Lasak (Czechia)

The aim of this study was to evaluate the osteoconductive properties of synthetic porous hydroxyapatite prepared by low-temperature microwave processing OssaBase® HA (SPHA) in comparison with biological apatite, non-sintered deproteinized bovine bone Bio-Oss® (DBB). The materials were implanted into the bone sockets of the tibia of Beagle dogs for 3 and 6 months. The bone response to granules of the materials of similar sizes was compared. Histological analysis of the specimens with histomorphometry was performed at different times after in vivo implantation. Based on the histological analysis, the level of bone formation in the spaces between the implanted granules and through the interconnected pores of both implanted materials within a cortical region was significantly higher (bone area ingrowth 72–85%) than within a cancellous bone site (bone area ingrowth 16–28%) at three and six months after implantation. According to our study, the bioactive and osteoconductive properties (bone implant contact and bone area ingrown) of the synthetic porous hydroxyapatite are very high and comparable with the biological apatite, non-sintered deproteinized bovine bone. The favourable influence of the high specific surface area and carbonate content of the synthetic, porous hydroxyapatite on bone formation was confirmed.

This study was carried out to quantify the effect of an alkali-modified surface on implant stability during healing using an animal model. A total of 24 screw-shaped, self-tapping, commercially pure titanium dental implants, divided into a test group (implants with an alkali-modified surface or "biosurface") and a control group (implants with a turned, machined surface) were inserted without pretapping in the tibiae of 3 beagle dogs. The resonance frequency analysis method was used to measure the implant stability quotient (ISQ) 0, 1, 3, 9, and 12 weeks after implantation. The animals were sacrificed after 2, 5, and 12 weeks, and the bone-implant contact (BIC%) was evaluated histomorphometrically. The difference in the osseointegration rates (deltaISQ/deltahealing time) between the implants with alkali-modified surface (biosurface) and those with a turned, machined surface was evaluated as a mean of 0.843 ISQ/week within the first 9 weeks of healing. The mean increase in the secondary implant stability was found to be proportional to the mean increase in the BIC at healing period earlier than 5 weeks. The characteristics that differed between the implant surfaces, ie, specific surface area, contact angle, and hydroxylation/hydration, may represent factors that influence the rate of osseointegration and the secondary implant stability. The alkali-treated surface enhances the secondary stability in the early stages of healing compared to the turned, machined surface, as a consequence of faster BIC formation.