Nicotine effects on the osseointegration of implants with different treatments / 中国组织工程研究

ABSTRACT

BACKGROUND:Studies have confirmed that nicotine affects the activity of osteoblasts, osteoclasts, fibroblasts and erythrocytes. OBJECTIVE:To study the nicotine effects on osseointegration and the expression of osteoprotegerin and bone morphogenetic protein 2 after implantation of dental implants with surface treatment by sandblasting or acid etching. METHODS:Twenty-four Sprague-Dawley rats were randomly assigned to two groups and received daily injections for 2 weeks as folows Nicotine 2 mg/kg twice for experimental group, saline solution for control group. Then the titanium implants with surface sandblasting or acid etching were implanted into the tibiae folowed by continuous nicotine or normal saline injection. At weeks 2 and 4 after implantation, the implants and surrounding bone tissue were prepared for CT, X-ray and hematoxylin-eosin staining examinations to evaluate bone healing and expression levels of bone-related genes were measured by quantitative RT-PCR. RESULTS AND CONCLUSION: Compared with the control groups, the degree of osseointegration and the expression of osteoprotegerin and bone morphogenetic protein 2 in the experimental groups were decreased significantly (P < 0.05), except that the expression of bone morphogenetic protein 2 in the experimental group with acid etching was not significantly reduced. In addition, the expression of bone morphogenetic protein 2 in the experimental group with acid etching was higher than that in the experimental group with sandblasting at 2 weeks after implantation (P < 0.05). The X-ray and CT show that the quantities of new generation bone and the degree of bone mineralization of the sandblasting group were significant lower than those of the acid etching group under the intervention of nicotine. Hematoxylin-eosin staining showed that the activity and quantity of osteoblasts around the implants down-regulated significantly, but acid etching-treated implants showed better outcomes than sandblasting-treated implants.