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Klimek L. [Allergic reactions to bioimplants]. HNO 2022; 70:361-370. [PMID: 35344067 DOI: 10.1007/s00106-022-01173-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2022] [Indexed: 11/29/2022]
Abstract
BACKGROUND Bioimplants are used in a variety of ways in otorhinolaryngology, most commonly in facial reconstructive surgery, cochlear implants (CI), bone-anchored hearing aids, and partial/total ossicular replacement prostheses (PORP/TORP), but also for tympanic drainage, laryngeal cannula, voice prostheses after laryngectomy, etc., and in otorhinolaryngology-related procedures as dental implants in dentistry. METHODS A literature search was performed to analyze the immunology of allergic reactions to bioimplants and to determine the available evidence by searching Medline, PubMed, and national and international study and guideline registries and the Cochrane Library. Human studies published in the period up to and including 12/2021 were considered. RESULTS Based on the international literature and previous experience, a review of allergies to bioimplants in otolaryngology is presented. CONCLUSION Otorhinolaryngologists should always consider the possibility of allergic reactions when inserting allogeneic materials, particularly, but not only, when using bioimplants.
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Affiliation(s)
- L Klimek
- Zentrum für Rhinologie und Allergologie, An den Quellen 10, 65183, Wiesbaden, Deutschland.
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Wedekind L, Güth JF, Schweiger J, Kollmuss M, Reichl FX, Edelhoff D, Högg C. Elution behavior of a 3D-printed, milled and conventional resin-based occlusal splint material. Dent Mater 2021; 37:701-10. [PMID: 33648744 DOI: 10.1016/j.dental.2021.01.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 12/12/2020] [Accepted: 01/20/2021] [Indexed: 12/21/2022]
Abstract
OBJECTIVE The elution of unpolymerized (co-)monomers and additives from methacrylic resin-based materials like polymethyl methacrylate (PMMA) can cause adverse side effects, such as mutagenicity, teratogenicity, genotoxicity, cytotoxicity and estrogenic activity. The aim of this study was to quantify the release and the cytotoxicity of residual (co-)monomers and additives from PMMA-based splint materials under consideration of real splint sizes. Three different materials used for additive (3D printing), subtractive (milling) and conventional (powder and liquid) manufacturing were examined. METHODS The splint materials SHERAprint-ortho plus (additive), SHERAeco-disc PM20 (subtractive) and SHERAORTHOMER (conventional) were analysed. 16 (n = 4) sample discs of each material (6 mm diameter and 2 mm height) were polished on the circular and one cross-section area and then eluted in both distilled water and methanol. The discs were incubated at 37 °C for 24 h or 72 h and subsequently analysed by gas chromatography/mass spectrometry (GC/MS) for specifying and quantifying released compounds. XTT-based cell viability assays with human gingival fibroblasts (HGFs) were performed for Tetrahydrofurfuryl methacrylate (THFMA), 1,4-Butylene glycol dimethacrylate (BDDMA) and Tripropylenglycol diacrylate (TPGDA). In order to project the disc size to actual splint sizes in a worst-case scenario, lower and upper jaw occlusal splints were designed and volumes and surfaces were measured. RESULTS For SHERAeco-disc PM20 and for SHERAORTHOMER no elution was determined in water. SHERAprint-ortho plus eluted the highest THFMA concentration of 7.47 μmol/l ±2,77 μmol/l after 72 h in water. Six (co-)monomers and five additives were detected in the methanol eluates of all three materials tested. The XTT-based cell viability assays resulted in a EC50 of 3006 ± 408 μmol/l for THFMA, 2569.5 ± 308 μmol/l for BDDMA and 596.7 ± 88 μmol/l for TPGDA. SIGNIFICANCE With the solvent methanol, released components from the investigated splint materials exceeded cytotoxic concentrations in HGFs calculated for a worst-case scenario in splint size. In the water eluates only the methacrylate THFMA could be determined from SHERAprint-ortho plus in concentrations below cytotoxic levels in HGFs.
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Cimatu KLA, Premadasa UI, Ambagaspitiya TD, Adhikari NM, Jang JH. Evident phase separation and surface segregation of hydrophobic moieties at the copolymer surface using atomic force microscopy and SFG spectroscopy. J Colloid Interface Sci 2020; 580:645-659. [PMID: 32712471 DOI: 10.1016/j.jcis.2020.07.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/12/2020] [Accepted: 07/13/2020] [Indexed: 11/18/2022]
Abstract
HYPOTHESIS Copolymers are developed to enhance the overall physical and chemical properties of polymers. The surface nature of a copolymer is relevant to creating efficient materials to improve adhesion and biocompatibility. We hypothesize that the improved adhesion, as a surface property, is due to phase separation, surface segregation, and the overall molecular organization of different polymer components at the copolymer surface. EXPERIMENTS The surface structure of a copolymer composed of 2-hydroxyethyl methacrylate (HEMA) monomer and 2-phenoxyethyl methacrylate (PhEMA) monomer was analyzed in comparison to the polyHEMA and polyPhEMA homopolymers using atomic force microscopy (AFM) and sum frequency generation (SFG) spectroscopy. FINDINGS The contrast in the phase images was due to the variance in the hydrophobic level provided by the hydroxyl and phenoxy modified monomers in the copolymer. The distribution of the adhesion values, supporting the presence of hydrophobic moieties, across the polymer surface defined the surface segregation of these two components. SFG spectra of the copolymer thin film showed combined spectral features of both polyHEMA and polyPhEMA thin films at the polymer surface. The tilt angles of the alpha-methyl group of homopolymers using the polarization intensity ratio analysis and the polarization mapping method were estimated to be in the range from 48° to 66°.
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Affiliation(s)
- Katherine Leslee A Cimatu
- Department of Chemistry and Biochemistry, Ohio University, 100 University Terrace, 136 Clippinger Laboratories, Athens, OH 45701-2979, United States.
| | - Uvinduni I Premadasa
- Department of Chemistry and Biochemistry, Ohio University, 100 University Terrace, 136 Clippinger Laboratories, Athens, OH 45701-2979, United States
| | - Tharushi D Ambagaspitiya
- Department of Chemistry and Biochemistry, Ohio University, 100 University Terrace, 136 Clippinger Laboratories, Athens, OH 45701-2979, United States
| | - Narendra M Adhikari
- Department of Chemistry and Biochemistry, Ohio University, 100 University Terrace, 136 Clippinger Laboratories, Athens, OH 45701-2979, United States
| | - Joon Hee Jang
- Department of Nanomedicine, Houston Methodist Research Institute, 6670 Bertner Avenue, Houston, TX 77030, United States
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Kimber I. The activity of methacrylate esters in skin sensitisation test methods II. A review of complementary and additional analyses. Regul Toxicol Pharmacol 2020; 119:104821. [PMID: 33186628 DOI: 10.1016/j.yrtph.2020.104821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/29/2020] [Accepted: 11/05/2020] [Indexed: 01/13/2023]
Abstract
Allergic contact dermatitis is an important occupational health issue, and there is a need to identify accurately those chemicals that have the potential to induce skin sensitisation. Hazard identification was performed initially using animal (guinea pig and mouse) models. More recently, as a result of the drive towards non-animal methods, alternative in vitro and in silico approaches have been developed. Some of these new in vitro methods have been formally validated and have been assigned OECD Test Guideline status. The performance of some of these recently developed in vitro methods, and of 2 quantitative structure-activity relationships (QSAR) approaches, with a series of methacrylate esters has been reviewed and reported previously. In this article that first review has been extended further with additional data and complementary analyses. Results obtained using in vitro methods (Direct Peptide Reactivity Assay, DPRA; ARE-Nrf2 luciferase test methods, KeratinoSens and LuSens; Epidermal Sensitisation Assay, EpiSensA; human Cell Line Activation Test, h-CLAT, and the myeloid U937 Skin Sensitisation test, U-SENS), and 2 QSAR approaches (DEREK™-nexus and TIMES-SS), with 11 methacrylate esters and methacrylic acid are reported here, and compared with existing data from the guinea pig maximisation test and the local lymph node assay. With this series of chemicals it was found that some in vitro tests (DPRA and ARE-Nrf2 luciferase) performed well in comparison with animal test results and available human skin sensitisation data. Other in vitro tests (EpiSensA and h-CLAT) proved rather more problematic. Results with DEREK™-nexus and TIMES-SS failed to reflect accurately the skin sensitisation potential of the methacrylate esters. The implications for assessment of skin sensitising activity are discussed.
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Affiliation(s)
- Ian Kimber
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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Guimarães GMF, Bronze-Uhle ES, Lisboa-Filho PN, Fugolin APP, Borges AFS, Gonzaga CC, Pfeifer CS, Furuse AY. Effect of the addition of functionalized TiO 2 nanotubes and nanoparticles on properties of experimental resin composites. Dent Mater 2020; 36:1544-56. [PMID: 33012518 DOI: 10.1016/j.dental.2020.09.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2020] [Revised: 06/29/2020] [Accepted: 09/10/2020] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To evaluate the influence of the addition of functionalized and non-functionalized TiO2 nanostructures on properties of a resin composite. METHODS TiO2 nanostructures were synthesized and functionalized, using 3-(aminopropyl)triethoxysilane (APTMS) and 3-(trimethoxysilyl)propyl methacrylate (TSMPM). Characterizations were performed with XRD, EDS, TEM, and TGA. Resin composites containing Bis-GMA/TEGDMA, CQ, DABE, and barium-aluminum silicate glass were produced according to TiO2 nanostructure (nanotube or nanoparticle), concentration (0.3 or 0.9 wt%), and functionalization (APTMS or TSMPM). The resin composite without nanostructures was used as control. The amount of fillers was kept constant at 78.3 wt% for all materials. The degree of conversion (DC - at 0 h and 24 h), maximum polymerization rate (Rpmax), and Knoop microhardness (KHN before and after ethanol softening) were evaluated. Data were analyzed with two-way ANOVA with repeated measures and Tukey's HSD (α = 0.05). RESULTS TGA results demonstrated that functionalizations were effective for both nanostructures. For DC, resin composites, time and interaction effect were significant (p < 0.001). Higher DC was found for 0.3-wt%-functionalized-nanotubes at 24 h. For nanoparticles, only 0.9-wt%-non-functionalized and 0.3-wt%-APTMS-functionalized showed DC similar to the control and all other groups showed higher DC (p < 0.05). Rpmax was higher for 0.3-wt%-APTMS-nanotubes, which corresponded to higher DC after 24 h. The lowest Rpmax occurred for 0.9-wt%-TSMPM-nanotubes, which showed smaller DC at 0 h. For KHN, resin composites, ethanol softening and interaction effect were significant (p < 0.001). KHN decreased after ethanol softening all groups, except for 0.3-wt%-TSMPM-nanotubes, 0.9-wt%-TSMPM-nanotubes, and 0.3-wt%-non-functionalized-nanoparticles. CONCLUSION The resin with 0.3-wt%-TSMPM-nanotubes showed higher DC after 24 h, while being the most stable material after the ethanol softening. SIGNIFICANCE The addition of functionalized TiO2 nanostructures in resin-based materials may improve the properties of the material.
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Taubmann A, Willershausen I, Walter C, Al-Maawi S, Kaina B, Gölz L. Genotoxic and cytotoxic potential of methacrylate-based orthodontic adhesives. Clin Oral Investig 2020; 25:2569-2581. [PMID: 32970196 PMCID: PMC8060203 DOI: 10.1007/s00784-020-03569-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 09/03/2020] [Indexed: 01/01/2023]
Abstract
Objectives The biocompatibility of methacrylate-based adhesives is a topic that is intensively discussed in dentistry. Since only limited evidence concerning the cyto- and genotoxicity of orthodontic adhesives is available, the aim of this study was to measure the genotoxic potential of seven orthodontic methacrylate-based adhesives. Materials and methods The XTT assay was utilized to determine the cytotoxicity of Assure Plus, Assure Bonding Resin, ExciTE F, OptiBond Solo Plus, Scotchbond Universal Adhesive, Transbond MIP, and Transbond XT after an incubation period of 24 h on human gingival fibroblasts. We also performed the γH2AX assay to explore the genotoxic potential of the adhesives within cytotoxic dose ranges after an incubation period of 6 h. Results The XTT assay showed a concentration-dependent reduction in cell viability. The decrease in cellular viability was in the same dose range most significant for Assure Plus, rendering it the adhesive material with the highest cytotoxicity. Employing the γH2AX assay, a concentration-dependent increase in H2AX phosphorylation was detected, indicating induction of DNA damage. Conclusions For most products, a linear correlation between the material concentration and γH2AX foci was observed. The most severe effect on γH2AX focus induction was found for Transbond MIP, which was the only adhesive in the test group containing the co-initiator diphenyliodonium hexafluorophosphate (DPIHP). Clinical relevance The data indicate that orthodontic adhesives, notably Transbond MIP, bear a genotoxic potential. Since the study was performed with in vitro cultivated cells, a direct translation of the findings to in vivo exposure conditions should be considered with great diligence.
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Affiliation(s)
- Andreas Taubmann
- Department of Operative Dentistry, Johannes Gutenberg University Hospital Mainz, Mainz, Germany
| | - Ines Willershausen
- Department of Orthodontics and Orofacial Orthopedics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany.
| | | | - Sarah Al-Maawi
- Frankfurt Orofacial Regenerative Medicine (FORM) Lab, Department for Oral, Cranio-Maxillofacial and Facial Plastic Surgery, Medical Center of the Goethe University Frankfurt, Frankfurt/Main, Germany
| | - Bernd Kaina
- Institute of Toxicology, University Medical Center Mainz, Mainz, Germany
| | - Lina Gölz
- Department of Orthodontics and Orofacial Orthopedics, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany
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Kessler A, Reichl FX, Folwaczny M, Högg C. Monomer release from surgical guide resins manufactured with different 3D printing devices. Dent Mater 2020; 36:1486-92. [PMID: 32972769 DOI: 10.1016/j.dental.2020.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/03/2020] [Indexed: 11/21/2022]
Abstract
OBJECTIVES The aim of this study was to assess the post curing monomer release of resins applicable for 3D printing of surgical implant guides in dependency of printing technique and storing media using high performance liquidchromatography. MATERIAL AND METHODS Specimens of Nextdent SG, Freeprint Splint, Fotodent Guide, 3Delta Guide, and V-print SG (n = 4) were additively manufactured with the corresponding DLP/SLA printing devices (Rapidshape D20II, Form2, Solflex350). Postprocessing was done according to the manufacturer's specifications. Subsequently, samples were eluted in methanol and water for 3 days and analyzed with gas chromatography/mass spectrometry (GC/MS). RESULTS A total of twelve different substances released from the tested resin materials. The highest eluted concentration for MMA in methanol was 20.27 ± 8.60 μg/mL followed by 12.66 ± 3.38 μg/mL of HPMA. HEMA was found at concentration of 11.17 ± 2.43 μg/mL in methanol and 1.15 ± 0.11 μg/mL in water. TPGDA and TEGDMA reached maximum concentration in methanol of 4.29 ± 0.54 μg/mL and 5.07 ± 0.93 μg/mL and in water of 0.79 ± 0.19 μg/mL and 0.36 ± 0.14 μg/mL, respectively. Significant difference was found for the material Nextdent SG manufactured on SLA and DLP printing device for THFMA (p = 0.041), TEGDMA (p = 0.026), TPGDA (p = 0.05) and EGDMA (p = 0.06). The amount of monomers released into water did not reach the detection threshold for V-print SG. SIGNIFICANCE The study revealed significant influence of the printing technique and resin material on the elution of monomers. The elution in methanol and water was significantly different. While the relative amount of eluted monomers from 3D printed guides is comparable to conventional direct composites and below toxic relevant concentrations, the absolute amount of monomer can rise in a clinic situation due to the size of the guides.
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Nakanishi L, Kaizer MR, Brandeburski S, Cava SS, Della Bona A, Zhang Y, Moraes RR. Non-silicate nanoparticles for improved nanohybrid resin composites. Dent Mater 2020; 36:1314-21. [PMID: 32758374 DOI: 10.1016/j.dental.2020.07.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 07/11/2020] [Accepted: 07/11/2020] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Zirconia and alumina nanoparticles were coated with a silica-rich layer (ALSI and ZRSI) and used to prepare experimental nanohybrid resin composites, which were characterized and compared to a control commercial resin composite (Filtek Z350 XT). METHODS Silica nanoparticles with sizes compatible to ALSI (Aerosil 150) and ZRSI (Aerosil OX 50) were tested as references. The volume of nanoparticles was equivalent across the composites, which also had consistent content of glass microparticles. CC conversion, viscosity, depth of cure, surface topography, hardness, opacity, radio-opacity, and edge chipping resistance (ReA) were tested after 24 h. Flexural strength (σf) and fracture toughness (KIC) were also tested after 15 K thermal cycles. Data were analyzed using one-way or two-way ANOVA and Tukey's test (α = 0.05). RESULTS ALSI and ZRSI yielded resin composites with lower viscosity and more irregular nanoagglomerates compared to nanosilica-based composites. CC conversion and depth of cure were lower for ZRSI composite, which had higher opacity, radio-opacity, and hardness. ReA was higher for ALSI composite. Composites with ALSI and ZRSI showed stable σf after aging, whereas the control and Aerosil 150 resin composites showed significant degradation. The commercial and nanosilica-based composites showed up to 42% reduction in KIC after aging, whereas resin composites with ZRSI and ALSI showed a more stable KIC. SIGNIFICANCE ALSI and ZRSI generated nanohybrid resin composites with improved and/or more stable physical properties compared with nanosilica-based and commercial composites. This study suggests that changing the composition of nanofillers is a simple method to enhance the performance of nanohybrid composites.
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Kirschner J, Szillat F, Bouzrati-Zerelli M, Becht JM, Klee JE, Lalevée J. Sulfinates and sulfonates as high performance co-initiators in CQ based systems: Towards aromatic amine-free systems for dental restorative materials. Dent Mater 2019; 36:187-196. [PMID: 31791740 DOI: 10.1016/j.dental.2019.11.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Revised: 10/27/2019] [Accepted: 11/15/2019] [Indexed: 12/30/2022]
Abstract
OBJECTIVE The aim of our study is to develop amine-free photoinitiating systems (PISs) for the polymerization of representative dental methacrylate resins under blue light irradiation. PISs based on camphorquinone (CQ)/sulfinate and CQ/sulfonate, eventually in combination with an iodonium salt, are proposed and compared to the well-established CQ/amine system. The polymerization performances of thick (1.4 mm) samples of different methacrylate blends upon exposure to a commercial blue LED centered at 477 nm under air are described. Finally, the performances of the new developed PISs are evaluated for dental composites application. METHODS FTIR is used to monitor the photopolymerization profiles. ESR spectroscopy and electrochemical experiments are used to identify the radicals generated. Mechanical properties measurements and color stability measurements are carried out to determine the key properties of the dental composites prepared. RESULTS AND SIGNIFICIANCE The performances of the new proposed PISs for the photopolymerization of thick (1.4 mm) samples of methacrylate upon exposure to a blue dental LED under air are excellent. Similar or better performances and bleaching properties are obtained with the new proposed amine-free systems compared to those reached with the CQ/amine reference system. Dental composites with excellent mechanical properties and exceptional color stability are obtained. The involved chemical mechanisms for the initiation step were also established.
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Affiliation(s)
- Julie Kirschner
- Institut de Science des Matériaux de Mulhouse IS2M, UMR CNRS 7361, UHA, 15 Rue Jean Starcky, 68057 Mulhouse Cedex, France
| | | | - Mariem Bouzrati-Zerelli
- Institut de Science des Matériaux de Mulhouse IS2M, UMR CNRS 7361, UHA, 15 Rue Jean Starcky, 68057 Mulhouse Cedex, France
| | - Jean-Michel Becht
- Institut de Science des Matériaux de Mulhouse IS2M, UMR CNRS 7361, UHA, 15 Rue Jean Starcky, 68057 Mulhouse Cedex, France
| | | | - Jacques Lalevée
- Institut de Science des Matériaux de Mulhouse IS2M, UMR CNRS 7361, UHA, 15 Rue Jean Starcky, 68057 Mulhouse Cedex, France.
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Fronza BM, Lewis S, Shah PK, Barros MD, Giannini M, Stansbury JW. Modification of filler surface treatment of composite resins using alternative silanes and functional nanogels. Dent Mater 2019; 35:928-936. [PMID: 31003760 DOI: 10.1016/j.dental.2019.03.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 03/16/2019] [Accepted: 03/18/2019] [Indexed: 11/29/2022]
Abstract
OBJECTIVES This study probes how modifiedapproaches for filler surface treatment in dental composites based on alternative silanes and functional nanogel additives affects physicochemical properties of these materials with a focus on polymerization stress development. METHODS Nanogels were synthesized from isobornyl methacrylate, ethoxylated bisphenol-A dimethacrylate and isocyanatoethyl methacrylate followed by partial further reaction with 2-hydroxyethyl methacrylate to provide both isocyanate and methacrylate functionalization. A barium glass filler (˜1 μm particle size) was treated with either γ-methacryloxypropyltrimethoxysilane (MPS), N-methylaminopropyltrimethoxy (MAP) or N-allylaminopropyltrimethoxy (AAP) silanes. The reactive nanogels were then covalently attached to the aminosilane-treated fillers. Surface treatment was characterized by thermogravimetric analysis (TGA) and diffuse reflectance infrared spectroscopy (DR-IR). Composites were formulated with 60 wt% of the various functionalized fillers and the materials were evaluated for polymerization kinetics, polymerization stress (PS), volumetric shrinkage, mechanical properties and photorheology. Data were evaluated by one-way ANOVA and Tukey's test at 5% significance level. RESULTS Filler surface treatments were confirmed by TGA and DR-IR analyses. Nanogel-functionalized fillers significantly reduced PS up to 20%, while the degree of conversion and elastic modulus were not compromised. Similar storage modulus development during polymerization was observed among materials by photorheology although the rate of polymerization was significantly increased for nanogel-based treatments. A significant decrease in flexural strength was observed for amino functional silane groups; however, there was no statistical difference in strength for the MPS control group compared with the nanogel-modified composites. SIGNIFICANCE Filler surface treatment modified with a reactive nanogel enables significant PS reduction, without compromise to degree of conversion or mechanical properties of dental composites.
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Affiliation(s)
- Bruna Marin Fronza
- Restorative Dentistry Department, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
| | - Steven Lewis
- Craniofacial Biology Department, University of Colorado, Aurora, CO, United States.
| | - Parag K Shah
- Chemical and Biological Engineering, University of Colorado, Boulder, CO, United States.
| | - Matthew D Barros
- Craniofacial Biology Department, University of Colorado, Aurora, CO, United States.
| | - Marcelo Giannini
- Restorative Dentistry Department, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
| | - Jeffrey W Stansbury
- Craniofacial Biology Department, University of Colorado, Aurora, CO, United States; Chemical and Biological Engineering, University of Colorado, Boulder, CO, United States.
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Kimber I. The activity of methacrylate esters in skin sensitisation test methods: A review. Regul Toxicol Pharmacol 2019; 104:14-20. [PMID: 30826317 DOI: 10.1016/j.yrtph.2019.02.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 02/19/2019] [Accepted: 02/22/2019] [Indexed: 10/27/2022]
Abstract
Skin sensitisation associated with allergic contact dermatitis is an important occupational and environmental disease. The identification of skin sensitisation hazards was traditionally performed using animal tests; originally guinea pig assays and subsequently the murine local lymph node assay (LLNA). More recently there has, for a variety of reasons, been an increased interest in, and requirement for, non-animal assays. There are now available both validated in vitro assays and a variety of approaches based on consideration of quantitative structure-activity relationships (QSAR). With the increased availability and use of non-animal alternatives for skin sensitisation testing there is a continuing need to monitor the performance of these approaches using series of chemicals that do not normally form part of validation exercises. Here we report studies conducted with 11 methacrylate esters and methacrylic acid in which results obtained with 3 validated in vitro tests for which there are OECD guidelines (the Direct Peptide Reactivity Assay, DPRA; ARE-Nrf2 luciferase test methods, and - with some chemicals - a dendritic cell activation test, the myeloid U937 Skin Sensitisation test [U-SENS] assay) have been compared with QSAR approaches (DEREK and TIMES-SS), and with LLNA and guinea pig maximisation test (GPMT) data. The conclusions drawn from these data are that - with this series of chemicals at least - there is a strong correlation between the results of animal tests and the in vitro assays considered, but not with either DEREK or TIMES-SS.
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Affiliation(s)
- Ian Kimber
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK.
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Alifui-Segbaya F, Bowman J, White AR, Varma S, Lieschke GJ, George R. Toxicological assessment of additively manufactured methacrylates for medical devices in dentistry. Acta Biomater 2018; 78:64-77. [PMID: 30099197 DOI: 10.1016/j.actbio.2018.08.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 06/28/2018] [Accepted: 08/07/2018] [Indexed: 12/11/2022]
Abstract
The paucity of information on the biological risks of photopolymers in additive manufacturing is a major challenge for the uptake of the technology in the construction of medical devices in dentistry. In this paper, the biocompatibility of methacrylates for denture bases, splints, retainers and surgical guides were evaluated using the innovative zebrafish embryo model, which is providing a high potential for toxicity profiling of photopolymers and has high genetic similarity to humans. Toxicological data obtained confirmed gradations of toxicity influenced by ethanol treatment, exposure scenarios and extraction vehicles. In direct exposure tests, juvenile fish exposed to non-treated methacrylates in ultrapure water showed accelerated toxicity endpoints compared to fish in transparent E3 medium. Similarly, toxic extracts induced mostly acute responses (embryonic mortality) in contrast to cumulative chronic (sublethal and teratogenic effects) in direct exposure. Methacrylates composed of >60% Ethoxylated bisphenol A dimethacrylate produced a relatively lower conversion rate in FTIR spectroscopy, but were safe in zebrafish bioassays after ethanol treatment. The study affirms that biocompatibility was influenced primarily by physico-chemical characteristics of the materials, which subsequently influenced their residual monomer content before and after immersion in ethanol. Given the precautionary implications of the study, we propose a 3-tiered approach i.e. using approved materials, apposite manufacturing parameters and post-processing techniques that together guarantee optimal results for medical devices. STATEMENT OF SIGNIFICANCE This study is timely and relevant since there is limited published literature that precisely describes the toxicological properties of additively manufactured methacrylates despite their increased popularity for medical devices. While it is generally accepted that the zebrafish excels as a model system for developmental toxicity, a further examination of its utility in this study using different protocols provides basis for its consideration and adoption at a crucial time when there is a lack of consensus regarding the most suited biological assessment methods for medical devices.
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Affiliation(s)
- Frank Alifui-Segbaya
- School of Dentistry and Oral Health, Griffith Health, Gold Coast Campus, Griffith University, QLD 4222, Australia.
| | - Jasper Bowman
- School of Environment and Science, Griffith Sciences, Nathan Campus, Griffith University, QLD 4111, Australia.
| | - Alan R White
- School of Environment and Science, Griffith Sciences, Nathan Campus, Griffith University, QLD 4111, Australia.
| | - Sony Varma
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria 3800, Australia.
| | - Graham J Lieschke
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria 3800, Australia.
| | - Roy George
- School of Dentistry and Oral Health, Griffith Health, Griffith University, Australia.
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13
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Albertini RJ. The lower alkyl methacrylates: Genotoxic profile of non-carcinogenic compounds. Regul Toxicol Pharmacol 2017; 84:77-93. [PMID: 28087335 DOI: 10.1016/j.yrtph.2017.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Revised: 01/05/2017] [Accepted: 01/09/2017] [Indexed: 12/22/2022]
Abstract
All of the lower alkyl methacrylates are high production chemicals with potential for human exposure. The genotoxicity of seven mono-functional alkyl esters of methacrylic acid, i.e. methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, n-, i- and t-butyl methacrylate and 2 ethyl hexyl methacrylate, as well as methacrylic acid itself, the acyl component common to all, is reviewed and compared with the lack of carcinogenicity of methyl methacrylate, the representative member of the series so evaluated. Also reviewed are the similarity of structure, chemical and biological reactivity, metabolism and common metabolic products of this group of compounds which allows a category approach for assessing genotoxicity. As a class, the lower alkyl methacrylates are universally negative for gene mutations in prokaryotes but do exhibit high dose clastogenicity in mammalian cells in vitro. There is no convincing evidence that these compounds induce genotoxic effects in vivo in either sub-mammalian or mammalian species. This dichotomy of effects can be explained by the potential genotoxic intermediates generated in vitro. This genotoxic profile of the lower alkyl methacrylates is consistent with the lack of carcinogenicity of methyl methacrylate.
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14
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Martim GC, Pfeifer CS, Girotto EM. Novel urethane-based polymer for dental applications with decreased monomer leaching. Mater Sci Eng C Mater Biol Appl 2016; 72:192-201. [PMID: 28024577 DOI: 10.1016/j.msec.2016.11.050] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 10/18/2016] [Accepted: 11/13/2016] [Indexed: 11/15/2022]
Abstract
The aim of this study was to synthesize and characterize new multifunctional-urethane-methacrylate monomers to be used as the organic matrix in restorative dental composites, and evaluate the main physical-chemical properties of the resulting material. Bis-GMA (bisphenol-A-diglycidylmethacrylate) and GDMA (glycerol dimethacrylate) were modified by reacting the hydroxyl groups with isocyanate groups of urethane-methacrylate precursors to result in the new monomeric systems U-(bis-GMA)-Mod and U-(GDMA)-Mod, U=Urethane and Mod=Modified. The modifications were characterized by FTIR and 1H NMR. The final monomeric synthesized system was used to prepare dental resins and composites. The physical-chemical properties were evaluated and compared with those of bis-GMA composites with varying filler contents or unfilled resins. U-(bis-GMA)-Mod and U-(GDMA)-Mod can be used to prepare dental restorative composites, with some foreseeable advantages compared with bis-GMA composites. One significant advantage is that these composites have the potential to be less toxic, once they presented a reduction of 50% in leaching of unreacted monomers extracted by solvent.
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Affiliation(s)
- Gedalias C Martim
- Materials Chemistry and Sensors Laboratories, Department of Chemistry, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900 Maringá, Paraná, Brazil
| | - Carmem S Pfeifer
- Biomaterials and Biomechanics, Oregon Health and Science University, 611 SW Campus Dr, Portland, OR 97239, USA
| | - Emerson M Girotto
- Materials Chemistry and Sensors Laboratories, Department of Chemistry, Universidade Estadual de Maringá, Av. Colombo 5790, 87020-900 Maringá, Paraná, Brazil.
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15
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Bouzrati-Zerelli M, Maier M, Dietlin C, Fabrice MS, Fouassier JP, Klee JE, Lalevée J. A novel photoinitiating system producing germyl radicals for the polymerization of representative methacrylate resins: Camphorquinone/R3GeH/iodonium salt. Dent Mater 2016; 32:1226-34. [PMID: 27567540 DOI: 10.1016/j.dental.2016.07.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Revised: 06/30/2016] [Accepted: 07/16/2016] [Indexed: 11/22/2022]
Abstract
OBJECTIVES The aim of our study is to find an amine free photoinitiating system (PIS) for the polymerization of representative dental methacrylate resins. A photoinitiating system (PIS) based on camphorquinone (CQ)/triphenylgermanium hydride/diphenyl iodonium hexafluorophosphate is proposed and compared to the conventional CQ/amine couple. The polymerization monitoring of thin (∼20μm) and thick (1.4mm) samples of a bisphenol A-glycidyl methacrylate (Bis-GMA)/triethyleneglycol dimethacrylate (TEGDMA) blend (70%/30% w/w) and of a urethane dimethacrylate (UDMA) upon exposure to a commercial blue LED centered at 477nm under air or in laminate is described. Finally, the impact of the photoinitiating system composition on the final polymer color is evaluated in detail. METHODS FTIR and DSC experiments are used to record the photopolymerization profiles. ESR spectrometry and steady state photolysis are used to detect the produced radicals. Color measurements are carried out to determine the key parameters in the bleaching of the different dental formulations. RESULTS The efficiency of the newly proposed PISs for the photopolymerization of BisGMA/TEGDMA and UDMA for thin (20μm) or for thick (1.4mm) samples upon exposure to a dental blue LED under air is excellent. It is noticeably higher than that of the CQ/amine reference couple. Excellent bleaching properties are also observed under irradiation in presence of the new PISs. A good correlation is found between the sample bleaching and the amount of Ph3GeH in the formulation. The excited state processes could be established. The overall chemical mechanisms for the initiation step were also clarified.
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16
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Pacheco KA. Allergy to Surgical Implants. J Allergy Clin Immunol Pract. 2015;3:683-695. [PMID: 26362550 DOI: 10.1016/j.jaip.2015.07.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 07/06/2015] [Accepted: 07/07/2015] [Indexed: 01/26/2023]
Abstract
Surgical implants have a wide array of therapeutic uses, most commonly in joint replacements, but also in repair of pes excavatum and spinal disorders, in cardiac devices (stents, patches, pacers, valves), in gynecological implants, and in dentistry. Many of the metals used are immunologically active, as are the methacrylates and epoxies used in conjunction with several of these devices. Allergic responses to surgical components can present atypically as failure of the device, with nonspecific symptoms of localized pain, swelling, warmth, loosening, instability, itching, or burning; localized rash is infrequent. Identification of the specific metal and cement components used in a particular implant can be difficult, but is crucial to guide testing and interpretation of results. Nickel, cobalt, and chromium remain the most common metals implicated in implant failure due to metal sensitization; methacrylate-based cements are also important contributors. This review will provide a guide on how to assess and interpret the clinical history, identify the components used in surgery, test for sensitization, and provide advice on possible solutions. Data on the pathways of metal-induced immune stimulation are included. In this setting, the allergist, the dermatologist, or both have the potential to significantly improve surgical outcomes and patient care.
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17
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Genari B, Leitune VCB, Jornada DS, Camassola M, Pohlmann AR, Guterres SS, Samuel SMW, Collares FM. Effect of indomethacin-loaded nanocapsules incorporation in a dentin adhesive resin. Clin Oral Investig 2016; 21:437-446. [PMID: 27068412 DOI: 10.1007/s00784-016-1810-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 03/23/2016] [Indexed: 12/01/2022]
Abstract
OBJECTIVES The aim of this study was to produce indomethacin-loaded nanocapsules (IndOH-NCs) and evaluate the influence of their incorporation into an adhesive resin. MATERIALS AND METHODS Indomethacin was encapsulated by the deposition of preformed polymer. IndOH-NCs were characterized by laser diffractometry, Fourier transformed infrared spectrometry, transmission electron microscopy (TEM), scanning electron microscopy, high-performance liquid chromatography (HPLC), and MTT assay. Nanocapsules (NCs) were incorporated into an adhesive in concentrations of 1, 2, 5, and 10 %. The addition was visualized by TEM and drug release was evaluated by HPLC until 120 h of immersion in simulated body fluid (SBF). Drug diffusion through dentin was tested using a Franz diffusion cell apparatus and quantified by HPLC. The degree of conversion (DC), softening in ethanol, and microtensile bond strength (μTBS) were evaluated to determine whether the nanocapsules influenced the adhesive. Data were analyzed using one-way ANOVA and Tukey's post hoc test for DC, softening in ethanol, μTBS, and cytotoxicity, and paired t test for comparison between the initial and final Knoop microhardness. RESULTS IndOH-NCs, with a spherical shape and a mean diameter of 165 nm, were incorporated into an adhesive. Indomethacin content was 7 mg drug/g powder. IndOH-NCs maintained high cell viability. At 120 h, an amount of 13.83 % of indomethacin was released, and after 7 days, 7.07 % of this drug was diffused through dentin for an adhesive containing 10 % of nanocapsules. No alteration in the DC, softening in ethanol, and μTBS resulted from NC addition. CONCLUSIONS IndOH-NCs may be incorporated into adhesive systems, without compromising properties, to add an anti-inflammatory drug controlled release for restorative procedures in deep cavities. CLINICAL SIGNIFICANCE Here is the first step toward the goal of providing agents to act at an inflammatory process of pulp tissue through dental adhesives via encapsulation of drug.
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Affiliation(s)
- Bruna Genari
- Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, Porto Alegre, RS, 2492, Brazil
| | - Vicente Castelo Branco Leitune
- Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, Porto Alegre, RS, 2492, Brazil
| | | | - Melissa Camassola
- Laboratory of stem cells and tissue engineering, Universidade Luterana do Brazil, Porto Alegre, RS, Brazil
| | - Adriana Raffin Pohlmann
- Pharmaceutical Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.,Institute of Chemistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil
| | | | - Susana Maria Werner Samuel
- Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, Porto Alegre, RS, 2492, Brazil
| | - Fabrício Mezzomo Collares
- Dental Materials Laboratory, School of Dentistry, Federal University of Rio Grande do Sul, Ramiro Barcelos Street, Porto Alegre, RS, 2492, Brazil.
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Shirinzad M, Rezaei-Soufi L, Mirtorabi MS, Vahdatinia F. Effect of Accelerated Artificial Aging on Translucency of Methacrylate and Silorane-Based Composite Resins. J Dent (Tehran) 2016; 13:92-100. [PMID: 27928237 PMCID: PMC5139936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2015] [Accepted: 01/02/2016] [Indexed: 06/06/2023]
Abstract
OBJECTIVES Composite restorations must have tooth-like optical properties namely color and translucency and maintain them for a long time. This study aimed to compare the effect of accelerated artificial aging (AAA) on the translucency of three methacrylate-based composites (Filtek Z250, Filtek Z250XT and Filtek Z350XT) and one silorane-based composite resin (Filtek P90). MATERIALS AND METHODS For this in vitro study, 56 composite discs were fabricated (n=14 for each group). Using scanning spectrophotometer, CIE L*a*b* parameters and translucency of each specimen were measured at 24 hours and after AAA for 384 hours. Data were analyzed using one-way ANOVA, Tukey's test and paired t-test at P=0.05 level of significance. RESULTS The mean (±standard deviation) translucency parameter for Filtek Z250, Filtek Z250XT, Filtek Z350XT and Filtek P90 was 5.67±0.64, 4.59±0.77, 7.87±0.82 and 4.21±0.71 before AAA and 4.25±0.615, 3.53±0.73, 5.94±0.57 and 4.12±0.54 after AAA, respectively. After aging, the translucency of methacrylate-based composites decreased significantly (P<0.05). However, the translucency of Filtek P90 did not change significantly (P>0.05). CONCLUSIONS The AAA significantly decreased the translucency of methacrylate-based composites (Filtek Z250, Filtek Z250XT and Filtek Z350XT) but no change occurred in the translucency of Filtek P90 silorane-based composite.
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Affiliation(s)
- Mehdi Shirinzad
- Associate Professor, Department of Operative Dentistry, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Loghman Rezaei-Soufi
- Associate Professor, Dental Research Center, Department of Operative Dentistry, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran
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