151
|
Abstract
OBJECTIVES A dental adhesive without small and hydrophilic monomers such as 2-hydroxyethyl methacrylate (HEMA) and triethylene glycol dimethacrylate (TEGDMA) would be beneficial in order to avoid contact allergies. However, these monomers are important to increase infiltration and polymerization of the adhesive. Therefore, the purpose of this study was to evaluate the bonding effectiveness and bond durability of a more hydrophobic and biocompatible adhesive as compared to a conventional three-step etch-and-rinse adhesive. METHODS Sixteen non-carious human third molars were used to determine the micro-tensile bond strength testing (μTBS) and interfacial ultrastructure by transmission electron microscopy (TEM) of the more hydrophobic cmf adhesive system (Saremco) adhesive as compared to the control OptiBond FL (Kerr). RESULTS The more hydrophobic and biocompatible three-step etch-and-rinse adhesive was able to produce a reasonable short-time bonding effectiveness. In the long term, the collagen fibrils in the hybrid layer were not effectively protected and were prone to hydrolytic degradation. As a result, long-term bonding effectiveness of this novel adhesive was very low. CONCLUSIONS Application of a more hydrophobic adhesive without altering the application procedure considerably results in a reduced durability of the created bond CLINICAL RELEVANCE Omitting small and hydrophilic components from the adhesive formulation may impair the durability of your composite restoration.
Collapse
|
152
|
Giannini M, Liberti MS, Arrais CAG, Reis AF, Mettenburg D, Rueggeberg FA. Influence of filler addition, storage medium and evaluation time on biaxial flexure strength and modulus of adhesive systems. Acta Odontol Scand 2012; 70:478-84. [PMID: 22150012 DOI: 10.3109/00016357.2011.639308] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE This study evaluated the effects of filler addition, storage medium and time on biaxial flexural strength and flexural modulus of six adhesive systems. MATERIALS AND METHODS The adhesives were either unfilled resins: Single Bond, Prime&Bond 2.1 and One-Step; or filled resins: Single Bond Plus, Prime&Bond NT and One-Step Plus. Resin discs of each product (0.5 mm thick × 6.0 mm diameter) were prepared using silicon molds (n = 10). The discs were stored dry, in water, mineral oil or ethanol for 1 week or 3 months before biaxial flexural testing. Data were statistically analyzed by 3-way ANOVA and Tukey's post-hoc test (α = 0.05). The specimens were tested in a universal testing machine at 1.27 mm/min until failure occurred. RESULTS In general, the storage in ethanol led to significantly lower flexural strength and flexural modulus values than the other storage conditions for all adhesives in both storage periods. Filler addition increased flexural strength and flexural modulus for Prime&Bond NT, when it was stored dry or in water for 1 week. For Single Bond Plus, the filler addition resulted in higher flexural modulus, when it was stored for 1 week in oil and in ethanol. No significant differences in flexural modulus were observed between One-Step and One-Step Plus in any storage medium. CONCLUSIONS Results suggested that filler addition does not necessarily have to increase the flexural strength and flexural modulus. Ethanol and oil storages tended to yield opposite effects.
Collapse
Affiliation(s)
- Marcelo Giannini
- Department of Restorative Dentistry, Operative Dentistry Division, Piracicaba Dental School, State University of Campinas, Piracicaba, SP, Brazil.
| | | | | | | | | | | |
Collapse
|
153
|
Ahn SJ, Cho EJ, Oh SS, Lim BS. The effects of orthodontic bonding steps on biofilm formation of Streptococcus mutans in the presence of saliva. Acta Odontol Scand 2012; 70:504-10. [PMID: 22181697 DOI: 10.3109/00016357.2011.640277] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To investigate the effects of various orthodontic bonding steps on biofilm formation of Streptococcus mutans in the presence of saliva. MATERIALS AND METHODS Hydroxyapatite (HA) and orthodontic adhesive (AD) disks were prepared to a uniform size. HA disks were etched with 37% phosphoric acid gel in the etched group (HE). In the primed group (HP), Transbond XT primer was applied to the etched HA surface and light-cured. For biofilm formation, Streptococcus mutans was grown on each specimen in a biofilm medium with either glucose or sucrose in the presence of fluid-phase UWS (F-UWS) or surface adsorbed saliva (S-UWS). The adherent bacteria were quantified by enumeration of the total viable counts of bacteria. Biofilms formed on each surface were examined by scanning electron microscopy. RESULTS When glucose was used, both F-UWS and S-UWS suppressed biofilm formation of S. mutans. Compared to HA and HE, biofilm formation was significantly inhibited on HP and AD in the presence of glucose. Biofilm-forming patterns that were inhibited by saliva were restored in a sucrose-containing medium. F-UWS promoted biofilm formation on HA and HE, while S-UWS significantly promoted biofilm formation on HP. S. mutans developed biofilm better on HA and HE than on AD when sucrose was used as the sole carbohydrate source. CONCLUSIONS This study suggests that the biofilm development by S. mutans is significantly influenced by the orthodontic bonding procedure. Biofilm formation of S. mutans was inhibited on AD more than other surfaces, irrespective of the presence of saliva or a carbohydrate source.
Collapse
Affiliation(s)
- Sug-Joon Ahn
- Dental Research Institute, School of Dentistry, Seoul National University, Korea
| | | | | | | |
Collapse
|
154
|
Kumar N, Sangi L. Water sorption, solubility, and resultant change in strength among three resin-based dental composites. ACTA ACUST UNITED AC 2012. [PMID: 23188774 DOI: 10.1111/jicd.12012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine the water sorption, solubility, and resultant change in strength of one microhybrid and two nanofilled resin-based composites (RBCs). METHODS Water sorption, solubility, and three-point bending strength (TPBS) characteristics of a microhybrid RBC Filtek(™) Z250 (Z250; batch 8MA; shade A3) and two nanofilled RBCs, namely Filtek(™) Supreme XT "body" (FSB; batch 8NU; shade A3) and "translucent" shades (FST; batch 6C; shade YT) (3M ESPE Dental Products, St Paul, MN, USA) were investigated following 1 and 13 weeks storage regimes. RESULTS FSB displayed a significant increase in water sorption compared with Z250 and FST (P < 0.001), however, the latter demonstrated no significant difference between them following 1 week and 13 weeks immersion periods (P > 0.001). Following the 13-week immersion period, FSB showed greater water solubility compared with Z250 and FST (P < 0.001). FSB exhibited greater TPBS compared with FST in dry control specimens (P < 0.05), but no significant difference among TPBS of all RBCs was identified following the 1-week immersion period (P = 0.290). The TPBS of FSB decreased significantly compared with Z250 and FST following the 13-week immersion period (P < 0.001). CONCLUSION Since the FSB exhibited greater water sorption, solubility, and resulting strength degradation compared with Z250 and FST, a poor clinical performance may be expected.
Collapse
Affiliation(s)
- Naresh Kumar
- Science of Dental Materials Department, Institute of Dentistry, Liaquat University of Medical and Health Sciences, Jamshoro, Pakistan
| | | |
Collapse
|
155
|
Silami FDJ, Mundim FM, Garcia LDFR, Sinhoreti MAC, Pires-de-Souza FDCP. Color stability of experimental composites containing different photoinitiators. J Dent 2012; 41 Suppl 3:e62-6. [PMID: 23089081 DOI: 10.1016/j.jdent.2012.10.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 09/13/2012] [Accepted: 10/09/2012] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVES To evaluate the color stability (ΔE) of experimental composites containing different photoinitiators when submitted to accelerated artificial ageing (AAA). MATERIAL AND METHODS Thirty test specimens were made in a Teflon matrix (8mm×2mm), using an experimental composite (n=10) with the same monomer composition and particle size, but varying photoinitiator used: Group CQ (0.4% Camphorquinone), Group PPD (0.4% 1-Phenyl-1,2 Propanodione) and Group CQ+PPD (0.2% CQ+0.2% PPD). The samples were light activated (QTH - Ultralux - Dabi Atlante - 40s) and polished before performing the initial color readouts (EasyShade - Vita). Next, they were submitted to AAA for 300h, after which final color readouts were made. RESULTS The results (1-way ANOVA - Tukey - p<0.05) demonstrated that all the groups presented color alteration above the clinically acceptable level (ΔE≥3.3), however, with no statistically significant difference among them (p>0.05). Analysis of Δb demonstrated increase in the values of this coordinate, indicating yellowing in all groups. CONCLUSIONS It was concluded that the type of photoinitiator, which presented a tendency towards yellowing, did not interfere in the color stability of composites submitted to AAA. CLINICAL SIGNIFICANCE Alternative photoinitiators have been extensively studied since Camphorquinone presents a yellowish color, which compromises the aesthetic performance of composites, especially the lighter-shade ones.
Collapse
Affiliation(s)
- Francisca Daniele Jardilino Silami
- Department of Dental Materials and Prosthodontics, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil
| | | | | | | | | |
Collapse
|
156
|
Ionescu A, Wutscher E, Brambilla E, Schneider-Feyrer S, Giessibl FJ, Hahnel S. Influence of surface properties of resin-based composites on in vitroStreptococcus mutansbiofilm development. Eur J Oral Sci 2012; 120:458-65. [DOI: 10.1111/j.1600-0722.2012.00983.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2012] [Indexed: 11/30/2022]
Affiliation(s)
- Andrei Ionescu
- Department of Medicine, Surgery and Dentistry; S. Paolo Hospital; University of Milan; Milan; Italy
| | - Elisabeth Wutscher
- Institute of Experimental and Applied Physics; University of Regensburg; Regensburg; Germany
| | - Eugenio Brambilla
- Department of Medicine, Surgery and Dentistry; S. Paolo Hospital; University of Milan; Milan; Italy
| | | | - Franz J. Giessibl
- Institute of Experimental and Applied Physics; University of Regensburg; Regensburg; Germany
| | - Sebastian Hahnel
- Department of Prosthetic Dentistry; University Medical Center Regensburg; Regensburg; Germany
| |
Collapse
|
157
|
Brackett MG, Lewis JB, Kious AR, Messer RLW, Lockwood PE, Brackett WW, Wataha JC. Cytotoxicity of endodontic sealers after one year of agingin vitro. J Biomed Mater Res B Appl Biomater 2012; 100:1729-35. [DOI: 10.1002/jbm.b.32739] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 04/19/2012] [Accepted: 04/24/2012] [Indexed: 11/07/2022]
|
158
|
Andreani L, Silva LL, Witt MA, Meier MM, Joussef AC, Soldi V. Development of dental resinous systems composed of bisphenol a ethoxylated dimethacrylate and three novel methacrylate monomers: Synthesis and characterization. J Appl Polym Sci 2012. [DOI: 10.1002/app.38252] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
159
|
El-Deeb HA, Al Sherbiney HH, Mobarak EH. Bond durability of adhesives containing modified-monomer with/without-fluoride after aging in artificial saliva and under intrapulpal pressure simulation. Oper Dent 2012; 38:48-56. [PMID: 22770483 DOI: 10.2341/11-389-l] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To evaluate the dentin bond strength durability of adhesives containing modified-monomer with/without-fluoride after storage in artificial saliva and under intrapulpal pressure simulation (IPPS). MATERIALS AND METHODS The occlusal enamel of 48 freshly extracted teeth was trimmed to expose midcoronal dentin. Roots were sectioned to expose the pulp chamber and to connect the specimens to the pulpal-pressure assembly. Specimens were assigned into four groups (n=12) according to adhesive system utilized: a two-step etch-and-rinse adhesive system (SB, Adper Single Bond 2, 3M ESPE), a two-step self-etch adhesive system (CSE, Clearfil SE Bond, Kuraray Medical Inc), and two single-step self-etch adhesives with the same modified monomer (bis-acrylamide)-one with fluoride (AOF, AdheSE One F, Ivoclar-Vivadent) and the other without (AO, AdheSE One, Ivoclar-Vivadent). Bonding was carried out while the specimens were subjected to 15-mm Hg IPPS. Resin composite (Valux Plus, 3M ESPE) buildups were made. After curing, specimens were aged in artificial saliva and under 20-mm Hg IPPS at 37°C in a specially constructed incubator either for 24 hours or six months prior to testing. Bonded specimens (n=6/group) were sectioned into sticks (n=24/group) with a cross section of 0.9 ± 0.01 mm(2) and subjected to microtensile bond strength (μTBS) testing using a universal testing machine. Data were statistically analyzed using two-way analysis of variance (ANOVA) with repeated measures, one-way ANOVA tests, and a t-test (p<0.05). Failure modes were determined using a scanning electron microscope. RESULTS The μTBS values of SB and CSE fell significantly after six-month storage in artificial saliva and under IPPS, yet these values remained significantly higher than those for the other two adhesives with modified monomers. There was no significant difference in the bond strength values between fluoride-containing and fluoride-free self-etch adhesive systems (AOF and AO) after 24 hours or six months. Modes of failure were mainly adhesive and mixed. CONCLUSIONS Based on the results of this study, 1) Fluoride addition did not affect dentin bond durability; and 2) despite the fact that the single-step adhesive system with modified monomer showed stability, bond strengths associated with these systems remained lower than those of multistep adhesive systems.
Collapse
Affiliation(s)
- H A El-Deeb
- Restorative Dentistry Department, Faculty of Oral and Dental Medicine, Cairo University, Egypt
| | | | | |
Collapse
|
160
|
Bertassoni LE, Orgel JPR, Antipova O, Swain MV. The dentin organic matrix - limitations of restorative dentistry hidden on the nanometer scale. Acta Biomater 2012; 8:2419-33. [PMID: 22414619 PMCID: PMC3473357 DOI: 10.1016/j.actbio.2012.02.022] [Citation(s) in RCA: 127] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 02/16/2012] [Accepted: 02/28/2012] [Indexed: 11/28/2022]
Abstract
The prevention and treatment of dental caries are major challenges occurring in dentistry. The foundations for modern management of this dental disease, estimated to affect 90% of adults in Western countries, rest upon the dependence of ultrafine interactions between synthetic polymeric biomaterials and nanostructured supramolecular assemblies that compose the tooth organic substrate. Research has shown, however, that this interaction imposes less than desirable long-term prospects for current resin-based dental restorations. Here we review progress in the identification of the nanostructural organization of the organic matrix of dentin, the largest component of the tooth structure, and highlight aspects relevant to understating the interaction of restorative biomaterials with the dentin substrate. We offer novel insights into the influence of the hierarchically assembled supramolecular structure of dentin collagen fibrils and their structural dependence on water molecules. Secondly, we review recent evidence for the participation of proteoglycans in composing the dentin organic network. Finally, we discuss the relation of these complexly assembled nanostructures with the protease degradative processes driving the low durability of current resin-based dental restorations. We argue in favour of the structural limitations that these complexly organized and inherently hydrated organic structures may impose on the clinical prospects of current hydrophobic and hydrolyzable dental polymers that establish ultrafine contact with the tooth substrate.
Collapse
Affiliation(s)
- Luiz E Bertassoni
- Biomaterials Science Research Unit, Faculty of Dentistry, University of Sydney, United Dental Hospital, NSW, Australia.
| | | | | | | |
Collapse
|
161
|
The effects of environment and cyclic fatigue on the mechanical properties of an indirect composite. J Dent 2012; 40:787-92. [PMID: 22722058 DOI: 10.1016/j.jdent.2012.05.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 04/27/2012] [Accepted: 05/25/2012] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVES The purpose of this study was to examine the flexure strength (σ) and fracture toughness (K(IC)) of three indirect dental composites (dentin, body, and incisal) with respect to loading (static and cyclic), testing environments (air and water) and ageing (0 (controls) and 6 months in air and water). METHODS The specimens were 3 mm × 3 mm × 25 mm bars with the fracture toughness specimens having a 0.75 mm notch machined in the midspan. Static testing utilized 15 bars and cyclic testing 25 bars for each testing variable. All bars were tested using three-point loading and the cyclic testing was for 1000 cycles using a staircase approach. RESULTS For flexure strength and fracture toughness, all specimen groups showed a decrease in mean values when exposed to cyclic loading as compared to the static loading mean and when exposed to ageing compared to the control specimens. ANOVA analysis demonstrated that dentin specimens had higher flexure strength and fracture toughness means than incisal and body specimens and that control and water specimens had higher flexure strength and fracture toughness means than aged and air specimens. CONCLUSIONS Degradation of these materials, as a result of cyclic loading and ageing in an aqueous environment, appears to be influenced by more than just the processing of the composite.
Collapse
|
162
|
Park J, Ye Q, Spencer P, Laurence JS. Determination of neutralization capacity and stability of a basic methacrylate monomer using NMR. INT J POLYM MATER PO 2012; 61:144-153. [PMID: 22544985 DOI: 10.1080/00914037.2011.574660] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
The durability of dental resin depends on the stability of the polymer. The neutralizing capacity of a basic methacrylate monomer and its chemical stability were measured using nuclear magnetic resonance (NMR) spectroscopy. Lactic acid solution was titrated with 2-(dimethylamino)ethylmethacrylate (DMAEMA) or 2-hydroxyethylmethacrylate (HEMA) and its chemical shifts monitored. Addition of DMAEMA alters the chemical shift proportionally to pH neutralization, whereas HEMA has no impact. Chemical shifts were used to quantify both the change in pH and monomer stability. The results demonstrate that neutralization by basic monomer can be achieved and that this can be measured using an NMR assay.
Collapse
Affiliation(s)
- Jonggu Park
- Bioengineering Research Center, University of Kansas, Lawrence, KS, USA
| | | | | | | |
Collapse
|
163
|
Michelsen VB, Kopperud HBM, Lygre GB, Björkman L, Jensen E, Kleven IS, Svahn J, Lygre H. Detection and quantification of monomers in unstimulated whole saliva after treatment with resin-based composite fillings in vivo. Eur J Oral Sci 2012; 120:89-95. [PMID: 22288926 DOI: 10.1111/j.1600-0722.2011.00897.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Resin-based dental restorative materials contain allergenic methacrylate monomers, which may be released into saliva after restorative treatment. Monomers from resin-based composite materials have been demonstrated in saliva in vitro; however, studies analyzing saliva after restorative therapy are scarce. The aim of this study was to quantify methacrylate monomers in saliva after treatment with a resin-based composite filling material. Saliva was collected from 10 patients at four start points--before treatment, and 10 min, 24 h, and 7 d after treatment--and analysed by combined chromatography/mass spectrometry. The monomers bisphenol-A diglycidyl methacrylate (Bis-GMA), 2-hydroxyethyl methacrylate (HEMA), and urethane dimethacrylate (UDMA) were detected and quantified in the samples collected shortly (10 min) after treatment. The amounts detected ranged from 0.028 to 9.65 μg ml(-1) for Bis-GMA, from 0.015 to 0.19 μg ml(-1) for HEMA, and from 0.004 to 1.2 μg ml(-1) for UDMA. Triethyleneglycol dimethacrylate (TEGDMA) was detected in four of the samples. Ethoxylated bisphenol-A dimethacrylate (Bis-EMA) was not detected. Monomers were not detected in saliva samples collected before treatment, or 24 h or 7 d after treatment, with the exception of one sample, 24 h after treatment, in which HEMA was detected. In conclusion, monomers from the investigated resin-based composite and adhesive system were present in saliva shortly after treatment. One week after treatment, no monomers could be detected in patients' saliva samples.
Collapse
|
164
|
LEE DS, JEONG TS, KIM S, KIM HI, KWON YH. Effect of dual-peak LED unit on the polymerization of coinitiator-containing composite resins. Dent Mater J 2012; 31:656-61. [DOI: 10.4012/dmj.2012-009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
165
|
Ausiello P, Cassese A, Miele C, Beguinot F, Garcia-Godoy F, Di Jeso B, Ulianich L. Cytotoxicity of dental resin composites: anin vitroevaluation. J Appl Toxicol 2011; 33:451-7. [DOI: 10.1002/jat.1765] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 09/27/2011] [Accepted: 10/01/2011] [Indexed: 11/12/2022]
Affiliation(s)
- Pietro Ausiello
- School of Dentistry; University of Naples ‘Federico II’; Naples; Italy
| | - Angela Cassese
- Department of Molecular and Cellular Biology and Institute of Experimental Endocrinology and Oncology of CNR; University of Naples ‘Federico II’; Naples; Italy
| | - Claudia Miele
- Department of Molecular and Cellular Biology and Institute of Experimental Endocrinology and Oncology of CNR; University of Naples ‘Federico II’; Naples; Italy
| | - Francesco Beguinot
- Department of Molecular and Cellular Biology and Institute of Experimental Endocrinology and Oncology of CNR; University of Naples ‘Federico II’; Naples; Italy
| | - Franklin Garcia-Godoy
- Bioscience Research Center College of Dentistry; University of Tennessee Health Sciences Center; Memphis; TN; USA
| | - Bruno Di Jeso
- Department of Biological and Environmental Sciences and Technologies; University of Lecce; Italy
| | - Luca Ulianich
- Department of Molecular and Cellular Biology and Institute of Experimental Endocrinology and Oncology of CNR; University of Naples ‘Federico II’; Naples; Italy
| |
Collapse
|
166
|
Park J, Ye Q, Singh V, Kieweg SL, Misra A, Spencer P. Synthesis and evaluation of novel dental monomer with branched aromatic carboxylic acid group. J Biomed Mater Res B Appl Biomater 2011; 100:569-76. [PMID: 22114017 DOI: 10.1002/jbm.b.31987] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 09/01/2011] [Accepted: 09/20/2011] [Indexed: 11/06/2022]
Abstract
A new glycerol-based dimethacrylate monomer with an aromatic carboxylic acid, 2-((1,3-bis(methacryloyloxy)propan-2-yloxy)carbonyl)benzoic acid (BMPB), was synthesized, characterized, and proposed as a possible dental co-monomer for dentin adhesives. Dentin adhesives containing 2-hydroxyethyl methacrylate (HEMA) and 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]propane (BisGMA) in addition to BMPB were formulated with water at 0, 5, 10, and 15 wt % to simulate wet, oral conditions, and photo-polymerized. Adhesives were characterized with regard to viscosity, real-time photopolymerization behavior, dynamic mechanical analysis, and microscale 3D internal morphologies and compared with HEMA/BisGMA controls. When formulated under wet conditions, the experimental adhesives showed lower viscosities (0.04-0.07 Pa s) as compared to the control (0.09-0.12 Pa s). The experimental adhesives showed higher glass transition temperature (146-157°C), degree of conversion (78-89%), and rubbery moduli (33-36 MPa), and improved water miscibility (no voids) as compared to the controls (123-135°C, 67-71%, 15-26 MPa, and voids, respectively). The enhanced properties of these adhesives suggest that BMPB with simple, straightforward synthesis is a promising photocurable co-monomer for dental restorative materials.
Collapse
Affiliation(s)
- Jonggu Park
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, Kansas
| | | | | | | | | | | |
Collapse
|
167
|
Szczepanska J, Pawlowska E, Synowiec E, Czarny P, Rekas M, Blasiak J, Szaflik JP. Protective effect of chitosan oligosaccharide lactate against DNA double-strand breaks induced by a model methacrylate dental adhesive. Med Sci Monit 2011; 17:BR201-208. [PMID: 21804456 PMCID: PMC3539618 DOI: 10.12659/msm.881898] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Background Monomers of methacrylates used in restorative dentistry have been recently reported to induce DNA double-strand breaks (DSBs) in human gingival fibroblasts (HGFs) in vitro. Because such monomers may penetrate the pulp and oral cavity due to the incompleteness of polymerization and polymer degradation, they may induce a similar effect in vivo. DSBs are the most serious type of DNA damage and if misrepaired or not repaired may lead to mutation, cancer transformation and cell death. Therefore, the protection against DSBs induced by methacrylate monomers released from dental restorations is imperative. Material/Methods We examined the protective action of chitosan oligosaccharide lactate (ChOL) against cytotoxic and genotoxic effects induced by monomers of the model adhesive consisting of 55% bisphenol A-diglycidyl dimethacrylate (Bis-GMA) and 45% 2-hydroxyethyl methacrylate (HEMA). We evaluated the extent of DSBs by the neutral comet assay and the phosphorylation of the H2AX histone test. Results ChOL increased the viability of HGFs exposed to Bis-GMA/HEMA as assessed by flow cytometry. ChOL decreased the extent of DSBs induced by Bis-GMA/HEMA as evaluated by neutral comet assay and phosphorylation of the H2AX histone. ChOL did not change mechanical properties of the model adhesive, as checked by the shear bond test. Scanning electron microscopy revealed a better sealing of the dentinal microtubules in the presence of ChOL, which may protect pulp cells against the harmful action of the monomers. Conclusions ChOL can be considered as an additive to methacrylate-based dental materials to prevent DSBs induction, but further studies are needed on its formulation with the methacrylates.
Collapse
Affiliation(s)
- Joanna Szczepanska
- Department of Developmental Dentistry, Medical University of Lodz, Lodz, Poland
| | | | | | | | | | | | | |
Collapse
|
168
|
The impact of three strains of oral bacteria on the surface and mechanical properties of a dental resin material. Clin Oral Investig 2011; 16:1095-103. [DOI: 10.1007/s00784-011-0613-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 08/23/2011] [Indexed: 10/17/2022]
|
169
|
Zhang Y, Burrow MF, Palamara JEA, Thomas CDL. Bonding to glass ionomer cements using resin-based adhesives. Oper Dent 2011; 36:618-25. [PMID: 21864124 DOI: 10.2341/10-140-l] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE This study compared the microshear bond strengths (MSBS) of four self-etching adhesives (Adper Scotchbond SE [SSE], Clearfil SE Bond [CSE], Clearfil S3 Bond [CS3] and One Coat 7.0 [OC]) and an etch-and-rinse adhesive (Adper Single Bond Plus [SB]) when bonded to two conventional glass ionomer cements (GICs) (Fuji IX GP EXTRA and Riva Self Cure). The null hypothesis tested was there is no difference in the adhesive ability of an etch-and-rinse adhesive and self-etching adhesives when bonded to GIC for up to 6 months. METHODS The GICs were embedded in type III dental stone and wet ground with 1200-grit SiC paper. Twenty specimens were bonded for each adhesive according to manufacturers' instructions with a 1.5-mm bonding diameter. Specimens were stored at 100% humidity for 24 hours, 1 month, or 6 months. Microshear bond strengths were obtained using a crosshead speed of 1 mm/min. The results were calculated and analyzed using analysis of variance (ANOVA) and Tukey HSD test. RESULTS SB had significantly lower MSBS than the four self-etching adhesives for all storage periods. MSBS at 6 months for SB was significantly lower than at 1 month. There were no significant differences in MSBS among the self-etching adhesives. Cohesive failure within GIC was the most common failure mode observed. CONCLUSIONS SB showed a lower bond strength than the self-etching adhesives when bonded to conventional GICs for all storage periods. This might be a result of the phosphoric acid etching. However, cohesive strength of GIC was a limiting factor for the MSBS outcomes.
Collapse
Affiliation(s)
- Y Zhang
- The University of Melbourne, Melbourne, Victoria, Australia
| | | | | | | |
Collapse
|
170
|
The influence of chemical structure on the properties in methacrylate-based dentin adhesives. Dent Mater 2011; 27:1086-93. [PMID: 21816460 DOI: 10.1016/j.dental.2011.07.011] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 05/18/2011] [Accepted: 07/13/2011] [Indexed: 11/20/2022]
Abstract
OBJECTIVES The objective of this study was to investigate the influence of the chemical structure of methacrylate monomers used in dentin adhesives on degree of conversion (DC), water sorption, and dynamic mechanical properties. MATERIALS AND METHODS Experimental adhesives containing 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]-propane (BisGMA), 2-hydroxyethyl methacrylate (HEMA), and co-monomer, 30/45/25 (w/w) were photo-polymerized. Ethyleneglycol dimethacrylate (EGDM), diethyleneglycol dimethacrylate (DEGDM), triethyleneglycol dimethacrylate (TEGDMA), 1,3-glycerol dimethacrylate (GDM), and glycerol trimethacrylate (GTM) were used as a co-monomer. The adhesives were characterized with regard to DC, water sorption, and dynamic mechanical analysis and compared to control adhesive [HEMA/BisGMA, 45/55 (w/w)]. RESULTS DC and water sorption increased with an increase in the number of ethylene glycol units in the monomer. Experimental adhesive containing GDM showed significantly higher storage moduli (p<0.05) in both dry and wet samples than experimental adhesives containing EGDM or DEGDM. The rubbery moduli of adhesives containing GDM and GTM were found to be significantly greater (p<0.05) than that of the control. Adhesives containing GTM exhibited the widest tanδ curves, indicating the greatest structural heterogeneity. SIGNIFICANCE The hydrophilicity, functionality and size of monomers in dentin adhesives affected the water sorption, solubility, crosslink density and heterogeneity of the polymer network. The experimental adhesives containing GDM and GTM showed higher rubbery moduli, indicating higher crosslink density accompanied by a decrease in the homogeneity of the polymer network structure.
Collapse
|
171
|
D'Antò V, Spagnuolo G, Schweikl H, Rengo S, Ambrosio L, Martina R, Valletta R. Effect of N-acetyl cysteine on orthodontic primers cytotoxicity. Dent Mater 2011; 27:180-6. [PMID: 21081246 DOI: 10.1016/j.dental.2010.10.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 05/05/2010] [Accepted: 10/15/2010] [Indexed: 01/17/2023]
Abstract
OBJECTIVES The aims of this study were to evaluate the cytotoxicity of four orthodontic primers, including two hydrophilic and two hydrophobic materials, and to investigate the role of the reactive oxygen species (ROS) in induced cell damage. Moreover, the effects of the anti-oxidant N-acetyl cysteine (NAC) on primers toxicity was analyzed. METHODS Human gingival fibroblasts (HGF) were exposed to different concentrations of primers (0-0.25 mg/ml) in the presence or absence of NAC, and the cytotoxicity was assessed by the MTT assay, while cell death was quantified by flow cytometry after propidium iodide staining. The increase in the induced ROS levels was detected by flow cytometry measuring the fluorescence of the oxidation-sensitive dye 2',7'-dichlorofluorescein diacetate (DCFH-DA). RESULTS All materials decreased cell viability in a dose-related manner after a 24 h exposure period. Cytotoxicity of orthodontic primers based on concentrations which caused a 50% decrease in cell viability (TC₅₀) in HGF was ranked as follows (median values): Eagle Fluorsure (0.078 mg/ml)>Transbond XT (0.081 mg/ml)>Transbond MIP (0.128 mg/ml)>Ortho solo (0.130 mg/ml). Moreover, in HGF cells, all materials induced a dose-dependent increase in ROS levels compared to untreated cells. Incubation of HGF with NAC significantly reduced ROS production and decreased the cell damage and cytotoxicity caused by all materials tested (p<0.001). SIGNIFICANCE Our results suggested that hydrophilic primers were less cytotoxic than hydrophobic materials. Moreover, we demonstrated a major role of ROS in the induction of cell death since the antioxidant N-acetyl cysteine was able to prevent cell damage induced by all materials tested.
Collapse
Affiliation(s)
- Vincenzo D'Antò
- Department of Oral and Maxillofacial Sciences, University of Naples Federico II, via S. Pansini 5, 80128 Napoli, Italy.
| | | | | | | | | | | | | |
Collapse
|
172
|
Szczepanska J, Poplawski T, Synowiec E, Pawlowska E, Chojnacki CJ, Chojnacki J, Blasiak J. 2-hydroxylethyl methacrylate (HEMA), a tooth restoration component, exerts its genotoxic effects in human gingival fibroblasts trough methacrylic acid, an immediate product of its degradation. Mol Biol Rep 2011; 39:1561-74. [PMID: 21617943 PMCID: PMC3249584 DOI: 10.1007/s11033-011-0895-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 05/17/2011] [Indexed: 12/21/2022]
Abstract
HEMA (2-hydroxyethyl methacrylate), a methacrylate commonly used in dentistry, was reported to induce genotoxic effects, but their mechanism is not fully understood. HEMA may be degraded by the oral cavity esterases or through mechanical stress following the chewing process. Methacrylic acid (MAA) is the primary product of HEMA degradation. In the present work we compared cytotoxic and genotoxic effects induced by HEMA and MAA in human gingival fibroblasts (HGFs). A 6-h exposure to HEMA or MAA induced a weak decrease in the viability of HGFs. Neither HEMA nor MAA induced strand breaks in the isolated plasmid DNA, but both compounds evoked DNA damage in HGFs, as evaluated by the alkaline comet assay. Oxidative modifications to the DNA bases were monitored by the DNA repair enzymes Endo III and Fpg. DNA damage induced by HEMA and MAA was not persistent and was removed during a 120 min repair incubation. Results from the neutral comet assay indicated that both compounds induced DNA double strand breaks (DSBs) and they were confirmed by the γ-H2AX assay. Both compounds induced apoptosis and perturbed the cell cycle. Therefore, methacrylic acid, a product of HEMA degradation, may be involved in its cytotoxic and genotoxic action.
Collapse
Affiliation(s)
- Joanna Szczepanska
- Department of Developmental Dentistry, Medical University of Lodz, Pomorska 251, 92-216 Lodz, Poland
| | - Tomasz Poplawski
- Department of Molecular Genetics, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| | - Ewelina Synowiec
- Department of Molecular Genetics, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| | - Elzbieta Pawlowska
- Department of Developmental Dentistry, Medical University of Lodz, Pomorska 251, 92-216 Lodz, Poland
| | - Cezary J. Chojnacki
- Department of Gastroenterology and Internal Medicine, Medical University of Lodz, Plac Hallera 1, 91-647 Lodz, Poland
| | - Jan Chojnacki
- Department of Gastroenterology and Internal Medicine, Medical University of Lodz, Plac Hallera 1, 91-647 Lodz, Poland
| | - Janusz Blasiak
- Department of Molecular Genetics, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
| |
Collapse
|
173
|
Liu F, Liao L, He J, Luo Y, Jia D. Evaluation of new tri-methacrylates as a reactive diluent in root canal sealant. JOURNAL OF BIOMATERIALS SCIENCE. POLYMER EDITION 2011; 22:1379-1391. [PMID: 20594412 DOI: 10.1163/092050610x508428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
In this work, a novel tri-methacrylate oligomer, GPTEMA, with three long-branched chain structures was synthesized through the reaction of glycerol propoxylate triglycidyl ether (GPTE) and methacrylic acid. The structure of GPTEMA was confirmed by FT-IR, (1)H-NMR, gel-permeation chromatography (GPC) and element analysis. The GPTEMA was used to partially or completely replace TEGDMA as reactive diluent and applied in a root canal sealant system containing Bis-GMA. The effects of GPTEMA on the polymerization behavior of Bis-GMA/TEGDMA/GPTEMA co-polymer and properties of its polymerizing product were investigated. Polymerization shrinkage, double bond conversion, glass transition temperature, flexural strength, flexural modulus, water sorption and diffusion coefficient of the Bis-GMA/TEGDMA/GPTEMA co-polymer were measured. The results illustrated that the Bis-GMA/TEGDMA/GPTEMA co-polymer attained lower polymerization shrinkage and higher double bond conversion. However, its T g, flexural strength and flexural modulus decreased with increasing content of GPTEMA, water sorption and diffusion coefficient increased with increasing content of GPTEMA.
Collapse
Affiliation(s)
- Fang Liu
- a College of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, P.R. China.
| | | | | | | | | |
Collapse
|
174
|
Monomer elution from nanohybrid and ormocer-based composites cured with different light sources. Dent Mater 2010; 27:371-8. [PMID: 21168907 DOI: 10.1016/j.dental.2010.11.017] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 07/27/2010] [Accepted: 11/23/2010] [Indexed: 11/21/2022]
Abstract
OBJECTIVES To study monomer elution from four resin-based composites (RBCs) cured with different light sources. METHODS Twenty-eight premolars were randomly allocated to four groups. Standardized cavities were prepared and restored with a nanohybrid (Filtek Supreme XT or Tetric EvoCeram), an ormocer (Admira) or a microhybrid RBC (Filtek Z250) which served as control. Buccal restorations were cured with a halogen and oral restorations with an LED light-curing unit. Elution of diurethane dimethacrylate (UDMA), Bisphenol A diglycidylether methacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA) and 2-hydroxyethyl methacrylate (HEMA) was analyzed using high-performance liquid chromatography (HPLC) 1h to 28 days post-immersion in 75% ethanol. Data were analyzed using multivariate and repeated measures analysis of variance (α = 0.05). RESULTS The greatest elution of UDMA and BisGMA occurred from Tetric EvoCeram and the least from Filtek Z250 (p < 0.05). LED and halogen light-curing units gave similar results for all RBCs (p > 0.05) except Tetric EvoCeram which showed greater elution for the LED unit (p < 0.05). TEGDMA was below the limit of quantification. HEMA eluted in similar concentrations from Filtek Supreme and Tetric EvoCeram (p > 0.05). SIGNIFICANCE The two nanohybrid RBCs eluted more cross-linking monomers than the ormocer and the control microhybrid RBC. Continuous elution over 28 days indicates that RBCs act as a chronic source of monomers in clinical conditions. Light source may affect monomer elution since differences were found for one out of four RBCs. Mathematical models for elution kinetics of UDMA and BisGMA indicated two elution mechanisms.
Collapse
|
175
|
Krifka S, Petzel C, Bolay C, Hiller KA, Spagnuolo G, Schmalz G, Schweikl H. Activation of stress-regulated transcription factors by triethylene glycol dimethacrylate monomer. Biomaterials 2010; 32:1787-95. [PMID: 21145583 DOI: 10.1016/j.biomaterials.2010.11.031] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Accepted: 11/14/2010] [Indexed: 12/13/2022]
Abstract
Triethylene glycol dimethacrylate (TEGDMA) is a resin monomer available for short exposure scenarios of oral tissues due to incomplete polymerization processes of dental composite materials. The generation of reactive oxygen species (ROS) in the presence of resin monomers is discussed as a common mechanism underlying cellular reactions as diverse as disturbed responses of the innate immune system, inhibition of dentin mineralization processes, genotoxicity and a delayed cell cycle. Yet, the signaling pathway through a network of proteins that finally initiates the execution of monomer-induced specific cell responses is unknown so far. The aim of the present study was to extend the knowledge of molecular mechanisms of monomer-induced cell death as a basis for reasonable therapy strategies. Thus, the monomer-induced expression and phosphorylation of stress-related transcription factors was analyzed in various cell lines. The time-related induction of apoptosis was investigated as well. The expression of p53 increased in HeLa cell cultures treated with camptothecin (positive control) for 24h, and the formation of p53Ser15 and p53Ser46 was detected in cell nuclei by Western blotting. TEGDMA (3 mm) appeared to stimulate p53 expression only slightly, but increased p21 expression was found in cell nuclei and cytoplasm. Both camptothecin and TEGDMA increased p53 expression to some extent in the nuclear fraction in human transformed pulp-derived cells (tHPC), and similar effects were detected in RAW264.7 macrophages. No clear induction of c-Jun and phospho-c-Jun by TEGDMA was detected in HeLa cell nuclei, and the expression of ATF-2 and phospho-ATF-2 was inhibited in the presence of the monomer. ATF-3 expression was found only in the nuclear fraction of camptothecin-treated HeLa cultures. TEGDMA seemed to inhibit the formation of phospho-c-Jun and phospho-ATF-2 in tHPC, and the monomer acted negatively on the expression of c-Jun, ATF-2 and ATF-3 in RAW264.7 macrophages. These changes in the expression and activation of stress-related transcription factors were time-related to the induction of apoptosis by TEGDMA in all cell lines. The present study provides experimental evidence that TEGDMA interferes with the regulation of cellular pathways through transcription factors activated as a consequence of DNA damage like p53 or initiated downstream of MAPK (mitogen-activated protein kinases) like c-Jun, ATF-2 and ATF-3. The direct causal correlation between DNA damage, activation or inhibition of MAPKs and transcription factors, and apoptosis is under current investigation. However, the induction of apoptosis in different cell lines in the presence of monomers like TEGDMA may be subject to a higher level of complexity than currently suggested by simple linear models.
Collapse
Affiliation(s)
- Stephanie Krifka
- Department of Operative Dentistry and Periodontology, University of Regensburg, D-93042 Regensburg, Germany
| | | | | | | | | | | | | |
Collapse
|
176
|
Kachi H, Noda M, Wataha JC, Nakaoki Y, Sano H. Colloidal platinum nanoparticles increase mitochondrial stress induced by resin composite components. J Biomed Mater Res B Appl Biomater 2010; 96:193-8. [DOI: 10.1002/jbm.b.31750] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 08/10/2010] [Accepted: 09/12/2010] [Indexed: 11/06/2022]
|
177
|
Samuelsen JT, Kopperud HM, Holme JA, Dragland IS, Christensen T, Dahl JE. Role of thiol-complex formation in 2-hydroxyethyl- methacrylate-induced toxicity in vitro. J Biomed Mater Res A 2010; 96:395-401. [DOI: 10.1002/jbm.a.32993] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 09/23/2010] [Accepted: 10/12/2010] [Indexed: 01/25/2023]
|
178
|
Rahiotis C. Degree of Cure and Monomer Leaching from Orthodontic Adhesive Resins: In Vitro and in Vivo Evidence. Semin Orthod 2010. [DOI: 10.1053/j.sodo.2010.06.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
179
|
Effects of staining solutions on the discoloration of orthodontic adhesives: An in-vitro study. Am J Orthod Dentofacial Orthop 2010; 138:741-6. [PMID: 21130333 DOI: 10.1016/j.ajodo.2008.12.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2008] [Revised: 12/01/2008] [Accepted: 12/01/2008] [Indexed: 11/22/2022]
|
180
|
Reis AF, Carrilho MRO, Ghaname E, Pereira PNR, Giannini M, Nikaido T, Tagami J. Effects of water-storage on the physical and ultramorphological features of adhesives and primer/adhesive mixtures. Dent Mater J 2010; 29:697-705. [PMID: 21099154 DOI: 10.4012/dmj.2009-091] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aims of this study were to evaluate the ultimate tensile strength (UTS) and elastic modulus (E) of adhesives, and primer/adhesive mixtures after aging for 6 months in water or oil; and to compare silver uptake patterns under the TEM. A one-step self-etching adhesive (One-up Bond F: OB), two two-step self-etching primers (SE Bond: SE and Protect Bond: CP), and two etch-and-rinse systems (Single Bond: SB and Prime&Bond NT: PB) were used. Bonding and primer solutions of self-etching systems were also mixed (SE+P and CP+P). Most adhesives presented decreased UTS after water-storage. Similar or increased UTS was observed after oil storage. Except for SB, E values did not change after water-storage, but they increased after storage in oil. OB, CP+P and SE+P presented more silver uptake. The effects of water-storage were material-dependent, and significantly affected the mechanical properties and silver uptake patterns of adhesives.
Collapse
Affiliation(s)
- Andre F Reis
- Department of Operative Dentistry, Guarulhos University, SP, Brazil
| | | | | | | | | | | | | |
Collapse
|
181
|
Kopperud HM, Kleven IS, Wellendorf H. Identification and quantification of leachable substances from polymer-based orthodontic base-plate materials. Eur J Orthod 2010; 33:26-31. [PMID: 20624754 DOI: 10.1093/ejo/cjq020] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The aim of this study was to analyse leachable monomers, additives, and degradation products from polymer-based orthodontic base-plate materials. One heat-cured resin (Orthocryl), one light-cured (Triad VLC), and three thermoplastic materials (Biocryl C, Essix A+, and Essix Embrace) were investigated. Elution was performed in water at 37°C for 10 days. The extract medium was changed and analysed daily. Chromatographic methods were used to identify and quantify the leachables. In addition, the content of residual methyl methacrylate (MMA) was quantified in the poly(methyl methacrylate) (PMMA)-based materials. Statistical analysis of the quantitative results was performed using a t-test for comparison of two independent samples. Monomers and additives leached from the materials polymerized in situ and from the thermoplastic PMMA-based material. No leachable substances were found in the extracts from the other thermoplastic materials. Accumulated over 10 days, a larger amount of MMA leached from the powder-and-liquid material, Orthocryl (42 μg/cm(2)), than from the thermoplastic material, Biocryl C (0.49 μg/cm(2)). The accumulated amounts of monomers leached from Triad VLC were 91 μg/cm(2) of urethane dimethacrylate and 2.2 μg/cm(2) of 2-hydroxyethyl methacrylate. Formaldehyde was found to leach from methacrylate-based materials: 3.2 μg/cm(2) from Orthocryl and 0.16 μg/cm(2) from Triad VLC. However, formaldehyde was not detectable in extracts from Biocryl C. Residual MMA was 5.4 wt % in Orthocryl and 0.4 wt % in Biocryl C. No phthalates were detected in the tested materials. In this in vitro study, minimal leaching was found from the thermoplastic materials, while leaching of methacrylates and formaldehyde was observed from the powder-and-liquid type and the paste material. Within the limitations of this study, the results suggest that prefabricated thermoplastic plates should be preferred for patients with an allergy to methacrylates.
Collapse
|
182
|
Durner J, Glasl B, Zaspel J, Kunzelmann K, Hickel R, Reichl F. Release of TEGDMA from composite during the chewing situation. Dent Mater 2010; 26:e197-204. [DOI: 10.1016/j.dental.2010.03.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2009] [Revised: 11/27/2009] [Accepted: 03/05/2010] [Indexed: 10/19/2022]
|
183
|
Pires-de-Souza FDCP, de Marco FF, Casemiro LA, Panzeri H. Desensitizing bioactive agents improves bond strength of indirect resin-cemented restorations: preliminary results. J Appl Oral Sci 2010; 15:120-6. [PMID: 19089114 PMCID: PMC4327242 DOI: 10.1590/s1678-77572007000200009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2006] [Accepted: 03/02/2007] [Indexed: 11/22/2022] Open
Abstract
Objective: The aim of this study was to assess the bond strength of indirect composite restorations cemented with a resin-based cement associated with etch-and-rinse and self-etching primer adhesive systems to dentin treated or not with a bioactive material. Materials and Method: Twenty bovine incisor crowns had the buccal enamel removed and the dentin ground flat. The teeth were assigned to 4 groups (n=5): Group I: acid etching + Prime & Bond NT (Dentsply); Group II: application of a bioactive glass (Biosilicato®)+ acid etching + Prime & Bond NT; Group III: One-up Bond F (J Morita); Group IV: Biosilicato® + One-up Bond F. Indirect composite resin (Artglass, Kulzer) cylinders (6x10mm) were fabricated and cemented to the teeth with a dualcure resin-based cement (Enforce, Dentsply). After cementation, the specimens were stored in artificial saliva at 37oC for 30 days and thereafter tested in tensile strength in a universal testing machine (EMIC) with 50 kgf load cell at a crosshead speed of 1 mm/min. Failure modes were assessed under scanning electron microscopy. Data were analyzed statistically by ANOVA and Tukey's test (95% level of confidence). Results: Groups I, II and III had statistically similar results (p>0.05). Group IV had statistically significant higher bond strength means (p<0.05) than the other groups. The analysis of the debonded surfaces showed a predominance of adhesive failure mode for Group III and mixed failure mode for the other groups. Conclusion: The use of desensitizing agent did not affect negatively the bonding of the indirect composite restorations to dentin, independently of the tested adhesive systems.
Collapse
|
184
|
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.
Collapse
Affiliation(s)
- Paulette Spencer
- Department of Mechanical Engineering, University of Kansas, 1530 W 15th St, Lawrence, KS 66045, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
185
|
|
186
|
Kermanshahi S, Santerre JP, Cvitkovitch DG, Finer Y. Biodegradation of resin-dentin interfaces increases bacterial microleakage. J Dent Res 2010; 89:996-1001. [PMID: 20505047 DOI: 10.1177/0022034510372885] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Bis-GMA-containing resin composites and adhesives undergo biodegradation by human-saliva-derived esterases, yielding Bis-hydroxy-propoxy-phenyl-propane (Bis-HPPP). The hypothesis of this study is that the exposure of dental restorations to saliva-like esterase activities accelerates marginal bacterial microleakage. Resin composites (Scotchbond, Z250, 3M) bonded to human dentin were incubated in either buffer or dual-esterase media (pseudocholinesterase/cholesterol-esterase; PCE+CE), with activity levels simulating those of human saliva, for up to 90 days. Incubation solutions were analyzed for Bis-HPPP by high-performance liquid chromatography. Post-incubation, specimens were suspended in a chemostat-based biofilm fermentor cultivating Streptococcus mutans NG8, a primary species associated with dental caries, for 7 days. Bacterial microleakage was assessed by confocal laser scanning microscopy. Bis-HPPP production and depth and spatial volume of bacterial cell penetration within the interface increased with incubation time and were higher for 30- and 90-day PCE+CE vs. buffer-incubated groups, suggesting that biodegradation can contribute to the formation of recurrent decay.
Collapse
Affiliation(s)
- S Kermanshahi
- Biomaterials Discipline, Dental Research Institute, Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON, Canada M5G 1G6
| | | | | | | |
Collapse
|
187
|
Bettencourt AF, Neves CB, de Almeida MS, Pinheiro LM, Oliveira SAE, Lopes LP, Castro MF. Biodegradation of acrylic based resins: A review. Dent Mater 2010; 26:e171-80. [DOI: 10.1016/j.dental.2010.01.006] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 09/29/2009] [Accepted: 01/13/2010] [Indexed: 11/25/2022]
|
188
|
Loguercio AD, Mânica D, Ferneda F, Zander-Grande C, Amaral R, Stanislawczuk R, Carvalho RM, Manso A, Reis A. A Randomized Clinical Evaluation of a One- and Two-step Self-etch Adhesive Over 24 Months. Oper Dent 2010; 35:265-72. [DOI: 10.2341/09-241-c] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
The application of an extra hydrophobic bond layer over the self-etch adhesive system improved clinical performance over a 24-month period, mainly in terms of retention rate.
Collapse
|
189
|
Reis A, Klein-Júnior CA, de Souza FHC, Stanislawczuk R, Loguercio AD. The use of warm air stream for solvent evaporation: effects on the durability of resin-dentin bonds. Oper Dent 2010; 35:29-36. [PMID: 20166408 DOI: 10.2341/08-065-l] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study evaluated the effect of a warm (W) or cold (C) air-dry stream for solvent evaporation on the immediate (IM) and six-month (6M) resin-dentin bond strength (microTBS) and silver nitrate uptake pattern (SNU) of two-step etch-and-rinse adhesive system (Adper Single Bond [SB] and Prime & Bond 2.1 [PB]). The adhesives were applied on demineralized dentin surfaces and a warm or cold air-dry stream (10 seconds) was applied followed by light-activation (10 seconds). After 24-hours of water storage, the specimens were serially sectioned in the "x" and "y" directions to obtain bonded sticks around 0.8 mm2 to be tested immediately or after six months of water storage. The specimens at each period were immersed in a 50% solution of silver nitrate, photodeveloped and analyzed by SEM for SNU. Higher IM microTBS values were observed for SB under W conditions. Both adhesives showed reductions in microTBS after 6M in both air temperatures. Regarding SEM, a low silver nitrate uptake was observed in the W groups either in IM or 6M for both adhesives.
Collapse
Affiliation(s)
- Alessandra Reis
- Department of Restorative Dentistry, Universidade Estadual de Ponta Grossa, Ponta Grossa, PR, Brazil
| | | | | | | | | |
Collapse
|
190
|
Critical Review on Methacrylate Resin–based Root Canal Sealers. J Endod 2010; 36:383-99. [DOI: 10.1016/j.joen.2009.10.023] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Revised: 10/13/2009] [Accepted: 10/18/2009] [Indexed: 10/20/2022]
|
191
|
Pawlowska E, Poplawski T, Ksiazek D, Szczepanska J, Blasiak J. Genotoxicity and cytotoxicity of 2-hydroxyethyl methacrylate. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2010; 696:122-9. [DOI: 10.1016/j.mrgentox.2009.12.019] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 11/25/2009] [Accepted: 12/28/2009] [Indexed: 01/22/2023]
|
192
|
Kececi AD, Kaya BU, Belli S. Corono-apical leakage of various root filling materials using two different penetration modelsâA 3-month study. J Biomed Mater Res B Appl Biomater 2010; 92:261-7. [DOI: 10.1002/jbm.b.31513] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
193
|
Poplawski T, Loba K, Pawlowska E, Szczepanska J, Blasiak J. Genotoxicity of urethane dimethacrylate, a tooth restoration component. Toxicol In Vitro 2009; 24:854-62. [PMID: 20005290 DOI: 10.1016/j.tiv.2009.12.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 11/26/2009] [Accepted: 12/03/2009] [Indexed: 01/15/2023]
Abstract
Urethane dimethacrylate (UDMA) is used in dental restorative materials in its polymeric form. However, the process of polymerization is usually incomplete and the monomers of UDMA can diffuse into the oral cavity and the pulp, reaching millimolar concentrations. In the present work we showed that UDMA at 0.1 and 1.0 mM decreased the viability of and induced DNA damage in lymphocytes in a concentration dependent manner, but it did not affect a plasmid DNA in vitro. UDMA at 1mM induced apoptosis in lymphocytes. The lymphocytes exposed to UDMA were able to repair their DNA within 60 min. Analysis with DNA repair enzymes Endo III and Fpg showed that UDMA induced mainly oxidative DNA lesions. Vitamin C and chitosan decreased genotoxic effect of UDMA. Our results show that monomers of UDMA may exert pronounced cyto- and genotoxic effects in human lymphocytes and chitosan can be considered as a protection against such effects.
Collapse
Affiliation(s)
- Tomasz Poplawski
- Department of Molecular Genetics, University of Lodz, Banacha 12/16, 90-237 Lodz, Poland
| | | | | | | | | |
Collapse
|
194
|
Improving clinical retention of one-step self-etching adhesive systems with an additional hydrophobic adhesive layer. J Am Dent Assoc 2009; 140:877-85. [PMID: 19571051 DOI: 10.14219/jada.archive.2009.0281] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The durability of restorations bonded with one-step self-etching (OSSE) adhesive systems is inferior compared with that of restorations bonded with conventional adhesives. The authors conducted an 18-month randomized clinical study to evaluate the clinical performance of two OSSE systems in noncarious cervical lesions applied as recommended or with an extra layer of hydrophobic adhesive layer after 18 months of clinical service. METHODS Thirty participants, each of whom had at least two pairs of similar-sized noncarious cervical lesions, took part in this study. The authors placed 120 restorations, 30 in each of four groups: Clearfil S3 Bond (Kuraray, Osaka, Japan) (CS) and iBond Gluma inside (Heraeus Kulzer, Hanau, Germany) (IB), and Clearfil S3 Bond (CSB) and iBond Gluma inside (IBB) with an extra layer of hydrophobic adhesive applied on top of them. They placed the restorations incrementally, using a resin-based composite. The authors evaluated the restorations at baseline and at 18 months following modified U.S. Public Health Service criteria. RESULTS At 18 months, the retention rate for the IB group was statistically lower than those for the CS, IBB and CSB groups. Marginal discoloration occurred in all groups and was statistically worse in the IB group. CONCLUSIONS The conversion of the iBond Gluma inside and Clearfil S3 Bond adhesive systems into two-step systems by means of applying an extra hydrophobic adhesive layer improved the clinical performance of these materials after 18 months of clinical service. CLINICAL IMPLICATIONS The application of an extra hydrophobic adhesive layer over OSSE adhesive systems, layers improved the OSSE systems clinical performance, mainly in terms of retention rate.
Collapse
|
195
|
Park JG, Ye Q, Topp EM, Lee CH, Kostoryz EL, Misra A, Spencer P. Dynamic mechanical analysis and esterase degradation of dentin adhesives containing a branched methacrylate. J Biomed Mater Res B Appl Biomater 2009; 91:61-70. [PMID: 19358261 PMCID: PMC2990471 DOI: 10.1002/jbm.b.31374] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A study of the dynamic mechanical properties and the enzymatic degradation of new dentin adhesives containing a multifunctional methacrylate are described. Adhesives contained 2-hydroxyethyl methacrylate, 2,2-bis[4-(2-hydroxy-3-methacryloxypropoxy) phenyl]-propane, and a new multifunctional methacrylate with a branched side chain-trimethylolpropane mono allyl ether dimethacrylate (TMPEDMA). Adhesives were photopolymerized in the presence of 0, 8, and 16 wt % water to simulate wet bonding conditions in the mouth and compared with control adhesives. The degree of conversion as a function of irradiation time was comparable for experimental and control adhesives. In dynamic mechanical analysis, broad tan delta peaks were obtained for all samples, indicating that the polymerized networks are heterogeneous; comparison of the full-width-at-half-maximum values obtained from the tan delta curves indicated increased heterogeneity for samples cured in the presence of water and/or containing TMPEDMA. The experimental adhesive showed higher T(g) and higher rubbery modulus indicating increased crosslink density when compared with the control. The improvement in esterase resistance afforded by adhesives containing the TMPEDMA is greater when this material is photopolymerized in the presence of water, suggesting better performance in the moist environment of the mouth. The improved esterase resistance of the new adhesive could be explained in terms of the densely crosslinked network structure and/or the steric hindrance of branched alkyl side chains.
Collapse
Affiliation(s)
- Jong-Gu Park
- Bioengineering Research Center, University of Kansas, Lawrence, Kansas, USA
| | | | | | | | | | | | | |
Collapse
|
196
|
Seiss M, Langer C, Hickel R, Reichl FX. Quantitative determination of TEGDMA, BHT, and DMABEE in eluates from polymerized resin-based dental restorative materials by use of GC/MS. Arch Toxicol 2009; 83:1109-15. [DOI: 10.1007/s00204-009-0470-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2008] [Accepted: 09/03/2009] [Indexed: 01/12/2023]
|
197
|
Bakopoulou A, Papadopoulos T, Garefis P. Molecular toxicology of substances released from resin-based dental restorative materials. Int J Mol Sci 2009; 10:3861-3899. [PMID: 19865523 PMCID: PMC2769064 DOI: 10.3390/ijms10093861] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 08/24/2009] [Accepted: 09/02/2009] [Indexed: 01/22/2023] Open
Abstract
Resin-based dental restorative materials are extensively used today in dentistry. However, significant concerns still remain regarding their biocompatibility. For this reason, significant scientific effort has been focused on the determination of the molecular toxicology of substances released by these biomaterials, using several tools for risk assessment, including exposure assessment, hazard identification and dose-response analysis. These studies have shown that substances released by these materials can cause significant cytotoxic and genotoxic effects, leading to irreversible disturbance of basic cellular functions. The aim of this article is to review current knowledge related to dental composites' molecular toxicology and to give implications for possible improvements concerning their biocompatibility.
Collapse
Affiliation(s)
- Athina Bakopoulou
- Department of Fixed & Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece; E-Mails: (B.A.); (G.P.)
| | - Triantafillos Papadopoulos
- Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Athens, 115 27, Greece
| | - Pavlos Garefis
- Department of Fixed & Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece; E-Mails: (B.A.); (G.P.)
| |
Collapse
|
198
|
Brambilla E, Gagliani M, Ionescu A, Fadini L, García-Godoy F. The influence of light-curing time on the bacterial colonization of resin composite surfaces. Dent Mater 2009; 25:1067-72. [DOI: 10.1016/j.dental.2009.02.012] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Revised: 02/02/2009] [Accepted: 02/02/2009] [Indexed: 11/17/2022]
|
199
|
de Andrade e Silva SM, Carrilho MRDO, Marquezini Junior L, Garcia FCP, Manso AP, Alves MC, de Carvalho RM. Effect of an additional hydrophilic versus hydrophobic coat on the quality of dentinal sealing provided by two-step etch-and-rinse adhesives. J Appl Oral Sci 2009; 17:184-9. [PMID: 19466248 PMCID: PMC4399529 DOI: 10.1590/s1678-77572009000300010] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Accepted: 09/22/2008] [Indexed: 11/22/2022] Open
Abstract
Objective: To test the hypothesis that the quality of the dentinal sealing provided by two-step etch-and-rinse adhesives cannot be altered by the addition of an extra layer of the respective adhesive or the application of a more hydrophobic, non-solvated resin. Material and Methods: full-crown preparations were acid-etched with phosphoric acid for 15 s and bonded with Adper Single Bond (3M ESPE), Excite DSC (Ivoclar/Vivadent) or Prime & Bond NT (Dentsply). The adhesives were used according to the manufacturers' instructions (control groups) or after application to dentin they were a) covered with an extra coat of each respective system or b) coated with a non-solvated bonding agent (Adper Scotchbond Multi-Purpose Adhesive, 3M ESPE). Fluid flow rate was measured before and after dentin surfaces were acid-etched and bonded with adhesives. Results: None of the adhesives or experimental treatments was capable to block completely the fluid transudation across the treated dentin. Application of an extra coat of the adhesive did not reduce the fluid flow rate of adhesive-bonded dentin (p>0.05). Conversely, the application of a more hydrophobic non-solvated resin resulted in significant reductions in the fluid flow rate (p<0.05) for all tested adhesives. Conclusions: The quality of the dentinal sealing provided by etch-and-rinse adhesives can be significantly improved by the application of a more hydrophobic, non-solvated bonding agent.
Collapse
Affiliation(s)
- Safira Marques de Andrade e Silva
- Department of Restorative Dentistry and Dental Materials, Dental School of Piracicaba, University of Campinas, Piracicaba, SP, Brazil
| | | | | | | | | | | | | |
Collapse
|
200
|
Reis A, Moura K, Pellizzaro A, Dal-Bianco K, de Andrade AM, Loguercio AD. Durability of enamel bonding using one-step self-etch systems on ground and unground enamel. Oper Dent 2009; 34:181-91. [PMID: 19363974 DOI: 10.2341/08-58] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To examine the morphological, early and long-term microtensile bond strengths (microTBS) of one-step self-etch systems to unground and ground enamel. MATERIALS AND METHODS Resin composite (Filtek Z250) buildups were bonded to the buccal and lingual enamel surfaces (unground, bur-cut or SiC-roughened enamel) of third molars after adhesive application using the following adhesives: Clearfil S3 Bond (CS3); Adper Prompt L-Pop (ADP); iBond (iB) and, as the control, Clearfil SE Bond (CSE). Six tooth halves were assigned for each condition. After storage in water (24 hours/37 degrees C), the bonded specimens were sectioned into beams (0.8 mm2) and subjected to microTBS (0.5 mm/min) either immediately (IM) or after six (6 M) or 12 months (12 M) of water storage. The data were analyzed by three-way repeated measures ANOVA and Tukey's test (alpha = 0.05). Surface conditioning was observed under scanning electron microscopy (SEM). RESULTS The microTBS in the Si-C paper and diamond bur groups were similar and higher than the unground group. No significant difference was observed among the different storage periods, except for CS3, which showed an increase in the microTBS after 12 M. The etching pattern was more retentive on ground enamel. CONCLUSIONS One-step self-etch adhesives showed higher bond strengths on ground enamel and no reductions in resin-enamel bonds were observed after 12 M of water storage.
Collapse
Affiliation(s)
- Alessandra Reis
- Department of Restorative Dentistry, School of Dentistry, University Estadual de Ponta Grossa, Ponta Grossa/PR, Brazil.
| | | | | | | | | | | |
Collapse
|