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Fu D, Holles SB, England E, Zhang Y, Cheng S, Szczepanski C. Compatibility versus reaction diffusion: Factors that determine the heterogeneity of polymerized adhesive networks. Dent Mater 2024; 40:800-810. [PMID: 38485599 PMCID: PMC11098697 DOI: 10.1016/j.dental.2024.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 02/20/2024] [Accepted: 03/02/2024] [Indexed: 05/18/2024]
Abstract
OBJECTIVES Heterogeneity and phase separation during network polymerization is a major issue contributing to the failure of dental adhesives. This study investigates how the ratio of hydrophobic crosslinkers to hydrophilic comonomer (C/H ratio), as well as cosolvent fraction (ethanol/water) influences the degree of heterogeneity and proclivity for phase separation in a series of model adhesive formulations. METHODS Twelve formulations were investigated, with 4 different C/H ratios (7:1, 2.2:1, 1:1, 0.5:1) and 3 different overall cosolvent fractions (0, 10 and 20 wt%). The heterogeneity and phase behavior were characterized using Fourier Transform Infrared Spectroscopy (FT-IR), dynamic mechanical analysis (DMA), small-angle x-ray scattering (SAXS) and atomic force microscopy (AFM). RESULTS In resins without cosolvent, all characterizations confirm reduced heterogeneity as C/H ratio decreases. However, when 10 or 20 wt% of cosolvent is included in the adhesive formulation, a higher degree of heterogeneity and even distinct phase separation with domains ranging from a few hundreds of nanometers to a few micrometers in size form. This is particularly noticeable at lower C/H ratios, which is surprising as HEMA is commonly considered a compatibilizer between hydrophobic crosslinkers and aqueous (co)solvents. SIGNIFICANCE Our experiments demonstrate that formulations with lower C/H ratio and thus a lower viscosity experience later onsets of diffusion limitations during polymerization, which favors thermodynamically driven phase separation. Therefore, to determine or predict the resulting phase structure of adhesive materials, it is necessary to consider the kinetics and diffusion constraints during the formation of the polymer network and not just the compatibility of resin constituents.
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Affiliation(s)
- Denghao Fu
- Department of Chemical Engineering & Materials Science, Michigan State University, East Lansing MI 48824, USA
| | - Sarah Beth Holles
- Department of Chemical Engineering & Materials Science, Michigan State University, East Lansing MI 48824, USA
| | - Emily England
- Department of Chemical Engineering & Materials Science, Michigan State University, East Lansing MI 48824, USA
| | - Yunlu Zhang
- Department of Chemical Engineering & Materials Science, Michigan State University, East Lansing MI 48824, USA
| | - Shiwang Cheng
- Department of Chemical Engineering & Materials Science, Michigan State University, East Lansing MI 48824, USA
| | - Caroline Szczepanski
- Department of Chemical Engineering & Materials Science, Michigan State University, East Lansing MI 48824, USA.
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How Water Content Can Influence the Chemomechanical Properties and Physical Degradation under Aging of Experimental Adhesives. Int J Dent 2022; 2022:5771341. [PMID: 35265134 PMCID: PMC8898883 DOI: 10.1155/2022/5771341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/18/2022] [Accepted: 02/02/2022] [Indexed: 12/04/2022] Open
Abstract
Objective To evaluate the physicochemical (sorption (SOR), solubility (SOL), and degree of conversion (DC)) and mechanical (flexural strength (FS), modulus of elasticity (ME), and compressive strength (CS)) properties of adhesives with different water contents (D2O). Materials and Methods An adhesive was formulated: 55 wt% BisGMA, 45 wt% HEMA, 0.5 wt% camphorquinone, 0.5 wt% EDMAB, and 1.0 wt% DPIHP. D2O was added into the adhesives (0 wt%, 10 wt%, and 16 wt%). DC was monitored through the FTIR. FS, ME, CS, SOR, and SOL were tested. The adhesive samples were aged in deionized water, ethanol, and acetone. Data were submitted to ANOVA and Tukey's tests (5%). Results For DC, the 0 wt% group showed a significant reduction (68.09 ± 0.14A) compared with the 10 wt% (87.07 ± 0.81B) and 16 wt% groups (89.87 ± 0.24B); 10 wt% showed the highest FS (MPa) mean values (141.6 ± 6.71B) compared with the 0 wt% (109.4 ± 20.5A) and 16 wt% (107.8 ± 15.8A). For the CS (MPa) and ME (GPa), the 16 wt% showed the lowest mean values (98.8 ± 18.0B and 2.2 ± 0.3B, respectively) compared with the 10 wt% and 0 wt%. For the SOR, 16 wt% of water showed the highest mean values and the ethanol showed the lowest mean values of SOL regardless of water content. Conclusion The amount of water content and the types of aging solvents significantly affect the adhesive properties.
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骆 池, 彭 楚, 杨 媛, 秦 满, 王 媛. [Effects of three self-etch adhesives and mild salivary contamination on the bonding durability of deciduous teeth]. BEIJING DA XUE XUE BAO. YI XUE BAN = JOURNAL OF PEKING UNIVERSITY. HEALTH SCIENCES 2020; 53:46-53. [PMID: 33550335 PMCID: PMC7867989 DOI: 10.19723/j.issn.1671-167x.2021.01.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Indexed: 06/12/2023]
Abstract
OBJECTIVE To compare the bonding durability of three different self-etch adhesives to primary enamel and dentin, and to investigate the effect of mild salivary contamination followed by air drying on the bonding durability. METHODS Two hundred and forty enamel specimens were divided randomly into 16 groups (n=15/group)according to the adhesive system [self-etch adhesives: Clearfil SE Bond(SE), AdperTM Easy One (EO), Scotchbond Universal (SBU); total-etch adhesive: AdperTM Single Bond Plus(SL)], contamination status (non-contaminated vs. salivary-contaminated) and storage condition (stored in distilled water for 24 h vs. aging mode 5 000 thermal cycles in 5 ℃ and 55 ℃). Two hundred and forty dentin specimens were assigned in the same way. Shear bond strength for 12 specimens in each group were measured. The adhesive interface for the residual specimens in each group was observed by scanning electron microscopy(SEM). Data were analyzed by three-way analysis of variance and Tukey test(P < 0.05). RESULTS For primary enamel, total-etch adhesive showed higher initial shear bond strength values (28.92±1.83) MPa and shear bond strength values (27.27±3.03) MPa after thermal cycles compared with the other groups, and the difference between the groups was statistically significant (P < 0.01). Shear bond strength values of EO decreased significantly in salivary-treated groups, regardless of storage conditions, and the difference was statistically significant (P < 0.01). For primary dentin, shear bond strength values of EO decreased significantly in salivary-treated groups after 24 h (P < 0.01). After 5 000 thermal cycles, total-etch adhesive showed significantly lower shear bond strength values (14.31±1.97) MPa compared with the other groups, and the difference between the groups was statistically significant (P < 0.01), and shear bond strength values of EO were significantly lower than those in SE and SBU groups (P < 0.01), regardless of contamination status. CONCLUSION Total-etch adhesive SL has better bonding durability to primary enamel. SE and SBU have better bonding durability to primary dentin and have a certain resistance to salivary contamination, while the bonding performance of EO is compromised greatly by mild salivary contamination followed by air drying.
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Affiliation(s)
- 池怡 骆
- />北京大学口腔医学院·口腔医院,儿童口腔科 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
| | - 楚芳 彭
- />北京大学口腔医学院·口腔医院,儿童口腔科 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
| | - 媛 杨
- />北京大学口腔医学院·口腔医院,儿童口腔科 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
| | - 满 秦
- />北京大学口腔医学院·口腔医院,儿童口腔科 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
| | - 媛媛 王
- />北京大学口腔医学院·口腔医院,儿童口腔科 国家口腔疾病临床医学研究中心 口腔数字化医疗技术和材料国家工程实验室 口腔数字医学北京市重点实验室,北京 100081Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Disease & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
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Abedin F, Ye Q, Spencer P. Hydrophilic dyes as photosensitizers for photopolymerization of dental adhesives. J Dent 2020; 99:103405. [PMID: 32522687 DOI: 10.1016/j.jdent.2020.103405] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 05/30/2020] [Accepted: 06/03/2020] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES This study explored hydrophilic dyes as photosensitizers for application in dental adhesives. The goal was to identify dyes that enhance the degree of conversion (DC) of the hydrophilic-rich phase without impairing polymerization of the hydrophobic-rich phase. METHODS Properties that were investigated included the molar extinction coefficient at 480 nm, relative normalized photon absorption efficiency (PAE), rate of polymerization and degree of conversion (DC). The following hydrophilic dyes: Bromophenol blue sodium salt, Rosebengal sodium salt, Erythrosin B, New Fuchsin and Victoria blue B were identified as suitable photosensitizers. RESULTS In this study it was observed that dyes such as Bromophenol blue sodium salt, New Fuchsin, Victoria blue B and Rosebengal sodium salt were suitable candidates for dental adhesive photopolymerization, leading to substantial degree of conversion to both the hydrophilic-rich phase and the hydrophobic-rich phase. CONCLUSIONS In addition to the ability of the photosensitizer to absorb light in the visible range and transition to an excited state as a result of the absorbed energy, other factors such as the efficiency of the photosensitizer/light curing unit (LCU) combination, stability/efficiency of the excited state of the photosensitizer and/or initiating reactive species play an important role in the photopolymerization of the dental adhesive.
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Affiliation(s)
- Farhana Abedin
- Department of Electromechanical Engineering Technology, California State Polytechnic University, 3801 W Temple Ave, Pomona, CA, 91768, United States.
| | - Qiang Ye
- Institute of Bioengineering Research Laboratories, The University of Kansas, 1530 W 15thStreet, Lawrence, KS, 66045, United States.
| | - Paulette Spencer
- Institute of Bioengineering Research Laboratories, The University of Kansas, 1530 W 15thStreet, Lawrence, KS, 66045, United States; Department of Mechanical Engineering, The University of Kansas, 1530 W 15thStreet, Lawrence, KS, 66045, United States.
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Dressano D, Salvador MV, Oliveira MT, Marchi GM, Fronza BM, Hadis M, Palin WM, Lima AF. Chemistry of novel and contemporary resin-based dental adhesives. J Mech Behav Biomed Mater 2020; 110:103875. [PMID: 32957185 DOI: 10.1016/j.jmbbm.2020.103875] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/12/2020] [Accepted: 05/20/2020] [Indexed: 12/23/2022]
Abstract
The chemistry of resin-based dental adhesives is critical for its interaction with dental tissues and long-term bonding stability. Changes in dental adhesives composition influences the materials' key physical-chemical properties, such as rate and degree of conversion, water sorption, solubility, flexural strength and modulus, and cohesive strength and improves the biocompatibility to dental tissues. Maintaining a suitable reactivity between photoinitiators and monomers is important for optimal properties of adhesive systems, in order to enable adequate polymerisation and improved chemical, physical and biological properties. The aim of this article is to review the current state-of-the-art of dental adhesives, and their chemical composition and characteristics that influences the polymerisation reaction and subsequent materials properties and performance.
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Affiliation(s)
- Diogo Dressano
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av Limeira, 901 Mail Box 52, Piracicaba, Sao Paulo, 13414-903, Brazil.
| | - Marcos V Salvador
- Dental Research Division, Paulista University, Sao Paulo, Rua Doutor Bacelar, 1212, CEP: 04026-002, Brazil.
| | | | - Giselle Maria Marchi
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av Limeira, 901 Mail Box 52, Piracicaba, Sao Paulo, 13414-903, Brazil.
| | - Bruna M Fronza
- Department of Biomaterials and Oral Biology, University of São Paulo, 2227 Prof. Lineu Prestes Ave, 05508-000, São Paulo, SP, Brazil.
| | - Mohammed Hadis
- Dental Materials Science, Birmingham Dental School and Hospital, College of Medical and Dental Science, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK.
| | - William M Palin
- Dental Materials Science, Birmingham Dental School and Hospital, College of Medical and Dental Science, University of Birmingham, 5 Mill Pool Way, Edgbaston, Birmingham, B5 7EG, UK.
| | - Adriano Fonseca Lima
- Dental Research Division, Paulista University, Sao Paulo, Rua Doutor Bacelar, 1212, CEP: 04026-002, Brazil.
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Dry-bonding to dentin using alternative conditioners based on iron-containing solutions or nitric acid. J Mech Behav Biomed Mater 2019; 94:238-248. [PMID: 30927591 DOI: 10.1016/j.jmbbm.2019.03.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 02/06/2019] [Accepted: 03/17/2019] [Indexed: 11/21/2022]
Abstract
OBJECTIVES To evaluate the effect of experimental conditioners (10-3 solution - 10-3, 6.8% ferric oxalate - FOX, and 1.4% nitric acid - NI) on dentin elastic modulus, flexural strength, bond strength, failure mode, and adhesive interface morphology of two etch-and-rinse adhesives (XP Bond, Dentsply or One-Step, Bisco) applied on etched dry dentin. METHODS Sound human third molars were used for the microtensile bond strength test (n = 8), performed at 24 h and after one year of water storage. Failure modes were evaluated by scanning electron microscopy. Dentin bonding interface was analyzed by confocal laser scanning microscopy (n = 3). Adhesive systems were applied on phosphoric acid-etched, wet (positive control) and dry (negative control) dentin, and on etched and dry dentin previously treated with 10-3 (15s), FOX (60s), or NI (15s). Bovine dentin bars (n = 15) were immersed into the conditioning solutions and subjected to a three-point bending test. RESULTS XP Bond + 10-3 or NI resulted in lower bond strength than phosphoric acid. One-Step + 10-3 or NI resulted in bond strengths equivalent to the positive control. Experimental conditioners presented no bond strength reduction after one year, regardless of the bonding agent tested. One-Step resulted in more adhesive failures than XP Bond at 24 h, and mixed failures increased after storage. All experimental conditioners promoted hybridization and resin tags formation, except FOX. Dentin elastic modulus was not affected by the conditioners, whereas flexural strength was significantly reduced by FOX. CONCLUSIONS Adequate and stable dentin bonds were achieved when the bonding agents were applied on 10-3 or NI-treated dentin. None of the experimental conditioners reduced dentin elastic modulus, but dentin flexural strength was significantly reduced by FOX-conditioning.
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Parthasarathy R, Misra A, Song L, Ye Q, Spencer P. Structure-property relationships for wet dentin adhesive polymers. Biointerphases 2018; 13:061004. [PMID: 30558430 PMCID: PMC6296910 DOI: 10.1116/1.5058072] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 12/23/2022] Open
Abstract
Dentin adhesive systems for composite tooth restorations are composed of hydrophilic/hydrophobic monomers, solvents, and photoinitiators. The adhesives undergo phase separation and concomitant compositional change during their application in the wet oral environment; phase separation compromises the quality of the hybrid layer in the adhesive/dentin interface. In this work, the adhesive composition in the hybrid layer can be represented using the phase boundaries of a ternary phase diagram for the hydrophobic monomer/hydrophilic monomer/water system. The polymer phases, previously unaccounted for, play an important role in determining the mechanical behavior of the bulk adhesive, and the chemomechanical properties of the phases are intimately related to the effects produced by differences in the hydrophobic-hydrophilic composition. As the composition of the polymer phases varies from hydrophobic-rich to hydrophilic-rich, the amount of the adsorbed water and the nature of polymer-water interaction vary nonlinearly and strongly correlate with the change in elastic moduli under wet conditions. The failure strain, loss modulus, and glass transition temperature vary nonmonotonically with composition and are explained based upon primary and secondary transitions observed in dynamic mechanical testing. Due to the variability in composition, the assignment of mechanical properties and the choice of suitable constitutive models for polymer phases in the hybrid layer are not straightforward. This work investigates the relationship between composition and chemomechanical properties of the polymer phases formed on the water-adhesive phase boundary using quasistatic and dynamic mechanical testing, mass transfer experiments, and vibrational spectroscopy.
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Affiliation(s)
- Ranganathan Parthasarathy
- Department of Civil and Architectural Engineering, Tennessee State University, 3500 John A Merritt Blvd, Nashville, Tennessee 37209
| | - Anil Misra
- Department of Civil and Environmental Engineering, Institute for Bioengineering Research, University of Kansas, 5104B Learned Hall, 1530 W 15th Street, Lawrence, Kansas 66045
| | - Linyong Song
- Institute for Bioengineering Research, University of Kansas, 5104A Learned Hall, 1530 W 15th Street, Lawrence, Kansas 66045
| | - Qiang Ye
- Institute for Bioengineering Research, University of Kansas, 5101E Learned Hall, 1530 W 15th Street, Lawrence, Kansas 66045
| | - Paulette Spencer
- Department of Mechanical Engineering, Institute for Bioengineering Research, University of Kansas, 3111 Learned Hall, 1530 W 15th Street, Lawrence, Kansas 66045
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Li Y, Hu X, Xia Y, Ji Y, Ruan J, Weir MD, Lin X, Nie Z, Gu N, Masri R, Chang X, Xu HHK. Novel magnetic nanoparticle-containing adhesive with greater dentin bond strength and antibacterial and remineralizing capabilities. Dent Mater 2018; 34:1310-1322. [PMID: 29935766 PMCID: PMC6103821 DOI: 10.1016/j.dental.2018.06.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Revised: 05/22/2018] [Accepted: 06/01/2018] [Indexed: 10/28/2022]
Abstract
OBJECTIVES A nanoparticle-doped adhesive that can be controlled with magnetic forces was recently developed to deliver drugs to the pulp and improve adhesive penetration into dentin. However, it did not have bactericidal and remineralization abilities. The objectives of this study were to: (1) develop a magnetic nanoparticle-containing adhesive with dimethylaminohexadecyl methacrylate (DMAHDM), amorphous calcium phosphate nanoparticles (NACP) and magnetic nanoparticles (MNP); and (2) investigate the effects on dentin bond strength, calcium (Ca) and phosphate (P) ion release and anti-biofilm properties. METHODS MNP, DMAHDM and NACP were mixed into Scotchbond SBMP at 2%, 5% and 20% by mass, respectively. Two types of magnetic nanoparticles were used: acrylate-functionalized iron nanoparticles (AINPs); and iron oxide nanoparticles (IONPs). Each type was added into the resin at 1% by mass. Dentin bonding was performed with a magnetic force application for 3min, provided by a commercial cube-shaped magnet. Dentin shear bond strengths were measured. Streptococcus mutans biofilms were grown on resins, and metabolic activity, lactic acid and colony-forming units (CFU) were determined. Ca and P ion concentrations in, and pH of biofilm culture medium were measured. RESULTS Magnetic nanoparticle-containing adhesive using magnetic force increased the dentin shear bond strength by 59% over SBMP Control (p<0.05). Adding DMAHDM and NACP did not adversely affect the dentin bond strength (p>0.05). The adhesive with MNP+DMAHDM+NACP reduced the S. mutans biofilm CFU by 4 logs. For the adhesive with NACP, the biofilm medium became a Ca and P ion reservoir. The biofilm culture medium of the magnetic nanoparticle-containing adhesive with NACP had a safe pH of 6.9, while the biofilm medium of commercial adhesive had a cariogenic pH of 4.5. SIGNIFICANCE Magnetic nanoparticle-containing adhesive with DMAHDM and NACP under a magnetic force yielded much greater dentin bond strength than commercial control. The novel adhesive reduced biofilm CFU by 4 logs and increased the biofilm pH from a cariogenic pH 4.5-6.9, and therefore is promising to enhance the resin-tooth bond, strengthen tooth structures, and suppress secondary caries at the restoration margins.
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Affiliation(s)
- Yuncong Li
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China; Department of Prosthodontics, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China; Department of Advanced Oral Sciences & Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Xiaoyi Hu
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China; Department of Oral Maxillofacial Surgery, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Yang Xia
- Department of Advanced Oral Sciences & Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Yadong Ji
- Department of Advanced Oral Sciences & Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Jianping Ruan
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China
| | - Michael D Weir
- Department of Advanced Oral Sciences & Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA
| | - Xiaoying Lin
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Zhihong Nie
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Ning Gu
- Jiangsu Key Laboratory for Biomaterials and Devices, School of Biological Science and Medical Engineering, Southeast University, Nanjing, Jiangsu 210096, China
| | - Radi Masri
- Department of Advanced Oral Sciences & Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA.
| | - Xiaofeng Chang
- Clinical Research Center of Shaanxi Province for Dental and Maxillofacial Diseases, Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an, Shaanxi 710004, China.
| | - Hockin H K Xu
- Department of Advanced Oral Sciences & Therapeutics, University of Maryland School of Dentistry, Baltimore, MD 21201, USA; Center for Stem Cell Biology and Regenerative Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; University of Maryland Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
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Lapinska B, Klimek L, Sokolowski J, Lukomska-Szymanska M. Dentine Surface Morphology after Chlorhexidine Application-SEM Study. Polymers (Basel) 2018; 10:polym10080905. [PMID: 30960830 PMCID: PMC6403839 DOI: 10.3390/polym10080905] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 08/01/2018] [Accepted: 08/10/2018] [Indexed: 11/16/2022] Open
Abstract
Chlorhexidine (CHX) is a widely known and a very popular antibacterial agent that decreases the level of cariogenic bacteria. CHX applied on the cavity surface of dentine may influence adhesive bond strength. The aim of the study was to evaluate the dentine surface after different chlorhexidine digluconate (CHG) application protocols. Different CHG application protocols were introduced. A concentration of 0.2% or 2.0% CHG was applied on the etched or unetched dentine surface for 15 or 30 s, then water rinsed or drained. Scanning electron microscopy (SEM) observations and energy disperse spectrometer (EDS) analysis of the dentine surfaces were performed. The application of 0.2% CHG for 15 s, followed by draining, on either etched or unetched dentine surface effectively removed the smear layer, leaving the surface enriched with CHG deposits. Conclusions: The concentration of CHG and its application time influenced the amount of CHG deposits and the degree of smear layer removal from the dentine surface.
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Affiliation(s)
- Barbara Lapinska
- Department of General Dentistry, Medical University of Lodz, 92-213 Lodz, Poland.
| | - Leszek Klimek
- Department of Dental Technology, Medical University of Lodz, 92-213 Lodz, Poland.
| | - Jerzy Sokolowski
- Department of General Dentistry, Medical University of Lodz, 92-213 Lodz, Poland.
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Stape THS, Tjäderhane L, Abuna G, Sinhoreti MAC, Martins LRM, Tezvergil-Mutluay A. Optimization of the etch-and-rinse technique: New perspectives to improve resin–dentin bonding and hybrid layer integrity by reducing residual water using dimethyl sulfoxide pretreatments. Dent Mater 2018; 34:967-977. [DOI: 10.1016/j.dental.2018.03.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/30/2017] [Accepted: 03/23/2018] [Indexed: 11/16/2022]
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Pucci CR, Gu LS, Zhang HY, Song Q, Xia VW, Davis LB, de Souza Andrade D, Mazzoni A, Breschi L, Pashley DH, Tay FR, Niu LN. Water-associated attributes in the contemporary dentin bonding milieu. J Dent 2018; 74:79-89. [PMID: 29702152 DOI: 10.1016/j.jdent.2018.04.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 04/19/2018] [Accepted: 04/23/2018] [Indexed: 12/15/2022] Open
Abstract
OBJECTIVES The water-associated attributes of resin-dentin interfaces created by contemporary adhesives are important determinants of bond integrity and stability. In the present work, these attributes were estimated from the perspectives of causality, to examine the behavior of the first and most-recently launched versions of universal adhesives when applied in either the etch-and-rinse mode or the self-etch mode. METHODS The immediate cause of interfacial permeability and the time-dependent cause of water sorption were investigated in conjunction with the intermediate effect of interface degradation and the more long-term effect of loss of mechanical strength, before and after thermomechanical cycling. The results were compared with control etch-and-rinse and self-etch adhesives. RESULTS Although the introduction of this new class of universal adhesives has brought forth significant changes to the dental adhesion arena, including more application options, reduced bonding armamentarium and increased user friendliness, the water-associated attributes that are critical for making resin-dentin bonds more durable to environmental challenges and less susceptible to degradation have remained unchanged at large, when compared with benchmarks established by former classes of adhesives. CONCLUSION It appears that the current trend of adhesive development has brought forth significant changes but lacks the vigor that demarcates progress and technological sublimity. CLINICAL SIGNIFICANCE The advent of the user friendly universal adhesives has brought forth significant changes to the dental adhesion arena. However, the elements that are critical for making resin-dentin bonds more durable to environmental challenges and less susceptible to degradation have remained unchanged at large.
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Affiliation(s)
- Cesar R Pucci
- Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University UNESP São Jose dos Campos, São Paulo, Brazil
| | - Li-Sha Gu
- Department of Operative Dentistry and Endodontics, Guanghua School of Stomatology & Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Hong-Yun Zhang
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Qun Song
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, School of Stomatology, The Fourth Military Medical University, Xi'an, China
| | - Veronica Wang Xia
- Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA, USA
| | - Linsey B Davis
- Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA, USA
| | - Danilo de Souza Andrade
- Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University UNESP São Jose dos Campos, São Paulo, Brazil
| | - Annalisa Mazzoni
- Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna - Alma Mater Studiorum, Bologna, Italy
| | - Lorenzo Breschi
- Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna - Alma Mater Studiorum, Bologna, Italy
| | - David H Pashley
- Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA, USA
| | - Franklin R Tay
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, School of Stomatology, The Fourth Military Medical University, Xi'an, China; Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA, USA.
| | - Li-Na Niu
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, School of Stomatology, The Fourth Military Medical University, Xi'an, China; Department of Endodontics, The Dental College of Georgia, Augusta University, Augusta, GA, USA; The Third Affiliated Hospital of Xinxiang Medical University, Xinxiang, Hena, China.
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Mehtälä P, Pashley D, Tjäderhane L. Effect of dimethyl sulfoxide on dentin collagen. Dent Mater 2017; 33:915-922. [DOI: 10.1016/j.dental.2017.04.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 02/16/2017] [Accepted: 04/25/2017] [Indexed: 11/28/2022]
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Huang XQ, Pucci CR, Luo T, Breschi L, Pashley DH, Niu LN, Tay FR. No-waiting dentine self-etch concept-Merit or hype. J Dent 2017; 62:54-63. [PMID: 28506642 DOI: 10.1016/j.jdent.2017.05.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 05/10/2017] [Accepted: 05/11/2017] [Indexed: 10/19/2022] Open
Abstract
OBJECTIVE A recently-launched universal adhesive, G-Premio Bond, provides clinicians with the alternative to use the self-etch technique for bonding to dentine without waiting for the adhesive to interact with the bonding substrate (no-waiting self-etch; Japanese brochure), or after leaving the adhesive undisturbed for 10s (10-s self-etch; international brochure). The present study was performed to examine in vitro performance of this new universal adhesive bonded to human coronal dentine using the two alternative self-etch modes. METHODS One hundred and ten specimens were bonded using two self-etch application modes and examined with or without thermomechanical cycling (10,000 thermal cycles and 240,000 mechanical cycles) to simulate one year of intraoral functioning. The bonded specimens were sectioned for microtensile bond testing, ultrastructural and nanoleakage examination using transmission electron microscopy. Changes in the composition of mineralised dentine after adhesive application were examined using Fourier transform infrared spectroscopy. RESULTS Both reduced application time and thermomechanical cycling resulted in significantly lower bond strengths, thinner hybrid layers, and significantly more extensive nanoleakage after thermomechanical cycling. Using the conventional 10-s application time improved bonding performance when compared with the no-waiting self-etch technique. Nevertheless, nanoleakage was generally extensive under all testing parameters employed for examining the adhesive. CONCLUSION Although sufficient bond strength to dentine may be achieved using the present universal adhesive in the no-waiting self-etch mode that does not require clinicians to wait prior to polymerisation of the adhesive, this self-etch concept requires further technological refinement before it can be recommended as a clinical technique. CLINICAL SIGNIFICANCE Although the surge for cutting application time to increase user friendliness remains the most frequently sought conduit for advancement of dentine bonding technology, the use of the present universal adhesive in the no-waiting self-etch mode may not represent the best use of the adhesive.
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Affiliation(s)
- Xue-Qing Huang
- Department of Prosthodontics, Guanghua School and Hospital of Stomatology & Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, PR China
| | - César R Pucci
- Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University UNESP São Jose dos Campos, São Paulo, Brazil
| | - Tao Luo
- Key Laboratory of Oral Medicine, Guangzhou Institute of Oral Disease, Stomatology Hospital of Guangzhou Medical University, Guangzhou, Guangdong, PR China
| | - Lorenzo Breschi
- Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna - Alma Mater Studiorum, Bologna, Italy
| | - David H Pashley
- College of Graduate Studies, Augusta University, Augusta, GA, USA
| | - Li-Na Niu
- State Key Laboratory of Military Stomatology & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Oral Diseases, School of Stomatology, The Fourth Military Medical University, Xi'an, Shaanxi, PR China.
| | - Franklin R Tay
- College of Graduate Studies, Augusta University, Augusta, GA, USA.
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Degradation of resin-dentine bond of different adhesive systems to primary and permanent dentine. Eur Arch Paediatr Dent 2017; 18:113-118. [PMID: 28271448 DOI: 10.1007/s40368-017-0282-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 02/25/2017] [Indexed: 01/01/2023]
Abstract
AIM To evaluate the water storage degradation of resin-dentine bonds of different adhesive systems to primary and permanent human dentine. METHODS Flat occlusal human dentine surfaces of 15 primary molars and 15 permanent molars were randomly assigned according to adhesive systems: Adper Single Bond 2; Clearfil SE Bond and One Up Bond F Plus. After bonding procedures, the adhesives were applied according to the manufacturers' instructions and composite resin blocks were built. Restored teeth were sectioned rendering rectangular sticks (RS) (0.4 mm2). The RS were submitted to microtensile bond strength (µTBS) test according to the water storage time: 24 h, 1-year, and 2-years. Mean µTBS values were analysed by three-way analysis of variance (mixed design) and Tukey post hoc test (α = 0.05). The failure mode was analysed at 400× magnification. RESULTS All three factors isolated showed significant influences on µTBS, as did the cross-product interactions between material vs. storage time (p = 0.01) and substrate vs. storage time (p = 0.002). Bond strength means to primary dentine were lower than to permanent dentine (34.7 ± 10.1 and 45.8 ± 12.9 mPa, respectively) after 2-years of water storage. The one-step self-etch adhesive (One Up Bond F Plus) showed less stable bond strength after 2-years of water storage. CONCLUSION The resin-dentine bond of primary teeth was more prone to degradation over time compared to permanent dentine.
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Can long-term dentine bonding created in real life be forecasted by parameters established in the laboratory? Sci Rep 2016; 6:37799. [PMID: 27886272 PMCID: PMC5122885 DOI: 10.1038/srep37799] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 11/02/2016] [Indexed: 11/08/2022] Open
Abstract
Tooth-coloured plastic dental fillings secured by adhesives to tooth structures are widely used to fix decayed teeth. Whereas laboratory tests demonstrate rapid deterioration of the ability of the adhesives to stick to dentine, clinical studies show that these fillings are relatively durable. This discrepancy suggests that the parameters used for simulating bond degradation in the laboratory setting do not correlate well with clinical outcomes. The present study examined the long-term tensile bond strength of resin composite fillings performed in real life and under different laboratory-simulated bonding conditions to identify parameters that may be used to forecast the durability of adhesive bonds created in dentine. Fillings placed in vivo were subjected to different periods of intraoral function. In vitro specimens were bonded based on whether simulated pulpal pressure (SPP) or thermomechanical cycling was implemented, and how long the completed fillings were stored in water. Thermomechanical cycling used in combination with long-term water ageing are useful in forecasting the decline in strength of resin-dentine bonds created in vivo. These parameters should be adopted for future evaluations. Conversely, the use of SPP does not appear to be a significant parameter in the simulation of long-term clinical deterioration of bond integrity.
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Cross-linked dry bonding: A new etch-and-rinse technique. Dent Mater 2016; 32:1124-32. [PMID: 27431091 DOI: 10.1016/j.dental.2016.06.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 03/16/2016] [Accepted: 06/22/2016] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To determine if acid-etched, cross-linked dentin can be dehydrated without lowering bond strength below that of cross-linked wet-bonded dentin in vitro. METHODS Using extracted human third molars, control acid-etched dentin was bonded with Single Bond Plus, using either the wet- or dry-bonding technique. Experimental acid-etched dentin was treated with 5mass% grape seed extract (GSE) in different solvents for 1min before undergoing wet vs dry resin-dentin bonding with Single Bond Plus. Completely demineralized dentin beams were treated with 5% GSE for 0, 1 or 10min, before measuring stiffness by 3-point flexure. Other completely demineralized beams were treated similarly and then incubated in buffer for 1 week to measure the collagen solubilization by endogenous dentin proteases. RESULTS 24h microtensile bond strengths (μTBS) in wet and dry controls were 53.5±3.6 and 9.4±1.8MPa, respectively (p<0.05). 5% GSE in water gave μTBS of 53.7±3.4 and 39.1±9.7MPa (p<0.05), respectively, while 5% GSE in ethanol gave μTBS of 51.2±2.3 and 35.3±2.0MPa (p<0.05). 5% GSE in 5% EtOH/95% water gave wet and dry μTBS of 53.0±2.3 and 55.7±5.1MPa (p>0.05). Cross-linking demineralized dentin with 5% GSE increased stiffness of dentin and decreased collagen degradation (p<0.05). SIGNIFICANCE 5% GSE pretreatment of acid-etched dentin for 1min permits the dentin to be completely air-dried without lowering bond strength.
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Ge X, Ye Q, Song L, Laurence JS, Misra A, Spencer P. Probing the dual function of a novel tertiary amine compound in dentin adhesive formulations. Dent Mater 2016; 32:519-28. [PMID: 26764171 DOI: 10.1016/j.dental.2015.12.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 10/27/2015] [Accepted: 12/07/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVES A novel tertiary amine compound containing three methacrylate-urethane groups was synthesized for application in dentin adhesives. The synthesis, photopolymerization kinetics, and leaching were examined in an earlier study using this novel compound as the co-initiator (0.5 and 1.75wt% based on the total resin mass). The objective of this work was to investigate the potential of TUMA (8-(2-(((2-(methacryloyloxy)ethyl)carbamoyl)oxy)propyl)-6,10-dimethyl-4,12-dioxo-5,11-dioxa-3,8,13-triazapentadecane-1,15-diyl bis(2-methylacrylate)) to serve simultaneously as a co-initiator and co-monomer (15-45wt% based on the total resin mass) in dentin adhesive formulations. The polymerization kinetics, water sorption and dynamic mechanical properties of these novel formulations were determined. MATERIALS AND METHOD The monomer system contained Bisphenol A glycerolate dimethacrylate (BisGMA), 2-hydroxyethylmethacrylate (HEMA) and TUMA (synthesized in our lab) at the mass ratio of 45/(55-x)/x. Two photoinitiator (PI) systems were compared. One initiator system contains three components: camphorquinone (CQ), diphenyliodonium hexafluorophosphate (DPIHP) and ethyl-4-(dimethylamino) benzoate (EDMAB) and the second initiator system contains CQ and DPIHP. The control adhesive formulations are: C0-3: HEMA/BisGMA 45/55 (w/w) and 3-component PI and C0-2: HEMA/BisGMA 45/55 (w/w) and 2-component PI. These controls were used as a comparison to the experimental adhesive resins (Ex-3 or Ex-2), in which x represents the weight percentage of synthesized co-monomer (TUMA) to replace part of BisGMA. The control and experimental adhesive formulations were photo-polymerized and compared with regard to the degree of conversion (DC), polymerization rate (Rp), water sorption and dynamic mechanical analysis (DMA) under both dry and wet conditions. RESULTS C0-3 and Ex-3 formulations had similar DC, while the DC of Ex-2 formulation was higher than C0-2. The DC was similar when comparing the two- component with the three-component photoinitiator system when TUMA was used at the same concentration. DMA under dry conditions shows higher rubbery storage modulus for all experimental formulations, while storage modulus at rubbery region under wet conditions was decreased as compared with control (C0-3). There was no statistically significant difference for the DMA results under both dry and wet conditions when comparing two- and three-component initiator systems with the same TUMA concentration. SIGNIFICANCE The newly synthesized TUMA could serve simultaneously as a co-monomer and co-initiator in the absence of commercial co-initiator. This study provides information for the future development of new co-monomer/co-initiator for dentin adhesives and dental composites.
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Affiliation(s)
- Xueping Ge
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA
| | - Qiang Ye
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA.
| | - Linyong Song
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA
| | - Jennifer S Laurence
- Department of Pharmaceutical Chemistry, University of Kansas, 2095 Constant Ave, Lawrence, KS 66047-3729, USA
| | - Anil Misra
- Department of Civil Engineering, University of Kansas, Lawrence, KS, USA
| | - Paulette Spencer
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA; Department of Mechanical Engineering, University of Kansas, Lawrence, KS, USA
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Stape THS, Tjäderhane L, Marques MR, Aguiar FHB, Martins LRM. Effect of dimethyl sulfoxide wet-bonding technique on hybrid layer quality and dentin bond strength. Dent Mater 2015; 31:676-83. [DOI: 10.1016/j.dental.2015.03.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 11/14/2014] [Accepted: 03/20/2015] [Indexed: 10/23/2022]
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19
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Agee KA, Prakki A, Abu-Haimed T, Naguib GH, Nawareg MA, Tezvergil-Mutluay A, Scheffel DLS, Chen C, Jang SS, Hwang H, Brackett M, Grégoire G, Tay FR, Breschi L, Pashley DH. Water distribution in dentin matrices: bound vs. unbound water. Dent Mater 2015; 31:205-16. [PMID: 25612786 DOI: 10.1016/j.dental.2014.12.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 12/08/2014] [Accepted: 12/09/2014] [Indexed: 12/23/2022]
Abstract
OBJECTIVE This work measured the amount of bound versus unbound water in completely-demineralized dentin. METHODS Dentin beams prepared from extracted human teeth were completely demineralized, rinsed and dried to constant mass. They were rehydrated in 41% relative humidity (RH), while gravimetrically measuring their mass increase until the first plateau was reached at 0.064 (vacuum) or 0.116 gH2O/g dry mass (Drierite). The specimens were then exposed to 60% RH until attaining the second plateau at 0.220 (vacuum) or 0.191 gH2O/g dry mass (Drierite), and subsequently exposed to 99% RH until attaining the third plateau at 0.493 (vacuum) or 0.401 gH2O/g dry mass (Drierite). RESULTS Exposure of the first layer of bound water to 0% RH for 5 min produced a -0.3% loss of bound water; in the second layer of bound water it caused a -3.3% loss of bound water; in the third layer it caused a -6% loss of bound water. Immersion in 100% ethanol or acetone for 5 min produced a 2.8 and 1.9% loss of bound water from the first layer, respectively; it caused a -4 and -7% loss of bound water in the second layer, respectively; and a -17 and -23% loss of bound water in the third layer. Bound water represented 21-25% of total dentin water. Chemical dehydration of water-saturated dentin with ethanol/acetone for 1 min only removed between 25 and 35% of unbound water, respectively. SIGNIFICANCE Attempts to remove bound water by evaporation were not very successful. Chemical dehydration with 100% acetone was more successful than 100% ethanol especially the third layer of bound water. Since unbound water represents between 75 and 79% of total matrix water, the more such water can be removed, the more resin can be infiltrated.
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Affiliation(s)
- Kelli A Agee
- Department of Oral Biology, College of Dental Medicine, Georgia Regents University, Augusta, GA 30912-1129, USA
| | - Anuradha Prakki
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - Tariq Abu-Haimed
- Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Ghada H Naguib
- Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Manar Abu Nawareg
- Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Arzu Tezvergil-Mutluay
- Adhesive Dentistry Research Group, Institute of Dentistry, University of Turku, Turku, Finland
| | - Debora L S Scheffel
- Department of Orthodontics and Pediatric Dentistry, Araraquara School of Dentistry, UNESP-UnivEstadualPaulista, Araraquara, SP, Brazil
| | - Chen Chen
- Department of Endodontology and Oral Mucosa, Jiangsu Key Laboratory of Oral Disease, Nanjing Medical University, Affiliated Hospital of Stomatology, Nanjing, Jiangsu, China
| | - Seung Soon Jang
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Hyea Hwang
- School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Martha Brackett
- Department of Oral Biology, College of Dental Medicine, Georgia Regents University, Augusta, GA 30912-1129, USA
| | - Geneviéve Grégoire
- Department of Biomaterials, Faculty of Odontology, University of Toulouse III, Toulouse, France
| | - Franklin R Tay
- Department of Oral Biology, College of Dental Medicine, Georgia Regents University, Augusta, GA 30912-1129, USA
| | - Lorenzo Breschi
- Department of Biomedical and Neuromotor Sciences, DIBINEM, University of Bologna and IGM-CNR, Unit of Bologna, Bologna, Italy
| | - David H Pashley
- Department of Oral Biology, College of Dental Medicine, Georgia Regents University, Augusta, GA 30912-1129, USA.
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Dailing EA, Lewis SH, Barros MD, Stansbury JW. Construction of monomer-free, highly crosslinked, water-compatible polymers. J Dent Res 2014; 93:1326-31. [PMID: 25248612 DOI: 10.1177/0022034514552490] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Polymeric dental adhesives require the formation of densely crosslinked network structures to best ensure mechanical strength and durability in clinical service. Monomeric precursors to these materials typically consist of mixtures of hydrophilic and hydrophobic components that potentially undergo phase separation in the presence of low concentrations of water, which is detrimental to material performance and has motivated significant investigation into formulations that reduce this effect. We have investigated an approach to network formation based on nanogels that are dispersed in inert solvent and directly polymerized into crosslinked polymers. Monomers of various hydrophilic or hydrophobic characteristics were copolymerized into particulate nanogels bearing internal and external polymerizable functionality. Nanogel dispersions were stable at high concentrations in acetone or, with some exceptions, in water and produced networks with a wide range of mechanical properties. Networks formed rapidly upon light activation and reached high conversion with extremely low volumetric shrinkage. Prepolymerizing monomers into reactive nanostructures significantly changes how hydrophobic materials respond to water compared with networks obtained from polymerizations involving free monomer. The modulus of fully hydrated networks formed solely from nanogels was shown to equal or exceed the modulus in the dry state for networks based on nanogels containing a hydrophobic dimethacrylate and hydrophilic monomethacrylate, a result that was not observed in a hydroxyethyl methacrylate (HEMA) homopolymer or in networks formed from nanogels copolymerized with HEMA. These results highlight the unique approach to network development from nanoscale precursors and properties that have direct implications in functional dental materials.
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Affiliation(s)
- E A Dailing
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, USA
| | - S H Lewis
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, Aurora, CO, USA
| | - M D Barros
- Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, Aurora, CO, USA
| | - J W Stansbury
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, USA Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, Aurora, CO, USA
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Abedin F, Ye Q, Good HJ, Parthasarathy R, Spencer P. Polymerization- and solvent-induced phase separation in hydrophilic-rich dentin adhesive mimic. Acta Biomater 2014; 10:3038-47. [PMID: 24631658 DOI: 10.1016/j.actbio.2014.03.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 02/12/2014] [Accepted: 03/03/2014] [Indexed: 11/30/2022]
Abstract
Current dental resin undergoes phase separation into hydrophobic-rich and hydrophilic-rich phases during infiltration of the over-wet demineralized collagen matrix. Such phase separation undermines the integrity and durability of the bond at the composite/tooth interface. This study marks the first time that the polymerization kinetics of model hydrophilic-rich phase of dental adhesive has been determined. Samples were prepared by adding varying water content to neat resins made from 95 and 99 wt.% hydroxyethylmethacrylate and 5 and 1 wt.% (2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl1]-propane prior to light curing. Viscosity of the formulations decreased with increased water content. The photopolymerization kinetics study was carried out with a time-resolved Fourier transform infrared spectrometer. All of the samples exhibited two-stage polymerization behavior which has not been reported previously for dental resin formulation. The lowest secondary rate maxima were observed for water contents of 10-30 wt.%. Differential scanning calorimetry (DSC) showed two glass transition temperatures for the hydrophilic-rich phase of dental adhesive. The DSC results indicate that the heterogeneity within the final polymer structure decreased with increasing water content. The results suggest a reaction mechanism involving both polymerization-induced phase separation and solvent-induced phase separation for the model hydrophilic-rich phase of dental resin.
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Affiliation(s)
- Farhana Abedin
- Bioengineering Research Center, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA; Bioengineering Graduate Program, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Qiang Ye
- Bioengineering Research Center, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA.
| | - Holly J Good
- Bioengineering Research Center, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Ranganathan Parthasarathy
- Bioengineering Research Center, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Paulette Spencer
- Bioengineering Research Center, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA; Department of Mechanical Engineering, University of Kansas, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
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Cavalheiro JP, Tonetto MR, Borges ÁH, Bandéca MC, dos Santos RSS, de Campos EA, Saad JRC, Dantas AAR, de Andrade MF. Marginal adaptation of class V restorations with current-generation dentin-bonding agents: effect of different dentin surface treatments. J Contemp Dent Pract 2014; 15:331-5. [PMID: 25307816 DOI: 10.5005/jp-journals-10024-1538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study sought to assess the use of chlorhexidine with several excipients as a dentin surface treatment and its effect on marginal adaptation of class V restorations with current-generation dentin bonding agents. A total of 120 human third molars were selected and allocated into 12 groups, with standardized buccal class V restorations randomly divided into preconditioned dentin rinsed with: water; water + chlorhexidine; ethanol; or ethanol + chlorhexidine. After rinsing of dentin (previously conditioned with 35% phosphoric acid) with the test solutions, the Adper single bond 2, prime and bond 2.1, and Excite bonding systems were applied randomly. Restorations were performed with Filtek™ Z350 XT composite resin. The resulting specimens were subjected to thermal and mechanical load cycling. Quantitative analysis of marginal adaptation was performed on epoxy replicas by means of scanning electron microscopy. Results were assessed by means of the Kruskal-Wallis test (percentages of continuous margins) and Wilcoxon test (differences between percentages of continuous margins before and after thermal cycling and mechanical loading), at a significance level of p < 0.05. Outcomes in the chlorhexidine-treated groups were not superior to those obtained with other treatments.
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Affiliation(s)
| | - Mateus Rodrigues Tonetto
- Professor, Department of Postgraduation in Integrated Dental Sciences University of Cuiaba, MT, Brazil
| | - Álvaro Henrique Borges
- Professor, Department of Postgraduation in Dentistry, CEUMA University, São Luis, MA, Brazil, e-mail:
| | - Matheus Coelho Bandéca
- Professor, Department of Postgraduation in Dentistry, CEUMA University, São Luis, MA, Brazil
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Loguercio AD, Luque-Martinez I, Muñoz MA, Szesz AL, Cuadros-Sánchez J, Reis A. A comprehensive laboratory screening of three-step etch-and-rinse adhesives. Oper Dent 2014; 39:652-62. [PMID: 24720263 DOI: 10.2341/13-236] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES This study evaluated several bonding (microtensile bond strengths [μTBS], nanoleakage [NL], and in situ degree of conversion [ISDC] on dentin) and mechanical properties (ultimate tensile strength [UTS], degree of conversion [DC], water sorption [WS], and solubility [SL] in water) of four three-step etch-and-rinse adhesives in the short term. METHODS A total of 28 molars were used in this study. The dentin surfaces were bonded with the following adhesives: All-Bond 3 (ALB3); Fusion Duralink (FSDL); Optibond FL (OBFL), and Scotchbond Multi-Purpose (SBMP). After each adhesive-system application, composite resin build-ups were added. For bonding tests, specimens were sectioned in order to obtain bonded sticks. The sticks were divided to be tested for μTBS (0.5 mm/min), for NL (n=2), and ISDC (n=2). For NL, they were immersed in 50% silver nitrate and analyzed by scanning election microscopy. For ISDC, the hybrid layer was evaluated by micro-Raman spectroscopy. An hourglass-shaped matrix (UTS) or disk-shaped matrix (WS and SL) was filled with primer and adhesive (1:1 ratio) and light-polymerized. For UTS evaluation, the specimens were tested under tension. For WS and SL, specimens were desiccated and stored in distilled water to evaluate water diffusion kinetics over a 28-day period. The DC of the adhesives was evaluated by Fourier transformed infrared spectroscopy. The data from each test were analyzed by appropriate statistical methods. RESULTS OBFL resulted in the highest μTBS, lower NL, higher ISDC and DC, and higher UTS than other adhesives (p<0.05), as well as lower WS (similar to ALB3 and FSDL) and SL (similar to ALB3 and SBMP) (p>0.05). ALB3 showed a higher NL and the lowest DC value. FSDL showed the highest NL and SL and the lowest ISDC. SBMP showed the lowest pattern of WS (p<0.05)CONCLUSION: OBFL showed the best results in all the properties evaluated, and it can be considered the gold standard of the three-step etch-and-rinse adhesive systems.
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Song L, Ye Q, Ge X, Misra A, Laurence JS, Berrie CL, Spencer P. Synthesis and evaluation of novel dental monomer with branched carboxyl acid group. J Biomed Mater Res B Appl Biomater 2014; 102:1473-84. [PMID: 24596134 DOI: 10.1002/jbm.b.33126] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Revised: 01/23/2014] [Accepted: 02/18/2014] [Indexed: 11/07/2022]
Abstract
To enhance the water miscibility and increase the mechanical properties of dentin adhesives, a new glycerol-based monomer with vinyl and carboxylic acid, 4-((1,3-bis(methacryloyloxy)propan-2-yl)oxy)-2-methylene-4-oxobutanoic acid (BMPMOB), was synthesized and characterized. Dentin adhesive formulations containing 2-hydroxyethyl methacrylate (HEMA), 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (BisGMA), and BMPMOB were characterized with regard to real-time photopolymerization behavior, water sorption, dynamic mechanical analysis, and microscale three-dimensional internal morphologies and compared with HEMA/BisGMA controls. The experimental adhesive copolymers showed higher glass transition temperature and rubbery moduli, as well as improved water miscibility compared to the controls. The enhanced properties of the adhesive copolymers indicated that BMPMOB is a promising comonomer for dental restorative materials.
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Affiliation(s)
- Linyong Song
- Bioengineering Research Center, University of Kansas, Lawrence, Kansas, 66045; School of Chemistry and Chemical Engineering, Anhui University, Hefei, China
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Takahashi M, Nakajima M, Tagami J, Scheffel D, Carvalho R, Mazzoni A, Cadenaro M, Tezvergil-Mutluay A, Breschi L, Tjäderhane L, Jang S, Tay F, Agee K, Pashley D. The importance of size-exclusion characteristics of type I collagen in bonding to dentin matrices. Acta Biomater 2013; 9:9522-8. [PMID: 23928333 DOI: 10.1016/j.actbio.2013.07.037] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Revised: 07/11/2013] [Accepted: 07/30/2013] [Indexed: 10/26/2022]
Abstract
The mineral phase of dentin is located primarily within collagen fibrils. During development, bone or dentin collagen fibrils are formed first and then water within the fibril is replaced with apatite crystallites. Mineralized collagen contains very little water. During dentin bonding, acid-etching of mineralized dentin solubilizes the mineral crystallites and replaces them with water. During the infiltration phase of dentin bonding, adhesive comonomers are supposed to replace all of the collagen water with adhesive monomers that are then polymerized into copolymers. The authors of a recently published review suggested that dental monomers were too large to enter and displace water from collagen fibrils. If that were true, the endogenous proteases bound to dentin collagen could be responsible for unimpeded collagen degradation that is responsible for the poor durability of resin-dentin bonds. The current work studied the size-exclusion characteristics of dentin collagen, using a gel-filtration-like column chromatography technique, using dentin powder instead of Sephadex. The elution volumes of test molecules, including adhesive monomers, revealed that adhesive monomers smaller than ∼1000 Da can freely diffuse into collagen water, while molecules of 10,000 Da begin to be excluded, and bovine serum albumin (66,000 Da) was fully excluded. These results validate the concept that dental monomers can permeate between collagen molecules during infiltration by etch-and-rinse adhesives in water-saturated matrices.
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Ye Q, Parthasarathy R, Abedin F, Laurence JS, Misra A, Spencer P. Multivariate analysis of attenuated total reflection Fourier transform infrared (ATR FT-IR) spectroscopic data to confirm phase partitioning in methacrylate-based dentin adhesive. APPLIED SPECTROSCOPY 2013; 67:1473-1478. [PMID: 24359662 PMCID: PMC4023509 DOI: 10.1366/13-07179] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Water is ubiquitous in the mouths of healthy individuals and is a major interfering factor in the development of a durable seal between the tooth and composite restoration. Water leads to the formation of a variety of defects in dentin adhesives; these defects undermine the tooth-composite bond. Our group recently analyzed phase partitioning of dentin adhesives using high-performance liquid chromatography (HPLC). The concentration measurements provided by HPLC offered a more thorough representation of current adhesive performance and elucidated directions to be taken for further improvement. The sample preparation and instrument analysis using HPLC are, however, time-consuming and labor-intensive. The objective of this work was to develop a methodology for rapid, reliable, and accurate quantitative analysis of near-equilibrium phase partitioning in adhesives exposed to conditions simulating the wet oral environment. Analysis by Fourier transform infrared (FT-IR) spectroscopy in combination with multivariate statistical methods, including partial least squares (PLS) regression and principal component regression (PCR), were used for multivariate calibration to quantify the compositions in separated phases. Excellent predictions were achieved when either the hydrophobic-rich phase or the hydrophilic-rich phase mixtures were analyzed. These results indicate that FT-IR spectroscopy has excellent potential as a rapid method of detection and quantification of dentin adhesives that experience phase separation under conditions that simulate the wet oral environment.
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Affiliation(s)
- Qiang Ye
- University of Kansas, Bioengineering Research Center, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Ranganathan Parthasarathy
- University of Kansas, Bioengineering Research Center, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Farhana Abedin
- University of Kansas, Bioengineering Research Center, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Jennifer S. Laurence
- University of Kansas, Department of Pharmaceutical Chemistry, 2095 Constant Avenue, Lawrence, KS 66047-3729, USA
| | - Anil Misra
- University of Kansas, Bioengineering Research Center, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
- University of Kansas, Department of Civil Engineering, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
| | - Paulette Spencer
- University of Kansas, Bioengineering Research Center, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
- University of Kansas, Department of Mechanical Engineering, 1530 W. 15th Street, Lawrence, KS 66045-7609, USA
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Simões DMS, Basting RT, Amaral FLB, Turssi CP, França FMG. Influence of chlorhexidine and/or ethanol treatment on bond strength of an etch-and-rinse adhesive to dentin: an in vitro and in situ study. Oper Dent 2013; 39:64-71. [PMID: 23675741 DOI: 10.2341/12-486-l] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aim of this study was to evaluate the effect of a chlorhexidine and/or ethanol application on the bond strength of an etch-and-rinse, hydrophobic adhesive system either under in vitro aging or in situ cariogenic challenge. The dentin surface of 36 human third molars were flattened and allocated into four groups to be treated with chlorhexidine, ethanol, or chlorhexidine + ethanol or left unexposed to any solution (control) (n=9). Then, a resin composite restoration was made on the dentin surface and longitudinal sticks were obtained. Sticks from each tooth were assigned to three test conditions: stored in water in vitro for 24 hours, stored in water in vitro for 6 months, or worn in situ for 14 days. During in situ wear time, a high-cariogenic challenge condition was simulated. Specimens were tested for microtensile bond strength (μTBS). Multivariate analysis of variance and Tukey's test showed that chlorhexidine, ethanol, or chlorhexidine + ethanol did not affect the μTBS. The in vitro μTBS values were significantly lower for the specimens stored for 6 months than for those stored for 24 hours. Intermediate μTBS values were shown by the specimens worn in situ. Thus, use of chlorhexidine and/or ethanol was incapable of containing the degradation at the bond interface in the in vitro model. The in situ model was capable of reducing bond strength similarly to the in vitro/6 months model. Despite this, the in situ bond strength was still similar to that of the in vitro/24-hour model.
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Bohaty BS, Ye Q, Misra A, Sene F, Spencer P. Posterior composite restoration update: focus on factors influencing form and function. Clin Cosmet Investig Dent 2013; 5:33-42. [PMID: 23750102 PMCID: PMC3666491 DOI: 10.2147/ccide.s42044] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Indexed: 12/01/2022] Open
Abstract
Restoring posterior teeth with resin-based composite materials continues to gain popularity among
clinicians, and the demand for such aesthetic restorations is increasing. Indeed, the most common
aesthetic alternative to dental amalgam is resin composite. Moderate to large posterior composite
restorations, however, have higher failure rates, more recurrent caries, and increased frequency of
replacement. Investigators across the globe are researching new materials and techniques that will
improve the clinical performance, handling characteristics, and mechanical and physical properties
of composite resin restorative materials. Despite such attention, large to moderate posterior
composite restorations continue to have a clinical lifetime that is approximately one-half that of
the dental amalgam. While there are numerous recommendations regarding preparation design,
restoration placement, and polymerization technique, current research indicates that restoration
longevity depends on several variables that may be difficult for the dentist to control. These
variables include the patient’s caries risk, tooth position, patient habits, number of
restored surfaces, the quality of the tooth–restoration bond, and the ability of the
restorative material to produce a sealed tooth–restoration interface. Although clinicians
tend to focus on tooth form when evaluating the success and failure of posterior composite
restorations, the emphasis must remain on advancing our understanding of the clinical variables that
impact the formation of a durable seal at the restoration–tooth interface. This paper
presents an update of existing technology and underscores the mechanisms that negatively impact the
durability of posterior composite restorations in permanent teeth.
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Affiliation(s)
- Brenda S Bohaty
- Department of Pediatric Dentistry, University of Missouri-Kansas City School of Dentistry, Kansas City, MO, USA; ; Department of Pediatric Dentistry, Children's Mercy Hospital, Kansas City, MO, USA
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Luk A, Murthy N, Wang W, Rojas R, Kohn J. Study of nanoscale structures in hydrated biomaterials using small-angle neutron scattering. Acta Biomater 2012; 8:1459-68. [PMID: 22227373 DOI: 10.1016/j.actbio.2011.12.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Revised: 12/15/2011] [Accepted: 12/18/2011] [Indexed: 10/14/2022]
Abstract
Distribution of water in three classes of biomedically relevant and degradable polymers was investigated using small-angle neutron scattering. In semicrystalline polymers, such as poly(lactic acid) and poly(glycolic acid), water was found to diffuse preferentially into the non-crystalline regions. In amorphous polymers, such as poly(d,l-lactic acid) and poly(lactic-co-glycolic acid), the scattering after 7 days of incubation was attributed to water in microvoids that form following the hydrolytic degradation of the polymer. In amorphous copolymers containing hydrophobic segments (desaminotyrosyl-tyrosine ethyl ester) and hydrophilic blocks (poly(ethylene glycol) (PEG)), a sequence of distinct regimes of hydration were observed: homogeneous distribution (∼10Å length scales) at <13 wt.% PEG (∼1 water per EG), clusters of hydrated domains (∼50Å radius) separated at 24 wt.% PEG (1-2 water per EG), uniformly distributed hydrated domains at 41 wt.% PEG (∼4 water per EG) and phase inversion at >50 wt.% PEG (>6 water per EG). Increasing the PEG content increased the number of these domains with only a small decrease in distance between the domains. These discrete domains appeared to coalesce to form submicron droplets at ∼60°C, above the melting temperature of crystalline PEG. The significance of such observations on the evolution of micrometer-size channels that form during hydrolytic erosion is discussed.
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Toledano M, Yamauti M, Osorio E, Monticelli F, Osorio R. Characterization of micro- and nanophase separation of dentin bonding agents by stereoscopy and atomic force microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2012; 18:279-288. [PMID: 22300801 DOI: 10.1017/s1431927611012621] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The aim was to study the effect of solvents on the phase separation of four commercial dental adhesives. Four materials were tested: Clearfil™ SE Bond (CSE), Clearfil Protect Bond (CPB), Clearfil S3 Bond (CS3), and One-Up Bond F Plus (OUB). Distilled water or ethanol was used as a solvent (30 vol%) for microphase separation studies, by stereoscopy. For nanophase images, the mixtures were formulated with two different solvent concentrations (2.5 versus 5 vol%) and observed by atomic force microscopy. Images were analyzed by using MacBiophotonics ImageJ to measure the area of bright domains. Macrophase separations, identified as a loss of clarity, were only observed after mixing the adhesives with water. Nanophase separations were detected with all adhesive combinations. The area of bright domains ranged from 132 to 1,145 nm² for CSE, from 15 to 285 nm² for CPB, from 149 to 380 nm² for CS3, and from 26 to 157 nm² for OUB. In water-resins mixtures, CPB was the most homogeneous and OUB showed the most heterogeneous phase formation. In ethanol-resin mixtures, CSE attained the most homogeneous structure and OUB showed the most heterogeneous phase. Addition of 5 vol% ethanol to resins decreased the nanophase separation when compared with the control materials.
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Affiliation(s)
- Manuel Toledano
- Materiales Dentales, Facultad de Odontología, Colegio Máximo, Campus de Cartuja sn, Universidad de Granada, Granada 18071, Spain.
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Li H, Sun L, Shen G, Liang Q. The nanoscale phase distinguishing of PCL-PB-PCL blended in epoxy resin by tapping mode atomic force microscopy. NANOSCALE RESEARCH LETTERS 2012; 7:153. [PMID: 22360980 PMCID: PMC3311068 DOI: 10.1186/1556-276x-7-153] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Accepted: 02/23/2012] [Indexed: 05/31/2023]
Abstract
In this work, we investigated the bulk phase distinguishing of the poly(ε-caprolactone)-polybutadiene-poly(ε-caprolactone) (PCL-PB-PCL) triblock copolymer blended in epoxy resin by tapping mode atomic force microscopy (TM-AFM). We found that at a set-point amplitude ratio (rsp) less than or equal to 0.85, a clear phase contrast could be obtained using a probe with a force constant of 40 N/m. When rsp was decreased to 0.1 or less, the measured size of the PB-rich domain relatively shrank; however, the height images of the PB-rich domain would take reverse (translating from the original light to dark) at rsp = 0.85. Force-probe measurements were carried out on the phase-separated regions by TM-AFM. According to the phase shift angle vs. rsp curve, it could be concluded that the different force exerting on the epoxy matrix or on the PB-rich domain might result in the height and phase image reversion. Furthermore, the indentation depth vs. rsp plot showed that with large tapping force (lower rsp), the indentation depth for the PB-rich domain was nearly identical for the epoxy resin matrix.
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Affiliation(s)
- Huiqin Li
- Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Limin Sun
- Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Guangxia Shen
- Research Institute of Micro/Nano Science and Technology, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Qi Liang
- Instrumental Analysis Center, Shanghai Jiao Tong University, Shanghai, 200240, China
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Ye Q, Park J, Parthasarathy R, Pamatmat F, Misra A, Laurence JS, Marangos O, Spencer P. Quantitative analysis of aqueous phase composition of model dentin adhesives experiencing phase separation. J Biomed Mater Res B Appl Biomater 2012; 100:1086-92. [PMID: 22331596 DOI: 10.1002/jbm.b.32675] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2011] [Revised: 12/18/2011] [Accepted: 12/22/2011] [Indexed: 11/05/2022]
Abstract
There have been reports of the sensitivity of our current dentin adhesives to excess moisture, for example, water-blisters in adhesives placed on over-wet surfaces, and phase separation with concomitant limited infiltration of the critical dimethacrylate component into the demineralized dentin matrix. To determine quantitatively the hydrophobic/hydrophilic components in the aqueous phase when exposed to over-wet environments, model adhesives were mixed with 16, 33, and 50 wt % water to yield well-separated phases. Based upon high-performance liquid chromatography coupled with photodiode array detection, it was found that the amounts of hydrophobic BisGMA and hydrophobic initiators are less than 0.1 wt % in the aqueous phase. The amount of these compounds decreased with an increase in the initial water content. The major components of the aqueous phase were hydroxyethyl methacrylate (HEMA) and water, and the HEMA content ranged from 18.3 to 14.7 wt %. Different BisGMA homologues and the relative content of these homologues in the aqueous phase have been identified; however, the amount of crosslinkable BisGMA was minimal and, thus, could not help in the formation of a crosslinked polymer network in the aqueous phase. Without the protection afforded by a strong crosslinked network, the poorly photoreactive compounds of this aqueous phase could be leached easily. These results suggest that adhesive formulations should be designed to include hydrophilic multimethacrylate monomers and water compatible initiators.
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Affiliation(s)
- Qiang Ye
- Bioengineering Research Center, University of Kansas, Lawrence, Kansas 66045-7609, USA.
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Qi YP, Li N, Niu LN, Primus CM, Ling JQ, Pashley DH, Tay FR. Remineralization of artificial dentinal caries lesions by biomimetically modified mineral trioxide aggregate. Acta Biomater 2012; 8:836-42. [PMID: 22085925 DOI: 10.1016/j.actbio.2011.10.033] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 09/23/2011] [Accepted: 10/26/2011] [Indexed: 01/20/2023]
Abstract
Fluoride-releasing restorative materials are available for remineralization of enamel and root caries. However, remineralization of dentin is more difficult than remineralization of enamel due to the paucity of apatite seed crystallites along the lesion surface for heterogeneous crystal growth. Extracellular matrix proteins play critical roles in controlling apatite nucleation/growth in collagenous tissues. This study examined the remineralization efficacy of mineral trioxide aggregate (MTA) in phosphate-containing simulated body fluid (SBF) by incorporating polyacrylic acid and sodium tripolyphosphate as biomimetic analogs of matrix proteins for remineralizing caries-like dentin. Artificial caries-like dentin lesions incubated in SBF were remineralized over a 6 week period using MTA alone or MTA containing biomimetic analogs in the absence or presence of dentin adhesive application. Lesion depths and integrated mineral loss were monitored with microcomputed tomography. The ultrastructure of baseline and remineralized lesions was examined by transmission electron microscopy. Dentin remineralization was best achieved using MTA containing biomimetic analogs regardless of whether an adhesive was applied; dentinal tubules within the remineralized dentin were occluded by apatite. It is concluded that the version of MTA employed in this study may be doped with biomimetic analogs for remineralization of unbonded and bonded artificial caries-like lesions in the presence of SBF.
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Spencer P, Jonggu Park QY, Misra A, Bohaty BS, Singh V, Parthasarathy R, Sene F, de Paiva Gonçalves SE, Laurence J. Durable bonds at the adhesive/dentin interface: an impossible mission or simply a moving target? BRAZILIAN DENTAL SCIENCE 2012; 15:4-18. [PMID: 24855586 PMCID: PMC4028112 DOI: 10.14295/bds.2012.v15i1.790] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/24/2023] Open
Abstract
Composite restorations have higher failure rates, more recurrent caries and increased frequency of replacement as compared to dental amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and failure. The gingival margin of composite restora tions is particularly vulnerable to decay and at this margin, the adhesive and its seal to dentin provides the primary barrier between the prepared tooth and the environment. The intent of this article is to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface.
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Affiliation(s)
- Paulette Spencer
- Department of Mechanical Engineering - Bioengineering Research Center - University of Kansas - Lawrence - KS
| | | | - Anil Misra
- Bioengineering Research Center - Department of Civil Engineering - University of Kansas - Lawrence - KS
| | - Brenda S Bohaty
- Department of Pediatric Dentistry - University of Missouri - Kansas City - School of Dentistry - Kansas City - MO
| | - Viraj Singh
- Department of Mechanical Engineering - Bioengineering Research Center - University of Kansas - Lawrence - KS
| | | | - Fábio Sene
- Department of Restorative Dentistry - State University of Londrina - School of Dentistry - Londrina - Brazil
| | - Sérgio Eduardo de Paiva Gonçalves
- Department of Restorative Dentistry - School of Dentistry of São José dos Campos - UNESP - Univ Estadual Paulista - São José dos Campos - SP - Brazil
| | - Jennifer Laurence
- Department of Pharmaceutical Chemistry - University of Kansas - Lawrence - KS
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Osorio E, Toledano M, Yamauti M, Osorio R. Differential nanofiller cluster formations in dental adhesive systems. Microsc Res Tech 2011; 75:749-57. [DOI: 10.1002/jemt.21121] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Accepted: 10/25/2011] [Indexed: 11/12/2022]
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Ye Q, Park J, Laurence JS, Parthasarathy R, Misra A, Spencer P. Ternary phase diagram of model dentin adhesive exposed to over-wet environments. J Dent Res 2011; 90:1434-8. [PMID: 21960682 DOI: 10.1177/0022034511423398] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
When adhesives and/or composites are bonded to the tooth, water in the environment can interfere with proper interface formation. Formation of water blisters and phase separation at the adhesive/dentin interface have appeared as new types of bond defects. To better understand this problem, we determined the near-equilibrium partition of the hydrophobic/hydrophilic components when exposed to over-wet environments. Model methacrylate-based adhesives were mixed with different amounts of water to yield well-separated aqueous and resin phases. It was found that less than 0.1% BisGMA but nearly one-third of the HEMA diffused into the aqueous phase, leaving the remaining resin phase relatively hydrophobic. A partial phase diagram was created for the ternary BisGMA/HEMA/water system. All the experimental phase partitioning data were plotted, and the points lay on a binodal curve that separated the single-phase region from the two-phase region. We obtained the 3 tie lines by connecting the 2 points of each conjugate pair of the phase partitioning data from the 3 sets of tripartite mixtures. Information about solubility, water miscibility, distribution ratio, and phase partitioning behavior could be obtained quantitatively. This type of phase diagram will provide a more thorough understanding of current adhesive performance and elucidate directions for further improvement.
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Affiliation(s)
- Q Ye
- Bioengineering Research Center, University of Kansas, Lawrence, KS 66045-7609, USA.
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Liu Y, Tjäderhane L, Breschi L, Mazzoni A, Li N, Mao J, Pashley DH, Tay FR. Limitations in bonding to dentin and experimental strategies to prevent bond degradation. J Dent Res 2011; 90:953-68. [PMID: 21220360 DOI: 10.1177/0022034510391799] [Citation(s) in RCA: 423] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The limited durability of resin-dentin bonds severely compromises the lifetime of tooth-colored restorations. Bond degradation occurs via hydrolysis of suboptimally polymerized hydrophilic resin components and degradation of water-rich, resin-sparse collagen matrices by matrix metalloproteinases (MMPs) and cysteine cathepsins. This review examined data generated over the past three years on five experimental strategies developed by different research groups for extending the longevity of resin-dentin bonds. They include: (1) increasing the degree of conversion and esterase resistance of hydrophilic adhesives; (2) the use of broad-spectrum inhibitors of collagenolytic enzymes, including novel inhibitor functional groups grafted to methacrylate resins monomers to produce anti-MMP adhesives; (3) the use of cross-linking agents for silencing the activities of MMP and cathepsins that irreversibly alter the 3-D structures of their catalytic/allosteric domains; (4) ethanol wet-bonding with hydrophobic resins to completely replace water from the extrafibrillar and intrafibrillar collagen compartments and immobilize the collagenolytic enzymes; and (5) biomimetic remineralization of the water-filled collagen matrix using analogs of matrix proteins to progressively replace water with intrafibrillar and extrafibrillar apatites to exclude exogenous collagenolytic enzymes and fossilize endogenous collagenolytic enzymes. A combination of several of these strategies should result in overcoming the critical barriers to progress currently encountered in dentin bonding.
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Affiliation(s)
- Y Liu
- Department of Stomatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hankou District, Wuhan 430030, People's Republic of China
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Pashley DH, Tay FR, Breschi L, Tjäderhane L, Carvalho RM, Carrilho M, Tezvergil-Mutluay A. State of the art etch-and-rinse adhesives. Dent Mater 2010; 27:1-16. [PMID: 21112620 DOI: 10.1016/j.dental.2010.10.016] [Citation(s) in RCA: 598] [Impact Index Per Article: 42.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Accepted: 10/22/2010] [Indexed: 11/18/2022]
Abstract
OBJECTIVES The aim of this study was to explore the therapeutic opportunities of each step of 3-step etch-and-rinse adhesives. METHODS Etch-and-rinse adhesive systems are the oldest of the multi-generation evolution of resin bonding systems. In the 3-step version, they involve acid-etching, priming and application of a separate adhesive. Each step can accomplish multiple goals. Acid-etching, using 32-37% phosphoric acid (pH 0.1-0.4) not only simultaneously etches enamel and dentin, but the low pH kills many residual bacteria. RESULTS Some etchants include anti-microbial compounds such as benzalkonium chloride that also inhibits matrix metalloproteinases (MMPs) in dentin. Primers are usually water and HEMA-rich solutions that ensure complete expansion of the collagen fibril meshwork and wet the collagen with hydrophilic monomers. However, water alone can re-expand dried dentin and can also serve as a vehicle for protease inhibitors or protein cross-linking agents that may increase the durability of resin-dentin bonds. In the future, ethanol or other water-free solvents may serve as dehydrating primers that may also contain antibacterial quaternary ammonium methacrylates to inhibit dentin MMPs and increase the durability of resin-dentin bonds. The complete evaporation of solvents is nearly impossible. SIGNIFICANCE Manufacturers may need to optimize solvent concentrations. Solvent-free adhesives can seal resin-dentin interfaces with hydrophobic resins that may also contain fluoride and antimicrobial compounds. Etch-and-rinse adhesives produce higher resin-dentin bonds that are more durable than most 1 and 2-step adhesives. Incorporation of protease inhibitors in etchants and/or cross-linking agents in primers may increase the durability of resin-dentin bonds. The therapeutic potential of etch-and-rinse adhesives has yet to be fully exploited.
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Affiliation(s)
- David H Pashley
- Department of Oral Biology, Medical College of Georgia, School of Dentistry, Augusta, GA, USA.
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Malacarne-Zanon J, de Andrade e Silva SM, Wang L, de Goes MF, Martins AL, Narvaes-Romani EO, Anido-Anido A, Carrilho MRO. Permeability of Dental Adhesives - A SEM Assessment. Eur J Dent 2010; 4:429-39. [PMID: 20922163 PMCID: PMC2948747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVES To morphologically evaluate the permeability of different commercial dental adhesives using scanning electron microscopy. METHODS SEVEN ADHESIVE SYSTEMS WERE EVALUATED: one three-step system (Scotchbond Multi-Purpose - MP); one two-step self-etching primer system (Clearfil SE Bond - SE); three two-step etch-and-rinse systems (Single Bond 2 - SB; Excite - EX; One-Step - OS); and two single-step self-etching adhesives (Adper Prompt - AP; One-Up Bond F - OU). The mixture of primer and bond agents of the Clearfil SE Bond system (SE-PB) was also tested. The adhesives were poured into a brass mold (5.8 mm x 0.8 mm) and light-cured for 80 s at 650 mW/cm2. After a 24 h desiccation process, the specimens were immersed in a 50% ammoniac silver nitrate solution for tracer permeation. Afterwards, they were sectioned in ultra-fine slices, carbon-coated, and analyzed under backscattered electrons in a scanning electron microscopy. RESULTS MP and SE showed slight and superficial tracer permeation. In EX, SB, and OS, permeation extended beyond the inner superficies of the specimens. SE-PB did not mix well, and most of the tracer was precipitated into the primer agent. In AP and OU, "water-trees" were observed all over the specimens. CONCLUSIONS Different materials showed distinct permeability in aqueous solution. The extent of tracer permeation varied according to the composition of each material and it was more evident in the more hydrophilic and solvated ones.
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Affiliation(s)
- Juliana Malacarne-Zanon
- Department of Prosthodontics, School of Dentistry, Federal University of Espírito Santo, Vitória, ES, Brazil
| | | | - Linda Wang
- Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil
| | - Mario F. de Goes
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba School of Dentistry, State University of Campinas, Piracicaba, SP, Brazil
| | - Adriano Luis Martins
- Department of Morphology, Piracicaba School of Dentistry, State University of Campinas, Piracicaba, SP, Brazil
| | - Eliene O. Narvaes-Romani
- Department of Morphology, Piracicaba School of Dentistry, State University of Campinas, Piracicaba, SP, Brazil
| | - Andrea Anido-Anido
- Health Institute of Bandeirante University of São Paulo, GEO/UNIBAN, São Paulo, SP, Brazil
| | - Marcela R. O. Carrilho
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba School of Dentistry, State University of Campinas, Piracicaba, SP, Brazil, Health Institute of Bandeirante University of São Paulo, GEO/UNIBAN, São Paulo, SP, Brazil,Corresponding author: Marcela R. O. Carrilho, Rua Alagoas, 475, 13B, São Paulo, 01242-001, Brazil, Phone: +55 11 83974904 Fax: +55 11 30917840, E-mail:
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Ritts AC, Li H, Yu Q, Xu C, Yao X, Hong L, Wang Y. Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration. Eur J Oral Sci 2010; 118:510-6. [PMID: 20831586 DOI: 10.1111/j.1600-0722.2010.00761.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The objective of this study was to investigate the treatment effects of non-thermal atmospheric gas plasmas on dentin surfaces used for composite restoration. Extracted unerupted human third molars were prepared by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. The dentin surfaces were treated using a non-thermal atmospheric argon plasma brush for various periods of time. The molecular changes of the dentin surfaces were analyzed using Fourier transform infrared spectrophotometry/attenuated total reflectance (FTIR/ATR), and an increase in the amount of carbonyl groups was detected on plasma-treated dentin surfaces. Adper Single Bond Plus adhesive and Filtek Z250 dental composite were applied as directed. To evaluate the dentin/composite interfacial bonding, the teeth thus prepared were sectioned into micro-bars and analyzed using tensile testing. Student-Newman-Keuls tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s of plasma treatment. However, the bonding strength to plasma-treated inner dentin did not show any improvement. It was found that plasma treatment of the peripheral dentin surface for up to 100 s resulted in an increase in the interfacial bonding strength, while prolonged plasma treatment of dentin surfaces (e.g. 5 min) resulted in a decrease in the interfacial bonding strength.
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Affiliation(s)
- Andy C Ritts
- Center for Surface Science and Plasma Technology, Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO 65211, USA
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Water sorption/solubility of self-etching dentin bonding agents. Dent Mater 2010; 26:617-26. [PMID: 20382415 DOI: 10.1016/j.dental.2010.03.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 11/13/2009] [Accepted: 03/05/2010] [Indexed: 11/21/2022]
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Park J, Ye Q, Topp EM, Misra A, Kieweg SL, Spencer P. Effect of photoinitiator system and water content on dynamic mechanical properties of a light-cured bisGMA/HEMA dental resin. J Biomed Mater Res A 2010; 93:1245-51. [PMID: 19827107 PMCID: PMC2860647 DOI: 10.1002/jbm.a.32617] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The selection of an appropriate photoinitiator system is critical for efficient polymerization of dental resins with satisfactory mechanical and physical properties. The purpose of this study was to evaluate the influence of adding an iodonium salt to two-component photoinitiator systems. Four photoinitiator systems were included in a model bisGMA/HEMA resin and used to prepare samples at different water contents; the dynamic mechanical properties and the final degree of conversion of the samples were then characterized. Addition of the iodonium salt to the two-component photoinitiator systems increased the final degree of conversion, glass transition temperature, rubbery modulus, and crosslink density. The photoinitiator system containing ethyl-4-(dimethylamino) benzoate as a coinitiator and the iodonium salt exhibited the highest rubbery modulus. The enhanced properties in the presence of the iodonium salt can be attributed to the production of an active phenyl radical with regeneration of the original camphorquinone, which may increase the compatibility between monomers and initiators, especially in the presence of water. The results support the hypothesis that a photoinitiator system containing an iodonium salt can increase both mechanical properties and final conversion of model resin polymerized in the presence of water.
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Affiliation(s)
- Jonggu Park
- Bioengineering Research Center, University of Kansas, Lawrence, KS, USA
| | - Qiang Ye
- Bioengineering Research Center, University of Kansas, Lawrence, KS, USA
| | - Elizabeth M. Topp
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, USA
| | - Anil Misra
- Bioengineering Research Center, University of Kansas, Lawrence, KS, USA
- Department of Civil, Environmental and Architectural Engineering, University of Kansas, Lawrence, KS, USA
| | - Sarah L. Kieweg
- Department of Mechanical Engineering, University of Kansas, Lawrence, KS, USA
| | - Paulette Spencer
- Bioengineering Research Center, University of Kansas, Lawrence, KS, USA
- Department of Mechanical Engineering, University of Kansas, Lawrence, KS, USA
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Spencer P, Ye Q, Park J, Topp EM, Misra A, Marangos O, Wang Y, Bohaty BS, Singh V, Sene F, Eslick J, Camarda K, Katz JL. Adhesive/Dentin interface: the weak link in the composite restoration. Ann Biomed Eng 2010; 38:1989-2003. [PMID: 20195761 PMCID: PMC2871971 DOI: 10.1007/s10439-010-9969-6] [Citation(s) in RCA: 294] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Accepted: 02/12/2010] [Indexed: 11/30/2022]
Abstract
Results from clinical studies suggest that more than half of the 166 million dental restorations that were placed in the United States in 2005 were replacements for failed restorations. This emphasis on replacement therapy is expected to grow as dentists use composite as opposed to dental amalgam to restore moderate to large posterior lesions. Composite restorations have higher failure rates, more recurrent caries, and increased frequency of replacement as compared to amalgam. Penetration of bacterial enzymes, oral fluids, and bacteria into the crevices between the tooth and composite undermines the restoration and leads to recurrent decay and premature failure. Under in vivo conditions the bond formed at the adhesive/dentin interface can be the first defense against these noxious, damaging substances. The intent of this article is to review structural aspects of the clinical substrate that impact bond formation at the adhesive/dentin interface; to examine physico-chemical factors that affect the integrity and durability of the adhesive/dentin interfacial bond; and to explore how these factors act synergistically with mechanical forces to undermine the composite restoration. The article will examine the various avenues that have been pursued to address these problems and it will explore how alterations in material chemistry could address the detrimental impact of physico-chemical stresses on the bond formed at the adhesive/dentin interface.
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Affiliation(s)
- Paulette Spencer
- Department of Mechanical Engineering, University of Kansas, 1530 W 15th St, Lawrence, KS 66045, USA.
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Hashimoto M, Nagano F, Endo K, Ohno H. Measurements of volatile compound contents in resins using a moisture analyzer. Eur J Oral Sci 2010; 118:94-9. [DOI: 10.1111/j.1600-0722.2009.00699.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Sharrock P, Grégoire G. HEMA reactivity with demineralized dentin. J Dent 2009; 38:331-5. [PMID: 20036305 DOI: 10.1016/j.jdent.2009.12.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2009] [Revised: 12/17/2009] [Accepted: 12/18/2009] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES 2-Hydroxyethylmethacrylate (HEMA) was compared to its epoxy analogue, glycidoxypropylmethacrylate (GMA), for reactivity with 2,6-diaminohexanoic acid (Lysine), an amino acid present in collagen possessing a reactive amino side chain. The aim was to verify whether HEMA could chemically react with collagen fibers. METHODS Capillary electrophoresis was used to analyse reaction products together with computer aided chemistry. Retention of HEMA in demineralized dentine particles was investigated by infrared spectroscopy. RESULTS It was found by that HEMA does not form any new molecular species when contacted with lysine whereas GMA completely reacts to form the expected addition product. Computer aided chemistry confirmed this finding. Infrared spectroscopy showed that demineralized dentin has strong affinity for HEMA and retains this monomer despite extensive water washing. CONCLUSIONS We interpret this behavior as demonstrating solvation of HEMA in the collagen polymer network.
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Affiliation(s)
- Patrick Sharrock
- Medical and Spatial Imaging Laboratory, University Toulouse III, Toulouse, France
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Park JG, Ye Q, Topp EM, Spencer P. Enzyme-catalyzed hydrolysis of dentin adhesives containing a new urethane-based trimethacrylate monomer. J Biomed Mater Res B Appl Biomater 2009; 91:562-571. [PMID: 19582843 PMCID: PMC2758931 DOI: 10.1002/jbm.b.31430] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A new trimethacrylate monomer with urethane-linked groups, 1,1,1-tri-[4-(methacryloxyethylamino-carbonyloxy)-phenyl]ethane (MPE), was synthesized, characterized, and used as a comonomer in dentin adhesives. Dentin adhesives containing 2-hydroxyethyl methacrylate (HEMA, 45% w/w) and 2,2-bis[4(2-hydroxy-3-methacryloyloxy-propyloxy)-phenyl] propane (BisGMA, 30% w/w) in addition to MPE (25% w/w) were formulated with H(2)O at 0 (MPE0), 8 (MPE8), and 16 wt % water (MPE16) to simulate the wet demineralized dentin matrix and compared with controls [HEMA /BisGMA, 45/55 w/w, at 0 (C0), 8 (C8), and 16 wt % water (C16)]. The new adhesive showed a degree of double bond conversion and mechanical properties comparable with control, with good penetration into the dentin surface and a uniform adhesive/dentin interface. On exposure to porcine liver esterase, the net cumulative methacrylic acid (MAA) released from the new adhesives was dramatically (p < 0.05) decreased relative to the control, suggesting that the new monomer improves esterase resistance.
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Affiliation(s)
- Jong-Gu Park
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, 66045
| | - Qiang Ye
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, 66045
| | - Elizabeth M. Topp
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Kansas, Lawrence, KS 66047
| | - Paulette Spencer
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, 66045,Department of Mechanical Engineering, University of Kansas, Lawrence, KS, 66045, Address all correspondence to Dr. Paulette Spencer. Tel.: +1 785 864 8140; fax: 1 785 864 5254;
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Park JG, Ye Q, Topp EM, Misra A, Spencer P. Water sorption and dynamic mechanical properties of dentin adhesives with a urethane-based multifunctional methacrylate monomer. Dent Mater 2009; 25:1569-75. [PMID: 19709724 DOI: 10.1016/j.dental.2009.07.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2009] [Revised: 07/22/2009] [Accepted: 07/24/2009] [Indexed: 11/29/2022]
Abstract
OBJECTIVES Our previous study showed the synthesis and characterization of a novel urethane-linked trimethacrylate monomer for use as a co-monomer in dentin adhesives. The objective of this work was to further investigate the performance of dentin adhesives containing a new monomer, with particular emphasis on the water sorption and viscoelastic behavior of the crosslinked networks. MATERIALS AND METHODS Dentin adhesives contained 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]-propane (BisGMA), 2-hydroxyethyl methacrylate (HEMA), and a new multifunctional methacrylate with urethane-linked groups-1,1,1-tri-[4-(methacryloxyethylaminocarbonyloxy)-phenyl]ethane (MPE) and were photo-polymerized in the presence or absence of water. Adhesives were characterized with regard to degree of conversion (DC), viscosity, water sorption/solubility, and dynamic mechanical analysis (DMA) and compared with BisGMA/HEMA controls. RESULTS The experimental adhesives exhibited DC and solubility comparable to that of the control, regardless of the presence or absence of water. All the experimental adhesives tested showed less water sorption, lower tandelta peak heights, and higher rubbery modulus than the control. SIGNIFICANCE Dentin adhesives containing a new multifunctional methacrylate showed better dynamic thermomechanical properties and water sorption relative to controls, without compromising DC and solubility. Thus, MPE, when included as a component of methacrylate dentin adhesives, may provide enhanced durability in the moist environment of the mouth.
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Affiliation(s)
- Jong-Gu Park
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA
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Shin TP, Yao X, Huenergardt R, Walker MP, Wang Y. Morphological and chemical characterization of bonding hydrophobic adhesive to dentin using ethanol wet bonding technique. Dent Mater 2009; 25:1050-7. [PMID: 19371945 DOI: 10.1016/j.dental.2009.03.006] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 03/02/2009] [Accepted: 03/07/2009] [Indexed: 10/20/2022]
Abstract
OBJECTIVE BisGMA, a widely used component in dentin adhesive has very good mechanical properties after curing, but is relatively hydrophobic and thus, does not adequately infiltrate the water wet demineralized dentin collagen. Developing techniques that would lead to optimum infiltration of the hydrophobic component into the demineralized dentin matrix is very important. The purpose of this study was to evaluate interfacial morphological and chemical characteristics of the resultant adhesive-dentin interface when the ethanol wet bonding technique is used with hydrophobic adhesives. MATERIALS AND METHODS The occlusal one-third of the crown was removed from six unerupted human third molars; a uniform smear layer was created with 600 grit SiC. The dentin surface was etched with 35% phosphoric acid for 15s before applying BisGMA/HEMA model adhesive using either water wet or ethanol wet bonding technique. Five-micro-thick sections of adhesive/dentin interface specimens were cut and stained with Goldner's trichrome for light microscopy. Companion slabs were analyzed with SEM and micro-Raman spectroscopy. RESULTS The presence of ethanol in the demineralized dentin increased adhesive collagen encapsulation as indicated by trichrome staining. The SEM results confirmed that the ethanol wet bonding improved the quality of the interface. Micro-Raman spectral analysis of the dentin/adhesive interface indicated there was a gradual decrease in penetration of BisGMA component for specimens using water wet bonding, while relatively homogeneous distribution of the hydrophobic BisGMA component was noted in the interface with ethanol wet bonding. SIGNIFICANCE Wet bonding with ethanol instead of water permits better BisGMA infiltration improving the quality of interface. We speculate that the higher infiltration of hydrophobic BisGMA and better collagen encapsulation observed from the specimens using ethanol wet bonding would lead to more durable bonds because of improved resistance to hydrolytic attack.
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Affiliation(s)
- T Phillip Shin
- University of Missouri-Kansas City, School of Dentistry, 650 East 25th Street, Kansas City, MO 64108, United States
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Effect of photoinitiators on the in vitro performance of a dentin adhesive exposed to simulated oral environment. Dent Mater 2009. [PMID: 19027937 PMCID: PMC2748304 DOI: 10.1016/j.dental.2008.09.01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
OBJECTIVES Our previous study showed poor mechanical durability and nano-sized heterogeneities in cross-linked dentin adhesives cured in the presence of water. To further explore the relationship between nano-scale heterogeneities and the long-term mechanical properties of dentin adhesives, the properties of model dentin adhesives polymerized using hydrophilic photoinitiators were compared with those of adhesives polymerized using hydrophobic camphorquinone-based photoinitiators. METHODS The model adhesives consisted of HEMA and bisGMA with a mass ratio of 45/55 and were photopolymerized in the presence of 8.3 mass% water. The photo-polymerization of the model adhesives during irradiation was monitored in situ using a Perkin-Elmer Spectrum One FTIR in the ATR sampling mode. The tensile properties were determined for all samples after dry storage at room temperature, or after aqueous storage in distilled deionized water. RESULTS There was a continuous decline of mechanical properties for the specimens cured in the presence of water during 3 months aqueous storage, especially for the specimens that contained hydrophobic photoinitiators. The multi-component systems containing hydrophilic photoinitiators were shown to produce superior model dental adhesives when these materials are cured in the presence of water. SIGNIFICANCE Designing initiator systems to perform in this heterogeneous environment may improve the mechanical performance of dentin adhesives, as the results presented here indicate.
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Ye Q, Park J, Topp E, Spencer P. Effect of photoinitiators on the in vitro performance of a dentin adhesive exposed to simulated oral environment. Dent Mater 2009; 25:452-8. [PMID: 19027937 PMCID: PMC2748304 DOI: 10.1016/j.dental.2008.09.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Revised: 08/20/2008] [Accepted: 09/29/2008] [Indexed: 11/20/2022]
Abstract
OBJECTIVES Our previous study showed poor mechanical durability and nano-sized heterogeneities in cross-linked dentin adhesives cured in the presence of water. To further explore the relationship between nano-scale heterogeneities and the long-term mechanical properties of dentin adhesives, the properties of model dentin adhesives polymerized using hydrophilic photoinitiators were compared with those of adhesives polymerized using hydrophobic camphorquinone-based photoinitiators. METHODS The model adhesives consisted of HEMA and bisGMA with a mass ratio of 45/55 and were photopolymerized in the presence of 8.3 mass% water. The photo-polymerization of the model adhesives during irradiation was monitored in situ using a Perkin-Elmer Spectrum One FTIR in the ATR sampling mode. The tensile properties were determined for all samples after dry storage at room temperature, or after aqueous storage in distilled deionized water. RESULTS There was a continuous decline of mechanical properties for the specimens cured in the presence of water during 3 months aqueous storage, especially for the specimens that contained hydrophobic photoinitiators. The multi-component systems containing hydrophilic photoinitiators were shown to produce superior model dental adhesives when these materials are cured in the presence of water. SIGNIFICANCE Designing initiator systems to perform in this heterogeneous environment may improve the mechanical performance of dentin adhesives, as the results presented here indicate.
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Affiliation(s)
- Qiang Ye
- Bioengineering Research Center, The University of Kansas School of Engineering, Lawrence, KS
- Department of Mechanical Engineering, The University of Kansas, Lawrence, KS
| | - Jonggu Park
- Bioengineering Research Center, The University of Kansas School of Engineering, Lawrence, KS
- Department of Mechanical Engineering, The University of Kansas, Lawrence, KS
| | - Elizabeth Topp
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, KS
| | - Paulette Spencer
- Bioengineering Research Center, The University of Kansas School of Engineering, Lawrence, KS
- Department of Mechanical Engineering, The University of Kansas, Lawrence, KS
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