bluuebunny/crossref_metadata_2025 huggingface dataset:
An Empirical Test of the Validity of the Oral Health Status Index (OHSI) on a Minority Population
Authors: Spolsky V.W. , Marcus M. , Coulter I.D. , Der-Martirosian C. , Atchison K.A.
Published: January 2009

Disease varies in different populations based on sociodemographic variables, and there is limited understanding of this interaction. The purpose of this methodological study was to determine the validity of the Oral Health Status Index, a disease-based index, on a Hispanic population by comparing it with the NIDCR epidemiological measures of disease, with the addition of demographic and behavioral variables. The epidemiologic data were collected according to the criteria defined by the NIDCR, including: a modified Decayed Missing Filled Surfaces Index, gingival inflammation, calculus, and destructive periodontal disease measures. The demographic and behavioral variables were gathered from 240 interviews with Hispanic adults in two community clinics. Bivariate analysis was used to determine relationships between the descriptive epidemiologic, demographic, and behavioral variables and the Oral Health Status Index (OHSI). There were statistically significant differences (p < 0.05) in mean OHSI scores among the demographic variables age, education, income, and place of birth; and the behavioral variables alcohol consumption, flossing, and acculturation. Multiple regression analysis with the OHSI as the dependent variable showed that the statistically significant (p < 0.001) epidemiologic predictors were: percentage of Decayed Teeth/Decayed, Filled Teeth; Number of Replaced Teeth/Missing Teeth; and millimeters of mesial attachment loss. These collectively explained 47.49% of the variance in the regression. The addition of demographic variables to the epidemiologic regression identified age (p < 0.05), gender (p < 0.01), and place of birth (p < 0.01) as significant predictors that explained an additional 4.12% of the variance, collectively bringing the total explained variance to 51.61%. The behavioral variables did not contribute significantly to predicting the OHSI regression score. The Oral Health Status Index in this study is validated by its correlation with both the epidemiologic measures and the demographic variables. This combination of variables separated the Hispanics into Mexicans and Central/South Americans.
Incipient Analysis of Mesenchymal Stem-cell-derived Osteogenesis
Authors: Cooper L.F. , Harris C.T. , Bruder S.P. , Kowalski R. , Kadiyala S.
Published: January 2009

Tissue regeneration strategies invoke cell-based therapies for effective tissue formation. Current assessment of mesenchymal stem cell (MSC) directed bone regeneration during in vivo assays is dependent on histologic determination of bone formation. It was the aim of this study to determine the relationship between bone sialoprotein (BSP) expression and osteocalcin expression with subsequent osteogenesis occurring in MSC-based implants. RT-PCR assessment of human actin, collagen type I, BSP, and osteocalcin indicated that undifferentiated cells did not express BSP or osteocalcin. Three weeks following implantation, human BSP could be identified in RNAs isolated from the retrieved implants. For every implant from which human BSP cDNA was amplified, parallel implants harvested at 6 weeks demonstrated bone formation at the histologic level. This study confirms that, in the context of the severe combined immunodeficiency disease (SCID) mouse model, culture-expanded, cryopreserved human MSCs have osteogenic potential and demonstrates that implanted cell gene expression can reveal the early onset of bone formation.
Immunodominant Region of Actinobacillus actinomycetemcomitans 40-kilodalton Heat Shock Protein in Patients with Rheumatoid Arthritis
Authors: Yoshida A. , Nakano Y. , Yamashita Y. , Oho T. , Ito H. , Kondo M. , Ohishi M. , Koga T.
Published: January 2009

Bacterial heat shock proteins have been implicated in the pathogenesis of several diseases, and the immunological relationship between rheumatoid arthritis (RA) and Escherichia coli DnaJ has been reported. Since there are similarities in the tissue destruction process of RA and periodontitis, we examined the reactivities of antibodies in sera from RA patients to the DnaJ protein from Actinobacillus actinomycetemcomitans. An enzyme-linked immunosorbent assay showed that IgG titers to the N-terminal conservative region of the DnaJ are significantly higher in RA patients compared with the healthy controls (p < 0.05). Furthermore, we examined IgG titers of disease controls to determine the specificity of the immune responses to this region in RA patients. The difference between RA and infectious disease patients was also significant (p < 0.05). These results suggest that the N-terminal region of DnaJ from A. actinomycetemcomitans may contribute to the etiologic analysis of RA.
Validation of an in vitro Biofilm Model of Supragingival Plaque
Authors: Guggenheim B. , Giertsen E. , Schüpbach P. , Shapiro S.
Published: January 2009

The study of biofilm structure and function mandates the use of model systems for which a host of environmental variables can be rigorously controlled. We describe a model of supragingival plaque containing Actinomyces naeslundii, Veillonella dispar, Fusobacterium nucleatum, Streptococcus sobrinus, and Streptococcus oralis wherein cells are cultivated anaerobically in a saliva-based medium on hydroxyapatite discs coated with a salivary pellicle, with material and pieces of apparatus common to all microbiology laboratories. After 0.5 hr, 16.5 hrs, 40.5 hrs, and 64.5 hrs, the composition of adherent biofilms was analyzed by culture techniques, live/dead fluorescence staining, and confocal laser scanning microscopy. Repeated independent trials demonstrated the repeatability of biofilm formation after 40.5 hrs and 64.5 hrs. Brief exposures of biofilms to chlorhexidine or Triclosan produced losses in viability similar to those observed in vivo. This biofilm model should prove very useful for pre-clinical testing of prospective anti-plaque agents at clinically relevant concentrations.
pH-regulated Secretion of a Glyceraldehyde-3-Phosphate Dehydrogenase from Streptococcus gordonii FSS2: Purification, Characterization, and Cloning of the Gene Encoding this Enzyme
Authors: Nelson D. , Goldstein J.M. , Boatright K. , Harty D.W.S. , Cook S.L. , Hickman P.J. , Potempa J. , Travis J. , Mayo J.A.
Published: January 2009

Streptococcus gordonii and other viridans streptococci (VS) are primary etiologic agents of infective endocarditis, despite being part of the normal oral microflora. Recently, a surface-bound glyceraldehyde-3 -phosphate dehydrogenase (GAPDH) has been found on the cells of all tested streptococcal species, where it has been implicated as a virulence factor. In contrast, we observed that a soluble extracellular GAPDH was the major secreted protein from S. gordonii FSS2, an endocarditis strain. The biochemical properties and gene sequence of S. gordonii GAPDH are almost identical to those of other streptococcal GAPDHs. Growth at defined pHs showed that secretion of GAPDH is regulated by environmental pH. GAPDH was primarily surface-associated at growth pH 6.5 and shifted to > 90% secreted at growth pH 7.5. Others have identified S. gordonii promoters that are up-regulated by a pH shift similar to that experienced by organisms entering the blood stream (neutral) from the oral cavity (slightly acid). Analysis of our results suggests that secretion of GAPDH may be a similar adaptation by S. gordonii.
Move of Adults with Mental Retardation from Institutions to Community-based Living: Changes in the Oral Microbiological Flora
Authors: Gabre P. , Wikström M. , Martinsson T. , Gahnberg L.
Published: January 2009

In the Western world, the policy of de-institutionalization and integration of individuals with mental retardation is generally accepted. We tested the hypothesis that de-institutionalization may lead to changes of habits with a potential to influence oral health. When 57 adults with mental retardation moved from an institution to community-based living, their oral hygiene habits, gingival bleeding, and a three-day food record were registered one month before and 9 and 21 months after the move. Mutans streptococci and lactobacilli in saliva, P. intermedia/P. nigrescens, P. gingivalis, and A. actinomycetemcomitans in supragingival plaque, and C. albicans on mucous membranes were analyzed. After 21 months of community-based living, fewer persons showed high classes of mutans streptococci, growth of P. intermedia/P. nigrescens, and high frequency of sucrose intake, and more subjects showed growth of C. albicans. In a short perspective, the indicators of oral diseases suggest an unchanged or lower risk of oral diseases after the de-institutionalization of individuals with moderate or severe mental retardation.
Occlusal Stability in Shortened Dental Arches
Authors: Witter D.J. , Creugers N.H.J. , Kreulen C.M. , de Haan A.F.J.
Published: January 2009

Shortened dental arches consisting of anterior and premolar teeth have been shown to meet oral functional demands. However, the occlusal stability may be at risk as a result of tooth migration. The aim of this nine-year study was to investigate occlusal stability in shortened dental arches as a function over time. Occlusal stability indicators were: 'interdental spacing', 'occlusal contacts of anterior teeth in Intercuspal Position', 'overbite', 'occlusal tooth wear', and 'alveolar bone support'. Subjects with shortened dental arches (n = 74) were compared with subjects with complete dental arches (controls, n = 72). Repeated-measurement regression analyses were applied to assess age-dependent variables in the controls and to relate the occlusal changes to the period of time since the treatment that led to the shortened dental arches. Compared with complete dental arches, shortened dental arches had similar overbite and occlusal tooth wear. They showed more interdental spacing in the premolar regions, more anterior teeth in occlusal contact, and lower alveolar bone scores. Since the differences remained constant over time, we conclude that shortened dental arches can provide long-term occlusal stability. Occlusal changes were self-limiting, indicating a new occlusal equilibrium.
Motion of the Human Mandibular Condyle during Mastication
Authors: Miyawaki S. , Tanimoto Y. , Kawakami T. , Sugimura M. , Takano-Yamamoto T.
Published: January 2009

It has been reported that loading to the mandible during closing movement makes the condylar path move more in the superior direction than that during the free closing movement. In this study, the hypothesis was tested that the displacement of the condyle on the chewing side is greater in the direction of the mandibular fossa than that on the non-chewing side. Using a six-degrees-of-freedom jaw movement recording system, we recorded condylar motion in 12 healthy adults without TMD, during the chewing of a large hard gummy jelly. The maximum displacements at the condyle on the chewing side from the maximum intercuspation (CO) position were significantly larger in the superior and medial directions at the initial stage and in the posterior direction at all stages (0.5 mm, 0.5 mm, and 0.6 mm, respectively) than those on the non-chewing side (0.0 mm, 0.1 mm, and 0.1 mm, respectively). This suggests that, in healthy adults, the condyles at CO are located in a position such that excessive load is not applied to the temporomandibular joint when there are the aforementioned displacements.
Rhythmic Masticatory Muscle Activity during Sleep in Humans
Authors: Lavigne G.J. , Rompré P.H. , Poirier G. , Huard H. , Kato T. , Montplaisir J.Y.
Published: January 2009

Rhythmic Masticatory Muscle Activity (RMMA) is frequently observed during sleep in normal subjects and sleep bruxers. We hypothesized that some normal subjects exhibit RMMA at a lower frequency than sleep bruxers. Polysomnographic data from 82 normal subjects were compared with data from 33 sleep bruxers. RMMA episodes were defined as three or more consecutive bursts of masseter EMG activity, with or without tooth-grinding. Such episodes were observed in nearly 60% of normal subjects. A lower frequency of episodes was noted in normal subjects than in bruxers. Sleep organization was similar between groups. Bruxers had twice as many masseter muscle bursts per episode and episodes of higher amplitude compared with controls with RMMA. The high prevalence of RMMA observed in normal subjects suggests that this activity is related to certain sleep-related physiological functions, including autonomic activation.
Accuracy of Kubelka-Munk Reflectance Theory Applied to Human Dentin and Enamel
Authors: Ragain J.C. , Johnston W.M.
Published: January 2009

The Kubelka-Munk (K-M) theory provides a reflectance model for translucent materials placed on backings of different colors. We hypothesize that Kubelka-Munk (K-M) theoretical diffuse reflectance spectra of dentin and enamel are in good agreement with observed diffuse reflectance. The aim of this study was to measure the reflectance of enamel and dentin specimens and to compare the measured values of reflectance with K-M theoretical values. Disc-shaped specimens of enamel, dentin, and enamel/dentin were prepared from extracted teeth. Diffuse reflectance spectra were measured on three backings by means of a reflectance spectrophotometer over every wavelength (λ) from 400 to 700 nm at three thicknesses. The measured reflectance values were fit by non-linear regression to corrected K-M theory. The low value of the reported errors associated with the application of K-M theory illustrated that the theoretical diffuse reflectance spectra of dentin and enamel are in good agreement with the observed diffuse reflectance.
Mechanical Stimulation Induces CTGF Expression in Rat Osteocytes
Authors: Yamashiro T. , Fukunaga T. , Kobashi N. , Kamioka H. , Nakanishi T. , Takigawa M. , Takano-Yamamoto T.
Published: January 2009

Connective tissue growth factor (CTGF), which is encoded by an immediate early gene and a member of the CCN family, has been shown to be expressed in osteoblasts, fibroblasts, and chondrocytes. Although CTGF is expressed in bone and cartilage tissues, we tested the hypothesis that CTGF is regulated in mechanotransduction. In the alveolar bone during experimental tooth movement, CTGF mRNA was expressed in osteoblasts and in osteocytes localized around the periodontal ligament under control conditions. Interestingly, 12 hrs after the start of experimental tooth movement, the expression of CTGF mRNA in osteocytes and osteoblasts became more intense around the periodontal ligament, and the intense expression of CTGF extended to osteocytes situated deep in alveolar bone matrix apart from periodontal ligament in both tension and compression sides. Our present findings indicate that CTGF could play a role in regulation of osteocyte function during the mechanical stimulation of bone.
Glucosyltransferase Inactivation Reduces Dental Caries
Authors: Devulapalle K.S. , Mooser G.
Published: January 2009

Dental caries has been an intractable disease in spite of intense dental research. The metabolic acids produced by mutans streptococci demineralize the tooth surface and lead to dental caries. The enzyme glucosyltransferase (GTF) produced by mutans streptococci is the key factor in this process. Oral bacterial GTFs use sucrose as a substrate in synthesis of either water-soluble or insoluble glucans. In this investigation, kinetic studies with divalent metal ions revealed their strong binding affinity to GTF. The metal ions also proved to be strong inhibitors of the enzyme. Here we describe a simple method of inactivating the enzyme that actively participates in dental caries by taking advantage of a Fenton reaction which requires metal ions such as iron or copper and peroxide. The hydroxyl radical ions produced via the Fenton reaction inactivate GTF, a factor in the production of dental caries.
Differences in Parasympathetic Vasodilator and Salivary Responses in the Cat Submandibular Gland between Lingual and Chorda-lingual Nerve Stimulation
Authors: Sato A. , Izumi H. , Nakamura I. , Karita K.
Published: January 2009

Experimental activation of parasympathetic vasodilatation and salivation in the submandibular gland by a "pseudoreflex" method has definite advantages over other commonly used methods. However, it is unclear which stimulation sites allow for avoidance of direct activation of the parasympathetic efferents to this gland. We examined this question in heavily anesthetized (a-chloralose and urethane), artificially ventilated, cervically vagosympathectomized cats, using the intersection of the chorda-lingual nerve and the submandibular gland duct ("the intersection") as our reference point. Both vasodilatation and salivation evoked by electrical stimulation of the lingual nerve were abolished by section of the chorda-lingual nerve (10 mm proximal to the intersection), provided the stimulation site was distal to the intersection by 4 mm or more. This salivation was abolished by the muscarinic receptor antagonist, scopolamine. Thus, by careful choice of stimulation site, submandibular gland responses mediated solely by reflex parasympathetic mechanisms can be evoked by lingual nerve stimulation in this preparation.
Adhesion of N-Methacryloyl-ω-Amino Acid Primers to Collagen Analyzed by 13C NMR
Authors: Nishiyama N. , Suzuki K. , Asakura T. , Komatsu K. , Nemoto K.
Published: January 2009

Previously, we reported that the strength of the interaction between N-methacryloyl-w-amino acid (NMωA) primers and dentinal collagen exhibited a strong correlation with the bond strength of the resin to etched dentin. To determine the pertinent functional groups of the amino acid residues in the dentinal collagen, to which the amide and/or the carboxylic acid groups of the NMwAs are adsorbed, we used 13C NMR techniques-primarily through the observation of spin-lattice relaxation times, Ti—to investigate the adsorption characteristics resulting from the interaction of NMwAs with a model oligopeptide for collagen, (PPG)5. The addition of NMωAs to a collagenous solution resulted in a decrease in the T1 values of the carbonyl carbons attributed to the carboxylic acid of the C-terminal Gly and to the third amide of the N-terminal Pro residues in the (PPG)5 molecule, thus reflecting the formation of hydrogen-bonded interactions.
Dynamic Properties of the Human Temporomandibular Joint Disc
Authors: Beek M. , Aarnts M.P. , Koolstra J.H. , Feilzer A.J. , Van Eijden T.M.G.J.
Published: January 2009

The cartilaginous intra-articular disc of the human temporomandibular joint shows clear anteroposterior variations in its morphology. However, anteroposterior variations in its tissue behavior have not been investigated thoroughly. To test the hypothesis that the mechanical properties of fresh human temporomandibular joint discs vary in anteroposterior direction, we performed dynamic indentation tests at three anteroposteriorly different locations. The disc showed strong viscoelastic behavior dependent on the amplitude and frequency of the indentation, the location, and time. The resistance against deformations and the shock absorbing capabilities were larger in the intermediate zone than in regions located more anteriorly and posteriorly. Because several studies have predicted that the intermediate zone is the predominantly loaded region of the disc, it can be concluded that the topological variations in its tissue behavior enable the disc to combine the functions of load distribution and shock absorption effectively.
Antifungal Resistance of Candidal Biofilms Formed on Denture Acrylic in vitro
Authors: Chandra J. , Mukherjee P.K. , Leidich S.D. , Faddoul F.F. , Hoyer L.L. , Douglas L.J. , Ghannoum M.A.
Published: January 2009

Denture biofilms represent a protective reservoir for oral microbes. The study of the biology of Candida in these biofilms requires a reliable model. A reproducible model of C. albicans denture biofilm was developed and used to determine the susceptibility of two clinically relevant C. albicans isolates against 4 antifungals. C. albicans, growing as a biofilm, exhibited resistance to amphotericin B, nystatin, chlorhexidine, and fluconazole, with 50% reduction in metabolic activity (50% RMA) at concentrations of 8, 16, 128, and > 64 μg/mL, respectively. In contrast, planktonically cultured C. albicans were susceptible (50% RMA for the same antifungals was obtained at 0.25, 1.0, 4.0, and 0.5 μg/mL, respectively). In conclusion, results obtained by means of our biofilm model show that biofilm-associated C. albicans cells, compared with cells grown in planktonic form, are resistant to antifungals used to treat denture stomatitis.
Chewing Stimulates Secretion of Human Salivary Secretory Immunoglobulin A
Authors: Proctor G.B. , Carpenter G.H.
Published: January 2009

Immunoglobulin A (IgA) is the most abundant immunoglobulin in saliva and other mucosal secretions and plays an important role in mucosal immunity. The present study examined whether secretion of IgA, like other salivary proteins, is increased by reflex stimulation. Parotid saliva was collected from subjects into separate vials under resting conditions and during chewing-stimulated secretion over 45 min. Enzyme-linked immunosorbent assay (ELISA) indicated that chewing increased IgA secretion. The extent and pattern of the increase were similar to those of total protein and acinar cell amylase. SDS gel electrophoresis and Western blotting showed that high-molecular-weight forms of IgA-containing secretory component predominated in all saliva samples. Secretory component, the cleaved epithelial receptor for polymeric IgA, was secreted in a pattern very similar to that of IgA. It is concluded that chewing stimulates epithelial cell transcytosis of IgA and increases secretion of secretory IgA into saliva.
Increased Frequency of FcγRIIIb-NA1 Allele in Periodontitis-resistant Subjects in an Elderly Japanese Population
Authors: Sugita N. , Kobayashi T. , Ando Y. , Yoshihara A. , Yamamoto K. , Van de Winked J.G.J. , Miyazaki H. , Yoshie H.
Published: January 2009

Many elderly people show minimum periodontal tissue destruction, which might be partly due to genetic advantages in host immune response against periodontopathic bacteria. The human IgG Fc receptor IIIb on neutrophils bears a NA1-NA2 polymorphism. The FcγRIIIb-NA1 displays a more efficient interaction with IgGl- and IgG3-opsonized bacteria, compared with the FcγRIIIb-NA2. We investigated a 70-year-old Japanese population (n = 599) to determine whether the FcγRIIIb polymorphism was associated with resistance to periodontitis. Among subjects with≥ 20 teeth present, periodontitis-resistant (n = 46) and periodontitis-susceptible groups (n = 73) were selected based on the percentage of sites with ≥ 4 mm probing attachment loss in the entire dentition. The FcγRIIIb-NA1 allotype was overrepresented in the periodontitis-resistant group, compared with the periodontitis-susceptible group (χ2 = 4.89, p = 0.03, odds ratio = 1.87, 95% CI, 1.07 to 3.28). This suggests that FcγRIIIb-NA1 may be associated with resistance to periodontitis.
A Novel Mutation in the Keratin 13 Gene Causing Oral White Sponge Nevus
Authors: Terrinoni A. , Rugg E.L. , Lane E.B. , Melino G. , Felix D.H. , Munro C.S. , McLean W.H.I.
Published: January 2009

White sponge nevus (WSN) is an autosomaldominantly inherited form of mucosal leukokeratosis. Defects in keratins, proteins that form the stress-bearing cytoskeleton in epithelia, have been shown to cause several epithelial fragility disorders. Recently, mutations in the genes encoding mucosal-specific keratins K4 and K13 were shown to be the underlying cause of WSN. We have studied a large Scottish family with 19 persons affected by WSN in four generations. The K4 locus was excluded by genetic linkage analysis; however, genetic linkage consistent with a K13 defect was obtained. Subsequently, a heterozygous missense mutation 335A>G was detected in exon 1 of the KRT13 gene, predicting the amino acid change N112S in the 1A domain of the K13 polypeptide. The mutation was confirmed in affected family members and was excluded from 50 unaffected people by restriction enzyme analysis. These results confirm that mucosal keratin defects are the cause of WSN.
Randomized Controlled Evaluation of Non-surgical Treatments for Temporomandibular Joint Anterior Disk Displacement without Reduction
Authors: Minakuchi H. , Kuboki T. , Matsuka Y. , Maekawa K. , Yatani H. , Yamashita A.
Published: January 2009

The common methods for treating anterior disk displacement without reduction (ADDwor) are not based on randomized controlled clinical trials. Our study evaluated non-surgical treatments in 69 MRI-confirmed ADDwor subjects (m/f = 6/63). Subjects were randomly assigned to a control group and one of two treatment groups. Outcomes included maximum mouth opening, visual analogue scale of pain, and daily activity limitation. Calibrated examiners collected data at the initial interview and at 0, 2, 4, and 8 weeks of treatment. At the eight-week point, within-group improvements were present for all variables, for all groups. Between-group differences were not highly evident, with only mean daily activity limitation for the self-care/NSAID group being significantly lower than that of the occlusal appliance/jaw mobilization + self-care/NSAID group at the two- and four-week time-points. These results suggest that ADDwor subjects will improve with only minimal treatment intervention, and no significant difference was evident for the treatments tested and the control condition.
Remineralization of Caries Lesions Extending into Dentin
Authors: ten Cate J.M.
Published: January 2009

Remineralization is one aspect of the overall process of tooth decay. However, it is primarily studied in shallow lesions. The aim of this study was to explore whether caries lesions in enamel and extending into the dentin can be remineralized. A single-section model was developed for the longitudinal and non-destructive monitoring of changes in enamel and dentin. Lesions at least 200 μm into dentin were formed in undersaturated acetate buffers. Next, the lesions were divided into groups (three treatment and one control) and remineralized. The treatments were: weekly immersion in 1000 ppm fluoride, single treatment with methanehydroxybisphosphonate, and a constant level of 1 ppm fluoride. De- and remineralization was assessed by transverse microradiography. Remineralization was observed in enamel, but also in dentin, indicating that, deep into dentin, the pores become supersaturated to apatite formation. Treatments affected remineralization only in the outer part of enamel. Both findings are explained by a relatively fast diffusion of mineral ions, with precipitation being rate-limiting. The results suggest that dentin remineralization, underneath enamel, can be achieved and could possibly be used in clinical treatment strategies.
Distribution and Excretion of TEGDMA in Guinea Pigs and Mice
Authors: Reichl F.X. , Durner J. , Hickel R. , Kunzelmann K.H. , Jewett A. , Wang M.Y. , Spahl W. , Kreppel H. , Moes G.W. , Kehe K. , Walther U. , Forth W. , Hume W.R.
Published: January 2009

The monomer triethyleneglycoldimethacrylate (TEGDMA) is used as a diluent in many resin-based dental materials. It was previously shown in vitro that TEGDMA was released into the adjacent biophase from such materials during the first days after placement. In this study, the uptake, distribution, and excretion of 14C-TEGDMA applied via gastric, intradermal, and intravenous administration at dose levels well above those encountered in dental care were examined in vivo in guinea pigs and mice as a test of the hypothesis that TEGDMA reaches cytotoxic levels in mammalian tissues. 14C-TEGDMA was taken up rapidly from the stomach and small intestine after gastric administration in both species and was widely distributed in the body following administration by each route. Most 14C was excreted within one day as 14 CO2. The peak equivalent TEGDMA levels in all mouse and guinea pig tissues examined were at least 1000-fold less than known toxic levels. The study therefore did not support the hypothesis.
Impairment of Gingival Fibroblast Adherence by IL-6/sIL-6R
Authors: Naruishi K. , Takashiba S. , Nishimura F. , Chou H.-H. , Arai H. , Yamada H. , Murayama Y.
Published: January 2009

Interleukin-6 (IL-6) binds to human gingival fibroblasts (HGF) in the presence of a soluble form of IL-6 receptor (sIL-6R). We investigated the effects of IL-6 on the functions of HGF in the presence of sIL-6R. HGF changed their morphology from spindle-shaped to round, and detached from the culture dish by stimulation with IL-6/sIL-6R. In this condition, a signal transducer gpl30 and a transcription factor Stat3 were phosphorylated, resulting in activation of transcription factors Stat3 and C/EBPβ. Cytoskeletal β-actin and adhesion molecule integrin-a5, a subunit of α5β1 integrin (VLA-5), were found to possess potential binding domains for these transcription factors in their promoters. Accumulation of (3-actin and integrin-a5 mRNA decreased, contrary to the expectation of the induction of gene transcription. Furthermore, the decrease in their mRNAs was associated with reduced expression of both actin and VLA-5 proteins. These results suggest that the expression of VLA-5 and actin was down-regulated in HGF through an IL-6 signaling pathway, resulting in impairment of HGF adherence.
Preferential Utilization of Dipeptides by Porphyromonas gingivalis
Authors: Takahashi N. , Sato T.
Published: January 2009

Although Porphyromonas gingivalis is known to utilize peptides preferentially, instead of free amino acids, as the source of energy and cell material, there is only limited information on what sizes and kinds of peptide this bacterium preferentially utilizes. In this study, therefore, we tested aspartate or glutamate monopolymers consisting of from 2 to 100 amino acids as metabolic substrates for P. gingivalis. The washed cells of P. gingivalis consumed aspartylaspartate and glutamylglutamate, and produced large amounts of ammonia and organic acids such as propionate and butyrate, while the cells formed only small amounts of end-products from aspartate, glutamate, and other peptides longer than a dipeptide. P. gingivalis also metabolized valylvaline and leucylleucine and produced isobutyrate and isovalerate, respectively, only in the presence of aspartylaspartate or glutamylglutamate. This suggests a metabolic linkage between these dipeptides. These results clearly indicate that P. gingivalis utilizes dipeptides preferentially as its metabolic substrates.
Confocal Microscopy Study of Undisturbed and Chlorhexidine-treated Dental Biofilm
Authors: Zaura-Arite E. , van Marle J. , ten Cate J.M.
Published: January 2009

Culturing of dispersed plaque samples and vitality staining of plaque smears are the most commonly used methods for evaluating the effects of antimicrobials on dental plaque. The visualization of the antimicrobial action on oral biofilm present on the substrate surface ( in situ) would add valuable information to the existing knowledge about the treatment effects. This study aimed at combining the advantage of confocal laser scanning microscopy (CLSM) to visualize plaque non-destructively with a vitality staining technique to assess the immediate bactericidal effect of chlorhexidine (CHX) on biofilm. Three 200-μmwide grooves were cut into bovine dentin discs for plaque accumulation. The discs were worn by six subjects for 6, 24, and 48 hrs, then broken into halves, one of which received a one-minute extra-oral 0.2% CHX treatment, while the other served as control. Both halves were stained for vital fluorescence measurements and visualized by CLSM. Plaque vitality (in %) was quantified by image analysis in three plaque layers-outer, middle, and inner. The CHX effect was significant in six-hour samples (p < 0.001) and only in the outer layer of the 48-hour plaque (p < 0.001), demonstrating a resistant nature of dental biofilm to a single CHX treatment. With the present approach, we have shown that it is possible to visualize and quantitate the antimicrobial treatment effect on biofilm still present on the substrate on which it was grown.
Spontaneous Fluctuations in the Concentrations of Oral Sulfur-containing Gases
Authors: Springfield J. , Suarez F.L. , Majerus G.J. , Lenton P.A. , Furne J.K. , Levitt M.D.
Published: January 2009

Breath hydrogen sulfide (H 2S) and methylmercaptan (CH3SH) concentrations are used as quantitative indicators of halitosis. However, measurements of these gases in duplicate oral samplings often show poor reproducibility. To determine if this poor reproducibility is an artifact of the collection/analytical procedure or a true biological phenomenon, we used a standardized technique to collect from 20 to 30 oral gas samples at two-minute intervals from 11 healthy subjects. The samples were analyzed for sulfur gases and CO2. Sizable variations in H2S and CH3SH concentrations were not associated with alterations in CO2, indicating that the variations did not reflect variable contamination with atmospheric or pulmonary gas. In addition, fluctuations in H2S and CH3SH were not identical and often were not random. We conclude that minute-to-minute variability in oral sulfur gas concentrations is a true biological phenomenon. This fluctuation complicates experimental studies designed to show that interventions alter halitosis.
An Oral Health Survey in Southern China, 1997: Background and Methodology
Authors: Schwarz E. , Zhang H.G. , Wang Z.J. , Lin H.C. , Lo E.C.M. , Corbet E.F. , Wong M.C.M.
Published: January 2009

Relatively limited information is available about the oral health in the Guangdong Province of Southern China, the closest neighbor to Hong Kong. The study intended to explore the oral health status, knowledge, attitudes, and dental care utilization in the Guangdong population as a basis for formulating strategies for oral health prevention and treatment. Through multi-stage stratified and quota-sampling, individuals from urban as well as rural communities were selected (5- to 6-; 12-; 35- to 44-; and 65- to 74-year-olds; total N = 6251). Structured interviews and clinical examinations were performed. Inter-examiner reliability was high (K = 0.60-0.96). Samples of community water were taken for fluoride assessment. Overall, the sample surveyed was acceptably representative of the population, with some under-representation of rural residents and agricultural workers. Re-weighting was performed in appropriate analyses. The data analysis model used in the Second International Collaborative Study was used as a guide for the present data analysis. This approach has not previously been used on a Mainland Chinese population.
Oral Health Knowledge, Attitudes, and Practices of Chinese Adults
Authors: Lin H.C. , Wong M.C.M. , Wang Z.J. , Lo E.C.M.
Published: January 2009

Only recently have behavioral aspects been taken into consideration in oral health studies in China; thus, relevant information on perceptions in adult Chinese about oral health care is inadequate. In 1996-97, a large-scale oral epidemiological study was conducted in Southern China. Among its objectives were to describe the oral health knowledge, attitudes, and practices of the urban and rural adults living in Southern China and to analyze the influence of selected demographic and socio-economic factors. From 8 urban and 8 rural communities in Guangdong Province, 1573 35- to 44-year-olds and 1515 65- to 74-year-olds were sampled. Specially trained interviewers from the staff of local government or hospitals conducted face-to-face structured interviews. Almost all of the middle-aged and more than 90% of the dentate elderly surveyed claimed that they brushed their teeth every day and used toothpaste during toothbrushing, but awareness about fluoride content was lacking. The respondents had poor oral health knowledge but positive attitudes toward oral health, providing a basis for more community-based oral health education programs, especially targeting adults who are less-well-educated and have fewer socio-economic advantages.
Utilization of Dental Services in Southern China
Authors: Lo E.C.M. , Lin H.C. , Wang Z.J. , Wong M.C.M. , Schwarz E.
Published: January 2009

A population's utilization of dental services is an important parameter in oral health care planning, which has rarely been studied in China. The objectives of this report were to describe the dental service utilization pattern of middle-aged and elderly Chinese and to analyze the influence of selected variables on the use of dental services. A Guangdong Province population of 1573 35- to 44-year-olds and 1515 65- to 74-year-olds recruited from urban and rural communities was interviewed in their local dialect. It was found that 23% of the middle-aged and 24% of the elderly subjects had visited a dentist within the preceding year. The two most commonly cited reasons for not having seen a dentist for at least 3 years were: no perceived need, and no serious dental problems. Among subjects who had visited a dentist within 3 years, the 3 most commonly received treatments were: fillings, extractions, and dental prostheses. Furthermore, a logistic regression analysis showed that women, subjects who lived in urban areas, were better educated, were wealthier, and had better oral health knowledge were more likely to be a recent dental service user. In conclusion, dental service utilization among the adult Southern Chinese was found to be low, problem-driven, and influenced by some socio-economic factors.
Periodontal Conditions in Adult Southern Chinese
Authors: Corbet E.F. , Wong M.C.M. , Lin H.C.
Published: January 2009

Periodontal diseases remain a concern in adult populations, but there have been no systematic descriptions of periodontal conditions, which have included periodontal attachment loss, among Southern Chinese. The main aim of this report is to describe the periodontal conditions in adult Chinese and to investigate factors that may have influenced periodontal attachment loss. Subjects were recruited from urban and rural survey sites throughout Guangdong. In total, 1572 35- to 44-year-old subjects and 1286 65- to 74-year-old subjects completed a structured interview and underwent a periodontal examination, which included the Community Periodontal Index (CPI) and periodontal Attachment Loss (ALoss) recordings. Calculus was found as the highest CPI score in 61-68% of the 35- to 44-year-old subjects and in 54-57% of the 65- to 74-year-olds. Shallow pockets were found as the highest CPI score in about one-third of both the urban and the rural subjects in both age groups, and deep pockets in 3-7% of the subjects. ALoss was more prevalent than pockets in both age groups. On the basis of the ALoss recordings, about one-third of the subjects in both age groups were categorized as exhibiting considerable ALoss for their age. In both age groups, logistic regression analysis indicated that being male, wearing partial dentures, and reporting less frequent toothbrushing were found to be associated with considerable ALoss.
Tooth Loss, Occluding Pairs, and Prosthetic Status of Chinese Adults
Authors: Lin H.C. , Corbet E.F. , Lo E.C.M. , Zhang H.G.
Published: January 2009

The objectives of this analysis were to describe the numbers of teeth lost and those indicated for extraction, dental prosthetic status, and occluding tooth pairs among adults in Southern China and to investigate factors affecting tooth mortality. A sample consisting of 1573 35- to 44-year-old and 1515 65- to 74-year-old urban and rural Chinese was examined clinically by calibrated examiners. Teeth not present for any reason were defined as missing (MT). The sum of MT and teeth indicated for extraction (IMT) was defined as adjusted missing teeth (AMT). Only 4.4% of the urban and 3.4% of the rural 65- to 74-year-olds were edentulous. MT were not significantly different between urban and rural residents, but more IMT were found in rural residents. Women, those who had a lower education level, and those who were less wealthy had more AMT in both age groups. Smoking was found to be associated with AMT in the 35- to 44-year-olds. Eighteen percent of the urban and 27% of the rural elderly had no occluding tooth pairs after IMT were accounted for, and only 38% and 30%, respectively, had 10 or more occluding pairs. Fifty-one percent of the urban and 43% of the rural elderly were found to have some form of dental prostheses in either jaw. A partial denture was more common in urban residents in both age groups.
Tumor Necrosis Factor-a and its Receptors, p55 and p75, in Gingiva of Adult Periodontitis
Authors: Tervahartiala T. , Koski H. , Xu J.-W. , Häyrinen-Immonen R. , Hietanen J. , Sorsa T. , Konttinen Y.T.
Published: January 2009

Tumor necrosis factor-a. (TNF-a), a pro-inflammatory cytokine, can stimulate matrix metalloproteinase synthesis and osteoclastic bone resorption. We hypothesized that elevated expression of TNF-a and its p55 and p75 receptors (TNF-R) in gingival tissue might associate with periodontitis. Immunohistochemistry was used for the study of the localization of TNF-a and its p55 and p75 TNF-R in adult periodontitis (AP) gingival tissue, in comparison with that in healthy control specimens. TNF-a and p55 TNF-R were detected in sulcular epithelial basal cells and in monocyte/macrophages, fibroblasts, and endothelial cells in the AP gingival tissue specimens, but mainly in fibroblasts and endothelial cells in control specimens. P75 TNF-R was occasionally found in monocyte/macrophage-like cells in gingival tissue specimens. The percentage of TNF-a-containing cells was not increased in AP compared with controls (13.2% ± 6.1% vs. 12.8% ± 7.6%), but, due to the increased cellularity of AP samples, the number of TNF-a positive cells/mm2 was clearly increased (1621 ± 663 vs. 664 ±191, p > 0.001). Thus, AP gingival tissue has an elevated expression of TNF-a and especially its p55 receptor, suggesting that TNF-a may contribute to tissue degradation in periodontitis.
Osteoblast Integrin Adhesion and Signaling Regulate Mineralization
Authors: Schneider G.B. , Zaharias R. , Stanford C.
Published: January 2009

Integrin adhesion and signaling events may contribute to the progressive differentiation of the osteoblast and to the initiation of a mineralized matrix. The purpose of our study was to begin to analyze the role of integrin receptors, in particular α2β1, α5β1, and αVβ3, regarding mediation of the initiation of a mineralized matrix. Integrin-perturbation assays were conducted in microdot cultures of UMR-106-01 Bone Sialoprotein (BSP) osteoblast cells. For phenotypic analysis, we performed bright-field microscopy and Aliziran Red S staining to analyze effects on mineralization initiation. Mineralization was reduced significantly (P < 0.001) following the addition of a5- or β1-integrin subunit antibody by approximately 20% and 45%, respectively—αVβ3 integrin by nearly 65%, and α2β1 integrin by nearly 95%. This effect was reversible following the removal of the anti-integrin antibody. These results suggest that integrin adhesion and signaling events may contribute to the ability of this cell line to mediate the initiation of the mineralization phenotype biologically.
Salivary Non-immunoglobulin Agglutinin Inhibits Human Leukocyte Elastase Digestion of Acidic Proline-rich Salivary Proteins
Authors: Boackle R.J. , Dutton S.L. , Fei H. , Vesely J. , Malamud D. , Furness A.R.
Published: January 2009

Saliva contains acidic proline-rich salivary proteins that are involved in the formation of the salivary pellicle coating supragingival tooth surfaces. However, human leukocyte elastase, arriving in gingival exudates from inflamed periodontal tissues, degrades the acidic proline-rich salivary proteins, preventing binding to hydroxylapatite surfaces. Here it is reported that high-molecular-weight non-immunoglobulin salivary agglutinin inhibited the proteolytic action of human leukocyte elastase on purified acidic proline-rich salivary proteins. Inhibition was eliminated with monoclonal antibody to a protein determinant on the salivary agglutinin. The addition of antibody against salivary agglutinin blocked the inhibitory effect of parotid saliva on exogenously applied human leukocyte elastase, allowing for the elastase-mediated digestion of the salivary acidic proline-rich salivary proteins. Salivary agglutinin, therefore, is a physiologically important inhibitor of human leukocyte elastase and is able to inhibit elastase-mediated digestion of salivary acidic proline-rich proteins.
Intrafibrillar Mineral May be Absent in Dentinogenesis Imperfecta Type II (DI-II)
Authors: Kinney J.H. , Pople J.A. , Driessen C.H. , Breunig T.M. , Marshall G.W. , Marshall S.J.
Published: January 2009

High-resolution synchrotron radiation computed tomography (SRCT) and small-angle x-ray scattering (SAXS) were performed on normal and dentinogenesis imperfecta type II (DI-1I) teeth. The SRCT showed that the mineral concentration was 33% lower on average in the DI-II dentin with respect to normal dentin. The SAXS spectra from normal dentin exhibited low-angle diffraction peaks at harmonics of 67.6 nm, consistent with nucleation and growth of the apatite phase within gaps in the collagen fibrils (intrafibrillar mineralization). In contrast, the low-angle peaks were almost non-existent in the DI-II dentin. Crystallite thickness was independent of location in both DI-II and normal dentin, although the crystallites were significantly thicker in DI-II dentin (6.8 nm [SD = 0.5] vs. 5.1 nm [SD = 0.6]). The shape factor of the crystallites, as determined by SAXS, showed a continuous progression in normal dentin from roughly one-dimensional (needle-like) near the pulp to two-dimensional (plate-like) near the dentin-enamel junction. The crystallites in DI-II dentin, on the other hand, remained needle-like throughout. The above observations are consistent with an absence of intrafibrillar mineral in DI-II dentin.
Adhesion to and Decalcification of Hydroxyapatite by Carboxylic Acids
Authors: Yoshida Y. , Van Meerbeek B. , Nakayama Y. , Yoshioka M. , Snauwaert J. , Abe Y. , Lambrechts P. , Vanherle G. , Okazaki M.
Published: January 2009

Fundamental to the processes of decalcification of or adhesion to mineralized tissues is the molecular interaction of acids with hydroxyapatite. This study was undertaken to chemically analyze the interaction of 1 mono-, 2 di-, 1 tri-, and 2 polycarboxylic acids with hydroxyapatite in an attempt to elucidate the underlying mechanism. Maleic, citric, and lactic acid decalcified hydroxyapatite, in contrast to oxalic acid and the two polycarboxylic acids that were chemically bonded to hydroxyapatite. Solubility tests showed that the calcium salts of the former were very soluble, whereas those of the latter could hardly be dissolved in the respective acid solutions. Based on these data, an adhesion/decalcification concept was advanced that predicts that carboxylic acids, regardless of concentration/pH, either adhere to or decalcify hydroxyapatite, depending on the dissolution rate of the respective calcium salts in the acid solution. This contrasting behavior of organic acids most likely results from their differential structural conformations.