Effect of experimental toothpaste containing hydroxyapatite nanoparticles and propolis, with and without fluoride, on the microcosm biofilm and enamel demineralization.

This study evaluated the antimicrobial and anticaries effects of toothpaste containing hydroxyapatite nanoparticles (nanoHAP - 5 or 10%), xylitol (2 or 3%) and propolis (1 or 2%), associated or not with 1500 ppm fluoride (F). An in vitro model was used with microcosm biofilm produced from a pool of human saliva and McBain saliva (1:50) in the first 8 h of culture on 162 bovine enamel specimens. At the end of the experimental period, analyses of metabolic activity, colony forming units (CFU) and transverse microradiography (TMR) were performed. This study showed a possible decrease in demineralization and increase in remineralization by the commercial toothpaste (1500 ppm F) and for the experimental toothpaste containing the highest concentration of all agents, combined with F. In addition, a reduction in antimicrobial activity possibly caused by propolis and xylitol, mainly in relation to cariogenic bacteria, was observed.

Effect of experimental and commercial artificial saliva formulations on the activity and viability of microcosm biofilm and on enamel demineralization for irradiated patients with head and neck cancer (HNC).

The effect of different artificial saliva formulations on biofilm activity and viability, and on enamel demineralization for head and neck cancer (HNC) patients was evaluated. Irradiated enamel samples were treated (1 min) with BioXtra® or with experimental formulations containing carboxymethylcellulose plus inorganic constituents alone (AS) or containing 0.1 mg mL-1 CaneCPI-5 (AS + Cane), 1.0 mg mL-1 hemoglobin (AS + Hb) or combination of both (AS + Cane + Hb). Phosphate-buffered-saline and chlorhexidine (0.12%) were negative and positive control, respectively. Biofilm was produced from the saliva of five male HNC patients, under 0.2% sucrose exposure for 5 days, and daily treated with the formulations (1 min). No significant effects were observed for the different experimental treatments. BioXtra® significantly reduced lactobacilli, demonstrating antibacterial potential for this group. Chlorhexidine was an effective treatment to significantly reduce all parameters, being an important antimicrobial and anticaries agent. Future in vitro studies must be performed using a new approach for the design of the experimental formulations.

Antibiofilm and anti-caries effects of an experimental mouth rinse containing Matricaria chamomilla L. extract under microcosm biofilm on enamel.

OBJECTIVE: This study evaluated the antibiofilm and anti-caries effects of an experimental mouth rinse containing aqueous extract of Matricaria chamomilla L. METHODS: Microcosm biofilm was produced on bovine enamel, from pooled human saliva mixed with McBain saliva, under 0.2 % sucrose exposure, for 5 days. The biofilm was daily treated using (1 mL/1 min): Vochysia tucanorum Mart. (2.5 mg/mL); Myrcia bella Cambess. (1.25 mg/mL); Matricaria chamomilla L. (20 mg/mL); Malva sylvestris (Malvatricin® Plus-Daudt); 0.12 % Chlorhexidine (PerioGard®-Palmolive, Positive control) and PBS (Negative control). The % dead bacteria, biofilm thickness, EPS biovolume, lactic acid concentration, the CFU counting (total microorganisms, Lactobacillus sp., total streptococci and Streptococcus mutans/S. sobrinus) were determined. Enamel demineralization was measured by TMR. RESULTS: All mouth rinses induced bacterial death compared to PBS (p < 0.0001). The biofilm thickness varied from 12 ±â€¯2 µm (chlorhexidine) to 18 ±â€¯2 µm (V. tucanorum) (ANOVA/Tukey, p < 0.0001). The EPS biovolume varied from 7(4)% (chlorhexidine) to 30(20)% (PBS) (Kruskal-Wallis/Dunn, p < 0.0001). The lactic acid production was reduced by M. sylvestris (1.1 ±â€¯0.2 g/L) and chlorhexidine (0.6 ±â€¯0.2 g/L) compared to PBS (2.6 ±â€¯1.3 g/L) (ANOVA, p < 0.0001). Malva sylvestris and chlorhexidine showed significant low CFU for total microorganisms, Lactobacillus sp. and total streptococci. Only chlorhexidine significantly reduced S. mutans/S. sobrinus. CFUs for total streptococci and Lactobacillus sp, were also significantly reduced by M. chamomilla L. Malva sylvestris (63.4 % of mineral loss reduction), chlorhexidine (47.4 %) and M. chamomilla L. (39.4 %) significantly reduced enamel demineralization compared to PBS (ANOVA/Tukey, p < 0.0001). CONCLUSION: M. chamomilla L. has lower antibiofilm action, but comparable anti-caries effect to those found for chlorhexidine, under this model. CLINICAL RELEVANCE: This study shows that the antibiofilm and anti-caries potential may vary between the commercial and experimental mouth rinses containing natural agents, with promising results for those containing Matricaria chamomilla L. and Malva Sylvestris.

Comparison of human and bovine enamel in a microbial caries model at different biofilm maturations.

OBJECTIVES: To compare human versus bovine enamel when used in microbial caries models; and to evaluate the use of nylon mesh to support biofilm growth over enamel. METHODS: Twenty-four sub-subgroups were included (time factor: 4, 8, and 12 days; substrate factor: human/bovine; mesh factor: yes/no; treatment factor: 18.4 mM NaF (350 ppm F), de-ionized water [DIW]; n = 9/sub-subgroup). Microcosm biofilm from human saliva (IRB approval #1,406,440,799) was grown on enamel specimens for 24-h (Brain Heart Infusion media; 0.2 % sucrose), using active attachment model. Then, pH-cycling took place. At the end of each pH-cycling period, enamel specimens were analyzed: surface microhardness (VHNchange); transverse microradiography (integrated mineral loss [ΔZ], lesion depth [L]). Biofilm was analyzed: lactic acid production (LDH activity); exopolysaccharide (EPS) amount; and viability (12-day sub-groups). Data were analyzed using ANOVA at a 5 % level of significance. RESULTS: The three-way interaction between pH-cycling duration, substrate type, and treatment type was significant for (VHNchange [p < 0.0005], ΔZ [p = 0.0027], and L [p < 0.0001]). VHNchange exhibited increased lesion severity as pH-cycling time increases, in both treatments. VHNchange data indicated a treatment effect in all timepoints. ΔZ and L exhibited higher values with more mature biofilms. ANOVA analyses for LDH and EPS indicated a significance between variables (LDH p = 0.0100; EPS p < 0.0001). Mesh-covered specimens resulted in lower LDH and EPS values in all maturations. ANOVA analyses of viability (12 days) between variables was significant. CONCLUSION: within the study's limitations, human or bovine enamel can be used in microbial in vitro caries models to study biofilm's maturation and anticaries agents. CLINICAL SIGNIFICANCE: This study demonstrated how a known cariostatic effect of a fluoride concentration in toothpastes can be modulated by the maturation stage of oral biofilm. This can represent hard to reach areas in the oral cavity (e.g. in orthodontic patients or patients with intermaxillary fixation following oral and maxillofacial surgeries).

Effect of commercial herbal toothpastes and mouth rinses on the prevention of enamel demineralization using a microcosm biofilm model.

This work evaluated the effects of commercial toothpastes and mouth rinses containing natural/herbal agents on biofilm viability, extracellular polysaccharide (EPS) production and on enamel demineralization in vitro. Microcosm biofilm was produced on bovine enamel for 5 days and treated daily with: Orgânico natural® (toothpaste/mouth rinse), Boni Natural Menta & Malaleuca® (toothpaste/mouth rinse), Propolis & Myrrh® (toothpaste), Colgate Total 12 Clean Mint® (toothpaste, positive control), Malvatricin® Plus (mouth rinse), PerioGard® (mouth rinse, positive control) or PBS (negative control). Tom's Propolis & Myrrh® and Colgate Total 12® toothpastes and Malvatricin® Plus and PerioGard® mouth rinses significantly reduced biofilm viability (p < 0.05). Only PerioGard® had significant effects on biofilm thickness and EPS. Despite the indication that Tom's Propolis & Myrrh® significantly reduced lesion depth, only Colgate Total 12® significantly reduced mineral loss. Malvatricin® Plus significantly reduced mineral loss and lesion depth, as did PerioGard®. Some herbal products, Malvatricin® Plus and Tom's Propolis & Myrrh®, showed anticaries effects.

Protective Effect of 4% Titanium Tetrafluoride Varnish on Dentin Demineralization Using a Microcosm Biofilm Model.

This study evaluated the effect of titanium tetrafluoride (TiF4) varnish on the development of dentin carious lesions. Bovine root dentin samples were treated for 6 h with: (A) 4% TiF4 varnish (2.45% F); (B) 5.42% sodium fluoride (NaF) varnish (2.45% F); (C) 2% chlorhexidine (CHX) gel - positive control; (D) placebo varnish; or (E) untreated - negative control (n = 4 × biological triplicate, n = 12). Treated dentin samples were exposed to human saliva mixed with McBain saliva (1:50) for the first 8 h in 24-well plates. Thereafter, the medium was removed, and McBain saliva containing 0.2% sucrose was applied for 16 h. From days 2 to 5, McBain saliva with sucrose was replaced daily (37°C, 5% CO2). The demineralization was measured using transverse microradiography, while the effect on biofilm was analyzed using viability, extracellular polysaccharide (EPS), and lactic acid production assays. The data were statistically analyzed (p < 0.05). All treatments (fluorides and CHX) significantly reduced the biofilm viability compared to placebo varnish and negative control. However, none of them was able to reduce the colony-forming unit counting for total microorganism, total streptococci, and Streptococcus mutans. NaF significantly reduced the number of Lactobacillus sp. compared to negative control. No effect was seen on lactic acid production neither on EPS synthesis, except that CHX significantly reduced the amount of insoluble EPS. Both fluorides were able to reduce dentin demineralization compared to placebo varnish and negative control; TiF4 had a better effect in reducing mineral loss and lesion depth than NaF. Therefore, TiF4 varnish has the best protective effect on dentin carious lesion formation using this model.

Protein-repellent and antibacterial effects of a novel polymethyl methacrylate resin.

OBJECTIVES: Heat-cured resins are commonly used in orthodontics; however, there is a high incidence of caries, periodontal diseases and denture-induced stomatitis. The objectives of this study were to: (1) develop a new bioactive polymethyl methacrylate (PMMA) resin containing 2-methacryloyloxyethyl phosphorylcholine (MPC) and quaternary ammonium dimethylaminohexadecyl methacrylate (DMAHDM), and (2) investigate the effects on mechanical properties, protein-repellency and antibacterial properties. METHODS: MPC and DMAHDM were mixed into a commercial acrylic resin (Nature Cryl™ MC). Mechanical properties were measured in three-point flexure. Surface roughness was assessed using atomic force microscopy (AFM). Protein adsorption onto the PMMA resin was measured using a micro bicinchoninic acid (BCA) method. A human saliva microcosm model was used to investigate the live/dead staining and metabolic activity of the biofilms. RESULTS: Incorporation of 3% MPC and 1.5% DMAHDM into PMMA resin achieved protein repellent and antibacterial capabilities, without compromising the mechanical properties. PMMA resin with 3% MPC + 1.5% DMAHDM had protein adsorption that was 1/6 that of a commercial control (p < 0.05). The PMMA resin with 3% MPC + 1.5% DMAHDM had much greater reduction in biofilm growth than using MPC or DMAHDM alone (p < 0.05). CONCLUSIONS: A bioactive PMMA resin with a combination of strong protein-repellent and antibacterial capabilities was developed for the first time. The new resin greatly reduced the biofilm growth and metabolic activity, without compromising its mechanical properties. SIGNIFICANCE: Novel PMMA resin is promising for applications in orthodontic retainers and orthodontic appliances to reduce biofilm activity and protein adsorption around the resin.

Novel self-etching and antibacterial orthodontic adhesive containing dimethylaminohexadecyl methacrylate to inhibit enamel demineralization.

Enamel demineralization is one of the most undesired side effects of fixed orthodontic treatment, which will lead to white spot lesions (WSLs) on tooth surfaces. The development of WSLs is due to prolonged accumulation of bacterial plaque and associated acid production. Self-etching adhesives have been used in orthodontic treatments with several advantages over the more traditional acid-etch method. However, current self-etching adhesives in orthodontic treatments have no antibacterial activity. The objectives of this study were to develop a self-etching and antibacterial orthodontic adhesive, and to investigate its enamel bond strength and antibacterial properties. A novel quaternary ammonium monomer dimethylaminohexadecyl methacrylate (DMAHDM) was incorporated into a commercial self-etching adhesive (Adper Easy One, 3M). It showed that the 5% DMAHDM appeared to be optimal in obtaining the strongest antibacterial function without compromising the enamel bond strength both at 15 min and after 30 days of immersion plus thermal cycling.

[Antibacterial dental adhesive containing nanoantibacterial inorganic fillers].

OBJECTIVE: This investigation aimed to develop a novel antibacterial dental adhesive containing nanoantibacterial inorganic fillers and measure the dentin bonding strength, mechanical properties, and antibacterial property of the novel adhesive in vitro. METHODS: Novel nanoantibacterial inorganic fillers containing quaternary ammonium salt with long chain alkyl were synthesized on the basis of previous research. These novel nanoantibacterial inorganic fillers were added into the dental adhesive to prepare novel nanoantibacterial dental resin composite at mass fractions of 0%, 2.5%, 5.0%, 7.5%, and 10%; 0% was used as control. Dentin shear bonding test was used to evaluate the bonding strength. Flexural test was utilized to measure the novel resin composite flexural strength and elastic modulus. A dental plaque microcosm biofilm model with human saliva as inoculum was formed. Colony forming unit, lactic acid production, and live/dead assay of the biofilm on novel dental adhesive were calculated to assess the effect of novel dental adhesive on human dental plaque microcosm biofilm. RESULTS: The dentin shear bond strength, flexural strength, and elastic modulus were 28.9 MPa, 86.6 MPa, and 4.2 GPa, respectively, when the nanoantibacterial inorganic filler mass fraction in the dental adhesive reached approximately 5.0%. Consequently, the dentin shear bond strength and mechanical properties significantly increased. Addition of 2.5% nanoantibacterial inorganic fillers into the dental adhesive exerted no adverse effect on the mechanical properties significantly (P>0.05). Dental adhesive containing 5% or more nanoantibacterial inorganic fillers inhibited the metabolic activity of the dental plaque microcosm biofilm significantly, thereby displaying a strong antibacterial potency (P<0.05). CONCLUSIONS: This novel antibacterial dental adhesive, which contained 5.0% nanoantibacterial inorganic filler, exhibited promising bonding strength, mechanical property, and antibacterial ability. Hence, this adhesive can be potentially used in caries inhibition in dental application.

Effect of a mouthrinse containing Malva sylvestris on the viability and activity of microcosm biofilm and on enamel demineralization compared to known antimicrobials mouthrinses.

The purpose of this study was to evaluate the antimicrobial (anti-biofilm) and anti-caries (enamel demineralization prevention) effects of Malva sylvestris (Malvatricin® Plus) compared with known antimicrobial mouthrinses. Microcosm biofilm was produced on enamel, using inoculum from pooled human saliva mixed with McBain saliva (0.2% sucrose) for 14 days. The biofilm was treated with mouthrinses for 1 min day-1. Oral-B® Complete, Listerine® Zero and Malvatricin® Plus had the greatest effect on the reduction of biofilm viability (p < 0.0001). On the other hand, lactic acid production was reduced significantly with PerioGard®, Noplak® Max and Listerine® Zero compared with the control (p < 0.0001). No significant differences were found among the mouthrinses with respect to the colony-forming unit counting (total microorganisms, total streptococci, mutans streptococci and lactobacilli) and extracellular polysaccharide production. Enamel demineralization was reduced significantly with PerioGard®, Noplak® Max and Malvatricin® Plus compared with the control (p < 0.0001). Malva sylvestris has a comparable anti-caries effect to chlorhexidine mouthrinses.

Effect of Myracrodruon urundeuva and Qualea grandiflora extracts on viability and activity of microcosm biofilm and prevention of enamel demineralization in vitro / Efeito de extratos de Myracrodruon urundeuva All. e Qualea grandiflora Mart. sobre a viabilidade e atividade de biofilme microcosmo e na prevenção da desmineralização do esmalte in vitro

The objective of this study was to evaluate the antimicrobial and anti-caries effects of two plant extracts. The first chapter dealt with a review of the literature whose objective was to discuss the antimicrobial potential of Brazilian natural agents on the biofilm related to dental caries and gingivitis/periodontal disease. The research of the articles was carried out using PubMed. We found a total of 23 papers. Most of the studies were performed using planktonic microorganisms or under clinical trials. Nineteen articles were focused on cariogenic bacteria. From these nineteen articles, eleven were also about periodontopathogenic bacteria. Four studies addressed only periodontopathogenic bacteria. The most tested Brazilian natural agents were green propolis, essential oils of Lippia sidoides and Copaifera sp. Most of the tested agents showed similar results when compared to positive control (essential oils and extracts) or better effect than negative control (green propolis). More studies involving protocols closer to the clinical condition and the use of response variables that allows understanding the mechanism of action of natural agents are necessary before the incorporation of these natural agents into dental products. The second chapter aimed to test the effect of the hydroalcoholic extracts of Myracrodruon urundeuva All. and Qualea grandiflora Mart. leaves on the viability of the microcosm biofilm and on the prevention of enamel demineralization. The microcosm biofilm was produced on bovine enamel, using human saliva pool mixed with McBain saliva (0.2% sucrose) for 14 days. The biofilm was treated daily with the extracts for 1 min. M. urundeuva at 100, 10 and 0.1 µg/ml and Q. grandiflora at 100 and 0.1 µg/ml reduced cell viability similarly to the positive control and significantly more than negative control. M. urundeuva at 1000, 100 and 0.1 µg/ml were able to reduce the counting formation unit-CFU counting of lactobacilli sp. and Streptococcus mutans, while Q. grandiflora at 1000 and 1.0 µg/ml significantly reduced the S. mutans CFU counting. On the other hand, the natural extracts did not reduce the production of extracellular polyssacharides, lactic acid and the development of enamel caries lesions. The third chapter aimed to evaluate the effect of hydroalcoholic extracts of M. urundeuva and Q. grandiflora (alone or combined) on the viability of S. mutans biofilm and the prevention of enamel demineralization. S. mutans strain (ATCC 21175) was reactivated in BHI broth. Minimum inhibitory concentration, minimum bactericidal concentration, minimum biofilm inhibitory concentration and minimum biofilm eradication concentration were determined to choose the concentrations to be tested under the biofilm model. S. mutans biofilm (5x105 CFU/ml) was produced on bovine enamel using McBain saliva with 0.2% sucrose for 3 days. The biofilm was treated daily with the extracts for 1 min. M. urundeuva (isolated or combined) at concentrations equal or higher than 0.625 mg/ml was able to reduce the bacteria viability, whereas Q. grandiflora extract alone showed antimicrobial effect at 5 mg/ml only (p<0.05). On the other hand, none of the extracts was able to reduce the development of enamel caries lesions. Despite the tested natural extracts have antimicrobial effect; they are unable to prevent caries in enamel.(AU)

O objetivo foi avaliar os efeitos antimicrobiano e anti-cárie de dois extratos de plantas. O primeiro capítulo se referiu a uma revisão da literatura cujo objetivo foi discutir o potencial antimicrobiano dos agentes naturais brasileiros sobre o biofilme relacionado à cárie dentária e à gengivite/doença periodontal. A pesquisa dos artigos foi realizada usando o PubMed. Foram encontrados 23 trabalhos. A maioria dos estudos foi realizada utilizando microorganismos na fase planctônica ou ensaios clínicos. Dezenove artigos foram focados em bactérias cariogênicas. Dos dezenove artigos, onze também eram sobre bactérias periodontopatogênicas. Quatro estudos abordaram apenas bactérias periodontopatogênicas. Os agentes naturais brasileiros mais testados foram própolis verde, óleos essenciais de Lippia sidoides e Copaifera sp. Os agentes testados apresentaram resultados similares quando comparados ao controle positivo (óleos essenciais e extratos) ou melhor efeito que o controle negativo (própolis verde). Mais estudos próximos da condição clínica e o uso de variáveis de resposta que permitam entender o mecanismo de ação são necessários, para permitir a incorporação desses agentes naturais em produtos odontológicos. O segundo capítulo teve como objetivo testar o efeito dos extratos hidroalcoólicos de Myracrodruon urundeuva All. e Qualea grandiflora Mart. sobre a viabilidade do biofilme microcosmo e na prevenção da desmineralização do esmalte. O biofilme microcosmo foi produzido em esmalte bovino, utilizando pool de saliva humana misturada à saliva de McBain (0,2% de sacarose) durante 14 dias. O biofilme foi tratado diariamente com os extratos durante 1 min. M. urundeuva a 100, 10 e 0,1 µg/ml e Q. grandiflora a 100 e 0,1 µg/ml reduziram a viabilidade dos microrganismos de forma semelhante ao controle positivo e significativamente maior do que o controle negativo. M. urundeuva a 1000, 100 e 0,1 µg/ml foi capaz de reduzir a contagem de Unidade formadora de colônia-UFC para Lactobacilos totais e Streptococcus mutans, enquanto a Q. grandiflora a 1000 e 1,0 µg/ml reduziu significativamente a contagem de UFC para S. mutans. Os extratos naturais não conseguiram reduzir a produção de polissacarídeos extracelulares-PEC, ácido lático e o desenvolvimento da lesão cariosa em esmalte. O terceiro capítulo teve como objetivo avaliar o efeito dos extratos hidroalcoólicos de M. urundeuva. e Q. grandiflora (sozinhos ou combinados) sobre a viabilidade do biofilme de S. mutans e na prevenção da desmineralização do esmalte. Cepa de S. mutans (ATCC 21175) foi reativada em caldo BHI. Concentração inibitória mínima, concentração bactericida mínima, concentração inibitória mínima de biofilme e concentração de erradicação mínima de biofilme foram determinadas para escolher as concentrações a serem testadas sob o modelo de biofilme. O biofilme de S. mutans (5x105 CFU/ml) foi produzido em esmalte bovino, utilizando saliva de McBain com 0,2% de sacarose durante 3 dias. O biofilme foi tratado diariamente com os extratos durante 1 min. M. urundeuva (isolada ou combinada) nas concentrações iguais ou superiores a 0,625 mg/ml foi capaz de reduzir a viabilidade das bactérias, enquanto que o extrato da Q. grandflora apresentou efeito antimicrobiano somente a 5 mg/ml (p<0,05). Nenhum dos extratos reduziu o desenvolvimento da lesão da cárie. Apesar dos extratos naturais terem efeito antimicrobiano, são incapazes de prevenir o desenvolvimento da lesão cariosa em esmalte.(AU)

Antibacterial dental adhesive containing nanoantibacterial inorganic fillers / 华西口腔医学杂志

OBJECTIVE@#This investigation aimed to develop a novel antibacterial dental adhesive containing nanoantibacterial inorganic fillers and measure the dentin bonding strength, mechanical properties, and antibacterial property of the novel adhesive in vitro.@*METHODS@#Novel nanoantibacterial inorganic fillers containing quaternary ammonium salt with long chain alkyl were synthesized on the basis of previous research. These novel nanoantibacterial inorganic fillers were added into the dental adhesive to prepare novel nanoantibacterial dental resin composite at mass fractions of 0%, 2.5%, 5.0%, 7.5%, and 10%; 0% was used as control. Dentin shear bonding test was used to evaluate the bonding strength. Flexural test was utilized to measure the novel resin composite flexural strength and elastic modulus. A dental plaque microcosm biofilm model with human saliva as inoculum was formed. Colony forming unit, lactic acid production, and live/dead assay of the biofilm on novel dental adhesive were calculated to assess the effect of novel dental adhesive on human dental plaque microcosm biofilm.@*RESULTS@#The dentin shear bond strength, flexural strength, and elastic modulus were 28.9 MPa, 86.6 MPa, and 4.2 GPa, respectively, when the nanoantibacterial inorganic filler mass fraction in the dental adhesive reached approximately 5.0%. Consequently, the dentin shear bond strength and mechanical properties significantly increased. Addition of 2.5% nanoantibacterial inorganic fillers into the dental adhesive exerted no adverse effect on the mechanical properties significantly (P>0.05). Dental adhesive containing 5% or more nanoantibacterial inorganic fillers inhibited the metabolic activity of the dental plaque microcosm biofilm significantly, thereby displaying a strong antibacterial potency (P<0.05).@*CONCLUSIONS@#This novel antibacterial dental adhesive, which contained 5.0% nanoantibacterial inorganic filler, exhibited promising bonding strength, mechanical property, and antibacterial ability. Hence, this adhesive can be potentially used in caries inhibition in dental application.

Novel dental adhesive with triple benefits of calcium phosphate recharge, protein-repellent and antibacterial functions.

OBJECTIVE: A new adhesive containing nanoparticles of amorphous calcium phosphate (NACP) with calcium (Ca) and phosphate (P) ion rechargeability was recently developed; however, it was not antibacterial. The objectives of this study were to: (1) develop a novel adhesive with triple benefits of Ca and P ion recharge, protein-repellent and antibacterial functions via dimethylaminohexadecyl methacrylate (DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine (MPC); and (2) investigate dentin bond strength, protein adsorption, Ca and P ion concentration, microcosm biofilm response and pH properties. METHODS: MPC, DMAHDM and NACP were mixed into a resin consisting of ethoxylated bisphenol A dimethacrylate (EBPADMA), pyromellitic glycerol dimethacrylate (PMGDM), 2-hydroxyethyl methacrylate (HEMA) and bisphenol A glycidyl dimethacrylate (BisGMA). Protein adsorption was measured using a micro bicinchoninic acid method. A human saliva microcosm biofilm model was tested on resins. Colony-forming units (CFU), live/dead assay, metabolic activity, Ca and P ion concentration and biofilm culture medium pH were determined. RESULTS: The adhesive with 5% MPC+5% DMAHDM+30% NACP inhibited biofilm growth, reducing biofilm CFU by 4 log, compared to control (p<0.05). Dentin shear bond strengths were similar (p>0.1). Biofilm medium became a Ca and P ion reservoir having ion concentration increasing with NACP filler level. The adhesive with 5% MPC+5% DMAHDM+30% NACP maintained a safe pH>6, while commercial adhesive had a cariogenic pH of 4. SIGNIFICANCE: The new adhesive with triple benefits of Ca and P ion recharge, protein-repellent and antibacterial functions substantially reduced biofilm growth, reducing biofilm CFU by 4 orders of magnitude, and yielding a much higher pH than commercial adhesive. This novel adhesive is promising to protect tooth structures from biofilm acids. The method of using NACP, MPC and DMAHDM is promising for application to other dental materials to combat caries.

Evaluation of the effect of different commercial mouthrinses on the viability and activity of microcosm biofilm and on enamel demineralization / Avaliação do efeito de diferentes enxaguatórios bucais comerciais sobre a viabilidade e atividade de biofilme microcosmo e a desmineralização do esmalte

The aim of this study was to evaluate the antimicrobial and anticaries effects of different commercial mouthrinses. The first chapter is about a review of literature whose the aim was to discuss the antimicrobial potential of different mouthrinses in respect to the control of dental caries and periodontal disease. The search of papers was conducted using PubMed and the keywords: "antimicrobial agent" or "antiplaque agent," "dental biofilm" and "dental caries" or "periodontal disease" or "gingivitis". We found a total of 22 papers (2011-2015). The main active agents tested were: CHXChlorhexidine, CPC-cetylpyridinium chloride and EO-Essential oils (alcohol/or alcohol-free). CHX was compared to EO in 6 studies, showing superiority in 3 studies, similarity in 1 study and inferiority in 2 studies. CPC has shown lower effect in plaque reduction compared to CHX and EO. More clinical studies are needed for better understanding the mechanism of action and the differences in performance among the antiplaque agents. The second chapter has as aim to compare the antimicrobial and anticaries effects of six commercial mouthrinses (PerioGard®, Noplak® Max, Oral-B® Complete, Listerine® Zero, Malvatricin® Plus and Cepacol® Plus Advanced) under a microcosm biofilm model formed on enamel. A microcosm biofilm was produced on bovine enamel, using inoculum from pooled human saliva mixture with McBain saliva (with 0.2% sucrose), for 14 days. The biofilm was treated with the mouthrinses daily (1 min). The bacterial viability (% death), lactic acid production (mmol/l), the colony-forming unit (CFU) counting for total microorganisms, lactobacilli, total streptococci and mutans streptococci (log10 CFU/mL) and the extracellular polysaccharides production (EPS, mg/g) were quantified in the biofilm. The degree of enamel demineralization was analyzed using transverse microradiography-TMR (%min vol. µm). Oral-B® Complete, Listerine® Zero and Malvatricin® Plus had the greatest effect on the reduction of biofilm viability (69-75% dead cells vs. 13% in the control, p<0.0001). On the other hand, the lactic acid production was significantly reduced by PerioGard®, Noplak® Max and Listerine® Zero compared to control (69% reduction, p<0.0001). There were no significant differences among the mouthrinses in respect to the CFU counting and EPS production. The enamel demineralization was significantly reduced by PerioGard®, Noplak® Max and Malvatricin® Plus compared to control (74% reduction, p<0.0001). Therefore, the commercial mouthrinses have different antimicrobial and anticaries effects. The mouthrinses containing chlorexidine or Malva sylvestris (with F, triclosan and xylitol) had the best anticaries effect under this model.(AU)

O objetivo deste estudo foi avaliar os efeitos antimicrobiano e anticárie de diferentes enxaguatórios bucais comerciais. O primeiro capítulo se refere a uma revisão da literatura cujo objetivo foi discutir o potencial antimicrobiano de diferentes enxaguatórios em relação ao controle de cárie dentária e doença periodontal. A pesquisa dos artigos foi realizada usando o PubMed e as palavras-chave: "agente antimicrobiano" ou "agente antiplaca", "biofilme dental" e "cárie dentária" ou "doença periodontal" ou "gengivite". Encontramos um total de 22 artigos (2011-2015). Os principais agentes ativos testados foram: Clorexidina-CHX, cloreto de cetilpiridínio- CPC e óleos essenciais OE (álcool / ou sem álcool). A CHX foi comparada ao OE em 6 estudos, mostrando superioridade em 3 estudos, similaridade em 1 estudo e inferioridade em 2 estudos. CPC mostrou menor efeito na redução da placa em comparação com CHX e OE. Mais estudos clínicos são necessários para uma melhor compreensão do mecanismo de ação e as diferenças no desempenho entre os agentes antiplaca. O segundo capítulo teve como objetivo avaliar os efeitos antimicrobiano e anticárie de seis enxaguatórios comerciais (PerioGard®, Noplak® Max, Oral-B® Complete, Listerine® Zero, Malvatricin® Plus e Cepacol® Plus Advanced) sobre um modelo de biofilme de microcosmo formado no esmalte. O biofilme de microcosmo foi produzido em esmalte bovino, utilizando o inóculo da mistura de saliva humana com saliva de McBain (com 0,2% de sacarose), durante 14 dias. O biofilme foi tratado com enxaguatórios diariamente (1 min). A viabilidade bacteriana (% de morte), a produção de ácido láctico (mmol/l), as unidades formadoras de colônias (UFC) foram contadas para microrganismos totais, lactobacilos, estreptococos totais e Streptococcus mutans (log10 UFC/mL) e a produção de polissacarídeos extracelulares (PEC, mg/g) foram quantificados no biofilme. O grau de desmineralização do esmalte foi analisado utilizando a microrradiografia transversal-TMR (%min vol. µm). Oral-B® Complete, Listerine® Zero e Malvatricin® Plus tiveram o maior efeito na redução da viabilidade do biofilme (69-75% de morte celular vs 13% no controle, p<0,0001). Por outro lado, a produção de ácido lático foi significativamente reduzida por PerioGard®, Noplak® Max e Listerine® Zero comparado ao controle (redução de 69%, p<0,0001). Não houve diferenças significativas entre os enxaguatórios em relação à contagem de UFC e à produção de PEC. A desmineralização do esmalte foi significativamente reduzida pelo PerioGard®, Noplak® Max e Malvatricin® Plus em comparação ao controle (redução de 74%, p<0,0001). Portanto, os enxaguatórios bucais comerciais têm diferentes efeitos antimicrobiano e anticárie. Os enxaguatórios contendo clorexidina ou Malva sylvestris (com F, triclosan e xilitol) tiveram o melhor efeito anticárie neste modelo.(AU)

Protein-repellent and antibacterial functions of a calcium phosphate rechargeable nanocomposite.

OBJECTIVES: We recently developed a new rechargeable composite with nanoparticles of amorphous calcium phosphate (NACP) having long-term calcium (Ca) and phosphate (P) ion release; however, this composite was not antibacterial. The objectives of this study were to: (1) incorporate dimethylaminohexadecyl methacrylate (DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine (MPC) into rechargeable NACP composite, and (2) investigate mechanical properties, protein adsorption and biofilm response of composite, and the pH of biofilm medium. METHODS: MPC, DMAHDM and NACP were mixed into a resin of ethoxylated bisphenol A dimethacrylate (EBPADMA) and pyromellitic glycerol dimethacrylate (PMGDM). Protein adsorption was measured using a micro bicinchoninic acid method. A human saliva microcosm biofilm model was used to grow biofilms on composites. Colony-forming units (CFU), live/dead assay, metabolic activity, and biofilm culture medium pH were determined. The tests used n=6. RESULTS: The composite with 3% MPC had protein adsorption an order of magnitude less than that of a commercial composite (p<0.05). Control composites were fully covered by live bacteria. Live bacteria were reduced via MPC; 3% MPC+3% DMAHDM had the least live bacteria (p<0.05). The composite with 3% MPC+3% DMAHDM inhibited biofilm growth and viability, reducing biofilm CFU by 3 log compared to commercial control composite (p<0.05), while having a flexural strength similar to that of the commercial composite (p>0.1). The composite containing 3% MPC+3% DMAHDM with biofilm culture maintained a pH above 6.5, while the commercial composite had a cariogenic pH of 4.2 in biofilm culture medium. CONCLUSIONS: The new protein-repellent and antibacterial NACP rechargeable composite substantially reduced biofilm growth, yielding a much higher pH than a commercial composite. CLINICAL SIGNIFICANCE: This novel bioactive nanocomposite is promising to protect tooth structures from biofilm acids and caries. The method of using NACP, MPC and DMAHDM may be applicable to other dental materials to reduce plaque buildup and secondary caries.

Novel Dental Cement to Combat Biofilms and Reduce Acids for Orthodontic Applications to Avoid Enamel Demineralization.

Orthodontic treatments often lead to biofilm buildup and white spot lesions due to enamel demineralization. The objectives of this study were to develop a novel bioactive orthodontic cement to prevent white spot lesions, and to determine the effects of cement compositions on biofilm growth and acid production. 2-methacryloyloxyethyl phosphorylcholine (MPC), nanoparticles of silver (NAg), and dimethylaminohexadecyl methacrylate (DMAHDM) were incorporated into a resin-modified glass ionomer cement (RMGI). Enamel shear bond strength (SBS) was determined. Protein adsorption was determined using a micro bicinchoninic acid method. A dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate metabolic activity, colony-forming units (CFU) and lactic acid production. Incorporating 3% of MPC, 1.5% of DMAHDM, and 0.1% of NAg into RMGI, and immersing in distilled water at 37 °C for 30 days, did not decrease the SBS, compared to control (p > 0.1). RMGI with 3% MPC + 1.5% DMAHDM + 0.1% NAg had protein amount that was 1/10 that of control. RMGI with triple agents (MPC + DMAHDM + NAg) had much stronger antibacterial property than using a single agent or double agents (p < 0.05). Biofilm CFU on RMGI with triple agents was reduced by more than 3 orders of magnitude, compared to commercial control. Biofilm metabolic activity and acid production were also greatly reduced. In conclusion, adding MPC + DMAHDM + NAg in RMGI substantially inhibited biofilm viability and acid production, without compromising the orthodontic bracket bond strength to enamel. The novel bioactive cement is promising for orthodontic applications to hinder biofilms and plaque buildup and enamel demineralization.

Do Dental Resin Composites Accumulate More Oral Biofilms and Plaque than Amalgam and Glass Ionomer Materials?

A long-time drawback of dental composites is that they accumulate more biofilms and plaques than amalgam and glass ionomer restorative materials. It would be highly desirable to develop a new composite with reduced biofilm growth, while avoiding the non-esthetics of amalgam and low strength of glass ionomer. The objectives of this study were to: (1) develop a protein-repellent composite with reduced biofilms matching amalgam and glass ionomer for the first time; and (2) investigate their protein adsorption, biofilms, and mechanical properties. Five materials were tested: A new composite containing 3% of protein-repellent 2-methacryloyloxyethyl phosphorylcholine (MPC); the composite with 0% MPC as control; commercial composite control; dental amalgam; resin-modified glass ionomer (RMGI). A dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate metabolic activity, colony-forming units (CFU), and lactic acid production. Composite with 3% MPC had flexural strength similar to those with 0% MPC and commercial composite control (p > 0.1), and much greater than RMGI (p < 0.05). Composite with 3% MPC had protein adsorption that was only 1/10 that of control composites (p < 0.05). Composite with 3% MPC had biofilm CFU and lactic acid much lower than control composites (p < 0.05). Biofilm growth, metabolic activity and lactic acid on the new composite with 3% MPC were reduced to the low level of amalgam and RMGI (p > 0.1). In conclusion, a new protein-repellent dental resin composite reduced oral biofilm growth and acid production to the low levels of non-esthetic amalgam and RMGI for the first time. The long-held conclusion that dental composites accumulate more biofilms than amalgam and glass ionomer is no longer true. The novel composite is promising to finally overcome the major biofilm-accumulation drawback of dental composites in order to reduce biofilm acids and secondary caries.

Novel protein-repellent and biofilm-repellent orthodontic cement containing 2-methacryloyloxyethyl phosphorylcholine.

The objectives of this study were to develop the first protein-repellent resin-modified glass ionomer cement (RMGI) by incorporating 2-methacryloyloxyethyl phosphorylcholine (MPC) for orthodontic applications, and to investigate the MPC effects on protein adsorption, biofilm growth, and enamel bond strength. MPC was incorporated into RMGI at 0% (control), 1.5%, 3%, and 5% by mass. Specimens were stored in water at 37°C for 1 and 30 days. Enamel shear bond strength (SBS) was measured, and the adhesive remnant index (ARI) scores were assessed. Protein adsorption onto the specimens was determined by a micro bicinchoninic acid method. A dental plaque microcosm biofilm model with human saliva as inoculum was used. The results showed that adding 3% of MPC into RMGI did not significantly reduce the SBS (p > 0.1). There was no significant loss in SBS for RMGI containing 3% MPC after water-aging for 30 days, as compared to 1 day (p > 0.1). RMGI with 3% MPC had protein adsorption that was 1/10 that of control. RMGI with 3% MPC greatly reduced the bacterial adhesion, and lactic acid production and colony-forming units of biofilms, while substantially increasing the medium solution pH containing biofilms. The protein-repellent and biofilm-repellent effects were not decreased after water-aging for 30 days. In conclusion, the MPC-containing RMGI is promising to reduce biofilms and white spot lesions without compromising orthodontic bracket-enamel bond strength. The novel protein-repellent method may have applicability to other orthodontic cements, dental composites, adhesives, sealants, and cements to repel proteins and biofilms. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 949-959, 2016.

Antibacterial and protein-repellent orthodontic cement to combat biofilms and white spot lesions.

OBJECTIVES: White spot lesions are the most undesired side-effect of fixed orthodontic treatments. The objectives of this study were to combine nanoparticles of silver (NAg) with 2-methacryloyloxyethyl phosphorylcholine (MPC) to develop a modified resin-modified glass ionomer cement (RMGI) as orthodontic cement with double benefits of antibacterial and protein-repellent capabilities for the first time. METHODS: NAg and MPC were incorporated into a commercial RMGI. Another commercial orthodontic adhesive also served as control. Enamel shear bond strengths (SBS) were determined. Protein adsorption was measured via a micro bicinchoninic acid method. A dental plaque microcosm biofilm model with human saliva as inoculum was tested. Biofilms adherent on the cement samples and planktonic bacteria in the culture medium away from the cement surfaces were both evaluated for bacterial metabolic activity, colony-forming units (CFU), and lactic acid production. RESULTS: Adding 0.1% NAg and 3% MPC to RMGI, and water-aging for 30 days, did not adversely affect the SBS, compared to the unmodified RMGI control (p>0.1). The modified RMGI containing 0.1% NAg and 3% MPC achieved the greatest reduction in protein adsorption, bacterial adhesion, CFU, metabolic activity and lactic acid production. The RMGI containing 0.1% NAg and 3% MPC inhibited not only the bacteria on its surface, but also the bacteria away from the surface in the culture medium. CONCLUSIONS: The incorporation of double agents (antibacterial NAg+protein-repellent MPC) into RMGI achieved much stronger inhibition of biofilms than using each agent alone. The novel antibacterial and protein-repellent RMGI with substantially-reduced biofilm acids is promising as an orthodontic cement to combat white spot lesions in enamel.

Effect of dimethylaminohexadecyl methacrylate mass fraction on fracture toughness and antibacterial properties of CaP nanocomposite.

OBJECTIVES: Biofilm acids contribute to secondary caries which is a reason for restoration failure. Previous studies synthesized nanoparticles of amorphous calcium phosphate (NACP) and dimethylaminohexadecyl methacrylate (DMAHDM). The objectives of this study were to develop DMAHMD-NACP nanocomposite for double benefits of antibacterial and remineralization capabilities, and investigate the DMAHMD mass fraction effects on fracture toughness and biofilm response of NACP nanocomposite for the first time. METHODS: DMAHDM was incorporated into NACP nanocomposite at mass fractions of 0% (control), 0.75%, 1.5%, 2.25% and 3%. A single edge V-notched beam method was used to measure fracture toughness K(IC). A dental plaque microcosm biofilm model using human saliva as inoculum was used to measure the antibacterial properties of composites. RESULTS: K(IC) was about 1 MPa×m(1/2) for all composite (mean±sd; n=6). Adding DMAHDM from 0% to 3% did not affect K(IC) (p>0.1). Lactic acid production by biofilms on composite containing 3% DMAHDM was reduced to less than 1% of that on composite control. Metabolic activity of adherent biofilms on composite containing 3% DMAHDM was reduced to 4% of that on composite control. Biofilm colony-forming unit (CFU) counts were reduced by three orders of magnitude on NACP nanocomposite containing 3% DMAHDM. CONCLUSIONS: DMAHDM-NACP nanocomposite had good fracture resistance, strong antibacterial potency, and NACP for remineralization (shown in previous studies). The DMAHDM-NACP nanocomposite may be promising for caries-inhibiting dental restorations, and the method of using double agents (DMAHDM and NACP) may have a wide applicability to other dental materials including bonding agents and cements.