This study compares four different notch shapes made on the anterior margin of the palatal plates of heat-cured acrylic resin test specimens as well as the effect of self-cured acrylic resin repair on the fatigue resistance of dentures. The test specimens had the shape of an upper partial denture (n = 25). The fatigue test applied was a constant-force fatigue test at a force of 150 N. The stress concentrations during loading the replicas of the test specimens were determined in the field of a circular polarized light. The results showed that the fatigue resistance of the test specimens decreased dramatically (P = 0.002) when there was a notch at the anterior margin of the palatal plate in the test specimen. A 90 degree notch decreased the fatigue resistance most effectively. The test specimens repaired with self-cured acrylic resin were also weaker than the original unnotched test specimens. Examination of the replicas in the field of polarized light showed that stresses occurred only very close to the notch. The highest stress concentrations were detected in the test specimen with a 90 degree notch, i.e. the test specimens with the lowest fatigue resistance. The results of this study suggest that the shape of the anterior margin of the palatal plate in the acrylic resin-based partial denture plays an important role in the fatigue resistance of the dentures.
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http://dx.doi.org/10.1111/j.1365-2842.1996.tb01218.x | DOI Listing |
Asian Pac J Cancer Prev
January 2025
Department of Pathology, Phramongkutklao College of Medicine, Thailand.
Objective: To determine the correlation among five different types of tumor regression grading (TRG) systems. Test-retest reliability analyses were conducted at two time points to assess the internal validity and consistency of these five TRG systems.
Methods: A test-retest study was performed in 34 pathologically confirmed rectal adenocarcinoma specimens.
Microbiol Spectr
January 2025
Department of Medicine, Rutgers New Jersey Medical School, Newark, New Jersey, USA.
Tongue swabs represent a potential alternative to sputum as a sample type for detecting pulmonary tuberculosis (TB) with molecular diagnostic tests. The methods used to process tongue swabs for testing in the World Health Organization-recommended Xpert MTB/RIF Ultra (Xpert Ultra) assay vary greatly. Here, we aimed to identify the optimal tongue swab processing for Xpert Ultra testing.
View Article and Find Full Text PDFJ Med Virol
February 2025
Department of Medical Technology, Faculty of Health Sciences, Kyorin University, Tokyo, Japan.
In cervical cancer screening, cytology is used as a triage test to refer high-risk human papillomavirus (HR-HPV)-positive women for colposcopy, but its accuracy is inadequate. The present study aimed to demonstrate that the presence of atypical cells with large vacuoles in the cytoplasm of parabasal cells, referred to as vacuolated parabasal cells (VPCs), which are observed in the Pap smears of HPV-positive women, is associated with specific HPV genotypes. Among 2175 patients, 310 with a single HR-HPV infection and cytological diagnosis of high-grade squamous intraepithelial lesions (HSIL) or atypical squamous cells not excluding HSIL (ASC-H) were included, of which 86 were infected with HPV16.
View Article and Find Full Text PDFJ Dent Sci
January 2025
School of Dentistry and Institute of Oral Medicine, National Cheng Kung University, Tainan, Taiwan.
Background/purpose: The efficacy of riboflavin-ultraviolet-A (RF-UVA) treatment in crosslinking collagen and improving dentin bonding has been proven. However, biodegradation of the hybrid layer may compromise the bonding. The purpose of this study was to evaluate different RF-UVA treatments regarding their ability to preserve dentin bonding from enzymatic digestion.
View Article and Find Full Text PDFJ Dent Sci
January 2025
Department of Conservative Dentistry, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea.
Background/purpose: This study assessed the ability of experimental materials consisting of dicalcium silicate (DCS) and tricalcium silicate (TCS) with nanosized particles to form intratubular crystals under phosphate-buffered saline (PBS) and the effect on dentin permeability reduction.
Materials And Methods: By isolating the cervical part of the extracted premolars, 195 specimens were obtained. Two experimental materials (DCS/TCS and TCS) were applied to the dentin surface by brushing and stored in PBS (n = 65).
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