AnnaKarin Lundgren

Guided jaw-bone regeneration using an experimental rabbit model

The aims of this study were to evaluate the space-maintaining capacity of two biocompatible barrier materials and to assess the effect of barrier occlusiveness on the amount of regenerated bone. Defects were prepared in the edentulous area on both sides of the maxillas in 22 rabbits. The rabbits were divided into three groups. Gore-Tex augmentation material (GTAM) (ePTFE)-barriers were placed to cover the experimental defects and compared with totally occlusive or perforated titanium foils and uncovered control defects respectively. After four weeks of healing, histological analyses and morphometrical measurements demonstrated that the amount of regenerated bone tissue was about the same underneath the collapsed GTAM-barriers as in the controls. The highest degree of regeneration was obtained in defects underneath the titanium foils, particularly if they were perforated, whether or not they were covered by GTAM-barriers. It was concluded that the space-maintaining properties of a barrier may be at least as important as barrier occlusiveness when regenerating bone defects.

An experimental rabbit model for jaw-bone healing

The purpose of this investigation was to study the structural and topographical bone anatomy of the right and left edentulous areas between the incisors and molars in the rabbit maxilla with regard to the symmetry of the bone, and to assess the degree of spontaneous healing of surgical defects. Anatomical and radiographic examinations together with analysis of serial histological ground sections in ten rabbits disclosed no statistically significant differences between the two sides regarding the different bone-tissue structures, i.e. they exhibit a sufficient degree of symmetry to serve as a useful bilateral test-control model. Surgical defects were made on one side of the jaw (test side) in a group of eight rabbits. This resulted in an average loss of 17% of the total bone volume after a healing period of four weeks as compared to the untreated control side. It was concluded that surgically-created defects do not show completely spontaneous healing. From a histological section of the test side, it was possible to redraw the original bone contour by interpolation between unaffected areas of bone, coronal and apical to the defect. This means that the test side of this model can also serve as its own control with regard to the amount of regenerated tissue, given that there is unaffected bone, coronal and apical to the defect.