羟磷灰石颗粒和人工牙根植入狗牙槽窝的比较

材料和方法以5只狗作为研究对象,拔除下颌左右两侧第2,3,4前磨牙和第1磨牙。人工牙根植入后比齿槽嵴低2mm～3mm,对侧植入羟磷灰石颗粒,压实到齿槽嵴水平。两种方法各交替植入10个牙槽窝,相邻的牙槽窝(20个)作为对照组。术后注射抗生素,以软食喂养。前半年每4周照X片一次,后一年每8周照片一次,测量齿槽嵴高度;在同样的时间用卡尺测量齿槽嵴厚度。在4周、8周和18个月期间获取标本。比较颊、舌侧齿槽嵴高度。结果对照组牙槽窝,10天后完全愈合,4周时有新生肉芽组织,上面有正常粘膜层覆盖。齿槽嵴高度和厚度与术后立刻测量无差别。12周时齿槽嵴颊侧高度和厚度均有吸收,舌侧无变化。拔牙后6个月期间齿槽嵴高度和厚度明显减少,以后减慢。颊侧高度和厚度比舌侧减少3mm,呈凹形。舌侧为凸形。     

拔牙后牙槽窝即刻植入纳米羟基磷灰石的临床观察

目的:研究拔牙后即刻植入纳米羟基磷灰石颗粒预防术后牙槽骨吸收,保持牙槽嵴高度的临床疗效。方法:选择16例需同时拔除下颌两侧相同部位后牙的患者,按左右分组,左侧为拔牙后立即填塞颗粒型纳米羟基磷灰石,右侧为拔牙后传统搔刮血块充盈对照。4周、12周分别复诊,摄X线片检查。对牙槽窝的愈合,牙槽嵴高度进行观察。结果:16例患者创口愈合良好。两组比较,12周后实验组X线片见牙槽窝处的X线阻射影与周围牙槽骨密度相近,界限不清,恢复的牙槽嵴与周围基本平齐,牙槽高度恢复良好。对照组牙槽嵴高度明显降低,实验组牙槽嵴高度降低不明显。结论:拔牙创内即刻植入纳米羟基磷灰石不影响创口愈合,能促进新骨的形成,很好地维持牙槽嵴高度,为以后进行义齿修复提供一个良好的基骨条件。     

Choukroun富血小板纤维蛋白对兔拔牙窝愈合修复的影响

目的：探讨Choukroun富血小板纤维蛋白植入兔拔牙窝对牙槽骨修复的影响。方法：取大耳白兔15只,随机分成实验组5只,阳性组5只,阴性组5只,拔除右侧上、下颌中切牙后,实验组植入Choukroun富血小板纤维蛋白（PRF）,阳性组植入羟基磷灰石生物陶瓷（骨粉）,并以自然愈合拔牙窝为阴性对照,用X线及组织形态学方法评价兔上下颌切牙拔牙窝的愈合情况。结果：术后1、2、4周剩余牙槽嵴的相对长度变化为：实验组〉阳性组〉阴性组,差别有统计学意义（P〈0.05）;且实验组拔牙窝内新生骨组织数量质量均好于阳性组和阴性组。术后8、12周,实验组和阳性组剩余牙槽嵴的相对长度变化及骨组织修复情况无明显差异。结论：PRF独立做为移植充填材料能够有效保存拔牙窝牙槽嵴长度,促进组织修复。     

成骨诱导剂对拔牙创愈合的影响

目的 探讨以明胶海绵为载体,地塞米松、维生素C和β-甘油磷酸钠组成的成骨诱导剂对拔牙创愈合和牙槽嵴形态改建的影响。方法选用50只家兔,拔除双侧上颌第一前磨牙,右侧拔牙创内填入载有成骨诱导剂的明胶海绵,作为实验侧;左侧填入空载明胶海绵,作为对照侧。拔牙后第1、2、4、8、12周各处死10只动物,取双侧牙槽骨标本,拍摄X线片,并测量骨缺损区新骨密度;用组织学方法评价拔牙创愈合情况;并于12周时,测量拔牙区牙槽嵴高度吸收值。结果X线片骨密度测量显示：术后2、4、8、12周,实验侧骨密度值均高于对照侧,差异有统计学意义（P<0.01）。组织学检查显示：实验侧拔牙创内成骨现象较对照侧早,成骨细胞分化和增殖更活跃。
12周时实验侧牙槽嵴高度吸收值小于对照侧,差异有统计学意义（P<0.01）。结论 由地塞米松、β-甘油磷酸钠和维生素C组成的成骨诱导剂能促进拔牙创愈合,加速成骨和骨改建。     

拔牙位点保存

目的：探讨拔牙位点保存在种植体植入之前保存拔牙后的牙槽嵴和软组织、预防拔牙后的牙槽嵴吸收,并改善骨和软组织质量的效果。方法：29例前牙和前磨牙单颗牙位点,拔牙后即刻向拔牙窝内植入去蛋白牛骨基质,游离移植腭粘膜瓣覆盖并初期创口关闭。6个月之后植入种植体,4个月之后修复。测量骨的颊舌向厚度和高度变化,以及龈乳头的高度变化。结果：牙槽窝粘膜及骨愈合良好,成功完成最终种植修复。结论：位点保存技术可以成功实现拔牙窝骨愈合,减少因拔牙造成的骨缺损,有利于提高种植的成功率,降低GBR的必要性。     

植物血球凝集素（PHA）在拔牙位点保存中的可行性研究

目的：探讨局部应用PHA对拔牙创愈合的影响。方法：选用健康大耳白兔30只,雌雄不限,随机分为实验组15只、对照组15只;拔除右上颌中切牙后,棉球压迫止血,血凝块形成后于实验组拔牙窝的局部牙槽嵴周围及血凝块内注射PHA溶液,对照组注入等量的生理盐水,所有兔子每隔2天注射一次,连续3次。于术后1周、2周、4周、8周、12周每组分别处死3只兔子,行大体观察、影像学观察及组织病理学观察。结果：实验组与对照组之间剩余牙槽嵴相对长度的差异无统计学意义（P＞0.05）;术后HE染色实验组与对照组的成骨活动未见明显差异,但同期相比实验组拔牙窝内的新生毛细血管较对照组多;术后12周的Masson染色实验组与对照组的新生骨中胶原的成熟度亦未见明显差别。结论： PHA可以促进拔牙窝内毛细血管的新生,但对剩余牙槽嵴的保存未见明显作用。     

大鼠下颌切牙拔出后剩余牙槽嵴吸收模型的建立

目的:建立大鼠切牙拔除后剩余牙槽嵴吸收的实验动物模型并探讨其发生机制。方法:选用健康雄性Wistar大鼠30只,局麻下齐龈缘磨除右下颌切牙牙冠,每3天磨除1次,共3次,最后磨除后3d拔除右下颌切牙,术后0、1、2、4、8、12周分别处死大鼠。用软X线摄片测量大鼠下颌剩余牙槽嵴的长度和保存率,组织学方法评价大鼠下颌切牙拔牙窝的愈合情况。对18只健康雄性Wistar大鼠通过HE染色观察磨除牙冠后的不同时期牙周组织形态学改变。结果:牙槽嵴长度:4、8、12周拔牙侧与非拔牙侧相比明显降低(P<0.05);拔牙4周后牙槽嵴保存率明显降低。组织形态学:拔牙后2周,拔牙窝内可见新生骨,残存的血凝块减少;拔牙后4周骨改建活跃;拔牙后8周,拔牙窝内充满新生骨;拔牙后12周,新生骨和周围牙槽骨界限不清。牙冠磨除后,牙周组织出现水肿,主纤维束断裂,丧失功能排列,血窦增加,随时间改变逐渐加重。结论:可以采用拔除大鼠切牙的方法建立剩余牙槽嵴吸收的动物模型。     

局部注射葛根素对鼠拔牙后剩余牙槽嵴吸收影响的实验研究

目的观察中药葛根素对鼠拔牙后剩余牙槽嵴吸收的影响作用。方法制作大鼠下颌中切牙缺失模型,于剩余牙槽嵴的粘膜下注射葛根素,用X线片测量大鼠相对剩余牙槽嵴高度和骨密度值,HE染色观察不同时期剩余牙槽嵴的组织学形态改变。结果实验组剩余牙槽嵴相对高度均大于对照组（P〈0.05）;除一周组外,其余各实验组剩余牙槽嵴光密度测量值均大于对照组（P〈0.01）;组织学观察可见实验组大鼠剩余牙槽嵴表面的成骨质量较对照组高,骨吸收程度较对照组少。结论将葛根素注射于拔牙窝周围能够抑制剩余牙槽嵴的吸收并保存牙槽嵴的高度。     

胶原蛋白海绵对大鼠拔牙后牙槽窝愈合过程的影响

目的 ：探讨胶原蛋白海绵对拔牙创牙槽窝愈合过程的影响。方法 ：取健康雌性SD大鼠16只，首先建立大鼠拔牙模型，实验侧（右）牙槽窝内填入胶原蛋白海绵，对照侧（左）作空白处理。于拔牙术后1、2、4、8周处死大鼠，观察牙槽窝成骨情况，利用实时定量PCR检测实验侧与对照侧成骨相关基因表达变化。采用SPSS 19.0软件包进行统计学分析。结果：术后实验侧牙槽窝较对照侧愈合明显好，实验侧及对照侧组织中Osterix、Runx2及Vegf均有表达，实验侧组织相关基因在术后1、2、4、8周不同时间点的表达水平显著高于对照侧（P<0.05）。结论：胶原蛋白海绵填塞拔牙创牙槽窝可在一定程度上促进牙槽窝早期骨愈合，这一过程可能与胶原蛋白海绵调节成骨相关基因表达水平有关。     

牙槽嵴保存术在牙周感染位点中的应用：从软硬组织再生到后续种植修复

牙周炎会导致牙周软硬组织破坏,其感染位点在拔牙后往往会存在硬组织缺损及软组织缺陷等问题,影响后续种植修复。牙槽嵴保存术可以在拔牙同期对牙槽窝进行处理,促进牙槽窝的重建并减少牙槽嵴的吸收,实现软硬组织的保存。本文拟对牙周感染位点的牙槽嵴保存术,兼顾其术后软组织改变以及对后续种植影响,从感染对牙槽窝愈合的影响、感染位点行牙槽嵴保存术的疗效以及感染位点牙槽嵴保存术的影响因素三方面进行综述。     

前牙根端囊肿合并感染致骨缺损拔牙后位点保存的临床应用

目的:观察因根端囊肿合并感染致牙槽骨缺损后拔牙同期植入Bio-Oss Collagen加用GBR技术,对牙周软硬组织的保存效果。方法:因有根端囊肿合并感染而拔牙的28例患者随机分为两组,实验组拔牙后牙槽窝中植入Bio-Oss Collagen胶原骨,其上覆盖Bio-gide膜行位点保存,对照组拔牙后不做处理。结果:术后观察28例患者创口均为一期愈合,实验组软硬组织位点保存良好,为延期种植修复提供了足够的骨量。结论:牙槽骨缺损后拔牙同期行位点保存可提供足够的牙槽骨高度与宽度及周围软组织的量,使之外形丰满,为延期种植打下美学修复成功的基础,提高患者满意度。     

The effect of simvastatin on remodelling of the alveolar bone following tooth extraction

Suppression of residual ridge resorption after tooth extraction is a hot spot in dental research. Recently, simvastatin was reported to influence bone turnover by stimulating bone formation. In this study, the effect of simvastatin application on residual ridge resorption following tooth extraction was investigated. Sixty male Wistar rats were randomly divided into experimental and control groups (n=30). Polylactic acid/polyglycolic acid copolymer carriers, with or without simvastatin, were implanted into extraction sockets of right mandibular incisors. The rats were killed at 1, 2, 4, 8 or 12 weeks after implantation. The relative height of the residual alveolar ridge was significantly greater in the experimental compared to the control group at 2, 4, 8 and 12 weeks. The bone mineral density in the experimental group was significantly higher than that in the control group at 4, 8 and 12 weeks. A larger newly formed bone island was observed in the experimental group at 4 weeks, and higher bone formation rate and quality were found than in the control group at different time points except 1 week. The findings indicate that local application of simvastatin would effectively preserve the residual alveolar bone by promoting bone formation in the extraction socket.     

Socket grafting with the use of autologous bone: an experimental study in the dog

Background: Studies in humans and animals have shown that following tooth removal (loss), the alveolar ridge becomes markedly reduced. Attempts made to counteract such ridge diminution by installing implants in the fresh extraction sockets were not successful, while socket grafting with anorganic bovine bone mineral prevented ridge contraction. Aim: To examine whether grafting of the alveolar socket with the use of chips of autologous bone may allow ridge preservation following tooth extraction. Methods: In five beagle dogs, the distal roots of the third and fourth mandibular premolars were removed. The sockets in the right or the left jaw quadrant were grafted with either anorganic bovine bone or with chips of autologous bone harvested from the buccal bone plate. After 3 months of healing, biopsies of the experimental sites were sampled, prepared for buccal–lingual ground sections and examined with respect to size and composition. Results: It was observed that the majority of the autologous bone chips during healing had been resorbed and that the graft apparently did not interfere with socket healing or processes that resulted in ridge resorption. Conclusion: Autologous bone chips placed in the fresh extraction socket will (i) neither stimulate nor retard new bone formation and (ii) not prevent ridge resorption that occurs during healing following tooth extraction. To cite this article:
Araújo MG, Lindhe J. Socket grafting with the use of autologous bone: an experimental study in the dog.
Clin. Oral Impl. Res. 22 , 2011; 9–13.
doi: 10.1111/j.1600‐0501.2010.01937.x     

Porcine‐Derived Xenograft Combined with a Soft Cortical Membrane versus Extraction Alone for Implant Site Development: A Clinical Study in Humans

Background: An adequate alveolar crest is essential for implant placement in terms of esthetics and function. The objective of this randomized clinical trial was to compare the preservation of the alveolar ridge dimensions following tooth extraction using porcine‐derived xenograft combined with a membrane versus extraction‐alone (EXT) sites. Methods: Fifteen patients who required double extraction of contralateral premolars and delayed implant placement were randomly selected to receive both ridge‐preservation procedure and EXT. The test sites (alveolar ridge preservation [ARP]) included 15 sockets treated using a corticocancellous porcine bone xenograft (OsteoBiol® Gen‐Os; Tecnoss srl, Giaveno, Italy) associated with a soft cortical membrane (OsteoBiol® Lamina; Tecnoss srl), while the corresponding control sites (EXT) were left without grafting for EXT. Horizontal and vertical ridge dimensions were recorded at baseline and 6 months after extractions. Results: After 6 months, the EXT sites showed a significantly greater reabsorption of the buccolingual/palatal dimension of the alveolar ridge (3.7 ± 1.2 mm) compared with the ARP sites (1.8 ± 1.3 mm). The mean vertical ridge height reduction in the control sockets was 3.1 ± 1.3 mm at the buccal sites and 2.4 ± 1.6 mm at the lingual sites compared with 0.6 ± 1.4 and 0.5 ± 1.3 mm, respectively, in the test sockets. The differences between test and control sockets were not significant for the mesial and distal measurements. Conclusions: The placement of a porcine xenograft with a membrane in an extraction socket can be used to reduce the hard tissue reabsorption after tooth extraction compared with EXT.     

Ridge alterations following implant placement in fresh extraction sockets: an experimental study in the dog

OBJECTIVE: To study dimensional alterations of the alveolar ridge that occurred following implant placement in fresh extraction sockets. MATERIAL AND METHODS: Five beagle dogs were included in the study. In both quadrants of the mandible, incisions were made in the crevice region of the third and fourth pre-molars. Buccal and minute lingual full-thickness flaps were elevated. The mesial root of the four pre-molars root was filled and the teeth were hemi-sected. Following flap elevation in (3)P(3) and (4)P(4) regions, the distal roots were removed. In the right jaw quadrants, implants with a sand blasted and acid etched (SLA) surface were placed in the fresh extraction sockets, while in the left jaws the corresponding sockets were left for spontaneous healing. The mesial roots were retained as surgical control teeth. After 3 months, the animals were examined clinically, sacrificed and tissue blocks containing the implant sites, the adjacent tooth sites (mesial root) and the edentulous socket sites were dissected, prepared for ground sectioning and examined in the microscope. RESULTS: At implant sites, the level of bone-to-implant contact (BC) was located 2.6+/-0.4 mm (buccal aspect) and 0.2+/-0.5 mm (lingual aspect) apical of the SLA level. At the edentulous sites, the mean vertical distance (V) between the marginal termination of the buccal and lingual bone walls was 2.2+/-0.9 mm. At the surgically treated tooth sites, the mean amount of attachment loss was 0.5+/-0.5 mm (buccal) and 0.2+/-0.3 mm (lingual). CONCLUSIONS: Marked dimensional alterations had occurred in the edentulous ridge after 3 months of healing following the extraction of the distal root of mandibular pre-molars. The placement of an implant in the fresh extraction site obviously failed to prevent the re-modelling that occurred in the walls of the socket. The resulting height of the buccal and lingual walls at 3 months was similar at implants and edentulous sites and vertical bone loss was more pronounced at the buccal than at the lingual aspect of the ridge. It is suggested that the resorption of the socket walls that occurs following tooth removal must be considered in conjunction with implant placement in fresh extraction sockets.     

羟基磷灰石人工骨微粒植入牙槽窝的临床应用研究

目的 :研究拔牙后即刻植入羟基磷灰石微粒人工骨预防术后并发症及牙槽骨吸收的临床疗效。方法 :3 1例患者拔牙后牙槽窝内即刻植入羟基磷灰石微粒人工骨 ,术后对患者拔牙创出血、干槽症、牙槽嵴高度等项进行观察并于术后、术后 4周、12周复诊进行临床及X线片检查。结果 :3 1例患者创口愈合良好 ,术后无出血、无干槽症发生 ,X线片见牙槽窝内羟基磷灰石存在 ,牙槽高度恢复良好。结论 :拔牙创内即刻植入羟基磷灰石人工骨不影响创口愈合 ,能很好地维持牙槽嵴高度 ,为人工义齿的修复创造条件     

Local application of simvastatin to rat incisor sockets augments bone

Decrease of the alveolar ridge after tooth extraction causes difficulties in prosthodontic treatment, especially in implant supported prostheses. Statins, which are inhibitors of cholesterol synthesis and therapeutic drugs for hypercholestemia, stimulate BMP-2 expression in osteoblasts. The purpose of the present study was to examine how local application of simvastatin, one of the statins, to the tooth socket after tooth extraction affects alveolar bone. A mixture of lactic acid/glycolic acid copolymer (PLGA), alpha-tricalcium phosphate (alpha-TCP), calcium carbonate was prepared as a carrier for simvastatin. Ninety-six male Wistar rats, 10 weeks old, were used. After right mandibular incisor extraction, they were divided into eight groups and tooth sockets were treated differently: no treatment (control), PLGA carrier only, or PLGA containing 0.1, 0.25, 0.5, 1.0, 2.0, and 4.0 mg simvastatin, respectively. They were sacrificed at 4 and 8 weeks. Bone mineral content (BMC) of the alveolar ridge was measured with dual-energy X-ray absorptiometry and histological analyses were performed. All groups treated with simvastatin showed higher BMC compared to the control group and PLGA carrier group at 4 and 8 weeks. Histological analyses revealed that the thickness of cortical bone of the statin group increased compared to the control group at 4 and 8 weeks; however, newly-formed bone in the tooth socket of the statin group was less than in those of the control group and PLGA carrier group. The results of this study show that local application of simvastatin may enhance bone formation and preserve the alveolar ridge after tooth extraction.