ABSTRACT
OBJECTIVES: This study was conducted to examine the assessment of abrasion of two different materials after neutron activation. METHODS: A fissure sealant material (Fissurit F/VOCO with a compressive strength of 235 MPa) and a glass ionomer cement (Aqua Ionofil/VOCO with a compressive strength of 170 MPa) were activated by irradiation with neutrons. Subsequent measurements of the full-energy-peak (FEP) (1368.55 keV of 24Na) were made of the sample materials before and after abrasion via exposure to the air-powder polishing to accurately describe substance loss. RESULTS: Abrasion varied more than three-fold between the two materials. SIGNIFICANCE: Neutron activation and radiotracer measurement allows the quantification of abrasion effects in different materials. In comparison with other current methods its use may allow a superior measurement accuracy and precision in determining the abraded mass.
Subject(s)
Air Abrasion, Dental/methods , Dental Polishing/methods , Gamma Rays , Glass Ionomer Cements/chemistry , Neutron Activation Analysis , Pit and Fissure Sealants/chemistryABSTRACT
PURPOSE: To evaluate binocular function after bilateral implantation of a refractive multifocal intraocular lens (IOL). METHODS: Contrast sensitivity, glare, depth discrimination, and distance and near visual acuity were examined in 21 patients with a multifocal IOL and 15 patients with a monofocal IOL. RESULTS: There was no significant difference in binocular distance visual acuity between the 2 groups. In near visual acuity with distance correction, the multifocal group had a significant advantage in monocular and binocular vision (P < .05). High contrast with Regan contrast letter acuity charts did not differ significantly between the groups. However, at a contrast of 11%, sensitivity was significantly lower monocularly in the multifocal group. Contrast sensitivity in this group was not significantly lower binocularly. The brightness acuity tester revealed no between-group difference in glare. With the Titmus stereotest, depth discrimination was significantly better with the multifocal IOL with distance correction. CONCLUSION: Bilateral implantation of a refractive multifocal IOL provided good binocular function and alleviated the well-known disadvantage of reduced contrast sensitivity at low contrast levels.
Subject(s)
Lens Implantation, Intraocular , Lenses, Intraocular , Vision, Binocular/physiology , Astigmatism/etiology , Astigmatism/physiopathology , Astigmatism/therapy , Contrast Sensitivity/physiology , Depth Perception/physiology , Follow-Up Studies , Glare , Humans , Middle Aged , Myopia/etiology , Myopia/physiopathology , Myopia/therapy , Refraction, Ocular/physiology , Retrospective Studies , Visual Acuity/physiologySubject(s)
Child Rearing , Pregnancy in Adolescence , Adolescent , Career Choice , Community Health Services , Female , Humans , Pregnancy , Prenatal Care , WisconsinABSTRACT
In ten years a total of 1207 operations for gastroduodenal ulcer were performed, using a standardizing treatment scheme. The number of operations has markedly decreased since 1978, probably due to the introduction of H2-receptor blockers in the treatment of peptic ulcers. The results of operations suggest elective surgical treatment for ulcer patients at risk of complications. This is the only way of decreasing the adverse effect of emergency operations on the total surgical mortality of ulcer patients.
