Objectives: To determine the minimum exposure times consistent with optimized surface microhardness numbers (VHN) for the top and bottom surfaces, respectively, of a resin composite (1.5-mm depth) cured using a quartz-halogen activation lamp. Additionally, to determine the conditions appropriate to achieve optimized bottom/top hardness ratios.
Method And Materials: Disk specimens of a commercial resin composite restorative (Spectrum TPH) were exposed to a quartz-halogen lamp, and VHNs were measured for the top and bottom surfaces at elapsed times of 1 hour and 24 hours.
Results: Data were dependent on exposure time, time elapsed after exposure, and the surface involved. Exposure time featured limiting values in excess of which no significant increase in microhardness took place. All microhardness data increased significantly over an elapsed time interval between 1 hour and 24 hours postexposure. Microhardness ratios (bottom/top) were dependent on exposure time only and were not influenced by time elapsed after exposure.
Conclusion: Minimum exposure time may be considered as the greater of the times to achieve optimized top hardness and optimized hardness ratio, respectively.
Download full-text PDF |
Source |
---|
Neurogastroenterol Motil
January 2025
Division of Gastroenterology, Rabin Medical Center, Beilinson Campus, Petah Tikva, Israel.
Background: Proton pump inhibitors (PPI) for gastroesophageal reflux disease (GERD) are associated with a high failure rate. Our uncontrolled feasibility study aimed determining the effect of a transcutaneous electrical stimulation system (TESS) on GERD symptoms and acid exposure time (AET).
Methods: Recruited patients with heartburn and regurgitation.
Rev Med Suisse
January 2025
Unité des dépendances, Service de médecine de premier recours, Hôpitaux universitaires de Genève, 1211 Genève 14.
The use of psychoactive substances affects more men than women, with a prevalence that is 1.3 to 2 times higher, except for the use of sedatives. Men are also more affected by accidents, injuries, and acts of violence.
View Article and Find Full Text PDFSurg Pract Sci
September 2023
Department of Surgery, Bassett Medical Center, Cooperstown, NY, USA.
Background: Rural hospitals cover 20% of the United States (US) population with only 10% of physician coverage. A mismatch exists in pediatric trauma resources as there is overwhelming trauma support concentrated in urban trauma centers. Well-established guidelines for evaluating pediatric trauma patients in resource-limited environments are currently not available.
View Article and Find Full Text PDFFront Public Health
January 2025
Department of Epidemiology, School of Public Health, Cheeloo College of Medicine, Shandong University, Jinan, China.
Introduction: Facing Mount Tai in the south and the Yellow River in the north, Zibo District is an important petrochemical base in China. The effect of air pollution on cardiovascular diseases (CVDs) in Zibo was unclear.
Methods: Daily outpatient visits of common CVDs including coronary heart disease (CHD), stroke, and arrhythmia were obtained from 2019 to 2022 in Zibo.
Contemp Clin Dent
December 2024
Department of Periodontology, Faculty of Dentistry, Mohamed V University, Rabat, Morocco.
Critical alveolar ridge defects can result from several causes. Ridge expansion is a technique that aims to increase the width of the bone crest. A male patient presented an edentulous segment which leads to be careful concerning the adjacent teeth.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!