bluuebunny/crossref_metadata_2025 huggingface dataset:
Caries Reduction by Milk Fluoridation in Bulgaria
Authors: Ivanova K. , Pakhomov G.N. , Moeller IJ , Vrabcheva M.
Published: January 2009

The aim of the present study has been to investigate the caries-reducing effect of a community-based milk fluoridation project. In those Kindergartens where fluoridated milk had been delivered on a regular basis, the estimated consumption corresponded to a daily intake of 200 mL milk containing 1 mg F- (5 ppm F-) for periods of 180-200 days per year. A total of 204 six-year-old children, randomly selected, was examined at baseline and three and a half years after the start of the project. A statistically significant reduction in the prevalence of dental caries was obtained for those children who had received fluoridated milk on a regular basis. In six-year-old children, the reduction in the dmft figure was 40% and in the DMFT figure, 90%. Despite the deficiencies in the design of this study (dictated by local circumstances), the results confirm the findings of other studies on the caries-reducing effect of fluoridated milk. The results also confirm that the earlier in the child's life the consumption of fluoridated milk starts, the better the effect.
The Effects of Non-Fluoridated and Fluoridated Milk on Experimental Caries in Rats
Authors: Stösser L. , Kneist S. , Grosser W.
Published: January 2009

The aim of the present investigation was to determine the caries-protective potential of non-fluoridated and fluoridated milk and to compare the efficacy of different compounds of fluoride as additives to milk. OM rats were maintained in three experiments in a frequency-controlled feeding machine of König et al. (1968) or, during one study, in metabolic cages with diet MIT 200 for three weeks. They received (1) milk with Ca-Fluoride [solubilized by KAl-Sulfate], (2) NaF, (3) NaMFP, and (4) Na-Silicofluoride. Controls were supplied with water or NaF solution of the same concentration of 10 or 15 ppm F. In addition, raw milk was provided ad libitum for the rats in a preliminary test. At the beginning and the end of the experiments, the pH of milk, its fluoride concentration, the body weight gain, the caries score, the fluoride concentration of the outermost enamel surface, the percentage of the interproximal bacteria, and the fluoride ingestion and excretion were determined. The raw milk significantly reduced the animal caries score by around 40%. This effect was lower but reproducible under programmed feeding with milk of a reduced fatty content (1.5%). The addition of Ca-Fluoride, which was not totally ionized (6.5 ppm F), reduced the caries score again by
Fluoridated Salt in France
Authors: Hescot P. , Roland E. , Desfontaine J.
Published: January 2009

Since November 28, 1985, fluoridated salt at a concentration of 250 mg KF per Kg has been authorized in food in France. It was introduced in the market at the end of 1986 and represented, in 1993, more than 60% of the market of salt. The effect of this Public Health measure will be shown. The efficiency is evaluated in epidemiological studies concerning DMF in the whole of France and in terms of safety by measurement of urinary excretion of fluoride in children who consume potassium fluoride in the salt and fluoride tablets. Last, the prevention policy in France will be described, including the use of fluoridated salt.
Strategies in the Design of Preventive Programs
Authors: Fejerskov O.
Published: January 2009

Dental caries is mostly recorded at the cavity level only. A reduced mean number of cavities in new age cohorts is often thought of as a result of prevention of the disease, dental caries. However, what is measured is rather our success in controlling the disease in such a way that prevalence of its more severe manifestations (cavities) can be reduced in children. Caries lesions and periodontal breakdown are cumulative with age and progress steadily in all populations. Thus, caries is the predominant reason for tooth loss in almost all age groups. The low prevalence and skewed distribution of dental caries make several fluoride programs less (if at all) cost-effective. Rather than considering a "whole population strategy" as opposed to a "high-risk strategy", it is argued that they should go hand in hand. However, the high-risk strategy may appear to have an unfavorable ratio of benefits to costs. So far the available literature shows no evidence that we have tests which, with sufficient predictive power, can identify groups or individuals of "high risk". It is therefore concluded that a population strategy should be maintained and further developed with emphasis on oral hygiene, because it influences norms and behavior. More knowledge about the pathogenesis of oral disease is needed before we can develop truly cost-effective strategies for the prevention of caries and periodontal breakdown.
Quality Assurance in Prevention
Authors: Edhag O.
Published: January 2009

The successful prevention of caries in Sweden, as in many other countries, is an example of what might he obtained when a systematic and complete program is adopted. Fluoride programs, mechanical cleaning of the teeth, and improved nutrition and eating habits have been the most important fundamentals for the positive results. A diminished use of tobacco, with a reduced frequency of periodontitis as one of the consequences, has been successful in some groups in the population but less so in others.

There is, however, evidence now in Sweden of a less active preventive approach concerning caries prophylaxis among some parents today than a generation ago. Thus, there are obvious reasons to continue with oral preventive programs, preferably integrated with general health programs.

For acceptable quality in preventive programs to be obtained, concrete goals must be formulated. These should be based upon scientific findings. Those in the society who should be given priority in the program must be identified by epidemiological studies. Systems for follow-up of the preventive measures should be integrated into the programs when they are initiated.

Total quality assurance programs should include parameters which describe the resources and the process needed to obtain the formulated goals. The qualifications of those involved in the process are among the most important resources for success.
The Public's Oral Health: The Gaps Between What we Know and What we Practice
Authors: Horowitz A.M.
Published: January 2009

Health for All by the Year 2000 is a theme developed in 1979 by the World Health Organization. The theme includes oral health and is being promoted throughout the world. The advances in dental research make it possible to improve oral health and, concomitantly, general health. With the appropriate use of science-based, preventive regimens, dental caries and periodontal diseases can be prevented or controlled. Further, major risk factors for oral and lip cancer are known; thus, it is possible to reduce the incidence of these diseases. Available technologies, however, are useful only when they are used by appropriate user groups as recommended. The gaps between what is known about preventing oral diseases and what is practiced are often extensive. This presentation explores differences between scientific knowledge about risk factors for oral diseases and preventive regimens and procedures, public and professional knowledge and practices, and professional support for improved oral health through the application of primary preventive procedures, often referred to as "science transfer". Barriers to the adoption of preventive regimens and practices are discussed. Strategies using health education and health promotion for narrowing these gaps are presented.
The Application of in Vitro Models to Research on Demineralization and Remineralization of the Teeth
Authors: White D.J.
Published: January 2009

Progress in in vivo and in situ experimentation has led many researchers to speculate as to the relevance and importance of in vitro testing protocols in caries research. A Medline/Biosis search for the present review revealed well over 300 citations (since 1989) documenting in vitro tests associated with caries research on mineralization and fluoride reactivity. The present survey documents these recent applications of in vitro test methods in both mechanistic and 'profile'* caries research. In mechanistic studies, in vitro protocols over the past five years have made possible detailed studies of dynamics occurring in mineral loss and gain from dental tissues and the reaction dynamics associated with fluoride anticaries activity. Similarly, in profile applications, in vitro protocols make possible the inexpensive and rapid-yet sensitive-assessment of F anticaries efficacy within fluoride-active systems, and these tests represent a key component of product activity confirmation. The ability to carry out single variable experiments under highly controlled conditions remains a key advantage in in vitro experimentation, and will likely drive even further utilization, as advances continue in physical-chemical and analytical techniques for substrate analysis in these protocols. Despite their advantages, in vitro testing protocols have significant limitations, most particularly related to their inability to simulate the complex biological processes involved in caries.
The Application of in Vitro Models to Research on Demineralization and Remineralization of the Teeth: Reaction Paper
Authors: Arends J.
Published: January 2009

Despite the advantages of in situ model studies, in vitro models are most important to provide insight into the mechanism of dental caries, the mechanisms of fluoride action, and profile screening.

In this reaction paper following Dr. White's review, the emphasis is, first, on the role of mobile fluoride (FL) in fluoride efficacy, the formation of "CaF2-like" material as fluoride reaction product, and on fluoride reaction product localization. Second, mineral assessment techniques are discussed. Finally, the main differences between caries lesion formation in vitro and in situ are considered.
The Role of Microbiology in Models of Dental Caries: Reaction Paper
Authors: Bowden G.H.
Published: January 2009

Models of the caries process have made significant contributions toward defining the roles of bacteria in caries. Microbiologists use a variety of in vitro systems to model aspects of the caries process. Also, in situ models in humans provide information on the microbiology of caries in vivo. These models do not involve the entire process leading to natural caries; consequently, the results from such studies are used to deduce the roles of bacteria in natural caries. Therefore, they can be described as Inferential Caries Models. In contrast, animal models and some clinical trials in humans involve natural caries and can be described as Complete Caries Models. Furthermore, these models are used in two distinct ways. They can be used as Exploratory Models to explore different aspects of the caries process, or as Test Models to determine the effects of anticaries agents. This dichotomy in approach to the use of caries models results in modification of the models to suit a particular role. For example, if we consider Exploratory Models, the in situ appliance in humans is superior to others for analyzing the microbiology of plaque development and demineralization in vivo. The chemostat and biofilm models are excellent for exploring factors influencing bacterial interactions. Both models can also be used as Test Models. The in situ model has been used to test the effects of fluoride on the microflora and demineralization, while the chemostat and biofilm models allow for the testing of antibacterial agents. Each model has its advantages and disadvantages and role in analysis of the caries process. Selection of the model depends on the scientific question posed and the limitations imposed by the conditions available for the study.
What is Known About Caries in Relation to Restorations as a Reason for Replacement? a Review
Authors: Ozer L. , Thylstrup A.
Published: January 2009

In the past 20 years, a great many studies have identified secondary caries to be the most common reason for the replacement of restorations. This review raises the question whether clinicians use 'secondary caries' as a catch-all into which they put a variety of reasons for replacement, or whether they do have professionally based reasons for focusing on caries adjacent to restorations. There is no consensus among researchers concerning the nature of secondary caries, but it is possible to identify two major-and conflicting-trends : One adheres to a critical approach concerning the frequency of replacements and recommends a much more conservative evaluation of existing fillings. In contrast, the other trend focuses on the clinical undetectable microleakage as the major risk factor for the initiation and uncontrolled dentinal spread of secondary caries. Since the latter trend offers a reasonable explanation for the clinicians' concern about invisible 'secondary caries', and hence reinforces the tendency to replacement, it is relevant to reconsider the conventional concept that microleakage leads to the initiation of secondary caries.

Available data indicate that visible gaps and marginal discrepancies are poorly related to secondary caries, and that secondary caries is a localized phenomenon caused by localized conditions for the evolution of cariogenic plaque. Consequently, secondary caries is not a universal attack along the entire interface between tooth and restoration, but rather a new lesion or a re-beginning of caries on the surface due to local conditions for plaque formation with cariogenic potential.

It is concluded that reinforcement of a new and more appropriate professional behavior should be based on diffusion of existing knowledge of dental caries as a disease rather than on simplified criteria for the placement and replacement of dental restorations.
Calculus-Inhibition Agents: a Review of Recent Clinical Trials
Authors: Adams D.
Published: January 2009

Clinical trials of anticalculus agents in dentifrices published since 1989 have been reviewed. There are several methods for assessment of the growth of calculus, but the most widely applied is the Volpe-Manhold scoring method .

The crystal growth inhibitors, pyrophosphate and zinc citrate, have received the greatest attention in trials of anticalculus agents. Prolongation of their activity in the mouth after teeth were brushed with the toothpaste has been sought by the use of materials which themselves have substantivity, or by the inclusion of other agents which will convey substantivity to the active ingredient. The copolymer of polyvinylmethyl ether and maleic acid anhydride has been found to increase the anticalculus efficacy of pyrophosphates, and it appears also to increase the retention of an antimicrobial, Triclosan, in plaque.

The anticalculus activity of zinc is enhanced when combined with the antimicrobial Triclosan. Trials have demonstrated a retention of anticalculus and anticaries activity when fluorides are incorporated with pyrophosphate or zinc citrate in a dentifrice. Thus, dentifrices can be formulated to offer "total" oral health care.

The newer dentifrice preparations containing an anticalculus agent with baking soda have been the subject of several trials which suggest that baking soda does not interfere with the activity of the anticalculus agents.

The association between calculus and disease is far from clear, but there is evidence that calculus, both sub- and supragingivally, may be linked to gingival recession in heavy-calculus-formers. More research is needed to clarify the role of supragingival calculus in periodontal diseases.
Calcium Salt Precipitation and Mechanisms of Inhibition Under Oral Conditions
Authors: Ingram G.S. , Edgar W.M.
Published: January 2009

Dental calculus contains a range of calcium phosphates, derived from plaque fluid and the saliva. Older deposits tend to contain more hydroxyapatite and 6 tricalcium phosphate. Compounds which inhibit the transformation of calcium phosphate nuclei to hydroxyapatite and its subsequent crystal growth are known to be effective in restricting calculus deposition in vivo. Such compounds include the diphosphonates, polyphosphates, and zinc. Under physiological conditions, apatites tend to be calcium-deficient with matching HP042- groups. If these groups are displaced, then crystal growth is inhibited. This can be demonstrated for heated apatite and FP032- treatment. The latter, however, subsequently hydrolyzes with reformation of the HPO42- groups. Diphosphonates and polyphosphates adsorb upon nuclei, displacing surface phosphate in the process. The treated apatite nuclei will not grow until the adsorbed species are displaced or hydrolyzed. The cationic inhibitor, zinc, is acquired by the dental plaque and oral surfaces and is eluted in the saliva. Zinc is adsorbed upon apatite crystallites with displacement of calcium. When a surface coverage of approximately 3 μmol/m2 is achieved, crystal growth is almost completely inhibited. Post-treatment with calcium desorbs the zinc. Inhibition of hydroxyapatite crystal growth and thence calculus formation thus depends upon displacement of surface ions from seed crystallites. The role of HPO42- groups in this and other physiological apatite processes is of particular interest.
The Use of Whole Saliva in the Differential Diagnosis of Sjögren's Syndrome
Authors: Sreebny L.M. , Zhu W.X.
Published: January 2009

Sjögren's Syndrome (SS) is a chronic, multisystem. autoimmune disorder. It is characterized by (1) generalized exocrine gland dysfunction, (2) serologic abnormalities, and (3) organ-system changes. Oral changes are a prominent feature of this disease. Among these are xerostomia and hypofunction of the salivary glands. Given the intimate relationship between SS and the salivary glands, it is reasonable to postulate that whole saliva (WS) contains the stigmata associated with the presence of this disease. But few studies have been conducted on this secretion. Indeed, WS has largely been neglected and ignored by physicians, dentists, and scientists. Objections to its use have included the fact that it is "impure", that it does not adequately represent what is present in the salivary glands, that no standards have been established for its rate of flow, and that findings based on it lack specificity. Yet, it is this secretion which coats and protects the hard and soft oral tissues, enables us to prepare our food for digestion, and assists our speech.

This review will demonstrate that there is a uniqueness and constancy to whole saliva and that it may be used to diagnose the presence of SS. "Screening tests", which include several simple-to-perform sialometric, chemical, and microbiologic procedures, may be conducted in doctors' offices to establish the "profile" of an SS patient. Electrophoretic studies may be used to study the nature of the salivary proteins, and an immunologic test, which is performed on WS and utilizes Western Blot Autoantibody Strips (ImmunoVision. Springdale, AR). may be used to establish the definitive diagnosis of SS.
Current Treatment Modalities of Oral Problems of Patients with Sjögren's Syndrome: Caries Prevention
Authors: Newbrun E.
Published: January 2009

Prevention of dental caries in patients with hyposalivation due to Sjogren's syndrome requires increasing host resistance and decreasing cariogenic organisms and their substrate. Although plaque control by scrupulous oral hygiene is important, particularly from a periodontal perspective, and restriction of dietary sucrose intake can limit caries, the most successful therapeutic and preventive measure has been the topical application of fluoride to the tooth surface, by the dentist, dental hygienist, dental auxiliary, and the patient. Studies on schoolchildren with normal salivary function who used fluoride dentifrices have shown that efficacy in caries prevention depends on (1) the concentration of fluoride used, (2) the frequency with which it is applied, and, to a certain extent, (3) the specific fluoride compound used. Controlled clinical studies are lacking, however, on patients with hyposalivation due to Sjogren's syndrome, and only limited data are available from patients with radiation-induced hyposalivation. Obviously it is not possible to run placebo control groups; nevertheless, there have been no head-to-head comparisons of fluoride rinses, or of stannous fluoride, acidulated phosphate fluoride, or sodium fluoride gels, and thus no single protocol can be recommended. Accordingly, different centers have used these products interchangeably—for example, selecting a rinse regimen if patients complain of gagging when using a gel applied in a tray, or if the cost of the tray is prohibitive. Recent innovations that show promise for treatment of high-caries-risk patients with hyposalivation are the use of fluoride rinses in combination with chlorhexidine rinses or gels and the professional application of high-concentration chlorhexidine varnishes to the teeth.
Sjögren's Syndrome: Clinical Spectrum and Current Diagnostic Controversies
Authors: Daniels T.E.
Published: January 2009

Although we have had a useful and internationally agreed-upon definition of Sjogren's syndrome (SS) for more than 30 years, we have not yet agreed upon criteria for diagnosing it. Understanding the clinical spectrum of SS and the various tests used to diagnose its components provides a basis for discussing controversies about diagnostic criteria. A review of the clinical features of SS and their diagnostic tests is followed by assessments of seven sets of diagnostic criteria and a proposal for future criteria. The various existing criteria use different combinations of clinical features and tests, which results in populations of different sizes and homogeneities being given the diagnosis of SS. Some criteria propose alternative tests in diagnosing components of SS, while others do not. Internationally accepted diagnostic criteria for SS that are as disease-specific as possible are needed for us to learn the epidemiology, pathogenesis, treatment, and prognosis of this clinically and scientifically important disease.
Sjögren's Syndrome: Immunobiology of Exocrine Gland Dysfunction
Authors: Fox R.I.
Published: January 2009

Sjögren's syndrome is an autoimmune disorder characterized by dryness of the eyes and mouth. The frequency of this disorder remains controversial, due to absence of a universally accepted classification system. In the San Diego and San Francisco classification systems for primary Sjogren's syndrome, evidence for an autoimmune process and focal lymphocytic infiltration of the salivary or lacrimal gland is required for diagnosis. This paper reviews the genetic and environmental factors that have been associated with the autoimmune process in Sjogren's syndrome. Key immunopathologic features include: (a) an increased prevalence of particular HLA-DR/DQ alleles; (b) induction of HLA-DR/DQ proteins on the epithelial cells in salivary and lacrimal gland biopsies; (c) infiltration of the glands by CD4+ T-cells that transcribe IL-2 and IFN--y; (d) induction of granzyme A and perforin in CD4+ T-cells, suggesting a mechanism of cellular destruction of the glands; (e) clonal expansion of B-cells that use a particular light chain within the salivary gland; (f) production of autoantibodies against nuclear antigens SS-A (60 and 52 kDa) and SS-B (48 kDa), indicating a failure of normal tolerance mechanisms; and (g) increased frequency of B-cell non-Hodgkin's lymphoma. Indirect evidence has suggested a potential role for viruses (especially members of the herpesvirus and retroviral family) as co-factors.
Immunologic Markers for Differentiation of Autoimmune Responses
Authors: Williams R.C.
Published: January 2009

Several approaches have been directed at identifying accurate parameters for the measurement of disease activity in autoimmune disorders, both in humans and in experimental animal models. A great deal of previous effort has focused on determining what constitutes antigenic epitopes on various autologous proteins or tissue components, which then can generate an immune response in the host. Much of this work has been clouded by the fact that normal subjects (both animal and human) seem to mount an immune response to myriad autologous proteins, characterized by the formation of antibodies known as natural autoantibodies. During the course of certain autoimmune diseases such as systemic lupus erythematosus (SLE) or Wegener's granulomatosis (WG), patients produce what appear to be autoantibodies reacting with autologous components such as DNA and Sm antigen (SLE) or proteinase-3 (WG). Low levels of these same autoantibodies are present in IgG derived from normal subjects. Recently, we have found that IgG anti-F(ab')2 from normal subjects, affinity-purified from immunoabsorbent columns of human F(ab_)2 Sepharose, exhibits not only anti-F(ab')2 but also anti-dsDNA and anti-Sm activity. These antibodies constitute an average of 0.02% of normal serum IgG. Similar findings have also been observed in SLE patients with active disease. Our findings suggest that perturbation of the idiotypic network may represent an important fundamental aspect of many autoimmune disorders.
Principles of Microbial Ecology and Their Application to Xerostomia-Associated Opportunistic Infections of the Oral Cavity
Authors: Hillman J.D.
Published: January 2009

The human oral flora is normally composed of hundreds of different types of bacteria. This high degree of complexity is largely responsible for the observation that a state of health is the predominant condition of the oral cavity: Myriad bacterial interactions between innocuous and potentially pathogenic species prevent the latter from attaining sufficient numbers to initiate clinically observable diseases. However, protracted or profound perturbations of the oral environment may lead to ecological upsets fundamentally characterized by extreme simplification of the resident flora. Radiation- or autoimmune-induced xerostomia is a striking example of such a perturbation. During the period of floral simplification, as the bacterial interactions diminish, impediments to the outgrowth of pathogens are lost, ultimately leading to the onset of disease.

In the absence of methods to reverse the conditions responsible for the ecological upset, as is currently the case in many forms of xerostomia, the possibility of restoring a complex, balanced flora is not imminently practical. However, as our understanding of microbial ecology and pathogenesis develops, application of a replacement therapy approach may become plausible to prevent or retard particular diseases prevalent in xerostomia patients.
Radioautographic Study of the Incorporation of (3H)-Choline Into the Phospholipids of Secretory Ameloblasts and Enamel of Normal and Essential-Fatty-Acid-Deficient Rats
Authors: Goldberg M. , Lécolle S. , Bissila-Mapahou P. , Septier D. , Carreau J.P.
Published: January 2009

(3H)-choline, a precursor for phosphatidylcholine (PC) and sphingomyelin (SM), was injected into rats killed after 4, 24, 48, and 96 hrs. Radioautography carried out on malachite-green/aldehyde-fixed tissues demonstrated that labeled choline was incorporated into cells and further released into the extracellular matrix. In predentin, labeling decreased rapidly, whereas in dentin, silver grains formed a stable band. In contrast, labeling was still high at 48 and 96 hrs in secretory ameloblasts as well as in the forming enamel. This indicates that ameloblasts are actively involved in the synthesis of membranes. Membrane remnants of the ameloblasts could be released into the forming enamel. In rats fed with an essential fatty-acid-deficient (EFAD) diet for 42 days, (3H)-choline uptake was delayed and reduced in pulp cells and odontoblasts, and consequently the migration of labeled phospholipids into dentin. The influence of the EFAD diet on secretory ameloblasts was limited. No difference was detected between normally fed and EFAD-fed rats in the forming enamel.
Lattice Fringe Continuity in the Absence of Crystal Continuity in Enamel
Authors: Dong W. , Warshawsky H.
Published: January 2009

Since high-resolution transmission electron microscopy (HRTEM) provides information on a nearly atomic level, the confidence level with this method is very high. Thus, when lattice fringe continuity is found between two enamel crystals in proximity, such continuity has been taken as evidence of crystal fusion (Daculsi and Kerebel, 1977). Similarly, selected-area dark-field (SADF) electron microscopic imaging has been used to study the axial and spatial orientation of crystals. These studies have shown that there is apparent continuity between enamel and dentin crystals (Arsenault and Robinson, 1989). This observation supported the hypothesis that enamel crystallites are initiated by crystallites in dentin. We have used both HRTEM and SADF methods to identify instances of spatial relationship between crystallites in sections of rat incisor enamel and shark enameloid. In each instance of apparent continuity, goniometric tilting was used to examine the continuous interface. All instances where two crystallites seemed to come into contact, and where HRTEM imaging showed the lattice fringes to be directly continuous, were separated into individual crystallites when the specimen was tilted a few degrees. Thus, adjacent crystallites can show lattice fringe continuity in the absence of real crystallite contact. When instances of overlapping crystallites were examined by SADF imaging, the overlapping crystallites gave a single bright image. Goniometric tilting revealed separate crystallites. Thus, neither lattice fringe continuity nor image continuity under SADF can be used as evidence of crystal continuity unless goniometric rotation and tilting are applied when spatial relationships are suspected.
Mathematical Modeling of Biofilms
Authors: Dibdin George H.
Published: January 2009

A set of mathematical equations constitutes a mathematical model if it aims to represent a real system and is based on some theory of that system's operation. On this definition, mathematical models, some very simple, are everywhere in science. A complex system like a biofilm requires modeling by numerical methods and, because of inevitable uncertainties in its theoretical basis, may not be able to make precise predictions. Nevertheless, such models almost always give new insight into the mechanisms involved, and stimulate further investigation. The way in which diffusion coefficients are measured for use in a model, particularly whether they include effects of reversible reaction, is a key element in the modeling. Reasons are given for separating diffusion from reversible reaction effects and dealing with them in a separate subroutine of the model.
The Validity of Models
Authors: Wimpenny J.W.T.
Published: January 2009

The ubiquity of biofilm and its classification as a microbial aggregate is discussed. Investigations into any microbial ecological problem operate at four levels: (i) in situ investigations, (ii) the use of microcosms, (iii) experimental model systems, and (iv) mathematical models. Each of these is defined and their use in biofilm research illustrated. It is concluded that all these approaches are valid and that scientific research in general and biofilm research in particular must profit by the use widely different methods if a complete understanding of a system is to be achieved.
Phagocyte-Bacteria Interactions
Authors: Keisari Y. , Kabha K. , Nissimov L. , Schlepper-Schafer J. , Ofek I.
Published: January 2009

Recognition and phagocytosis of microorganisms in a serum-poor environment represent innate immunity against many extracellular pathogens. As a paradigm for such processes, we discuss the recognition of Klebsiella pneumoniae by alveolar macrophages and monocyte-derived macrophages in the absence of serum. Macrophages recognize and subsequently kill Klebsiella expressing Man-a2/3-Man or Rha-a2/3-Rha sequences in their capsular polysaccharides by two mechanisms: (a) recognition of the capsular structures by macrophage mannose receptors, and (b) opsonization by the lung surfactant protein A (SP-A), which binds to the capsular polysaccharides of Klebsiella and to SP-A receptors on the macrophages. Sp-A may also enhance phagocytosis by increasing the activity of macrophage mannose receptors. We conclude that a specific microbial surface structure may be a target for recognition by macrophages via several mechanisms, as exemplified in the case of Klebsiella capsular polysaccharides. Multiple recognition mechanisms of pathogens by macrophages may be essential to provide innate immunity to reduce the frequency of infections caused by a relatively less virulent bacterium in the immunocompromised host.
ICS-II USA Research Locations: Environmental, Dental Care Delivery System, and Population Sociodemographic Characteristics
Authors: Reifel N.M. , Davidson P.L. , Rana H. , Nakazono T.T.
Published: January 2009

Secondary data sources are used to describe the ICS-II USA research locations in terms of external environment, dental care delivery system, and population sociodemographics. The Native American reservations located in Arizona, New Mexico, and South Dakota were rural, while the other research locations were primarily urban. Baltimore, Maryland, and the Native American communities had fluoridated water, but San Antonio did not. Dental services in Baltimore and San Antonio were predominantly financed by private sources, with a small public health component. Dental care services in Native American communities were largely Indian Health Services (IHS) financed by the US Government. Each geographical area exhibited diverse characteristics indicating unique challenges for the delivery of community and clinical dental services.
Predisposing, Enabling, and Need for Dental Treatment Characteristics of ICS-II USA Ethnically Diverse Groups
Authors: Atchison K.A. , Davidson P.L. , Nakazono T.T.
Published: January 2009

Personal characteristics (predisposing, enabling, and need) are described for the population-based samples of adults interviewed in the International Collaborative Study of Oral Health Outcomes (ICS-II) USA research locations. Differences in sample characteristics are compared by ethnic group (African-American, Native American, Hispanic, and White) and age cohort (35-44 and 65-74 years old) by means of Bonferroni multiple-means tests and Student's t tests. Differences in the personal characteristics of these diverse comparison groups abound. Bivariate results indicated that White adults from both age cohorts had higher socio-economic levels, more positive self-rated health status, and greater proportions of individuals with dental benefits. Lakota adults from both age cohorts reported lower self-rated health status and were most likely to report total tooth loss. Hispanic persons were significantly less likely to report a usual source of dental care or dental benefits. Need for dental treatment (oral pain and oral symptoms index) was generally higher among Native American and Hispanic groups. It is critical that the differences highlighted between and among these groups be studied if appropriate strategies for improving the oral health of USA adults are to be determined.
Clinical Measures and Treatment Needs
Authors: Marcus M. , Reifel N.M. , Nakazono T.T.
Published: January 2009

Clinically evaluated oral health outcome variables from the ICS-II USA data set were examined in the diverse ethnic groups, for two adult age cohorts (35-44 and 65-74 years). These measures were derived from epidemiological examinations and include the DMFT components, loss of attachment, and an indicator of treatment need-the ratio of decayed teeth over decayed and filled teeth. The ratio of decayed over decayed and filled teeth was used in multivariate analysis, since this measure represents an area where public policy could have an impact if determinants were understood. The most important independent variables were race-ethnicity, educational attainment, no fear of dental visits because of pain, and oral hygiene practices. Having a usual source of dental care and visiting the dentist within the past 12 months did not appear to be as important in predicting unmet needs as these other variables. To bridge the gap between the oral health status of majority and minority populations, health educators in minority communities need to become more accessible, have a pro-active interest in oral health, and also be cognizant of the various socio-cultural issues influencing oral health. The problems regarding Native American adults are more complex and require more careful study.
Perceived Oral Health in a Diverse Sample
Authors: Atchison K.A. , Gift H.C.
Published: January 2009

Measures of perceived oral health represent subjective, individual perspectives of one's health. One measure commonly used is the single-item perceived oral health rating: How would you rate your overall oral health? These analyses examine the associations among age, ethnicity, and perceived oral health within the context of a comprehensive battery of 21 predisposing, enabling, and need variables. The study compares the adult data from three United States research locations of the International Collaborative Study of Oral Health Outcomes (ICS-II). Only social survey data were used for this analysis. The multiple regression model explains over 30% of the variance in perceived oral health, with R squares ranging from 0.324 for Indian Health Service sites to 0.391 for San Antonio. The most important significant predictors include ethnic group, education, perceived general health status, being edentulous or not having a partial denture, having no oral pain, fewer oral symptoms, and having one or more dental visits. The predictors of positive perceived oral health for the diverse groups highlight interesting age and ethnic differences. The only universal predictor for the middle-aged adults was having fewer oral symptoms. For the older adults, being edentulous or not having a partial denture was the only universal predictor. The findings suggest that perceived oral health may be a useful outcome measure in dentistry because of its relation to predisposing sociodemographics and dental utilization.
Consumer Satisfaction
Authors: Reifel N.M. , Rana H. , Marcus M.
Published: January 2009

Patient satisfaction with dental care is compared across six United States groups: Whites in Baltimore and San Antonio, African-Americans in Baltimore, Hispanics in San Antonio, and Native Americans in the Southwest and the Dakotas. First, differences in patient satisfaction across ethnic groups and between two age groups (65-74 years old and 35-44 years old) are considered. Generally, people from all age and ethnic groups were satisfied with the last dental visit. Second, patient satisfaction is conceptualized as an oral health outcome influenced by characteristics of the dental service utilizer: predisposing sociodemographic characteristics, predisposing oral beliefs, enabling characteristics, oral needs, oral health behaviors, and oral health status. Multivariate analyses by age and ethnic group are used to identify characteristics that influence patient satisfaction. Sociodemographic characteristics were important among the elderly. Strong oral health beliefs influenced patient satisfaction among younger adults. Enabling characteristics were important predictors among the Native American groups. This model explained 15%-30% of the variability in patient satisfaction among the study age and ethnic groups.
Prevention and Treatment of Smokeless Tobacco Use
Authors: Hatsukami D.K. , Boyle R.G.
Published: January 2009

A review of the literature examining school-based prevention and treatment intervention programs for smokeless tobacco users is provided. Although few school-based prevention studies have been conducted, the results are promising. Many of the treatment studies that have been conducted, thus far, are limited due to the sample size and the lack of a control group. However, of the studies that have not had these limitations, the results are also promising. In general, studies show that intervention in the dental office can be effective and that group behavioral treatment may also improve cessation rates over minimal contact. On the other hand, pharmacological treatment, which has primarily focused on 2 mg nicotine gum, has not been found to be an effective treatment. Dentists are in an ideal position to advise and assist smokeless tobacco users to quit. The majority of smokeless tobacco users want advice and help from their dentists, and a significant number indicate that discussion of the negative oral effects from the use of smokeless tobacco has an impact on their desire to quit.
In Vivo Detection of Calcium from Dicalcium Phosphate Dihydrate Dentifrices in Demineralized Human Enamel and Plaque
Authors: Sullivan R.J. , Charig A. , Blake-Haskins J. , Zhang Y.P. , Miller S.M. , Strannick M. , Gaffar A. , Margolis H.C.
Published: January 2009

A series of studies was conducted to clarify the role of DCPD in improving the effects of fluoride in the mouth. We performed plaque fluid studies to see if the use of DCPD dentifrices increases the levels of free Ca2+ ions and the DSenamel in plaque fluid. The results of these studies showed that plaque fluid was undersaturated with respect to DCPD; therefore, DCPD would dissolve in the mouth. The Ca2+ activity in plaque fluid measured 12 hours post-treatment was significantly elevated with the use of DCPD dentifrices in comparison with silica dentifrices. The use of DCPD dentifrices also increased the DSenamel of plaque fluid in comparison with a NaF/silica dentifrice. To determine whether Ca from DCPD could be detected in demineralized enamel and whole plaque after in vivo usage of a DCPD/ fluoride dentifrice, we conducted a 44Ca labeling study. Secondary Ion Mass Spectrometry (SIMS) was used to detect and measure changes in 44Ca levels in enamel before and after 6 days of in vivo treatment with a 44DCPD/fluoride dentifrice. The results showed that 44Ca from DCPD was incorporated into enamel and detected in plaque 18 hours post-treatment. The findings from these studies show that brushing with a DCPD dentifrice introduces additional, exogenous Ca into the oral environment, which fosters improved remineralization of teeth in combination with fluoride.
Major Topics in Quantitative Microradiography of Enamel and Dentin: R Parameter, Mineral Distribution Visualization, and Hyper-Remineralization
Authors: Arends J. , Ruben J.L. , Inaba D.
Published: January 2009

Three aspects of quantitative transverse microradiography are described and discussed: (1) the average mineral loss parameter of enamel or dentin lesions (R) in vol%; (2) mineral distribution visualization of lesions by means of a computer-assisted videodensitometric (CAV) method; and (3) the microradiography of hyper-remineralized lesions. "R", defined as the average amount of mineral lost (or gained) in a lesion per unit lesion length, is a useful parameter in dental caries. The results show that, in vitro, R is about constant over the demineralization period for enamel and dentin. This was found even for quite different dissolution kinetics. R is strongly reduced by the presence of small amounts of fluoride in the demineralizing system. R of dentin lesions is smaller than for enamel lesions. We conclude that the mineral loss value (ΔZ) and the lesion depth (ld) are in general dependent parameters during in vitro or in situ studies on enamel or dentin. During lesion formation, mineral loss from the lesion and acid penetration in the tissue are obviously linked. This is possible only if the mineral content in the lesion does not change very much after passage of the lesion front. The CAV method presented is illustrated for enamel lesions formed in vitro and in situ.
Reproducibility of TMR for the Determination of Longitudinal Mineral Changes in Dental Hard Tissues
Authors: Damen J.J.M. , Exterkate R.A.M. , Ten Cate J.M.
Published: January 2009

Transverse microradiography (TMR) of thin sections is the principal method for determining mineral changes in experimental lesions. Because it has become also the standard by which newly-developed methods are validated, demands on all steps of the procedure are high. Thin sections of enamel and dentin require high-precision cutting or lapping to preserve surface structures, but their different brittleness and elasticity preclude a uniform procedure. Image analysis permits the measurement of fine details at a μm scale, but because most studies are aimed at overall mineral changes, they are usually lost on broadening of the scan areas and averaging of experimental groups. Small errors in repositioning of the scan areas for repetitive measurements may yield distorted lesion profiles, while quantitative data such as the integrated mineral loss are hardly influenced. A major reason for "irreproducibility" of TMR are the different definitions of the lesion parameters as used by various research groups. We recommend that these definitions be agreed on if the full potential of TMR as an international standard is to be utilized.
Electron Probe Microanalysis and Transverse Microradiography Studies of Artificial Lesions in Enamel and Dentin: A Comparative Study
Authors: Ngo H. , Ruben J. , Arends J. , White D. , Mount G.J. , Peters M.C.R.B. , Faller R.V. , Pfarrer A.
Published: January 2009

In cariology and research involving the interactions between restorative materials and dental hard tissues, it is important for small changes in tooth mineral content to be measurable. Currently, transverse microradiography (TMR) is the most accepted tool for the above purpose. Electron Probe Microanalysis (EPMA) can yield both qualitative identification of elements and quantitative compositional information. The purpose of this study was to compare the mineral distribution in well-defined artificial lesions, in dentin and enamel, by the use of both TMR and EPMA on the same sample. The good correlation between the two sets of data validates EPMA as a technique and helps in the interpretation of its results. The data from TMR analysis are expressed as vol% of mineral, while EPMA gives the levels of Ca and phosphate in wt%. The conversion between the two sets of data is complicated by the fact that local density is, as yet, unknown.
Caries Development in Fluoridated and Non-Fluoridated Deciduous and Permanent Enamel in Situ Examined by Microradiography and Confocal Laser Scanning Microscopy
Authors: Sønju Clasen A.B. , Øgaard B. , Duschner H. , Ruben J. , Arends J. , Sönju T.
Published: January 2009

The aim of the study was to compare initial caries development in fluoridated and non-fluoridated deciduous and permanent enamel in situ. Enamel slabs were mounted in removable appliances and worn for 4 wks. Significantly larger lesions developed in deciduous than in permanent enamel when no topical fluorides were used. Fluoride mouthrinsing partly prevented lesion development in deciduous and completely in permanent enamel. Initial enamel caries not detected by microradiography can be visualized by CLSM (confocal laser scanning microscopy).