150 results on '"Cooley, R L"'
Search Results
2. TRADE AGREEMENTS EDUCATIONALLY
- Author
-
COOLEY, R. L., HAAREN, JOHN H., and ROBERTS, WILLIAM M.
- Published
- 1914
3. Evidence for a central origin of the low-frequency oscillation in RR-interval variability.
- Author
-
Cooley, R L, Montano, Nicola, Cogliati, C, Van De Borne, Philippe, Richenbacher, W, Oren, R, Somers, Virend Kristen, Cooley, R L, Montano, Nicola, Cogliati, C, Van De Borne, Philippe, Richenbacher, W, Oren, R, and Somers, Virend Kristen
- Abstract
Short-term variability of RR interval and blood pressure occurs predominantly at low frequency (LF; approximately 0.1 Hz) and high frequency (approximately 0.25 Hz). The arterial baroreflex is thought to be the predominant determinant of the LF component of RR variability. Patients with severe congestive heart failure (CHF) have an attenuated or absent LF oscillation in RR variability. The left ventricular assist device (LVAD) offers a unique possibility for analysis of spectral oscillations in RR interval independent of any effects of blood pressure that influence these oscillations via the baroreflex., Case Reports, Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S., info:eu-repo/semantics/published
- Published
- 1998
4. Cigarette smoking increases sympathetic outflow in humans.
- Author
-
Narkiewicz, K, Van De Borne, Philippe, Hausberg, M, Cooley, R L, Winniford, M D, Davison, D E, Somers, Virend Kristen, Narkiewicz, K, Van De Borne, Philippe, Hausberg, M, Cooley, R L, Winniford, M D, Davison, D E, and Somers, Virend Kristen
- Abstract
It is generally accepted that smoking increases blood pressure and inhibits muscle sympathetic nerve activity (SNA). The decrease in muscle SNA with cigarette smoking might be secondary to baroreflex responses to the pressor effect of smoking, thus obscuring a sympathetic excitatory effect of smoking. We tested the hypothesis that smoking increases sympathetic outflow., Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S., info:eu-repo/semantics/published
- Published
- 1998
5. Sympathetic activity in obese subjects with and without obstructive sleep apnea.
- Author
-
Narkiewicz, K, Van De Borne, Philippe, Cooley, R L, Dyken, M E, Somers, Virend Kristen, Narkiewicz, K, Van De Borne, Philippe, Cooley, R L, Dyken, M E, and Somers, Virend Kristen
- Abstract
Obese humans are reported to have increased muscle sympathetic nerve activity (MSNA). Obstructive sleep apnea (OSA) may also be accompanied by increased MSNA. Because there is a high prevalence of OSA in obese humans, it is possible that high MSNA reported in obese subjects may in fact reflect the presence of OSA in these subjects. We tested the hypothesis that obesity, per se, in the absence of OSA, is not accompanied by increased MSNA., Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S., info:eu-repo/semantics/published
- Published
- 1998
6. Alcohol potentiates orthostatic hypotension : implications for alcohol-related syncope.
- Author
-
Narkiewicz, K, Cooley, R L, and Somers, V K
- Published
- 2000
7. Bias and Uncertainty in Regression-Calibrated Models of Groundwater Flow in Heterogeneous Media
- Author
-
Cooley, R. L. and Steen Christensen
- Subjects
Nonlinearity ,Correction factor ,Bias ,Groundwater model ,Prediction interval ,Confidence interval ,Uncertainty ,Regression ,Heterogeneous media - Abstract
Groundwater models need to account for detailed but generally unknown spatial variability (heterogeneity) of the hydrogeologic model inputs. To address this problem we replace the large, m-dimensional stochastic vector β that reflects both small and large scales of heterogeneity in the inputs by a lumped or smoothed m-dimensional approximation γθ*, where γ is an interpolation matrix and θ* is a stochastic vector of parameters. Vector θ* has small enough dimension to allow its estimation with the available data. The consequence of the replacement is that model function f(γθ*) written in terms of the approximate inputs is in error with respect to the same model function written in terms of β, f(β), which is assumed to be nearly exact. The difference f(β) – f(γθ*), termed model error, is spatially correlated, generates prediction biases, and causes standard confidence and prediction intervals to be too small. Model error is accounted for in the weighted nonlinear regression methodology developed to estimate θ* and assess model uncertainties by incorporating the second-moment matrix of the model errors into the weight matrix. Techniques developed by statisticians to analyze classical nonlinear regression methods are extended to analyze the revised method. The analysis develops analytical expressions for bias terms reflecting the interaction of model nonlinearity and model error, for correction factors needed to adjust the sizes of confidence and prediction intervals for this interaction, and for correction factors needed to adjust the sizes of confidence and prediction intervals for possible use of a diagonal weight matrix in place of the correct one. If terms expressing the degree of intrinsic nonlinearity for f(β) and f(γθ*) are small, then most of the biases are small and the correction factors are reduced in magnitude. Biases, correction factors, and confidence and prediction intervals were obtained for a test problem for which model error is large to test robustness of the methodology. Numerical results conform with the theoretical analysis.
8. Industry's interest in the education of the child--Abridged
- Author
-
Cooley, R. L., primary
- Published
- 1926
- Full Text
- View/download PDF
9. Trade Agreements in Industrial Education
- Author
-
Cooley, R. L., primary
- Published
- 1914
- Full Text
- View/download PDF
10. Sympathetic activity in obese subjects with and without obstructive sleep apnea.
- Author
-
Narkiewicz K, van de Borne PJ, Cooley RL, Dyken ME, and Somers VK
- Subjects
- Adult, Analysis of Variance, Case-Control Studies, Female, Humans, Linear Models, Male, Polysomnography, Prevalence, Reference Values, Sleep Apnea Syndromes etiology, Muscle, Skeletal blood supply, Obesity physiopathology, Sleep Apnea Syndromes physiopathology, Sympathetic Nervous System physiology
- Abstract
Background: Obese humans are reported to have increased muscle sympathetic nerve activity (MSNA). Obstructive sleep apnea (OSA) may also be accompanied by increased MSNA. Because there is a high prevalence of OSA in obese humans, it is possible that high MSNA reported in obese subjects may in fact reflect the presence of OSA in these subjects. We tested the hypothesis that obesity, per se, in the absence of OSA, is not accompanied by increased MSNA., Methods and Results: We measured MSNA in 25 healthy normal-weight subjects and 30 healthy sedentary obese subjects. All subjects were screened by history and examination to exclude subjects with OSA or hypertension. OSA was further excluded by overnight polysomnographic studies. Despite careful screening, polysomnography revealed that 1 of 25 normal-weight subjects and 9 of 30 obese subjects had occult OSA (P=0.015). MSNA was similar in normal-weight subjects (41+/-3 bursts per 100 heartbeats) and obese subjects without sleep apnea (42+/-3 bursts per 100 heartbeats, P=0.99). MSNA in the 9 obese subjects with occult OSA was 61+/-8 bursts per 100 heartbeats, which was higher than MSNA in normal-weight subjects without sleep apnea (P=0.02) and higher than MSNA in obese subjects without sleep apnea (P=0.02)., Conclusions: Obesity alone, in the absence of OSA, is not accompanied by increased sympathetic activity to muscle blood vessels.
- Published
- 1998
- Full Text
- View/download PDF
11. Evidence for a central origin of the low-frequency oscillation in RR-interval variability.
- Author
-
Cooley RL, Montano N, Cogliati C, van de Borne P, Richenbacher W, Oren R, and Somers VK
- Subjects
- Adult, Autonomic Nervous System physiology, Blood Pressure physiology, Brain physiology, Heart Failure physiopathology, Heart Failure surgery, Heart-Assist Devices, Humans, Male, Middle Aged, Oscillometry, Postoperative Period, Respiration physiology, Heart Rate physiology
- Abstract
Background: Short-term variability of RR interval and blood pressure occurs predominantly at low frequency (LF; approximately 0.1 Hz) and high frequency (approximately 0.25 Hz). The arterial baroreflex is thought to be the predominant determinant of the LF component of RR variability. Patients with severe congestive heart failure (CHF) have an attenuated or absent LF oscillation in RR variability. The left ventricular assist device (LVAD) offers a unique possibility for analysis of spectral oscillations in RR interval independent of any effects of blood pressure that influence these oscillations via the baroreflex., Methods and Results: We performed spectral analysis of RR, blood pressure, and respiration in 2 patients with CHF before and after LVAD implantation. LF components of the RR-interval and blood pressure variability were absent in both CHF patients before LVAD implantation. After LVAD implantation, spectral analysis of the RR interval showed restoration of a clear and predominant LF oscillation in the native hearts of both patients, with no such oscillation evident in the blood pressure profile., Conclusions: During total circulatory support with the LVAD, the LF oscillation in RR interval of the native heart, absent in CHF, is restored. This LF oscillation in RR interval occurs in the absence of LF oscillations in blood pressure and thus is unlikely to be explained by baroreflex mechanisms. Hence, the absence of LF oscillation in the RR interval in CHF is functional and is reversible by LVAD circulation. The presence of a predominant LF oscillation in RR interval independent of any oscillation in blood pressure suggests that the LF oscillation is a fundamental property of central autonomic outflow.
- Published
- 1998
- Full Text
- View/download PDF
12. Cigarette smoking increases sympathetic outflow in humans.
- Author
-
Narkiewicz K, van de Borne PJ, Hausberg M, Cooley RL, Winniford MD, Davison DE, and Somers VK
- Subjects
- Adult, Antihypertensive Agents pharmacology, Blood Pressure drug effects, Blood Pressure physiology, Central Venous Pressure drug effects, Central Venous Pressure physiology, Female, Heart Rate drug effects, Heart Rate physiology, Humans, Lower Body Negative Pressure, Male, Muscles innervation, Nitroprusside pharmacology, Skin innervation, Sympathetic Nervous System drug effects, Smoking, Sympathetic Nervous System physiology
- Abstract
Background: It is generally accepted that smoking increases blood pressure and inhibits muscle sympathetic nerve activity (SNA). The decrease in muscle SNA with cigarette smoking might be secondary to baroreflex responses to the pressor effect of smoking, thus obscuring a sympathetic excitatory effect of smoking. We tested the hypothesis that smoking increases sympathetic outflow., Methods and Results: We examined the effects of sham smoking, cigarette smoking, and cigarette smoking in combination with nitroprusside on muscle (baroreflex-dependent) SNA in 10 healthy habitual smokers. The 3 sessions were performed in random order, each study on a separate day. In an additional study, we also investigated the effects of sham smoking and cigarette smoking on skin (baroreflex-independent) SNA in 9 subjects. Compared with sham smoking, cigarette smoking alone increased blood pressure and decreased muscle SNA. When the blood pressure increase in response to smoking was blunted by nitroprusside infusion, there was a striking increase in muscle SNA. Muscle SNA increased up to 3-fold the levels seen before smoking (P<0.001), accompanied by an increase in heart rate of up to 37+/-4 bpm. Cigarette smoking also induced a 102+/-22% increase in skin SNA (P=0.03)., Conclusions: These data provide the first direct evidence that cigarette smoking increases sympathetic outflow.
- Published
- 1998
- Full Text
- View/download PDF
13. Effect of thermocycling times on dentin bond strength.
- Author
-
Burger KM, Cooley RL, and Garcia-Godoy F
- Subjects
- Analysis of Variance, Composite Resins, Hot Temperature, Humans, Materials Testing, Methacrylates, Dental Bonding, Dentin-Bonding Agents chemistry, Resin Cements
- Abstract
Thermocycling is widely used in the evaluation of dentin bonding agents. The purpose of this study was to determine the effect of increasing thermocycling times on the shear bond strength of composite resin to dentin using a NTG-GMA/BPDM-type bonding agent. Fifty human molar teeth were ground flat on the buccal surface into dentin (600 grit). Ten specimens were prepared for each thermocycling group of 100, 500, 1000, 2000, and 4000 cycles. The adhesive agent was applied to the dentin according to the manufacturer's instructions. A cyclindrical-shaped matrix was used to form the composite resin that was light cured to the treated dentin surface for 60 seconds. Thermocycling was started after 24 hours of storage in deionized water at 37 degrees C. Shear bond strengths were determined with an Instron universal testing machine at a cross-head speed of 0.5 mm per minute. The bond strengths in megapascals (MPa) were : 100 cycles 18.1 (+/- 5.2) MPa, 500 cycles 19.4 (+/- 4.0)MPa, 1000 cycles 16.5 (+/- 2.9), 2000 cycles 14.6 (+/- 5.1), and 4000 cycles 19.9 (+/- 3.2)MPa. When this data was subjected to an ANOVA, no significant difference was found between the groups.
- Published
- 1992
- Full Text
- View/download PDF
14. Porcelain to dentin bond strength with a dentin adhesive.
- Author
-
Tseng EY, Cooley RL, and Evans JG
- Subjects
- Analysis of Variance, Humans, Materials Testing, Tensile Strength, Composite Resins, Dental Bonding, Dental Enamel, Dental Porcelain, Dentin, Dentin-Bonding Agents, Methacrylates
- Abstract
Adhesion of porcelain to dentin may be important in those cases with little remaining enamel. The purpose of this study was to determine the bond strength of porcelain to dentin using a dentin adhesive (All-Bond) and compare it to the enamel bond strength. Sixty human molar teeth had either a dentin or enamel bonding site prepared by flat grinding to a 600 grit. The teeth were divided into three groups of 20 each. Sixty porcelain cylinders were prepared, hydrofluoric acid etched on one end and silane treated. Twenty of the cylinders were bonded to enamel, 20 bonded to dentin with a dentin adhesive to be tested at 48 hours, and 20 bonded to dentin with a dentin adhesive to be tested after 24 hours of thermocycling (800 cycles at 6 degrees C to 60 degrees C). The specimens were tested in an Instron at a crosshead speed of 0.5 mm/minute. The following bond strengths were found: enamel (19.0 +/- 2.9 MPa), dentin at 48 hours (14.4 +/- 5.4 MPa), and dentin after thermocycling (10.1 +/- 3.8 MPa). When this data was subjected to statistical analysis (ANOVA), there was a significant difference between the groups. A Scheffe's test found that the dentin-porcelain bond at 48 hours was stronger than the thermocycled group, and that the enamel bond was significantly stronger than the two dentin bonds.
- Published
- 1992
- Full Text
- View/download PDF
15. Shear bond strengths of resin adhesive cements to dentin and Ni-Cr-Be alloy.
- Author
-
Cooley RL, Barkmeier WW, and Evans JG
- Subjects
- Dentin, Humans, Materials Testing, Phosphates, Tensile Strength, Boron Compounds, Chromium Alloys, Dental Bonding, Dental Cements, Dentin-Bonding Agents, Methacrylates, Methylmethacrylates, Resin Cements
- Abstract
Two adhesives, Super Bond and Panavia, were evaluated for shear bond strength to dentin. Twenty human teeth were used for each adhesive. Bonding sites were prepared in dentin (600 grit) and the adhesives applied according to the manufacturers' instructions. Bond strengths were determined with an Instron testing machine at 24 hours. Super Bond developed the strongest bond of 21.59 +/- 3.91 MPa. Panavia produced a lower bond strength of 2.68 +/- 1.45 MPa. Statistically, Super Bond was found to have a stronger bond than Panavia. The same two adhesives were applied to Ni-Cr-Be specimens and compared to Comspan. Twenty Rexillium III specimens were used for each adhesive at 24 hours and 20 for thermocycling. The metal specimens were ground flat (600 grit) and then air abraded with 50-micron aluminous oxide. The adhesives were applied to the metal surface in accordance with the manufacturers' instructions. One group was tested at 24 hours while the second group was tested after thermocycling (2,500 cycles at 6 degrees C to 60 degrees C). At 24 hours, Super Bond had a significantly stronger bond than the other materials. Comparison of the 24-hour to thermocycled bond strengths found Comspan had a significant increase in bond strength, Panavia had no significant change and Super Bond had a significant decrease in bond strength. After 2,500 thermocycles, Comspan, Panavia, and Super Bond were not significantly different in bond strength.
- Published
- 1992
- Full Text
- View/download PDF
16. Laboratory evaluation of adhesive systems.
- Author
-
Barkmeier WW and Cooley RL
- Subjects
- Adhesives chemistry, Bisphenol A-Glycidyl Methacrylate chemistry, Composite Resins chemistry, Dental Enamel, Dentin, Humans, Materials Testing, Dental Bonding, Dental Cements chemistry, Dental Leakage, Dentin-Bonding Agents chemistry
- Abstract
Adhesive bonding of resin materials to acid-conditioned enamel is a clinically proven technique in preventative, restorative, and orthodontic procedures. Laboratory evaluations of etched-enamel resin bonding have shown excellent bond strengths and the virtual elimination of marginal microleakage. Adhesion to dentin has been more of a challenge. Earlier-generation dentin bonding systems did not yield high bond strengths in the laboratory or prevent marginal microleakage. Newer-generation adhesive systems generally use a dentin conditioner to modify or remove the smear layer and a subsequent application of an adhesive resin bonding agent. Laboratory evaluations of newer systems have shown bond strengths that approach or actually exceed that of etched enamel resin bonding. Bond strengths have improved with the evolution of dentin bonding systems, and microleakage from the cementum/dentin margin has been significantly reduced or prevented with the newer systems. Although laboratory testing of adhesive systems provides a mechanism to screen and compare newly developed systems, clinical trials are essential to document long-term clinical performance.
- Published
- 1992
17. Dentinal bond strengths and microleakage of a 4-META adhesive to amalgam and composite resin.
- Author
-
Cooley RL, Tseng EY, and Barkmeier WW
- Subjects
- Coloring Agents, Composite Resins, Dental Alloys, Dental Amalgam, Dental Cavity Lining, Dental Materials, Dental Stress Analysis, Humans, Materials Testing, Organic Chemicals, Tensile Strength, Dental Bonding, Dental Leakage diagnosis, Dentin, Methacrylates
- Abstract
A 4-META-containing adhesive was evaluated for its ability to bond a composite resin and two types of amalgam to dentin. One group of composite resin was tested after 24 hours and another group after 24 hours of thermocycling. Shear bond strengths were: composite resin at 24 hours = 22.38 MPa; thermocycled composite resin = 20.86 MPa; spherical alloy = 3.38 MPa; admixed alloy = 3.84 MPa. Microleakage was evaluated after the 4-META adhesive was applied to cavity preparations and compared to that of a group treated with a cavity varnish. There was statistically significantly less microleakage in the 4-META group at both the occlusal and gingival margins.
- Published
- 1991
18. Comparison of manually and mechanically mixed glass ionomers.
- Author
-
Cooley RL and Train TE
- Subjects
- Analysis of Variance, Dental Alloys chemistry, Dental Cavity Preparation, Dental Stress Analysis, Dentin, Humans, Maleates chemistry, Materials Testing, Methylene Blue, Stress, Mechanical, Surface Properties, Dental Bonding, Dental Leakage, Glass Ionomer Cements chemistry
- Abstract
Two mechanically mixed glass ionomer restorative materials (Ketac-Fil and Fuji Cap II) were compared with two manually mixed products (Chelon-Fil and Fuji Type II). One manually mixed material was substantially weaker than the others in bond strength tests. No significant differences in microleakage were found among the materials.
- Published
- 1991
- Full Text
- View/download PDF
19. Fluoride-releasing retainers.
- Author
-
McCourt JW and Cooley RL
- Subjects
- Humans, Fluorides, Topical administration & dosage, Methacrylates, Orthodontic Appliance Design, Orthodontic Appliances, Removable, Polyurethanes
- Abstract
A method for fabrication of a fluoride-releasing retainer is described. The insert releases low levels of fluoride, which should promote remineralization and reduce caries potential. Previous research on the amount of fluoride release is also discussed.
- Published
- 1991
- Full Text
- View/download PDF
20. Bond strength of light-cure fluoride-releasing base-liners as orthodontic bracket adhesives.
- Author
-
McCourt JW, Cooley RL, and Barnwell S
- Subjects
- Acid Etching, Dental, Bicuspid, Delayed-Action Preparations, Dental Cements chemistry, Fluorides administration & dosage, Glass Ionomer Cements chemistry, Humans, Sodium Fluoride chemistry, Stress, Mechanical, Tensile Strength, Time Factors, Urethane analogs & derivatives, Urethane chemistry, Adhesives chemistry, Bisphenol A-Glycidyl Methacrylate, Dental Bonding, Fluorides chemistry, Orthodontic Appliances
- Abstract
Fluoride-releasing bracket adhesives are desirable for their ability to minimize the potential for subsurface enamel demineralization adjacent to a bonded bracket. Self-applications with topical fluoride rinses, pastes, and gels have been documented to minimize and eliminate subsurface caries adjacent to bonded brackets. However, the success of these mediums are limited by patient compliance. A urethane with fluoride (TimeLine) and a glass ionomer with methyl methacrylate (Vitrabond), both of which are light cured and exhibit sustained fluoride ion release, were compared with a non-fluoride-releasing light-cured bracket adhesive (Transbond). Premolar brackets with mesh pads (A-Company) were positioned on the buccal surface of the premolars and placed in a PVC ring with polymethyl methacrylate. Two groups of 10 samples each of the tested material were prepared and immersed in distilled water immediately after in vitro bonding. Samples of each material were evaluated for enamel shear strength (Instron) at 24 hours and at 30 days. Bond strengths to enamel at 24 hours measured in megapascals (MPa) were 5.98 for TimeLine, 11.58 for Vitrabond, and 11.35 for Transbond. Bond strength to enamel at 30 days was found to be significantly less for TimeLine and Vitrabond: 3.05 for TimeLine, 5.39 for Vitrabond, and 10.80 for Transbond. The two fluoride-releasing, light-cured materials tested have low bond strengths after 30 days and are not acceptable as orthodontic bracket bonding agents. However, for patients with high caries risk, these materials may be placed around already bonded brackets.
- Published
- 1991
- Full Text
- View/download PDF
21. Shear bond strength to dentin and Ni-Cr-Be alloy with the All-Bond universal adhesive system.
- Author
-
Barkmeier WW, Suh BI, and Cooley RL
- Subjects
- Acid Etching, Dental, Hot Temperature, Humans, Materials Testing, Nickel, Phosphoric Acids, Succinic Anhydrides, Tensile Strength, Chromium Alloys, Composite Resins, Dental Bonding methods, Dental Cements, Dentin, Methacrylates
- Abstract
The shear bond strength of the All-Bond system to dentin and a nonprecious alloy was evaluated. Eighty human molar teeth (10 per group) were used in the dentin bonding phase of the study. A bond site was prepared in dentin, and both the succinic anhydride modified HEMA and 10 percent phosphoric acid dentin conditioning techniques were evaluated under both wet and dry conditions. Eighty Rexillium III specimens were used in the metal bonding phase of the study. All-Bond primer and opaquer were applied to the metal surface, followed by a visible light-cured composite restorative material. Dentin bond strengths were determined at 24 hours, while metal bond strengths were evaluated both at 24 hours and after thermocycling (2,500 cycles). Separate groups were established for adhesion to both dentin and metal with the composite placed in a plastic matrix or a gelatin capsule. The highest mean shear bond values to dentin were obtained in the groups with the gelatin capsule bonding procedure, where the dentin was treated with 10 percent phosphoric acid and then blotted dry (wet technique) before the bonding procedure (39.99 MPa). These values were higher than the succinic anhydride modified HEMA-treated group with gentle air drying (wet technique-29.56 MPa). There was essentially no difference in mean shear bond strengths to dentin when a succinic anhydride modified HEMA dentin conditioner was used with aggressive (dry technique) or gentle air drying (wet technique) [29.56 versus 29.08 MPa]. High bond strengths to Rexillium III were obtained when the All-Bond adhesive system was used in combination with a dual-care opaquer and a composite restorative material.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1991
- Full Text
- View/download PDF
22. Current status of adhesive resin systems.
- Author
-
Barkmeier WW and Cooley RL
- Subjects
- Humans, Adhesives chemistry, Dental Bonding, Resins, Synthetic chemistry, Tooth
- Abstract
The advanced third-generation bonding agents have created excitement as they have the potential to develop effective dentin bonding. These materials have shown better bond strengths and less marginal microleakage than the previous generations of adhesives. Enamel acid etching and the new primer/adhesive systems can enhance the retention rates of resin restorations and reduce or eliminate marginal microleakage.
- Published
- 1991
23. Effect of dentin adhesives on sealant bond strength.
- Author
-
Garcia-Godoy F, Cooley RL, Ranly DM, and Burger KM
- Subjects
- Acrylic Resins, Analysis of Variance, Bisphenol A-Glycidyl Methacrylate, Glutaral, Humans, Polymethacrylic Acids, Tensile Strength, Boron Compounds, Dental Cements, Methacrylates, Methylmethacrylates, Resin Cements
- Abstract
This study evaluated the effect of four dentin adhesives on sealant shear bond strength. Five groups of 15 human extracted teeth (75 in total) were prepared to receive the following treatments: group 1, sealant only; group 2, sealant plus gluma primer; group 3, sealant plus gluma primer and sealer, group 4, sealant plus C & B Metabond. Each tooth had a bonding site prepared for each material by grinding a flat plane on the enamel with 600 grit. The enamel site was etched for 30 seconds, washed for 20 seconds and dried. Each material was mixed according to the instructions of the manufacturer. The sealant (Concise) was placed in a nylon cylinder, light-cured, stored in distilled water for 24 hours, thermocycled (100 cycles at 5 to 55 degrees C) and shear bond strength determined with a knife-edge blade in an Instron running at a crosshead speed of 0.5 mm/min. The results in MPa were: group 1, 11.8 +/- 4.5; group 2, 12.3 +/- 5.0; group 3, 10.3 +/- 1.9; group 4, 12.5 +/- 8.6; and group 5, 15.8 +/- 5.2. Statistically (ANOVA one way) there was no significant difference in the groups.
- Published
- 1991
24. Dentinal shear bond strength, microleakage, and contraction gap of visible light-polymerized liners/bases.
- Author
-
Cooley RL and Barkmeier WW
- Subjects
- Dental Stress Analysis, Humans, Microscopy, Electron, Scanning, Sodium Fluoride, Tensile Strength, Urethane analogs & derivatives, Dental Bonding, Dental Cavity Lining, Dental Leakage, Glass Ionomer Cements
- Abstract
The bond strength and microleakage patterns of three light-curing glass-ionomer cement liners/bases (Vitrebond, XR Ionomer, and Zionomer) were evaluated and compared to a fluoride-releasing resin (TimeLine) designed for the same use. Bond strength tests were performed at 24 hours and 7 days. At 24 hours Vitrebond, Time-Line, and Zionomer had statistically significantly greater bond strengths than XR Ionomer. At 7 days, Vitrebond had a statistically significantly stronger bond than the others. Microleakage was evaluated after 24 hours of thermocycling. Vitrebond and XR Ionomer had statistically significantly less leakage than the others, while TimeLine had significantly more leakage than the others. Polymerization contraction gaps between the liners/bases and dentin were examined with scanning electron microscopy. Contraction gaps were approximately 10 microns with Vitrebond and XR Ionomer and 5 microns with TimeLine. A contraction gap generally was not observed with Zionomer.
- Published
- 1991
25. Fluoride-releasing removable appliances.
- Author
-
Cooley RL and McCourt JW
- Subjects
- Acrylic Resins, Delayed-Action Preparations, In Vitro Techniques, Methylmethacrylates, Time Factors, Fluorides administration & dosage, Glass Ionomer Cements, Orthodontic Appliances, Removable
- Abstract
A method was developed to give removable appliances a fluoride-releasing capability. Visible light-cured glass-ionomer cement inserts were made, placed in resins commonly used for removable appliances, and evaluated for fluoride release over a 2-month period. Fluoride release was measured daily for 7 days, weekly for 4 weeks, and monthly for 1 month. All specimens released fluoride at every time period. There was a "burst effect" in which more fluoride was released the first day, but the amount released decreased significantly on the second day. The amount of fluoride released decreased at each of the daily and weekly measurements, but became relatively stable after 7 days. All specimens were still releasing fluoride at the end of the 2-month test period.
- Published
- 1991
26. Retention of pins in amalgam.
- Author
-
Cooley RL, Marshall TD, and Earnest L
- Subjects
- Dental Amalgam, Titanium, Dental Pins
- Abstract
The Max 021 titanium alloy self-threading retentive pin was evaluated for retention in amalgam and compared to the Link Plus titanium alloy self-threading pin. Fifteen specimens in which amalgam was condensed around the retentive pins were prepared. The specimens were mounted in a specially constructed test apparatus in an Instron Testing Machine and placed under a continuous tensile force (1 mm/min) until failure occurred. The mean force required to induce failure in the Max pin specimens was 87.6 (+/- 37.4) Newtons while the mean for the Link Plus pins was 180.4 (+/- 39.8) Newtons. The failure of the specimens using the Max pins was primarily a result of fracture of the amalgam with removal of the pin intact. The failure site of the Link Plus pin was primarily fracture of the pin itself. Statistically, a significantly greater force was required to induce failure in the Link Plus pins.
- Published
- 1991
27. Evaluation of a 4-META adhesive cement.
- Author
-
Cooley RL, Burger KM, and Chain MC
- Subjects
- Adhesives, Humans, Materials Testing, Methacrylates, Tensile Strength, Boron Compounds, Chromium Alloys, Dental Bonding, Dental Cements, Dentin, Methylmethacrylates
- Abstract
This study investigated the shear bond strength of a new 4-META adhesive cement (C & B-Metabond) to dentin and Ni-Cr-Be alloy (Rexillium III). Fifteen human molar teeth had dentin bonding sites prepared by grinding away the enamel on a water-cooled abrasive wheel to a 600 grit. Fifteen metal alloy specimens were cast, ground to a 600 grit, and air abraded with 50 micron alumina. The 4-META cement was applied to the dentin and metal in accordance with the manufacturer's instructions. After 24 hours in water at 37 degrees C, the shear bond strengths were recorded. The mean bond strength to dentin and the metal alloy was 20.1 megapascals.
- Published
- 1991
- Full Text
- View/download PDF
28. Evaluation of a 4-META porcelain repair system.
- Author
-
Cooley RL, Tseng EY, and Evans JG
- Subjects
- Adhesives, Chromium Alloys, Materials Testing, Tensile Strength, Boron Compounds, Dental Bonding, Dental Cements, Dental Porcelain, Methacrylates, Methylmethacrylates
- Abstract
A recently introduced porcelain repair system utilizing 4-META (Etch-Free Primer with C & B-Metabond) was evaluated for bond strength to porcelain. This system purportedly eliminates hydrofluoric acid-etching and silane pretreatment. Forty porcelain specimens were prepared and treated with the 4-META repair system. A resin cylinder was bonded to the treated porcelain surface. Twenty of the specimens were tested after 24 hours while the other 20 were tested after thermocycling (800 cycles at 6 degrees C to 60 degrees C). The mean bond strengths were: 24 hours 17.4 MPa (+/- 4.8), thermocycled 19.1 MPa (+/- 7). Cohesive failure of the porcelain occurred in all of the specimens, both the 24 hour and the thermocycled. These bond strengths compare favorably with or exceed those of other porcelain repair systems tested in other studies.
- Published
- 1991
- Full Text
- View/download PDF
29. Comparison of wet and dry finishing of resin composites with aluminum oxide discs.
- Author
-
Dodge WW, Dale RA, Cooley RL, and Duke ES
- Subjects
- Aluminum Oxide, Analysis of Variance, Color, Dental Polishing, Hardness, Composite Resins, Dental Restoration, Permanent
- Abstract
Samples of four composites (Herculite, Visio-Dispers, Silux, and Prisma-Fil) were finished with aluminum-oxide discs either wet or dry so that the effects of these two finishing procedures could be compared. The samples were evaluated for surface smoothness, color stability, and surface hardness. Surface smoothness was determined immediately after a sample was finished with a profilometer. Knoop hardness values were determined for each sample immediately after being finished and once a week for five weeks. Color stability was evaluated with a tristimulus colorimeter by the color of each sample being finished and once a week for five weeks. When surface smoothness was compared between the wet- and dry-finished samples, there was no significant difference between Prisma-Fil, Silux, or Herculite; however, the wet-finished Visio-Dispers was significantly rougher than the dry-finished. When surface hardness was compared, there was no significant difference in hardness values between the wet and dry samples when compared over time. When changes in color were evaluated, only Visio-Dispers had no significant change in color for both the wet- and dry-finished samples over the five-week evaluation period. Dry finishing of only one composite (Silux) produced a significant change in color. Dry finishing of composites was superior or equal to wet finishing in all tests except for the color change in Silux.
- Published
- 1991
- Full Text
- View/download PDF
30. Evaluation of a phosphonate BIS-GMA resin as a bracket adhesive.
- Author
-
Rux W, Cooley RL, and Hicks JL
- Subjects
- Acrylic Resins, Bicuspid, Bisphenol A-Glycidyl Methacrylate, Composite Resins, Dental Cements, Humans, Methacrylates, Dental Bonding, Orthodontic Appliances, Phosphates, Resin Cements
- Abstract
Panavia is a modified phosphate ester of dimethacrylate that purportedly forms a strong bond to tooth structure and to metals. The ability of this adhesive to bond orthodontic brackets to enamel was compared to the bond strengths of a no-mix bracket adhesive and a paste/paste autopolymerizing composite resin. Panavia did not form a bond as strong as that achieved by the bracket adhesive but was stronger than the composite resin.
- Published
- 1991
31. Dimensional stability of glass ionomer used as a core material.
- Author
-
Cooley RL, Robbins JW, and Barnwell S
- Subjects
- Analysis of Variance, Cermet Cements, Dental Alloys chemistry, Dental Amalgam chemistry, Gold Alloys, Humans, Pilot Projects, Silver chemistry, Surface Properties, Glass Ionomer Cements chemistry, Post and Core Technique
- Abstract
This laboratory study evaluated the dimensional stability of two reinforced glass ionomers (Ketac-Silver and Fuji Miracle Mix) in comparison with amalgam. Ten core build-ups were prepared with each material on extracted human teeth. Four Minim pins were placed in each tooth for retention. A gold casting was made for each core build-up. The specimens were placed in a distilled water and the distance between the casting and the tooth was measured at 1 hour, 6 hours, and then every 24 hours for 7 days. After 7 days, the measured changes were small, ranging from 1 to 63 microns. The reinforced glass ionomers were found to be dimensionally stable in moisture over a period of 7 days.
- Published
- 1990
- Full Text
- View/download PDF
32. SEM evaluation of etch patterns by three etchants on three porcelains.
- Author
-
al Edris A, al Jabr A, Cooley RL, and Barghi N
- Subjects
- Acidulated Phosphate Fluoride administration & dosage, Acidulated Phosphate Fluoride chemistry, Dental Bonding, Evaluation Studies as Topic, Glass chemistry, Hydrochloric Acid administration & dosage, Hydrofluoric Acid administration & dosage, Microscopy, Electron, Scanning, Nitrates administration & dosage, Sulfuric Acids administration & dosage, Surface Properties, Time Factors, Acid Etching, Dental, Dental Porcelain chemistry, Hydrochloric Acid chemistry, Hydrofluoric Acid chemistry, Nitrates chemistry, Nitric Acid, Sulfuric Acids chemistry
- Abstract
Three etchants (Super Etch, Stripit, and Acidulated Phosphate Fluoride Gel) were evaluated for their ability to create micromechanical retentive areas in three commercial porcelains (Ceramco II, Mirage, and Vita).
- Published
- 1990
- Full Text
- View/download PDF
33. Effect of sterilization on the strength and cutting efficiency of twist drills.
- Author
-
Cooley RL, Marshall TD, Young JM, and Huddleston AM
- Subjects
- Dental Pins, Glutaral adverse effects, Maintenance, Steam adverse effects, Surface Properties, Dental Cavity Preparation instrumentation, Sterilization methods
- Abstract
Retentive-pin twist drills were subjected to four methods of sterilization and then examined to determine possible effects on resistance to fracture, cutting efficiency, and surface condition. Sterilization methods included steam autoclave, chemical vapor autoclave, dry heat, and immersion in glutaraldehyde. Although the steam and chemical vapor groups had lower mean fracture strengths after sterilization, there was no statistically significant difference among the groups. Only the steam autoclave group showed a statistically significant loss of cutting efficiency. Scanning electron microscopic evaluation revealed that only drills sterilized by steam autoclave showed changes in the surface condition or cutting edges.
- Published
- 1990
34. Microleakage of five temporary endodontic restorative materials.
- Author
-
Hagemeier MK, Cooley RL, and Hicks JL
- Subjects
- Calcium Sulfate, Cermet Cements, Dental Alloys, Dental Cements, Drug Combinations, Glass Ionomer Cements, Humans, Methacrylates, Molar, Polyvinyls, Root Canal Obturation, Zinc Oxide, Dental Leakage prevention & control, Dental Restoration, Temporary, Root Canal Filling Materials
- Abstract
This study evaluated the ability of five interim endodontic restorative materials to resist microleakage. Sixty extracted human molars were prepared for initial endodontic therapy via occlusal access preparations. After removal of the pulpal tissue, a cotton pellet was placed in the pulp chamber. The access preparations were sealed with one of the following materials or combinations: TERM, Cavit, IRM, Ketac-Silver, or a IRM-Cavit "sandwich" restoration. The specimens were thermocycled for 24 hours (800 cycles), immersed in methylene blue dye for 4 hours, sectioned, and evaluated under a microscope for microleakage. TERM, Cavit, and the IRM-Cavit "sandwich" had virtually no microleakage, while Ketac-Silver and IRM exhibited gross microleakage.
- Published
- 1990
- Full Text
- View/download PDF
35. Fluoride release from light-cure liners/bases: an eight-month report.
- Author
-
Cooley RL and McCourt JW
- Subjects
- Acrylic Resins, Glass Ionomer Cements, Humans, Hydroxyapatites, Maleates, Silicon Dioxide, Dental Cavity Lining, Fluorides, Topical administration & dosage
- Abstract
Five new visible light-cure cavity liners/bases that contain fluoride were evaluated for fluoride release over an 8-month period. Fluoride was released from all the materials but decreased significantly over the test period. There was also a significant difference in the amount of fluoride released between the materials. At 8 months, only XR Ionomer and Vitrabond were releasing detectable fluoride, with XR Ionomer releasing significantly more.
- Published
- 1990
- Full Text
- View/download PDF
36. Evaluation of a fluoride-containing sealant by SEM, microleakage, and fluoride release.
- Author
-
Cooley RL, McCourt JW, Huddleston AM, and Casmedes HP
- Subjects
- Drug Evaluation, Humans, Microscopy, Electron, Scanning, Molar, Dental Leakage prevention & control, Fluorides administration & dosage, Pit and Fissure Sealants
- Abstract
A fluoride-containing sealant (FluroShield) was evaluated in vitro and compared to a sealant without fluoride (Helio-Seal). Both materials were applied to the occlusal surface of extracted teeth and microscopically evaluated for their ability to penetrate pits and fissures. Additional specimens were subjected to dye immersion and evaluated for resistance to microleakage. Disc-shaped samples of the fluoride-containing sealant were immersed in distilled water and analyzed daily for seven days for fluoride release. All specimens of FluroShield released fluoride during the evaluation period, but there were differences between the materials in resistance to microleakage.
- Published
- 1990
37. Evaluation of air-powder abrasive prophylaxis units.
- Author
-
Cooley RL, Brown FH, and Lubow RM
- Subjects
- Bicarbonates, Equipment Design, Humans, Sodium, Sodium Bicarbonate, Dental Prophylaxis instrumentation
- Published
- 1990
38. Fluoride release from fluoride-containing liners/bases.
- Author
-
McCourt JW, Cooley RL, and Huddleston AM
- Subjects
- Dental Cavity Lining, Fluorides administration & dosage
- Abstract
Five new visible light-curing cavity liners/bascs that contain fluoride were evaluated for fluoride release over a 17-week period. Fluoride was released from all the materials, but the level of fluoride release decreased significantly (P less than .01) over the test period. There was also a statistically significant (P less than .05) difference among the materials in the amount of fluoride released.
- Published
- 1990
39. Fracture resistance of reinforced glass ionomer as a buildup material.
- Author
-
Robbins JW, Cooley RL, and Barnwell S
- Subjects
- Dental Amalgam, Dental Stress Analysis, Humans, Dental Cements, Glass Ionomer Cements
- Abstract
This study in vitro investigated the fracture resistance of two reinforced glass ionomers and amalgam when used as core-buildup materials. Four-pin buildups using the three materials were placed in human molar teeth and prepared for gold crowns. The crowns were cemented and the teeth were compressed at 45 degrees to failure. There was no significant difference found in the fracture resistance of the three materials.
- Published
- 1990
40. Reactions to local anesthetic solutions--true allergy or not.
- Author
-
Cooley RL
- Subjects
- Adult, Anesthesia, Dental adverse effects, Humans, Male, Anesthetics, Local adverse effects, Drug Hypersensitivity prevention & control
- Published
- 1979
41. Surgical retraction for subgingival Class V restorations.
- Author
-
Lubow RM and Cooley RL
- Subjects
- Adult, Bacteria isolation & purification, Gingiva microbiology, Humans, Dental Caries therapy, Dental Restoration, Permanent methods, Gingiva anatomy & histology
- Published
- 1985
42. Temperature change caused by reducing pins in dentin.
- Author
-
Barkmeier WW and Cooley RL
- Subjects
- Air, Dental Instruments, Dental Pulp physiology, Humans, Thermometers, Water, Dental High-Speed Technique instrumentation, Dental Pins, Dentin physiology, Hot Temperature
- Abstract
Pin temperature increases (heat generation) was prevented by an air-water coolant. Pin height adjustment with an ultraspeed instrument using air-water coolant produces no potentially injurious heat generation.
- Published
- 1979
- Full Text
- View/download PDF
43. Microleakage of Ketac-Silver in the tunnel preparation.
- Author
-
Robbins JW and Cooley RL
- Subjects
- Humans, Silver, Dental Cements, Dental Leakage, Dental Restoration, Permanent, Glass Ionomer Cements
- Published
- 1988
44. AIDS: an occupational hazard?
- Author
-
Cooley RL and Lubow RM
- Subjects
- Acquired Immunodeficiency Syndrome etiology, Acquired Immunodeficiency Syndrome immunology, Acquired Immunodeficiency Syndrome transmission, Female, Humans, Male, Occupational Diseases etiology, Occupational Diseases transmission, Acquired Immunodeficiency Syndrome pathology, Dentists, Occupational Diseases pathology
- Published
- 1983
- Full Text
- View/download PDF
45. Root amputation of a bridge abutment.
- Author
-
Lubow RM and Cooley RL
- Subjects
- Denture, Partial, Fixed, Humans, Male, Middle Aged, Apicoectomy, Dental Abutments, Periodontal Pocket surgery, Periodontitis surgery
- Published
- 1981
46. Evaluation of potassium oxalate as a cavity liner.
- Author
-
Sandoval VA, Cooley RL, and Barnwell SE
- Subjects
- Composite Resins, Dental Amalgam, Dental Bonding, Dental Materials, Dental Restoration, Permanent, Humans, Methylene Blue, Organic Chemicals, Resins, Plant, Dental Cavity Lining, Dental Leakage prevention & control, Oxalates
- Abstract
All dental restoratives exhibit some microleakage. Recent studies disclosed that oxalate salts were superior to Copalite varnish in reducing dentinal permeability, but inferior in reducing microleakage. This study compared the effectiveness of a potassium oxalate solution (DDS) with three other cavity liners (Copalite, Cavi-Line, Prisma Universal Bond) and a no-liner control in reducing microleakage under amalgam restorations. Under the conditions of this study, DDS solution was significantly effective in reducing microleakage under amalgam restorations.
- Published
- 1989
- Full Text
- View/download PDF
47. Safe storage of amalgam scrap.
- Author
-
Barkmeier WW and Cooley RL
- Subjects
- Drug Storage, Mercury Poisoning prevention & control, Dental Amalgam standards
- Published
- 1980
48. Effect of air-powder abrasive on glass ionomer microleakage.
- Author
-
Cooley RL and Lubow RM
- Subjects
- Humans, Dental Cements, Dental Leakage etiology, Dental Prophylaxis, Glass Ionomer Cements
- Published
- 1989
49. The two-in-one, self-threading, self-shearing pin: efficacy of insertion techniques.
- Author
-
Barkmeier WW, Frost DE, and Cooley RL
- Subjects
- Dental Restoration, Permanent methods, Dental Stress Analysis, Stress, Mechanical, Dental Pins
- Abstract
An in vitro study has shown that the TMS minim two-in-one, self-shearing pin reaches maximum depth in a 2-mm pin channel before shearing off with insertion by a hand-turned wrench. The self-shearing, two-in-one pin did not achieve the full channel depth of 2 mm with insertion by an Auto Klutch handpiece.
- Published
- 1978
- Full Text
- View/download PDF
50. Anterior tooth movement as an adjunct to fixed prosthodontics.
- Author
-
Cooley RL, Lubow RM, and Hornbeck D
- Subjects
- Adult, Humans, Male, Orthodontic Appliances, Removable, Denture, Partial, Fixed, Diastema therapy, Tooth Movement Techniques methods
- Published
- 1982
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.