resin-modified
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Cílem této studie bylo srovnat pevnost vazeb 5-ti adhezivních materiálů ve zkoušce tahem: kompozitních pryskyřic - Brackfix (VOCO, Germany), Light Bond (Reliance Orthodontic Products, Itasca, IL, USA), No-mix (American Orthodontics, USA) a pryskyřicí modifikovaných GIC - Fuji OrthoLC (GC Corporation, Tokyo, Japan) a Fuji Ortho (GC Corporation, Tokyo, Japan). Kovové zámky (Omni Arch, GAC) byly lepeny na vestibulární plochu extrahovaných 100 lidských premolárů (5 skupin po 20). Testovací stroj byl ZWICK Z020. Ačkoli pevnost vazby kompozitních adheziv byla signifikantné vyšší, všechna adheziva vykázala dostatečné vysokou pevnost vazby pro rutinní použití.
The aim of the presented study was to compare bond strength of 5 adhesive materials by means of tensile test: composite resins - Brackfix (VOCO, Germany), Light Bond (Reliance Orthodontic Products, Itasca, IL, USA), Nomix (American Orthodontics, USA), and resin modified GIC - Fuji Ortho LC (GC Corporation, Tokyo, Japan) and Fuji Ortho (GC Corporation, Tokyo, Japan). Metal brackets (Omni Arch, GAC) were bonded to buccal surface of 100 extracted human premolars (5 groups of 20 each). Testing machine was - ZWICK Z020. Though the bond strength of composite resins was significantly better, all the adhesives proved sufficient for clinical practice.
- Klíčová slova
- brackfix, light bond, no-mix, GIC-fuji ortho LC, fuji ortho,
- MeSH
- adheziva chemie MeSH
- lidé MeSH
- ortodontické zámky MeSH
- pevnost v tahu MeSH
- skloionomerní cementy MeSH
- složené pryskyřice MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- srovnávací studie MeSH
Diffusive gradients in thin-films (DGT) is an in situ passive sampling technique to assess labile trace metal concentrations in different environmental matrix. The technique is consisting of a diffusive domain backed up by a resin gel that binds free metals and metal complexes that dissociate in the diffusive domain. This technique requires specific resin for special metals, for example mercury (Hg), since the classic resin (Chelex-100) gel is not applicable for Hg measurement. A simultaneous determination of Hg with other metals by the DGT was not yet reported. Two biomolecule-based resins were prepared by glutaraldehyde immobilisation of cysteine onto 3-amino-functionalised silica and 3-aminopropyl-functionalised silica, respectively. The load of functional groups on modified resins was qualitatively and quantitatively characterised. The modified resins were applied in the DGT technique and the uptake efficiency, elution efficiency, and linear accumulation of analytes of the DGT were tested. This novel DGT technique, using two cysteine-modified resins, can accumulate Hg and other metals in a broad range of pH and ionic strength in solutions. In the Belgian coastal zone (BCZ), the concentrations of Hg and other trace metals sampled by cysteine-modified resin-DGTs were similar as those by the other two DGT assemblies for Hg and other trace metals, respectively. The cysteine-modified silica resin combined the features of Chelex-100 resin and 3-mercaptopropyl silica resin and allowed simultaneous determination of labile Hg and other trace metals. The resin with a higher load of functional groups also showed higher performance in the further application in the DGT technique.
OBJECTIVE: To evaluate the influence of different types of modifications with resin on fatigue resistance and failure behavior of CAD-CAM resin nano ceramic (RNC) restorations for maxillary first premolars. METHODS: Sixty standardized resin composite root dies received CAD-CAM RNC endocrowns (n=30) and crowns (n=30) (Lava Ultimate, 3M Espe). Restorations were divided into six groups: full anatomic endocrowns (group A) and crowns (group D), buccal resin veneered endocrowns (group B) and crowns (group E) and buccal resin veneered endocrowns (group C) and crowns (group F) with a central groove resin filling. A nano-hybrid resin composite was used to veneer the restorations (Filtek Supreme, 3M Espe). All specimens were first submitted to thermo-mechanical cyclic loading (1.7Hz, 49N, 600000 cycles, 1500 thermo-cycles) and then submitted to cyclic isometric stepwise loading (5Hz) until completion of 105000 cycles or failure after 5000 cycles at 200N, followed by 20000 cycles at 400N, 600N, 800N, 1000N and 1200N. In case of fracture, fragments were analyzed using SEM and modes of failure were determined. Results were statistically analyzed by Kaplan-Meier life survival analysis and log rank test (p=0.05). RESULTS: The differences in survival between groups were not statistically significant, except between groups D and F (p=0.039). Endocrowns fractured predominantly with a mesio-distal wedge-opening fracture (82%). Partial cusp fractures were observed above all in crowns (70%). Analysis of the fractured specimens revealed that the origin of the fracture was mainly at the occlusal contact points of the stepwise loading. SIGNIFICANCE: Veneering of CAD-CAM RNC restorations has no influence on their fatigue resistance except when monolithic crowns are modified on their occlusal central groove.
The effect of smear layer-deproteinizing pretreatment using hypochlorous acid (HOCl) on the micro-shear bond strengths (μSBS) of conventional and resin-modified glass-ionomer cements (GIC) to dentin was investigated and compared with demineralizing pretreatment with polyacrylic acid (PAA). Three GICs: Fuji IX GP Extra (restorative conventional GIC), GC Fuji II LC EM (restorative resin-modified GIC), and GC Fuji Luting EX (luting resin-modified GIC), were used. One hundred fifty human molars were divided into groups (n = 10) according to the cements and dentin pretreatments; no pretreatment (control), 10 s PAA pretreatment, and HOCl pretreatment for 5, 15, or 30 s. After 24 h, μSBS was tested and the data were statistically analyzed using a two-way ANOVA, followed by Tukey's post-hoc test. HOCl pretreatment significantly increased μSBS of conventional GIC compared to the control group. For resin-modified restorative GIC, 5 s HOCl deproteinization significantly increased μSBS, while longer application times did not. There was no significant difference between HOCl-pretreated and control groups of resin-modified luting GIC. PAA pretreatment increased the μSBS of all cements significantly. In conclusion, smear layer deproteinization with HOCl can enhance the dentin bonding of conventional GIC. However, the residual radicals may adversely affect the polymerization of resin-modified GICs.
V současnosti jsou na dentálním trhu tři základní typy adhezivních materiálů pro lepení ortodontických zámků - kompozitní pryskyřice, kompomery a pryskyřicí modifikované skloionomerní cementy Cílem tohoto sdělení je popsat hlavní fyzikální a chemické vlastnosti těchto materiálů, jejich techniku zpracování a indikace použití.
Curently there are available three basic types of adhesive materials for bonding of orthodontic brackets - composite resins, compomers and resin modified glass ionomer cements. The aim of the article is to describe principal physical and chemical features of the materials mentioned, the method of their processing and indications for their use.
Ošetření pacientů s radiačním kazem vyžaduje důslednou spolupráci ošetřujícího lékaře a pacienta. Kromě preventivních opatření hraje klíčovou roli správná volba výplňového materiálu. Současné studie doporučují a naše zkušenost potvrzuje antikariogenní působení materiálů permanentně uvolňujících fluoridové ionty, které Christensen dělí do čtyř kategorií: 1. klasické sklopolyalkenoátové cementy, 2. pryskyřicí modifikované sklopolyalkenoátové cementy, 3. sklopolyalkenoátové cementy s vysokou pevností (kondenzovatelné), 4. kompomery.
The treatment of patients with radiation caries requires a thorough collaboration between the physician and the patient. In addition to preventive measures, a key role is played by correct selection of the filling material. Present studies recommend, and our experience confirms, the anti-caries effects of materials which permanently release fluorine ions, divided into four categories by Christensen. 1. classical glass-polyalkenoate cements, 2. resin-modified glass-polyalkenoate cements, 3. glass-polyalkenoate cements of high strength (condensed), 4. copolymers.
- MeSH
- finanční podpora výzkumu jako téma MeSH
- kompomery terapeutické užití MeSH
- lidé MeSH
- radiační účinky MeSH
- skloionomerní cementy terapeutické užití MeSH
- zubní kaz etiologie terapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
