富血小板血浆对珊瑚支架上骨髓基质细胞增殖和成骨分化的影响

目的：评价富血小板血浆（plateletrichplasma，PRP）对珊瑚支架上骨髓基质细胞（marrowstromalcells，MSCs）增殖和成骨分化的影响。方法：将体外培养、扩增和诱导的兔MSCs悬液与同一供体来源的PRP混合，滴加到珊瑚圆片上，再滴加牛凝血酶溶液，形成珊瑚／MSCs／PRP复合物，继续在体外培养。以珊瑚／MSCs复合物和珊瑚／PRP复合物作对照。8d和14d，通过MTT法检测MSCs增殖情况；通过组织化学方法检测培养液中碱性磷酸酶活性和骨钙素含量；通过扫描电镜观察MSCs在珊瑚支架上附着、生长和增殖情况。结果：珊瑚／MSCs／PRP组的光密度值明显大于珊瑚／MSCs组（P〈0．05）；珊瑚／MSCs／PRP组培养液中的ALP活性和OC含量明显大于珊瑚／MSCs组（P〈0．05）；扫描电镜显示：珊瑚／MSCs／PRP组，大量MSCs附着于珊瑚表面和孔洞壁，可见孔洞内有血小板和纤维网格样结构存在；珊瑚／MSCs组，珊瑚表面和孔洞壁有少量MSCs附着；珊瑚／PRP组，珊瑚表面及其孔洞内有大量的血小板和纤维网格样结构存在。结论：PRP促进了珊瑚支架上MSCs的增殖、成骨分化和粘附。     

位点保存术在口腔种植中的研究进展

良好的牙槽骨形态和充足的骨量对种植成功具有重要意义,部分患者因拔牙前已存在中重度的牙槽骨缺损,在牙槽窝愈合后牙槽骨不能达到理想的高度及宽度,使种植难度增加。位点保存作为临床常用的骨量保存方法,可有效减少牙槽骨吸收,维持软组织轮廓,本文就位点保存术在口腔种植中的研究进展作一综述。     

浓缩生长因子复合人工骨材料的磨牙位点保存效果评价

 目的　评价浓缩生长因子（concentrated growth factor，CGF）复合人工骨材料+双层CGF膜应用于磨牙位点保存术的临床效果。方法　选取2018—2019年于辽宁省人民医院口腔科行磨牙拔除术并需要种植修复的患者24例，随机分为研究组和对照组，每组各12例。研究组采用微创牙拔除术和CGF复合人工骨材料+双层CGF膜位点保存术；对照组采用微创牙拔除术和人工骨材料+胶原膜位点保存术。分别于术前和术后3个月拍摄根尖片和锥形束CT（CBCT），比较两组牙槽骨高度和宽度的变化。结果　（1）应用根尖片测量发现，研究组近中牙槽骨高度降低量远小于对照组，差异有统计学意义（t = 2.91，P < 0.05）；而两组远中牙槽骨高度降低量比较，差异无统计学意义（t = 0.69，P > 0.05）。（2）应用CBCT测量发现，研究组颊舌向牙槽骨宽度减少量［（1.68 ± 0.40）mm］小于对照组［（2.32 ± 0.83）mm］，差异有统计学意义（t = 2.34，P < 0.05）；研究组近中颊侧和中央舌侧牙槽骨高度降低量小于对照组，差异有统计学意义（t值分别为2.43、3.02，均P < 0.05）；其他位点牙槽骨高度降低量组间比较，差异无统计学意义（均P > 0.05）。结论　将CGF复合人工骨材料+双层CGF膜应用于磨牙位点保存术，能有效减少牙槽骨的吸收，为种植修复提供良好的基础条件。     

应用锥形束CT对种植区牙槽骨质量分类方法的改良研究

目的    应用锥形束CT（cone beam CT，CBCT）测量种植区牙槽骨质量并结合Lekholm和Zarb分类法对骨质量分类方法进行改良，以期为提高牙槽骨质量分类的准确性提供指导。方法    选择2015年10月至2017年10月在呼和浩特市口腔医院种植科进行种植修复的196例患者术前CBCT影像资料，应用 Invivo5诊断设计软件测量306个种植位点的牙槽骨皮质骨厚度和松质骨密度（皮质骨与松质骨的CT值差值），以Lekholm和Zarb分类法为基础结合测量数据对骨质量进行改良后的量化分类。结果    牙槽骨皮质骨厚度为0.18 ~ 2.89 mm，中位数为0.92 mm。皮质骨与松质骨的CT值差值为88.5 ~ 667.8 HU，应用百分位数法找到33.3%和66.6%对应的数值分别为297.8 HU和356.1 HU。依据此数据结合Lekholm和Zarb分类法将196例患者的306个种植位点骨质量分为4类，其中Ⅰ类骨种植位点46个（占15.0%），Ⅱ类骨104个（占34.0%），Ⅲ类骨114个（占37.3%），Ⅳ类骨42个（占13.7%）。结论    结合Lekholm和Zarb分类法，应用CBCT测量种植区牙槽骨质量并进行分类方法的改良，可为临床医生术前评估牙槽骨质量提供一定参考。     

浓缩生长因子复合人工骨材料的磨牙位点保存效果评价

目的　评价浓缩生长因子（concentrated growth factor,CGF）复合人工骨材料+双层CGF膜应用于磨牙位点保存术的临床效果。方法　选取2018—2019年于辽宁省人民医院口腔科行磨牙拔除术并需要种植修复的患者24例,随机分为研究组和对照组,每组各12例。研究组采用微创牙拔除术和CGF复合人工骨材料+双层CGF膜位点保存术;对照组采用微创牙拔除术和人工骨材料+胶原膜位点保存术。分别于术前和术后3个月拍摄根尖片和锥形束CT（CBCT）,比较两组牙槽骨高度和宽度的变化。结果　（1）应用根尖片测量发现,研究组近中牙槽骨高度降低量远小于对照组,差异有统计学意义（t = 2.91,P < 0.05）;而两组远中牙槽骨高度降低量比较,差异无统计学意义（t = 0.69,P > 0.05）。（2）应用CBCT测量发现,研究组颊舌向牙槽骨宽度减少量［（1.68 ± 0.40）mm］小于对照组［（2.32 ± 0.83）mm］,差异有统计学意义（t = 2.34,P < 0.05）;研究组近中颊侧和中央舌侧牙槽骨高度降低量小于对照组,差异有统计学意义（t值分别为2.43、3.02,均P < 0.05）;其他位点牙槽骨高度降低量组间比较,差异无统计学意义（均P > 0.05）。结论　将CGF复合人工骨材料+双层CGF膜应用于磨牙位点保存术,能有效减少牙槽骨的吸收,为种植修复提供良好的基础条件。     

骨髓间充质干细胞结合珊瑚人工骨移植修复牙周缺损的实验研究

目的评估自体骨髓间充质干细胞（MSCs）种植珊瑚人工骨（NC）后形成的复合物结合牙周引导组织再生术治疗狗牙周缺损的效果。方法（1）体外分离获得狗的MSCs，矿化培养液进行成骨诱导，检测细胞的成骨活性；（2）将NC和PLGA—NC复合膜分别吸附MSCs共培养，观察复合物的形态：（3）将MSCs与NC共培养10d后的复合物移植到狗的牙周实验性骨缺损处。8周后行组织学染色牙周再生检测。结果（1）诱导后的MSCs成骨活性明显，矿化结节茜素红染色和Ⅰ型胶原免疫组化染色阳性；（2）MSCs与NC和PLGA—NC复合膜均有较好的生物相容性；（3）MSCs—NC复合物移植后可修复牙周缺损。结论MSCs有望成为牙周前体细胞的体外来源，骨组织工程学方法修复牙周缺损是可行的。     

富血小板血浆对珊瑚支架上骨髓基质细胞异位成骨的影响

目的：评价富血小板血浆（platelet rich plasma,PRP）对珊瑚支架上骨髓基质细胞（marrow stromal cells,MSCs）异位成骨的影响。方法：将MSCs悬液与同一供体来源的PRP混合后滴加到珊瑚圆片上,形成珊瑚/MSCs/PRP复合物。以同样数量MSCs或PRP制备珊瑚/MSCs和珊瑚/PRP复合物。将3种复合物植入同一裸鼠的背部皮下。术后4周和8周取材,通过组织学观察和组织形态测量分析评价其异位成骨情况。结果：植入后4周或8周,珊瑚/MSCs/PRP组珊瑚表面及其孔洞内有大量的软骨或骨质形成;珊瑚/MSCs组珊瑚表面及其孔洞内也有软骨或骨质形成,并有纤维结缔组织长入;珊瑚/MSCs/PRP组形成的软骨或骨质的量明显多于珊瑚/MSCs组（P〈0.01）;珊瑚/PRP组珊瑚周围及其孔洞内有大量纤维组织,未见骨或软骨形成。结论：PRP促进了珊瑚支架上MSCs的异位成骨。     

口腔内局部因素对于牙槽骨吸收的影响

牙槽骨是高度可塑性组织，人体骨骼中代谢最活跃的部分。牙槽骨具有受压力侧吸收，受牵引力会增生的特性，改建符合Wolff定律。牙槽骨是全身骨骼的一部分．影响骨代谢的全身因素如维生素D缺乏、中年妇女雌激素水平下降、与骨代谢有密切关系的神经肽（如神经肽Y、β-内啡肽，一氧化氮等）、还有影响钙磷代谢的一些疾病均会对牙槽骨产生一定影响。     

富血小板血浆对人脂肪间充质干细胞增殖及成骨分化能力的影响

目的：探讨富血小板血浆（PRP）对人脂肪间充质干细胞（hADSCs）增殖、分化及成骨能力的影响。方法：脂肪组织体外分离获得hADSCs,2次离心制备PRP,氯化钙加人凝血酶激活PRP。倒置相差显微镜观察成骨诱导实验中PRP对细胞增殖、分化状况的影响,钙-钴法检测PRP作用下hADSCs矿化结节形成,碱性磷酸酶（ALP）检测PRP对细胞活性及分化能力的影响。CCK-8法检测成骨诱导组和非成骨诱导组加PRP培养后2、4、6、8、16d细胞活性变化。结果：成骨诱导实验中50%PRP30μL组细胞密集、数量最多,且有剂量依赖性;钙-钴法检测见PRP原液组细胞染色最深,且有浓度依赖性;碱性磷酸酶显色见PRP原液组细胞活性最强,染色最深。CCK-8检测显示无论有无成骨诱导,各浓度PRP均可促进细胞增殖,且有浓度依赖性。结论：适宜浓度的PRP可明显促进hADSCs增殖,并有浓度及剂量依赖性。     

富血小板血浆与种植体骨整合

20世纪60年代Branemark提出了“骨整合”理论（osseointegrafion theory），从而翻开了骨整合理论研究和现代种植学发展的新篇章。几十年来，口腔种植研究者们为了缩短种植体骨整合时间以解除缺牙患者的痛苦，努力探索促进骨整合的因素。近年来，随着富血小板血浆（platelet-richplasma，PRP）在软组织及骨科领域的应用日益成熟，国外有学者尝试把PRP应用于种植体的骨整合并取得初步成果。作者就该领域的理论研究、实验及临床应用作一综述。     

Alveolar ridge preservation prior to implant placement with surgical-grade calcium sulfate and platelet-rich plasma: a pilot study in a canine model

PURPOSE: To evaluate the combination of surgical-grade calcium sulfate (SGCS) and platelet-rich plasma (PRP) for alveolar ridge preservation prior to implant placement. MATERIALS AND METHODS: Five mongrel dogs were used as subjects. Four enlarged mandibular extraction sockets, 2 on each side, were created in each dog. According to a split-mouth design, the 2 anterior sockets received either SGCS/PRP (SGCS/PRPant) or were left unfilled, while the 2 posterior sockets received either SGCS/PRP (SGCS/PRPpost) or SGCS. Computerized tomographic (CT) scans were conducted at 1 day and 8 weeks postextraction to detect the change in ridge height. Bone scintigraphy was performed at 2, 4, and 6 weeks to investigate new bone formation activity. At 8 weeks, 1 dog was sacrificed for histologic and histomorphometric study. Meanwhile, implants were placed in the remaining 4 dogs. These 4 dogs were sacrificed after 3 months. RESULTS: Less ridge resorption was observed in the anterior SGCS/PRP-filled sites compared to unfilled sites (P = .001), while no significant difference was found between the SGCS/PRPpost and SGCS groups (P = .544). Bone scintigraphy showed that sites filled with SGCS/PRP showed significantly higher count/pixel at 2 (P = .028), 4 (P = .009), and 6 weeks (P = .037) than the unfilled sites. Nevertheless, the SGCS/PRPpost group achieved significantly higher values than the SGSC group only at 2 weeks (P = .036). Histomorphometrically, the SGCS/PRPant group showed a significantly higher percentage of bone-implant contact than the unfilled group (P = .024), but no significant difference was detected between the SGCS/PRPpost and SGCS groups (P = .979). CONCLUSION: Grafting SGCS/PRP in fresh extraction sockets reduced alveolar ridge resorption and promoted the bone formation in this canine model. The addition of PRP to SGCS resulted in the enhancement of bone regeneration in the early phase of healing.     

罹患重度牙周炎上颌磨牙拔除后运用微翻瓣牙槽嵴保存术简化种植治疗复杂性（附1例2年随访报告）

罹患重度牙周炎的患牙常伴有严重的感染和牙槽骨破坏,而且拔牙后牙槽窝在愈合过程中进一步骨吸收和改建,增加了后期以修复为导向的种植治疗难度。在上颌磨牙区因毗邻上颌窦,种植治疗常需要进行上颌窦提升术来弥补垂直骨量不足。文章展示了1例罹患重度牙周炎的上颌磨牙,通过微创拔牙后彻底清除牙槽窝感染,结合微翻瓣牙槽嵴保存术,有效减少牙槽窝愈合过程中的骨吸收,实现牙槽嵴的保存和重建,为后期种植修复提供了良好的硬组织三维条件。这一方法将上颌磨牙区骨增量术前移,简化了后续种植治疗的复杂性,值得临床推广应用。     

Effects of a putty-form hydroxyapatite matrix combined with the synthetic cell-binding peptide P-15 on alveolar ridge preservation

BACKGROUND: Various grafting materials have been used for preservation of the dimensions of the residual alveolar ridge following tooth extraction. The purpose of this study was to evaluate clinical, histomorphometric, and radiographic healing 4 months after tooth extraction with or without placement of a putty-form anorganic bovine-derived hydroxyapatite matrix combined with a synthetic cell-binding peptide P-15 (Putty P15) to determine the effect on alveolar ridge preservation following exodontia. METHODS: Twenty-four consecutive subjects in need of extraction of maxillary premolars were recruited. Recruited subjects were randomly assigned to the test (Putty P15 and bioabsorbable collagen wound dressing material) or control (bioabsorbable collagen wound dressing material only) group. Data were recorded at 1, 2, 4, 8, and 16 weeks after ridge preservation procedures. At 16 weeks, a reentry surgery was performed, clinical measurements were repeated, and bone core biopsies were obtained for histomorphometric analysis prior to dental implant placement. RESULTS: The control group had a mean reduction in ridge height of -0.56 +/- 1.04 mm, whereas alveolar ridge height appeared to remain unchanged in the test group (0.15 +/- 1.76). The test group showed a mean reduction in ridge width of -1.31 +/- 0.96 mm, whereas the mean value for the control group was -1.43 +/- 1.05 mm. No statistical significance was observed between the groups. Mean bone density was significantly superior in the test group (2.08 +/- 0.65 versus 3.33 +/- 0.65). Histomorphometric analyses revealed similar percentages of bone vitality (test: 29.92% +/- 8.46%; control: 36.54% +/- 7.73%). Comparable percentages of bone marrow and fibrous tissue also were observed (test: 65.25% +/- 6.41%; control: 62.67% +/- 7.41%). Only 6.25% of the Putty P15 particles remained at 4 months in the analyzed biopsies. CONCLUSION: A favorable response was observed when Putty P15 was applied to extraction sockets, suggesting that it may be useful for alveolar ridge preservation prior to dental implant placement.     

Histologic comparison of healing after ridge preservation using human demineralized bone matrix putty with one versus two different-sized bone particles

Background: Ridge preservation can minimize the loss of alveolar bone subsequent to tooth extraction in preparation for implant therapy. The purpose of this study is to histologically and clinically compare human demineralized bone matrix (DBM) putty with one size of bone particles (SPS) to human DBM putty with two different sizes of bone particles (multiple particle sizes [MPS]) in ridge preservation after molar extractions. Methods: Molar tooth extraction and ridge preservation were performed in 20 participants for each treatment group. Approximately 20 weeks after grafting, core biopsies were obtained during implant placement and analyzed under light microscopy. Specimens were analyzed for the percentage area of vital bone, residual graft particles, and non‐mineralized structures (connective tissue/other non‐mineralized tissue [CT]). Changes in alveolar ridge dimensions were also determined. Results: Sixteen participants in the SPS group and 14 in the MPS group completed the study. The SPS group had a mean of 49% vital bone, 8% residual graft, and 43% CT. The MPS group had 53%, 5%, and 42%, respectively. Patients in both groups lost a mean of <1 mm alveolar height on the buccal and lingual aspects and <1.5 mm of total ridge width. There were no statistically significant differences between the two groups for any clinical or histologic parameters. Conclusion: The results of this study suggest that addition of larger bone particles to DBM putty does not offer additional benefit in the preservation of alveolar bone after the extraction of molar teeth.     

Effect of Healing Time on New Bone Formation After Tooth Extraction and Ridge Preservation With Demineralized Freeze‐Dried Bone Allograft: A Randomized Controlled Clinical Trial

Background: Clinicians and patients continually search for procedures to decrease time from tooth extraction to restoration. Evidence to date is limited concerning timing of ridge preservation healing and reentry for implant placement. The first objective of this study is to histologically evaluate new bone formation 8 to 10 weeks versus 18 to 20 weeks after extraction of non‐molar teeth and ridge preservation using demineralized freeze‐dried bone allograft (DFDBA). The second objective is to compare dimensional changes including ridge width and height at the two healing time points. Methods: Forty‐four patients had tooth extraction and ridge preservation with DFDBA that was obtained from a single donor. Clinical measurements were made to evaluate ridge height and width. Patients were randomly allocated to short‐term (8 to 10 weeks) and long‐term (18 to 20 weeks) healing groups. Sites were reentered at the appropriate healing time, core biopsy was obtained, and a dental implant was placed. The same ridge dimensions were measured at time of implant placement. Histomorphometric analysis was performed to determine percentage of new vital bone formation, residual graft, and connective tissue (CT)/other. Results: A significantly higher percentage (47.41%) of new vital bone formation was found in the long‐term healing group compared with the short‐term healing group (32.63%) (P = 0.01). There was no significant difference in percentage of residual graft, percentage of CT/other, or ridge dimensional changes. Conclusion: This study indicates significantly greater new vital bone formation occurs after tooth extraction and ridge preservation with DFDBA when sites healed for 18 to 20 weeks compared with 8 to 10 weeks prior to dental implant placement.     

前牙美学区牙槽嵴保存延期种植的临床研究

目的探讨前牙美学区即刻拔牙后采用牙槽嵴保存技术对延期种植的美学修复影响。方法收集选取2016—2018年于南京医科大学附属口腔医院就诊的患者20例,其中男8例、女12例,所有患者美学区无法保留患牙且骨质缺损较严重,需行前牙美学修复,行前牙微创拔牙,拔牙后即刻行植骨术和胶原膜隔离,引导拔牙窝骨再生,实现位点保存。6个月后摄片测量牙槽嵴骨量增量情况,植入种植体,术后3~6个月完成最终上部修复。观察种植修复效果,包括红色美学指数(PES)、牙冠白色美学指数(WES)、牙槽嵴宽度和高度等,应用SPSS 16.0进行描述性统计分析。所有病例随访3年观察修复疗效。结果前牙种植美学修复PES/WES总均值为15.17±3.2,PES的均值为7.53±1.68,WES的均值为7.64±1.52。种植体周围骨垂直吸收速率平均0.45毫米/年以下,修复后达到了满意的美学效果。结论对于骨质缺损较严重的前牙美学区,前牙区拔牙后牙槽嵴保存术实现了良好的骨增量,维持了牙槽嵴宽度和高度,拔牙后牙槽嵴保存术加延期种植是保证种植成功的有效方法。     

Principles and implications of site preservation for alveolar ridge development

The extraction of a tooth normally results in the loss of ridge height and width. Often, clinicians are faced with the management of edentulous sites that are less than optimal for prosthetic rehabilitation and implant restoration due to considerable alveolar ridge collapse after tooth removal. Site preservation using bone grafts or substitutes with and without a membrane maintain ridge dimensions and contours. However, some clinicians believe that such procedures are over-treatment. This paper reviews the concepts and indications for site preservation following tooth extraction for the purpose of facilitating implant placement and conventional prosthetic restoration.     

Alveolar ridge preservation in the esthetic zone

In the esthetic zone, in the case of tooth extraction, the clinician is often confronted with a challenge regarding the optimal decision‐making process for providing a solution using dental implants. This is because, after tooth extraction, alveolar bone loss and structural and compositional changes of the covering soft tissues, as well as morphological alterations, can be expected. Ideally, the therapeutic plan starts before tooth extraction and it offers three options: spontaneous healing of the extraction socket; immediate implant placement; and techniques for preserving the alveolar ridge at the site of tooth removal. The decision‐making process mainly depends on: (i) the chosen time‐point for implant placement and the ability to place a dental implant; (ii) the quality and quantity of soft tissue in the region of the extraction socket; (iii) the remaining height of the buccal bone plate; and (iv) the expected rates of implant survival and success. Based on scientific evidence, three time‐periods for alveolar ridge preservation are described in the literature: (i) soft‐tissue preservation with 6–8 weeks of healing after tooth extraction (for optimization of the soft tissues); (ii) hard‐ and soft‐tissue preservation with 4–6 months of healing after tooth extraction (for optimization of the hard and soft tissues); and (iii) hard‐tissue preservation with > 6 months of healing after tooth extraction (for optimization of the hard tissues).     

Implant treatment of two failing or missing central incisors in the aesthetic region: a treatment protocol and 1-year prospective study

Implant treatment for two central incisors in the maxillary aesthetic region is complex due to concerns regarding inter-implant hard and soft tissue stability. A treatment protocol was therefore developed and implemented in a 1-year prospective case series study involving 16 patients with two failing or missing central incisors in the maxillary aesthetic region. The protocol consists of five options depending on whether teeth are still present (options 1–3) or not (options 4 and 5) and on the amount of bone available at the start of treatment: (1) extraction followed by immediate implant placement and provisionalization, (2) extraction followed by immediate implant placement and delayed provisionalization, (3) extraction followed by ridge preservation, delayed implant placement and immediate provisionalization, (4) delayed implant placement and guided bone regeneration with delayed provisionalization, (5) guided bone regeneration (extensive bone augmentation of the alveolar ridge), delayed implant placement, and delayed provisionalization. The patients were assessed regarding peri-implant hard and soft tissue parameters, aesthetic index score, and patient satisfaction. All treatment options showed good clinical and radiographic results and high patient satisfaction.     

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.