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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acid etch biopsy specimens of human enamel surfaces treated with a TiF4 solution have shown fluoride uptake to be significantly greater than in untreated surfaces, but less than that obtained with an APF solution of the same fluoride concentration. The TiF4 treated surfaces, however, do show a statistically significant reduction in the acid solubility of the enamel. The presence of acid-resistant coating was shown by SEM.
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PMID:Effects of titanium tetrafluoride on human enamel. 106 52

This SEM study evaluated the micromorphological effect of a 1.23 percent acidulated phosphate fluoridated gel (Oral B)(APF) on the surface of a glass ionomer cement (Ketac-Fil). Glass ionomer (GI) cylinders (area 6.69 mm) were prepared and divided into seven groups of ten specimens each: Group 1, glaze, no polishing; Group 2, glaze, polishing, glaze; Group 3, glaze, no polishing, APF for four minutes; Group 4, glaze, polish, glaze, APF for four minutes; Group 5, no glaze, no polish, APF for four minutes; Group 6, no glaze, polish, APF for four minutes; Group 7, glaze, polish, two coats of glaze, APF for four minutes. The glass ionomer was handled according to manufacturer's instructions, except for groups 5 and 6, where no glaze was used. Polishing was done with medium Sof-Lex discs, using slow-speed and water. The glaze resin (Ketac-Glaze) was painted with a brush over the GI surface and cured with visible light (Demetron) for thirty seconds. In Group 7, the first coat was cured and then the second coat was applied. The APF was applied with a cotton applicator for four minutes, rinsed, and dried. All specimens were then mounted on aluminum stubs, coated, and evaluated under the SEM. The results indicated that the glaze tends to contract or incorporate into the GI matrix in all groups. When APF was used over the GI, the amount of glaze remaining over the surface was diminished, exposing the GI surface. When two coats of the glaze were used, minimal GI surface was exposed after APF treatment.
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PMID:Effect of APF gel on a glass ionomer cement: an SEM study. 143 May 1

Initial lesions in bovine enamel were remineralized in vitro for periods lasting from one hour to two weeks; in some cases, remineralization was interrupted daily for a ten-minute APF application. After two weeks, surface coatings appeared on APF-treated specimens; SEM and TEM observations, including selected area and micro-electron diffraction, indicated both a layered structure within these coatings, and the predominance of calcium fluoride single crystals, ranging from 0.1 to 1.0 micrometer in size. Using double (45 Ca and 32 P) labeled remineralizing solutions, we obtained depth profiles of deposited labeled calcium and phosphate; these indicated that repeated APF applications prevented inward penetration of calcium and phosphate and limited the deposition of these ions to an outer surface region corresponding to the surface coating. These phenomena are explained in terms of the composition and apparent reactivity of the coating.
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PMID:Influence of repeated APF applications on long-term remineralization of initial lesions in bovine enamel. 385 12

A laboratory study was conducted to determine effects of 1.23% APF gel on three composite resins. All composite resins immersed in APF gel lost significantly more weight than did their controls with significantly different weight losses among the APF-treated composites. Surfaces of all resins exposed to APF gel, as viewed in SEM's, exhibited degradation of filler particles.
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PMID:In vitro effect of APF gel on three composite resins. 657 28

The production of tenacious surface coatings on enamel after metal ion mordanting followed by APF has been reported to prevent caries-like lesion initiation in vitro. In this study, similar surface coatings, which may be responsible for the inhibition of lesion progression, were examined using SEM and microprobe analysis. Relatively thick, even surface coatings which were in intimate contact with the enamel surface of caries-like lesions were seen after zirconium and iron (ferric) pre-treatment, but a thinner and unevenly distributed coating was seen after titanium pre-treatment. This latter coating was similar to that seen after APF treatment alone. Fluoride concentrations on the surface and in the subsurface of caries-like lesions were similar for all treatment groups. The surface coatings after zirconium and iron mordanting may be responsible for the greater inhibition of lesion progression than that seen after both titanium pre-treatment and APF treatment alone.
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PMID:Microprobe and SEM analysis of surface coatings on caries-like lesions in enamel after metal ion mordanting and APF application. 658 89

The fluoride (F) uptake from two commercial prophylaxis pastes and a newly formulated prophylaxis paste was compared. The enamel fluoride uptake of 26 extracted sound human molars was measured using an acid etch biopsy method. The F uptakes in ppm (mean +/- SEM) for the control prophy pastes (C), Zircate treatment paste (Z), an APF paste (Nuppro,A), and a new experimental paste (N) were 1145 +/- 65,1245 +/- 72,1857 +/- 296, and 1841 +/- 321, respectively. The enamel biopsy depths in micrometers (mean +/- S.D.) for the control, Zircate APF pastes, and Newpaste were 6.64 +/- 1.75, 7.4 +/- 2.32, 6.55 +/- 2.23 and 7.69 +/- 1.80. The Newpaste appeared to give a significantly higher fluride uptake than Zircate and control pastes, but was very similar to an APF paste.
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PMID:Evaluation of fluoride prophylaxis pastes. 694 Aug 71

This SEM study evaluated the micro morphological effect of a 1.23% acidulated phosphate fluoride gel (Oral-B)(APF) on the surface of VariGlass and Vitrebond light-cured glass ionomer cements with or without Ketac Glaze protective surface glazing. Glass ionomer (GI) cylinders (area 6.69 mm) were prepared and divided into six groups of 10 specimens each: Group 1: VariGlass; Group 2: VariGlass + APF gel for 4 minutes; Group 3: VariGlass + Ketac Glaze; Group 4: VariGlass + Ketac Glaze + APF for 4 minutes; Group 5: Vitrebond; Group 6: Vitrebond + APF gel for 4 minutes; Group 7: Vitrebond + Ketac Glaze; Group 8: Vitrebond + Ketac Glaze + APF for 4 minutes. The cements were handled according to manufactures' instructions, except for the groups using the glaze after light-curing the GI. The Ketac Glaze resin was painted with a brush over the GI surface and cured with visible light (Demetron) for 30 seconds. The fluoride gel was left in contact with the surface for 4 minutes, rinsed and dried. All specimens were then mounted on aluminum stubs, coated and evaluated under the SEM. The results indicated that the APF gel etches both GI surfaces considerably and that the unfilled resin glaze protects the GIs from the erosive effects of the APF gel.
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PMID:Effect of APF gel on light-cured glass ionomer cements: an SEM study. 805 89

The effect of home-use topical fluorides on the surface integrity of two glass ionomers and a composite was studied using SEM. Class V cavities prepared in extracted teeth were restored with two commercial glass ionomers and a composite. Teeth were randomly divided into groups and each group treated for 24 h with one of the following fluoride gels: acidulated phosphate fluoride (pH5), stannous fluoride (pH4.5), sodium fluoride (pH7), and a non-proprietary sodium fluoride (pH5.8). Surface degradation of the restorations was studied using SEM, rated according to specific criteria, and statistically analyzed by the Wilcoxon test (Rank Sums). It was found that the APF and the non-proprietary gel had a significant effect on both Gl matrix and particles and on the composite particles (p < 0.01). The neutral sodium fluoride had no significant effect on the materials (p > 0.01).
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PMID:Effect of home-use fluoride gels on glass ionomer and composite restorations. 829 74

This SEM study evaluated the micromorphological effect of a 1.23% acidulated phosphate fluoride gel (Oral-B) (APF) and a neutral 1.1% sodium fluoride gel (Thera-Flur) (Colgate-Hoyt) on the surface of a light-cured glass ionomer cement (Fuji II LC) with or without a protective surface glazing. Glass ionomer (GI) cylinders (area 6.69 mm) were prepared and divided into six groups of 10 specimens each: Group 1: GI; Group 2: GI + APF gel for 4 minutes; Group 3: GI + glaze; Group 4: GI, glaze, APF for 4 minutes; Group 5: GI, neutral fluoride for 4 minutes; Group 6: GI, glaze, neutral fluoride for 4 minutes. The glass ionomer was handled according to manufacturer's instructions, except for the groups using the glaze after light-curing the GI. The glaze resin (Ketac-Glaze) was painted with a brush over the GI surface and cured with visible light (Demetron) for 30 seconds. The fluoride gels were left in contact with the surface for 4 minutes, rinsed and dried. All specimens were then mounted on aluminum stubs, coated and evaluated under the SEM. The results indicated that the APF gel etches the GI surface considerably and that the glaze protects the GI from the APF gel. The neutral fluoride gel had no significant effect on the GI surface with or without the glaze application.
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PMID:Effect of fluoridated gels on a light-cured glass ionomer cement: an SEM study. 846 45

Intra-oral repair of fractured porcelain is a challenging clinical necessity, because time, economics, as well as possible trauma to teeth, often contra-indicate replacement of the original restoration. The purpose of this study was to evaluate the bond strength of seven different porcelain repair systems used in combination with Cerec Vitablocs Mark II porcelain. The systems were Scotchbond Multi-Purpose (SMP), All-Bond 2 (AB), Optibond (OB), C&B Metabond (CB), Imperva Bond (IB), Silistor (S) and Mirage Bond (MB). When Mirage Bond was used, the porcelain was either etched with 9.6 percent hydrofluoric acid for 2 min (10 specimens = MB1) or with 4 percent APF gel for 2 min (10 specimens = MB2). The shear bond strengths (SBS) of all the products were determined using an Instron. The effects of the pretreatments on the porcelain with different systems were also examined in a SEM. Data were statistically analysed (Wilcoxon Sum of Rank Test). The mean SBS (MPa) of the products were: SMP = 22.6 +/- 6.5; AB = 17.1 +/- 4.1; OB = 17.1 +/- 2.3; CB = 25.8 +/- 4.2; IB = 18.3 +/- 5.2; S = 16.4 +/- 3.7; MB1 = 13.1 +/- 3.9 and MB2 = 6 +/- 2.1. CB and SMP were significantly stronger (p < 0.05) than all other products, with MB2 statistically weaker (p < 0.01) than the other groups. Most specimens showed cohesive fractures in the porcelain, except when MB was used with 4 percent APF gel, where all samples fractured at the adhesive interface. It can be concluded that all seven systems can be used to repair Cerec Porcelain, except possibly MB when used in conjunction with 4 percent APF etchant.
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PMID:Repair of Cerec porcelain with seven different systems. 946 29


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