| Summary: | 碩士 === 臺灣大學 === 臨床牙醫學研究所 === 98 === In recent years, the number of adult patients seeking orthodontic treatment has increased significantly, therefore the orthodontists face challenges in moving the dentition with compromised periodontal support. The orthodontic tooth movement could be facilitated if the alveolar ridge is preserved after tooth extraction. The techniques of guided tissue regeneration have been extensively used in periodontal regeneration. Many biomaterials can provide necessary mechanical support and cell adhesion for bone tissue regeneration, whereas they cannot guide cellular phenotype as growth factors can. Chitosan, a natural polysaccharide biomaterial, exhibits nontoxicity, biodegradability, biocompatibility, and antibacterial properties. The aim of this animal study was to assess the effect of glucosamine, i.e. chitosan monomer, on alveolar bone healing of extraction socket. The study was conducted on the teeth (p1~p4 in mandible and p1~p3 in maxilla) of 2 Mongrel dogs in a split-mouth design. Immediately after tooth extraction, the mesial sockets of the second and third mandibular premolars and the second maxillary premolar were filled with the mixture of glucosamine powder and bone marrow aspirate from femur (experiment group I). The distal sockets of the second and third mandibular premolars and the second maxillary premolar were filled with glucosamine powder only (experiment group II). For each group, the experimental procedures were dome at different time for histomorphometric examination at 3 observation time-point of 30, 120, and 180 days. The extraction sockets at contra-lateral side without glucosamine fillings served as a control group. Moreover, the process of bone repair in extraction socket was examined by using the technique of fluorochrome sequential labeling. After the animals were sacrificed, the specimens were processed for examination by fluorescence microscopy and for paraffin sections and stained with haematoxylin-eosin. The results showed: (1) In the experimental sockets, especially filled with glucosamine and bone marrow aspirate (group I), the signs of bone formation were obvious and the number of proliferating cells were higher than that in control group. (2) The size of bone trabeculae in experimental sockets was larger compared to the control group. (3) Both the histological examinations and the observations via fluorochrome labeling revealed that the alveolar sockets heal from peripheral to the central and from apical to the coronal part of the socket. (4) All the sockets healed completely, and no significant difference was noted among the experimental and control groups after an observation period of 180 days.
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