Osteoconductive Scaffolds for Bone Augmentation in Guided Bone Regeneration Model

Objectives: To compare the osteoconductivity potential of different scaffolds to enhance vertical bone formation in GBR model. Methods: 15 rats were included. Following exposure and perforation of the calvaria a gold occlusive capsule (7 mm diameter, 7 mm height) was filled with the tested scaffold , laied on the bone and fixed to the bone by fixation screws . Surgical flaps were repositioned and secured. Rats were randomly divided into five groups: (C)-control empty capsule, (COL)- collagen, (TCP)- beta tri-calcium phosphate, (BO)-Bio-oss collagen and (HAF)- hyaluronic acid-fibrinogen. Rats were sacrificed 8 weeks later, and specimens were prepared for histological analysis. Results: The augmented tissue and newly formed bone were quantified by measuring the maximal vertical augmented tissue and bone height in the histological sections. In the C group bone height ranged from 0.5 to 1.4 mm and was similar to the original rats' calvaria. In all experimental groups augmented tissue was noticed and consisted of: residual scaffold, connective tissue and bone. The dimention of the augmented tissue were 5-6 mm in the TCP and BO groups, 4mm in the COL group and 3 mm in the HAF group. However, the vertical bone height was highest in the HAF group (2.88 ± 0.61 mm). This new bone appeared mature, highly vascularised and without inflammatory signs. In the other experimental groups the augmented tissue composed mostly by residual scaffold that was surrounded by connective tissue. Bone height were 2mm and 1.5 mm in the TCP, COL and BO groups respectively. Conclusions: HAF and TCP scaffolds demonsterted osteoconductive potentioal and new bone formation. Scaffolds with slow degradation rate exibited high augmentation tissue that was composed mostly by scaffold residuals and connective tissue.