Comparison of the early production of extracellular matrix on dense hydroxyapatite and hydroxyapatitecoated titanium in cell and organ culture

Dental implant induced bone remodeling and associated algorithms

“…The peak mechanical stresses in the bone caused by these two loading components can superimpose with each other, causing excessive stress developed in the dental implant and its interface with the surrounding bones, thereby resulting in mechanical damage and bone loss. For this reason, it was suggested (LeGeros, 1993a;Courteneyharris et al, 1995;Debruijn et al, 1993;van Blitterswijk et al, 1994) to use smooth endosseous implant necks to enable the sliding motion between the implant and the bone, which to a certain extent buffers the severe concentration of mechanical stresses.…”

“…The roughened implant surface can be highly irregular and increases the surface area, thereby facilitating osseointegration and promoting the early healing in the peri-implant osteogenesis (Winter et al, 2004;Liu and Niebur, 2008). Although roughened titanium implants remain a common option, there is an increasing trend of using roughened HA coated implants for its more extensive cell attachment (Debruijn et al, 1993;van Blitterswijk et al, 1994;Courteneyharris et al, 1995).…”

“…Hansson (2003) suggested that the loading on a dental implant consists of two components in the vertical and the horizontal directions (Courteneyharris et al, 1995). The peak mechanical stresses in the bone caused by these two loading components can superimpose with each other, causing excessive stress developed in the dental implant and its interface with the surrounding bones, thereby resulting in mechanical damage and bone loss.…”

Thermal Analysis of Amorphous Phases in Hydroxyapatite Coatings

“…Adsorbed water is removed from the surface at temperatures <200°C and from pores at temperatures up to 500°C, and then structural water is removed at temperatures >900°C. [16][17][18][19] If the HPO 4 2− specie substitutes for the PO 4 3− specie in the lattice, then heating results in the formation of Ca 2 P 2 O 7 , which is also accompanied by a weight loss. 20 Additional heating then causes a transformation to tricalcium phosphate.…”

“…3 The amorphous phase, when located on the outer surface of a coating, promotes the growth of osseous tissue, compared to crystalline sintered hydroxyapatite. 4 However, the high dissolution of the amorphous phase 5 could influence implant stability. The location of the amorphous phase can especially be detrimental, in the long term, if the amorphous phase is located in regions that are adjacent to the substrate, where preferential dissolution of the amorphous phase can lead to delamination and, hence, implant failure.…”