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Vallittu PK, Posti JP, Piitulainen JM, Serlo W, Määttä JA, Heino TJ, Pagliari S, Syrjänen SM, Forte G. Biomaterial and implant induced ossification: in vitro and in vivo findings. J Tissue Eng Regen Med 2020; 14:1157-1168. [PMID: 32415757 PMCID: PMC7496445 DOI: 10.1002/term.3056] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/30/2020] [Accepted: 05/04/2020] [Indexed: 12/12/2022]
Abstract
Material-induced ossification is suggested as a suitable approach to heal large bone defects. Fiber-reinforced composite-bioactive glasses (FRC-BGs) display properties that could enhance the ossification of calvarial defects. Here, we analyzed the healing processes of a FRC-BG implant in vivo from the perspective of material-induced ossification. Histological analysis of the implant, which was removed 5 months after insertion, showed the formation of viable, noninflammatory mesenchymal tissue with newly-formed mineralized woven bone, as well as nonmineralized connective tissue with capillaries and larger blood vessels. The presence of osteocytes was detected within the newly generated bone matrix. To expand our understanding on the osteogenic properties of FRC-BG, we cultured human adipose tissue-derived mesenchymal stromal cells (AD-MSCs) in the presence of two different BGs (45S5 and S53P4) and Al2 O3 control. AD-MSCs grew and proliferated on all the scaffolds tested, as well as secreted abundant extracellular matrix, when osteogenic differentiation was appropriately stimulated. 45S5 and S53P4 induced enhanced expression of COL2A1, COL10A1, COL5A1 collagen subunits, and pro-osteogenic genes BMP2 and BMP4. The concomitant downregulation of BMP3 was also detected. Our findings show that FRC-BG can support the vascularization of the implant and the formation of abundant connective tissue in vivo. Specifically, BG 45S5 and BG S53P4 are suited to evoke the osteogenic potential of host mesenchymal stromal cells. In conclusion, FRC-BG implant demonstrated material-induced ossification both in vitro and in vivo.
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Affiliation(s)
- Pekka K. Vallittu
- Department of Biomaterials ScienceInstitute of Dentistry, University of Turku and City of Turku, Welfare DivisionTurkuFinland
| | - Jussi P. Posti
- Division of Clinical Neurosciences, Department of Neurosurgery, Turku Brain Injury CentreTurku University Hospital and University of TurkuTurkuFinland
| | - Jaakko M. Piitulainen
- Division of Surgery and Cancer Diseases, Department of Otorhinolaryngology ‐ Head and Neck Surgery, Turku University HospitalTurku Finland and University of TurkuTurkuFinland
| | - Willy Serlo
- PEDEGO Research Unit, University of Oulu, Oulu, Finland and Department of Children and AdolescentsOulu University HospitalOuluFinland
| | | | | | - Stefania Pagliari
- International Clinical Research Center of St. Anne's University Hospital BrnoBrnoCzech Republic
| | - Stina M. Syrjänen
- Department of Oral Pathology and Radiology, Institute of DentistryUniversity of TurkuTurkuFinland
| | - Giancarlo Forte
- International Clinical Research Center of St. Anne's University Hospital BrnoBrnoCzech Republic
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Välimaa S, Perea-Lowery L, Smått JH, Peltonen J, Budde T, Vallittu PK. Grit blasted aggregates of hydroxyl apatite functionalized calcium carbonate in occluding dentinal tubules. Heliyon 2019; 4:e01049. [PMID: 30603691 PMCID: PMC6307103 DOI: 10.1016/j.heliyon.2018.e01049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 09/03/2018] [Accepted: 12/11/2018] [Indexed: 11/26/2022] Open
Abstract
Objectives This study aimed to investigate the effects of using hydroxyl apatite functionalized calcium carbonate (FCC) particles on occluding dentinal tubules. Methods Dentine specimens extracted from eighteen human molars with exposed dentinal tubules were divided into three groups (n = 6/group): a) Cut surface with smear layer; b) EDTA (smear layer removed with 17% EDTA for 1 min); and c) Grit blasted functionalized calcium carbonate (FCC) with and air pressure of 280 kPa. Microscopic dentinal tubule occlusion, tubule diameter and tubule area were evaluated using scanning electron microscopy (SEM) before and after grit blasting. Biomineralization of specimens was carried out in a simulated body fluid (SBF). Elemental analysis of occluding materials was carried out using energy-dispersive X-ray spectroscopy (EDX). X-ray diffraction (XRD) analysis was performed to demonstrate the crystal structure of the biomineralized layer on dentine. Results FCC particles showed penetration into the dentinal tubules by breakage of their original particle shape and size. EDTA treated surface had higher number and larger size tubules than those with smear layer or grit blasted (p < 0.005). SEM-EDX analysis revealed mineral precipitation of calcium phosphate on the SBF immersed dentin specimens. XRD analysis showed typical crystal structure of hydroxyl apatite for the biomineralized surface layer on dentine. Conclusions Grit blasted FCC particles initially occluded effectively the opened dentinal tubules and biomineralization occurred in tubules primarily occluded by the FCC particles. However, in the optimal in vitro conditions in SBF, no difference between biomineralization was found between the grit blasted surface and the control surface. Clinical significance Several materials and methods have been established for treatment of dentinal hypersensitivity although a golden standard treatment has not been discovered. Grit blasted functionalized calcium carbonate has a potential to occlude and remineralize exposed dentinal tubules. This could offer a more biological approach on treatment of dentin hypersensitivity.
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Affiliation(s)
- S Välimaa
- Department of Biomaterials Science and Turku Clinical Biomaterials Centre - TCBC, Institute of Dentistry, University of Turku, Finland
| | - L Perea-Lowery
- Department of Biomaterials Science and Turku Clinical Biomaterials Centre - TCBC, Institute of Dentistry, University of Turku, Finland
| | - J-H Smått
- Laboratory of Physical Chemistry, Faculty of Science and Engineering and Center for Functional Materials, Åbo Akademi University, Finland
| | - J Peltonen
- Laboratory of Physical Chemistry, Faculty of Science and Engineering and Center for Functional Materials, Åbo Akademi University, Finland
| | - T Budde
- Omya International AG, Oftringen, Switzerland
| | - P K Vallittu
- Department of Biomaterials Science and Turku Clinical Biomaterials Centre - TCBC, Institute of Dentistry, University of Turku, Finland.,City of Turku, Welfare Division, Finland
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HOIKKALA NPJ, WANG X, HUPA L, SMÅTT JH, PELTONEN J, VALLITTU PK. Dissolution and mineralization characterization of bioactive glass ceramic containing endodontic sealer Guttaflow Bioseal. Dent Mater J 2018; 37:988-994. [DOI: 10.4012/dmj.2017-224] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Niko-Pekka Johannes HOIKKALA
- Department of Biomaterials Science and Turku Clinical Biomaterials Center–TCBC, Institute of Dentistry, University of Turku
| | - Xiaoju WANG
- Johan Gadolin Process Chemistry Center, Åbo Akademi University
| | - Leena HUPA
- Johan Gadolin Process Chemistry Center, Åbo Akademi University
| | | | - Jouko PELTONEN
- Laboratory of Physical Chemistry, Åbo Akademi University
| | - Pekka K. VALLITTU
- Department of Biomaterials Science and Turku Clinical Biomaterials Center–TCBC, Institute of Dentistry, University of Turku
- City of Turku Welfare Division, Oral Health Care
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Das I, De G, Hupa L, Vallittu PK. Porous SiO2 nanofiber grafted novel bioactive glass–ceramic coating: A structural scaffold for uniform apatite precipitation and oriented cell proliferation on inert implant. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2016; 62:206-14. [DOI: 10.1016/j.msec.2016.01.053] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 01/04/2016] [Accepted: 01/20/2016] [Indexed: 10/22/2022]
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Ostrowski N, Lee B, Hong D, Enick PN, Roy A, Kumta PN. Synthesis, Osteoblast, and Osteoclast Viability of Amorphous and Crystalline Tri-Magnesium Phosphate. ACS Biomater Sci Eng 2014; 1:52-63. [DOI: 10.1021/ab500073c] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nicole Ostrowski
- Swanson School of Engineering, Department of Bioengineering, University of Pittsburgh, 3700 O’Hara
Street, Pittsburgh, Pennsylvania 15261, United States
| | - Boeun Lee
- Swanson School of Engineering, Department of Bioengineering, University of Pittsburgh, 3700 O’Hara
Street, Pittsburgh, Pennsylvania 15261, United States
| | - Daeho Hong
- Swanson School of Engineering, Department of Bioengineering, University of Pittsburgh, 3700 O’Hara
Street, Pittsburgh, Pennsylvania 15261, United States
| | - P. Nathan Enick
- Swanson School of Engineering, Department of Bioengineering, University of Pittsburgh, 3700 O’Hara
Street, Pittsburgh, Pennsylvania 15261, United States
| | - Abhijit Roy
- Swanson School of Engineering, Department of Bioengineering, University of Pittsburgh, 3700 O’Hara
Street, Pittsburgh, Pennsylvania 15261, United States
| | - Prashant N. Kumta
- Swanson School of Engineering, Department of Bioengineering, University of Pittsburgh, 3700 O’Hara
Street, Pittsburgh, Pennsylvania 15261, United States
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Campion CR, Ball SL, Clarke DL, Hing KA. Microstructure and chemistry affects apatite nucleation on calcium phosphate bone graft substitutes. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2013; 24:597-610. [PMID: 23242766 DOI: 10.1007/s10856-012-4833-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 11/30/2012] [Indexed: 06/01/2023]
Abstract
The bioactivity of calcium phosphate bone grafts of varying chemistry and strut-porosity was compared by determining the rate of formation of hydroxycarbonate apatite crystals on the material surface after being soaked in simulated body fluid for up to 30 days. Three groups of silicate-substituted hydroxyapatite material were tested, with each group comprising a different quantity of strut-porosity (23, 32, and 46 % volume). A commercially available porous β-tricalcium phosphate bone graft substitute was tested for comparison. Results indicate that strut-porosity of a material affects the potential for formation of a precursor to bone-like apatite and further confirms previous findings that β-tricalcium phosphate is less bioactive than hydroxyapatite.
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Affiliation(s)
- Charlie R Campion
- Department of Materials, School of Engineering and Materials, Queen Mary, University of London, London, UK
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Nganga S, Zhang D, Moritz N, Vallittu PK, Hupa L. Multi-layer porous fiber-reinforced composites for implants: in vitro calcium phosphate formation in the presence of bioactive glass. Dent Mater 2012; 28:1134-45. [PMID: 22925703 DOI: 10.1016/j.dental.2012.08.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Accepted: 08/09/2012] [Indexed: 10/28/2022]
Abstract
OBJECTIVES Glass-fiber-reinforced composites (FRCs), based on bifunctional methacrylate resin, have recently shown their potential for use as durable cranioplasty, orthopedic and oral implants. In this study we suggest a multi-component sandwich implant structure with (i) outer layers out of porous FRC, which interface the cortical bone, and (ii) inner layers encompassing bioactive glass granules, which interface with the cancellous bone. METHODS The capability of Bioglass(®) 45S5 granules (100-250μm) to induce calcium phosphate formation on the surface of the FRC was explored by immersing the porous FRC-Bioglass laminates in simulated body fluid (SBF) for up to 28d. RESULTS In both static (agitated) and dynamic conditions, bioactive glass granules induced precipitation of calcium phosphate at the laminate surfaces as confirmed by scanning electron microscopy. SIGNIFICANCE The proposed dynamic flow system is useful for the in vitro simulation of bone-like apatite formation on various new porous implant designs containing bioactive glass and implant material degradation.
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Affiliation(s)
- Sara Nganga
- Department of Biomaterials Science, University of Turku, Turku, Finland.
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Mori H, Endo T. Amino-Acid-Based Block Copolymers by RAFT Polymerization. Macromol Rapid Commun 2012; 33:1090-107. [DOI: 10.1002/marc.201100887] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 02/19/2012] [Indexed: 12/21/2022]
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Rekola J, Lassila LVJ, Hirvonen J, Lahdenperä M, Grenman R, Aho AJ, Vallittu PK. Effects of heat treatment of wood on hydroxylapatite type mineral precipitation and biomechanical properties in vitro. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2010; 21:2345-2354. [PMID: 20464458 DOI: 10.1007/s10856-010-4087-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 04/26/2010] [Indexed: 05/29/2023]
Abstract
Wood is a natural fiber reinforced composite. It structurally resembles bone tissue to some extent. Specially heat-treated birch wood has been used as a model material for further development of synthetic fiber reinforced composites (FRC) for medical and dental use. In previous studies it has been shown, that heat treatment has a positive effect on the osteoconductivity of an implanted wood. In this study the effects of two different heat treatment temperatures (140 and 200 degrees C) on wood were studied in vitro. Untreated wood was used as a control material. Heat treatment induced biomechanical changes were studied with flexural and compressive tests on dry birch wood as well as on wood after 63 days of simulated body fluid (SBF) immersion. Dimensional changes, SBF sorption and hydroxylapatite type mineral formation were also assessed. The results showed that SBF immersion decreases the biomechanical performance of wood and that the heat treatment diminishes the effect of SBF immersion on biomechanical properties. With scanning electron microscopy and energy dispersive X-ray analysis it was shown that hydroxylapatite type mineral precipitation formed on the 200 degrees C heat-treated wood. An increased weight gain of the same material during SBF immersion supported this finding. The results of this study give more detailed insight of the biologically relevant changes that heat treatment induces in wood material. Furthermore the findings in this study are in line with previous in vivo studies.
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Affiliation(s)
- J Rekola
- Department of Biomaterials Science, University of Turku, Turku, Finland.
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Lv Q, Nair L, Laurencin CT. Fabrication, characterization, and in vitro evaluation of poly(lactic acid glycolic acid)/nano-hydroxyapatite composite microsphere-based scaffolds for bone tissue engineering in rotating bioreactors. J Biomed Mater Res A 2010; 91:679-91. [PMID: 19030184 DOI: 10.1002/jbm.a.32302] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Dynamic flow culture bioreactor systems have been shown to enhance in vitro bone tissue formation by facilitating mass transfer and providing mechanical stimulation. Our laboratory has developed a biodegradable poly (lactic acid glycolic acid) (PLAGA) mixed scaffold consisting of lighter-than-water (LTW) and heavier-than-water (HTW) microspheres as potential matrices for engineering tissue using a high aspect ratio vessel (HARV) rotating bioreactor system. We have demonstrated enhanced osteoblast differentiation and mineralization on PLAGA scaffolds in the HARV rotating bioreactor system when compared with static culture. The objective of the present study is to improve the mechanical properties and bioactivity of polymeric scaffolds by designing LTW polymer/ceramic composite scaffolds suitable for dynamic culture using a HARV bioreactor. We employed a microsphere sintering method to fabricate three-dimensional PLAGA/nano-hydroxyapatite (n-HA) mixed scaffolds composed of LTW and HTW composite microspheres. The mechanical properties, pore size and porosity of the composite scaffolds were controlled by varying parameters, such as sintering temperature, sintering time, and PLAGA/n-HA ratio. The PLAGA/n-HA (4:1) scaffold sintered at 90 degrees C for 3 h demonstrated the highest mechanical properties and an appropriate pore structure for bone tissue engineering applications. Furthermore, evaluation human mesenchymal stem cells (HMSCs) response to PLAGA/n-HA scaffolds was performed. HMSCs on PLAGA/n-HA scaffolds demonstrated enhanced proliferation, differentiation, and mineralization when compared with those on PLAGA scaffolds. Therefore, PLAGA/n-HA mixed scaffolds are promising candidates for HARV bioreactor-based bone tissue engineering applications.
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Affiliation(s)
- Qing Lv
- Department of Chemical Engineering, University of Virginia, Charlottesville, Virginia, USA
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Lin NJ, Lin-Gibson S. Osteoblast response to dimethacrylate composites varying in composition, conversion and roughness using a combinatorial approach. Biomaterials 2009; 30:4480-7. [PMID: 19520423 DOI: 10.1016/j.biomaterials.2009.05.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2009] [Accepted: 05/10/2009] [Indexed: 10/20/2022]
Abstract
Dimethacrylate polymers and composites are seeing increased usage in orthopedics. As these applications require the material to integrate with the surrounding tissues, direct contact cytotoxicity assays should be used to assess the biocompatibility. This study utilized a combinatorial testing platform to evaluate the cell response to dimethacrylate composites with a variety of properties on a single sample. MC3T3-E1 pre-osteoblasts were cultured directly on composites with varying filler content, filler type, degree of conversion (DC), and surface topography. Cell viability, density, and area depended on an interplay of the material properties, with low DC causing a reduction in cell area but having minimal effect on cell viability, high filler content causing an increase in cell density, and filler content/type altering the surface roughness as a function of DC. The combinatorial testing platform successfully quantified the effects of numerous material properties on several aspects of the osteoblast response.
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Affiliation(s)
- Nancy J Lin
- Polymers Division, National Institute of Standards and Technology, 100 Bureau Drive, MS 8543, Gaithersburg, MD 20899-8543, USA.
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The effect of heat treatment of wood on osteoconductivity. Acta Biomater 2009; 5:1596-604. [PMID: 19231305 DOI: 10.1016/j.actbio.2009.01.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2008] [Revised: 12/09/2008] [Accepted: 01/13/2009] [Indexed: 11/22/2022]
Abstract
Wood is a natural porous fibre composite, which has some structural similarities to bone. Recently, it has been used as a modelling material in developing synthetic fibre-reinforced composite to be used as load-bearing non-metallic artificial bone material. In this study, the behaviour of wood implanted into bone was studied in vivo in the femur bone of the rabbit. Wood was pre-treated by heat, which altered its chemical composition and structure, as well as the biomechanical properties. In the heat treatment, wood's dimensional stability is enhanced, equilibrium moisture content reduces and the biological durability increases. Cone-shaped implants were manufactured from heat-treated (at 200 and 140 degrees C) birch wood (Betula pubescens) and from untreated birch. A total of 62 implants were placed in the distal femur of 50 white New Zealand rabbits. The behaviour of the implants was studied at 4, 8 and 20 weeks with histological and histometrical analysis. Osteoconductive contact line and the presence of fibrous tissue and foreign body reaction were determined. The amount of fibrous tissue diminished with time, and the absence of foreign body reaction was found to be in correlation to the amount of heat treatment. Histologically found contact between the implant and the host bone at the interface was significantly more abundant in the 200 degrees C group (avg. 12.8%) vs. the 140 degrees C (avg. 2.7%) and the untreated groups (avg. 0.6%). It was observed that the heat treatment significantly modified the biological behaviour of the implanted wood. The changes of the wood by heat treatment showed a positive outcome concerning osteoconductivity of the material.
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Abstract
Acrylic bone cements are used to fix joint replacements to bone. The main substance in
acrylic bone cement is biologically inert poly(methylmethacrylate), PMMA. The dense PMMA
polymer structure of cement does not allow bone ingrowth into cement. Therefore, the main focus of
our studies is to modify acrylic bone cement in order to improve its biological properties e.g., by
creating porosity in the cement matrix. The porous structure is in situ created using pore-generating
filler (i.e., 20 wt% of an experimental biodegradable polyamide) that is incorporated in acrylic bone
cement. The aim of this in vitro study was to investigate the biomineralization of acrylic bone cement
modified using an experimental biodegradable polyamide.
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Abstract
Implants with long lasting bioactivity and mechanical sustainability would be of interest in several novel clinical applications. By processing bioactive glass fibers and biodegradable polymers into 3D structures, bone formation ability of glasses and flexibility of polymers can be combined. In order to achieve desired physiological response, reactivity of bioactive glass fibers must be specified. Bundles of fibers within the range of bioactivity were soaked in the simulated body fluid at stationary conditions for several time intervals after which the cross-sectional surfaces of the fibers were studied with SEM-EDXA. The reaction layers and precipitations formed on the fiber surfaces suggest that the fibers react according to three mechanisms depending on the glass composition. Fibers with a high in vitro bioactivity showed the formation of distinct and thick silica –rich and calcium phosphate –rich layers already at one day’s immersion. Fibers of medium bioactivity did not show any clear silica –rich layer but a formation of calcium phosphate precipitations or layers at one day’s immersion. Slow glasses showed sporadic calcium phosphate precipitation only after the longest immersion times. The results indicate that the medium and slow glasses are interesting alternatives for applications where a long term mechanical durability suggested by their slow reactivity in combination with their osteoconductive tendency is desired.
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Väkiparta M, Puska M, Vallittu PK. Residual monomers and degree of conversion of partially bioresorbable fiber-reinforced composite. Acta Biomater 2006; 2:29-37. [PMID: 16701856 DOI: 10.1016/j.actbio.2005.08.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2005] [Revised: 08/23/2005] [Accepted: 08/23/2005] [Indexed: 11/20/2022]
Abstract
The aim of this study was to evaluate the total quantity of residual monomer (bis-phenyl glycidyl dimethacrylate, i.e. Bis-GMA, and triethylene glycol dimethacrylate, i.e. TEGDMA), residual monomer release into water and the degree of monomer conversion (DC%) of glass fiber-reinforced composites (FRC) with a partially bioresorbable polymer matrix. Another aim was to find out whether the curing mode affects the quantity of residual monomer and degree of conversion. Glass fibers were preimpregnated with a bioresorbable poly(hydroxyproline) amide and non-resorbable Bis-GMA-TEGDMA resin system. Specimens were immersed in water for 1, 3 or 7 days (37 degrees C) to determine the quantity of leached residual monomers, or in the solvent tetrahydrofuran for 3 days to determine the total quantity of residual monomers by high performance liquid chromatography. DC% was measured by Fourier transform infrared spectroscopy. The quantity of residual monomer of the specimens decreased when the specimens contained glass fibers, and/or poly(hydroxyproline) amide, and/or when it was post-cured. The majority of the residual monomers were leached out during the first 24 h of immersion in water. The DC% of the specimens increased when post-cured. Also glass fibers in the composite increased the DC% in contrast to Bis-GMA-TEGDMA resin only. In conclusion, use of poly(hydroxyproline) amide as a sizing of the glass fibers in FRC does not increase the quantity of residual monomers. These results suggest that this new kind of partially bioresorbable FRC has potential for biomedical applications.
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Affiliation(s)
- Marju Väkiparta
- Department of Prosthetic Dentistry and Biomaterials Science, Turku Biomaterials Centre, Institute of Dentistry, University of Turku, Itäinen Pitkäkatu 4 B, 20520 Turku, Finland.
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