Experimental And Clinical Application Study Of Osteogenesis Effect On Extraction Socket Preservation With Different Material

Alveolar bone is the basis of teeth,and it is the basis of denture prosthesis,too.There were a lot of patients whose alveolar bone absorbed when they extracted their teeth,then this kind of alveolar severity affected the manufacture of artificial teeth.The implanted denture need full alveolar bone furthermore.The scholars have done many research in order to prevent extraction socket bone to be absorbed.Keeping bone of extraction sockets position is the hotpoint of studys.The experiment selected dogs to do this test.We extracted dog’s teeth roots of mandibular premolars,then implanted callback bone crumbs and different proportion artificial hydroxyapatite into the sockets.The collagen membrane was covered on the sockets and the wound was sewed up.The radiographic,bone density and histological observations were performed at8weeks and12weeks after surgery;Collagen membrane and gelatin sponge were cut and implanted into rabbits extraction sockets,the mandibles were removed to take radiographic and histology examination after8to12weeks,we could contrast the effect of sockets preservation;We summarized our clinical patients who had preservated their extraction sockets and finished implanted denture.We cut the bone samples of extraction sockets with trephine and made the hard bone tissue slices to test the new bone and the metabolize of artificial material.Part I Experimental study of osteogenesis effect on extraction socket preservation with different materialIn this experiment,we chosed dogs in order to evaluate the osteogenesis effect in the extraction socket preservation with different bone materials.The mesio-root of second,third,forth premolars of dogs were extracted from mandibular in3dogs.In the extraction sockets,we implanted different bone materials and covered with a collagen membrane(groupⅠ:dogs callback bone crumbs;groupⅡ:hydroxyapatite;groupⅢ:75%bone crumbs add25%hydroxyapatite;groupIV:50%bone crumbs add50%hydroxyapatite; groupV:25%callback bone crumbs add75%hydroxyapatite). The radiographic, bone density and histological observations were performed at8weeks and12weeks after surgery.In the experiment, we found the top of mandibular specimens were a little depressed.The bone density of12weeks extraction socket specimens implanting same material were higher than8weeks specimens.The histological observation could draw a conclusion that the more artificial material in the extraction sockets,the higher artificial material remains.The percent of newly formed bone in the12weeks extraction sockets which implanted75%auto-callback bone crumbs and25%hydroxyapatite was55.3±5.6,it was higher than other teams.We can drew a conclusions that the auto-callback bone crumbs and hydroxyapatite biomaterial which were implanted into extraction sockets immediately preserved the socket contour.It enabled newly formed bone in the extraction sockets for future implant site preparation.Part II Experimental study of the protective effect of gelatin sponge and collagen membrane in rabbits’extraction socketsWe wanted to explore the protective effect of gelatin sponge and Collagen membrane in the rabbit extraction sockets. Six big white ear rabbits have been extracted both mandibular incisors respectively.No.1and No.2rabbits’ left extraction sockets were filled with gelatin sponge and their right extraction sockets were filled with Collagen membrane;No.3and No.4rabbits’ left extraction sockets were vacant as control groups,their right extraction sockets were filled with Collagen membrane;No.5and No.6rabbits’ left extraction sockets were filled with gelatin sponge,their right extraction sockets were vacant as control groups.Killed No.1、3、5and No.2、4、6rabbits respectively on week8、12,the mandibles were removed to take radiographic and histology examination.The experiment results indicated that collagen membrane and gelatin sponge have little difference in the effect on the bone mineral density from radiographic examination,and the histological sections show that both materials can lead to osteogenesis phenomenon.From this experiment,we could drew conclusions that collagen membrane and gelatin sponge both have protective effect on the extraction sockets,and there are not obvious differences between them. Part III Clinical application study of experiment socket preservation in implantation surgeryThe purpose of this clinical experiment was to evaluate the effect of extraction socket preservation which implanted with different materials. In this experiment,50out-patients was chosed to extract teeth roots through micro-wound,Bioss and hydroxyapatite materials were implanted into extraction sockets,the wounds were covered with gelatin membrane and sewed up.The bone sample of extraction socket were drilled with hole saw after5-6months,then the bone hard tissue slices were made to research new bone formation and hydroxyapatite metabolize.From this experiment, we observed that the bone of extraction sockets were preservation effective,the width could adjust to the needs of clinical teeth implantation.From the bone hard tissue slices,we could observed that new bone came into being in the extraction sockets,no matter what materials were implanted.New bone mixed among hydroxyapatite granule,and the bone quantity of roots direction was more than the top.The bone samples which were implanted Bioss could observed more new bone than others.we could drew a conclusion that Bioss and hydroxyapatite materials could preserve the bone of extraction sockets when they were implanted into the sockets.