of S. mutans and biofilm-encased cells in vitro at low concentrations (6.5 μM). Consistent with most peptides, LR-10 kills S. mutans mainly by disrupting the cell membranes. Notably, both hemolytic activity assays and cytotoxicity tests indicated that LR-10 could keep biocompatible at the effective concentrations. Hence, LR-10 could be a good candidate for clinical treatment of dental caries.

Potential of Piper betle extracts on inhibition of oral pathogens

In the present study, antimicrobial activity of Piper betle crude ethanol extract against 4 strains of oral pathogens; Candida albicans DMST 8684, C. albicans DMST 5815, Streptococcus gordonii DMST 38731 and Streptococcus mutans DMST 18777 was compared with other medicinal plants. P. betle showed the strongest antimicrobial activity against all tested strains. Fractionated extracts of P. betle using hexane, ethyl acetate, and ethanol, respectively, were subjected to antimicrobial assay. The result revealed that the fractionated extract from ethyl acetate (F-EtOAc) possessed the strongest antimicrobial activity against all tested strains. Its inhibition zones against those pathogens were 23.00 ± 0.00, 24.33 ± 0.58, 12.50 ± 0.70 and 11.00 ± 0.00 mm, respectively and its minimum inhibitory concentrations were 0.50, 1.00, 0.50 and 1.00 mg/mL, respectively. Interestingly, the minimum concentration to completely kill those pathogens was the same for all strains and found to be 2.00 mg/mL. Killing kinetic study revealed that the activity of F-EtOAc was dose dependent. HPLC chromatograms of P. betle extracts were compared with its antimicrobial activity. An obvious peak at a retention time of 4.11 min was found to be a major component of F-EtOAc whereas it was a minor compound in the other extracts. This peak was considered to be an active compound of P. betle as it was consistent with the antimicrobial activity of F-EtOAc, the most potential extract against the tested pathogens. It is suggested that F-EtOAc is a promising extract of P. betle for inhibition of oral pathogens. Separation and structure elucidation of the active compound of this extract will be further investigated.

The Significance of Lactoperoxidase System in Oral Health: Application and Efficacy in Oral Hygiene Products

Lactoperoxidase (LPO) present in saliva are an important element of the nonspecific immune response involved in maintaining oral health. The main role of this enzyme is to oxidize salivary thiocyanate ions (SCN^-) in the presence of hydrogen peroxide (H₂O₂) to products that exhibit antimicrobial activity. LPO derived from bovine milk has found an application in food, cosmetics, and medical industries due to its structural and functional similarity to the human enzyme. Oral hygiene products enriched with the LPO system constitute an alternative to the classic fluoride caries prophylaxis. This review describes the physiological role of human salivary lactoperoxidase and compares the results of clinical trials and in vitro studies of LPO alone and complex dentifrices enriched with bovine LPO. The role of reactivators and inhibitors of LPO is discussed together with the possibility of using nanoparticles to increase the stabilization and activity of this enzyme.

Bactericidal and Virucidal Activity of Povidone-Iodine and Chlorhexidine Gluconate Cleansers in an In Vivo Hand Hygiene Clinical Simulation Study

Introduction

Standard in vitro and in vivo tests help demonstrate efficacy of hand hygiene products; however, there is no standard in vivo test method for viruses. We investigated the bactericidal and virucidal efficacy of povidone-iodine (PVP-I) 7.5% scalp and skin cleanser, chlorhexidine gluconate (CHG) 4% hand cleanser and the reference hand wash (soft soap) in 15 healthy volunteers following European Standard EN1499 (hygienic hand wash test method for bacteria), which was adapted for virucidal testing.

Methods

Separate test series were performed for bactericidal (Escherichia coli) and virucidal [murine norovirus (MNV)] testing. After pre-washing and artificial contamination of hands with test organisms, volunteers underwent testing with 3 and 5 mL of each product for contact times of 15, 30 and 60 s according to a Latin-square randomization. The number of test organisms released from fingertips into sampling fluids was assessed before and after hand washing and mean log₁₀ reduction factor (RF) was calculated. RFs (test-reference) were compared using a Wilcoxon–Wilcox multiple comparisons test per EN1499; efficacy was concluded if p ≤ 0.01.

Results

PVP-I 7.5% and CHG 4% cleansers both passed EN1499 requirements against E. coli, with statistically significantly greater (p ≤ 0.01) mean log₁₀ RFs compared with reference soft soap across all tests (PVP-I: 4.09–5.27; CHG: 4.12–5.22; soap: 2.75–3.11). The experimental design using EN1499 was applicable to testing with MNV as discriminatory and reproducible results were generated. Mean log₁₀ RFs of MNV were statistically significantly greater for PVP-I (1.57–2.57) compared with soft soap (1.24–1.62), while mean log₁₀ RFs with CHG (0.90–1.34) were lower than for soft soap across all tests.

Conclusion

PVP-I 7.5% cleanser showed superior efficacy against MNV compared to soft soap and CHG 4% cleanser, while both PVP-I and CHG were superior to soft soap against E. coli. The experimental set-up may be applicable to future testing for antiviral hand washes.

Funding

Mundipharma Manufacturing Pte Ltd.

Plain Language Summary

Plain language summary available for this article.

The clinical evaluation of Vi-one chlorhexidine mouthwash on plaque-induced gingivitis: A double-blind randomized clinical trial

Background

Chlorhexidine (CHX) is the most effective antiseptic mouthwash to date. Essential oil such as thymol, have inhibitory and biocidal effects a range of bacteria.

Objective

To determine the effect of mouthwash containing CHX and thymol on plaque induced gingivitis.

Methods

This double-blind randomized clinical trial study was performed on 60 patients with plaque induced gingivitis who were randomly divided into two groups: Group I (CHX/thymol mouthwash-Vi-one) and Group II (CHX mouthwash-Behsa). Patients in each group underwent scaling and root planning and polishing, then were educated about BASS-Method brushing, and were recommended Oral-B toothbrushes and Pooneh toothpaste. The two groups were asked to rinse their mouths for 60 seconds twice a day, once in the morning and once at night, after brushing their teeth. Plaque index, gingival index, bleeding index and stain index were evaluated at baseline and 14 days later in Ramfjord teeth. Data analysis was conducted using SPSS version 21. Independent-samples t-test and paired-samples t-test were used for data analysis.

Results

The results showed that plaque index and gingival index significantly reduced in two groups (p<0.001). However, group I was significantly more efficient than group II (p<0.001, p=0.021 respectively). Similar results were observed in terms of bleeding index with the difference that the two groups did not differ significantly from each other (p=0.879). Both groups significantly increased the stain index. No remarkable difference was also observed between the two groups (p=0.754).

Conclusion

Based on the results of this study, we can conclude that the CHX/thymol mouthwash can be offered to patients with dental plaque-induced gingivitis, because it appears to be more effective in controlling dental plaque and gingivitis.

Trial registration

The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT201602231760N45.

Funding

This study was part of a thesis and research project (Grant No: 9440921) supported and funded by Babol University of Medical Sciences. The authors received no financial support from Behsa pharmaceutical company (Behsa mouthwash manufacturer) or Rojin cosmetic laboratory (Vi-one mouthwash manufacturer) for this study.

Antibacterial and Antibiofilm Activities of a Novel Synthetic Cyclic Lipopeptide against Cariogenic Streptococcus mutans UA159

Despite continuous efforts to control cariogenic dental biofilms, very few effective antimicrobial treatments exist. In this study, we characterized the activity of the novel synthetic cyclic lipopeptide 4 (CLP-4), derived from fusaricidin, against the cariogenic pathogen Streptococcus mutans UA159. We determined CLP-4's MIC, minimum bactericidal concentration (MBC), and spontaneous resistance frequency, and we performed time-kill assays. Additionally, we assessed CLP-4's potential to inhibit biofilm formation and eradicate preformed biofilms. Our results demonstrate that CLP-4 has strong antibacterial activity in vitro and is a potent bactericidal agent with low spontaneous resistance frequency. At a low concentration of 5 μg/ml, CLP-4 completely inhibited S. mutans UA159 biofilm formation, and at 50 μg/ml, it reduced the viability of established biofilms by >99.99%. We also assessed CLP-4's cytotoxicity and stability against proteolytic digestion. CLP-4 withstood trypsin or chymotrypsin digestion even after treatment for 24 h, and our toxicity studies showed that CLP-4 effective concentrations had negligible effects on hemolysis and the viability of human oral fibroblasts. In summary, our findings showed that CLP-4 is a potent antibacterial and antibiofilm agent with remarkable stability and low nonspecific cytotoxicity. Hence, CLP-4 is a promising novel antimicrobial peptide with potential for clinical application in the prevention and treatment of dental caries.

Inhibitory activities of selected Sudanese medicinal plants on Porphyromonas gingivalis and matrix metalloproteinase-9 and isolation of bioactive compounds from Combretum hartmannianum (Schweinf) bark

Background

Periodontal diseases are one of the major health problems and among the most important preventable global infectious diseases. Porphyromonas gingivalis is an anaerobic Gram-negative bacterium which has been strongly implicated in the etiology of periodontitis. Additionally, matrix metalloproteinases-9 (MMP-9) is an important factor contributing to periodontal tissue destruction by a variety of mechanisms. The purpose of this study was to evaluate the selected Sudanese medicinal plants against P. gingivalis bacteria and their inhibitory activities on MMP-9.

Methods

Sixty two methanolic and 50% ethanolic extracts from 24 plants species were tested for antibacterial activity against P. gingivalis using microplate dilution assay method to determine the minimum inhibitory concentration (MIC). The inhibitory activity of seven methanol extracts selected from the 62 extracts against MMP-9 was determined by Colorimetric Drug Discovery Kit. In search of bioactive lead compounds, Combretum hartmannianum bark which was found to be within the most active plant extracts was subjected to various chromatographic (medium pressure liquid chromatography, column chromatography on a Sephadex LH-20, preparative high performance liquid chromatography) and spectroscopic methods (liquid chromatography-mass spectrometry, Nuclear Magnetic Resonance (NMR)) to isolate and characterize flavogalonic acid dilactone and terchebulin as bioactive compounds.

Results

About 80% of the crude extracts provided a MIC value ≤4 mg/ml against bacteria. The extracts which revealed the highest potency were: methanolic extracts of Terminalia laxiflora (wood; MIC = 0.25 mg/ml) followed by Acacia totrtilis (bark), Ambrosia maritima (aerial part), Argemone mexicana (seed), C. hartmannianum (bark), Terminalia brownii (wood) and 50% ethanolic extract of T. brownii (bark) with MIC values of 0.5 mg/ml. T. laxiflora (wood) and C. hartmannianum (bark) which belong to combretaceae family showed an inhibitory activity over 50% at the concentration of 10 μg/ml against MMP-9. Additionally, MMP-9 was significantly inhibited by terchebulin with IC₅₀ value of 6.7 μM.

Conclusions

To the best of our knowledge, flavogalonic acid dilactone and terchebulin were isolated from C. hartmannianium bark for the first time in this study. Because of terchebulin and some crude extracts acting on P. gingivalis bacteria and MMP-9 enzyme that would make them promising natural preference for preventing and treating periodontal diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1735-y) contains supplementary material, which is available to authorized users.

Attitudes of Students of Differenet Schools of University of Zagreb on Tooth Bleaching

OBJECTIVE

To compare the awareness that students from four different faculties within the University of Zagreb have of oral health and tooth bleaching procedure.

MATERIALS AND METHODS

The study included 158 subjects (both male and female) - 38 students from the School of Dental Medicine and 40 students from each of the following faculties: the School of Medicine, the Faculty of Economics and the Faculty of Civil Engineering. The respondents were asked to fill out the survey with multiple choices by marking the answers they considered correct.

RESULTS

Only 12% of the respondents followed the information on oral health. More than two thirds of all subjects brush their teeth twice a day, but there were no statistically significant differences between the subjects with respect to college or gender. More than half of the participants (55%) were satisfied, and 12% were completely satisfied with their dental appearance. About 80% of the respondents were aware of differences between teeth bleaching and teeth polishing procedures, with greater prevalence among Dental Medicine and Medicine students. 80% of all subjects would go to a dental office if they decided to whiten their teeth while less than a half (46%) of all the subjects believed that a tooth bleaching has some adverse side-effects.

CONCLUSIONS

There is a difference in knowledge on oral hygiene and tooth bleaching between the students from the School of Dental Medicine, the School of Medicine, the Faculty of Economics and those from the Faculty of Civil Engineering. Dental students have the best knowledge on tooth bleaching and oral health, which was in accordance with their educational guidance and level of education.

Comparative Evaluation of Arimedadi Oil with 0.2% Chlorhexidine Gluconate in Prevention of Plaque and Gingivitis: A Randomized Clinical Trial

INTRODUCTION

Chemical plaque control measures are advocated to maintain proper oral hygiene. Ayurvedic medicines are alternatives considered with minimal side effects to treat systemic diseases and dental diseases. So the present study was conducted to assess the anti-plaque efficacy of Arimedadi (herbal) oil against 0.2% Chlorhexidine gluconate mouthwash.

AIM

To assess the anti-plaque efficacy of Arimedadi (herbal) oil against 0.2% Chlorhexidine gluconate mouthwash.

MATERIALS AND METHODS

A total of 45 patients aged 18 to 21 years, with mild to moderate gingivitis were recruited and were divided randomly into three groups with 15 subjects in each group. After baseline data, scaling and polishing was performed. Group A, as Control, Group B, Chlorhexidine gluconate mouthwash and Group C used experimental Arimedadi oil mouthwash. Instructions were given to use 10 ml mouthwash twice daily after 30 min of tooth brushing for 1 min till 21 days. Plaque Index (PI) and Gingival Index (GI) were taken to assess Plaque and Gingival health on 7(th) day, 14(th) day and at 21(st) day. The statistical analysis was done using Paired t-test and analysis of variance (ANOVA) followed by Post Hoc test.

RESULTS

There was similar improvement in gingival health among both groups compared to control group up to 21 days (p<0.001). However from 14(th) day to 21(st) day there was no difference in gingival health between Chlorhexidine and Arimedadi group (p>0.05).

CONCLUSION

Arimedadi oil is equally effective to Chlorhexidine gluconate as an adjunct to mechanical plaque control in prevention of plaque accumulation and gingivitis. Arimedadi oil could be an effective and safe alternative to 2% Chlorhexidine gluconate mouthwash due to its prophylactic and therapeutic benefits.

A randomised clinical trial to evaluate the effect of a 67 % sodium bicarbonate-containing dentifrice on 0.2 % chlorhexidine digluconate mouthwash tooth staining

Background

Gingivitis can develop as a reaction to dental plaque. It can be limited by curtailing plaque build-up through actions including tooth brushing and the use of medicinal mouthwashes, such as those containing chlorhexidine digluconate (CHX), that can reach parts of the mouth that may be missed when brushing. This study aimed to compare dental stain control of twice-daily brushing with a sodium fluoride (NaF) dentifrice containing 67 % sodium bicarbonate (NaHCO₃) or a commercially available NaF silica dentifrice without NaHCO_3, while using a mouthwash containing 0.2 % CHX.

Methods

This was a 6-week, randomised, two-site, examiner-blind, parallel-group study in healthy subjects with at least ‘mild’ stain levels on the facial surfaces of ≥4 teeth and ≥15 bleeding sites. Assessment was via modified Lobene Stain Index (MLSI), the score being the mean of stain intensity multiplied by area (MLSI [IxA]).

Results

One hundred and fifty of 160 randomised subjects completed the study. There were no significant differences in Overall (facial and lingual) MLSI (IxA) scores between dentifrices. The Facial MLSI (IxA) was statistically significant at 6 weeks, favouring the 67 % NaHCO₃ dentifrice (p = 0.0404). Post-hoc analysis, conducted due to a significant site interaction, found significant differences for all MLSI scores in favour of the 67 % NaHCO₃ dentifrice at Site 1 (both weeks) but not Site 2.

Conclusions

No overall significant differences were found between a 67 and 0 % NaHCO₃ dentifrice in controlling CHX stain; a significant difference on facial surfaces suggests advantage of the former on more accessible surfaces.

Trial registration

This study was registered at ClinicalTrials.gov (NCT01962493) on 10 October 2013 and was funded by GSK Consumer Healthcare.

The staining effect of different mouthwashes containing nanoparticles on dental enamel

Background

This study aimed to evaluate the effects of several mouthwashes containing nanoparticles on discoloration of dental enamel, and compare the results with that of 0.2% chlorhexidine (CHX).

Material and Methods

Sixty intact premolars were randomly assigned to six groups. A spectrophotometer was used to measure the color of the teeth (T1) according to the CIELAB system. The specimens in groups 1 to 4 were then immersed in colloidal solutions containing nanoTiO2 (Group 1), nanoZnO (Group 2), nanoAg (Group 3) and nanoCuO (Group 4). In groups 5 and 6, a 0.2% CHX mouthwash and distilled water were used as positive and negative controls, respectively. After 24 hours of immersion, color determination was repeated (T2). The third color assessment was accomplished after brushing (T3). The L, a, and b values were recorded and the color change (?E) between different stages was calculated.

Results

ANOVA revealed significant between-group differences in the color change between T1 and T2 stages, as well as between T1 and T3 time points (p<0.05), whereas the color change between T2 and T3 was not significantly different among the study groups (p=0.09). ?ET1-T3 was significantly lower in the specimens immersed in distilled water or CHX as compared to the nanoparticle-containing mouthwashes (p<0.05). The highest ?E value pertained to the specimens immersed in nanoZnO-containing solution. The TiO2 nanoparticles caused the lowest staining among the tested nanoparticles.

Conclusions

The mouthwashes containing nanoparticles produced comparable or even greater enamel discoloration compared to CHX. Brushing had little effect on removal of induced stains.

Key words:Nanoparticle, mouthrinse, mouthwash, staining, enamel, discoloration, chlorhexidine.

Antifungal Effect of Zataria multiflora Essence on Experimentally Contaminated Acryl Resin Plates With Candida albicans

Background:

Adherence and colonization of Candida species particularly C. albicans on denture surfaces, forms a microbial biofilm, which may result denture stomatitis in complete denture users.

Objectives:

The purpose of the present study was to evaluate the antifungal effect Zataria multiflora essence in removing of Candida albicans biofilms on experimentally contaminated resin acryl plates.

Materials and Methods:

In the present experimental study, 160 resin acrylic plates (10 × 10 × 1 mm) were contaminated by immersion in 1 × 10³ C. albicans suspension for 24 hours to prepare experimental Candida biofilms. The total number of Candida cells, which adhered to 20 randomly selected acryl resin plates was determined as the Candia load before cleaning. The remaining 140 plates were divided to seven groups of 20 and immersed in five concentrations of Zataria multiflora essence from 50 to 3.125 mg/mL as test, 100000 IU nystatin as the positive and sterile physiologic serum as the negative control. The remaining Candida cells on each acryl plate were also enumerated and data were analyzed using the SPSS 16 software with Kruskal-Wallis and Wilcoxon tests.

Results:

Zataria essence at concentrations of 50 and 25 mg/mL removed 100% of attached Candida cells similar to nystatine (MFC), while weaker Zataria essence solutions cleaned 88%, 60.5% and 44.7% of attached Candida cells. Kruskal-wallis test showed a statistically significant difference between all test groups (P = 0.0001). In this study 12.5 mg/mL concentration of Zataria multiflora was considered as the minimum inhibitory concentration (MIC₉₀).

Conclusions:

Zataria essence, at concentrations of 50 and 25 mg/mL, effectively removed Candida cells that had adhered to the denture surface, similar to the level of removal observed for 100000 IU nystatin.

Antimicrobial effect of zataria multiflora extract in comparison with chlorhexidine mouthwash on experimentally contaminated orthodontic elastomeric ligatures

OBJECTIVES

Long-term use of orthodontic appliances and fixation ligatures creates a favorable environment for the accumulation of oral normal microflora and increases the risk of enamel demineralization and periodontal disease. The aim of this study was to compare the antimicrobial effects of Zataria Multiflora extract and 0.2% chlorhexidine (CHX) mouthwash on experimentally contaminated orthodontic elastomeric ligatures.

MATERIALS AND METHODS

In this lab trial study, Iranian and foreign-made elastomeric ligatures were experimentally contaminated in Streptococcus mutans, Enterococcus faecalis and Candida albicans suspensions. Ligatures were then decontaminated using 0.2% CHX as the control, 0.5 mg/ml Zataria multiflora extract mouthwashes as the test and phosphate buffered saline (PBS) as the negative control for one hour. Antimicrobial properties of both solutions were evaluated by comparing the mean viable bacterial cell count on both rings after decontamination, using SPSS version 15 software.

RESULTS

The mean viable bacterial cell count on Iranian ligatures was greater than that on foreign-made ligatures before disinfection (P=0.001), however this difference for C. albicans was not statistically significant (P=0.061). Chlorhexidine mouthwash completely eliminated all tested microorganisms attached to both elastomeric rings, but Zataria extract was only capable of completely eliminating C. albicans from both ligatures. Statistically significant differences were found in viable bacterial counts on both ligatures before and after disinfection with Zataria extract (P=0.0001).

CONCLUSION

Zataria multiflora extract has antimicrobial properties and can be used for disinfection of elastomeric ligatures. In vivo studies are required to evaluate the efficacy of the incorporation of this herbal extract in mouthwashes for orthodontic patients.

Medication-related tooth discoloration: a review

Tooth discoloration is a common problem for which patients seek dental care. Various medications can directly or indirectly result in tooth discoloration. As clinicians, it is our responsibility to know these therapeutic drugs which can cause tooth discoloration and educate our fellow colleagues to take necessary precautions when prescribing these medications. Therefore, the objective of this paper is to give an overview of the various medications that can be linked to tooth discoloration and to suggest the precautionary measures that can be taken to avoid or minimize it. Clinical Relevance: Dental discoloration potential of medications always needs to be considered before prescribing them.

The risk of unblinding was infrequently and incompletely reported in 300 randomized clinical trial publications

OBJECTIVES

To assess the proportion of clinical trials explicitly reporting the risk of unblinding, to evaluate the completeness of reporting on unblinding risk, and to describe the reported procedures involved in assessing unblinding.

STUDY DESIGN AND SETTING

We sampled at random 300 blinded randomized clinical trials indexed in PubMed in 2010. Two authors read the trial publications and extracted data independently.

RESULTS

Twenty-four trial publications, or 8% (95% confidence interval [CI], 5, 12%), explicitly reported the risk of unblinding, of which 16 publications, or 5% (95% CI, 3, 8%), reported compromised blinding; and 8 publications, or 3% (95% CI, 1, 5%), intact blinding. The reporting on risk of unblinding in the 24 trial publications was generally incomplete. The median proportion of assessments per trial affected by unblinding was 3% (range 1-30%). The most common mechanism for unblinding was perceptible physical properties of the treatments, for example, a difference in the taste and odor of a typhoid vaccine compared with its placebo.

CONCLUSION

Published articles on randomized clinical trials infrequently reported risk of unblinding. This may reflect a tendency for avoiding reporting actual or suspected unblinding or a genuine low risk of unblinding.