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Surface pretreatments for medical application of adhesion.

Erli HJ, Marx R, Paar O, Niethard FU, Weber M, Wirtz DC - Biomed Eng Online (2003)

Bottom Line: Specific pretreatment can significantly increase bond strengths, particularly after long term immersion in water under conditions similar to those in the human body.The bond strength between bone and plastic for example can be increased by a factor approaching 50 (pealing work increasing from 30 N/m to 1500 N/m).This review article summarizes the multi-disciplined subject of adhesion and adhesives, considering the technology involved in the formation and mechanical performance of adhesives joints inside the human body.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Prosthetic Dentistry, Section of Dental Materials, University Hospital of the University of Technology, Aachen, Germany. herli@ukaachen.de

ABSTRACT
Medical implants and prostheses (artificial hips, tendono- and ligament plasties) usually are multi-component systems that may be machined from one of three material classes: metals, plastics and ceramics. Typically, the body-sided bonding element is bone. The purpose of this contribution is to describe developments carried out to optimize the techniques, connecting prosthesis to bone, to be joined by an adhesive bone cement at their interface. Although bonding of organic polymers to inorganic or organic surfaces and to bone has a long history, there remains a serious obstacle in realizing long-term high-bonding strengths in the in vivo body environment of ever present high humidity. Therefore, different pretreatments, individually adapted to the actual combination of materials, are needed to assure long term adhesive strength and stability against hydrolysis. This pretreatment for metal alloys may be silica layering; for PE-plastics, a specific plasma activation; and for bone, amphiphilic layering systems such that the hydrophilic properties of bone become better adapted to the hydrophobic properties of the bone cement. Amphiphilic layering systems are related to those developed in dentistry for dentine bonding. Specific pretreatment can significantly increase bond strengths, particularly after long term immersion in water under conditions similar to those in the human body. The bond strength between bone and plastic for example can be increased by a factor approaching 50 (pealing work increasing from 30 N/m to 1500 N/m). This review article summarizes the multi-disciplined subject of adhesion and adhesives, considering the technology involved in the formation and mechanical performance of adhesives joints inside the human body.

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Related in: MedlinePlus

SEM picture of a demineralized (below) vs. untreated (above) bone surface. The micromechanical retention between resin and compact bone surface may be basically due to resin infiltration into the bone surface demineralized by acid etching to a depth of a few micrometers ("hybrid layer"). The investigations were done on bone from freshly slaughtered sheep.
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Figure 10: SEM picture of a demineralized (below) vs. untreated (above) bone surface. The micromechanical retention between resin and compact bone surface may be basically due to resin infiltration into the bone surface demineralized by acid etching to a depth of a few micrometers ("hybrid layer"). The investigations were done on bone from freshly slaughtered sheep.

Mentions: Basically, the micromechanical retention between resin and compact bone surface is due to resin infiltration into the bone surface demineralized by acid etching to a depth of a few micrometers, thus exposing the collagen fiber network without damaging it (Fig. 10). The degree of retention depends upon the amount of uptake of liquid monomers into the interfibrillar spaces that were previously occupied by apatite mineral crystallites. It is thought that the durability of the resin-to bone bond depends upon how thoroughly the resin infiltrates these spaces, whether all of the exposed collagen fibrils are enveloped by resin, and how well the resin is polymerized. During the etching step, the debris layer described above is likewise removed. Both can be done by weak acids such as citric, maleic, oxalic, or phosphoric acid. EDTA-Fe-Na (ethylene diamine tetra acetic) can be used as an additive since it is suitable for the prevention of the denaturation of the collagen during and after demineralization. In preventing denaturation the ferric ion is especially important. As a further additive glutaric aldehyde can be helpful with protein fixation of collagen fibers.


Surface pretreatments for medical application of adhesion.

Erli HJ, Marx R, Paar O, Niethard FU, Weber M, Wirtz DC - Biomed Eng Online (2003)

SEM picture of a demineralized (below) vs. untreated (above) bone surface. The micromechanical retention between resin and compact bone surface may be basically due to resin infiltration into the bone surface demineralized by acid etching to a depth of a few micrometers ("hybrid layer"). The investigations were done on bone from freshly slaughtered sheep.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC222922&req=5

Figure 10: SEM picture of a demineralized (below) vs. untreated (above) bone surface. The micromechanical retention between resin and compact bone surface may be basically due to resin infiltration into the bone surface demineralized by acid etching to a depth of a few micrometers ("hybrid layer"). The investigations were done on bone from freshly slaughtered sheep.
Mentions: Basically, the micromechanical retention between resin and compact bone surface is due to resin infiltration into the bone surface demineralized by acid etching to a depth of a few micrometers, thus exposing the collagen fiber network without damaging it (Fig. 10). The degree of retention depends upon the amount of uptake of liquid monomers into the interfibrillar spaces that were previously occupied by apatite mineral crystallites. It is thought that the durability of the resin-to bone bond depends upon how thoroughly the resin infiltrates these spaces, whether all of the exposed collagen fibrils are enveloped by resin, and how well the resin is polymerized. During the etching step, the debris layer described above is likewise removed. Both can be done by weak acids such as citric, maleic, oxalic, or phosphoric acid. EDTA-Fe-Na (ethylene diamine tetra acetic) can be used as an additive since it is suitable for the prevention of the denaturation of the collagen during and after demineralization. In preventing denaturation the ferric ion is especially important. As a further additive glutaric aldehyde can be helpful with protein fixation of collagen fibers.

Bottom Line: Specific pretreatment can significantly increase bond strengths, particularly after long term immersion in water under conditions similar to those in the human body.The bond strength between bone and plastic for example can be increased by a factor approaching 50 (pealing work increasing from 30 N/m to 1500 N/m).This review article summarizes the multi-disciplined subject of adhesion and adhesives, considering the technology involved in the formation and mechanical performance of adhesives joints inside the human body.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Prosthetic Dentistry, Section of Dental Materials, University Hospital of the University of Technology, Aachen, Germany. herli@ukaachen.de

ABSTRACT
Medical implants and prostheses (artificial hips, tendono- and ligament plasties) usually are multi-component systems that may be machined from one of three material classes: metals, plastics and ceramics. Typically, the body-sided bonding element is bone. The purpose of this contribution is to describe developments carried out to optimize the techniques, connecting prosthesis to bone, to be joined by an adhesive bone cement at their interface. Although bonding of organic polymers to inorganic or organic surfaces and to bone has a long history, there remains a serious obstacle in realizing long-term high-bonding strengths in the in vivo body environment of ever present high humidity. Therefore, different pretreatments, individually adapted to the actual combination of materials, are needed to assure long term adhesive strength and stability against hydrolysis. This pretreatment for metal alloys may be silica layering; for PE-plastics, a specific plasma activation; and for bone, amphiphilic layering systems such that the hydrophilic properties of bone become better adapted to the hydrophobic properties of the bone cement. Amphiphilic layering systems are related to those developed in dentistry for dentine bonding. Specific pretreatment can significantly increase bond strengths, particularly after long term immersion in water under conditions similar to those in the human body. The bond strength between bone and plastic for example can be increased by a factor approaching 50 (pealing work increasing from 30 N/m to 1500 N/m). This review article summarizes the multi-disciplined subject of adhesion and adhesives, considering the technology involved in the formation and mechanical performance of adhesives joints inside the human body.

Show MeSH
Related in: MedlinePlus