Effects of alendronate on bone healing after tooth extraction in rats

Oral Diseases (2010) 16 , 674–685 Objectives: Tooth extraction has been identified as an important risk factor for bisphosphonate‐induced osteonecrosis of the jaw. Therefore, the main goal of this study was to determine the effects of alendronate on healing of the extraction socket and on interdental alveolar bone after tooth extraction in rats. Materials and methods: Animals were injected subcutaneously with vehicle or alendronate for 3–4 weeks before the first mandibular molar was extracted and these treatments were continued during post‐extraction periods of 10, 21, 35 and 70 days. Mandibles were processed to evaluate healing of the extraction socket and adjacent alveolar bone by assessing bone formation, bone resorption and vascularity by histomorphometric techniques. Results: Alendronate decreased new woven bone formation, blood vessel area, perimeter and number in the extraction socket at 10 days postextraction, but not at later time points. Furthermore, alendronate‐treated rats had increased interdental alveolar bone volume and height only at 10 days postextraction. In addition, a 2.5‐fold increase in the percentage of empty osteocyte lacunae was found in alveolar bone of alendronate‐treated rats only at 10 days postextraction. Conclusions: Alendronate transiently decreases bone formation and vascularity in the extraction socket and delays the removal of interdental alveolar bone after tooth extraction in rats.     

Dynamics of bone tissue formation in tooth extraction sites. An experimental study in dogs

OBJECTIVES: The aim of the present experiment was to study events involved in the healing of marginal, central and apical compartments of an extraction socket, from the formation of a blood clot, to bone tissue formation and remodeling of the newly formed hard tissue. MATERIAL AND METHODS: Nine mongrel dogs were used for the experiment. The fourth mandibular premolars were selected for study and were divided into one mesial and one distal portion. The distal root was removed and the socket with surrounding soft and mineralized tissue was denoted "experimental unit". The dogs were killed 1, 3, 7, 14, 30, 60, 90, 120 and 180 days after the root extractions. Biopsies including the experimental units were demineralized in EDTA, dehydrated in ethanol and embedded in paraffin. Serial sections 7 microm thick were cut in a mesio-distal plane. From each biopsy, three sections representing the central part of the socket were selected for histological examination. Morphometric measurements were performed to determine the volume occupied by different types of tissues in the marginal, central and apical compartments of the extraction socket at different intervals. RESULTS: During the first 3 days of healing, a blood clot was found to occupy most of the extraction site. After seven days this clot was in part replaced with a provisional matrix (PCT). On day 14, the tissue of the socket was comprised of PM and woven bone. On day 30, mineralized bone occupied 88% of the socket volume. This tissue had decreased to 15% on day 180. The portion occupied by bone marrow (BM) in the day 60 specimens was about 75%, but had increased to 85% on day 180. CONCLUSION: The healing of an extraction socket involved a series of events including the formation of a coagulum that was replaced by (i) a provisional connective tissue matrix, (ii) woven bone, and (iii) lamellar bone and BM. During the healing process a hard tissue bridge--cortical bone--formed, which "closed" the socket.     

Timeframe of socket cortication after tooth extraction: A retrospective radiographic study

Objectives

To assess the timeframe between tooth extraction and radiographically detectable socket cortication in humans.

Methods

Two hundred and fifty patients with a CT scan ≤36 months after tooth extraction were included. First, three orthoradial multiplanar reconstruction slices, representing the major part of the extraction socket, were scored regarding the degree of bone healing as (i) healed, that is, complete/continuous cortication of the socket entrance, or (ii) non‐healed. Thereafter, based on the results of all three slices, the stage of cortication of the extraction socket, as one unit, was classified as (i) non‐corticated, that is, all three slices judged as non‐healed, (ii) partially corticated, that is, 1 or 2 slices judged as non‐healed, or (iii) completely corticated, that is, all three slices judged as healed. The possible effect of several independent parameters, that is, age, gender, timeframe between tooth extraction and CT scan, tooth type, extent of radiographic bone loss of the extracted tooth, tooth‐gap type, smoking status, presence of any systemic disease, and medication intake, on cortication status was statistically evaluated.

Results

Three to 6 months after tooth extraction, 27% of the sockets were judged as non‐corticated and 53% were judged as partially corticated. After 9–12 months, >80% of the sockets were corticated, while some incompletely corticated sockets were detected up to 15 months after extraction. Each additional month after tooth extraction contributed significantly to a higher likelihood of a more advanced stage of cortication, while radiographic bone loss ≥75% significantly prolonged cortication time; no other independent variable had a significant effect.

Conclusions

The results indicate a considerably long timeframe until complete cortication of an extraction socket, that is, 3–6 months after tooth extraction 3 of 4 sockets were still not completely corticated, and only after 9–12 months, complete cortication was observed in about 80% of the sockets.     

Analysis of the pattern of the alveolar ridge remodelling following single tooth extraction

Introduction: Tooth extraction is followed by marked osseous changes of the residual alveolar ridge including severe bone alterations both in height and in width. However, such remodelling could jeopardize the subsequent implant insertion for two main reasons. Firstly, the absence of adequate bone levels makes implant placement impossible; secondly, aesthetic problems in the fabrication of implanto‐supported restoration could be caused by serious bone re‐absorption. Thus, it is of crucial importance that the dental surgeon knows how the alveolar crest changes when a single tooth has been removed. The aim of this study was to evaluate the pattern of alveolar crest remodelling observed in a single intercalated area of tooth extraction after at least a period of 6 months of healing, using standardized photos of model casts. Material and methods: Among the patients who were treated for a single intercalated tooth extraction during the last 2 years at the department of dentistry at Versilia Hospital, Lido di Camaiore (Lucca), Italy, we selected 50 patients. The amount of alveolar crest remodelling was assessed on standardized photos of study models. All measurement were recorded on an Excel sheet (Excel, Windows XP^®) and each value was multiplied by the enlargement index so that true values of re‐absorption could be obtained. Finally, we have calculated the percentage of amount of alveolar crest remodelling and shifting of alveolar crest. Results: We calculated the percentage of buccal remodelling and alveolar crest shift. The buccal re‐absorption was 19.4±9.4% at mesial point, 39.1±10.4% at midpoint and 20.3±10.7% at distal level. Moreover, the shift of the alveolar crest was 59.1±11.2% at mesial point, 64.8±10.5% at the midpoint and 56±12.5% at distal point. Conclusions: This study confirmed that buccal wall tends to re‐absorb after the extraction according to a specific pattern. Thus, the re‐absorption at the midpoint represent the double of bone loss at the distal and the mesial points. Furthermore, we have observed first how the alveolar crest shifts placing along the more lingual/palatal line which divides the original alveolar crest into three parts. To cite this article:
Covani U, Ricci M, Bozzolo G, Mangano F, Zini A, Barone A. Analysis of the pattern of the alveolar ridge remodelling following single tooth extraction.
Clin. Oral Impl. Res. 22 , 2011; 820–825
doi: 10.1111/j.1600‐0501.2010.02060.x     

Effect of socket preservation therapies following tooth extraction in non-molar regions in humans: a systematic review

Objective: To assess, based on the existing literature, the benefit of socket preservation therapies in patients with a tooth extraction in the anterior or premolar region as compared with no additional treatment with respect to bone level. Material and methods: MEDLINE‐PubMed and the Cochrane Central Register of controlled trials (CENTRAL) were searched till June 2010 for appropriate studies, which reported data concerning the dimensional changes in alveolar height and width after tooth extraction with or without additional treatment like bonefillers, collagen, growth factors or membranes. Results: Independent screening of the titles and abstracts of 1918 MEDLINE‐PubMed and 163 Cochrane papers resulted in nine publications that met the eligibility criteria. In natural healing after extraction, a reduction in width ranging between 2.6 and 4.6 mm and in height between 0.4 and 3.9 mm was observed. With respect to socket preservation, the freeze‐dried bone allograft group performed best with a gain in height, however, concurrent with a loss in width of 1.2 mm. Conclusion: Data concerning socket preservation therapies in humans are scarce, which does not allow any firm conclusions. Socket preservation may aid in reducing the bone dimensional changes following tooth extraction. However, they do not prevent bone resorption because, depending on the technique, on the basis of the included papers one may still expect a loss in width and in height. To cite this article:
Ten Heggeler JMAG, Slot DE, Van der Weijden GA. Effect of socket preservation therapies following tooth extraction in non‐molar regions in humans: a systematic review.
Clin. Oral Impl. Res. 22 , 2011; 779–788
doi: 10.1111/j.1600‐0501.2010.02064.x.
     

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提要：拔牙的微创技术开启了拔牙的新时代,使拔牙这一古老的手术更加走向标准化、微创化、舒适化和个性化。目前,微创拔牙的理念和技术在国内的应用和推广亟待提高。本文对微创拔牙的发展、微创拔牙器械的进步、微创拔牙技术的应用等做一述评,为进一步在国内推广微创拔牙的理念和应用微创拔牙的技术抛砖引玉。     

口服抗凝药物老年患者拔牙术中的临床治疗体会

目的:总结在服用抗凝药物的老年患者拔牙术中的治疗经验。方法:选择2018年1月~2019年6月口腔科就诊的46例(服用阿司匹林患者28例,波立维11例,法华林7例)长期口服抗凝药物且需要拔牙老年患者,拔牙前行凝血酶原时间和国际标准化率检测,分别在术后30分钟、1和24小时对治疗结果进行观察和分析。结果:拔牙术后30分钟出血15例,术后1小时内出血4例,术后24小时复诊出血1例。结论:INR在1.5~2.5范围,拔牙创局部止血处理,且压迫观察1小时,有效地预防抗凝治疗的老年患者在不停用抗凝药的情况下拔牙术后出血的情况。     

拔牙区骨改建对牙齿移动影响的组织学及组织形态测量学研究

目的 :探讨不同愈合阶段的拔牙区内骨密度及骨质结构对牙齿移动的影响 ,以及邻牙向不同愈合阶段的拔牙区内移动时的组织学变化 ,确定邻牙向拔牙区移动的最佳时机。方法 :选择同源 13周龄雄性、SPF级SD大鼠 3 0只 ,分成 3个实验组。3组动物均拔除上颌第一磨牙 ,分别在拔牙后 1、7、2 1d戴用统一规格的矫治器牵第二磨牙向拔牙区移动。所有大鼠在实验结束处死后 ,将上颌骨解剖制备硬组织切片和组织学切片。通过大体标本及组织学观察、组织形态测量等手段 ,研究拔牙区骨改建对牙齿移动的影响。结果 :随着拔牙后间隔时间延长 ,拔牙区骨密度逐渐增加 ,骨结构日趋致密、牙移动逐渐减少 ;拔牙后立即移动牙齿 ,更容易引起根尖牙周组织损害及牙根吸收。结论 :拔牙后应早期移动牙齿 ,其理想的移动时机为拔牙后 1周左右。     

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     

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牙拔除术是口腔颌面外科最常用、最基本的手术,不良的操作方法会造成软、硬组织的创伤,并影响拔牙创的愈合及今后义齿的修复,标准化和规范化的拔牙方法不但可减少拔牙时间和创伤,而且可降低拔牙风险和并发症的发生。     

Effects of lithium on extraction socket healing in rats assessed with micro-computed tomography

Abstract

Objective. Lithium is an activator of β-catenin signaling and β-catenin plays an important role in regulating bone formation and remodeling. The purpose of this study was to investigate the effects of lithium on bone repair in tooth extraction sockets in rats. Material and methods. Twenty male Wistar rats were subjected to maxillary left second molar extraction. The animals received a daily injection of lithium chloride (LiCl) or the same dose of sodium chloride (NaCl) starting 7 days before tooth extraction until sacrifice 14 days after extraction. Rats were randomly divided into: (1) a pre-treated group that received LiCl injection from 7 days before to 3 days after tooth extraction; (2) a post-treated group that received LiCl injection starting 4 days after tooth extraction; (3) a continuously treated group that received LiCl injection for the entire 21 days; and (4) a control group that received NaCl injection only. The volume of new bone and the bone density in the extraction socket were quantified by micro-computed tomography. Results. The percentage of new bone formation in the extraction socket was as follows: 63.2 ± 13.4% (pre-treated group), 53.9 ± 9.8% (post-treated), 23.8 ± 8.0% (continuously treated) and 37.5 ± 4.2% (control). The difference in percentage was statistically significant between each pair of groups. Pre- and post-treated groups also showed a significant increase in the density of new bone. Conclusions. Lithium enhances bone repair in extraction sockets when delivered before or after tooth extraction. Tooth extraction during lithium treatment may impair bone healing.     

Effects of antiresorptive medications on tooth root formation and tooth eruption in paediatric patients

Tooth eruption is a pivotal milestone for children's growth and development. This process involves with the formation of the tooth root, the periodontal ligament (PDL) and the alveolar bone, as the tooth crown penetrates the bone and gingiva to enter the oral cavity. This review aims to outline current knowledge of the adverse dental effects of antiresorptive medications. Recently, paediatric indications for antiresorptive medications, such as bisphosphonates (BPs), have emerged, and these agents are increasingly used in children and adolescents to cure pathological bone resorption associated with bone diseases and cancers. Since tooth eruption is accompanied by osteoclastic bone resorption, it is expected that the administration of antiresorptive medications during this period affects tooth development. Indeed, several articles studying human patient cohorts and animal models report the dental defects associated with the use of these antiresorptive medications. This review shows the summary of the possible factors related to tooth eruption and introduces the future research direction to understand the mechanisms underlying the dental defects caused by antiresorptive medications.     

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提要：牙拔除术是口腔外科最基本的手术操作,但由于牙齿及其周围组织结构在解剖、生理、病理等多方面存在复杂的个体差异性,并且口腔内操作时视野和器械掌控都受到限制,牙拔除术可能产生多种术中、术后并发症,如果对其操作风险掉以轻心,或者缺乏足够的处理能力,这些并发症可能给患者造成较大痛苦甚至危险。因此,充分了解各种拔牙并发症及其预防和处理方法是非常重要的。     

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牙拔除术是口腔颌面外科门诊最常见、最基本的临床治疗操作。由于口腔颌面部解剖及临床操作的特殊性,在拔牙操作中易发生一些临床并发症。本文针对牙拔除术的基本特点、常见失误、并发症类型以及牙拔除术的基本原则进行了阐述,以期为临床上预防拔牙并发症的发生提供参考。     

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目的比较微创拔牙技术与传统凿骨劈冠法拔除下颌低位埋伏阻生智齿的临床疗效。方法选择2012年8月至2013年10月河南省濮阳市油田总医院口腔颌面外科门诊300例下颌低位埋伏阻生智齿患者,按就诊顺序分为微创组与锤凿组各150例。微创组采用微创拔牙器械及微创拔牙技术拔除下颌低位埋伏阻生智齿;锤凿组采用传统的拔牙器械及凿骨劈冠法拔除下颌低位埋伏阻生智齿。对两组手术时间及术中、术后并发症进行比较观察和统计学分析。结果微创组手术时间[（18．0±6.3）min]比锤凿组[（37．0±8．2）min]显著缩短,差异有统计学意义（P〈0．05）;微创组术后疼痛、肿胀、张口受限、干槽症等并发症发生率明显低于锤凿组,差异有统计学意义（P〈0．05）。结论使用微创拔牙技术拔除下颌低位埋伏阻生智齿,手术时间短,创伤小,可明显减少术后并发症,临床疗效优于传统凿骨劈冠拔除法。     

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拔牙术是口腔外科最常见、最基本的手术,出血是常见的并发症之一。由于口腔有着独有的解剖结构和生理环境,如果医生在拔牙围手术期的问诊、术中操作、术后处理等各个环节未加以重视,可能会引起严重的出血,甚至导致患者的死亡。本文通过介绍局部因素导致拔牙出血的原因及其防治,帮助医生认识到拔牙出血的重要性并能正确处理此类并发症,使其临床手术过程更加规范和具有可预见性。     

浅谈牙拔除术后抗菌药物的使用

牙拔除术是口腔颌面外科门诊最常见的手术。总体来看,其并发症的发生率较低,但由于患者群体基数庞大,因此出现并发症的患者群数量也相对较大,其中以术后局部感染最为常见,危害最大。抗菌药物的使用,是否能够降低局部感染的发生率;抗菌药物广泛使用的利弊,一直存在争议。本文仅对拔牙后是否使用抗菌药物以及抗菌药物使用的时机等问题进行初步探讨。     

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提要：牙拔除术是口腔颌面外科领域最常见、最基本、应用最广泛的治疗性手术,也是口腔科医生必须掌握的一种基本治疗手段。传统的拔牙术,特别是不正规的操作或术前、术中及术后处理不当,易引起局部出血、感染、牙折、患牙被推挤移位,甚至颌骨骨折或颞下颌关节损伤等并发症。我们在学习国外高水平牙科医院的基础上,结合本科室的长期临床实践经验,总结出全新的牙拔除术“四化”理念——“标准化的器械”、“微创化的技术”、“规范化的操作”及“人性化的服务”。本文希望能为广大基层医院口腔外科医务工作者提供帮助,在巩固教科书讲授的基础理论知识基础上,对临床工作中的实际操作技术有进一步形象和准确的认识,能清楚地了解每项操作的潜在风险,更准确地了解自己的诊治能力和范围,提高诊治能力和操作信心。