Release characterization and biological effect of Glass Ionomer Functionalized with two different chlorohexidine derivatives: an in vitro study

ABSTRACT Objective: To evaluate the effect of adding two different chlorohexidine derivatives; chlorhexidine hexametaphosphate and chlorhexidine digluconate to glass ionomer at three different concentrations (0.25%, 0.75%and 1.5%) regarding the antibacterial effect, chlorhexidine release and fluoride release. Methods: A total of 405 specimens were prepared and tested after 7 days, 3 months and 6 months of storage in distilled water (n=5).For testing antibacterial effect, chlorhexidine release and fluoride release, the mix was packed in a ready-made Split Teflon molds to obtain disc-shaped specimen with dimensions 10 mm in diameter and 2 mm thickness according to ISO standardizations. One-way ANOVA and One-way repeated measure ANOVA test were used for statistical analysis of data. Results: The incorporation of chlorhexidine into ChemFil Superior glass ionomer cement in both derivatives has high significance ability to provide a long-term antimicrobial effect on Streptococcus mutans and Lactobacillius acidophilus. The chlorhexidine release was increased by adding chlorhexidine in both derivatives to GIC than the unmodified Glass-ionomer cement for study duration. However, the fluoride release was decreased in the modified specimens than the original one. Conclusion: Addition of chlorhexidine enhanced the antibacterial effect of the glass ionomer and chlorhexidine release. However, fluoride release was reduced than original

Influência de substâncias irrigadoras endodônticas na microdureza da dentina radicular: revisão integrativa / Influence of endodontic irrigation substances on the microdurity of the radicular dentin: integrative review

As soluções de irrigação são essenciais como auxiliares na limpeza e desinfecção do sistema de canais radiculares (SCR). Entretanto, essas substâncias químicas podem gerar alterações na composição da dentina. Assim, o presente estudo teve como objetivo avaliar, por meio de uma revisão integrativa, os efeitos do hipoclorito de sódio (NaOCl) a 1%; 2,5%; 3%; 5%; 5,25%; 6% e 17%; digluconato de clorexidina (CHX) a 2% e EDTA 2,5%; 5%; 15% e 17% sobre a microdureza da dentina do canal radicular após sua utilização como solução irrigadora. Foi realizada uma revisão integrativa nas bases de dados: PubMed, Cochrane e Lilacs, utilizando-se os seguintes descritores em inglês: "irrigating solutions"; "chelaling agentes"; "dentin microhardness"; "EDTA"; "sodium hypochlorite"; "chlorhexidine gluconate". Foi utilizado o conector "and" associando dentin microhardness aos outros descritores. Critérios de inclusão: Artigos científicos na área da odontologia, escritos em inglês e português que aborda o tema "As soluções de hipoclorito de sódio (NaOCl), digluconato de clorexidina (CHX) e EDTA influenciam na microdureza da dentina radicular?''. Critérios de exclusão: artigos repetidos em mais de uma base de dados, livros, teses de doutorado, dissertações de mestrado, resumos e trabalhos publicados em congresso. Fortes evidências indicam que o hipoclorito de sódio, digluconato de clorexidina e EDTA influenciam na microdureza da dentina radicular, quando utilizadas como solução irrigadora durante o tratamento endodôntico... (AU)

Irrigation solutions are essential as an aid in cleaning and disinfecting the root canal system (SCR). However, these chemicals can cause changes in the composition of dentin. Thus, the present study aimed to evaluate, through an integrative review, the effects of 1% sodium hypochlorite (NaOCl); 2.5%; 3%; 5%; 5.25%; 6% and 17%; 2% chlorhexidine digluconate (CHX) and 2.5% EDTA; 5%; 15% and 17% on the microhardness of root canal dentin after its use as an irrigating solution. An integrative review was carried out in the databases: PubMed, Cochrane and Lilacs, using the following descriptors in English: "irrigating solutions"; "chelaling agents"; "dentin microhardness"; "EDTA"; "sodium hypochlorite"; "chlorhexidine gluconate". The "and" connector was used, associating dentin microhardness with other descriptors. Inclusion criteria: Scientific articles in the field of dentistry, written in English and Portuguese that address the topic "Do solutions of sodium hypochlorite (NaOCl), chlorhexidine gluconate (CHX) and EDTA influence the microhardness of root dentin?". Exclusion criteria: articles repeated in more than one database, books, doctoral theses, master's dissertations, abstracts and papers published in congress. Strong evidence indicates that sodium hypochlorite, chlorhexidine gluconate and EDTA influence the microhardness of root dentin when used as an irrigating solution during endodontic treatment... (AU)

Reduced susceptibility to chlorhexidine disinfectant among New Delhi metallo‑beta‑lactamase‑1 positive Enterobacteriaceae and other multidrug‑resistant organisms: Report from a tertiary care hospital in Karachi, Pakistan.

We analysed susceptibility of multidrug‑resistant organisms (MDROs) including New Delhi metallo‑beta‑lactamase‑1 positive Enterobacteriaceae to chlorhexidine and compared results to their susceptible counterparts. Susceptibilities of chlorhexidine digluconate in a standard (CHX‑S) preparation and two commercial disinfectants containing different CHX concentrations (2% w/v and 4% w/w) were performed. MDROs had narrower range of higher CHX‑S minimum inhibitory concentrations (MICs) as compared to pan‑sensitive organisms. The MIC values for commercial disinfectants products for MDROs were many folds higher (20–600 times), than CHX‑S for in vitro use. Increasing antibiotic resistance among bacterial isolates can be an indirect marker of reduced susceptibility to chlorhexidine in hospital setting.

Cytotoxicity of modified nonequilibrium plasma with chlorhexidine digluconate on primary cultured human gingival fibroblasts / 华中科技大学学报（医学）（英德文版）

The aim of this study was to investigate the cytotoxicity of modified nonequilibrium plasma with chlorhexidine digluconate (CHX) on human gingival fibroblasts (HGFs), and to evaluate the biosecurity of modified nonequilibrium plasma with 2% CHX as a new method of root canal treatment. Tissue samples taken from human gingiva were primarily cultured and passaged. Cells from passages 3-7 were used. HGFs were treated by modified nonequilibrium plasma with 2% CHX for 0 min (control group), 30 s, 1 min, 1.5 min, 3 min, 5 min, and 10 min, respectively, and then they were incubated for 0, 24, and 48 h. After that, cell counting kit-8 (CCK-8) assay was applied to analyze the cytotoxicity of modified nonequilibrium plasma with 2% CHX on HGFs. There was no significant difference between the 0 h group treated with the modified nonequilibrium plasma for 1 min and the control group (P>0.05). However, there were significant differences between all the other treated groups and the control group (P<0.05). When treated for 1.5 min or shorter, the cell viability was obviously increased; while treated for 3 min or longer, it was obviously reduced. Moreover, when successively cultured for 0, 24, and 48 h, cell viability was decreased at first and then increased in the 3-min-treated and 5-min-treated groups. The modified nonequilibrium plasma with 2% CHX was of no influence on cell viability in 1.5 min treatment, and it could be safely used on root canal treatment.

In vitro Antibacterial Effect of 2% Chlorhexidine Against Enterococcus faecalis in Dentin Previously Irrigated with 5% Sodium Hypochlorite / Efecto Antibacterial in vitro de Clorhexidina 2% contra Enterococcus faecalis en Dentina Irrigada Previamente con Hipoclorito de Sodio 5%

The aim of this study was to observe whether the antibacterial effect of 2% chlorhexidine against Enterococcus faecalis in dentine is altered by previous irrigation with 5% sodium hypochlorite. Dentin discs were prepared with different irrigation protocols: group 1, immersed in 2% CHX for 25 min; group 2 immersed in 5% NaOCl for 25 minutes; group 3, immersed in 5% NaOCl, dried and irrigated with 3 ml of 2% CHX; group 4 and 5 immersed in 5% NaOCl, rinsed with 5 and 25 ml of distilled water respectively, dried and irrigated with 2% CHX. Group 6, immersed in 0.9% sodium chloride. Discs were then placed in agar plates in which E. faecalis was grown and the inhibition zone around each disc was measured after 24 hours of incubation at 37 C. All experimental groups showed E. faecalis growth inhibition. The most effective irrigant was 2% CHX (P<0.05). Groups in which both NaOCl and CHX were used displayed significantly smaller inhibition halos as compared with 2% CHX. Different volumes of water for rinsing did not cause significant improvement in growth inhibition. The antimicrobial effect of 2% chlorhexidine against E. faecalis was significantly reduced when dentin was previously irrigated with 5% sodium hypochlorite despite of rinsing with different volumes of water.

El objetivo de este estudio fue observar si el efecto antibacterial de clorhexidina 2% contra Enterococcus faecalis en dentina puede verse afectado por la irrigación previa con hipoclorito de sodio al 5%.Se cortaron discos de dentina y fueron preparados de acuerdo a diferentes protocolos de irrigación: grupo 1, sumergidos en CHX 2% por 25 min; grupo 2, sumergidos en NaOCl 5% por 25 min; grupo 3 inmersos en NaOCl 5%, secados y posteriormente irrigados con 3 ml de CHX 2%; grupos 4 y 5 inmersos en NaOCl 5% por 25 minutos, lavados con 5 y 25 ml de agua destilada respectivamente, secados e irrigados con 3ml de CHX 2%. Grupo 6 inmersión en solución salina 25 min. Posteriormente, los discos fueron colocados en platos agar en los cuales creció E. faecalis y se midió el diámetro del halo de inhibición en torno a cada disco tras 24 h de incubación aeróbica a 37 C. Todos los grupos experimentales mostraron inhibición de crecimiento de E. faecalis. El irrigante más efectivo fue CHX 2% (P<0.05). Los grupos en los que se utilizó CHX y NaOCl mostraron inhibición significativamente inferior a la observada con CHX sola. El uso de diferentes volúmenes de agua para lavado de la dentina no causó una mejoría significativa en el efecto antimicrobiano observado. El efecto antimicrobiano de la clorhexidina al 2% contra E. faecalis fue reducido significativamente cuando la dentina se irrigó inicialmente con hipoclorito de sodio 5% a pesar del lavado con diferentes volúmenes de agua.

Evaluation of penetration depth of 2% chlorhexidine digluconate into root dentinal tubules using confocal laser scanning microscope

OBJECTIVES: This study evaluated the penetration depth of 2% chlorhexidine digluconate (CHX) into root dentinal tubules and the influence of passive ultrasonic irrigation (PUI) using a confocal laser scanning microscope (CLSM). MATERIALS AND METHODS: Twenty freshly extracted anterior teeth were decoronated and instrumented using Mtwo rotary files up to size 40, 4% taper. The samples were randomly divided into two groups (n = 10), that is, conventional syringe irrigation (CSI) and PUI. CHX was mixed with Rhodamine B dye and was used as the final irrigant. The teeth were sectioned at coronal, middle and apical levels and viewed under CLSM to record the penetration depth of CHX. The data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests. RESULTS: The mean penetration depths of 2% CHX in coronal, middle and apical thirds were 138 microm, 80 microm and 44 microm in CSI group, respectively, whereas the mean penetration depths were 209 microm, 138 microm and 72 microm respectively in PUI group. Statistically significant difference was present between CSI group and PUI group at all three levels (p < 0.01 for coronal third and p < 0.001 for middle and apical thirds. On intragroup analysis, both groups showed statistically significant difference among three levels (p < 0.001). CONCLUSIONS: Penetration depth of 2% CHX into root dentinal tubules is deeper in coronal third when compared to middle and apical third. PUI aided in deeper penetration of 2% CHX into dentinal tubules when compared to conventional syringe irrigation at all three levels.

Evaluation of penetration depth of 2% chlorhexidine digluconate into root dentinal tubules using confocal laser scanning microscope

OBJECTIVES: This study evaluated the penetration depth of 2% chlorhexidine digluconate (CHX) into root dentinal tubules and the influence of passive ultrasonic irrigation (PUI) using a confocal laser scanning microscope (CLSM). MATERIALS AND METHODS: Twenty freshly extracted anterior teeth were decoronated and instrumented using Mtwo rotary files up to size 40, 4% taper. The samples were randomly divided into two groups (n = 10), that is, conventional syringe irrigation (CSI) and PUI. CHX was mixed with Rhodamine B dye and was used as the final irrigant. The teeth were sectioned at coronal, middle and apical levels and viewed under CLSM to record the penetration depth of CHX. The data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests. RESULTS: The mean penetration depths of 2% CHX in coronal, middle and apical thirds were 138 microm, 80 microm and 44 microm in CSI group, respectively, whereas the mean penetration depths were 209 microm, 138 microm and 72 microm respectively in PUI group. Statistically significant difference was present between CSI group and PUI group at all three levels (p < 0.01 for coronal third and p < 0.001 for middle and apical thirds. On intragroup analysis, both groups showed statistically significant difference among three levels (p < 0.001). CONCLUSIONS: Penetration depth of 2% CHX into root dentinal tubules is deeper in coronal third when compared to middle and apical third. PUI aided in deeper penetration of 2% CHX into dentinal tubules when compared to conventional syringe irrigation at all three levels.

Desenvolvimento e controle físico-químico de sabonete líquido com digluconato de clorexidina / Development and physicochemical study of liquid soap containing chlorhexidine digluconate

A pele e as mucosas constituem defesa natural do corpo frente à invasão de microrganismos, que podem estar presentes na superfície cutânea constituindo a biota normal de defesa ou contaminante. Para remoção desses últimos, se faz necessário o uso de substâncias antissépticas, que combinadas com a lavagem simples, conferem descontaminação eficiente da pele. As farmácias de manipulação já estão aptas para desenvolver veículos de bom sensorial, e a eles incorporar os mais diversos ativos. Com a realização desse trabalho objetivou-se desenvolver um de sabonete líquido, com um ativo já comprovadamente eficaz na assepsia das mãos, a clorexidina. Foram elaboradas duas fórmulas levando-se em consideração as incompatibilidades usuais da clorexidina com produtos de características aniônicas. Optou-se, então, por tensoativos com características não iônicas e pelo gel de hidroxietilcelulose. Posteriormente, as formulações foram submetidas a estudos de estabilidade físico-químicos: densidade, viscosidade, pH, características organolépticas (aspecto, cor e odor). Em seguida as amostras foram mantidas em geladeira (-5ºC±2ºC), estufa (45ºC±2ºC) e em temperatura ambiente (25°C±2ºC). As formulações apresentaram alterações somente quando submetidas à temperatura elevada.

The skin and mucous membranes form a natural barrier against the invasion of harmful microorganisms. The elimination of these microorganisms from the skin surface requires the use of antiseptic substances, which combined with simple washing, provide efficient decontamination of the skin. Current compounding pharmacies are capable of developing vehicles with attractive sensorial properties and the incorporation of different active ingredients. The aim of the present study was to develop a liquid soap containing chlorhexidine, which has proven antiseptic effectiveness. Considering the usual incompatibility of chlorhexidine with products displaying anionic characteristics, two formulas were developed – one containing surfactants with non-ionic characteristics and one containing hydroxyethyl cellulose gel. The formulations were submitted to physicochemical studies of density, viscosity, pH and organoleptic characteristics (appearance, color and odor). Samples were then stored under different temperature conditions: refrigerator (-5 ± 2 ºC), greenhouse (45 ± 2 ºC) and room temperature (25 ± 2 ºC). The formulations only exhibited changes when submitted to high temperature.

The sustaining effect of three polymers on the release of chlorhexidine from a controlled release drug device for root canal disinfection / 대한치과보존학회지

The aim of this in vitro study was to evaluate the suitability of using chitosan, poly (lactide-co-glycolide) (PLGA), and polymethyl methacrylate (PMMA) to control the release of chlorhexidine digluconate (CHX) from a prototype of controlled release drug device (CRD) for root canal disinfection. Four different prototypes with different formulations were prepared. Group A (n = 12); The device (absorbent paper point) was loaded with CHX as control. Group B (n = 12); same as group A, but the device was coated with chitosan. In Groups C and D, the device was treated in the same way as group A and then coated three times with 5% PMMA (Group C, n = 12), or coated three times with 3% PLGA (Group D, n = 12). The devices were randomly allocated to experimental groups of 12 each. All CRD prototypes were soaked in 3 mL distilled water. The concentrations of CHX were determined using a UV spectrophotometer. The surface characteristics of each prototype were observed using a scanning electron microscope. The result showed that release rate of CHX was the greatest in the non-coated group, followed by the chitosan-coated group, the PLGA-coated group, and the PMMA-coated group (P < 0.05). Pores were observed on the surface of the prototypes that were coated with PLGA and PMMA. When the pore size was smaller, the release rate was lower. This data indicate that polymer coating can control the release rate of CHX from the CRD prototypes.

Effects of Chlorhexidine digluconate on Rotational Rate of n- (9-Anthroyloxy)stearic acid in Model Membranes of Total Lipids Extracted from Porphyromonas gingivalis Outer Membranes

The purpose of this study was to provide a basis for studying the molecular mechanism of pharmacological action of chlorhexidine digluconate. Large unilamellar vesicles (OPGTL) were prepared with total lipids extracted from cultured Porphyromonas gingivalis outer membranes (OPG). The anthroyloxy probes were located at a graded series of depths inside a membrane, depending on its substitution position (n) in the aliphatic chain. Fluorescence polarization of n- (9-anthroyloxy)stearic acid was used to examine effects of chlorhexidine digluconate on differential rotational mobility, while changing the probes' substitution position (n) in the membrane phospholipids aliphatic chain. Magnitude of the rotational mobility of the intact six membrane components differed depending on the substitution position in the descending order of 16- (9-anthroyloxy)palmitic acid (16-AP), 12, 9, 6, 3 and 2- (9-anthroyloxy)stearic acid (12-AS, 9-AS, 6-AS, 3-AS and 2-AS). Chlorhexidine digluconate increased in a dose-dependent manner the rate of rotational mobility of hydrocarbon interior of the OPGTL prepared with total lipids extracted from cultured OPG, but decreased the mobility of membrane interface of the OPGTL. Disordering or ordering effects of chlorhexidine digluconate on membrane lipids may be responsible for some, but not all of its bacteriostatic and bactericidal actions.