http://www.dentalnews.com.br/downloads/artigos-cientificos/pinos-RTD/Ma…
A review of adhesion science.
Sally J. Marshalla,c,∗, Stephen C. Bayned, Robert Baierb, Antoni P. Tomsiac,a, Grayson W. Marshalla,c
a University of California, San Francisco, United States b University at Buffalo, United States c Lawrence Berkeley National Laboratory, United States d University of Michigan, United States
Micro-mechanical bonding is the basis of most of contemporary adhesive dentistry. It depends on microsized relief of enamel and dentin surfaces to allowadhesive penetration that interlocks it into surface spaces. The surface relief is created by acid etching. The interlocking occurs at two levels. The first involves the formation of microtags of resin around enamel prisms or within dentinal tubules. The second involves amuch finer penetration of adhesive nanotags among enamel crystals or into the dentin collagen spaces. Nanotags seem to bemuch more important to overall retention and can be imagined as a nano-interdigitation mechanism. These adhesive bonds involve the formation of an interphase. Determination of parameters such as permeability coefficient helps to predict the contributions of diffusion bonding [13]. Another interesting result of interphase adhesion is the phenomenon of stringing. During debonding, strings of adhesive are stretched across the original interface, bridging the gap, and preventing complete crack formation.* This discourages the propagation of a crack at the interface. This phenomenon is common with general-purpose adhesives or glues. Nano-interdigitation also occurs when adhesive monomers diffuse into existing polymer phases, polymerize, and become molecularly intertwined with existing molecules. While there are no new chemical bonds formed between the old and new polymer molecules, breaking of one or the other polymer chains is generally required to make the interface fail. This is a mechanism that commonly occurs with methyl methacrylate monomer in acrylic dough systems used for denture bases and teeth or with acrylic bone cements. A related event occurs when atoms or molecules diffuse across an interface, rearrange the bulk material, and eliminate the original boundaries.With metal and ceramic systems, this type of diffusion requires heating to promote atomic movements [1]. A good example is sintering of ceramic or metal powders.
http://www.pha.jhu.edu/~mr/research/adhesion.htm
http://onlinelibrary.wiley.com/doi/10.1002/jbm.10364/abstract?deniedAcc…
The morphologic results in corroboration with the spectroscopic data suggest that as a result of adhesive phase separation the hybrid layer is not an impervious 3-dimensional collagen/polymer network but a porous web characterized by hydrophobic BisGMA-rich particles distributed in a hydrophilic HEMA-rich matrix.
http://www.ncbi.nlm.nih.gov/pubmed/18621460
Abstract
OBJECTIVES:
Small and hydrophilic monomers as HEMA and TEGDMA can easily penetrate human tissues. For biocompatibility issues it is therefore better to avoid such monomers in dental adhesive formulations. The purpose of this study was (1) to determine the micro-tensile bond strength (muTBS) to enamel/dentin of a HEMA/TEGDMA-free three-step etch&rinse adhesive (cmf Adhesive System, Saremco), and (2) to characterize it's interfacial interaction with enamel/dentin using transmission electron microscopy (TEM).
http://ejo.oxfordjournals.org/content/32/6/688.full
Biocompatibility of dental materials is usually neglected in dental practice. Most practitioners purchase materials that are commercially available without any concerns about their biocompatibility. Today, while a number of orthodontic adhesives are used by clinicians, most relevant studies concentrate on their physical properties such as shear bond strength with less emphasis on biological compatibility.
http://www.ncbi.nlm.nih.gov/pubmed/22192249
Abstract
OBJECTIVES:
Methods used to measure and predict clinical biological responses to dental materials remain controversial, confusing, and to some extent, unsuccessful. The current paper reviews significant issues surrounding how we assess the biological safety of materials, with a historical summary and critical look at the biocompatibility literature. The review frames these issues from a U.S. perspective to some degree, but emphasizes their global nature and universal importance.
SIGNIFICANCE:
Today we ask materials to play increasingly sophisticated structural and therapeutic roles in patient treatment. To accommodate these roles, strategies to assess, predict, and monitor material safety need to evolve. This evolution will be driven not only by researchers and manufacturers, but also by patients and practitioners, who want to use novel materials in new ways to treat oral disease.
http://smooz.4your.net/masterson/files/Mechanisms.pdf
a b s t r a c t
The manner in which a mutually acceptable co-existence of biomaterials and tissues is developed and sustained has been the focus of attention in biomaterials science for many years, and forms the foundation of the subject of biocompatibility. There are many ways in which materials and tissues can be brought into contact such that this co-existence may be compromised, and the search for biomaterials that are able to provide for the best performance in devices has been based upon the understanding of all the interactions within biocompatibility phenomena. Our understanding of the mechanisms of biocompatibility has been restricted whilst the focus of attention has been long-term implantable devices. In this paper, over 50 years of experience with such devices is analysed and it is shown that, in the vast majority of circumstances, the sole requirement for biocompatibility in a medical device intended for long-term contact with the tissues of the human body is that the material shall do no harm to those tissues, achieved through chemical and biological inertness. Rarely has an attempt to introduce biological activity into a biomaterial been clinically successful in these applications. This essay then turns its attention to the use of biomaterials in tissue engineering, sophisticated cell, drug and gene delivery systems and applications in biotechnology, and shows that here the need for specific and direct interactions between biomaterials and tissue components has become necessary, and with this a new paradigm for biocompatibility has emerged. It is believed that once the need for this change is recognised, so our understanding of the mechanisms of biocompatibility will markedly improve.
Cavex unibond UniBond Sealer is een gevulde,
fluoride-ionen afgevende röntgenopake sealer.
http://www.cavex.nl/en/products/productcategory/23/sub-26/product-62
http://www.tandarts.nl/phpBB/viewtopic.php?f=16&t=18596
:smt015
A review of adhesion science.
Sally J. Marshalla,c,∗, Stephen C. Bayned, Robert Baierb, Antoni P. Tomsiac,a, Grayson W. Marshalla,c
a University of California, San Francisco, United States b University at Buffalo, United States c Lawrence Berkeley National Laboratory, United States d University of Michigan, United States
Micro-mechanical bonding is the basis of most of contemporary adhesive dentistry. It depends on microsized relief of enamel and dentin surfaces to allowadhesive penetration that interlocks it into surface spaces. The surface relief is created by acid etching. The interlocking occurs at two levels. The first involves the formation of microtags of resin around enamel prisms or within dentinal tubules. The second involves amuch finer penetration of adhesive nanotags among enamel crystals or into the dentin collagen spaces. Nanotags seem to bemuch more important to overall retention and can be imagined as a nano-interdigitation mechanism. These adhesive bonds involve the formation of an interphase. Determination of parameters such as permeability coefficient helps to predict the contributions of diffusion bonding [13]. Another interesting result of interphase adhesion is the phenomenon of stringing. During debonding, strings of adhesive are stretched across the original interface, bridging the gap, and preventing complete crack formation.* This discourages the propagation of a crack at the interface. This phenomenon is common with general-purpose adhesives or glues. Nano-interdigitation also occurs when adhesive monomers diffuse into existing polymer phases, polymerize, and become molecularly intertwined with existing molecules. While there are no new chemical bonds formed between the old and new polymer molecules, breaking of one or the other polymer chains is generally required to make the interface fail. This is a mechanism that commonly occurs with methyl methacrylate monomer in acrylic dough systems used for denture bases and teeth or with acrylic bone cements. A related event occurs when atoms or molecules diffuse across an interface, rearrange the bulk material, and eliminate the original boundaries.With metal and ceramic systems, this type of diffusion requires heating to promote atomic movements [1]. A good example is sintering of ceramic or metal powders.
http://www.pha.jhu.edu/~mr/research/adhesion.htm
http://onlinelibrary.wiley.com/doi/10.1002/jbm.10364/abstract?deniedAcc…
The morphologic results in corroboration with the spectroscopic data suggest that as a result of adhesive phase separation the hybrid layer is not an impervious 3-dimensional collagen/polymer network but a porous web characterized by hydrophobic BisGMA-rich particles distributed in a hydrophilic HEMA-rich matrix.
http://www.ncbi.nlm.nih.gov/pubmed/18621460
Abstract
OBJECTIVES:
Small and hydrophilic monomers as HEMA and TEGDMA can easily penetrate human tissues. For biocompatibility issues it is therefore better to avoid such monomers in dental adhesive formulations. The purpose of this study was (1) to determine the micro-tensile bond strength (muTBS) to enamel/dentin of a HEMA/TEGDMA-free three-step etch&rinse adhesive (cmf Adhesive System, Saremco), and (2) to characterize it's interfacial interaction with enamel/dentin using transmission electron microscopy (TEM).
http://ejo.oxfordjournals.org/content/32/6/688.full
Biocompatibility of dental materials is usually neglected in dental practice. Most practitioners purchase materials that are commercially available without any concerns about their biocompatibility. Today, while a number of orthodontic adhesives are used by clinicians, most relevant studies concentrate on their physical properties such as shear bond strength with less emphasis on biological compatibility.
http://www.ncbi.nlm.nih.gov/pubmed/22192249
Abstract
OBJECTIVES:
Methods used to measure and predict clinical biological responses to dental materials remain controversial, confusing, and to some extent, unsuccessful. The current paper reviews significant issues surrounding how we assess the biological safety of materials, with a historical summary and critical look at the biocompatibility literature. The review frames these issues from a U.S. perspective to some degree, but emphasizes their global nature and universal importance.
SIGNIFICANCE:
Today we ask materials to play increasingly sophisticated structural and therapeutic roles in patient treatment. To accommodate these roles, strategies to assess, predict, and monitor material safety need to evolve. This evolution will be driven not only by researchers and manufacturers, but also by patients and practitioners, who want to use novel materials in new ways to treat oral disease.
http://smooz.4your.net/masterson/files/Mechanisms.pdf
a b s t r a c t
The manner in which a mutually acceptable co-existence of biomaterials and tissues is developed and sustained has been the focus of attention in biomaterials science for many years, and forms the foundation of the subject of biocompatibility. There are many ways in which materials and tissues can be brought into contact such that this co-existence may be compromised, and the search for biomaterials that are able to provide for the best performance in devices has been based upon the understanding of all the interactions within biocompatibility phenomena. Our understanding of the mechanisms of biocompatibility has been restricted whilst the focus of attention has been long-term implantable devices. In this paper, over 50 years of experience with such devices is analysed and it is shown that, in the vast majority of circumstances, the sole requirement for biocompatibility in a medical device intended for long-term contact with the tissues of the human body is that the material shall do no harm to those tissues, achieved through chemical and biological inertness. Rarely has an attempt to introduce biological activity into a biomaterial been clinically successful in these applications. This essay then turns its attention to the use of biomaterials in tissue engineering, sophisticated cell, drug and gene delivery systems and applications in biotechnology, and shows that here the need for specific and direct interactions between biomaterials and tissue components has become necessary, and with this a new paradigm for biocompatibility has emerged. It is believed that once the need for this change is recognised, so our understanding of the mechanisms of biocompatibility will markedly improve.
Cavex unibond UniBond Sealer is een gevulde,
fluoride-ionen afgevende röntgenopake sealer.
http://www.cavex.nl/en/products/productcategory/23/sub-26/product-62
http://www.tandarts.nl/phpBB/viewtopic.php?f=16&t=18596
:smt015
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Mijn eerste topic is in mei geschreven. De brief is van juni....en nee, hoor, ik heb hem niet zelf getypt.
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:-?
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Everybody just follow me
Coz we need a little controversy
It feels so empty without me
Ja lies, je hebt gelijk,en de problemen zitten bij you en cavex.kururay. Settle that and get over that. We kunnen je niet helpen, wij zijn te ff- ing dumb.
Slim mecanico, i m back
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Alleen de link naar een coole sneakersite ontbrak nog.
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Letterlijk niet zwart genoeg...
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De tandarts schrijft in de brief dat hij het met een kwastje vanuit een dappendish heeft aangebracht. Dat heeft hij niet. Het werd met een spuit aangebracht. Maarja, tandartsen liegen niet....Dat doen alleen clienten die gedupeerd zijn..... :-?
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Jij stelt allerlei zaken die je krampachtig met allerlei (meestal niet eens ter zake doende) onderzoeken kracht tracht bij te zetten. Iedereen die iets van materiaalkunde en chemie begrijpt zal inzien dat dit niet kan.. allerlei andere oorzaken die door deze en gene worden aangehaald worden of genegeerd of door jou, hoe plausibel ze ook zijn, terzijde gelegd. Dan ga je roepen dat de tandarts liegt, alleen zijn beschrijving van procedure klopt, en de manier waarvan jij beweert dat het gedaan zou zijn is en erg onlogisch en daarnaast erg onhandig... en daarmee is het ongeloofwaardig dat he tzo gebeurt zou zijn, de rest van het verhaal terzijde. En nu beweer ik niet dat jij liegt, het moet bij jou blijkbaar altijd in zwart-wit, maar het leven is niet zwart wit. Ik stel alleen dat wat jij ervaren hebt , zoals jij het ervaren hebt, en de conclusies die jij trekt die nergens mee echt onderbouwd worden, gewoonweg op zijn minst onlogisch zijn en de plank mis slaan. Waarmee ik niet stel dat je liegt, alleen dat je wellicht eindelijk eens een ander pad moet bewandelen, want hiermee en zo ga je er niet komen....
en al zou het kloppen , wat dan? een kleine minderheid van de patienten is allergisch voor composiet, is een feit. verbieden dan maar? geeft gigantische problemen, wat dan te gebruiken voor vulmateriaal? terug in de tijd en allemaal gouden inlays met zinkfosfaatcement vastgezet, wie kan en wil dat betalen? er is altijd bij elk materiaal een minderheid met problemen...niet alleen bij de tandarts, geldt voor elke medische ingreep. en dat aantal moet zo klein mogelijk, maar het kan nooit voorkomen worden dat het in 100% goed gaat/is....
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Daar heb je ook helemaal gelijk in. Maar geloof me dat men bezig is om deze biomaterialen veiliger te maken. ( zal niet voor niets zijn)Dat gaat alleen niet zo snel. Er zijn inmiddels genoeg onderzoeken aan de gang wat betreft reactie/interactie materiaal/ zacht weefsel. Die mechaniek is nog steeds niet geheel duidelijk. En verspreiding van kennis/wetenschap gaat, jammer genoeg, ook heel traag. En gezien men niets van "ervaringsdeskundigen" aan wil nemen, duurt dat waarschijnlijk nog langer.....
Er is trouwens wel een groot verschil tussen een vergiftiging (door onzorgvuldigheid) en een allergie. Maar zolang men het probleem maar blijft ontkennen/negeren, dan is er geen probleem.
Zo simpel werkt dat....en dan ben je snel uitgewandeld.
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Nah sorry hoor. Kon het niet vinden. Zag wel dat je het in je allereerste bericht ook al niet zinvol vond om de rare gebeurtenis uit te leggen.
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Die materiaaleigenschappen veranderen echt niet als dit goedje op de orale en inwendige slijmvliezen terecht komt, hoor.
Wel grappig dat je je woorden nergens mee onderbouwt....Of moet ik daar maar gewoon vertrouwen in hebben omdat je tandarts bent? Materiaalkunde en tandheelkunde zijn twee verschillende dingen. Je zou de info en microscopische foto's op mijn blog eens moeten bekijken. Misschien dat je het dan wel in wil zien.
Ik kom hier overigens niet voor hulp of advies. Ik probeer de professionals alleen iets duidelijk te maken maar dat blijkt een onmogelijke taak.... :-?
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Het is daarom erg frustrerend hoe men reageert, zeker gezien het feit er wereldwijd tienduizenden mensen met dezelfde klachten rondlopen en allemaal voor gek worden verklaart.
Ik hoop dat iemand ooit toch nog eens wat diepere intresse toont.
Bedankt tot zover. Ik zal jullie met rust laten.
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En gelet op vorige reacties, het is gern desinteresse, maar de onderzoeken die je erbij haaltzijn niet goed opgezet, onderbouwd e n daardoor niet te gebruikenom ietsonveiligte verklaren.
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Bonding word nooooooit met spuitjes aangebracht maar altijd met microkwastjes....... :smt013
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Fout in verband .. Vriendelijk controleren opnieuw.