bluuebunny/crossref_metadata_2025_split huggingface dataset:
Retention of Cemented Implant‐Supported Restorations
Authors: Kent Dennis K. , Koka Sreenivas , Froeschle Mary Lynn 
Published: March 2005

Purpose This investigation compared cement failure loads of a gold cylinder luted to a CeraOne titanium abutment (5‐mm‐high chimney) 24 hours postcementation when either zinc phosphate, Tempbond NE, or Tempbond luting agent was used.Materials and Methods Luting agent (0.01 mL) was applied to the internal aspect of the gold cylinder, and the cylinder was seated with finger pressure followed by a load of 5 kg for 10 minutes. The specimens were stored in 100% humidity at 37°C for 24 hours before a uniaxial tensile force was applied to the gold cylinder by a mechanical testing instrument. A load‐displacement chart was plotted and the cement failure load (CFL) calculated in kilograms. CFLs were determined for each luting agent with the access opening for the CeraOne gold screw on the internal of the abutment either unfilled or filled with autopolymerizing resin.Results A two‐way ANOVA and Tukey's HSD revealed that zinc phosphate resulted in significantly higher (p < .05) mean CFLs than Tempbond or Tempbond NE. In general, filling the access opening did not affect mean CFLs for zinc phosphate and Tempbond NE. However, mean CFLs for gold cylinders cemented with Tempbond and a filled access opening were significantly higher than mean CFLs with an unfilled access opening. However, neither the filled nor the unfilled Tempbond group mean CFL was significantly different from either Tempbond NE mean CFL.Conclusions Twenty‐four hours postcementation, zinc phosphate luting cement significantly enhanced CFLs of a CeraOne gold cylinder luted to a 5‐mm CeraOne titanium abutment compared with Tempbond and Tempbond NE. Filling the gold screw access opening of the abutment with autopolymerizing resin only led to higher mean CFLs when Tempbond was used as the luting agent. Filling the access opening had no effect (p > .05) on mean CFLs when Tempbond NE or zinc phosphate was used.
Effectiveness of Adhesive Systems for a Co–Cr Removable Partial Denture Alloy
Authors: NaBadalung Darunee P. , Powers John M. 
Published: March 2005

Purpose In vitro bond strengths of traditional denture base acrylic resin (Lucitone 199) to a cobalt‐chromium partial denture alloy (J.D. Partial Denture Alloy) were tested using two surface pretreatments (sandblast, sandblast and electrochemical etch) with three adhesive primers: Lee Metal Primer, Acrylic Solder, and CR Inlay cement. A sandblasted group with no primer served as the control.Materials and Methods The alloy specimens (8.0‐mm bonding diameter) were cast and invested to receive a traditional denture base resin after surface treatments (sandblasted, and sandblasted‐electrochemically etched) and application of adhesive primers. The bonded specimens were stored in distilled water at 37°C for 24 hours and divided into two groups. The first group was debonded in tension on a testing machine at a cross‐head speed of 0.05 cm/min. The second group was subjected to thermocycling of 1,000 cycles and then tested for tensile bond strength. The force at which the bond failed was recorded, and the bond strength was calculated in megapascals (MPa). The sites of bond failure were examined, quantified under (20x) magnification, and recorded. Ten specimens were evaluated for each experimental condition for a total of 160 specimens. Data were analyzed by ANOVA with a factorial design. Means were compared by Tukey intervals at the 0.05 significance level.Results Significant differences in bond strength were observed, with primers being the most important factor, followed by pretreatment and storage and thermocycling with significant interactions. Sandblasted‐electrochemically etched alloy with primers more effectively enhanced bond strength of the denture base resin to the treated alloy than sandblasted alloy with primers. Thermocycling had a greater effect on bond strength of the specimens with Acrylic Solder when compared with Lee and CR Inlay primers. The highest bond strengths (>18.0 MPa) were observed for the conditions involving electrochemical etching and the priming with CR Inlay cement (both after 24 hours and thermocycling of 1,000 cycles). For primed specimens, the bond failures occurred cohesively within the primers or the denture resin and adhesively between the primers and the denture base resin, or between primers and alloy. For nonprimed, the bond failures occurred adhesively at the denture base resin‐metal interface.Conclusions Nonprimed specimens (both sandblasted and electrochemically etched) had lowest bond strength (0.4 ± 0.1 MPa; 0.3 ± 0.4 MPa). The bond strengths of the primed treated specimens were improved significantly. The CR Inlay‐treated specimens exhibited the highest bond strength (20.6 ± 6.3 MPa). After thermocycling for 1,000 cycles, the bond strengths of the specimens were significantly lower than the bond strengths of the specimens after 24 hours.
A Review of Preweighed, Packaged Die Stone Versus Bulk Die Stone Use in a Dental School
Authors: Price Richard B. T. , Doyle M. Gorman , Bannerman Ronald A. 
Published: March 2005

Purpose This study compared the quantity of preweighed, packaged die stone use to bulk die stone use by dental students.Materials and Methods Starting in September 1994, all the bulk die stone was removed from the dental clinic, and only preweighed packages of die stone (Silky‐Rock, Whip Mix) were available to students. At the end of August 1995 and August 1997, the amount of preweighed die stone used by the students was determined and compared with the amount of bulk die stone (DieKeen, Modern Materials) used during the period of September 1993 to August 1994.Results Between September 1994 and August 1997, the students used 42% less per annum of the preweighed, packaged die stone than the previous annual use of bulk die stone. The laboratories were much cleaner when the preweighed packages were used, and fewer cleaning staff were required. The environment was also cleaner for the laboratory staff, who used to fill the bulk containers with gypsum products.Conclusions Students used 42% less die stone per annum when using the preweighed packages.
Marginal Adaptation of Implant‐Supported Metal‐Ceramic Crowns Fabricated With Gold Cylinders
Authors: Sutherland J. Kenneth , Ritsco Ronald G. , Budd Scott R. 
Published: March 2005

Purpose The purpose of this investigation was to determine the mean marginal discrepancy of metal‐ceramic crowns fabricated with gold cylinders and cemented on implant abutments. These discrepancies were then compared with those measured previously for implant‐supported ceramic crowns.Materials and Methods Fifteen Nobel BioCare CeraOne abutments were connected to implant fixtures embedded in acrylic resin blocks. Marginal discrepancies were determined for gold cylinders, gold cylinders plus ceramic alloy (metal frameworks), completed metal‐ceramic crowns, and cemented metal‐ceramic crowns using a stereomicroscope equipped with a video camera linked to a computer. A Hotelling's T2 test (p .05) was used to evaluate potential differences in mean marginal discrepancies among groups.Results The mean marginal discrepancies were: 1) gold cylinders, 7.56 ± 2.73 μm; 2) metal frameworks, 6.21 ± 1.34 μm; 3) metal‐ceramic crowns, 11.06 ± 3.21 μm; and 4) zinc‐phosphate cemented crowns, 31.47 ± 6.65 μm. No significant difference between gold cylinders and metal frameworks was found. Mean marginal discrepancies for metal‐ceramic crowns were significantly greater than discrepancies for cast gold cylinders. Cemented‐crown mean marginal discrepancy was significantly greater than all other means.Conclusions Cemented metal‐ceramic crowns fabricated using proprietary gold cylinders exhibited well‐fitting margins (31.47 μm).
Tear Strength of Four Irreversible Hydrocolloid Impression Materials
Authors: Cohen Brett I. , Pagnillo Mark K. , Lee Musikant Barry , Deutsch Allan S. 
Published: March 2005

Purpose The purpose of this investigation was to examine the tear strength of four irreversible hydrocolloid (alginate) impression materials (Tare‐Free Alg, Jeltrate, Identic, and Kromopan).Materials and Methods Eighty specimens, 20 for each alginate tested, were according to the manufacturers' instructions. A cutting die described in American Standard Test and Material document D‐1004‐94a was used to prepare test specimens. Immediately after removal from the cutting die, test specimens were measured at five points with an electronic caliper. Test specimens were placed into a specialized jig, and a Shimpo force gauge was used to measure tear strength. The tear test was performed no more than 10 minutes after mixing the alginate material with water. The tear strength was then calculated. One‐way ANOVA was used to compare the mean force required to induce tearing for each of the four groups, followed by the Newman‐Keuls pairwise multiple comparisons test.Results Results were considered statistically significant at p < .05. There was a statistically significant difference between alginate materials (p < .0001). The Newman‐Keuls multiple comparisons procedure showed that Tare‐Free Alg (514.5 g/cm) had a significantly higher tear strength value (p < .0001) than Jeltrate (259.0 g/cm), Identic (289.9 g/cm), and Kromopan (323.9 g/cm).Conclusions Tara‐Free Alg had the highest tear strength value, followed by Jeltrate, Identic, and Kromopan.
Comparison of Perceptions of Computer‐Animated Left‐ and Right‐Facing Profiles
Authors: Anderson Nina K. , Evans Carla A. , Giddon Donald B. 
Published: March 2005

PurposeAlthough scientific publications differ in displaying left‐ or right‐facing profiles, there are few systematic studies of the possible effects of directional biases and laterality on patients' and clinicians' perceptions of treatment need, outcomes, and satisfaction. As part of a research program to quantitate the physical bases of the perceived zone of acceptability and most‐pleasing facial profiles, responses to computer‐animated left‐ and right‐facing soft‐tissue profile images were compared and related to eye and hand preference.Materials and MethodsStandardized left‐facing, soft‐tissue profile images were captured in color and digitized. The right‐facing profile was created by reversing the left profile image to display a mirror image. Using imaging and customized morphing software, retrusive and protrusive extremes were created, from which transitional frames were developed to display five features of the soft‐tissue profile: upper lip, chin, bimaxillary position, lower face height, and mandible. One left‐ and one right‐facing profile for a Class II division 1 female, and Class III male were randomly presented to 24 subjects who were asked to indicate: 1) acceptability by pressing a mouse button and releasing the button when the images were no longer acceptable; and 2) most‐pleasing image by pressing the mouse button once.ResultsNo differences were found between left‐ and right‐profile images for zone of acceptability, midpoint of the zone of acceptability, or most pleasing; nor was there any relation to laterality measures. However, consistently higher intercorrelations among the features for the zone of acceptability were found for the left‐ than for the right‐facing profiles for retrusive to protrusive and protrusive to retrusive excursions measured in millimeters (p < .001). The bimaxillary position accounted for most of the variance in judgments of acceptability with greater influence on the left than on the right profile.ConclusionWith the increasing use of computer‐imaging in dental practices, the influence of psychophysical and other environmental variables on perception must be considered.
Distortion of Three‐Unit Implant Frameworks During Casting, Soldering, and Simulated Porcelain Firings
Authors: Zervas Photios J. , Papazoglou Efstratios , Beck F. Michael , Carr Alan B. 
Published: March 2005

PurposeThe aim of this study was to assess distortion inherent in casting, soldering, and simulated porcelain firings of screw‐retained, implant‐supported three‐unit fixed partial dentures (FPDs).Materials and MethodsTen wax patterns were fabricated on a die‐stone cast containing two implants, 20 mm apart from center to center. Five specimens were cast in a high‐palladium alloy, exposed to simulated porcelain firings, sectioned, and then soldered with low‐fusing solder. Five specimens were cast, sectioned, soldered with high‐fusing solder, and then exposed to simulated porcelain firings. For each specimen, two horizontal and six vertical distances between appropriately scribed reference points were measured with a traveling microscope. Comparisons were made among the various measurements taken after wax‐pattern fabrication, casting, high‐ and low‐fusing soldering, and each porcelain firing. Data were analyzed using a repeated‐measures factorial ANOVA (α= 0.05).ResultsSignificant difference was detected in the amount of horizontal distortion during casting (53 ± 24 μm) and high‐fusing soldering (−49 ± 50 μm), as well as in the amount of horizontal distortion during high‐fusing soldering (−49 ± 50 μm) and low‐fusing soldering (17 ± 26 μm). However, no clinically significant difference was found in the amount of horizontal distortion during casting, low‐fusing, and high‐fusing soldering. The greatest amount of distortion during the simulated porcelain firings took place during the oxidizing cycle.ConclusionsSoldering did not improve the casting misfit of a three‐unit implant‐retained FPD model. Metal‐ceramic implant frameworks should be oxidized before intraoral fit evaluation.
Vertical Height Loss: An Investigation of Four Restorative Materials Opposing Enamel
Authors: Ramp Merrie H. , Ramp Lance C. , Suzuki Shiro 
Published: March 2005

PurposeThe objective of this in vitro investigation was to compare the vertical wear produced by cone‐shaped styli of three ceramic restorative materials and a Type III gold alloy opposing flattened human enamel. Vertical wear was measured as enamel height loss, material stylus height loss, and total vertical height loss (the sum of the enamel height loss and the restorative material height loss).Materials and MethodsTen cone‐shaped styli were fabricated from each of four restorative materials, which included two machined ceramics, a pressed ceramic, and a Type III gold alloy. To maintain the standardized shape, styli were not polished or glazed. Specimens were subjected to wear in the presence of water for 100,000 cycles at 1.2 Hz under a load of 75 N using a wear simulation device. Enamel wear was evaluated by profilometry, and stylus wear was evaluated by computer imaging. Vertical wear was reported as enamel height loss, material stylus height loss, and total vertical height loss (the sum of the enamel height loss and material height loss). Data were compared using one‐way analysis of variance and Scheffe's analysis (α= 0.05).ResultsSignificant differences existed among materials based on material height loss (p= .0001), enamel height loss (p= .0001), and total vertical height loss (p= .0118). No significant difference among the three ceramics was found in mean total height loss, which ranged from 0.280 to 0.305 mm. However, the Type III gold exhibited less mean total wear (0.231 ± 0.082) than the pressed and one machineable ceramic. This machined ceramic exhibited the most material height loss (0.249 ± 0.044 mm). With the other ceramics, mean enamel wear was significantly more (0.211 and 0.216 mm, respectively).ConclusionsDuring wear simulation, pressed or machineable ceramics opposing flattened enamel exhibited a similar degree of total vertical height loss. One machined ceramic material wore significantly more than the other materials. The other machineable ceramic and the pressed ceramic wore the opposing enamel significantly more.
Comparative Genomic Hybridizations ofEntamoebaStrains Reveal Unique Genetic Fingerprints That Correlate with Virulence
Authors: Shah Preetam H. , MacFarlane Ryan C. , Bhattacharya Dhruva , Matese John C. , Demeter Janos , Stroup Suzanne E. , Singh Upinder 
Published: March 2005

ABSTRACTVariable phenotypes have been identified forEntamoebaspecies.Entamoeba histolyticais invasive and causes colitis and liver abscesses but only in ∼10% of infected individuals; 90% remain asymptomatically colonized.Entamoeba dispar, a closely related species, is avirulent. To determine the extent of genetic diversity amongEntamoebaisolates and potential genotype-phenotype correlations, we have developed anE. histolyticagenomic DNA microarray and used it to genotype strains ofE. histolyticaandE. dispar. On the basis of the identification of divergent genetic loci, all strains had unique genetic fingerprints. Comparison of divergent genetic regions allowed us to distinguish betweenE. histolyticaandE.dispar, identify novel genetic regions usable for strain and species typing, and identify a number of genes restricted to virulent strains. Among the fourE. histolyticastrains, a strain with attenuated virulence was the most divergent and phylogenetically distinct strain, raising the intriguing possibility that genetic subtypes ofE. histolyticamay be partially responsible for the observed variability in clinical outcomes. This microarray-based genotyping assay can readily be applied to the study ofE. histolyticaclinical isolates to determine genetic diversity and potential genotypic-phenotypic associations.
Detection of and Response to Signals Involved in Host-Microbe Interactions by Plant-Associated Bacteria
Authors: Brencic Anja , Winans Stephen C. 
Published: March 2005

SUMMARYDiverse interactions between hosts and microbes are initiated by the detection of host-released chemical signals. Detection of these signals leads to altered patterns of gene expression that culminate in specific and adaptive changes in bacterial physiology that are required for these associations. This concept was first demonstrated for the members of the familyRhizobiaceaeand was later found to apply to many other plant-associated bacteria as well as to microbes that colonize human and animal hosts. The familyRhizobiaceaeincludes various genera of rhizobia as well as species ofAgrobacterium. Rhizobia are symbionts of legumes, which fix nitrogen within root nodules, whileAgrobacterium tumefaciensis a pathogen that causes crown gall tumors on a wide variety of plants. The plant-released signals that are recognized by these bacteria are low-molecular-weight, diffusible molecules and are detected by the bacteria through specific receptor proteins. Similar phenomena are observed with other plant pathogens, includingPseudomonas syringae, Ralstonia solanacearum, andErwiniaspp., although here the signals and signal receptors are not as well defined. In some cases, nutritional conditions such as iron limitation or the lack of nitrogen sources seem to provide a significant cue. While much has been learned about the process of host detection over the past 20 years, our knowledge is far from being complete. The complex nature of the plant-microbe interactions makes it extremely challenging to gain a comprehensive picture of host detection in natural environments, and thus many signals and signal recognition systems remain to be described.
Ankle plantar flexor force production is an important determinant of the preferred walk-to-run transition speed
Authors: Neptune Richard R. , Sasaki Kotaro 
Published: March 2005

SUMMARY
The mechanisms that govern the voluntary transition from walking to running as walking speed increases in human gait are not well understood. The objective of this study was to examine the hypothesis that plantar flexor muscle force production is greatly impaired at the preferred transition speed(PTS) due to intrinsic muscle properties and, thus, serves as a determinant for the walk-to-run transition. The plantar flexors have been shown to be important contributors to satisfying the mechanical energetic demands of walking and are the primary contributors to the observed ground reaction forces (GRFs) during the propulsion phase. Thus, if the plantar flexor force production begins to diminish near the PTS despite an increase in muscle activation, then a corresponding decrease in the GRFs during the propulsion phase would be expected. This expectation was supported. Both the peak anterior/posterior and vertical GRFs decreased during the propulsion phase at walking speeds near the PTS. A similar decrease was not observed during the braking phase. Further analysis using forward dynamics simulations of walking at increasing speeds and running at the PTS revealed that all lower extremity muscle forces increased with walking speed, except the ankle plantar flexors. Despite an increase in muscle activation with walking speed, the gastrocnemius muscle force decreased with increasing speed, and the soleus force decreased for walking speeds exceeding 80% PTS. These decreases in force production were attributed to the intrinsic force–length–velocity properties of muscle. In addition, the running simulation analysis revealed that the plantar flexor forces nearly doubled for similar activation levels when the gait switched to a run at the PTS due to improved contractile conditions. These results suggest the plantar flexors may serve as an important determinant for the walk-to-run transition and highlight the important role intrinsic muscle properties play in determining the specific neuromotor strategies used in human locomotion.
Effect of ultrasound-guided interstitial laser photocoagulation on benign solitary solid cold thyroid nodules – a randomised study
Authors: Døssing Helle , Bennedbæk Finn Noe , Hegedüs Laszlo 
Published: March 2005

Aim: To evaluate the efficacy of ultrasound (US)-guided interstitial laser photocoagulation (ILP) on thyroid function, nodule size and patient satisfaction in benign solitary solid cold thyroid nodules by comparing one ILP session with no treatment in a prospective randomised study.
Materials and methods: Thirty euthyroid outpatients with a benign solitary solid and a scintigraphically cold thyroid nodule causing local discomfort were assigned to one session of ILP (n = 15) or observation (n = 15) and followed for 6 months. Thyroid nodule volume and total thyroid volume were assessed by US and thyroid function was determined by routine assays before and during follow-up. Pressure and cosmetic complaints before and at 6 months were evaluated on a visual analogue scale. ILP was performed under US guidance and with an output power of 2.5–3.5 W.
Results: In the ILP group, the nodule volume decreased from 8.2 ml (6.1; 11.9) (median; quartiles) to 4.8 ml (3.0; 6.6) after 6 months (P = 0.001). The overall median reduction was 44% (37; 52), which correlated with a significant decrease in pressure symptoms as well as cosmetic complaints. In the control group, a non-significant increase in median nodule volume of 7% (0; 34) after 6 months was seen. No major side-effects were seen in the ILP group. There was no correlation between thermal energy deposition and nodule volume reduction. Thyroid function was unaltered throughout.
Conclusion: US-guided ILP, given as a single treatment, resulted in a satisfactory clinical response in the majority of patients with a benign solitary solid cold thyroid nodule, and may become a clinically relevant alternative to surgery in selected patients.
Modification of Electrical Properties and Magnetic Domain Structures in Magnetic Nanostructures by AFM Nanolithography
Authors: Takemura Y. , Shirakashi J.‐I. 
Published: March 2005

AbstractNanolithography techniques using a scanning probe microscopy have recently attracted much attention. Here, the fabrication of magnetic nanostructures, and modification of their electrical and magnetic properties are introduced. Advantages of lateral structures for magnetic devices fabricated by the nanolithography using an atomic force microscopy are discussed. In order to develop these spin‐related devices, control of magnetic domains in nanoscale ferromagnetic materials is significant. Experimental results on the direct modification of magnetic domain structures in Co nanostructures by the nanolithography are lastly described.