Marginal Bone Loss in Implants Placed in the Maxillary Sinus Grafted With Anorganic Bovine Bone: A Prospective Clinical and Radiographic Study

Background: Sinus elevation is a reliable and often‐used technique. Success of implants placed in such situations, even with bone substitutes alone, prompted the authors of this study to strive for bone loss close to zero and research variables that cause higher or lower rates of resorption. The objective of this study is to evaluate survival rates and marginal bone loss (MBL) around implants placed in sites treated with maxillary sinus augmentation using anorganic bovine bone (ABB), and identify surgical and prosthetic prognostic variables. Methods: Fifty‐five implants were placed in 30 grafted maxillary sinuses in 24 patients. Periapical radiographs were evaluated immediately after implant placement (baseline), 6 months, and at the most recent follow‐up. MBL was calculated from the difference between initial and final measurements, taking into account a distortion rate for each radiograph compared with original implant measurements. Results: Survival rate was 98.2%, with only one implant lost (100% survival rate after loading) over a mean follow‐up time of 2.0 ± 0.9 years. MBL ranged from 0 to 2.85 mm: 75.9% of mesial sites and 83.4% of distal sites showed <1 mm of MBL, whereas 35.2% of mesial sites and 37% of distal sites exhibited no bone loss. MBL was significantly (P <0.05) greater in open‐flap compared with flapless surgery. Conclusions: Within the limitations of the present study, it was concluded that maxillary sinus elevation with 100% ABB gives predictable results, and that flapless surgery results in less MBL compared with traditional open‐flap surgery.     

Maxillary Sinus Augmentation with Autologous and Heterologous Bone Graft: A Clinical and Radiographic Report of Immediate and Delayed Implant Placement

Purpose

The aim of this study was to evaluate cumulative survival rate of implants placed on augmented maxillary sinus using a mixture of autologous bone harvested from the maxillary tuberosity and bovine-derived HA and to assess the height of the grafted material through radiographic evaluation.

Methods

Thirty-five patients were treated with maxillary sinus augmentation and 93 implant fixtures were installed. The height of the augmented sinus and the gain of bone volume were measured by Cone Beam CT Scan and intraoral radiographs immediately after augmentation and up to 48 months subsequently. Changes in the height of the sinus graft material were calculated radiographically.

Results

The cumulative survival rate was 98.92 % in all 93 implants. Additionally, normal healing process without any complication was observed in all patients. The original sinus height was a mean of 4.52 mm (range 2.0–6.4 mm) and the augmented sinus height was a mean of 14.1 mm (range 12.0–16.5 mm) after the surgery. The bone volume gain was a mean 9.613 mm (range 7–13 mm).

Conclusions

Within the limitations of this study, it would appear from the clinical and radiographic results that the sinus lift procedure with autologous bone graft harvested from the maxillary tuberosity combined with deproteinized bovine bone allows for a predictable outcome regarding the amount of bone formation in sinus floor augmentation and the immediate placement of implants, when possible, is recommended.     

牙种植体植入同期植骨增加种植床骨量的临床观察

对３８例牙缺失伴局部骨量不足的患者,在牙种植体植入同期,分别采用羟基磷灰石ＨＡ、ＨＡ加自体骨、脱钙骨和自体骨移植,增加种植床的三维骨量,３７例获得成功,１例失败。结果表明：牙种植体植入同期植骨修复局部骨缺损是可行的,有利于拓我齿修复的适应症和提高长期成功率。ＨＡ,ＨＡ加自体骨、脱钙骨和自体骨均可作为植骨材料,但应根据骨量不足的类型进行选择。     

上颌窦侧壁抬升植骨种植的临床研究

目的:探讨应用上颌窦侧壁抬升植骨方法进行种植的优缺点和近远期效果。方法:2000年1月至2006年12月对28例患者行上颌窦侧壁抬升植骨种植。上颌窦底提升高度6.9mm-14.7mm,平均11.2mm。采用人工骨Bio-Oss或自体血提取的富血小板血浆(platelet-richplasma,PRP)与人工骨Bio-Oss混合填入上颌窦,用可吸收性胶原膜Bio-Gide覆盖。共抬升32侧,植入种植体57枚,均采用固定修复。种植后追踪时间9-62个月,平均28个月。观察方法为临床检查和X线检查,采用Wheeler存留标准评估,纳入Kaplan-Meier存留曲线统计。结果:在随访过程中,一颗植体在植入7个月后松动最终取出,其余植体稳定性良好,使用正常,患者满意,据Wheeler存留标准统计存留率为98.2%。结论:当上颌后牙区牙齿缺失且余留骨量不足时,通过上颌窦侧壁开窗抬升植骨可以有效增加骨高度,满足种植的骨条件,近远期效果理想。     

上颌窦底外提升植骨术49例牙种植的临床分析

目的:观察比较上颌窦底外提升植骨术同期或延期牙种植的临床效果.方法:对2003-04-2009-12在烟台市口腔医院种植中心就诊的49例行上颌窦底外提升植骨术,同期或延期牙种植的患者进行临床效果评价,随访观察时间为1～7年,采用寿命表法及x2检验进行统计学分析.结果:49例患者无1人失访,上颌窦底外提升植骨术同期牙种植...     

Pterygomaxillary Implants: A Graftless Solution to Deficient Maxillary Bone

Edentulism is one of the common dental problems in the aging population. Implant therapy has emerged as one the valid and effective solutions to this problem. However in the maxilla, posterior part presents with several anatomic obstacles in the form of bone quality, quantity, size of maxillary antrum and poor accessibility. There are various options like sinus lift with graft and pterygomaxillary implant options available. Option like ptergomaxillary implants requires lot of skill of technic sensitivity and skill of the surgeon and also is proven to be statistically superior. Case reports of pterygomaxillary implants for both partially edentulous and fully edentulous conditions are hereby described in the article.     

开窗植骨与闭合冲压上颌窦底提升同期种植的临床研究

目的:研究比较上后牙缺失牙槽嵴高度不足患者,根据上颌窦底牙槽嵴骨高度不同,选用开窗植骨或闭合冲压提升上颌窦底,同期种植牙的治疗效果。方法:43例(55侧)上后牙缺失患者,其中34例(40侧)窦底牙槽嵴骨高6~10 mm者行闭合冲压上颌窦底提升术,其余9例(15侧)骨高2~5 mm者行开窗植骨上颌窦底提升手术,均同期完成一期种植体植入手术。结果:所有患者术后未出现上颌窦炎症,9例行开窗植骨上颌窦底提升手术的患者,无窦膜穿孔,平均提升窦底高度5.8 mm,26颗种植体平均负载30个月,种植体稳定,骨结合状况良好。34例行闭合冲压上颌窦底提升术的患者,平均提升窦底高度4.3 mm,手术操作中有3颗发生可察觉窦膜破孔,发生率为4.1%(3/73),在73颗种植体中,有2颗种植体失败,71颗种植体平均负载23个月,种植体稳定,未见明显骨吸收,成功率97.3%(71/73)。结论:闭合冲压上颌窦底提升术是一种微创、简单、可靠用于上颌后牙上颌窦底牙槽嵴骨高度不足的种植临床技术,临床上应根据上颌窦底牙槽嵴骨高度不同,选用开窗植骨或闭合冲压提升上颌窦底。     

Retrospective Evaluation of Crestal Bone Changes Around Implants With Reduced Abutment Diameter Placed Non‐Submerged and at Subcrestal Positions: The Effect of Bone Grafting at Implant Placement

Background: There is limited information regarding the effect of grafting of the osteotomy after subcrestal implant placement. The primary aim of this study is to retrospectively evaluate the effect of bone grafting of the defect between the bone crest and the coronal aspect of implants with reduced abutment diameter placed non‐submerged and at subcrestal positions. Methods: Records of 50 consecutive patients treated with subcrestally placed dental implants grafted with a xenograft (Group A) and 50 consecutive patients with subcrestally placed dental implants without any grafting material (Group B) were reviewed. For each implant, the radiographs after placement were compared to images from the last follow‐up visit and evaluated regarding the following: 1) degree of subcrestal positioning of the implant, 2) changes of marginal hard‐tissue height over time, and 3) whether marginal hard‐tissue could be detected on the implant platform at the follow‐up visit. Results: The mean marginal loss of hard tissues was 0.11 ± 0.30 mm for Group A and 0.08 ± 0.22 mm for Group B. Sixty‐nine percent of the implants in Group A and 77% of the implants in Group B demonstrated hard tissue on the implant platform. There were no statistically significant differences between the groups regarding marginal peri‐implant hard‐tissue loss. Conclusion: The present study fails to demonstrate that grafting of the remaining osseous wound defect between the bone crest and the coronal aspect of the implant has a positive effect on marginal peri‐implant hard‐tissue changes.     

A Comparative Study of Crestal Bone Loss and Implant Stability between Osteotome and Conventional Implant Insertion Techniques: A Randomized Controlled Clinical Trial Study

Purpose: The aim of this prospective randomized controlled clinical study was to assess the crestal bone loss and the implant stability in implants that were placed by the osteotome technique compared with the conventional drilling technique. Materials and Methods: Forty‐six screw type Straumann SLA® oral implants (Straumann AG, Waldenburg, Switzerland) were inserted in the anterior segment of maxilla of 30 patients. The implant site was prepared randomly using either osteotome technique (test group) or the conventional drilling technique (control group). Radio frequency analysis (RFA) values at implant placement and after 3 months were recorded. The crestal bone loss was measured using digital subtraction radiography technique after 3, 6, and 12 months. Results: RFA demonstrated a statistically significant higher primary stability for implants in the osteotome group than that of the conventional group (p = .026) at the time of implant insertion. However, there was no statistically significant difference between both groups 3 months after the surgery (p = .06). At month 3, the osteotome group caused significantly more crestal bone loss than the conventional group (p = .04). At months 6 and 12, both groups had comparable bone levels (p = .29). Conclusion: Osteotome technique yielded higher primary stability than conventional drilling technique. However, this technique was not superior to conventional technique after 3 months.     

Short Implants: A Descriptive Study of 273 Implants

Purpose: The study aims to assess the performance of short implants in a series of patients with severe alveolar resorption. Materials and Methods: A review is made of 273 implants measuring 10 mm or less, placed by conventional surgery or using osteotomes, and with a postloading follow‐up of between 18 months and 12 years (mean 81 months). Results: A total of 20 failures were recorded (7.33%), with a global implant survival of 92.67%. The survival rate for 10 mm implants was 92.82%, versus 92.5% in the case of those measuring less than 10 mm. Overall, the failure rate was lowest for the treated surface implants (2.56% vs 4.76%). On considering the implants measuring under 10 mm, the failure rates were similar in both groups (3.77%). Conclusions: Short implants are a good treatment alternative for patients with severe alveolar resorption of both jaws.     

骨劈开技术在上颌前牙种植外科中的应用

介绍骨劈开技术应用于上颌前牙区牙种植,方法简单,实用。方法：对３２例在北京医科大学口腔医院种植中心上前牙区种植患者,采用德ＩＭＺ种植系统相匹配的的特殊骨劈开工具进行局部槽突劈开后,完成４８颗ＩＭＺ种植体植入,种植体均获得初期稳定。其中２５个牙位在种植Ⅰ期手术劈开前测量牙槽嵴顶处唇舌侧移动幅度：平均１．６４ｍｍ（０．８３－２．６ｍｍ）。结果本组所有种植体均完成金属基底烤瓷冠修复,并且负荷一年以上,无     

软组织瓣早期裂开或穿孔对种植体颈缘部骨组织的影响

放射线性片评估种植手术后软件组织瓣早开裂或穿孔对种植体周边缘骨吸收的影响。方法：１７例种植患者,植入的３２颗两段式骨内种植体,其中１７颗出现软组织瓣早期裂开或穿孔,导致种植体早期暴露。根据种植体入当天及种植Ⅱ期手术（安装愈合基台）前的Ｘ线片（根尖片）,测量出种植体颈部边缘骨高度的变化。结果：早期暴露的种植体均产生明显吸收,近中平均１．９５ｍｍ,远中平均２．１５ｍｍ;而正常愈合种植体（非裂开）骨变化     

Effects of Implant Design and Surface on Bone Regeneration and Implant Stability: An Experimental Study in the Dog Mandible

Background: Previous experimental studies have shown a higher degree of bone‐implant contact for surface‐enlarged implants compared with machined implants. Yet, there is insufficient evidence that such implants show higher stability and an increased survival rate. Purpose: The purpose of this investigation was to study the integration and stability of grit‐blasted implants with retention elements on the implant neck, with and without marginal bone defects, compared with machined implants without retention elements. Materials and Methods: After tooth extraction of the mandibular premolars in six dogs, two grit‐blasted, partly microthreaded Astra Tech implants and one standard Branemark implant were bilaterally placed in each dog. On one side, 3 ± 3 mm large buccal defects were created, to expose three to four implant threads. The contralateral side served as control, and no defects were made. The animals were sacrificed after 4 months of healing. Implant stability was measured using resonance frequency analysis at implant installation and after 4 months of healing. Histologic and histomorpho‐metric evaluation was made after 4 months of healing. Results: Resonance frequency analysis indicated that all implants in the test and control groups were osseointegrated after 4 months, with a tendency toward higher implant stability for the Astra Tech implants. There was a statistically significant higher increase in resonance frequency for the Astra test implants compared with their corresponding controls. Histology and histomorphometry showed well‐integrated implants with varying degrees of bone repair at the defect sites. The greater bone‐implant contact for the Astra implants was statistically significant. No significant difference between the implants in amount of bone filling the threads was recorded. Conclusions: The Astra Tech implants tested showed a higher degree of bone—implant contact and higher level of bone regenerated at defect sites compared with the Brånemark implants. Resonance frequency analysis demonstrated a significantly higher increase in the Astra test implants compared with their control groups than did the Brånemark test implants versus their controls.