bluuebunny/crossref_metadata_2025_split huggingface dataset:
Textural Properties of Food Used in Studies of Mastication
Authors: Wang J.-S. , Stohler C.S. 
Published: November 2010

Foods are known to influence jaw elevator muscle activity in chewing. With the long-range goal of gaining insight into force control and modeling muscle recruitment, these initial experiments were performed to determine the textural properties of commonly used test food. Experiments were carried out by means of a standard Instron instrument, equipped with a compression cell. A stylus with 45-degree cuspal angulation and an opposing copper-plated lower arch was used for approximation of the natural situation. The breakage force characteristics of a single peanut, a carrot cube, beefstick, and monkey chow were determined. The peanut demonstrated the steepest and beefstick the least steep force build-up, with breaking forces of 104 N (Newtons) for monkey chow, 66 N for the carrot, and 52 N for the peanut. No clear breakage point was found with beefstick; the force build-up showed an initial plateau at 25 N, which was followed by a significantly steeper force increase to peak. We conclude that each of the test foods commonly used in studies of mastication had particular breakage characteristics in terms of its force-time curve.
An Analysis of Clinical Studies on Resin-bonded Bridges
Authors: Creugers N.H.J. , Van 't Hof M.A. 
Published: November 2010

Many clinical data on resin-bonded bridges (RBBs) have been published in the last ten years. The survival rates vary widely, and the conclusions are sometimes conflicting. A method of combining the results of different studies in order to draw conclusions about the effectiveness of therapeutic concepts is meta-analysis. The aims of the meta-analysis in this study were: (1) to assess an "overall" survival ratio for RBBs and (2) to explore relationships between potential success factors and reported survival times. About 60 publications with clinical data on RBBs were reviewed. Following a number of inclusion criteria (information adequate to calculate or assess survival rates, as well as adequate information about the patients, the designs, and types of RBBs), 16 different samples were used for this meta-analysis. A weighted multiple-regression analysis revealed no significant effects of "type of retention" and "location" on the survival percentages. Kaplan-Meier estimates were used to assess overall survival in a secondary analysis with the data from all 16 samples (n = 1598). The overall survivals were: one year, 89 ± 1%; two years, 84 ± 1%; three years, 80 ± 1%; and four years, 74 ± 2%.
Immunohistochemical Localization of Types I, V, and VI Collagen in Human Permanent Teeth and Periodontal Ligament
Authors: Lukinmaa P.-L. , Waltimo J. 
Published: November 2010

Types I, V, and VI collagen were immunohistochemically localized in frozen and paraffin sections of human permanent teeth, periodontal ligament, and alveolar bone, by means of polyclonal antibodies. Hyaluronidase was effective in exposing epitopes of the various collagen types. The expression of type I collagen in predentin was strong in frozen sections, whereas the dental pulp stained relatively weakly. Staining intensity in the dentin matrix decreased toward enamel and cementum. Reactivity in the periodontal ligament was moderate, and it was weaker in the alveolar bone and also in cementum, which stained more intensely in paraffin sections. Staining for type V collagen was strong in the pulp. Weak reactivity in predentin became uniformly evident in frozen sections only, and dentin was negative. The periodontal ligament stained with moderate intensity, and a weak staining reaction was seen in cementum and bone. Staining for type VI collagen in the pulp and periodontal ligament was strong, whereas predentin and dentin were negative. The alveolar bone stained moderately, and non-uniform reactivity was present in cementum. In non-mineralized dental tissues, the use of frozen material enabled good immunohistochemical localization of the distinct collagen types to be carried out. Their distribution patterns in dental tissues not only differed, but the relative staining intensities for each collagen type in the pulp and predentin were inversely related. However, differences may exist in the exposure of the epitopes of collagen(s) between soft and mineralized tissues.
Measurement of Water Sorption by Resin Composite Adhesives with Near-Infrared Spectroscopy
Authors: Diaz-Arnold A.M. , Arnold M.A. , Williams V.D. 
Published: November 2010

Spectroscopic methodology was used to follow the water uptake of disks of two resin composite luting agents during long-term storage. Fourier-transform near-infrared (FT-NIR) spectroscopy was used for collection of spectra over the 4200-6500 cm -1 spectral region. The 5200-cm-1 absorption band of water was monitored initially, at 24 h, seven days, two weeks, and then monthly over a period of 12 months. The disks were stored in water, air, and desiccated conditions. Disks were also subjected to two alternate cycles (two weeks each) of hydration and desiccation. A spectral manipulation program was used for quantitation of the area under the water absorbance band. Area ratios demonstrated similar water-uptake patterns for the two adhesives. Rapid water uptake was seen within the first two weeks of storage. Alternate hydration and desiccation of the samples showed that water uptake by the filler/polymer network was partially reversible. The desiccant was unable to remove all the water from the samples, which indicated that some water was tightly held within the sample matrix. FT-NIR spectroscopy is recommended as an effective method for study of the equilibration of resin composites in water.
Delivery of Antiplaque Agents from Dentifrices, Gels, and Mouthwashes
Authors: Cummins D. , Creeth J.E. 
Published: November 2010

Antiplaque agents delivered from toothpastes, gels, or mouthrinses can augment mechanical oral hygiene procedures to control the formation of supragingival plaque and the development of early periodontal disease. Clinically effective antiplaque agents are characterized by a combination of intrinsic antibacterial activity and good oral retention properties. The overall oral retention of an antiplaque agent is determined by the strength and rate of association of the agent with its receptor sites and the accessibility of these sites. The substantivity of an antiplaque agent and its clearance from the oral cavity are determined by the rate of dissociation of the agent from the receptor sites and the salivary composition and flow rate. Positively charged and non-charged organic molecules, metal ions, enzymes, and surface-active agents have all been considered as antiplaque agents. To exert clinical antiplaque activity, an antimicrobial agent must be formulated in a chemically compatible delivery vehicle to give optimal release and uptake to the sites of action in a biologically active form during its time of application. In principle, antiplaque activity may be enhanced by combining antimicrobial agents with broadly similar, but complementary, modes of action. Alternatively, the activity of a single agent may be increased by use of a retention aid to enhance oral substantivity. Substantial evidence exists to demonstrate the validity of the first approach. However, there are few data, as yet, to support the effectiveness of the second. The oral mucosa is the bulk retention site for all clinically proven antiplaque agents. Plaque, the pellicle-coated tooth surface, and saliva are probably all sites of biological action. A detailed understanding of the interactions between agents and the various receptor sites, and of the importance of these receptor sites to biological activity, is generally lacking.
Adsorption of Human Salivary Proteins to Hydroxyapatite: A Comparison Between Whole Saliva and Glandular Salivary Secretions
Authors: Jensen J.L. , Lamkin M.S. , Oppenheim F.G. 
Published: November 2010

The protein compositions of in vitro pellicles formed from whole saliva and parotid and submandibular secretions were determined by use of synthetic hydroxyapatite as a model for dental enamel. The adsorbed and unadsorbed protein fractions were analyzed by amino acid analysis and both anionic and cationic discontinuous polyacrylamide gel electrophoresis. For further characterization of the in vitro pellicle, the adsorbed fractions were subjected to gel filtration on Sephadex G-100 and reversed-phase chromatography on C18 columns. Amylase, acidic and glycosylated proline-rich proteins, statherins, and histatins were identified in the parotid-derived pellicle. Detailed analysis of the statherin-containing fractions resulted in the observation of several statherin-like proteins. The use of cationic gel electrophoresis allowed for the identification of histatin 3 and histatin 5, which have not been previously detected in pellicle formed in vitro. The protein composition of submandibular-derived pellicle was similar to that of parotid-derived pellicle except for the presence of cystatins and the absence of glycosylated proline-rich proteins. In contrast, in vitro pellicle derived from whole saliva exhibited a vastly different composition, consisting primarily of amylase, acidic proline-rich proteins, cystatins, and proteolytically-derived peptides. The results indicate that acidic phosphoproteins as well as neutral and basic histatins from pure secretions selectively adsorb to hydroxyapatite, whereas in whole saliva some of these proteins are proteolytically degraded, dramatically changing its adsorption pattern.
The Fit of Gold-alloy Full-crown Castings Made with Ceramic Casting Ring Liners
Authors: Earnshaw R. , Morey E.F. 
Published: November 2010

Measurements were made of the fit of gold-alloy full-crown castings produced with dry ceramic ring liners. When used with vacuum investing, these liners absorb relatively large amounts of water from the investment mix (thereby reducing its original W/P ratio) and then function as wet liners, thus increasing the investment's potential expansion and giving castings which are consistently larger than when air investing is used. With four of the five liners tested, investing in air produced many castings which were unacceptably undersized (inaccuracy worse than -0.2%). The fifth liner, an industrial material 2 mm thick, gave only one casting out of 12 which was outside this limit, although all castings were undersized to a lesser extent. Vacuum investing gave improved casting accuracy; with four of the five liners, the improvement was highly significant (p < 0.001), and with the fifth, probably significant (p < 0.05). Even with vacuum investing, however, with only two of the liners did all castings show inaccuracies within ± 0.2%. With the other three liners, some castings (ranging from 2/10 to 7/9) had inaccuracies worse than -0.2%. With both air and vacuum investing, changing from one liner to another caused changes in relative casting accuracy which were often significant (p < 0.01) or highly significant (p < 0.001). In casting techniques where a ceramic ring liner is used, the choice of specific lining material and the choice between investing in air or under vacuum are important factors which can have a major effect on the fit of castings.
Distribution and Isolation Frequency of Eight Streptococcal Species in Saliva from Predentate and Dentate Children and Adults
Authors: Tappuni A.R. , Challacombe S.J. 
Published: November 2010

The isolation frequency and distribution of eight recently defined streptococcal species have been investigated in the saliva of adults and that of both predentate and dentate children. The effects of frequency of sugar intake and tooth presence on the distribution of streptococcal species were also analyzed. Saliva samples were collected from 121 subjects divided into three study groups: (a) 56 predentate children (predentate group), (b) 37 dentate children (dentate group), and (c) 28 adults (adult group). Up to 17 biochemical and enzymatic tests were used to categorize streptococcal isolates into S. mitis, S. oralis, S. salivarius, S. anginosus, S. sanguis, S. vestibularis, S. mutans, and S. gordonii. The mean total and streptococcal salivary colony-forming units (CFU) were lowest in the predentate group and highest in the adult group. Streptococci were found in all the study subjects, and there was no obvious relationship between the total or streptococcal CFU and the number of teeth or the frequency of sugar intake. There was a wide variation in the isolation frequency of streptococcal species in the three study groups. S. mitis, S. oralis, and S. salivarius were the most frequent species isolated, and together they comprised 83% of the total streptococcal isolates. In contrast to studies using older classifications, S. sanguis was a minor species in the saliva though found more often in adults than in children (p < 0.04). S. anginosus was a minor species found in about 10% of adults and children. S. gordonii was detected rarely and only in dentate subjects. S. mutans was detected only in dentate subjects, significantly greater in adults (57.1%) than in children (5.4%, p < 0.001). In contrast, S. vestibularis was found in both dentate and predentate children but not in adults. No relationship between the isolation frequency of any of the species and sugar intake in children was demonstrated. The new classification of streptococci has revealed major differences in isolation frequency and distribution of the individual species and should prove useful in future studies of ecological factors affecting oral flora.
Distribution of Substance P and Calcitonin Gene-related Peptide-like lmmunoreactive Nerve Fibers in the Rat Temporomandibular Joint
Authors: Kido M.A. , Kiyoshima T. , Kondo T. , Ayasaka N. , Moroi R. , Terada Y. , Tanaka T. 
Published: November 2010

The density and distribution of substance P-like immunoreactive (SP-LI) and calcitonin gene-related peptide-like immunoreactive (CGRP-LI) nerve fibers in rat temperomandibular joint (TMJ) were investigated in whole-mount preparations and frozen sections by immunohistochemistry with the avidin-biotin-peroxidase complex method. Both types of immunoreactive nerves were observed primarily in the joint capsule, the peripheral articular disc, the synovial membrane, and the periosteum. The distribution of CGRP-LI nerves was similar to that of SP-LI nerves. The anterior portion of the joint capsule and disc was most densely innervated, followed by the posterior, lateral, and medial portions. In addition, CGRP-LI nerves were more numerous and more dense in immunointensity than SP-LI nerves. In the synovial membrane, many SP- and CGRP-LI nerves terminated in the subsynovial layer, but some branches extended into the superficial synovial lining layer close to the joint cavity. Immunolabeled nerves were prominently located in the disc attachment and peripheral portion of the disc, and occasional nerves were located in the dense collagenous disc band as an actual disc. However, no fibers were detected in the central disc band. Thus, most of the disc was not innervated by any nerves. The present study provides a morphological basis for the possible roles of neuropeptides in endocytosis by synoviocytes, regulation of blood flow in the synovial membrane, nociception mechanisms of the TMJ, and modulation of the inflammatory response in the TMJ.
Fracture Toughness of Dentin/Resin-composite Adhesive Interfaces
Authors: Tam L.E. , Pilliar R.M. 
Published: November 2010

The reliability and validity of tensile and shear bond strength determinations of dentin-bonded interfaces have been questioned. The fracture toughness value (KIC) reflects the ability of a material to resist crack initiation and unstable propagation. When applied to an adhesive interface, it should account for both interfacial bond strength and inherent defects at or near the interface, and should therefore be more appropriate for characterization of interface fracture resistance. This study introduced a fracture toughness test for the assessment of dentin/ resin-composite bonded interfaces. The miniature short-rod specimen geometry was used for fracture toughness testing. Each specimen contained a tooth slice, sectioned from a bovine incisor, to form the bonded interface. The fracture toughness of an enamel-bonded interface was assessed in addition to the dentin-bonded interfaces. Tensile bond strength specimens were also prepared from the dentin surfaces of the cut bovine incisors. A minimum of ten specimens was fabricated for each group of materials tested. After the specimens were aged for 24 h in distilled water at 37°C, the specimens were loaded to failure in an Instron universal testing machine. There were significant differences (p < 0.05) between the dental adhesives tested. Generally, both the fracture toughness and tensile bond strength measurements were highest for AllBond 2, intermediate for 3M MultiPurpose, and lowest for Scotchbond 2. Scanning electron microscopy of the fractured specimen halves confirmed that crack propagation occurred along the bond interface during the fracture toughness test. It was therefore concluded that the mini-short-rod fracture toughness test provided a valid method for characterization of the fracture resistance of the dentin-resin composite interface.
Salivary Yeasts, Saliva, and Oral Mucosa in the Elderly
Authors: Narhi T.O. , Ainamo A. , Meurman J.H. 
Published: November 2010

Yeasts are commensals in the oral cavity and may not cause disease unless there are predisposing host factors, such as other disease, or when medication is being taken. The elderly are at increased risk of yeast infection. In this paper, prevalence of salivary yeasts in a group of 368 inhabitants of Helsinki aged 76, 81, and 86 years is reported. Salivary yeasts were counted by the Oricult-N® dip-slide method, salivary secretion rate and buffering capacity were measured, type of dentition was noted, and signs of yeast infection and the occurrence of subjective symptoms were determined. There was no growth of yeasts in 25% of the subjects. From one to 20 colonies/slide were observed in 21%, 21-50 colonies in 21%, and over 50 colonies (a high count) in 33%. Subjects with low salivary flow rates and low buffering capacities had significantly higher yeast counts than did subjects with normal salivary flow rates and buffering capacities. High yeast counts were found in 19% of subjects with natural teeth. The corresponding percentages in those wearing partial or complete dentures were 32 and 41, respectively. High salivary yeast counts were associated with oral mucosal lesions but not with subjective complaints of oral symptoms.
Diagnostic Value of Orthopedic Tests in Patients with Temporomandibular Disorders
Authors: Lobbezoo-Scholte A.M. , Steenks M.H. , Faber J.A.J. , Bosman F. 
Published: November 2010

For a better definition of diagnostic subgroups of patients with temporomandibular disorders (TMD), clinical orthopedic tests have been developed for the masticatory system, for use together with the commonly used active movement tests and palpation. In the present study, the characteristics and additional diagnostic value of four orthopedic tests-namely, passive opening, the joint play test, compression, and the static pain test-were determined for a patient group, diagnostic subgroups, and a control group. Significant differences among the scores of the tests in the different groups indicated that all six orthopedic tests contributed to the diagnostic process. Because of the close functional relationship of the masticatory system, most information was obtained when patients indicated where pain occurred during the different tests. Logistic regression techniques were used for determination of the relative diagnostic value of each orthopedic test in the diagnostic process. Active movement was the most powerful test for distinguishing the different subgroups. Palpation and passive opening were additionally useful for distinguishing between patients and control subjects and between the subgroups of arthrogenous and myogenous patients. Besides active movement, both compression and the joint play test played a minor role in the distinction of subgroups of arthrogenous patients. It may be concluded that in routine clinical practice, besides history taking and conventional radiography, a functional examination consisting of active movements, passive opening, and palpation provides valuable diagnostic information. In patients with a specific diagnostic problem, one of the other additional tests might be indicated.
Theoretical Study on the Electronic Configurations and Nature of Chemical Bonds of Dirhodium Tetraacetato Complexes [Rh2(CH3COO)4(L)2] (L = H2O, Free): Broken Symmetry Approach
Authors: Kataoka Yusuke , Kitagawa Yasutaka , Saito Toru , Nakanishi Yasuyuki , Matsui Toru , Sato Konomi , Miyazaki Yuhei , Kawakami Takashi , Okumura Mitsutaka , Mori Wasuke , Yamaguchi Kizashi 
Published: November 2010

Abstract
The electronic configurations and the nature of chemical bonds of the classical lantern-type dinuclear rhodium(II) tetraacetato complexes [Rh2(CH3COO)4(L)2] (L = H2O, free) have been carefully investigated with broken symmetry (BS) Hartree–Fock (HF), BS density functional theory (DFT), and BS hybrid DFT (HDFT) methods. Several electronic configurations have been proposed for the ground states of the [Rh2(RCOO)4(H2O)2] complexes. In this study, we concluded that those different electronic configurations originate from the position of the axial H2Os, and not along the Rh–Rh length. The BS(U)B3LYP calculation indicates that the stability of the σ and δ orbitals changed when the Rh–OH2 length was 2.35 Å. The natural orbital (NO) analyses and chemical indices clearly indicate that there is a σ-type single bond between the Rh ions, and that the axial H2Os does not affect the overlap.
Facile One-Step Synthesis of Double-Shelled CeO2 Hollow Spheres and Their Optical and Catalytic Properties
Authors: Ma Jingjing , Qian Kun , Huang Weixing , Zhu Yanhua , Yang Qing 
Published: November 2010

Abstract
Double-shelled CeO2 hollow microspheres (4–5 µm) were synthesized through a facile one-step hydrothermal treatment of Ce(NO3)3·6H2O in the presence of citric acid and hexamethylenetetramine (HMTA), and scanning and transmission electron microscopies demonstrated the samples are hollow spheres with litchi-like surfaces. The assembly of the hollow spheres was contributed to coordination effect of additives employed in the reaction system and the ripening growth in the process. Meanwhile, two other spherical structures including polyhedron-constituted and porous microspheres assembled with nanocrystals were also synthesized by varying the experimental parameters in the synthetic route. The UV–vis spectroscopic investigation demonstrated that the absorption edge of the three samples was blue shifted accordingly with their constituted primary crystallite sizes. In addition, investigation showed that the catalytic activities for CO oxidation of the three spheres types were considerably higher than those of commercial CeO2 powders, and their activities were in the order of porous &gt; litchi-like double-shelled hollow &gt; polyhedron-constituted, consistent with their BET surface area of 33, 22, and 10 m2 g−1. Specially, the litchi-like double-shelled hollow spheres showed much better catalytic properties per unit weight catalyst.
Enhancement in Cracking Activity of USY Zeolites Treated with Ammonium Nitrate Solution
Authors: Tomiyama Takuya , Okumura Kazu , Niwa Miki 
Published: November 2010

Abstract
USY zeolites prepared by steam treatment of NH4-Y zeolites were treated with ammonium nitrate solutions. Treatment with ammonium nitrate solutions resulted in a remarkable enhancement in the octane-cracking activity of the USY zeolites. This enhancement in the octane-cracking activity was attributed to the increase in the amount of acid sites and the enhancement of the acid strength, as observed in the ammonia IRMS–TPD method.