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Biomedical subjects

Y Taira

Publications and source records attributed to Y Taira.

At least 19 recordsLinked to original sources

Dot pattern generation technique using molecular dynamics.

We have developed a new technique for generating homogeneously distributed irregular dot patterns useful for optical devices and digital halftoning technologies. To introduce irregularity, we use elaborately designed sequences called low-discrepancy sequences instead of pseudorandom numbers. We also use a molecular-dynamics redistribution method to improve the distribution of dots. Our method can produce arbitrary density distributions in accordance with a given design. The generated patterns are free from visible roughness as well as any moiré patterns when superimposed on other regular patterns. We demonstrate that our method effectively improves luminance uniformity and eliminates moiré patterns when used for a backlight unit of a liquid-crystal display.

Journal Article↗

Increased vascular endothelial growth factor peptide and gene expression in hypoplastic lung in nitrofen induced congenital diaphragmatic hernia in rats.

Persistent pulmonary hypertension (PPH) in congenital diaphragmatic hernia (CDH) lung has been shown to be associated with structural changes in the pulmonary vasculature, including medial and adventitial thickening. Vascular endothelial growth factor (VEGF) is a potent mitogenic and permeability factor targeting predominantly endothelial cells. mRNA encoding VEGF is detected in all fetal tissues and is most abundant in fetal lung, kidney, and liver. Recently, antenatal dexamethasone (Dex) treatment has been shown to prevent pulmonary-artery structural changes in experimentally-produced CDH. The aim of this study was to investigate mRNA and protein levels of VEGF in CDH lung and to determine whether antenatal Dex treatment has any effect on the production of VEGF. A CDH model was induced in pregnant rats following administration of 100 mg nitrofen on days 9.5 of gestation (term=22 days). Dex 0.25 mg/kg was given on day 18.5 and 19.5. Cesarean section was performed on day 21 of gestation. The fetuses were divided into three groups: normal controls (NC, n=8); nitrofen-induced CDH (CDH, n=8); and nitrofen-induced CDH with antenatal Dex treatment (CDH-Dex, n=8). Protein and mRNA were extracted from the whole lung. VEGF protein was measured by ELISA assay and mRNA expression was evaluated by reverse transcription-polymerase chain reaction. Immunohistochemistry using anti-rat VEGF antibody was also performed in each group. VEGF protein as well as mRNA expression were significantly increased in the CDH group compared to the NC group, which was not affected by antenatal Dex treatment. VEGF immunoreactivity in pulmonary vessel walls was increased in the CDH and CDH-Dex groups compared to the NC group. The enhanced VEGF protein and mRNA expression in CDH lung suggests that increased local synthesis of VEGF may be responsible for the structural changes in the pulmonary vasculature in CDH lung. VEGF expression in CDH lung is not downregulated by antenatal Dex treatment.

Analysis of Variance↗

Adhesive bonding of composite material to cast titanium with varying surface preparations.

The purpose of the present study was to evaluate the surface preparation effects of eight metal conditioners and an adhesive system on bonding between a prosthodontic composite material and cast titanium. Eight primers designed for conditioning base metal alloys (Acryl Bond, All-Bond 2 Primer B, Alloy Primer, Cesead II Opaque Primer, Eye Sight Opaque Primer, Metafast Bonding Liner, Metal Primer II, and MR Bond) as well as a surface modification technique (Siloc) were assessed. Disk specimens cast from titanium (T-Alloy H) were either primed with one of the eight primers or treated with the Siloc system, and then bonded with a light-activated composite material (Artglass). Bond durability was evaluated by thermocycling (4 and 60 degrees C, 1 min each, 20, 000 cycles). After thermocycling, two groups either primed with the Cesead II Opaque Primer material or treated with the Siloc system exhibited significantly greater bond strength (20.0 and 19.0 MPa) than the other groups (0.2-12.6 MPa, P < 0.05). These two systems are considered to be useful for improving bonding between the titanium and the composite material tested.

Adhesives↗

Effect of disinfectants containing glutaraldehyde on bonding of a tri-n-butylborane initiated resin to dentine.

The purpose of this study was to evaluate the effects of disinfectants on the bond strength of resin to dentine. The surface of bovine dentine was exposed to formaldehyde (FA) aqueous solutions, glutaraldehyde (GA) aqueous solutions, 2-hydroxyethyl methacrylate aqueous solutions (HEMA), a commercially available dentine primer (Gluma CPS desensitizer, GLUMA), isotonic sodium chloride solution (IS), and distilled water (DW), and placed in a humidor (HU) at 37 degrees C, or non-stored (baseline). All dentine surfaces were conditioned with a 10% citric acid and 3% ferric chloride solution (10-3 liquid), and then bonded to an acrylic rod with a self-curing adhesive resin (Super-Bond C&B). The mean tensile bond strengths determined 24 h after bonding were compared by analysis of variance (ANOVA) and Fisher's protected LSD test (n=5, P < or = 0.05). The exposure of dentine to IS, DW and HU for both 48 and 168 h resulted in a decrease in bond strength when compared with the baseline. The highest bond strengths after 168 h of exposure were obtained with 5% GA, 10% HEMA, and GLUMA, the values of which were equivalent to baseline and were significantly higher than that of FA. It is concluded that disinfectant pre-treatment with 5% GA or GLUMA stabilizes the bonding of tri-n-butylborane (TBB) initiated luting agent to bovine dentine conditioned with 10-3 liquid.

Acid Etching, Dental↗

Surface treatment of dentin with GLUMA and iron compounds for bonding indirect restorations.

The purpose of this study was to evaluate five dentin bonding systems simulating indirect restorations. The surface of bovine and human dentin was primed with a glutaraldehyde agent (GLUMA) and placed in a humidor at 37 degrees C for 168 h. In an experimental bonding system (GLUMA/CY/SB), the surfaces were etched with phosphoric acid, primed with cytochrome c, and then bonded to an acrylic rod with a self-curing resin (4-META/MMA-TBB). Specimens using two commercially available bonding systems [All-Bond 2 (AB2) and Super-Bond C & B (10-3/SB)] and two controls with and without GLUMA (GLUMA/10-3/SB and CY/SB) were also prepared. Tensile testing revealed that the bond strengths were influenced by the bonding system, 168 h dentin exposure and their interaction, but not by the tooth origin. AB2 showed the lowest bond strength. With the 10-3/SB system, exposing the dentin to humidity resulted in a decrease in bond strength. After 168 h of exposure, no significant differences were observed between 10-3/SB and CY/SB. The most effective bonding was obtained with the bonding systems of GLUMA/10-3/SB and GLUMA/CY/SB. Improved outcome is expected with these bonding systems when building up abutment teeth with indirect restorations.

Analysis of Variance↗

Adhesive bonding of titanium nitride-plated stainless steel for magnetic attachments.

The purpose of this study was to evaluate adhesive bonding of resin to titanium nitride ion-plated stainless steel in order for magnetic attachments to survive in the oral environment. Two primers, Cesead II Opaque Primer (CPII) and Metal Primer II (MPII), and one bonding agent, Super-Bond C&B (SB), were used. The surfaces of stainless steel disks were ground and then plated with titanium nitride. After the primer and SB resin were applied, a self-curing resin was bonded to the metal surfaces. Shear bond strengths were determined after 24 h of water storage and after 2,000 thermocycles. Titanium nitride ion-plated stainless steel showed bond strength comparable to the non-plated material. After thermocycling, all specimens of the group no primer/no SB were debonded. The bond strengths of groups CPII/no SB, MPII/no SB and no primer/SB were significantly lower bond strengths than groups CPII/SB and MPII/SB. An appropriate combination of primer and bonding agent should be selected when bonding a magnetic attachment to the denture base.

Adhesiveness↗

Effect of three adhesive primers on the bond strengths of four light-activated opaque resins to noble alloy.

The effect of commercial adhesive primers for noble metals on the bond strength of light-activated opaque resin has not been determined. This study evaluated the effect of three adhesive primers on the shear bond strengths of each of the four light-activated opaque resins to silver--palladium--copper--gold (Ag--Pd--Cu--Au) alloy. The adhesive primers Alloy Primer (AP), Metal Primer II (MPII) and Metaltite(MT) were used. Four commercial light-activated opaque resins (Axis (AX), Cesead II (CEII), Dentacolor(DE) and Solidex (SO) were used to bond a light-activated resin-veneered composite to Ag--Pd--Cu--Au alloy. The specimens were stored in water at 37 degrees C for 24 h and then immersed alternatively in water baths at 4 and 60 degrees C for 1 min each for up to 20,000 thermal cycles before shear mode testing at a cross-head speed of 0.5 mm min(-1). All the primers examined improved the shear bond strength between opaque resin and Ag--Pd--Cu--Au alloy compared with non-primed specimens prior to thermal cycling. After 20,000 thermal cycles, the bond strengths of combined use of AP and DE and that of MT and each of AX, CE or DE were significantly greater than any other groups. Significant difference was observed between the bond strengths at thermal cycles 0 and 20,000, with the combined use of MT and DE. With the combination of appropriate adhesive metal primers and light-activated opaque resins, complicated surface preparations of metal frameworks of resin-veneered prostheses that are composed of casting Ag-Pd-Cu-Au alloy may be negligible.

Adhesives↗

Effect of desensitizers on bond strength of adhesive luting agents to dentin.

The current study investigates the influence of three dentin hypersensitivity treating agents (Gluma CPS, MS Coat and Saforide) on bond strength to dentin of two luting agents (Panavia Fluoro Cement and Super-Bond C & B). Sixty bovine dentin substrates were divided into 12 combinations of four treatment conditions (Gluma CPS, MS Coat, Saforide and control) and three adhesive systems (AD Gel sodium hypochlorite + Panavia Fluoro Cement, Panavia Fluoro Cement without AD Gel and Super-Bond C & B). After bonding the treated teeth to steel rods, 24-h tensile bond strengths were determined, and average values (n=5) were compared by analysis of variance (ANOVA). Without application of the desensitizers, bond strengths of the two groups (Super-Bond C & B, 10.2 MPa; AD Gel + Panavia, 11.5 MPa) were comparable, and they were greater than the group bonded with the Panavia material with no AD Gel conditioning (7.1 MPa). Application of the Saforide ammoniated silver fluoride desensitizer reduced bond strength of both the Super-Bond and Panavia luting agents, whereas the MS Coat polymeric agent negatively affected bond strength of the Panavia cement only. The use of the Gluma desensitizer did not affect bond strength of any of the three adhesive systems, and the bond strength of the Panavia cement with the AD Gel conditioning was not reduced by application of any of the three desensitizers. The four combinations of two desensitizers (MS Coat and Gluma CPS) and two adhesive systems (Super-Bond C & B and AD Gel + Panavia) are deemed to be applicable to fixed prosthodontic treatment.

Acid Etching, Dental↗

Acclimation to the growth temperature and the high-temperature effects on photosystem II and plasma membranes in a mesophilic cyanobacterium, Synechocystis sp. PCC6803.

High-temperature effects on Photosystem II and plasma membranes, temperature dependence of growth, and acclimation to the growth temperature were studied in a mesophilic cyanobacterium, Synechocystis sp. PCC6803. The following results were obtained. (1) Small but distinct temperature acclimation of the PSII reaction center activity was shown for the first time when the activity was measured at inhibitory high temperatures. However, the reaction center activity showed no apparent acclimation when it was measured at growth temperatures after heat stress. (2) Oxygen-evolving activity and the permeability of plasma membranes showed higher resistance to heat when PCC6803 cells were grown at higher temperatures. (3) Acclimation of photosynthesis to the growth temperature seemed to occur so as to maintain photosynthesis activity not at a maximum level but in a certain range at the growth temperatures. (4) Neither sensitivity to high-temperature-induced dissociation of phycobilisomes from the PSII reaction center complexes nor degradation of phycocyanin were altered by changes in the environmental temperature. (5) A close relationship between the viability of cells and the structural changes of plasma membranes (but not the inactivation of photosynthesis) was observed. The denaturation process of PSII complexes and the relationship between the temperature dependence of the growth of Synechocystis PCC6803 cells and that of the photosynthetic activity are also discussed.

Cell Membrane↗

Properties of opaque resin composite containing coated and silanized titanium dioxide.

Titanium dioxide (TiO2) is mainly used as a pigment in opaque resin composites for application to the surface of a metal framework. The hypothesis in this paper is that particles of silica/alumina (SiO2/Al2O3)-coated TiO2 treated with a silane coupling agent could bond effectively with resin monomers of opaque resin composites. Untreated TiO2 was used as the control filler. Compressive and flexural strength specimens were prepared by the heat-curing method, because these bulk specimens could not be made by the typical photo-curing method. The treated composite had significantly higher compressive and flexural strengths than the untreated composite after 6 months' immersion in water. Scanning electron microscopy of the fractured composite surfaces showed an interface failure between TiO2 and resin for the untreated composite and cohesive failure within the resin for the treated composite after 6 months' immersion. The light-activated opaque resin composite containing treated TiO2 exhibited significantly higher bond strength to a noble dental alloy after 5000 thermal cycles than that containing untreated TiO2. Thus, silanized SiO2/Al2O3-coated TiO2 appears to be clinically useful as a filler of opaque resin composites.

Aluminum Oxide↗

Wear of luting materials with titanium retainer.

PURPOSE: The purpose of this study was to investigate the wear resistance of prosthodontic luting materials with a titanium framework by means of an in vitro three-bodied wear-testing device. MATERIALS AND METHODS: The surfaces of flat cast titanium disks were blasted with 50 microns alumina. Placing a 50 microns masking tape on the plane surface, the disks were bonded with five luting materials. The axial surfaces of the bonded disks were ground flat with 600 grit silicon-carbide paper, and then cyclically loaded (75.6 N, 1.2 Hz) by a chewing simulator for 400,000 cycles. The distance between titanium and cement surfaces was measured in micrometers by means of a profilometer to determine delta wear, and the surface texture was evaluated with a scanning electron microscope. RESULTS: The delta wear measurement showed that the resistance of Super-Bond Opaque adhesive was significantly higher than Panavia Fluoro adhesive and Fuji I cement after 400,000 wear cycles. No significant differences were detected among Super-Bond Opaque adhesive, Super-Bond adhesive, and All-Bond adhesive. Visually, continuity with the titanium framework was observed when the titanium disks were luted with resin systems.

Analysis of Variance↗

Participation of transcription elongation factor XSII-K1 in mesoderm-derived tissue development in Xenopus laevis.

We isolated a cDNA clone for a novel member of the S-II family of transcription elongation factors from Xenopus laevis. This S-II, named XSII-K1, is assumed to be the Xenopus homologue of mouse SII-K1 that we reported previously (Taira, Y., Kubo, T., and Natori, S. (1998) Genes Cells 3, 289-296). Expression of the XSII-K1 gene was found to be restricted to mesoderm-derived tissues such as liver, kidney, and skeletal muscle. Contrary to the general S-II gene, expression of the XSII-K1 gene was not detected in embryos at stages earlier than 11. The animal cap assay revealed that activin A, but not basic fibroblast growth factor, induced expression of the XSII-K1 gene and that it participated in the expression of mesoderm-specific genes such as Xbra and Xalpha-actin. This is the first demonstration that the regulation at the level of transcription elongation is included in the development of mesoderm-derived tissues.

Actins↗

Inclusion of phthalate esters by a self-assembled monolayer of thiolated cyclodextrin on a gold electrode

Complexation of phthalic acid esters (PAEs) by a self-assembled monolayer (SAM) of thiolated alpha-cyclodextrin (6-(2-mercaptoethylamino)-6-deoxy-alpha-cyclodextrin, MEA-alpha-CD) on a gold electrode was examined by a cyclic voltammetry using hydroquinone (HQ) as a probe. From the inhibitory effect of the phthalate esters on the inclusion of HQ by the surface-confined cyclodextrin (CD), the association constants (Kasn) of the esters with the immobilized CD were estimated. For comparison, the association of PAEs with free alpha-CD was examined spectrophotometrically using methyl orange as a probe. It was concluded that, in both free and surface-confined CD systems, the Kasn value increased with an increase in the length of aliphatic alcohols conjugated to phthalic acid. Furthermore, the Kasn values for PAEs in the SAM system were much larger than those in a free CD system. This could be intuitively ascribed to the steric factor for the PAEs to come out from the cavity of surface-confined CD, whose rim was in contact with the PAEs. Thermodynamic parameters indicated that the inclusion of PAEs in the SAM system was entropy-driven, which is different from the free CD system where the inclusion was favored by both enthalpy and entropy. This is partly due to the difficulties in cancellation of strain energy by the inclusion into the cavity of the densely fixed CD (97% of the calculated maximum) and partly due to the reduction of hydrogen bonding between the PAEs and the surface-confined CD. Desolvation of the PAEs and CD by the friction at the penetration into the cavity of CD, which was rigidly fixed to the electrode, might also contribute to the positive entropy change. These factors might emphasize the apolar factor of binding to be characterized by a favorable entropy change in the immobilized CD system.

Journal Article↗

Antenatal dexamethasone administration inhibits smooth-muscle-cell DNA synthesis in pulmonary-arterial media in nitrofen-induced congenital diaphragmatic hernia in rats.

The aim of this study was to investigate the effect of antenatal glucocorticoid therapy on smooth-muscle-cell (SMC) DNA synthesis in the pulmonary arteries (PA) in a nitrofen-induced congenital diaphragmatic hernia (CDH) rat model following nitrofen administration on day 9.5 of gestation. Antenatal dexamethasone (DEX) was given intraperitoneally on days 18.5 and 19.5 of gestation. Bromodeoxyuridine (BrdU) was injected via a jugular vein into the dam 1 h before the fetuses were killed by cesarean section at term. The fetuses were divided into three groups: group I (n = 10): normal controls; group II (n = 10): nitrofen-induced CDH; group III (n = 10): nitrofen-induced CDH with antenatal DEX treatment. Immunostaining of the lungs with anti-BrdU antibody was obtained by a standard avidin-biotin complex method. The number of immunopositive cells in the PA media and adventitia were counted using an image analyzer and analyzed statistically. The number of BrdU-immunopositive cells in the media was significantly increased in group II (16.83 +/- 3.01) compared to groups I (9.16 +/- 2.20) and III (6.83 +/- 1.70) (P < 0.01). There was no significant difference between groups I and III. The number of BrdU-immunopositive cells in the adventitia was not significantly different between the three groups. Antenatal DEX treatment inhibits SMC DNA synthesis in PA media in CDH lungs. This may be a possible mechanism by which antenatal DEX prevents structural PA changes in nitrofen-induced CDH in rats.

Animals↗

Administration of antenatal glucocorticoids upregulates peptide growth factor gene expression in nitrofen-induced congenital diaphragmatic hernia in rats.

BACKGROUND/PURPOSE: There is increasing evidence to suggest that various growth factors play a crucial role in fetal lung growth and morphogenesis. An array of peptide growth factors regulate cell proliferation, differentiation, and various other cell functions in the developing lung. The aim of this study was to investigate the effect of antenatal glucocorticoids administration on gene expression of basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF) and transforming growth factor (TGF)-beta1 in nitrofen-induced congenital diaphragmatic hernia (CDH) in rats. METHODS: A CDH model was induced in pregnant rats after administration of nitrofen. Dexamethasone (Dex; 0.25 mg/kg) was given intraperitoneally on day 18.5 and 19.5 of gestation (term, day 22). Cesarean section was performed on day 21 of gestation. mRNA was extracted from left lung and reverse transcription-polymerase chain reaction (RT-PCR) was performed to evaluate mRNA expression of each growth factors. Relative levels of mRNA were expressed as a ratio of the band density divided by that of beta-actin, a housekeeping gene known to be expressed at a constant level. RESULTS: Relative mRNA levels of bFGF and TGF-beta1 were decreased significantly in CDH lung compared with controls. Antenatal Dex treatment up-regulated gene expression of bFGF, PDGF, and TGF-beta1 in the hypoplastic CDH lung. CONCLUSIONS: The authors' findings suggest that decreased gene expression of bFGF, PDGF, and TGF-beta1 in the CDH lung may suppress lung growth and development. Increased gene expression of bFGF, PDGF, and TGF-beta1 in Dex-treated lung suggests that antenatal glucocorticoid administration may accelerate fetal lung growth by up-regulating these growth factors.

Animals↗

Antenatal dexamethasone enhances endothelin receptorB expression in hypoplastic lung in nitrofen-induced diaphragmatic hernia in rats.

BACKGROUND/PURPOSE: The hypoplastic lung and persistent pulmonary hypertension (PPH) are the principle causes of high mortality and morbidity in infants with congenital diaphragmatic hernia (CDH). Endothelin-1 (ET-1), which is produced by vascular endothelial cells and some leukocytes, plays a key role in modulating pulmonary vascular tone in PPH. Two different receptors (ET(A) and ET(B)) for ET-1 have been characterized. Binding of ET-1 to ET(A), which is present on smooth muscle cells in fetal lung, results in vasoconstriction. However, binding of ET-1 to ET(B), which is present on endothelial cells results in vasodilation mediated by endogenous nitric oxide. Antenatal glucocorticoid therapy has been shown to prevent abnormal pulmonary arterial structural changes in animal model with CDH. The aim of this study was to investigate the effect of antenatal glucocorticoid administration on ET-1 system in nitrofen-induced CDH hypoplastic lung in rats. METHODS: A CDH model was induced in pregnant rats after administration of nitrofen on day 9.5 of gestation. Dexamethasone (Dex) was given intraperitoneally on days 18.5 and 19.5 of gestation. Cesarean section was performed on day 21 of gestation. Rat ET-1 protein expression was measured in solubilized lung tissue extracts, by sandwich type enzyme-linked immunosorbent assay (ELISA) analysis. Reverse transcription polymerase chain reaction was performed to evaluate the relative amount of ET-1, ET(A), and ET(B) mRNA expression. RESULTS: The ET-1 protein and mRNA expression of ET-1 and both receptors were increased significantly in CDH lung compared with controls. Although there was no significant difference in ET(A) mRNA expression between CDH lung with Dex treatment and without Dex treatment, ET(B) mRNA expression was elevated significantly in CDH lung with Dex treatment compared with CDH lung without Dex treatment. CONCLUSION: These findings suggest that antenatal glucocorticoid therapy may modulate pulmonary vascular tone in CDH hypoplastic lung by selectively upregulating local expression of ET(B).

Animals↗

Incipient cauda equina syndrome as a model of somatovisceral pain in dogs: spinal cord structures involved as revealed by the expression of c-fos and NADPH diaphorase activity.

Segmental and laminar distribution of Fos-like immunoreactive, reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd)-exhibiting and double-labeled (Fos-like immunoreactive and NADPHd-exhibiting) neurons was examined in lower lumbar and sacral segments of the dog spinal cord using the model of multiple cauda equina constrictions. NADPHd histochemistry was used as marker of nitric oxide synthase-containing neurons. The appearance and the time-course of Fos-like immunoreactive, NADPHd and double-labeled neurons was studied at 2 h and 8 h postconstriction characterized as the incipient phase of cauda equina syndrome. The occurrence of Fos-like immunoreactive and NADPHd-exhibiting neurons in fully developed cauda equina syndrome was studied at five days postconstriction. An increase in Fos-like immunoreactivity in superficial laminae (I-II) and an enhanced NADPHd staining of lamina VIII neurons were found. A statistically significant increase in Fos-like immunoreactive neurons was found in laminae I-II and VIII-X 8 h postconstriction, and in contrast, a prominent decrease in Fos-like immunoreactive neurons was found in laminae I-II, accompanied by a statistically significant increase in Fos-like immunoreactive neurons in more ventrally located laminae VII-X at five days postconstriction. Quantitative analysis of laminar distribution of constriction-induced NADPHd-exhibiting neurons revealed a considerable increase in these neurons in laminae VIII-IX 8 h postconstriction and a statistically highly significant increase in NADPHd-exhibiting neurons in laminae VII-X five days postconstriction. Concurrently, the number of NADPHd-exhibiting neurons in laminae I-II was greatly reduced. While a low number of double-labeled neurons was found throughout the gray matter of lower lumbar and sacral segments at 2 h postconstriction, a statistically significant number of double-labeled neurons was found in lamina X 8 h and in laminae VII-X five days postconstriction. The course and distribution of anterograde degeneration resulting five days after multiple cauda equina constrictions are compared with segmental and laminar distribution of Fos-like immunoreactive and NADPHd-exhibiting neurons. Prominent involvement of the spinal cord neurons appearing in the lumbosacral segments at the early beginning and in fully developed cauda equina syndrome results in a Fos-like immunoreactivity and strongly enhanced NADPHd staining of some neuronal pools. Under such circumstances, an early cauda equina decompression surgery is advisable aimed at decreasing or preventing the derangement of the neural circuits in the lumbosacral segments.

Animals↗

Adhesive bonding of titanium with a thione-phosphate dual functional primer and self-curing luting agents.

A consistent bond between the metal framework and the luting agent is desired when resin-bonded prostheses are constructed with titanium. The purpose of this study was to evaluate three different metal primers on titanium bonding. Two sources of titanium (machined 99.9% titanium and cast Titan Ingot JS2) were used. Disk specimens were bonded with eight combinations of three primers and two luting agents (Panavia 21 and Super-Bond C&B), including two controls. Shear bond strengths were determined after 24-h water storage and after 10,000 cycles of thermocycling. Bond strengths were influenced by thermocycling, primer, luting agent and their combinations, but no significant differences were found between the machined 99.9% titanium and the cast ingot. The thione-phosphate dual functional primer (Alloy Primer) was comparable to the phosphate primer (Cesead II Opaque Primer) and the thiophosphate primer (Metal Primer II) for bonding the titanium metals examined. The most durable bond was obtained in three combinations of these primers and one luting agent (Super-Bond C&B).

Analysis of Variance↗