rabbit

Preliminary study on the osseointegration effects of contactless automated implant cavity preparation via femtosecond laser ablation

AUTHORS

Shanshan Liang, Jianqiao Zheng, and Fusong Yuan

ABSTRACT

Microrobots were used to control the femtosecond laser ablation of bone tissues to prepare implant cavities for dental implant surgery. The method was optimized through depth-of-cut experiments of ex vivo rabbit femurs, and the optimized method was used to prepare implant cavities on the left femurs of eight live rabbits. A power of 10 W and a scanning rate of 4000 mm/s were found to be optimal. After seven days of osteoinduction, the expression of collagen type I was significantly higher in the experimental group than in the control group (manually drilled implant cavities). The bone–implant contacts of the experimental group at 4 and 8 weeks were 9.65% and 23.08%, respectively.

Collagenated Porcine Heterologous Bone Grafts: Histomorphometric Evaluation of Bone Formation Using Different Physical Forms in a Rabbit Cancellous Bone Model

AUTHORS

Rui I. Falacho, Paulo J. Palma, Joana A. Marques, Maria H. Figueiredo, Francisco Caramelo, Isabel Dias, Carlos Viegas, Fernando Guerra

ABSTRACT

Collagenated porcine-derived bone graft materials exhibit osteoconductive properties and the development of different formulations intends to enhance bone regeneration. This study aims to evaluate bone healing in a rabbit cancellous bone defect in response to grafting with different physicochemical forms of heterologous porcine bone. Twenty-six adult male New Zealand White rabbits received two critical size femoral bone defects per animal (n = 52), each randomly assigned to one of the five tested materials (Apatos, Gen-Os, mp3, Putty, and Gel 40). Animals were sacrificed at 15- and 30-days post-surgery. Qualitative and quantitative (new bone, particle and connective tissue percentages) histological analyses were performed. Histomorphometry showed statistically significant differences in all evaluated parameters between mp3 and both Putty and Gel 40 groups, regardless of the timepoint (p < 0.05). Moreover, statistical differences were observed between Apatos and both Putty (p = 0.014) and Gel 40 (p = 0.007) groups, at 30 days, in regard to particle percentage. Within each group, regarding new bone formation, mp3 showed significant differences (p = 0.028) between 15 (40.93 ± 3.49%) and 30 (52.49 ± 11.04%) days. Additionally, intragroup analysis concerning the percentage of particles revealed a significant reduction in particle occupied area from 15 to 30 days in mp3 and Gen-Os groups (p = 0.009). All mp3, Gen-Os and Apatos exhibited promising results in terms of new bone formation, thus presenting suitable alternatives to be used in bone regeneration.

Incorporation of nanosized calcium silicate improved osteointegration of polyetheretherketone under diabetic conditions

Diabetes can impair osteoblastic functions and negatively interfere with osteointegration at the bone/implant interface. Previously, we prepared a nanosized calcium silicate (CS) incorporated-polyetheretherketone (PK) biocomposite (CS/PK) and found that the CS/PK composite exhibited enhanced osteoblast functions in vitro and osteointegration in vivo, but its bioperformance under diabetic conditions remained elusive.

Odanacatib, effects of 16-month treatment and discontinuation of therapy on bone mass, turnover and strength in the ovariectomized rabbit model of osteopenia

Odanacatib (ODN) a selective and reversible cathepsin K inhibitor, inhibits bone resorption, increases bone mass and reduces fracture risk in women with osteoporosis. A 16-month (~7- remodeling cycles) study was carried out in treatment mode to assess the effects of ODN versus ALN on bone mass, remodeling status and biomechanical properties of lumbar vertebrae (LV) and femur in ovariectomized (OVX) rabbits.