致炎因素与过度负荷对种植体周围骨吸收影响的动物模型研究

发布时间：2018-07-07 22:47

本文选题：种植体周围炎 + 过度负荷　；参考：《南方医科大学》2014年硕士论文

【摘要】：研究背景种植体周围炎(Peri-implantitis)是指伴有(或不伴有)软组织炎症的种植体周围骨组织的进行性吸收,其发病率为28-56%。种植体周围炎是导致临床种植体失败的主要原因。种植体周围炎具有其临床表现特点,一开始表现为为附着丧失,探诊深度增加,早期骨吸收仅累及牙槽嵴顶,根方仍保持骨结合状态,种植体可以不松动,后期随着周围支持骨的逐渐丧失,牙槽骨高度减低,或可探及较深的种植体周袋,发生种植体松动,从而导致骨结合的失败。后期放射线检查可观察到种植体周围骨组织有透射吸收影,骨吸收的类型可以分类为蝶形、漏斗型或裂隙状骨吸收。种植体周围炎最早由Levignac在1965年观察并描述,后来由Mombelli等人定义为“在特定位点发生的,类似牙周疾病的感染”。这个定义后来发展并更换为“与种植体周围支持骨丧失相关的炎症反应”。在2011年发表的一个共识报告里认为,细菌感染是引起种植体周围骨丧失的始动因素。该报告还特别强调了与种植体周围炎有关的临床特点以及种植体周围炎与牙周炎病因的相似性。然而有些学者却认为,种植体和骨是直接结合的,与具有缓冲作用的牙齿和牙周膜连接方式大不相同,因此与临床相关种植体周围骨丧失的特定病因不一定也是菌斑积聚。所以有人提出了其它原因来支持不可预知的骨丧失,如过度的机械负荷。这些其它原因诱导已经骨结合的界面发生反应性变化,最终导致整个种植体失败。由于所提出的关于种植体周围炎的致病原因研究最多的是菌斑生物膜积聚和过度咬合负载,所以以往动物研究专门关注在这些普遍认为的致病因素上。以往学者通过动物实验和临床检查得出结论,认为在种植体周围感染的过程中,菌斑生物膜的积聚是其原发病因。而对于过度负荷因素对种植体周围骨吸收的影响一直未有定论。Isidor对猴的动物实验研究发现过度负荷对种植体骨结合丧失的影响比菌斑积聚更大；Rosenberg等和Sanz等从临床和微生物学的角度出发,将种植体周围骨吸收划分为细菌性和非细菌性的；而Kozlovsky等通过对犬的研究结果得出,当种植体周围黏膜无炎症状态时,过度负荷增加了骨-种植体接触,并且只是轻度降低了边缘骨高度,而若存在种植体周围炎症时,过度负荷则加重了菌斑引起的骨吸收；Isidor认为过度负荷引起骨整合的丧失,而菌斑积聚引起的是骨组织的吸收而非骨整合的丧失。诱导菌斑积聚多通过在种植体和基台连接处周围结扎丝线或正畸橡皮筋来建立动物模型；丝线结扎诱导法是通过破坏种植体-软组织界面的上皮袖口的封闭作用,从而引起的菌斑堆积、微环境变化进而导致种植体周围软硬组织破坏。而过度负荷一般是由加高咬合或是在两个种植体之间连接弹性装置来实现。目的本实验试图在建立的种植体周围炎动物模型的基础上,通过临床探诊和组织学观察来研究过度负荷对种植体周围骨吸收的影响。材料与方法 1.材料健康成年雄性Beagle犬4只,犬龄16～18个月,体重12.5～14.5kg。购自高要市康达实验动物科技有限公司,所选的实验动物生化指标均正常,神态正常,无急性炎症,无传染性疾病。所有犬牙列完整,无慢性牙周病及龋病,口腔黏膜正常,咬合关系正常。Beagle犬饲养和动物实验手术均在南方医科大学南方医院动物实验研究中心进行。实验选用种植体为Dentium种植系统SuperLine系列型号FX4010SW种植体32颗,规格4.0mm×10mm,大颗粒喷砂及酸蚀(sandblasted, large-grit, acidetched, SLA)表面处理。Dentium种植系统愈合基台32颗,型号HAB402035L。Dentium种植系统分体式六角基台(含基台螺丝)32颗,型号DAB4510HL。 2.实验分组情况拟在种植体植入术后10w安装修复基台,按种植体是否过度负荷和种植体颈部是否结扎丝线这2个处理因素,将每只Beagle犬口内的8颗种植体分为四组,分组具体情况如下：下颌每侧近中2颗种植体安装修复基台后为不加负载,远中2颗种植体利用加高对应上颌咬合获得过度负荷,然后随机选取其中一侧4颗种植体通过在基台颈部缠绕4-0丝线获得感染,另一侧4颗种植体则为非感染侧。这样,每只Beagle犬口内共有4组种植体,每组各2颗,分组为UU(unloaded and uninflamed)、LU (loaded and uninflamed)、UI (unloaded and inflamed)、LI (loaded and inflamed)。 3.动物模型的建立 4只Beagle犬术前禁食24h,禁水4h,按30mg/kg的剂量在静脉注射3%戊巴比妥钠进行全身麻醉后,利用牙挺和牙钳拔除犬双侧下颌共8颗前磨牙。术后使用抗生素进行预防性感染。8w拔牙创愈合后,自牙槽嵴顶切开牙龈,分离粘骨膜瓣。无菌生理盐水冷却下,逐级预备种植窝,在每只Beagle犬的下颌前磨牙区每侧各植入4颗种植体,种植体完全就位后确保种植体颈部顶端与牙槽嵴顶在同一骨水平,安放愈合基台。种植体植入术后10w取下愈合基台,安放修复基台,随机选取一侧的种植体基台颈部结扎4-0丝线,另一侧则不结扎丝线。充填树脂加高远中2颗种植体的对应上颌牙齿的咬合,使上下第一磨牙咬合时可通过厚约1mm的10层渗透性咬合纸,进而使远中2颗种植体获得过度的咬合力。安放修复基台后使用0.05%醋酸洗必泰溶液和儿童软毛刷清洁对照侧未结扎丝线侧的牙列,每周进行1次。加载2个月后心内空气栓塞法处死实验动物。 4.临床指标测量种植体植入后愈合10w,观察种植术区愈合情况。种植体周围无感染,无松动脱落,愈合基台完好。在安放修复基台后2w、4w、6w、8w的时间点对4只beagle犬进行叩诊、松动度检查和种植体周的探诊。选用塑料探针来探查种植体周,使用时垂直进入牙周袋底,力度约为0.2N,检查牙龈指数(GI, gingival index)、改良龈沟出血指数(mSBI, modified Sulcus Bleeding Index)以及牙周探诊深度(PD,probing depth). 5. X-ray观察 4只beagle犬处死后分离出下颌骨,通过放射检查定位,制取独立标本后置于10%福尔马林液中浸泡72h完成初固定。之后将带种植体的独立样本分别用保鲜膜包裹好,采用平行投照的原理,利用数码牙片机观察种植体周围骨组织的情况。 6.制作不脱钙组织切片及组织学观察将完成初固定的标本利用EXAKT300CP组织切割系统修整后完成终固定,梯度酒精逐级脱水,光固化树脂渗透,光照包埋聚合后,利用EXAKT400CS/AW打磨系统和EXAKT300CP组织切割系统切片,电子测量控制系统下磨片,甲苯胺蓝染色,封片,移至光学显微镜下观察并测量兴趣区骨组织-种植体接触率(BIC%, bone-implant contact as percent of the total implant osseous length). 7.统计学分析应用SPSS13.0统计软件对实验获取的各类检测指标的数据进行归类、整合及分析,进行统计学分析。加载后2w、4w、6w、8w,4组探诊的GI、mSBI比较采用多个独立样本非参数检验(K Independent Samples Test)中的多组等级/频数表资料的比较进行统计；加载后2w、4w、6w、8w,4组探诊深度的变化比较采用单个重复测量因素的方差分析；8周后4组骨组织-种植体接触率的比较采用单向方差分析(One-Way ANOVA)。检验水准为α=0.05,当P0.05时,差异被认为无统计学意义；当P0.05时,差异被认为具有统计学意义。结果 1.大体观察所有Beagle犬均于全麻后3～5小时内清醒,清醒后30min内可站立行走,自行进食饮水。拔牙术和种植术后10d内饲喂流食,第10d拆除缝线后恢复饲喂Beagle犬专用饲料,进食饮水无障碍,精神良好,活动正常,体重变化不大,全部存活。种植体植入术后种植体未出现排斥反应,愈合基台均存留。 2.探诊指标测量加载后2w的GI,UU组和LU组之间无显著性差异,UI组和LI组之间无显著性差异,LU组和LI组之间存在显著性差异。加载后2w的mSBI,UU组和LU组之间无显著性差异,UI组和LI组之间存在显著性差异,LU组和LI组之间存在显著性差异。加载后4w的GI和mSBI, UU组和LU组之间存在显著性差异,UI组和LI组之间无显著性差异,LU组和LI组之间存在显著性差异。加载后6w的GI, UU组和LU组之间存在显著性差异,UI组和LI组之间无显著性差异,LU组和LI组之间存在显著性差异。加载后6w的mSBI, UU组和LU组之间存在显著性差异,UI组和LI组之间存在显著性差异,LU组和LI组之间存在显著性差异。加载后8w的GI, UU组和LU组之间存在显著性差异,UI组和LI组之间无显著性差异,LU组和LI组之间存在显著性差异。加载后8w的mSBI,UU组和LU组之间存在显著性差异,UI组和LI组之间存在显著性差异,LU组和LI组之间存在显著性差异。加载后2-8w的PD值通过分析发现,随着加载时间推移,不同处理组的PD值具有显著性差异。通过多重比较方法得出,在2w、4w、6w、8w时,UU组和LU组之间均无显著性差异,UI组和LI组之间均无显著性差异,LU组和LI组之间均具有显著性差异。 3. X-ray检查加载后8w,UU组和LU组的种植体近远中牙槽骨几近与种植体颈部顶端平齐,未见明显吸收,UI组种植体颈部近远中牙槽骨则出现裂隙状透射影,说明种植体颈部已经开始出现骨吸收,LI组跟UI组相比较种植体颈部的透射影呈角形,说明牙槽嵴顶部骨吸收活动更加严重。 4.组织学比较利用显微镜自带图像分析软件观察分析,加载后8w的UU组、LU组、UI组、LI组的平均BIC%为：(83.15±2.47)%,(87.71±1.77)%,(83.58±2.52)%,(86.76±2.06)%,通过分析后比较得出4组之间的差异具有统计学意义,进一步比较后发现UU组和LU组之间存在显著性差异,UI组和LI组之间存在显著性差异,LU组和LI组之间无显著性差异。镜下可观察到：(1)UU组和UI组：骨组织与种植体表面紧密接触,周围可见平行排列的板层骨,同心圆状哈弗氏管散在分布于其中；(2)LU组和LI组：骨组织与种植体表面结合紧密,周围呈致密板层骨结构,骨细胞有规律地分布在板层结构中,哈弗氏管大量形成呈紧密排列状。结论 1. Beagle犬性情温顺,容易饲养,易于操作,体格强健,疾病抵抗能力强,其牙槽骨较宽,骨质致密,与人的牙槽骨较为接近,对于拔牙后延期植入种植体达到骨整合有较为成熟的实验流程,可以成功应用于建立种植体周围炎动物模型的研究。 2.丝线结扎诱导菌斑积聚能导致种植体周围软组织炎症,并增加种植体周围的探诊深度。 3.当种植体周围软组织存在炎症时,种植体颈部骨组织吸收明显。 4.过度负荷会增加骨-种植体接触率,软组织炎症并不影响骨-种植体接触率。
[Abstract]:Background of the study

The peri - implant inflammation is the progressive absorption of peri - implant bone tissue with ( or without ) soft tissue inflammation , the incidence of which is 28 - 56 % . The peri - implant inflammation is the main cause of failure of clinical implant .

This definition was later developed and replaced by " inflammation reactions associated with bone loss associated with peri - implant bone loss " . The report also highlights the clinical features associated with peri - implant bone loss and the similarities between peri - implant and periodontitis . However , some scholars believe that implants and bone are directly bound and are not necessarily associated with bone loss associated with peri - implant bone loss . Other reasons are therefore proposed to support unpredictable bone loss , such as excessive mechanical loads . These other causes induce reactive changes in the interfaces that have been bone - bound , which ultimately lead to failure of the entire implant .

The study of animal experiments and clinical studies concluded that the accumulation of plaque biofilm was the primary cause of infection in peri - implant .
Rosenberg et al . and Sanz et al . , from the perspective of clinical and microbiology , divide the bone resorption around the implant into bacterial and non - bacterial ;
The results from the study of dogs showed that excessive loading increased the bone - implant contact when there was no inflammation in the mucosa around the implant , and only slightly reduced the marginal bone height , whereas in the presence of inflammation around the implant , excessive load increased bone resorption caused by plaque ;
Isidor is of the opinion that excessive loads cause loss of bone integration , and plaque accumulation results in the loss of bone tissue absorption rather than bone integration .

inducing plaque accumulation to build an animal model by ligation of a wire or orthodontic band around the implant and abutment junctions ;
The wire ligation induction method is achieved by destroying the sealing action of the epithelial cuffs of the implant - soft tissue interface , resulting in plaque build up , micro - environmental changes which in turn lead to the destruction of soft and hard tissue around the implant , and the excessive load is generally achieved by a high bite or by connecting an elastic device between the two implants .

Purpose

This study attempted to investigate the effect of excessive load on bone resorption around implants based on the establishment of an animal model of peri - implant inflammation .

Materials and Methods

1 . Materials

Healthy adult male Beagle dogs 4 , dog age 16 - 18 months , body weight 12.5 ~ 14.5kg . The selected experimental animal biochemistry index is normal , normal , no acute inflammation , no infectious disease . All canine teeth are complete , no chronic periodontitis and caries , oral mucosa is normal , bite relation is normal . Beagle dog breeding and animal experiment operation are treated on the surface of Southern Medical University Animal Experimental Research Center .

2 . Experimental grouping

There were four implants in each Beagle dog oral cavity . The four implants in each group were infected by higher jaw occlusion and four implants on the other side were non - infected .

3 . Establishment of animal model

The results showed that there were 8 anterior teeth on the anterior teeth of the dog . After the operation , four implants were removed from the top of the alveolar bone . After the implant was fully seated , four implants were implanted from the top of the alveolar bone . After the implant was fully seated , the top of the implant neck and the alveolar ridge were placed on the same bone level .

4 . Measurement of clinical indicators

The healing of implant was observed after implant implantation . There was no infection in the peri - implant region , no loose shedding , and good healing abutment . At 2w , 4w , 6w and 8w after the implantation of the prosthetic group , four dogs were examined for percussion , loosening and implant weeks . The implant was examined by plastic probe . The force was about 0.2N , the gingival index ( GI ) , the improved gingival sulcus bleeding index ( mSBI , modified Sulcus Index ) , and the periodontal diagnostic depth ( PD ) were improved .

5 . X - ray observations

After 4 dogs were sacrificed , the mandible was separated , and the specimens were placed in 10 % formalin for 72 h to complete initial fixation . Then , the independent samples with implant were wrapped with preservative film , and the bone tissue around the implant was observed by digital dental machine .

6 . Preparation and histological observation of calcium - free tissue

After finishing the initial fixed specimen with EXAKT300CP tissue cutting system , complete the final fixation , gradient alcohol step - by - step dehydration , photo - curing resin infiltration , illumination - embedding polymerization , using EXAKT400CS / AW polishing system and EXAKT300CP tissue cutting system slice , electronic measurement control system to stain and seal , and move to optical microscope to observe and measure the bone tissue - implant contact rate of interest area ( BIC % , bone - implant contact as percent of the total implant contact length ) .

7 . Statistical Analysis

SPSS 13.0 was applied to classify , integrate and analyze the data of various kinds of test indexes acquired by the experiment . The GI and mSBI of 2w , 4w , 6w , 8w , and 4 groups after loading were compared .
After loading 2w , 4w , 6w , 8w and 4 , the variance of probing depth was compared with that of single repeat measurement .
One - way ANOVA was used for the comparison of bone tissue - implant contact rates at 4 groups after 8 weeks . The level of test was 伪 = 0.05 , when P0.05 , the difference was considered to be of no statistical significance ;
When P0.05 , the difference was considered statistically significant .

Results

1 . General observations

All Beagle dogs were conscious in 3 to 5 hours after general anesthesia , and were able to stand and walk within 30 minutes after waking . After extraction and 10 days after implantation , the animals were fed with a diet . After 10 days of extraction , the animals were fed with special feed . After 10 days of removal of the suture , the animals were fed with special feed for Beagle dogs . No obstacle to feeding drinking water , good mental health , normal activity and low body weight , all survived . After implant implantation , no graft rejection occurred and the healing abutment remained .

2 . Measurement of diagnostic index

There was no significant difference in the GI , UU and LU groups of 2w after loading . There was no significant difference between the UI group and the LI group . There was no significant difference between the LU group and the LI group . There was a significant difference between the group of mSBI , UU and LU after loading . There was a significant difference between the UI group and the LI group . There was a significant difference between the LU group and the LI group .

There was a significant difference between the GI and mSBI , UU and LU groups of 4w after loading , there was no significant difference between the UI group and the LI group , and there was a significant difference between the LU group and the LI group .

There was a significant difference between the two groups , namely the GI , UU and LU groups of 6w after loading . There was a significant difference between the LU group and the LI group . There was a significant difference between the LU group and the LI group . There was a significant difference between the UI group and the LI group , and there was a significant difference between the LU group and the LI group .

There was a significant difference between the two groups : the GI , UU and LU groups of 8w after loading . There was a significant difference between the LU group and the LI group . There was a significant difference between the LU group and the LI group . There was a significant difference between the group of mSBI , UU and LU after loading . There was a significant difference between the UI group and the LI group .

The PD values of 2 - 8w after loading were analyzed and found that the PD values of different treatment groups were significantly different with the time of loading . Through multiple comparison methods , there was no significant difference between the UU group and LU group at 2w , 4w , 6w , 8w , there was no significant difference between the UI group and the LI group , and there was significant difference between the LU group and LI group .

3 . X - ray inspection

The alveolar bone near the implant neck was almost flush with the top of the implant neck after loading 8w , UU and LU , but no obvious absorption was observed . The alveolar bone in the proximal part of the implant neck in the UI group appeared to have a fissure - like projection , indicating that the implant neck had begun to have bone resorption , and the LI group had an angle with the UI group to compare the penetration of the implant neck .

4 . Histological Comparison

The mean BIC % of the UU group , the LU group , the UI group and the LI group was ( 83.15 卤 2.47 ) % , ( 87.71 卤 2.52 ) % , ( 86.76 卤 2.06 ) % , ( 86.76 卤 2.06 ) % , and there was a significant difference between the two groups . There was no significant difference between the LU group and the LI group .

The results showed that : ( 1 ) UU group and UI group : the bone tissue was in close contact with the surface of implant body , the peripheral visible parallel lamellar bone , concentric circle Haversian canal scattered among them ;
( 2 ) LU and LI groups : the bone tissue is tightly combined with the surface of the implant body , the surrounding is a compact lamellar bone structure , the osteocytes are regularly distributed in the plate layer structure , and the Haversian canal is formed in a large number of closely aligned shapes .

Conclusion

1 . Beagle dog has the advantages of mild temperament , easy feeding , easy operation , strong physique , strong disease resistance , wide alveolar bone , compact bone , and relatively mature alveolar bone , and can be successfully applied to the research of establishing an animal model around the implant .

2 . wire ligation induces plaque accumulation which can lead to soft tissue inflammation around the implant and increase the depth of probing around the implant .

3 . When there is inflammation in the soft tissues around the implant , the bone tissue of the implant neck is obviously absorbed .

4 . Over - load increases the bone - implant contact rate , and soft tissue inflammation does not affect the bone - implant contact rate .
【学位授予单位】：南方医科大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R783.6

【参考文献】