טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentRozitsky Doron
SubjectBone Regeneration in Dehiscence-Type Defects Following
Implantation of Beta Tri-Calcium Phosphate with
Hydroxyapatite Plus Biphasic Calcium
Sulfate: An Experimental Study
DepartmentDepartment of Medicine
Supervisor Professor Eli Machtei
Full Thesis textFull thesis text - English Version


Abstract

Buccal dehiscence defects present a major problem in implant dentistry. Two treatment modalities groups have been used in order to regenerate these defects: I: Guided Bone Regeneration. II: Bone Grafts.

In this present study we combined two Alloplastic bone grafts - Biphasic Calcium Phosphate (BCP) and Biphasic calcium sulfate (BCS) - in order to benefit from the unique characteristic

of each material and to create an optimal bone regeneration material. We wish to experimentally compare the materials to commercially available collagen membrane (positive control) and to shame operation (negative control).

Two healthy mongrel dogs were used in this study. On each animal, following extractions, standardized buccal dehiscence defects were surgically created on the buccal aspect of the mandibular and maxillary premolars sites. These procedures were staggered in the two dogs, so that to create different observation periods (6, 8, 10, 12 weeks).

At 12 weeks from baseline the dogs were sacrificed and the jaws were scanned by Computed Tomography. The jaws were then histological processed for light microscopy. The samples underwent Histomorphometric Analysis and the following measurements were recorded: 1. Bone Density: the percent of newly formed bone (woven bone lamellar bone) 2. Height (μm) and Area (μm2) of the newly formed bone.

In general, bone density in the Experimental (E) group and Positive Control (PC) group was higher than the Negative Control (NC) group. The % bone density was not very different between the time points thus suggesting early bone regeneration. Histological observation revealed a similar degree of maturation from week 6 to week 12 in all groups.

The height and area of the newly formed bone in the E and PC groups were notably higher than the NC group. Also, the E group had higher values of new bone height and area compared to the PC group in most of the time points. Overall a continuous increase of the height and area of the newly formed bone was observed throughout the healing periods, both in the mandible and maxilla. The Spiral CT macroscopic observations revealed that greater bone fill occurred in the E group followed by PC group and NC group.

In conclusion the results of the present study confirmed the efficacy and safety of BCP plus BCS for bone regeneration in dehiscence type extraction socket defect.