Abstract：
:Evaluation of long-term mechanical behavior of new types of restorations in clinical trials is time-consuming. A partial alternative can be found in experimental fatigue-testing, which simulates accelerated mechanical deterioration. The aim of this study was to determine the feasibility of using fatigue-testing of a complex dental restoration and to evaluate the mechanical fatigue behavior of premolar teeth restored with a titanium alloy post and an amalgam or composite core. Eighty-seven human upper premolar teeth were decoronated, embedded, and restored with a prefabricated post of 1 mm diameter. The teeth were randomly assigned to one of two groups corresponding with a core build-up of amalgam or chemically-cured core composite, respectively. Five to 21 days after restoration, the specimens were subjected to cyclic loading (frequency, 5 Hz), at an angle of 45 degrees to the long axis of the tooth. The boundary technique was used for determination of the mean fatigue strengths of the restorations at 10(4), 10(5), and 10(6) cycles, simulating up to 1-3 years of clinical functioning. Mean fatigue strength was expressed in percentage of initial strength: For 10(4), 10(5), and 10(6) cycles, the results were 66%, 58%, and 52%, respectively, for the amalgam and 62%, 62%, and 53% for the composite group. It is concluded that fatigue-testing of more complex systems is possible, if a suitable testing method is selected. The restorations showed a comparable strength reduction after 10(6) cycles of about 50% of their initial strength. The composite core build-up showed a behavior less predictable than that of the amalgam, which might be attributed to handling parameters.
journal_name
J Dent Resjournal_title
Journal of dental researchauthors
Huysmans MC,van der Varst PG,Schäfer R,Peters MC,Plasschaert AJ,Soltész Udoi
10.1177/00220345920710050301keywords:
subject
Has Abstractpub_date
1992-05-01 00:00:00pages
1145-50issue
5eissn
0022-0345issn
1544-0591journal_volume
71pub_type
临床试验,杂志文章,随机对照试验abstract：:Submandibular glands from young adult and aged male and female rats have been examined and various descriptive parameters obtained. Several sex differences were observed with tissue from young and old animals. Sex differences were found in the gland contents of DNA, protein, and sialic acid and in some protein compone...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345810600051501
更新日期：1981-05-01 00:00:00
abstract：:The differential diagnosis of dental wear lesions affects their clinical management. We hypothesized that surface texture parameters can differentiate simulated erosion, abrasion, and erosion-abrasion lesions on human enamel and dentin. This in vitro study comprised 2 parts (both factorial 4 × 2), with 4 lesion types ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034516629941
更新日期：2016-05-01 00:00:00
abstract：:The cariostatic effect of resin-modified glass ionomer (RMGI) on secondary root caries is well-documented. However, this beneficial effect may be dependent upon the mode of cavity surface treatment. To investigate this relationship, we studied 4 cavity surface treatments prior to the placement of RMGI: no treatment (N...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910308200214
更新日期：2003-02-01 00:00:00
abstract：:Tooth enamel is the most highly mineralized tissue in vertebrates. Enamel crystal formation and elongation should be well controlled to achieve an exceptional hardness and a compact microstructure. Enamel matrix calcification occurs with several matrix proteins, such as amelogenin, enamelin, and ameloblastin. Among th...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034514547272
更新日期：2014-10-01 00:00:00
abstract：:Periodontitis is a chronic inflammatory disease affecting oral tissues. The continuous, high production of cytokines by host cells triggered by periodontopathogens is thought to be responsible for the destruction of tooth-supporting tissues. Macrophages play a critical role in this host inflammatory response to period...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910608500306
更新日期：2006-03-01 00:00:00
abstract：:Pieces of fresh rat incisor enamel were extracted with various buffer solutions and prepared for electron microscopy. I observed partial or complete removal of organic constituents, shrinkage of rods and interrods, separation of stippled material from the enamel, and partial decalcification. The results modify the con...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：
更新日期：1982-12-01 00:00:00
abstract：:These studies defined the normal and hormonally altered development of activity for tyrosine hydroxylase (T-OH), the rate-limiting enzyme in catecholamine biosynthesis (Levitt et al., 1965), and choline acetyltransferase activity (CAT) in the male rat superior cervical ganglion (SCG). Additionally, salivary gland weig...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345870660030901
更新日期：1987-03-01 00:00:00
abstract：:Zirconia-based restorations often fracture from chipping and/or delamination of the porcelain veneers. We hypothesized that veneer chipping/delamination is a result of the propagation of near-contact-induced partial cone cracks on the occlusal surface under mastication. Masticatory loading involves the opposing tooth ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910808701210
更新日期：2008-12-01 00:00:00
abstract：:Defined sets of transcriptional factors can reprogram human somatic cells to induced pluripotent stem (iPS) cells. However, many types of human cells are not easily accessible to minimally invasive procedures. Here we evaluated dental pulp cells (DPCs) as an optimal source of iPS cells, since they are easily obtained ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034510366846
更新日期：2010-08-01 00:00:00
abstract：:This study was undertaken in order to correlate the immune status of persons with various types of immune dysfunctions with the incidence of dental caries. Preliminary data on caries experience and the microbial composition of plaque in these individuals are presented. The findings suggest that persons with immunoglob...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345770560030201
更新日期：1977-03-01 00:00:00
abstract：:The effects of substituting gluconate for extracellular Cl, and of treatment with various ion transport blockers, on cytosol pH (pHi) and secretion by the acetylcholine stimulated rat mandibular gland were studied in vitro. Gluconate replacement increased pHi from 7.12 +/- 0.02 to 7.27 +/- 0.04, caused secretory rate ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345870660022401
更新日期：1987-02-01 00:00:00
abstract：:The cacao bean husk has been shown to possess two types of cariostatic substances, one showing anti-glucosyltransferase (GTF) activity and the other antibacterial activity, and to inhibit experimental dental caries in rats infected with mutans streptococci. In the present study, chromatographic purification revealed h...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345010800111001
更新日期：2001-11-01 00:00:00
abstract：:This study investigated irregularities in hinge movement in 113 subjects. These irregularities were analyzed by computer with an instantaneous three-dimensional "screw axis method." The variation in hinge movement was measured by the dispersion of the hinge axis instant centers. Dispersion of instant centers was great...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345820610010301
更新日期：1982-01-01 00:00:00
abstract：:Macrophage colony-stimulating factor (CSF-1) is a key regulatory cytokine for amelogenesis, and ameloblasts synthesize CSF-1. We hypothesized that PDGF stimulates DNA synthesis and regulates CSF-1 in these cells. We determined the effect of PDGF on CSF-1 expression using MEOE-3M ameloblasts as a model. By RT-PCR, MEOE...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910808700105
更新日期：2008-01-01 00:00:00
abstract：:An analysis of the relationship between creep and microstructural characteristics of several gamma2-containing amalgams showed the grain size of the Ag-Hg phase (gamma1) to be a predominant factor influencing creep. When gamma1 grain size is increased, creep is reduced. ...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345770560121401
更新日期：1977-12-01 00:00:00
abstract：:Cardiovascular disease is a common cause of morbidity and premature mortality. Cardiovascular disease can be prevented when risk factors are identified early. Calcified carotid artery atheromas (CCAAs), detected in panoramic radiographs, and periodontitis have both been associated with increased risk of cardiovascular...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/0022034519885362
更新日期：2020-01-01 00:00:00
abstract：:To determine the 'hard palate representing' area in the primary somatosensory cortex, we recorded somatosensory-evoked magnetic fields from the cortex in ten healthy volunteers, using magnetoencephalography. Following electrical stimulation of 3 sites on the hard palate (the first and third transverse palatine ridges,...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910708600313
更新日期：2007-03-01 00:00:00
abstract：:Masticatory muscle silent periods were compared in normal subjects and in patients with MPD syndrome before and after a variety of psychological, physiological, and pharmacological forms of therapy. All patients initially showed prolonged silent periods in one or more of the muscles. There was a direct relationship be...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345810600030501
更新日期：1981-03-01 00:00:00
abstract：:IL-18 is a pro-inflammatory cytokine that is important in the regulation of T-cells and is elevated in inflammatory disorders such as periodontal disease. Vasoactive intestinal peptide (VIP) modulates immune responses to the periodontal pathogen Porphyromonas gingivalis (Pg). Our objective was to investigate the effec...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910708600915
更新日期：2007-09-01 00:00:00
abstract：:The balance between bone resorption and bone formation is vital for maintenance and regeneration of alveolar bone and supporting structures around teeth and dental implants. Tissue regeneration in the oral cavity is regulated by multiple cell types, signaling mechanisms, and matrix interactions. A goal for periodontal...
journal_title：Journal of dental research
pub_type： 杂志文章,评审
doi：10.1177/0022034515618887
更新日期：2016-03-01 00:00:00
abstract：:Teas varying in fluoride and tannin concentration were evaluated in rats for anticariogenic activity. There was a direct correlation between fluoride in tea and the inhibition of sulcal caries in rats, whereas no relationship was observed between tannin and this type of lesion. Teas also had a significant effect on ca...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345840630051001
更新日期：1984-05-01 00:00:00
abstract：:During amelogenesis in the rat incisor, modulating ruffle-ended (RA) and smooth-ended (SA) ameloblasts are distributed as bands in the enamel organ of the maturation zone. This distribution of the two cell types has been shown to be precisely correlated with a banding of the underlying enamel, as shown by staining and...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345890680020101
更新日期：1989-02-01 00:00:00
abstract：:The effects of oral rinses on enamel fluoride uptake, caries, and plaque pH in rats were investigated by use of (1) an acidic calcium phosphate solution (CPS) saturated with dicalcium phosphate dihydrate (DCPD) and (2) a 1% fluoride solution. Osborne-Mendel rats, 19 days of age, were randomly assigned to one of four m...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345880670061401
更新日期：1988-06-01 00:00:00
abstract：:The biogenetic formation of mineral crystals, one aspect of biomineralization, is a multistep process of apatite formation throughout the growth of dentin tissue. An important step is the transformation of the non-mineralized predentin matrix to mineralizing dentin matrix and its biological control. In this study, the...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345980770081401
更新日期：1998-08-01 00:00:00
abstract：:Enamel fluorosis can occur following either an acute or chronic exposure to fluoride during tooth formation. Fluorosed enamel is characterized by a retention of amelogenins in the early-maturation stage, and by the formation of a more porous enamel with a subsurface hypomineralization. The mechanisms by which fluoride...
journal_title：Journal of dental research
pub_type： 杂志文章,评审
doi：10.1177/00220345920710051701
更新日期：1992-05-01 00:00:00
abstract：:The bactericidal effect of hexylresorcinol was assessed using bacterial aggregates. Increased drug concentration resulted in decreased survival of bacteria when the aggregates were exposed to hexylresorcinol for at least eight hours. This indicates that this drug may be effective against dental plaque only when availa...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345790580111501
更新日期：1979-11-01 00:00:00
abstract：:Dental epithelial progenitor cells differentiate into various cell types during development of tooth germs. To study this mechanism, we produced immortalized dental epithelial progenitor cells derived from the cervical-loop epithelium of a rat lower incisor. The expression patterns of cytokeratin 14, nerve growth fact...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910408300209
更新日期：2004-02-01 00:00:00
abstract：:A conceptual means of obtaining improved bonding between filler particles and the polymeric binders of composites is presented. It involves preparing glass particles that separate into two interconnected vitreous phases when heated to an appropriate temperature, and then etching these to produce a porous surface layer...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345760550050701
更新日期：1976-09-01 00:00:00
abstract：:In vitro wear data were determined for nine experimental composites and compared with two-year clinical data. The in vitro tests included single-pass wear and two-body abrasion. The in vivo data were obtained between 1978 and 1980 for 54 class 2 posterior composite restorations in 25 patients. Correlations between the...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/00220345830620101801
更新日期：1983-10-01 00:00:00
abstract：:Non-steroidal anti-inflammatory drugs (NSAIDs) are used to manage pain and inflammatory disorders. We hypothesized that gingival fibroblasts actively accumulate NSAIDs and enhance their levels in gingival connective tissue. Using fluorescence to monitor NSAID transport, we demonstrated that cultured gingival fibroblas...
journal_title：Journal of dental research
pub_type： 杂志文章
doi：10.1177/154405910608500511
更新日期：2006-05-01 00:00:00
