bluuebunny/crossref_metadata_2025_split huggingface dataset:
Degradation patterns of different adhesives and bonding procedures
Authors: Hashimoto Masanori , Ohno Hiroki , Sano Hidehiko , Kaga Masayuki , Oguchi Haruhisa 
Published: June 2003

AbstractVarious types of resin adhesives and procedures are available in the clinical field, so comprehensive understanding of degradation is required for each material and bonding procedure. The objective of this study was to investigate the bond durability for different adhesives and bonding procedures. Resin–dentin bonded beams were prepared with the use of two adhesives (One‐Up Bond F/self‐etching primer system and One Bond/total‐etch adhesive) and two experimental groups for the bonding procedure (wet and dry bonding of the total‐etch adhesive). Those samples were soaked in water for 24 h(control), 6 and 12 months. After the water immersion, the bond strengths were measured by the microtensile bond test, and subsequently fractography was performed with the use of SEM. Statistically significant reduction of the bond strength (p < 0.05) was apparent after 12 months of water exposure in the range 22–48% of the control. The bonding resin was eluted from the hybrid layer of the self‐etching and the total‐etch adhesives for the wet bonding. Micromorphological alterations were found due to the hydrolysis of collagen fibrils with the total‐etch adhesive for the dry bonding mode. These pathologic alterations were in accord with the bond strength. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 324–330, 2003
Mechanical evaluation of a porous bone graft substitute based on poly(propylene glycol‐co‐fumaric acid)
Authors: Hile David D. , Kirker‐Head Carl , Doherty Stephen A. , Kowaleski Michael P. , McCool John , Wise Donald L. , Trantolo Debra J. 
Published: June 2003

AbstractA porous, resorbable polymer composite based on poly(propylene glycol‐co‐fumaric acid) (PPF) was mechanically evaluated in vitro for use as a bone graft substitute and fracture fixative. The test material created a dynamic system capable of initially providing mechanical integrity to bony voids and a degradative mechanism for ingrowth by native bone. The unsaturated polymer, PPF, was crosslinked in the presence of effervescent agents to yield a porous microstructure upon curing. An in vitro degradation study first assessed the temporal mechanical properties of the test material. This research was followed by an ex vivo study using a long‐bone osteotomy model to characterize the mechanics of fixation. Results showed the initial compressive strength of the cross‐linked PPF system was comparable to cancellous bone. The rate of strength loss was commensurate with the predicted mechanical recovery of healing bone with analogous results in a composite that comprised also 25% (by weight) autograft. Mechanical testing in the long‐bone model demonstrated that PPF‐based bone‐graft substitute increased the flexural strength of K‐wire stabilized osteotomies. These results suggest that this type of bone graft substitute may have clinical utility in the stabilization of complex tubular bone fractures. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 311–317, 2003
Adsorption of parotid saliva proteins and adhesion of Streptococcus mutans ATCC 21752 to dental fiber‐reinforced composites
Authors: Tanner Johanna , Carlén Anette , Söderling Eva , Vallittu Pekka K. 
Published: June 2003

AbstractThe use of fiber‐reinforced composites (FRC) in dentistry has increased during recent years. In marginal areas of crowns and removable partial dentures the fibers may become exposed and come into contact with oral tissues, saliva, and microbes. To date, few articles have been published on oral microbial adhesion to FRCs. The aim of this study was to compare different FRCs, their components, and conventional restorative materials with respect to S. mutans ATCC 21752 adhesion and adsorption of specific S. mutans binding proteins. Surface roughness of the materials was also determined. Four different FRCs, a restorative composite, and a high‐leucite ceramic material were studied. Polyethylene FRC was found to be significantly rougher than all other materials. Aramid FRC also showed higher surface roughness in comparison with all materials but polyethylene FRC. Without a saliva pellicle, adhesion of S. mutans coincided with surface roughness and polyethylene and aramid FRC promoted S. mutans adhesion better than the other smoother materials. In the presence of salivary pellicle, ceramic and polyethylene FRC bound more bacteria than the other materials studied. Higher quantities of S. mutans binding proteins in the pellicles may in part account for the higher S. mutans adhesion to saliva‐coated ceramic and polyethylene FRC. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 391–398, 2003
The effect of 30% hydrogen peroxide on the color of compomers
Authors: Kwon Y. H. , Kwon T. Y. , Kim H. I. , Kim K. H. 
Published: June 2003

AbstractThe interaction between bleaching agents and recently introduced compomers has several issues that need to be explored, including morphology and mechanical properties. To investigate the effect of 30% hydrogen peroxide, a bleaching agent, on the color of compomers, three compomers (Compoglass F, Elan, and F2000) were polymerized, bleached up to 120 h, and then measured to determine the reflectance of the specimen during the bleaching process. Color differences were evaluated from the reflectance and color values that were represented by CIE L*a*b* values. Compomers stored in distilled water were used as a source of reference. Teeth were also used for comparison. Color differences for both the tested teeth and compomers and different periods of bleaching and soaking in distilled water showed statistically significant difference (p < 0.0001). Among the tested compomers, Compoglass F demonstrated the highest color difference. In addition, the color differences were maximal during the first 24 h. After 24 h, the color difference increased nearly linearly. Compomers stored in both a bleaching agent and distilled water did not exhibit much color difference between them. However, the color difference between teeth and compomers was considerable. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 306–310, 2003
Design and evaluation of novel blood incubation systems for in vitro hemocompatibility assessment of planar solid surfaces
Authors: Streller U. , Sperling C. , Hübner J. , Hanke R. , Werner C. 
Published: June 2003

AbstractSuccess in the development of hemocompatible biomaterials depends on adequate equipment and procedures for standardized analysis of blood–materials interactions in vitro. In view of the limited standard of knowledge on that important aspect, two novel incubation systems were designed, built, and evaluated for the in vitro assessment of the hemocompatibility of planar solid surfaces: A screening setup was introduced for the comparison of up to 12 different samples. A perfusion setup was developed to model the directed blood flow in the vascular system during incubation by a recirculation circuit, allowing the variation of the wall shear rate at the sample surface. The incubation procedures utilized freshly drawn, heparinized whole human blood. Hemocompatibility in terms of selected aspects of coagulation, thrombogenicity, and immune responses was quantified through plasma levels of characteristic molecules (immunoassays), cell counting, and analysis of adherent cells and fibrin formation (scanning electron microscopy), respectively. Prevention of blood–air contact and mechanical stress, constant temperature and blood pH during incubation, and the suitable choice of reference materials were found to be crucial for reliable testing. Considering those requirements, screening and perfusion system both provided sensitive discrimination between a given set of planar solid surfaces. In conclusion, the suggested methods for an in vitro hemocompatibility assessment permit versatile, sensitive, and efficient analysis of important blood–material interactions despite the unavoidable variability of blood characteristics in different experiments. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 379–390, 2003
Effect of chemical etching and aging in boiling water on the corrosion resistance of nitinol wires with black oxide resulting from manufacturing process
Authors: Shabalovskaya S. , Rondelli G. , Anderegg J. , Simpson B. , Budko S. 
Published: June 2003

AbstractThe effect of chemical etching in a HF/HNO3 acid solution and aging in boiling water on the corrosion resistance of Nitinol wires with black oxide has been evaluated with the use of potentiodynamic, modified potentiostatic ASTM F746, and scratch tests. Scanning‐electron microscopy, elemental XPS, and Auger analysis were employed to characterize surface alterations induced by surface treatment and corrosion testing. The effect of aging in boiling water on the temperatures of martensitic transformations and shape recovery was evaluated by means of measuring the wire electroresistance. After corrosion tests, as‐received wires revealed uniformly cracked surfaces reminiscent of the stress‐corrosion‐cracking phenomenon. These wires exhibited negative breakdown potentials in potentiostatic tests and variable breakdown potentials in potentiodynamic tests (− 100 mV to + 400 mV versus SCE). Wires with treated surfaces did not reveal cracking or other traces of corrosion attacks in potentiodynamic tests up to + 900–1400‐mV potentials and no pitting after stimulation at + 800 mV in potentiostatic tests. They exhibited corrosion behavior satisfactory for medical applications. Significant improvement of corrosion parameters was observed on the reverse scans in potentiodynamic tests after exposure of treated wires to potentials > 1000 mV. In scratch tests, the prepared surfaces repassivated only at low potentials, comparable to that of stainless steel. Tremendous improvement of the corrosion behavior of treated Nitinol wires is associated with the removal of defect surface material and the growth of stable TiO2 oxide. The role of precipitates in the corrosion resistance of Nitinol—scratch repassivation capacity in particular—is emphasized in the discussion. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 331–340, 2003
Fatigue testing and performance of acrylic bone‐cement materials: State‐of‐the‐art review
Authors: Lewis Gladius 
Published: June 2003

AbstractOver the past three decades or so, a very large volume of literature has been generated on the impact of an assortment of variables on the fatigue lifetimes of a large number of acrylic bone‐cement formulations. In the present article, this literature is examined critically to reveal areas of agreement, areas of disagreement, as well as a welter of underexplored and unexplored topics. For example, there is unanimity of support for the notion that an increase in the molecular weight of the powder constituents or the fully cured cement leads to an increase in the cement's fatigue life, whereas there is disagreement as to whether vacuum mixing the cement constituents leads to an increase in the fatigue life of the fully cured cement (relative to the hand‐mixed counterpart). Among the underexplored topics is systematic study of the effect of test frequency on the fatigue results, whereas determination of the optimal concentration of the antibiotic in an antibiotic‐loaded cement is an example of the unexplored topics. It is pointed out that resolving the controversies, addressing the underexplored topics, and filling the lacunae will allow comprehensive evaluations of acrylic bone‐cement materials to be made. This enhanced body of knowledge will prove invaluable in the continued use of acrylic bone cement as the anchoring agent in cemented arthroplasties. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 457–486, 2003
Effect of admixed high‐density polyethylene (HDPE) spheres on contraction stress and properties of experimental composites
Authors: Ferracane J. L. , Ferracane L. L. , Braga R. R. 
Published: June 2003

AbstractAdditives that provide stress relief may be incorporated into dental composites to reduce contraction stress (CS). This study attempted to test the hypothesis that conventional fillers could be replaced by high‐density polyethylene (HDPE) spheres in hybrid and nanofill composites to reduce CS, but with minimal effect on mechanical properties. Nanofill and hybrid composites were made from a Bis‐GMA/TEGDMA resin having either all silica nanofiller or 75 wt.% strontium glass + 5 wt.% silica and replacing some of the nanofiller or the glass with 0%, 5% (hybrid only), 10% or 20 wt.% HDPE. The surface of the HDPE was either left untreated or had a reactive gas surface treatment (RGST). Contraction stress (CS) was monitored for 10 min in a tensilometer (n = 5) after light curing for 60 s at 390 mW/cm2. Other specimens (n = 5) were light cured 40 s from two sides in a light‐curing unit and aged 1 d in water before testing fracture toughness (KIc), flexure strength (FS), and modulus (E). Results were analyzed by ANOVA with Tukey's multiple comparison test at p < 0.05. There was no difference between composites with RGST and untreated HDPE except for FS‐10% HDPE hybrid (RGST higher). An increased level of HDPE reduced contraction stress for both types of composites. Flexure strength, modulus (hybrid only), and fracture toughness were also reduced as the concentration of HDPE increased. SEM showed evidence for HDPE debonding and plastic deformation during fracture of the hybrid composites. In conclusion, the addition of HDPE spheres reduces contraction stress in composites, either through stress relief or a reduction in elastic modulus. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 318–323, 2003
Endotoxin contamination in wound dressings made of natural biomaterials
Authors: Nakagawa Y. , Murai T. , Hasegawa Chie , Hirata M. , Tsuchiya T. , Yagami T. , Haishima Y. 
Published: June 2003

AbstractContamination by endotoxin of nine kinds of wound dressings made of natural biomaterials (calcium alginate, collagen, chitin, and poly‐L‐leucine) was examined with the use of water extracts. By applying the Limulus amoebocyte lysate (LAL) test, high concentrations of endotoxin were detected in extracts from three kinds of products made of calcium alginate. These extracts evoked fever in rabbits and induced the release of a proinflammatory (pyrogenic) cytokine, interleukin‐6 (IL‐6), from human monocytic cells (MM6‐CA8). The effects disappeared when the extracts were treated with endotoxin‐removing gel column chromatography or with an endotoxin antagonist, B464, confirming that the contaminating pyrogen was endotoxin. A noteworthy finding was that one of the endotoxin‐containing extracts showed very weak IL‐6‐inducibility in human monocytic cells in contrast to its high pyrogenicity to rabbits. The discrepancy could be explained based on differences between humans and rabbits in sensitivity to the endotoxin, because the extract showed higher proinflammatory‐cytokine (TNF‐α)‐inducibility in rabbit whole‐blood cells (WBCs) than human WBCs. The results suggest that the LAL test is a useful method of detecting endotoxin contamination in wound dressings and the MM6‐CA8 assay is a good supplement to the LAL test for evaluating pyrogenicity in humans accurately. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 347–355, 2003
Titanium–cell interaction: Analysis of gene expression profiling
Authors: Carinci F. , Volinia S. , Pezzetti F. , Francioso F. , Tosi L. , Piattelli A. 
Published: June 2003

AbstractTitanium and its alloys are used worldwide in surgery. Dental implants, screws and plates, prostheses, and surgical instruments are made with titanium‐based metals. The favorable characteristics that make this material desirable for implantation are (a) mechanical proprieties and (b) biocompatibility. The latter has been demonstrated by in vivo studies with animal models and clinical trials over a 40‐year period. However, the exact effect of titanium on cells is still not well characterized. Expression profiling by DNA microarray is a new molecular technology that allows the analysis of gene expression in a cell system. Several genes whose expression was significantly up‐ or downregulated in an osteoblast‐like cell line (MG‐63) on titanium were identified with the use of DNA microarrays containing 19,200 genes. The differentially expressed genes are associated with a broad range of functional activities, including apoptosis, vesicular transport, and structural function. It was also possible to detect some genes whose function is unknown. The data reported are, to the author's knowledge, the first genetic portrait of titanium–cell interaction. They may help to provide a better understanding of the molecular mechanisms of titanium biocompatibility and serve as a model for studying the biocompatibility of other materials. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 341–346, 2003
Frontal sinus and skull bone defect obliteration with three synthetic bioactive materials. A comparative study
Authors: Peltola Matti J. , Aitasalo Kalle M. J. , Suonpää Jouko T. K. , Yli‐Urpo Antti , Laippala Pekka J. , Forsback Ari‐Pekka 
Published: June 2003

AbstractThree synthetic bioactive materials were studied in an experimental model to compare their usability in a frontal sinus and a skull bone defect obliteration. Bioactive glass number 9 (BAG1), bioactive glass number 13 (BAG2), and hydroxyapatite (HA) granules were investigated. BAG1 and HA granules have been previously tested clinically. The clinical usefulness of BAG2 granules has not been tested. Upper bony walls of 45 Elco rabbits' frontal sinuses were drilled open from four separate holes with the use of a standard method. The skull bone defects and the sinuses in frontal bone were filled with BAG1 or BAG2 on one side, and with HA on the other side. Two parallel posterior defects were covered with a pedicled periosteum flap, and two anterior defects with a free flap. The resorption of materials, new bone, and fibrous‐tissue formation were observed with a histomorphometric method at 1, 3, and 6 months postoperatively. Scanning‐electron microscopy (SEM) and Fourier‐transform infrared spectroscopy (FTIR) were done at 6 months. In histomorphometry, the new bone formation increased with all the investigated materials throughout the study (p < 0.001), but the results showed higher new bone formation in the defects filled with BAG1 than in corresponding BAG2‐ or HA‐ filled defects. New bone formation and resorption of materials were faster in defects covered by pedicled than by free periosteum flaps (p < 0.001). Intimate contact between the used materials and new bone was confirmed by SEM. FTIR analysis of bone produced by BAG1 and BAG2 was of the same type as natural frontal bone. BAG2 can be manufactured in various shapes, and thus, could possibly be used in clinical conditions requiring a special anatomical implant shape. However, more research is needed regarding this property of BAG2. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 364–372, 2003
Microleakage and interfacial morphology of self‐etching adhesives in class V resin composite restorations
Authors: Osorio Raquel , Toledano Manuel , de Leonardi Guillermo , Tay Franklin 
Published: June 2003

AbstractThe purpose of the study was to evaluate the marginal leakage of three adhesive systems in Class V resin composite restorations. Two adhesive systems containing acidic primers: Clearfil SE Bond (CSEB) and Etch & Prime 3.0 (E&P), were compared with a conventional water‐based primer: Scotchbond Multipurpose Plus (SBMP). Class V cavities were made at the cementum–enamel junction of extracted human molars, which were then divided between three groups. One of the adhesive systems was applied to each group following manufacturers' instructions. Composite restorations were placed, light cured for 40 s, and polished. Specimens were then immersed in a solution of 2% basic fuchsin dye for 24 h. Longitudinal sections were obtained and studied with a stereomicroscope for assessment of the microleakage according to the degree of dye penetration (scale of 0–3). Data were analyzed by Kruskal‐Wallis one‐way ANOVA, Mann‐Whitney tests, and the Wilcoxon matched‐pairs signed rank test. Two specimens for each group were analyzed by scanning‐electron microscopy (SEM). Bonded interfaces of dentin were also examined by transmission‐electron microscopy (TEM). On enamel, there were no significant differences between the three groups. On dentin, CSEB showed the lowest dye penetration values among the three adhesive systems. SEM and TEM studies showed hybrid layer and resin tag formations in all groups. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 399–409, 2003
Reduction of wear in total hip replacement prostheses by amorphous diamond coatings
Authors: Lappalainen Reijo , Selenius Mikko , Anttila Asko , Konttinen Yrjö T. , Santavirta Seppo S. 
Published: June 2003

AbstractWear‐debris–induced periprosthetic bone loss and aseptic loosening is regarded as the main long‐term problem of total hip replacements (THRs). In this study the amount of wear debris from articulating surfaces of THRs was reduced so as to be close to negligible by the use of high‐quality amorphous diamond (AD) coatings deposited by pulsed plasma arc techniques. The wear rates determined in a commercial hip simulator for 15 million walking cycles (corresponding to about 15 years of clinical use) in serum lubrication were even 1,000,000 times lower than the clinical values for conventional THRs (polyethylene–metal or metal–metal pairs). Elimination of wear debris and good biomechanical performance should provide a substantial improvement of the clinical longevity of the THRs. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 410–413, 2003
Bonded interface between a self‐curing resin and dentin primed with a metalloprotein
Authors: Taira Yohsuke , Matsumura Hideo , Atsuta Mitsuru 
Published: June 2003

AbstractThe purpose of this study was to investigate adhesive bonding between a self‐curing luting agent and dentin conditioned with a metalloprotein in terms of resin–dentin hybridization and interfacial polymerization. Of the six experimental primers containing bovine heart cytochrome c (BHCC), three contained 2‐hydroxyethylmethacrylate (HEMA) and the remaining three did not. The self‐curing luting agent used consisted of methyl methacrylate (MMA) and tri‐n‐butylborane (TBB) with or without 4‐methacryloyloxyethyl trimellitate anhydride (4‐META). Bovine dentin surfaces were etched with 10wt% phosphoric acid, primed, and then bonded with stainless steel rods. After 24 h of water storage, the optimum bond strength was obtained with the 4‐META/MMA‐TBB luting agent and the aqueous primer contained 0.1 μmol/g BHCC and 35wt% HEMA. Microscopic observations showed continuity among the luting agent, the hybridized dentin, and the dentin substrate. A model experiment suggested that BHCC accelerates the polymerization of the 4‐META/MMA/HEMA mixture from the hybridized dentin. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 66B: 414–418, 2003