The Effect of Gold Nanoparticles and Apricot Kernel Extract on the Osseointegration of Dental Implants - A Rabbit Model

The osseointegration of dental implants is critical to their longevity and success. Various factors such as surface modifications, both additive and subtractive, systemic drug administration, growth factors, and plasma derivatives can influence osseointegration.

This study aimed to study the effects of gold nanoparticles and aqueous extract of apricot kernels on the osseointegration of titanium implants in the tibia of rabbits.

Apricot kernels were dried, grounded, and dissolved in water to obtain an aqueous extract. It was filtered and stored in the refrigerator at 4^oC. Gold nanoparticles (AuNPs) were prepared by mixing 3 ml of 0.02 mM hydrogen tetrachloroaurate with 1 ml of olive leaf extract. The mixture was stirred vigorously for 15 minutes on a heater stirrer at 50^oC. Titanium screw implants were sterilized in an autoclave at 120^oC with 15 pounds per square inch for 30 minutes. Sterilized implants were stored in sealed containers until use.

The study was carried out at the College of Veterinary Medicine, University of Mosul, Iraq. The ethical approval for the study was obtained from the institutional animal care and use committee, College of Veterinary Medicine, University of Mosul, Mosul, Iraq, on 15/04/2023 on reference no UM.VET.2023.013. Nine healthy male adult white New Zealand rabbits aged between 10-12 months were utilized for the study. Three pure titanium implants, each of a type, were placed in each tibia. The implants were categorized as follows: control group (18 uncoated implants) and experimental group (36 coated implants). The implant placement was divided into three groups: controls with uncoated implants (n=18), AuNPs-coated implants (n=18), and apricot kernel extract-coated implants (n=18). General anesthesia was induced by intramuscular injection of ketamine hydrochloride 50mg (1ml /kg of body weight) plus xylazine 2% (0.2 ml /kg of body weight). The AuNPs-coated implants were implanted in the superior osteotomy site in the tibia. The apricot kernel extract-coated implants were implanted in the inferior osteotomy site and the uncoated implants were implanted in the middle osteotomy sites. Histological and histomorphometric tests were performed on all bone implant blocks at one-week, two-week, and three-week intervals after implant placement. The results were evaluated based on the amount of bone formation, cellular components, and inflammation. Tabulated data were statistically analyzed using SPSS v23.0 (IBM, Armonk, NY) using ANOVA with a statistical significance of p <0.05

We observed a significant amount of osteogenesis with reduced inflammation in AuNPs-coated implants and apricot kernel extract-coated implants compared to untreated implants. The osteoclastic activity was significantly higher in untreated implants than the treated implant sites. A statistically significant association was observed between coated implants and untreated implants.

The application of gold nanoparticles and aqueous extract of apricot kernels appears to be promising in reducing inflammation and improving bone apposition on the titanium implant surface. However, this preliminary investigation warrants further research.