阿仑膦酸钠联合四环素局部应用对延期再植干燥狗牙愈合的影响

目的:探讨阿仑膦酸钠(alendronate,ALN)联合四环素(tetracycline,TET)局部应用对延期再植干燥狗牙愈合的影响。方法:采用成年杂种狗3条,选择上颌双侧第1、2、5牙和下颌双侧第2、3、5牙为受试牙,共18对同名受试牙。随机将每对中的2颗同名受试牙分入实验组或对照组。所有受试牙均先接受根管处理。7d后拔牙,随即自然干燥60min;再植前实验组牙先被置于1mmol/L浓度的ALN溶液中浸泡5min,接着再被置于10ml/L TET溶液中浸泡5min;对照组牙仅被置于1mmol/L浓度的ALN溶液中浸泡5min。植后12周后取出含牙骨块,进行脱钙、制片、HE染色,对牙根的愈合情况进行组织形态学评价。结果:实验组牙骨质愈合的百分比均值高于对照组者,差异无显著性(P>0.05);实验组牙根炎症性吸收的百分比均值低于对照组者,差异有显著性(P<0.05)。结论:与单纯ALN局部应用比较,ALN联合TET局部应用不能增加延期再植干燥牙的牙骨质愈合,但能减少牙根炎症性吸收,有利于延长牙的使用寿命,具有一定的临床价值。     

牙及牙槽外科

智齿拔除后羟基磷灰石恢复牙槽骨高度的临床研究;阿仑膦酸钠对延期再植干燥狗牙愈合的影响;磨除法拔除阻生齿临床效果评价;外伤性脱位牙再植术后的临床观察;下颌牙槽嵴增高术进展     

釉质基质蛋白诱导延迟再植牙牙周愈合的研究

目的：研究应用釉基质蛋白对延迟再植比格犬恒切牙牙周再生的影响。方法：选取3只比格犬的15颗干燥60min的切牙随机分为两组,实验组10颗牙根涂釉基质蛋白;对照组5颗牙根不涂釉基质蛋白,进行再植。8周后处死犬,每隔500μm切取5μm厚的横断切片作组织学观察。结果：与对照组相比,实验组牙再植后能显著地增加牙周膜性愈合的数量（P〈0．001）,并减少替代性吸收（P〈0．001）。结论：釉基质蛋白能对延迟再植牙的牙周愈合有促进作用。     

��������ƶԴ�������Դ�����ƶ�����������Ӱ���о�

目的探讨伊班膦酸钠对正畸源性牙根吸收的影响。方法本实验于2011年6月至2012年1月在山东大学西校区动物实验中心完成。选用30只6周龄雌性SPF级Wistar大鼠,随机分为实验组和对照组,各15只。建立大鼠正畸牙移动模型,安装矫治器前3d实验组于腭侧黏骨膜下局部注射伊班膦酸钠50μL,对照组于相同部位注射生理盐水50μL,每3d注射1次直至实验结束。2组动物分别于安装矫治器后第3、7、14d各处死5只。检测大鼠第一磨牙近中移动距离、牙根吸收指数,并进行牙体牙周联合切片的组织学观察。结果安装矫治器后第7、14d时实验组牙齿移动距离、牙根吸收指数、破牙骨质细胞数及破骨细胞分化因子阳性表达均小于对照组,差异具有统计学意义(P<0.05)。结论局部应用伊班膦酸钠可抑制大鼠正畸牙齿的移动及牙骨质和牙本质的异常吸收,利于牙周组织受正畸力后的改建。     

促进撕脱性损伤牙延期再植后牙周愈合的研究进展#br#

牙撕脱性损伤是牙外伤中预后较差的一种,目前对于恒牙撕脱性损伤的治疗一般采用牙再植术,再植时根面牙周组织活性对其预后至关重要。临床调查显示,撕脱性损伤牙再植多为延期再植,离体牙根面牙周膜在干燥状态下脱水坏死是导致术后病理性牙根吸收的主要原因。国际牙外伤协会建议在延期再植时采取适当措施,促进再植牙的牙周愈合再生,减少病理性吸收,延长再植牙使用寿命。文章结合2020版国际牙外伤协会撕脱性损伤牙治疗指南对现有促进撕脱性损伤牙延期再植后牙周愈合相关研究做一综述,包括根面处理、药物及干细胞治疗在牙再植术中的应用。     

再植牙牙根替代性吸收的发生与防治

近年来由于交通事故不断上升 ,使外伤脱位牙的发生率逐渐上升。据报道 ,在所有外伤中 ,造成恒牙脱位的占 0 .5 %～ 1 6 % [1] 。牙外伤脱位最常用的治疗方法是牙再植术。在临床上 ,牙根替代性吸收是再植牙常见的一个并发症。本文进一步阐明牙根替代性吸收发生的机制以及相应的防治措施综述如下。1　牙根替代性吸收的发生机制　　造成牙再植失败的原因很多 ,其中炎症性吸收和替代性吸收是造成牙再植失败的主要原因。根骨粘连也叫替代性吸收。根骨粘连的过程是在牙糟壁上形成的骨小梁 ,逐渐生长 ,越过牙周膜间隙 ,与牙根表面融合。然后这些骨…     

儿童50 颗恒牙再植后的回顾性研究

目的:分析再植牙的预后及影响预后的相关因素,观察再植后牙根吸收出现时间及影响因素.方法:对2000～2006 年于北京大学口腔医学院儿童口腔科注册的系统病历中,观察期≥6 个月的全脱位牙再植病历进行回顾性研究,记录患者及再植牙信息.应用卡方检验和生存分析(cox regression)进行统计学分析.结果:符合纳入标准的外伤病历39 份,涉及再植牙50 颗.牙周膜愈合的发生率为18%,牙根吸收发生率为82%,替代性吸收是最常见的牙周组织预后形式(64%).牙根发育情况和保存方式与牙周组织预后具有显著相关性;牙根发育情况、牙髓治疗时机可以影响牙根吸收出现的时间(P<0.05).结论:替代性吸收是再植牙最常见的牙周组织预后形式.再植牙牙根发育情况和保存方式与牙周组织预后具有显著相关性.牙根发育情况、牙髓治疗时机可以影响牙根吸收出现的时间.     

阿仑膦酸钠对骨质疏松种植体骨结合影响的力学研究

目的 通过力学评估研究全身应用骨吸收抑制剂阿仑膦酸钠对骨质疏松模型种植体周围骨整合的影响.方法 27只5月龄日本大耳白兔随机分成3组,每组9只:单纯卵巢切除组(OVX组),伪手术组(S组),卵巢切除加阿仑膦酸钠组CALN组).卵巢摘除后12周,双侧股骨远心端、胫骨近心端植入4枚种植钉,ALN组腹腔给予阿仑膦酸钠,OVX...     

局部注射阿仑膦酸钠对大鼠正畸牙移动的影响

目的观察局部注射阿仑膦酸钠对大鼠正畸牙移动及牙周组织的影响。方法32只Wistar大鼠分为对照组和低剂量、中剂量、高剂量三个实验组,使用40g力牵其左侧上颌第一磨牙近中移动,实验中分别将生理盐水、0.02mmol/L、0.1mmol/L、0.5mmol/L的阿仑膦酸钠溶液注射入各组大鼠上颌第一磨牙近中腭侧的粘骨膜下,注射于实验前3d开始,每3天一次,每次50μl。分别在0、1、3、7、14、17、21d时取模法测量大鼠牙移动量。第21天取上颌组织块经固定、脱钙、脱水、包埋后切片,HE染色观察牙周组织变化,TRAP染色观察压力区破骨细胞数、破牙骨质细胞数,比较各组间是否有差异。结果①各实验组大鼠第一磨牙移动距离显著低于对照组,并随药物浓度增高其抑制效果增强。②实验组压力区破骨细胞数和破牙骨质细胞数显著低于对照组。结论局部注射不同浓度阿仑膦酸钠能获得不同的抑制牙齿移动的效果,可应用于临床中作为一种增强支抗的手段。     

年轻恒牙再植术与延迟再植

牙齿完全脱出(avulsion)是最严重的一种牙齿损伤,可以造成牙周韧带撕裂、牙髓组织丧失血供及牙骨质损伤.年轻恒牙牙根尚未发育完成,而且牙周膜具有弹性,水平撞击常可导致牙齿完全脱出,上颌中切牙最好发.牙齿完全脱出的治疗方法是牙齿再植术.再植牙愈合和修复是一个复杂的过程,受多种因素影响.再植牙的预后包括牙髓组织预后和牙周组织预后两方面.成人再植牙多数都不能成功保留活髓,再植牙预后多指牙周组织预后.牙再植后牙周组织愈合方式分为牙周膜愈合(healing with a normal periodontal ligament)、表面吸收愈合(healing with surface resorption,repair-related resorption)、牙齿固连或替代性吸收(healing with ankylosis,replacement resorption)、炎性吸收(healing with inflammatory resorption,infection-related resorption).通常所说的再植牙存活指牙周膜愈合,是最佳的愈合方式.     

Periodontal healing of extracted dogs' teeth air-dried for extended periods and soaked in various media

Abstract The aim of this study was to determine the periodontal healing of replanted dogs’ teeth which, after extended extra-oral dry times, had been soaked in various media before replantation. Incisors and premolars of beagle dogs were root canal treated, extracted and bench dried. The teeth were grouped according to dry times of 30, 45 and 60 minutes. Each group of teeth was soaked in one of three media, Hank's balanced salt solution, Via Span (Belzer UW-CSS, Dupont Pharmaceuticals), or Conditioned Medium (supernatant of confluent culture of human gingival fibroblasts) for 30 minutes before replantation. Controls consisted of teeth extracted and replanted without drying or soaking (negative control), and bench-dried teeth replanted without soaking in the media (positive control). The dogs were killed 6 months after replantation of the teeth, which were prepared for histologic evaluation. Five um cross-sections (every 70 Jim) of the root and surrounding tissue were evaluated for healing/resorption according to Andreasen's criteria. The best healing occurred for the roots which had been immediately replanted. Healing in the positive control groups decreased with increased dry time. For the 30–minute dry time groups, soaking in media had no beneficial effect on periodontal healing compared with the controls. Soaking in ViaSpan resulted in an increased healing incidence for both the 45- and 60- minute bench-dried groups while soaking in the other media had no consistent beneficial effect. It appears from this study that an avulsed tooth that has been left dry for 30 minutes should be replanted immediately without soaking. However, teeth that have been dry for 45 or 60 minutes would benefit from soaking for 30 minutes in ViaSpan.     

Periodontal and pulpal healing of monkey incisors preserved in tissue culture before replantation.

The effect of delayed replantation and tissue culture as a prevention against root resorption was examined in green Vervet monkeys (Cercopithecus aethiops). Extracted incisors were kept in tissue culture medium (Eagle's medium) for 5--14 days before replantation. The extra-alveolar dry period before tissue culture ranged from to 0 to 60 min. Incisors not subjected to tissue culture served as controls. The animals were sacrificed 8 weeks after replantation. The following histologic parameters were registered for each tooth: surface resorption, inflammatory resorption, replacement resorption (ankylosis), downgrowth of pocket epithelium, and periapical inflammatory changes. The evaluation of the pulp included the extent, recorded in mm, of pulp survival. Histometric evaluation showed that teeth immediately placed in tissue culture medium for 5--14 days showed improved periodontal healing, exhibiting significantly less inflammatory resorption than control teeth immediately replanted. Also the extent of pulp survival was significantly increased in teeth replanted after tissue culture. Teeth bench-dried for 60 min and thereafter placed in tissue culture medium also showed a significant reduction in the amount of inflammatory resorption and increased amount of pulp survival compared with control teeth replanted after the 60-min dry extra-alveolar period. Replacement resorption (ankylosis) was found in all teeth in both groups.     

The effect of topical minocycline on replacement resorption of replanted monkeys' teeth

Abstract – Tetracycline has been reported to possess antiresorptive properties in addition to antimicrobial actions. Systemic administration of tetracycline showed variable results in the control of replacement resorption after replantation with good results in half of the cases, and almost no healing in the rest. The purpose of this study was to evaluate histologically the effect of topically applied minocycline on replacement resorption of replanted monkeys' teeth. Thirty‐two roots from seven monkeys were endodontically treated aseptically to prevent inflammatory resorption of pulpal origin, a common sequela after avulsion injury. Teeth were then extracted as atraumatically as possible. Teeth in the negative control group (10 roots) were replanted almost immediately, while teeth in the positive control group (12 roots) were allowed to bench‐dry for 1 h prior to replantation, both without further treatment. Teeth in the experimental group (10 roots) were bench‐dried for 1 h, rinsed with saline, and then immersed in 1 ml of 50 mg ml^?1 minocycline hydrochloride for 5 min before replantation. No splinting was used. After 12 weeks, the animals were sacrificed and histological sections were prepared and evaluated according to a morphometric analysis modified from that described by Andreasen (1987) as complete healing, inflammatory resorption, and replacement resorption. Kruskal–Wallis test showed significant differences among the three groups in all the three healing categories. Further analysis with Mann–Whitney U‐test showed teeth in the negative control group to have significantly higher complete healing and significant lower unfavorable healing, comprising of replacement resorption and inflammatory root resorption than the positive control group and the minocycline group. Topical application of minocycline to the root surface appeared to result in slightly higher occurrence of complete healing (32.46%) compared to the delayed replantation group with no minocycline treatment (positive control) (16.58%), but the difference was not statistically significant (P = 0.09).     

Histopathological evaluation of the effects of variable extraoral dry times and enamel matrix proteins (enamel matrix derivatives) application on replanted dogs' teeth

The extra‐alveolar dry period and storage medium in which the tooth was kept prior to replantation remain the critical factors affecting the survival and regeneration of the damaged periodontium. When the replantation is delayed, replacement root resorption is the most common complication following replantation of an avulsed tooth. The aim of this histological study was to evaluate the periodontal healing of replanted dogs' teeth after 20 min (short) and 60 min (long) extraoral dry time with and without the application of enamel matrix proteins. Eighty mature premolar roots (40 teeth) maxillary and mandibular premolars were extracted, the root canals were accessed, instrumented, and filled using a lateral condensation technique, and the access cavity was restored with amalgam. Each root was randomly assigned to one of experimental groups: Groups I and II: Roots were replanted after an extraoral dry time of 20 min. In group II, Emdogain^® (Biora, Malmo, Sweden) was applied directly to the external root surface with complete coverage. Groups III and IV: Roots were replanted after an extraoral dry time of 60 min. In group IV, Emdogain^® was applied to the whole external root surface before replantation. Roots that replanted within a total extraoral dry time of 10 min were used as negative controls, while those replanted after 90 min of extraoral dry time were assigned as positive controls. After 4 months, the dogs were euthanized, and the maxillary and mandibular processes were processed for histology and microscopically evaluated. Statistical analysis showed no significant differences (P = 0.1075) among the experimental groups. The results of this study show that 20 min of extraoral dry time is as detrimental to the PDL cells as 60 or 90 min of extraoral dry time, with avulsed dogs' teeth, even when replanted with an inductive material such as EMD. This study provides strong evidence in relation to the threshold of the extraoral dry time of avulsed teeth, suggesting that the extraoral dry time threshold of PDL cell viability is significantly less than that which current guidelines promote.     

The effect of intracanal anti-inflammatory medicaments on external root resorption of replanted dog teeth after extended extra-oral dry time.

The prognosis of replanted teeth depends on several factors, the most important being the length of extra-oral dry time. Studies show that after 60 min dry time, root resorption is predicted. Immediate intracanal placement of Ledermix, a paste containing triamcinolone (corticosteroid) and demeclocycline (tetracycline) has been shown to inhibit root resorption after extended dry time. However, discoloration is possible from the tetracycline in Ledermix. To evaluate the individual influence of corticosteroid and tetracycline on external root resorption after extended extra-oral dry time. Sixty-nine premolar roots of four beagle dogs were extracted and instrumented with NiTi files. Group 1 (negative control) was immediately replanted after root filling with GP and sealer; Group 2 (positive control) was root filled with GP and sealer and replanted after 60 min dry time; In groups 3-5, the canals were filled with Ledermix, Triamcinolone, and Demeclocycline, respectively, and replanted after 60 min dry time. After 4 months, the dogs were sacrificed and the roots were examined histologically for type of healing (favorable or unfavorable) and remaining root diameter. The groups treated with Ledermix, Triamcinolone and Demeclocycline had statistically significantly more favorable healing (75.8%; 69.8%; 52.4%) and more remaining root structure (5.59; 5.48; 5.09) than the group filled with GP and sealer (positive control) (0; 1.15). Corticosteroids were as effective as Ledermix at inhibiting external root resorption.     

Periodontal healing of replanted dog teeth stored in Viaspan, milk and Hank's balanced salt solution

Abstract This study examined, histologically, periodontal healing and root resorption of replanted dogs teeth stored in Viaspan for different time periods and compared these healing patterns to those after storage in milk or Hank's balanced salt solution (HBSS). Seventy-two beagle incisors were endodontically treated, extracted, randomly divided and placed in Viaspan or milk for 6, 12, 24 and 36 h, and Viaspan or HBSS for 36, 48, 72 and 96 h, after which they were replanted. Four negative control teeth were immediately replanted while four positive controls were allowed to dry for one hour before replantation. All replanted teeth were splinted for 14 days. Two months after replantation the clogs were killed and the teeth histologically examined for healing of the supporting tissues. For Viaspan neither replacement nor inflammatory root resorption was seen after 6 and 12 h storage. A statistically significant rise in the incidence of replacement resorption was seen at 24, 36 and 48 h which decreased again at 72 and 96 h to levels equal to storage for 6 and 12 h. The occurrence of inflammatory root resorption was low and significantly increased only at 48 h after which it decreased significantly again. Viaspan proved superior to milk as a storage medium. Teeth stored in HBSS showed healing results similar to those stored in Viaspan.     

Periodontal healing of replanted dog teeth stored in Viaspan, milk and Hank's balanced salt solution.

This study examined, histologically, periodontal healing and root resorption of replanted dogs teeth stored in Viaspan for different time periods and compared these healing patterns to those after storage in milk or Hank's balanced salt solution (HBSS). Seventy-two beagle incisors were endodontically treated, extracted, randomly divided and placed in Viaspan or milk for 6, 12, 24 and 36 h, and Viaspan or HBSS for 36, 48, 72 and 96 h, after which they were replanted. Four negative control teeth were immediately replanted while four positive controls were allowed to dry for one hour before replantation. All replanted teeth were splinted for 14 days. Two months after replantation the dogs were killed and the teeth histologically examined for healing of the supporting tissues. For Viaspan neither replacement nor inflammatory root resorption was seen after 6 and 12 h storage. A statistically significant rise in the incidence of replacement resorption was seen at 24, 36 and 48 h which decreased again at 72 and 96 h to levels equal to storage for 6 and 12 h. The occurrence of inflammatory root resorption was low and significantly increased only at 48 h after which it decreased significantly again. Viaspan proved superior to milk as a storage medium. Teeth stored in HBSS showed healing results similar to those stored in Viaspan.     

The effect of intracanal Ledermix on root resorption of delayed-replanted monkey teeth

Abstract – Progressive root resorption is one of the common sequelae in replanted teeth, which is detrimental to their long‐term prognosis. Ledermix paste, with its composition of triamcinolone acetonide and demethylclortetracycline, has been shown to inhibit inflammation and the associated hard tissue resorption. This study evaluated the effect of immediate intracanal Ledermix on root resorption of delayed‐replanted monkey teeth. A total of 36 roots were root canal treated. For the experimental group, intracanal Ledermix was placed prior to extraction and replantation after 1‐h bench dry. The positive control group was root filled and replanted after 1 h while the negative control group was root filled and replanted immediately. The monkeys were sacrificed after 12 weeks. The H&E histological tissue specimens were prepared and evaluated using a method modified from that of Andreasen's morphometric analysis, as favorable or complete healing and unfavorable healing, comprising inflammatory root resorption and replacement resorption. The results were analyzed using Kruskal–Wallis and Mann–Whitney U‐tests as well as Wilcoxon signed ranks test. The negative control group produced highly significant favorable healing and unfavorable healing as compared to the Ledermix group (P = 0.000). The Ledermix group only showed significantly higher occurrence of complete healing (35.46%) compared to the positive control group (16.58%) (P = 0.037) but there were no significant differences in the inflammatory root resorption and replacement resorption. Nevertheless, when the latter two unfavorable healing patterns were combined, there was a significantly lower overall unfavorable healing in the Ledermix group (64.54%) when compared to the positive control group (83.43%) (P = 0.037). This unfavorable healing outcome in the Ledermix group, however, was not significantly different from the favorable healing outcome with the same treatment modality (P = 0.110).     

The effect of saline storage before replantation upon dry damage of the periodontal ligament

Abstract The effect of 30 min of saline storage before replantation of teeth, which had been dried out for 30 min, was studied in 10 Green Vervet monkeys (Cercopithecus aethiops). Maxillary central incisors were extracted and dried out for 30 min, after which 1 incisor was replanted and the other transferred to a saline solution for 30 min before replantation. No splinting or endodontic treatment was carried out. The teeth were examined after 8 wk. Histometric analysis showed identical extent of root resorption in the 2 groups, with ankylosis being the dominant resorption type, and with very limited pulpal repair in either group. It is concluded that saline storage under the experimental conditions chosen had no effect on development of root resorption or pulpal repair, presumably because 30 min dry storage had inflicted close to maximal damage on the periodontal ligament at the root surface. On the other hand, it is of clinical importance that a certain delay in the replantation procedure does not influence periodontal and pulpal healing, as long as the tooth is kept in saline storage. This suggests that replantation under these conditions can be reserved for dental professionals, rather than favoring immediate replantation by anyone ‘on-the-spot’.