Abstract：
:Cultures of Streptococcus mutans MFe28 (serotype h) were grown with differing extracellular polysaccharide (EPS) content. Biochemical and physicochemical characteristics considered relevant to caries were measured. Acid production parameters measured in a pH-stat were: Vm = 0.76 +/- 0.14 mumol/g/sec (wet weight); apparent Km (acid production) = 100 mumol/L; molar yield = 1.97 +/- 0.25 mol acid/mol glucose. Acid anion inhibition of acid production was also noted. Buffering by the pure washed bacterial residue required approx. 112 mumol of base/g (wet weight) of residue to change the pH from 4 to 6.5, and this dropped almost to zero as the EPS content increased to 100%. Diffusion coefficients (D) in the residues were independent of EPS content over a wide range. When the effusion method was used, De (glucose) and De (acetate) were (3.26 +/- 0.6) and (5.05 +/- 0.8) x 10(-6) cm2/sec, respectively. The extracellular fluid fraction, measured by inulin exclusion, increased from 0.33 for the pure bacteria to 0.78 for the pure EPS. It is shown how, by these factors alone, and without any need for diffusion restriction, plaque EPS may lead to a lower pH at the tooth surface, thus increasing the cariogenic challenge.
journal_name
J Dent Resjournal_title
Journal of dental researchauthors
Dibdin GH,Shellis RPdoi
10.1177/00220345880670060101subject
Has Abstractpub_date
1988-06-01 00:00:00pages
890-5issue
6eissn
0022-0345issn
1544-0591journal_volume
67pub_type
杂志文章abstract：:The etiology and pathogenesis of craniofacial birth defects are multifactorial and include both genetic and environmental factors. Despite the identification of numerous genes associated with congenital craniofacial anomalies, our understanding of their etiology remains incomplete, and many affected individuals have a...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034520969109
更新日期：2020-11-06 00:00:00
abstract：:Intracystic fluid pressure is thought to be involved in odontogenic cyst growth. In this study, we investigated the effects of positive pressure on the expression of interleukin-1alpha (IL-1alpha), matrix metalloproteinases (MMPs), and prostaglandin E2 (PGE2) in odontogenic keratocysts to determine whether this pressu...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910508401008
更新日期：2005-10-01 00:00:00
abstract：:The relationship between periodontitis and systemic bone mineral density in Japanese women is undetermined. We tested the hypothesis that periodontitis was more frequent in women with low metacarpal bone mineral density (m-BMD). Subjects were 190 Japanese women (89 premenopausal, 101 post-menopausal). Periodontal stat...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345010800090901
更新日期：2001-09-01 00:00:00
abstract：:Previous studies showed that residual compressive stresses induced by thermal tempering retarded the growth of surface cracks in bilayered porcelain disks. The objectives of the present study were: (1) to determine whether thermal tempering by air blasting reduces the length of cracks induced by microhardness indentat...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345960750020301
更新日期：1996-02-01 00:00:00
abstract：:The purpose of this investigation was to determine the water sorption and solubility, as well as the filler composition and extent of chemical degradation in water, of eight different posterior composites. With one exception, the materials with the largest quantity of fillers had the least water sorption and solubilit...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345860650110601
更新日期：1986-11-01 00:00:00
abstract：:The aim of this study was to test the hypothesis that the chewing of xylitol- or xylitol/sorbitol-containing chewing gum reduces plaque formation and the acidogenic potential of dental plaque. Thirty healthy volunteers aged from 19 to 28 yrs were randomly allocated to one of three test groups, chewing either xylitol-,...
journal_title：Journal of dental research
pub_type： 临床试验,杂志文章,随机对照试验
doi：10.1177/00220345980770071001
更新日期：1998-07-01 00:00:00
abstract：:The aim of this study was to compare the effectiveness of dexamethasone administration following arthrocentesis of the temporomandibular joint (TMJ) with a placebo (saline). Twenty-eight participants with TMJ arthralgia were randomly assigned to two groups of a parallel double-blind RCT. In both groups, an arthrocente...
journal_title：Journal of dental research
pub_type： 杂志文章,随机对照试验
doi：10.1177/0022034511431260
更新日期：2012-02-01 00:00:00
abstract：:The experiment was designed to determine the pathway taken to the brain stem by periodontal afferents responsible for the digastric jaw-opening reflex induced by tooth-tapping. Cutting the trigeminal sensory roots of anesthetized decerebrate cats eliminated the ipsilateral periodontally-induced reflex, although the st...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345870660100401
更新日期：1987-10-01 00:00:00
abstract：:Mixed or parotid saliva from caries-active individuals consistently supported better growth of Streptococcus mutans (type c) than that from caries-free individuals. Electrophoretic studies revealed that certain proteins in caries-active salivas were susceptible to microbial attack, but similar proteins in caries-free ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345790580101501
更新日期：1979-10-01 00:00:00
abstract：:Radiation therapy for head and neck cancer results in severe secondary side-effects in salivary glands. We previously demonstrated that the administration of IGF1 preserves or restores salivary gland function following radiation. Based on these findings, we propose to study the effect of IGF1 on human head and neck ca...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034510388037
更新日期：2011-03-01 00:00:00
abstract：:Indigenous populations around the world experience a disproportionate burden in terms of oral diseases and conditions. These inequalities are likely due to a complex web of social determinants that includes poverty, historical consequences of colonialism, social exclusion, government policies of assimilation, cultural...
journal_title：Journal of dental research
pub_type： 杂志文章,评审
doi：10.1177/0022034518763605
更新日期：2018-07-01 00:00:00
abstract：:Eighteen different Streptococcus strains including S mutans, sanguis, mitis, salivarius, bovis, and 2F2, were assayed for their relative adsorption to synthetic hydroxyapatite and for quantities of lactic acid produced while in the adsorbed state. The results indicated that all S mutans and some S sanguis have an enha...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345770560101401
更新日期：1977-10-01 00:00:00
abstract：:Monolayers of feline parotid acinar cells were infected with feline rhinotracheitis herpes virus. Membrane potentials and input resistances were measured before and during infection. Uninfected acinar cells had an average membrane potential of -51 mV and resistances from 6 to 120 mega-ohms; cells infected for more tha...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345810600121001
更新日期：1981-12-01 00:00:00
abstract：:Enamel crystals in the demineralized zones in early caries lesions of human teeth were observed by high-resolution electron microscopy. The enamel crystals frequently exhibited perforations in their centers and defects of various sizes on their lateral surfaces. There were a number of small electron-lucent spots, sugg...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345870660110901
更新日期：1987-11-01 00:00:00
abstract：:A sintered hydroxyapatite (HAP) ceramic for use in wear studies was prepared from a commercial tricalcium phosphate. The sintered HAP had physical properties close to those of human enamel. The coefficient of friction and wear of the sintered HAP ceramic as characterized by tangential force, track width, and surface f...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345780570070401
更新日期：1978-07-01 00:00:00
abstract：:The periodontal ligament (PDL) works as a suspensory ligament when external mechanical stress is placed on the teeth. PDL fibroblasts, the principal cells in the PDL, are responsible for many PDL functions. We hypothesized that mechanosensitive ion channels are present in human PDL fibroblasts, which are capable of re...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910608500716
更新日期：2006-07-01 00:00:00
abstract：:A numerical model of the mandible, its articulating surfaces, and the forces exerted by the primary masticatory muscles has been developed for the purpose of investigating loading of the temporomandibular joint. Evidence is presented which shows that the temporomandibular joint. Evidence is presented which shows that ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345860650080201
更新日期：1986-08-01 00:00:00
abstract：:Wall-to-wall (WTW) polymerization contraction of filled and unfilled chemically and photo-initiated resins was studied in relation to the WTW distance. In an experimental set-up, the resins were bonded to two opposing disks, and the axial (WTW) displacement resulting from the polymerization shrinkage was measured cont...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345890680010701
更新日期：1989-01-01 00:00:00
abstract：UNLABELLED:The aim of this observational study was to investigate the features of the chewing activity and the variability of the human chewing pace, as assessed in the natural environment. It was hypothesized that the chewing pace is relatively constant within individuals across different days but is variable across i...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034511416669
更新日期：2011-10-01 00:00:00
abstract：:A method of articulator comparison and a technique demonstrating the effects of three occlusal determinants were demonstrated and proved successful. The techniques used could be used in dental research circumstances and in dental schools as a means to study the determinants of occlusion. ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345760550060601
更新日期：1976-11-01 00:00:00
abstract：:Soft lining materials undergo two processes when immersed in water. Plasticizers and other soluble materials are leached into the water, and water is absorbed by the polymer. The balance between these two processes affects both the compliance and dimensional stability of the materials. ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345830620061601
更新日期：1983-06-01 00:00:00
abstract：:We analyzed the flow rate and composition of paraffin-stimulated whole saliva samples from 35 adult diabetic patients and their age- and sex-matched, non-diabetic, clinically healthy controls. All patients had insulin-dependent diabetes (IDDM) with a mean (+/- S.D.) duration of 14.0 +/- 9.1 years. The saliva analysis ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345860650011101
更新日期：1986-01-01 00:00:00
abstract：:The junctional epithelium (JE) is unique with regard to its wide intercellular spaces and sparsely developed intercellular junctions. Thus, knowledge of the molecular mechanisms that regulate the formation of the intercellular junctions of the junctional epithelium may be essential to understand the pathophysiology of...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034515619375
更新日期：2016-03-01 00:00:00
abstract：:Periodontal inflammation and alveolar bone remodeling during orthodontic tooth movement are considered regional reactions. However, how systemic immune responses are involved in this regional reaction remains unclear. In this study, we explored the systemic effects of orthodontic force by focusing on the mononuclear p...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034515592868
更新日期：2015-09-01 00:00:00
abstract：:Changes in stimulated and non-stimulated whole saliva flow rates were measured in 11 Hodgkin's disease patients who received therapeutic doses of radiation to a mantle field at the M. D. Anderson Hospital in Houston, Texas. Salivary flow rates were examined before, during, and after radiotherapy. Mean flow rate reduct...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345880670021801
更新日期：1988-02-01 00:00:00
abstract：:One-step incomplete excavation seals caries-affected dentin under a restoration and appears to be advantageous in the treatment of deep lesions. However, it is impossible to discriminate radiographically between intentionally left, arrested lesions and overlooked or active lesions. This diagnostic uncertainty decrease...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034514531291
更新日期：2014-06-01 00:00:00
abstract：:Odontoblasts, with their strategic arrangement along the outermost compartment of the dentin-pulp complex, have been suggested to have sensory function. In addition to their primary role in dentin formation, growing evidence shows that odontoblasts are capable of sensing mechanical stimulation. Previously, we found th...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034518759947
更新日期：2018-08-01 00:00:00
abstract：:The dental follicle (DF) differentiates into the periodontal ligament. In addition, it may be the precursor of other cells of the periodontium, including osteoblasts and cementoblasts. We hypothesized that stem cells may be present in the DF and be capable of differentiating into cells of the periodontium. Stem cells ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910808700801
更新日期：2008-08-01 00:00:00
abstract：:Genetic approaches are rapidly yielding new information about our sense of taste. This information comes from both molecular studies of genes encoding taste receptors and other taste-signaling components, and from studies of inherited variation in taste abilities. Our understanding of bitter taste has advanced by comb...
journal_title：Journal of dental research
pub_type： 杂志文章,评审
doi：10.1177/154405910408300603
更新日期：2004-06-01 00:00:00
abstract：:Strength and durability of the dentin-acrylic resin joint cemented with 2-cyanoacrylate esters were studied. Maximum adhesion is obtained with isobutyl 2-cyanoacrylate after 1% acid pretreatment of the dentin. Hydrolytic stability is somewhat improved by addition of polymer to the adhesive or coating around the joint....
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345790580090901
更新日期：1979-09-01 00:00:00
