Nano-chitosan/bone morphogenetic protein gel prevents absorption of rat’s alveolar ridge / 中国组织工程研究

ABSTRACT

BACKGROUND:Absorption and atrophy of the alveolar ridge always happen after tooth extraction. There are stil a lot of difficulties to be worked out to prevent the atrophy of the alveolar ridge. OBJECTIVE:To investigate the effect of the nano-chitosan/bone morphogenetic protein hydrogel on preventing absorption of the residual alveolar ridge of the rats. METHODS:Total y 54 Sprague-Dawley rats were divided randomly and equal y into three groups. A model of residual alveolar ridge was made by extraction of the left central incisor. Nano-chitosan bone morphogenetic protein hydrogel was implanted into the rat’s alveolar fossa of the experimental group;the alveolar fossa of the control group was implanted with nano-chitosan hydrogel;the alveolar fossa of the blank group was implanted with nothing. Rat’s mandible was ful y dissected after 3, 6, 9 weeks, respectively. Molybdenum target X-ray examination and pathological observation were evaluated. RESULTS AND CONCLUSION:At weeks 3, 6, 9 postoperation, the residual alveolar ridge was absorbed to different degrees, which was milder in the experimental group than the cotrol group and blank group (P<0.05). After 3 weeks, in the blank group, less new bone formed, but bleeding and a large amount of inflammatory cells were visible; in the control group, a few of osteoid tissues and lymphocytes were found; in the experimental group,new bone formed and a small amount of inflammatory cells were observed. After 6 weeks, new bone formed obviously in the experimental group, a little new bone formed in the control group, but less new bone formed in the blank group. After 9 weeks, a large amount of new bone formed in the experimental group with good osteogenic ability; only a few of new bone formed in the control and blank groups. Nano-chitosan/bone morphogenetic protein hydrogel can be used to prevent the absorption of the residual alveolar ridge after tooth extraction.