上颌即刻种植后牙槽骨改建的CBCT分析

目的:分析即刻种植术后可能影响上颌牙槽嵴改建的因素。方法:共80例接受上颌即刻种植的患者,在上颌前牙及前磨牙区拔牙后即刻植入80枚种植体。检查并记录如下数据:1种植体表面距颊侧牙槽嵴外侧骨板的距离;2种植体颊侧水平骨缺损距离;3种植体颊侧垂直缺损距离。并于术后4个月行二期手术时复查上述数据。依据以下3个原则进行分析:颊侧牙槽骨厚度;缺牙位置;是否因牙周病拔牙。结果:当颊侧骨板较厚时,牙槽嵴吸收量较少。前磨牙区域牙槽嵴吸收量较少。结论:颊侧骨板的厚度及缺牙位置均有可能影响术后牙槽嵴的改建。在行即刻种植术时,临床医师必须密切关注种植体颊侧骨板的厚度,水平缺损的宽度等条件。     

CBCT技术研究前牙区骨劈开术种植修复的骨吸收特点

目的:采用CBCT技术分析骨劈开手术后种植体唇侧骨板垂直骨吸收特点及与水平向厚度的关系。方法:选取19例上前牙种植患者,共26个种植牙位,牙槽嵴宽度均在3~5 mm之间,采用骨劈开手术联合引导骨组织再生术(GBR)种植Ankylos种植体,患者种植修复完成时和2年后复诊时均拍摄锥形束CT,观察唇侧骨板吸收特点,并根据统计学分析唇侧垂直骨吸收与牙龈退缩的相关性,及与骨板水平向厚度的相关性。结果:种植体唇侧骨板垂直骨吸收与牙龈的退缩有明显的相关性,与唇侧骨板颈部水平向厚度也有相关性。结论:种植治疗时骨劈开技术能够有效增宽牙槽嵴宽度,种植体颈部唇侧骨板水平向厚度是唇侧骨板垂直骨吸收与牙龈退缩的一个重要影响因素。     

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由于种植体生物相容性的不断改良和完善,目前的牙种植体均能获得理想的可预期的骨结合,在新拔除患牙的牙槽窝内即刻植入种植体已经成为一种常规的术式拔牙后即刻种植可有利于减少外科手术次数,有利于牙槽嵴骨量的保存,降低治疗费用并减少缺牙时间,更易被患者接受.但由其解剖生理因素决定,牙槽嵴在牙缺失后通常要出现唇侧骨板的吸收萎缩,这常导致种植体唇面暴露,出现美学上的问题.即刻种植的同时,在充分理解和使用引导骨再生原理的基础上配合骨增量材料的应用才能获得理想的修复效果,本文就我们的临床体会结合文献进行了分析讨论.     

CBCT研究即刻种植愈合期牙槽骨的改变

目的:利用锥形束CT探讨即刻种植后牙槽骨嵴的改变。方法:本研究选择14例上牙即刻种植患者,共植入Ankylos种植体16枚,患者种植手术完成时(T1)和二期手术时(T2)均拍摄锥形束CT(CBCT),测量所有种植体唇颊侧,腭侧,近中,远中四个方向牙槽嵴顶端高度与种植体下端之间的垂直距离。并使用SPSS11.0软件进行配对t检验分析T1-T2期间种植体各方向牙槽骨的吸收变化。结果:T1-T2期间所有种植体唇颊侧,腭侧,近中,远中四个方面牙槽嵴顶端骨高度均发生了明显变化。但吸收情况不尽相同。结论:即刻种植愈合期各方向牙槽骨嵴均发生了明显的骨吸收,唇颊侧骨吸收较其它方向更加明显。     

种植相关的牙槽嵴保存技术

充足的牙槽骨宽高度和骨质量是种植体植入的前提条件。但拔牙后局部牙槽骨的改建和吸收极易造成骨量和骨质减少,影响种植体植入。牙槽嵴保存技术有利于拔牙后牙槽骨的愈合,减少骨吸收,为后期种植修复创造条件。本文将对近年来牙槽嵴保存的方法、疗效及后期种植体植入效果做一综述。     

珊瑚骨粉、口腔修复膜应用于即刻种植的临床研究

目的:选择合适的适应征进行微创拔牙后行即刻种植术,观察人工珊瑚颗粒、海奥生物膜行GBR技术,应用于前牙区即刻种植成骨效果.方法:25例前牙冠根折伴骨吸收患者进行即刻种植手术.微创拔除残根,牙槽窝嵴周少量骨缺损或伴唇侧骨壁洞穿,常规预备后植入种植体,种植体与牙槽窝骨壁间隙内、骨缺损处植入人工珊瑚颗粒(天博骨粉),盖海奥口腔修复膜,种植体均为潜入式愈合,二期手术后常规修复.观察二期手术及修复后6月或1年植骨区外形及牙龈状况.结果:二期手术时牙槽嵴成骨明显,包绕种植体颈周,二期手术修复后6月或1年牙槽外形均较植骨前丰满,牙龈质地、色泽良好.结论:珊瑚骨粉颗粒联合海奥生物膜应用于即刻种植修复少量骨缺损,成骨效果可靠.     

美学区种植同期应用异种骨行引导骨再生术后愈合期间唇侧骨改建的临床研究

目的: 研究美学区种植同期应用异种骨行引导骨再生（GBR）术后愈合期间的唇侧骨改建。方法: 纳入2015年9月—2016年4月在上海交通大学医学院附属第九人民医院口腔种植科行GBR同期种植体植入的上前牙23例。术前、手术当天及二期手术阶段拍摄锥形束CT（CBCT）,记录牙龈厚度（>2 mm或≤2 mm）、骨质分类及使用的屏障膜。利用iCAT Vision数字化软件对种植体颈部肩台下2 mm（C）、体部中点（M）及根尖处（A）唇侧骨板进行测量,测量线与种植体长轴垂直。将纵切线向近中及远中各移动1 mm,得到新的纵切面,以同样方法测量唇侧骨板厚度并记录数值。在术前CBCT上测量牙槽嵴形态特征,记录牙槽嵴高度、倒凹深度及牙槽嵴宽度。采用SPSS 21.0软件包对数据进行统计学分析。结果: 种植体肩台下2 mm、体部中点及根尖处的平均骨吸收值分别为（0.70±0.59）mm、（0.85±0.72）mm和（0.55±0.51）mm,吸收率分别为23.07%、18.53%和12.97%。与植骨吸收相关的自变量中,相关分析表明,倒凹深度和年龄与植骨吸收量显著相关（P<0.05）;将所有变量纳入多重线性回归并行逐步回归分析,仍具有统计学意义的变量为倒凹深度（P<0.05）。结论: 美学区种植同期应用异种骨行GBR术后愈合期间唇侧会有一定程度的骨吸收。患者年龄及牙槽嵴倒凹对GBR术后愈合期内种植体唇侧骨板的改建具有一定影响。牙槽嵴倒凹越大,GBR术后愈合期内唇侧骨板吸收越少。     

美学区种植同期应用异种骨行引导骨再生术后愈合期间唇侧骨改建的临床研究

目的: 研究美学区种植同期应用异种骨行引导骨再生（GBR）术后愈合期间的唇侧骨改建。方法: 纳入2015年9月—2016年4月在上海交通大学医学院附属第九人民医院口腔种植科行GBR同期种植体植入的上前牙23例。术前、手术当天及二期手术阶段拍摄锥形束CT（CBCT）,记录牙龈厚度（>2 mm或≤2 mm）、骨质分类及使用的屏障膜。利用iCAT Vision数字化软件对种植体颈部肩台下2 mm（C）、体部中点（M）及根尖处（A）唇侧骨板进行测量,测量线与种植体长轴垂直。将纵切线向近中及远中各移动1 mm,得到新的纵切面,以同样方法测量唇侧骨板厚度并记录数值。在术前CBCT上测量牙槽嵴形态特征,记录牙槽嵴高度、倒凹深度及牙槽嵴宽度。采用SPSS 21.0软件包对数据进行统计学分析。结果: 种植体肩台下2 mm、体部中点及根尖处的平均骨吸收值分别为（0.70±0.59）mm、（0.85±0.72）mm和（0.55±0.51）mm,吸收率分别为23.07%、18.53%和12.97%。与植骨吸收相关的自变量中,相关分析表明,倒凹深度和年龄与植骨吸收量显著相关（P<0.05）;将所有变量纳入多重线性回归并行逐步回归分析,仍具有统计学意义的变量为倒凹深度（P<0.05）。结论: 美学区种植同期应用异种骨行GBR术后愈合期间唇侧会有一定程度的骨吸收。患者年龄及牙槽嵴倒凹对GBR术后愈合期内种植体唇侧骨板的改建具有一定影响。牙槽嵴倒凹越大,GBR术后愈合期内唇侧骨板吸收越少。     

种植体周围软组织的临床意义和研究进展

种植体周围软组织不仅影响种植体的远期稳定性,同时也对唇颊侧的美观性起着决定性的作用。种植体周围角化龈宽度可以减少菌斑的堆积和局部牙槽嵴的吸收,减少软组织的退缩;具有一定厚度的黏膜同样会对牙槽嵴形成保护,增加种植体周围水平方向和垂直方向的美学评分。目前对种植体周围软组织的研究主要是角化龈宽度的影响,对黏膜厚度的影响研究较少,本文将对种植体周围软组织对种植体的远期稳定性以及红色美学评分的影响作一综述。     

即刻种植术中软硬组织缺损处理方法的研究进展

<正>即刻种植是在牙拔除的同时将种植体立即植入缺牙区的一种种植方式,其优点包括:①避免骨质的过度吸收,更好地保留牙槽嵴的高度及宽度;②新鲜拔牙窝可引导种植体植入到较理想的解剖位置;③减少手术次数,缩短修复时间[1,2]。并且,即刻种植     

Immediate implants at fresh extraction sockets: from myth to reality

In recent years, immediate implant placement has become a common clinical therapeutic protocol representing an alternative to the classical delayed surgical protocol of implant placement. This protocol, however, has not been fully validated, either in terms of fully understanding the influence of implant placement on the socket‐healing process or on the clinical outcomes. This narrative review evaluates the different experimental studies in humans and animals assessing the bone‐healing dynamics of the socket after tooth extraction and the dimensional changes occurring at the socket bone walls. These experimental studies describe, in detail, the hard‐ and soft‐tissue healing of implants placed into fresh extraction sockets, demonstrating that marked morphological changes of the alveolar ridge will occur, independently of the implant installation, thus demonstrating that postextraction bone loss is an inevitable biological process. This evidence has also been corroborated in clinical studies in humans, demonstrating the risk of significant peri‐implant tissue loss, mainly in the areas of high esthetic demand. There is a lack of long‐term evidence on the impact of this protocol on the preservation of the peri‐implant tissues. In conclusion, despite the obvious advantages of this surgical protocol, it also has limitations and is more technically demanding than placing an implant into a healed crest. When selecting this protocol, clinicians should always consider: (a) the gingival biotype of the patient; (b) the thickness and integrity of the socket bony walls; (c) the implant selection as well as the adequate vertical and horizontal position of the implant; and (d) the ideal patient (a nonsmoker with good plaque control).     

Socket healing with and without immediate implant placement

The aim of the present review was to describe the studies produced in Latin America that contributed to the elucidation of the effect of tooth extraction with and without immediate implant installation. An electronic search was conducted in MEDLINE (PubMed), Scopus, Scielo, Lilacs, and Embase to include clinical and experimental (animal) studies on immediate implants. The studies selected had to fulfill the following inclusion criteria: (i) to present clinical and/or histological data on socket healing with or without immediate implant installation; (ii) to be approved by a Latin American Ethic Committee or comparable; and (iii) to include at least one author from a Latin American institution or to be conducted in a Latin America institution. Latin American studies that fulfilled these criteria demonstrated that immediate implant installation was conducive for predictable osseointegration and high survival rates but failed to prevent bone modeling and dimensional reduction of the alveolar ridge. In addition, it was also shown that regenerative approaches, including hard and soft tissue grafts at the time of immediate implant placement, may be beneficial to compensate for the alveolar ridge reduction. Regenerative approaches immediately after tooth extraction may decrease the amount of dimension reduction of the alveolar ridge.     

A prospective, randomized-controlled clinical trial to evaluate bone preservation using implants with different geometry placed into extraction sockets in the maxilla

Aim: The primary objective of this study was to determine the association between the size of the void established by using two different implant configurations and the amount of buccal/palatal bone loss that occurred during 16 weeks of healing following their installation into extraction sockets.
Material and methods: The clinical trial was designed as a prospective, randomized-controlled parallel-group multicenter study. Adults in need of one or more implants replacing teeth to be removed in the maxilla within the region 15–25 were recruited. Following tooth extraction, the site was randomly allocated to receive either a cylindrical (group A) or a tapered implant (group B). After implant installation, a series of measurements were made to determine the dimension of the ridge and the void between the implant and the extraction socket. These measurements were repeated at the re-entry procedure after 16 weeks.
Results: The study demonstrated that the removal of single teeth and the immediate placement of an implant resulted in marked alterations of the dimension of the buccal ridge (43% and 30%) and the horizontal (80–63%) as well as the vertical (69–65%) gap between the implant and the bone walls. Although the dimensional changes were not significantly different between the two-implant configurations, both the horizontal and the vertical gap changes were greater in group A than in group B.
Conclusions: Implant placement into extraction sockets will result in significant bone reduction of the alveolar ridge.
To cite this article:
Sanz M, Cecchinato D, Ferrus J, Pjetursson EB, Lang NP, Jan L. A prospective, randomized-controlled clinical trial to evaluate bone preservation using implants with different geometry placed into extraction sockets in the maxilla.
Clin. Oral Impl. Res . 21 , 2009; 13–21.     

Dimensional ridge alterations following immediate implant placement in molar extraction sites: a six-month prospective cohort study with surgical re-entry

Aim: To assess dimensional ridge alterations following immediate implant placement in molar extraction sites.
Material and methods: Twelve subjects received 12 immediate transmucosal implants in molar extraction sites. Peri-implant defects were treated according to the principles of Guided Bone Regeneration by means of a deproteinized bone substitute and a bioresorbable collagen membrane. Changes in vertical (IS-BD, CREST-BD) and horizontal distances (EC-I, IC-I) of alveolar bony walls to the bottom of the defects (BD) and to the implant surfaces (I) were compared between implant placement and surgical re-entry at 6 months.
Results: The implant survival rate at 6 months was 100%. Statistically significant differences ( P <0.01) were observed in the mean changes in vertical distances IS-BD and CREST-BD between baseline and re-entry. At re-entry, all peri-implant marginal defects assessed from the internal socket wall to the implant surface (IC-I) were healed. The residual combined thickness of the buccal wall with the newly formed peri-implant bone at sites with an initial thickness of 1 mm was statistically significantly smaller ( P <0.05) compared with that of sites with an initial buccal thickness of 2 mm (2.50 ± 0.76 vs. 4±0 mm).
Conclusions: The marginal defects around immediate implants placed in molar extraction sites were completely filled after 6 months of healing through de novo bone formation. Bone resorption was observed from the external aspects of the buccal and oral socket walls. Dimensional changes of the external socket walls were mostly pronounced at the buccal aspects.     

From an immediate implant placement in the post-extraction phase towards immediate loading application: current status

The fresh extraction socket site in the immediate post-extraction phase possesses unique characteristic wound healing cascade. Marked horizontal and vertical resorption of the edentulous ridge occurred shortly following tooth extraction. In periodontally involved teeth, when partial/full socket wall destruction is evident, the ingrowth of connective tissue into the extraction site is unavoidable leading to a deficient ridge. The use of bone substitute materials aiming to preserve the alveolar ridge by stabilizing the blood clot, thus maintaining the volume of the site and at the same time serves as an osteoconductive scaffold which facilitates continual bone formation. immediate Implant placement, is also a reliable, predictable, and successful procedure. Comparative studies regarding immediate implant placement vs. delayed placement (healed sites) reported similar high survival rate for both procedures. The addition of nonfunctional immediate provisionalization (clearance of all contacts in centric occlusion and during eccentric movements to avoid full functional loading of the implant during healing) achieving an instant aesthetic solution, has been shown to have predictable results. However, a meticulous surgical protocol should be followed. In recent years, an immediate functional loading of cross-arch splinted implants proved to be a reliable and successful approach. Moreover evidence-based data comparing immediate, early and delayed loading failed to show significant difference between those treatment modalities. Apparently, primary stability of implants is an important factor in achieving predictable success. It seems that the addition of controlled loading did not impair those results. A systematic review of the current literature related to this procedure showed a survival rate of over 95% in 34 prospective/retrospective studies. Since clinical parameters were proved to be equal whether implants were placed immediate post-extraction or delayed in a healed alveolar ridge, it appears that cross-arch immediate loading of implants placed in extraction and/or healed edentulous ridges is a predictable procedure with long term stability of the results.     

Factors influencing ridge alterations following immediate implant placement into extraction sockets

Aim: To identify factors that may influence ridge alterations occurring at the buccal aspect of the extraction site following immediate implant placement.
Material and methods: In 93 subjects, single-tooth implants were placed immediately into extraction sockets in the maxilla (tooth locations 15–25). A series of measurements describing the extraction site were made immediately after implant installation and at re-entry, 16 weeks later. The implant sites were stratified according to four factors: (i) implant location (anterior/posterior), (ii) cause of tooth extraction (periodontitis/non-periodontitis), (iii) thickness of the buccal bone walls (≤1/>1 mm) and (iv) the dimension of the horizontal buccal gap (≤1/>1 mm).
Results: (i) The location where the implant was placed (anterior/posterior) as well as (ii) the thickness of the buccal bone crest and (iii) the size of the horizontal buccal gap significantly influenced the amount of hard tissue alteration that occurred during a 4-month period of healing. At implant sites in the premolar segment, the fill of the horizontal gap was more pronounced than in the incisor–canine segment, while the vertical crest reduction was significantly smaller. Furthermore, at sites where the buccal bone wall was thick (>1 mm) and where the horizontal gap was large (>1 mm), the degree of gap fill was substantial.
Conclusions: The thickness of the buccal bone wall as well as the dimension of the horizontal gap influenced the hard tissue alterations that occur following immediate implant placement into extraction sockets.
To cite this article:
Ferrus J, Cecchinato D, Pjetursson EB, Lang NP, Sanz M, Lindhe J. Factors influencing ridge alterations following immediate implant placement into extraction sockets.
Clin. Oral Impl. Res . 21 , 2009; 22–29.     

A randomized clinical trial to evaluate and compare implants placed in augmented versus non-augmented extraction sockets: 3-year results

Background: The alveolar ridge undergoes reabsorption and atrophy subsequent to tooth removal and thus exhibits a wide range of dimensional changes. Preservation of the alveolar crest after tooth extraction is essential to enhance the surgical site before implant fixture placement. The aim of this randomized clinical study is to investigate and compare the need for additional augmentation procedures at implant insertion, as well as the success rate and marginal bone loss for implants placed in the grafted sites versus those placed in naturally healed sites. Methods: Forty patients with ≥1 hopeless tooth were randomly allocated to: 1) a test group, receiving extraction and grafting corticocancellous porcine bone; and 2) a control group, receiving extraction without any graft. After 7 months of healing, implants were inserted in each of the sites. The implants were submerged and loaded after 4 months with metal–ceramic rehabilitation. The follow‐up included evaluation of implant diameter and length, the need for additional augmentation procedures at implant placement, implant failure, and marginal bone level changes. All patients were followed over a 3‐year period. Results: One implant failed in the control group at the second stage of surgery (6 months after placement); one implant failed in the test group after 2 years of loading. The cumulative implant success rate at the 3‐year follow‐up visit reached 95% for both groups. No statistically significant differences were detected for marginal bone changes between the two groups. Conclusions: It was concluded that implants placed into grafted extraction sockets exhibited a clinical performance similar to implants placed into non‐grafted sites in terms of implant survival and marginal bone loss. However, grafted sites allowed placement of larger implants and required less augmentation procedures at implant placement when compared to naturally healed sites.     

Bucco-lingual bone remodeling around implants placed into immediate extraction sockets: a case series

BACKGROUND: Implants placed immediately after tooth extraction have shown high percentages of clinical success. Few studies in the scientific literature have observed the horizontal bone remodeling in the buccal-lingual direction after immediate placement of implants. The aim of this study was to analyze bone healing and coronal bone remodeling around 15 implants placed immediately after tooth removal without the use of guided bone regeneration (GBR) techniques. METHODS: Ten patients received a total of 15 implants placed immediately after removal of 15 single-rooted teeth. All implants were placed within the alveolar confines, limiting, in most cases, small peri-implant bone defects. After implant placement, the distance from the buccal to lingual bone plate was measured. No membranes or filling materials were used. Primary flap closure was performed in all cases. RESULTS: At second-stage surgery, all peri-implant defects were completely filled and the distance from buccal to lingual bone was measured again. The pattern of bone healing around the neck of immediate implants showed an absence of peri-implant defects and a narrowing of bone crest width in a buccal-lingual direction. The mean distance between buccal bone and lingual bone at the time of implant placement was 10.5 mm (+/- 1.52) and, at second-stage surgery, 6.8 mm (+/- 1.33). CONCLUSIONS: The coronal bone remodeling around immediate implants showed a healing pattern with new bone apposition around the neck of the implants and, at the same time, bone resorption with horizontal width reduction of the bone ridge. The small peri-implant bone defects were completely healed without the use of GBR procedures. An absence of complications during the healing period was also observed, probably due to the absence of barrier membranes and grafting materials.     

Dental cone beam computed tomography analyses of postoperative labial bone thickness in maxillary anterior implants: comparing immediate and delayed implant placement

This study aimed to evaluate the influence of labial alveolar bone thickness and the corresponding vertical bone loss on postoperative gingival recessions around anterior maxillary dental implants. Using cone beam computed tomography (CBCT) scanning, the temporal changes of three-dimensional images of alveolar bone were monitored to determine hard and soft tissue outcomes of two different implant placement techniques: delayed two-stage and immediate placement. Furthermore, for the delayed two-stage placement, guided bone regeneration was applied using either nonresorbable or resorbable membranes combined with anorganic bovine bone matrix. The comparative results suggested that gingival recessions were significantly lower in delayed two-stage placement, especially when using a nonresorbable membrane, compared to immediate placement, and labial bone thickness, measured by CBCT, offered an effectual indicator to assess gingival recession in the anterior region.     

For which clinical indications in dental implantology is the use of bone substitute materials scientifically substantiated?

Purpose: The objective of this systematic review was to provide a basis for an expert consensus group to evaluate the influence of different particulate bone substitute materials in local bone augmentation procedures in conjunction with dental implant placement on implant survival and histology. Materials and methods: The following indications were analysed with either simultaneous or delayed dental implant placement: external or internal maxillary sinus floor elevation and vertical and/or lateral alveolar ridge augmentation. Retro- and prospective studies written in English or German including 20 or more patients (for randomised, controlled trials and prospective, split-mouth trials with 5 or more patients) were eligible for this review. The review focused on (1) performance of the augmentation procedures (total augmentation loss, gain of vertical and horizontal alveolar ridge dimensions, histomorphometric data of the augmented areas) and (2) dental implant success criteria (survival rates of the inserted dental implants, peri-implant bone levels under functional loading). Results: From over 3800 abstracts identified, 72 full-text articles fulfilled the inclusion criteria and were further evaluated (52 studies on maxillary sinus floor elevation procedures and 21 studies on vertical and/or lateral alveolar ridge augmentation). The majority of the included studies were prospective studies including a rather limited number of patients and short observation periods. Conclusions: There is a high level of evidence that survival rates of dental implants placed into augmented areas are comparable with survival rates of implants placed into pristine bone. For maxillary sinus floor elevation, all investigated bone substitute materials performed equally well compared with bone, with high dental implant survival rates and adequate histomorphometric data. For the alveolar ridge augmentation procedures, the heterogeneity of the available data did not allow identification of a superior grafting technique.