The Experts below are selected from a list of 6630 Experts worldwide ranked by ideXlab platform
Michael D Weir - One of the best experts on this subject based on the ideXlab platform.
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Effects of water-aging for 6 months on the durability of a novel antimicrobial and protein-repellent Dental Bonding agent
International journal of oral science, 2018Co-Authors: Ning Zhang, Michael D Weir, Ke Zhang, Mark A. Reynolds, Yuxing BaiAbstract:Biofilms at the tooth-restoration bonded interface can produce acids and cause recurrent caries. Recurrent caries is a primary reason for restoration failures. The objectives of this study were to synthesize a novel bioactive Dental Bonding agent containing dimethylaminohexadecyl methacrylate (DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine (MPC) to inhibit biofilm formation at the tooth-restoration margin and to investigate the effects of water-aging for 6 months on the dentin bond strength and protein-repellent and antibacterial durability. A protein-repellent agent (MPC) and antibacterial agent (DMAHDM) were added to a Scotchbond multi-purpose (SBMP) primer and adhesive. Specimens were stored in water at 37 °C for 1, 30, 90, or 180 days (d). At the end of each time period, the dentin bond strength and protein-repellent and antibacterial properties were evaluated. Protein attachment onto resin specimens was measured by the micro-bicinchoninic acid approach. A Dental plaque microcosm biofilm model was used to test the biofilm response. The SBMP + MPC + DMAHDM group showed no decline in dentin bond strength after water-aging for 6 months, which was significantly higher than that of the control (P 0.1). In conclusion, a Bonding agent with MPC and DMAHDM achieved a durable dentin bond strength and long-term resistance to proteins and oral bacteria. The novel Dental Bonding agent is promising for applications in preventive and restorative dentistry to reduce biofilm formation at the tooth-restoration margin. A strong, long-lasting Bonding agent developed by researchers in the US and China can protect tooth restorations from bacteria and proteins. Tooth restorations often fail due to recurrent decay which starts when bacteria invade the interface between the tooth and the restoration material, producing acids. To combat this problem, Ning Zhang at the University of Maryland, Baltimore, and Capital Medical University, Beijing, and co-workers infused the commercial Scotchbond Multi-Purpose primer and adhesive with two chemicals known to inhibit the formation of bacterial biofilms. The team stored bonded teeth in warm water for six months, after which they found no decline in the bond strength, or its resistance to oral proteins and bacteria. They hope that by incorporating the same protective chemicals into cements, composites and sealants, failure rates in tooth restorations could be reduced.
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Novel multifunctional Dental Bonding agent for class-V restorations to inhibit periodontal biofilms
RSC advances, 2017Co-Authors: Lin Wang, Michael D Weir, Ke Zhang, Yanmin Zhou, Mark A. ReynoldsAbstract:We recently developed a Dental Bonding agent to bond restorations to teeth using nanoparticles of amorphous calcium phosphate (NACP) for remineralization with rechargeable calcium and phosphate ion release. The objectives of this study were to: (1) incorporate an antibacterial monomer dimethylaminohexadecyl methacrylate (DMAHDM) and a protein-repellent agent 2-methacryloyloxyethyl phosphorylcholine (MPC); and (2) investigate protein adsorption and periodontitis-related biofilms for the first time. A primer, used to prime tooth structures for Bonding, was made with pyromellitic glycerol dimethacrylate (PMGDM) and 2-hydroxyethyl methacrylate (HEMA). An adhesive was made with PMGDM, ethoxylated bisphenol A dimethacrylate and HEMA. NACP, MPC and DMAHDM were incorporated. Streptococcus gordonii, Actinomyces naeslundii, Porphyromonas gingivalis, Fusobacterium nucleatum were cultured to form single and multi-species biofilms. Colony-forming units (CFU), live/dead, metabolic activity, and polysaccharide were measured. Adding DMAHDM, MPC and NACP into the Bonding agent did not compromise the dentin bond strength (p > 0.1). Bonding agents with 5% MPC reduced protein adsorption to 1/15 that of the control (p < 0.05). Bonding agents with 5% DMAHDM + 5% MPC had much greater reduction in biofilms than DMAHDM or MPC alone (p < 0.05). Biofilm CFU was reduced by 3 to 4 log via DMAHDM + MPC. Metabolic activities and polysaccharide of biofilms were also substantially reduced (p < 0.05). In conclusion, a novel Bonding agent was developed for Dental restorations with inhibition of biofilms, reducing CFU by 3 to 4 log. Besides remineralization and acid-neutralization via NACP to inhibit caries as shown previously, the multifunctional adhesive is promising for root restorations with subgingival margins to suppress periodontal pathogens and protect the periodontium.
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Primer containing dimethylaminododecyl methacrylate kills bacteria impregnated in human dentin blocks
International journal of oral science, 2016Co-Authors: Chen Chen, Michael D Weir, Lei Cheng, Nancy J. Lin, Sheng Lin-gibson, Xuedong ZhouAbstract:A novel antibacterial agent shows promise for use in Dental Bonding agents and other restorative materials. To preserve tooth structure for successful long-term restorations, dentists are now encouraged to remove as little decayed dentin as possible, but this requires new materials and techniques. Hockin HK Xu at the University of Maryland, USA, Xue-Dong Zhou at Sichuan University in China, and co-workers tested Dental primers (chemicals that are applied before adhesive to increase Bonding strength) made with an antibacterial agent called dimethylaminododecyl methacrylate (DMADDM). After treatment with 10% DMADDM primer, dentin infected with the bacterium Streptococcus mutans, a leading cause of decay, showed a far larger bacterial inhibition zone, and a much lower bacterial count than dentin treated with a control primer. DMADDM also outperformed a primer containing an existing antibacterial agent.
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Three-dimensional biofilm properties on Dental Bonding agent with varying quaternary ammonium charge densities
Journal of dentistry, 2016Co-Authors: Han Zhou, Michael D Weir, Huaibing Liu, Mark A. Reynolds, Ke ZhangAbstract:Abstract Objectives Tooth-restoration interfaces are the weak link with secondary caries causing restoration failure. The objectives of this study were to develop an antimicrobial Bonding agent with dimethylaminododecyl methacrylate (DMAHDM), and investigate the effects of quaternary amine charge density on three-dimensional (3D) biofilms on Dental resin for the first time. Methods DMAHDM was synthesized and incorporated into Scotchbond Multi-Purpose Bonding agent at mass fractions of 0% (control), 2.5%, 5%, 7.5% and 10%. Streptococcus mutans bacteria were inoculated on the polymerized resin and cultured for two days to form biofilms. Confocal laser scanning microscopy was used to measure biofilm thickness, live and dead biofilm volumes, and live bacteria percentage in 3D biofilm vs. distance from resin surface. Results Charge density of the resin had a significant effect on the antibacterial efficacy (p Conclusions Adding new antibacterial monomer DMAHDM into Dental Bonding agent yielded a strong antimicrobial activity, substantially decreasing the 3D biofilm thickness, live biofilm volume, and percentage of live bacteria on cross-sections through the biofilm thickness. Significance Novel DMAHDM-containing Bonding agent with capability of inhibiting 3D biofilms is promising for a wide range of Dental restorative and preventive applications to inhibit biofilms at the tooth-restoration margins and prevent secondary caries.
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effect of quaternary ammonium and silver nanoparticle containing adhesives on dentin bond strength and Dental plaque microcosm biofilms
Dental Materials, 2012Co-Authors: Michael D Weir, Lei Cheng, Ke Zhang, Mary Anne S. Melo, Hockin H K XuAbstract:Abstract Objective Antibacterial Bonding agents are promising to hinder the residual and invading bacteria at the tooth–restoration interfaces. The objectives of this study were to develop an antibacterial Bonding agent by incorporation of quaternary ammonium dimethacrylate (QADM) and nanoparticles of silver (NAg), and to investigate the effect of QADM-NAg adhesive and primer on dentin bond strength and plaque microcosm biofilm response for the first time. Methods Scotchbond Multi-Purpose adhesive and primer were used as control. Experimental adhesive and primer were made by adding QADM and NAg into control adhesive and primer. Human dentin shear bond strengths were measured ( n = 10). A Dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate biofilm metabolic activity, colony-forming unit (CFU) counts, lactic acid production, and live/dead staining assay ( n = 6). Results Adding QADM and NAg into adhesive and primer did not compromise the dentin shear bond strength which ranged from 30 to 35 MPa ( p > 0.1). Scanning electron microscopy (SEM) examinations revealed numerous resin tags, which were similar for the control and the QADM and NAg groups. Adding QADM or NAg markedly reduced the biofilm viability, compared to adhesive control. QADM and NAg together in the adhesive had a much stronger antibacterial effect than using each agent alone ( p Significance Without compromising dentin bond strength and resin tag formation, the QADM and NAg containing adhesive and primer achieved strong antibacterial effects against microcosm biofilms for the first time. QADM-NAg adhesive and primer are promising to combat residual bacteria in tooth cavity and invading bacteria at the margins, thereby to inhibit secondary caries. QADM and NAg incorporation may have a wide applicability to other Dental Bonding systems.
Patrícia Nóbrega Rodrigues Pereira - One of the best experts on this subject based on the ideXlab platform.
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The influence of hemostatic agents on dentin and enamel surfaces and Dental Bonding: A systematic review
Journal of the American Dental Association (1939), 2014Co-Authors: Karina De Oliveira Bernades, Fernanda Cristina Pimentel Garcia, Leandro Augusto Hilgert, Ana Paula Dias Ribeiro, Patrícia Nóbrega Rodrigues PereiraAbstract:ABSTRACT Background. Hemostatic agents have been used clinically in dentistry for many years to control bleeding. The authors reviewed scientific publications in which researchers investigated the effects of hemostatic agents on dentin and enamel surfaces and on Bonding of adhesive systems and resin cements. Types of Studies Reviewed. The authors screened PubMed and Scopus databases for studies in English published from 1980 to 2013. They read the titles and abstracts to identify literature that fulfilled the inclusion criteria. The authors included studies in which researchers evaluated the hemostatic action on the dentin and enamel surfaces or its influence on the bond strength of adhesive systems or resin cements. They used cross-referencing to identify more articles. Results. Twenty in vitro studies met the inclusion criteria. Investigators in 12 of these studies evaluated the bond strength to contaminated dentin. Investigators in 10 of these studies reported a significant decrease in bond strength. Those in two studies evaluated the influence of a hemostatic agent on the Dental enamel and reported decreases in bond strength. Researchers also reported significant increases in microleakage of self-etching adhesives on contaminated dentin. Scanning electron microscopy revealed partial removal of the smear layer or an etching effect of dentin as a result of the application of hemostatic agents on dentin. Practical Implications. Adhesive procedures may be affected adversely when performed on dentin and enamel contaminated by hemostatic agents. Hemostatic agents may induce changes in the dentin surface morphology. The results of this review indicate that the bond strength of self-etching adhesive systems is affected more negatively than is that of etch-and-rinse systems. The authors found that a 60-second application of ethylenediaminetetraacetic acid followed by a water spray restored the bond strength of a self-etching adhesive to dentin; use of phosphoric acid for 15 seconds followed by a water spray also was an effective cleaning method. Direct comparison of selected studies was not possible, however, mainly because of methodological differences hampering definitive conclusions.
Ke Zhang - One of the best experts on this subject based on the ideXlab platform.
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Effects of water-aging for 6 months on the durability of a novel antimicrobial and protein-repellent Dental Bonding agent
International journal of oral science, 2018Co-Authors: Ning Zhang, Michael D Weir, Ke Zhang, Mark A. Reynolds, Yuxing BaiAbstract:Biofilms at the tooth-restoration bonded interface can produce acids and cause recurrent caries. Recurrent caries is a primary reason for restoration failures. The objectives of this study were to synthesize a novel bioactive Dental Bonding agent containing dimethylaminohexadecyl methacrylate (DMAHDM) and 2-methacryloyloxyethyl phosphorylcholine (MPC) to inhibit biofilm formation at the tooth-restoration margin and to investigate the effects of water-aging for 6 months on the dentin bond strength and protein-repellent and antibacterial durability. A protein-repellent agent (MPC) and antibacterial agent (DMAHDM) were added to a Scotchbond multi-purpose (SBMP) primer and adhesive. Specimens were stored in water at 37 °C for 1, 30, 90, or 180 days (d). At the end of each time period, the dentin bond strength and protein-repellent and antibacterial properties were evaluated. Protein attachment onto resin specimens was measured by the micro-bicinchoninic acid approach. A Dental plaque microcosm biofilm model was used to test the biofilm response. The SBMP + MPC + DMAHDM group showed no decline in dentin bond strength after water-aging for 6 months, which was significantly higher than that of the control (P 0.1). In conclusion, a Bonding agent with MPC and DMAHDM achieved a durable dentin bond strength and long-term resistance to proteins and oral bacteria. The novel Dental Bonding agent is promising for applications in preventive and restorative dentistry to reduce biofilm formation at the tooth-restoration margin. A strong, long-lasting Bonding agent developed by researchers in the US and China can protect tooth restorations from bacteria and proteins. Tooth restorations often fail due to recurrent decay which starts when bacteria invade the interface between the tooth and the restoration material, producing acids. To combat this problem, Ning Zhang at the University of Maryland, Baltimore, and Capital Medical University, Beijing, and co-workers infused the commercial Scotchbond Multi-Purpose primer and adhesive with two chemicals known to inhibit the formation of bacterial biofilms. The team stored bonded teeth in warm water for six months, after which they found no decline in the bond strength, or its resistance to oral proteins and bacteria. They hope that by incorporating the same protective chemicals into cements, composites and sealants, failure rates in tooth restorations could be reduced.
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Novel multifunctional Dental Bonding agent for class-V restorations to inhibit periodontal biofilms
RSC advances, 2017Co-Authors: Lin Wang, Michael D Weir, Ke Zhang, Yanmin Zhou, Mark A. ReynoldsAbstract:We recently developed a Dental Bonding agent to bond restorations to teeth using nanoparticles of amorphous calcium phosphate (NACP) for remineralization with rechargeable calcium and phosphate ion release. The objectives of this study were to: (1) incorporate an antibacterial monomer dimethylaminohexadecyl methacrylate (DMAHDM) and a protein-repellent agent 2-methacryloyloxyethyl phosphorylcholine (MPC); and (2) investigate protein adsorption and periodontitis-related biofilms for the first time. A primer, used to prime tooth structures for Bonding, was made with pyromellitic glycerol dimethacrylate (PMGDM) and 2-hydroxyethyl methacrylate (HEMA). An adhesive was made with PMGDM, ethoxylated bisphenol A dimethacrylate and HEMA. NACP, MPC and DMAHDM were incorporated. Streptococcus gordonii, Actinomyces naeslundii, Porphyromonas gingivalis, Fusobacterium nucleatum were cultured to form single and multi-species biofilms. Colony-forming units (CFU), live/dead, metabolic activity, and polysaccharide were measured. Adding DMAHDM, MPC and NACP into the Bonding agent did not compromise the dentin bond strength (p > 0.1). Bonding agents with 5% MPC reduced protein adsorption to 1/15 that of the control (p < 0.05). Bonding agents with 5% DMAHDM + 5% MPC had much greater reduction in biofilms than DMAHDM or MPC alone (p < 0.05). Biofilm CFU was reduced by 3 to 4 log via DMAHDM + MPC. Metabolic activities and polysaccharide of biofilms were also substantially reduced (p < 0.05). In conclusion, a novel Bonding agent was developed for Dental restorations with inhibition of biofilms, reducing CFU by 3 to 4 log. Besides remineralization and acid-neutralization via NACP to inhibit caries as shown previously, the multifunctional adhesive is promising for root restorations with subgingival margins to suppress periodontal pathogens and protect the periodontium.
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Three-dimensional biofilm properties on Dental Bonding agent with varying quaternary ammonium charge densities
Journal of dentistry, 2016Co-Authors: Han Zhou, Michael D Weir, Huaibing Liu, Mark A. Reynolds, Ke ZhangAbstract:Abstract Objectives Tooth-restoration interfaces are the weak link with secondary caries causing restoration failure. The objectives of this study were to develop an antimicrobial Bonding agent with dimethylaminododecyl methacrylate (DMAHDM), and investigate the effects of quaternary amine charge density on three-dimensional (3D) biofilms on Dental resin for the first time. Methods DMAHDM was synthesized and incorporated into Scotchbond Multi-Purpose Bonding agent at mass fractions of 0% (control), 2.5%, 5%, 7.5% and 10%. Streptococcus mutans bacteria were inoculated on the polymerized resin and cultured for two days to form biofilms. Confocal laser scanning microscopy was used to measure biofilm thickness, live and dead biofilm volumes, and live bacteria percentage in 3D biofilm vs. distance from resin surface. Results Charge density of the resin had a significant effect on the antibacterial efficacy (p Conclusions Adding new antibacterial monomer DMAHDM into Dental Bonding agent yielded a strong antimicrobial activity, substantially decreasing the 3D biofilm thickness, live biofilm volume, and percentage of live bacteria on cross-sections through the biofilm thickness. Significance Novel DMAHDM-containing Bonding agent with capability of inhibiting 3D biofilms is promising for a wide range of Dental restorative and preventive applications to inhibit biofilms at the tooth-restoration margins and prevent secondary caries.
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effect of quaternary ammonium and silver nanoparticle containing adhesives on dentin bond strength and Dental plaque microcosm biofilms
Dental Materials, 2012Co-Authors: Michael D Weir, Lei Cheng, Ke Zhang, Mary Anne S. Melo, Hockin H K XuAbstract:Abstract Objective Antibacterial Bonding agents are promising to hinder the residual and invading bacteria at the tooth–restoration interfaces. The objectives of this study were to develop an antibacterial Bonding agent by incorporation of quaternary ammonium dimethacrylate (QADM) and nanoparticles of silver (NAg), and to investigate the effect of QADM-NAg adhesive and primer on dentin bond strength and plaque microcosm biofilm response for the first time. Methods Scotchbond Multi-Purpose adhesive and primer were used as control. Experimental adhesive and primer were made by adding QADM and NAg into control adhesive and primer. Human dentin shear bond strengths were measured ( n = 10). A Dental plaque microcosm biofilm model with human saliva as inoculum was used to investigate biofilm metabolic activity, colony-forming unit (CFU) counts, lactic acid production, and live/dead staining assay ( n = 6). Results Adding QADM and NAg into adhesive and primer did not compromise the dentin shear bond strength which ranged from 30 to 35 MPa ( p > 0.1). Scanning electron microscopy (SEM) examinations revealed numerous resin tags, which were similar for the control and the QADM and NAg groups. Adding QADM or NAg markedly reduced the biofilm viability, compared to adhesive control. QADM and NAg together in the adhesive had a much stronger antibacterial effect than using each agent alone ( p Significance Without compromising dentin bond strength and resin tag formation, the QADM and NAg containing adhesive and primer achieved strong antibacterial effects against microcosm biofilms for the first time. QADM-NAg adhesive and primer are promising to combat residual bacteria in tooth cavity and invading bacteria at the margins, thereby to inhibit secondary caries. QADM and NAg incorporation may have a wide applicability to other Dental Bonding systems.
Karina De Oliveira Bernades - One of the best experts on this subject based on the ideXlab platform.
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The influence of hemostatic agents on dentin and enamel surfaces and Dental Bonding: A systematic review
Journal of the American Dental Association (1939), 2014Co-Authors: Karina De Oliveira Bernades, Fernanda Cristina Pimentel Garcia, Leandro Augusto Hilgert, Ana Paula Dias Ribeiro, Patrícia Nóbrega Rodrigues PereiraAbstract:ABSTRACT Background. Hemostatic agents have been used clinically in dentistry for many years to control bleeding. The authors reviewed scientific publications in which researchers investigated the effects of hemostatic agents on dentin and enamel surfaces and on Bonding of adhesive systems and resin cements. Types of Studies Reviewed. The authors screened PubMed and Scopus databases for studies in English published from 1980 to 2013. They read the titles and abstracts to identify literature that fulfilled the inclusion criteria. The authors included studies in which researchers evaluated the hemostatic action on the dentin and enamel surfaces or its influence on the bond strength of adhesive systems or resin cements. They used cross-referencing to identify more articles. Results. Twenty in vitro studies met the inclusion criteria. Investigators in 12 of these studies evaluated the bond strength to contaminated dentin. Investigators in 10 of these studies reported a significant decrease in bond strength. Those in two studies evaluated the influence of a hemostatic agent on the Dental enamel and reported decreases in bond strength. Researchers also reported significant increases in microleakage of self-etching adhesives on contaminated dentin. Scanning electron microscopy revealed partial removal of the smear layer or an etching effect of dentin as a result of the application of hemostatic agents on dentin. Practical Implications. Adhesive procedures may be affected adversely when performed on dentin and enamel contaminated by hemostatic agents. Hemostatic agents may induce changes in the dentin surface morphology. The results of this review indicate that the bond strength of self-etching adhesive systems is affected more negatively than is that of etch-and-rinse systems. The authors found that a 60-second application of ethylenediaminetetraacetic acid followed by a water spray restored the bond strength of a self-etching adhesive to dentin; use of phosphoric acid for 15 seconds followed by a water spray also was an effective cleaning method. Direct comparison of selected studies was not possible, however, mainly because of methodological differences hampering definitive conclusions.
Newell R. Washburn - One of the best experts on this subject based on the ideXlab platform.
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Quantification of macrophage viability and inflammatory response to Dental Bonding resins
Journal of Bioactive and Compatible Polymers, 2006Co-Authors: Leeann O. Bailey, Michael D Weir, Newell R. WashburnAbstract:This study presented a well-characterized biocompatibility profile of Dental Bonding agents in a mouse macrophage in vitro model. The cellular response to four different formulations of Dental Bonding resins and the cell viability was determined. Materials were prepared by photopolymerization and the unreacted monomers were extracted in a buffered medium. Murine macrophages were incubated in the extract medium for 24 h. Cellular viability was assessed by fluorescence microscopy and Wst-1 assay, while flow cytometry was used to quantify the apoptotic response. As an indicator of inflammatory responses, real-time polymerase chain reaction was utilized to quantify elevated cytokine production. These responses were monitored by quantifying the levels of tumor necrosis factor alpha (TNFα) and interleukin-1 β (IL-1β) produced by the cells. Murine macrophage cells exposed to the unfilled resin systems containing glycidyl ether of bisphenol A (Bis-GMA) and 2-hydroxyethyl methacrylate (HEMA) had the most adverse r...