[Bone cement adhesion on ceramic surfaces - surface activation of retention surfaces of knee prostheses by atmospheric plasma versus thermal surface treatment]. / Zementhaftung auf keramischen Oberflächen - Oberflächenaktivierung der Retentionsflächen von Knieendoprothesen durch atmosphärisches Plasma vs. thermischer Oberflächenbehandlung.
Z Orthop Unfall
; 153(2): 146-52, 2015 Apr.
Article
en De
| MEDLINE
| ID: mdl-25874392
AIM: CoCrMo alloys are contraindicated for allergy sufferers. For these patients, uncemented and cemented prostheses made of titanium alloy are indicated. Knee prostheses machined from that alloy, however, may have poor tribological behaviour, especially in relation to UHMWPE inlays. Therefore, for knee replacement cemented high-strength oxide ceramic prostheses are suitable for allergy sufferers and in cases of particle-induced aseptic loosening. For adhesion of bone cement, the ceramic surface, however, only exposes inefficient mechanical retention spots as compared with a textured metal surface. Undercuts generated by corundum blasting which in the short-term are highly efficient on a CoCrMo surface are not possible on a ceramic surface due to the brittleness of ceramics. Textures due to blasting may initiate cracks which will weaken the strength of a ceramic prosthesis. Due to the lack of textures mechanical retention is poor or even not existent. Micromotions are promoted and early aseptic loosening is predictable. Instead silicoating of the ceramic surface will allow specific adhesion and result in better hydrolytic stability of bonding thereby preventing early aseptic loosening. Silicoating, however, presupposes a clean and chemically active surface which can be achieved by atmospheric plasma or thermal surface treatment. METHOD: In order to evaluate the effectiveness of silicoating the bond strengths of atmospheric plasma versus thermal surface treated and silicate layered ZPTA surfaces were compared with "as-fired" surfaces by utilising TiAlV probes (diameter 6 mm) for traction-adhesive strength tests. After preparing samples for traction-adhesive strength tests (sequence: ceramic substrate, silicate and silane, protective lacquer [PolyMA], bone cement, TiAlV probe) they were aged for up to 150 days at 37â°C in Ringer's solution. RESULTS: The bond strengths observed for all ageing intervals were well above 20 MPa and much higher and more hydrolytically stable for silicate layered compared with "as-fired" ZPTA samples. CONCLUSION: Silicoating may be effective for achieving high initial bond strength of bone cement on surfaces of oxide ceramics and also suitable to stabilise bond strength under hydrolytic conditions as present in the human body in the long-term. Activation by atmospheric plasma or thermal surface treatment seems to be effective for activation prior to silicoating. Due the proposed silicate layer migration, micromotions and debonding should be widely reduced or even eliminated.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Plasma
/
Siloxanos
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Propiedades de Superficie
/
Cementos para Huesos
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Cerámica
/
Adhesividad
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Polimetil Metacrilato
/
Artroplastia de Reemplazo de Rodilla
/
Materiales Biocompatibles Revestidos
/
Calefacción
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
De
Revista:
Z Orthop Unfall
Asunto de la revista:
ORTOPEDIA
/
TRAUMATOLOGIA
Año:
2015
Tipo del documento:
Article
Pais de publicación:
Alemania