A Bone-Like Precoating Strategy for Implants: Collagen Immobilization and Its Mineralization on Pure Titanium Implant Surface

Abstract

Many surface modification strategies are currently of interest in improving integration of implants to bone. An in vitro precoating of a bone-like mineralized layer of immobilized collagen on the implant surface is a potentially valuable approach to improve host acceptance of the implant. The goal of this investigation was to develop a method to precoat in vitro a bone-like mineralized collagen layer on a pure titanium dental implant surface. The study was conducted on acid-etched and nonetched surfaces of screw implants. Initially, a procedure was standardized to self-assemble collagen from a collagen solution. In subsequent experiments, the implant was also placed inside the solution, and after 3 days, collagen was found to be coated on the implant surface. Mineralization of the collagen gel as well as collagen coating on the implant was carried out by calcium phosphate precipitation from a mineralizing solution of calcium chloride containing polyvinyl phosphonic acid and polyaspartic acid, which served as polyanionic additives to help disperse the precipitation and template mineral nucleation. The implant was kept in the mineralizing solution and maintained for 2 weeks in an incubator at 37 degrees C with a phosphate vapor phase generated from a vial containing dihydrogen ammonium phosphate in the incubator. Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analysis confirmed the coated layer to be a biomimetic bone-like mineralized type 1 collagen. Initial studies using osteoblast-like cells indicated cellular attachment on the modified surface. The method appears to be a promising way to generate in vitro a bone-like layer on the implant surface.

Biomimetic Remineralization of Resin-bonded Acid-etched dentin

“…The SBF was buffered to pH 7.4 with 0.1 M Tris Base and 0.1 M HCl and filtered. For biomimetic remineralization, 500 μg/mL of polyacrylic acid (MW 1800; Sigma-Aldrich, St. Louis, MO, USA) and 200 μg/mL of polyvinylphosphonic acid (MW 62,000; Sigma-Aldrich) (Munisamy et al ., 2008; Tay and Pashley, 2008) were added to the SBF as biomimetic analogs, with the pH of the latter adjusted to 7.4.…”

Revisión bibliográfica de Implantología Bucofacial del año 2008: Primera parte

“…Estos tipos de superficies actúan favoreciendo la agregación de componentes inorgánicos y celulares (proteínas y osteoblastos) permitiendo la osteointegración por contacto directo (OCD), lo que facilita una rápida curación ósea y una mayor estabilidad de los implantes sometidos a carga respecto a los implantes con osteointegración a distancia (OD). Finalmente, tanto la OCD como la OD seguirán el patrón normal de osificación centrípeta (56,58,61,62 La capacidad osteoconductora de la hidroxiapatita, del calcio y del colágeno están siendo aplicadas en la superficie de los implantes por su acción estimuladora celular en la interfase hueso-implante (56-58, 60, 61).…”

“…). En la actualidad, también se ha demostrado que las superficies rugosas favorecen el fenómeno de la osteoinducción(58,61,(63)(64)(65)(66), ya que son capaces de estimular la migración y adhesión celulares, acelerando la curación ósea y aumentando la superficie de contacto (SC) entre el implante y el hueso (58, 61, 63-66) (Nosotros no estamos de acuerdo con esta terminología, ya que siendo estrictos, las superficies no influyen de forma directa en la diferenciación de las células madre hacia células osteoprogenitoras).Gurgel y cols. (66) demostraron una mayor SC del implante rugoso tratado mediante oxidación, comparado con implantes de superficie mecanizada.…”

Preparation and in vivo evaluation of apatite/collagen packed composite by alternate immersion method and Newton press

“…Apatite/collagen composite is regarded as an excellent bone‐graft or scaffold material for repair of osseous defect because its composition resembles that of natural bone and facilitates bone regeneration 1. Alternate immersion in calcium ion and phosphate ion solutions is regarded as a simple, cost effective, and reliable method to coat the collagen surface with apatite, thereby forming apatite/collagen composite,2, 3 although several other techniques such as dispersion,4 biomimetic process5–9 and thermal self‐assembly10 exist. The shape and morphology of apatite/collagen composites also vary, including sponge,2 particulate,11 coating,9 and bulk 12.…”