Statement of problem. Direct bonding of orthodontic brackets to porcelain surfaces has been plagued by failure. Purpose. The purpose of this study was to compare the bond strengths of several different bonding systems...
Statement of problem. Direct bonding of orthodontic brackets to porcelain surfaces has been plagued by failure. Purpose. The purpose of this study was to compare the bond strengths of several different bonding systems when bonding orthodontic brackets to porcelain-fused-to-metal surfaces. Material and methods. Fifty natural glazed feldspathic porcelain-fused-to-noble metal disks 6 mm in diameter and 3 mm in height (1 mm metal and 2 mm porcelain) were fabricated and divided into 5 groups of 10. A different bonding system (GC America Fuji LC, American Ortho Spectrum, 3M Transbond, TP Orthodontics Python, and Kerr Herculite) was assigned to each group, and 50 identical orthodontic brackets were bonded (with the above mentioned systems) to each disk according to each manufacturer's instructions. Each system except TP Orthodontics Python conditioned with phosphoric acid (35% to 37.5%) and all systems were primed with silane before bonding. The specimens were subjected to gradual shear forces tip to 123 N in a universal testing machine (Instron Corp, Canton, Mass.) until fracture. The shear bond strength of the bonding systems between the porcelain surface and the bracket was measured in megapascals (MPa). Failures were observed via a Zeiss optical microscope (10x);Tukey's HSD Test and analysis of variance were used to determine significance between the bonding systems at P<.05 level of significance. Results. Failure of all of specimens was adhesive between the porcelain surface and the bonding agents. On the basis of a current literature review, bonding systems were categorized as clinically acceptable if they bad a shear bond strength of 6 to 8 MPa. The 3M Transbond Bonding System, American Orthodontics Spectrum Bonding System, and GC America Fuji Ortho LC Bonding System performed within this clinically acceptable range (6 to 8 MPa), whereas Kerr Herculite Bonding System and TP Orthodontics Python Bonding System did not (2 to 4 MPa). The bond strengths of GC America Fuj
This case report demonstrates Mineral Trioxide Aggregate obturation of the root canal system of a retained primary mandibular second molar where no succedaneous permanent tooth was present. The technique seemed to pro...
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This case report demonstrates Mineral Trioxide Aggregate obturation of the root canal system of a retained primary mandibular second molar where no succedaneous permanent tooth was present. The technique seemed to provide a biocompatible seal of the root canal system in this case. It is not recommended for obturation of primary teeth that are expected to exfoliate since it is anticipated that Mineral Trioxide Aggregate would be absorbed slowly, if at all.
作者：
Goodell, GGGallagher, FJNicoll, BKUSN
Dent Ctr SE Air Stn Jacksonville AEGD Postgrad Program Jacksonville FL 32212 USA USN
Sch Postgrad Dent Dept Periodont Bethesda MD 20084 USA
Objective. The purpose of this study was to compare a device that controls flow rate during injection through use of a foot pedal with a conventional atraumatic syringe injection technique. We determined the change fr...
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Objective. The purpose of this study was to compare a device that controls flow rate during injection through use of a foot pedal with a conventional atraumatic syringe injection technique. We determined the change from preinjection to postinjection anxiety, the pain perception, procedure tolerance, and anxiety about future injections. Study design. Dental injection anxiety questionnaires were completed by 80 endodontic patients immediately before and after administration of local anesthetic with the 2 experimental methods. Patients also completed visual analog scales to rate their pain perception during injection, their rating of the overall experience, and their anticipated anxiety about a future dental injection. Results. Patients experienced significantly lower overall postinjection anxiety and pain of injection and had significantly more positive overall experience ratings with the conventional technique than with the controlled-rate procedure. Conclusions. A conventional atraumatic syringe injection technique was superior to a controlled injection pressure system in pain perception and procedure tolerance and in reducing postinjection dental anxiety.
Conveying news of cancer is stressful for the doctor, as receiving such news is for the patient. A patient may not perceive the news in the same way that the doctor does. Regular incorporation of the suggestions made ...
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Conveying news of cancer is stressful for the doctor, as receiving such news is for the patient. A patient may not perceive the news in the same way that the doctor does. Regular incorporation of the suggestions made in this article will advance the doctor's confidence, communication skills, and relationships with patients.
Directors of Nursing (DONs) from 196 of 206 Nebraska long-term-care (LTC) facilities were sent a pre-tested questionnaire. The aim was to assess available on-site dental services, existing oral health education and pr...
Directors of Nursing (DONs) from 196 of 206 Nebraska long-term-care (LTC) facilities were sent a pre-tested questionnaire. The aim was to assess available on-site dental services, existing oral health education and prevention programs as well as future needs/preferences, and the influence of 10 factors in assessing and maintaining residents' oral health. Of the 196 DONs contacted, 126 (64%) participated. Only 36% of DON responders reported having on-site dental services. DONs indicated a preference for nursing staff (NS) oral health in-service training over other educational and/or programmatic proposals. When asked to select the five most influential factors in assessing and maintaining residents' oral health in their respective facilities, DONs selected resident factors (mean, 2.8) more often than NS factors (mean, 2.2). DONs most often identified residents' (R′) ability to perform oral hygiene (n = 99), R′ cooperation with OH assistance (n = 98), R′ interest in their oral health (n = 83), NS interest in R′ dental health (n = 70), and NS time constraints (n = 69).
A clinical study was performed to determine if placement of an amalgam retroseal resulted in elevated blood mercury levels, Ten subjects had blood drawn 7 days before and immediately before placement of an amalgam ret...
A clinical study was performed to determine if placement of an amalgam retroseal resulted in elevated blood mercury levels, Ten subjects had blood drawn 7 days before and immediately before placement of an amalgam retroseal, Postoperative blood draws occurred at 7 and 30 days. Blood samples were analyzed for mercury content by Cold-Vapor Atomic Absorption Spectrophotometry. No statistically significant increase in blood mercury levels was detected at 7 and 30 days after placement of an amalgam retroseal as compared with preoperative levels (p = 0.97). Findings support the hypothesis that placement of an amalgam retroseal does not result in significant elevations of blood mercury levels.
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