Immediate function of cortically anchored disk-design implants without bone augmentation in moderately to severely resorbed completely edentulous maxillae.

The completely edentulous maxilla remains a challenge in implant dentistry. Conventional two-stage surgical techniques require two independent invasive surgeries separated by a 5-6-month healing period. In addition, an increased risk of trauma to the implant-bone interface may be caused by a removable transitional complete denture during the interim submerged period, which can compromise implant success or increase crestal bone loss around the implants during initial bone healing. The purpose of this clinical trial was to evaluate the safety and efficacy of immediately loading a fixed implant-supported prosthesis without bone augmentation in moderately to severely resorbed, completely edentulous maxillae. Over a 41-month period, 783 titanium implants (627 laterally inserted disk implants, with or without 156 axially inserted Structure implants) were placed in 72 consecutive patients with completely edentulous maxillae using an immediate loading protocol. After 6 months of function, the fixed restorations were removed and each implant status was verified using radiographs, Periotest evaluations, clinical osseointegration criteria, and torque testing at 20 N-cm. Six months postoperatively, 98% of the implants were radiologically and clinically osseointegrated. Fifty-six gold screws (7%) required retightening after 10 months, but no screw fractures occurred during this study period. The postrestorative follow-up of these patients ranged from 6 to 48 months. As of this report, all of the fixed prostheses remain functional, and no additional implants have been lost. This clinical trial demonstrates that immediate loading of nonsubmerged, laterally inserted disk-design implants may provide adequate primary anchorage and longterm osseointegration in completely edentulous maxillae. The initial multicortical anchorage afforded by the disk-design implant in this study, coupled with biomechanical splinting of the disks (sometimes with more traditional root-form design implants) using a rigid prosthesis, permits a one-stage predictable implant procedure offering rapid restoration of patients to masticatory function.     

Immediate loading of implants in the edentulous maxilla: use of an interim fixed prosthesis followed by a permanent fixed prosthesis: a 32-month prospective radiological and clinical study

Purpose: The aim of this study was to prospectively evaluate the survival rate of splinted and immediately loaded Straumann sandblasted, large-grit, acid-etched, solid-screw dental implants in the edentulous maxilla after 32 months of loading.
Materials and Methods: Twenty-eight patients (mean age 63 years) with edentulous maxillae received 168 implants (six each) and an implant-supported fixed interim prosthesis within 24 hours after surgery. After a mean healing time of 15 weeks, the patients received permanent screw-retained prostheses. Clinical and radiological examinations were made at implant placement and after 8, 20, and 32 months of loading. All permanent prostheses were removed at the 32-month follow-up; implant stability was checked with a torque device, and the implant stability quotient was determined with resonance frequency analysis.
Results: Mean marginal bone loss from baseline to 8 months after loading was 1.6 mm (SD 1.16; p  = .094), from 8 to 20 months 0.41 mm (SD 0.63; p  = .094), and from 20 to 32 months 0.08 mm (SD 0.49; p  = .039). The 32-month cumulative survival rate was 98.2%.
Conclusions: The 32-month survival of solid-screw implants – immediately loaded within 24 hours after placement – was similar to survival rates reported for solid-screw implants with conventional loading. Immediate loading and splinting of implants in the edentulous maxilla is a viable treatment alternative.     

Achieving immediate function with provisional prostheses after implant placement: a clinical report

When using a conventional implant treatment protocol in edentulous patients, reduced function and comfort for up to 6 months after implant surgery is inevitable until bone healing is complete and a prosthesis is securely attached to the implants. The following report highlights 2 treatment modalities that enable immediate function by inserting provisional prostheses immediately after implant placement.     

“All-on-4”种植即刻修复技术的临床应用研究

目的：评价应用＂All-on-4＂种植即刻修复技术对牙列缺失患者进行种植即刻修复的临床效果,探讨其技术要点及临床意义。方法：2008年4月至2009年11月共29例患者（男15例,女14例）接受了＂All-on-4＂种植即刻修复。29例（上无牙颌8例,下无牙颌15例,双颌无牙颌6例）共植入140枚种植体,在种植体植入当天完成即刻修复,一共完成35件＂All-on-4＂即刻义齿。即刻修复后观察种植体边缘骨吸收情况、追踪种植体和即刻修复体的存留率、患者满意率。平均追踪14.8个月（10～29个月）。结果：140枚种植体中,8枚于植入后6～8周脱落。其余132枚种植体至最后一次复查临床稳定,种植体存留率：94.3%。上颌种植体存留率89.3%,下颌种植体存留率97.8%,存在统计学差异（p〈0.05）。即刻修复义齿的存留率94%（33/35）。边缘骨吸收程度为（0.8±0.4）mm。患者满意率100%。结论：＂All-on-4＂种植即刻修复技术应用于无牙颌患者近期效果好,患者满意度高。远期效果需要进一步观察。     

临时种植体即刻负载在半颌即刻种植中的应用

目的：评价临时种植体即刻负载在半颌即刻种植中的应用效果。方法：20例半颌即刻种植患者行136枚即刻种植体植入,采用95枚临时种植体即刻负载恢复患者牙列。3-6月后行固定修复。结果：即刻负载临时种植体和即刻种植体成功率达100%。结论：临时种植体即刻负载半颌即刻种植是很好的临床方法。     

Immediate function with fixed implant-supported maxillary dentures: a 12-month pilot study

STATEMENT OF PROBLEM: Immediate occlusal loading of dental implants in the edentulous mandible has proven to be an effective, reliable, and predictable procedure. There is little long-term data available on similar treatments in the edentulous maxilla. PURPOSE: The purpose of this study was to evaluate the 12-month implant survival after immediate loading of 4 to 6 implants with fixed screw-retained prostheses in edentulous maxillae. MATERIAL AND METHODS: Twenty-one patients, edentulous or with remaining teeth to be extracted in the maxilla, received 4 to 6 implants (n=111). The patients were restored with screw-retained fixed provisional prostheses supported by palladium-alloy frameworks within 24 hours after surgery. Insertion torques for implants were at least 40 Ncm. Implants, grouped as tapered or cylindrical screws, were placed in healed bone or extraction sockets. Implants were also classified as either vertical or off-angle. Definitive prostheses were placed after a mean healing time of 18 weeks. Radiographic examinations were made at the time of placement of provisional prostheses and 12 months later. Between-groups bone resorption was compared using 2-way ANOVA (alpha=.05). RESULTS: The mean follow-up time for all of the patients was 20 months (range, 13 to 28 months). The cumulative implant survival rate at the 12-month follow-up visits (after surgery) was 92.8%; the prostheses survival rate was 100%. No significant differences were found between the survival of tapered or cylindrical screw-type implants placed in postextraction sockets versus those in healed edentulous sites or between vertical and off-angle placed implants. Eight implants failed during the first 3 months, 5 of which were the most distal implants. The mean reduction in marginal bone height over the 12-month observation period was 0.84 mm (CI 95%; 0.68-0.99 mm). CONCLUSIONS: In this study with 12-month follow-up, 4 to 6 implants were sufficient to successfully support fixed implant screw-retained prostheses in the edentulous maxillae of 21 patients.     

Immediately loaded implants supporting fixed prostheses in the edentulous maxilla: a preliminary clinical and radiologic report

PURPOSE: To evaluate the survival rate of immediately loaded ITI sand-blasted, large-grit, acid-etched (SLA) solid-screw dental implants in the edentulous maxilla after 8 months of loading. MATERIALS AND METHODS: Twenty-eight patients (mean age 63 years) with edentulous maxillae each received 6 implants and 1 implant-supported fixed provisional prosthesis within 24 hours after surgery. After a mean healing time of 15 weeks, the patient received a definitive, screw-retained, implant-supported fixed prosthesis. A total of 168 implants were placed. Clinical parameters were registered after 1 month of loading with the implant-supported fixed prostheses as well as 8 months after implant placement. Radiologic examinations and assessments were made at implant placement and after 8 months. RESULTS: The mean marginal bone level at implant placement was 1.6 mm (range 0 to 5.1; SD 1.1) apical of the reference point (the implant shoulder). The mean marginal bone level at the 8-month follow-up was 3.2 mm (range 0.4 to 5.9; SD 1.1) apical of the reference point. Three implants failed during the healing period. DISCUSSION: The improved results in the present study might be a result of the positive effect of splinting the implants immediately after placement. CONCLUSION: ITI SLA solid-screw implants immediately loaded (ie, loaded within 24 hours of placement) and supporting fixed prostheses had successful survival rates after 8 months. The present results constitute a solid baseline for future follow-up studies.     

部分牙缺失种植即刻功能负荷的临床探讨

目的:对部分牙缺失种植即刻功能负荷进行临床探讨。方法:将NobelBiocare种植体植入颌骨内,种植体植入扭力必须达到35Ncm以上。选择永久基台接在种植体上,用一定的扭力拧紧基台,基台水平印模,按常规制作和即刻戴上临时塑料修复体。6周后再印模,制作和戴上烤瓷修复体。结果:36例65枚种植体中,下颌22例41枚种植体,上颌14例24枚种植体,修复后成功率为98.5%。结论:部分牙缺失种植即刻功能负荷初步临床结果是满意的,其长期效果有待进一步的观察。     

上颌窦底微创提升的短期临床疗效评价

目的：通过临床试验评估一种上颌窦底微创提升技术的疗效。方法试验组11例患者的上颌后牙区行上颌窦底微创提升技术并同期植入短种植体14枚。对照组10例患者进行了使用扩孔钻的上颌窦冲顶技术并同期植入短种植体13枚。两组患者术后6个月行暂冠修复,进行咬合训练及软组织塑形,3个月后永久修复。术后定期复诊,检查患者的上颌窦、种植体骨结合情况,并使用锥形束CT（CBCT）测量骨增量水平。结果试验组及对照组均无种植体松动、脱落及上颌窦炎发生,CBCT显示种植体与周围组织形成良好的骨性结合。经2~28个月随访观察,临床效果良好。试验组和对照组平均窦底垂直骨增量分别为5.87和5.45 mm。结论上颌窦底微创提升联合短种植体同期植入是一种创伤小、操作简单、行之有效的上颌后牙区种植外科技术,可用于上颌窦底垂直骨量严重不足,余留牙槽骨高度不足4 mm的病例。     

Present status of immediate loading of oral implants

PROBLEM: Several conditions must be present to obtain implant integration and long-term clinical success when using the one-stage implant placement procedure with immediate loading. These conditions include (1) primary stability, (2) sufficient bone quality, and (3) elimination of micromovement of the implant before osseous integration is complete. PURPOSE: This report presents the results of research on immediate loading using a new and innovative implant design, Ankylos. METHODS: The author reviewed clinical studies of immediate loaading or oral implants, including two treatment options, removable overdentures and fixed reconstructions. RESULTS: Animal studies have demonstrated that successful osseointegration of Ankylos implants can occur (Figure 2D) when implants are placed and loaded immediately in the presence of some specific conditions. The histological findings involving implants that were placed in humans and immediately loaded showed no fibrous tissue formation (encapsulation). The bone-to-implant contact (osseointegration) was found to be excellent between the immediately-loaded implants and the surrounding alveolar bone. CONCLUSION: The Ankylos implant system with its progressive thread design successfully promotes primary, clinical stability at the time of implant placement. Several animal studies have shown that in implant restorations placed in similar areas of poor bone quality (ie, maxilla and the posterior part of the mandible), the concept of immediate loading can result in long-term clinical success, when loading forces are controlled. Immobilization of the implants and soft diet recommendations that reduce micromovement at the bone-to-implant interface will improve long-term clinical success. In summary, the Ankylos implant is well designed for one-stage placement with immediate loading, as well as for two-stage treatment protocols. Both clinical protocols will result in long-term clinical survival.     

Peri-implant bone changes following tooth extraction, immediate placement and loading of implants in the edentulous maxilla

The aim of this study was to clinically and radiographically evaluate peri-implant bone level changes after rehabilitation of a fully edentulous maxilla by placement of six implants in either fresh extraction sites or healed edentulous ridges up till 18 months after implant placement. Twenty patients with a terminal dentition in the maxillae (11 men, 9 women) received a total of 120 OsseoSpeed implants; 118 implants could be loaded immediately of which 59 were placed in extraction sockets and 59 were placed in healed sites. Within 24 h after surgery, all patients received a chairside-assembled, fibre-reinforced temporary fixed prosthetic reconstruction in occlusion. Six months post-surgery, final screw-retained CoCr (15) or Ti (5) computer numerical control-milled and acrylic-veneered frameworks were placed directly at implant level without interposing abutments. Intraoral radiographs were taken 6 and 18 months after implant placement. Implant survival rate was 100%. Mean marginal bone level was located on average -0.35 mm below the reference point (standard deviation 0.29, range -1.20 to +0.02 mm) 18 months after loading. Whether implants were placed in healed bone sites or fresh extraction sockets did not significantly affect the bone level changes. Furthermore, the use of either CoCr or Ti at the implant level did not significantly affect marginal bone loss. Within the limits of this prospective clinical trial, results seem to indicate that immediate placement and occlusal loading of five to six implants in the edentulous maxilla can be carried out successfully. Whether or not those implants are placed in fresh extraction sockets does not seem to alter the outcome. The present data show a successful 1-year outcome of a treatment protocol involving tooth extraction immediately combined with implant placement and loading.     

The management of a completely edentulous patient using simultaneous maxillary and mandibular CAD/CAM-guided immediately loaded definitive implant-supported prostheses: a clinical report

Functional rehabilitation of a completely edentulous patient with removable prostheses is a clinical challenge. A patient with an edentulous maxilla and mandible received 6 endosseous implants in the maxilla and 5 implants in the mandible using CAD/CAM surgical templates. Definitive maxillary and mandibular implant-supported fixed complete dentures were connected immediately after implant placement using a CAD/CAM-guided implant surgical placement protocol.     

Immediate functional loading of Brånemark system implants in edentulous mandibles: clinical report of the results of developmental and simplified protocols

PURPOSE: This report evaluates the 5-year results of 9 of 10 patients in a clinical investigation of immediate functional loading of Br?nemark System implants in edentulous mandibles, and of 24 patients treated with a simplified protocol for the same indication. The purpose of the paper is to suggest a simple, reliable, and documented method for immediate implant loading of complete-arch mandibular prostheses. MATERIALS AND METHODS: Ten healthy patients in need of full-arch mandibular implant reconstruction (development group) were treated between December 1993 and December 1994 with 130 Br?nemark System standard Implants, placed in fresh extraction and healed sites. Four implants per patient were immediately loaded with acrylic resin fixed prostheses. The prostheses were replaced by metal-framework conversion prostheses approximately 6 weeks later, and definitive metal-reinforced prostheses incorporating all implants were placed after second-stage surgery. An additional 24 patients were treated with a simplified protocol using a total of 144 implants placed between March 1997 and October 2000. In these patients, the acrylic resin prostheses were not disturbed for 3 months, and fewer implants were used with an increasing ratio of implants loaded. Eventually, all Implants were loaded immediately for the last patients treated. RESULTS: The prosthesis survival rate was 100% for the total material. In the developmental group, the implant cumulative survival rate was 80% for the immediately loaded implants after 5 years, while the 2-stage implants reached 96%. Bone level measurements showed no differences between immediate and 2-stage protocols for this group. The implant cumulative survival rate was 97% for the simplified treatment group. DISCUSSION AND CONCLUSION: A predictable and simple concept for loading of immediate implant prostheses in edentulous mandibles was demonstrated. Results from the development of this technique suggest that it may be essential to maintain the initial implant splinting over a healing period of about 3 months and that implant placement between the mental foramina provides optimal support.     

Efficiency of immediately loaded mandibular full-arch implant restorations

Background: The concept of immediately loading dental implants in fully edentulous patients offers patients many benefits, including the ability to eat post placement and improved comfort during healing. This approach may also minimize the number of patient visits when compared with the traditional approach of implant placement and healing over a 3‐ to 4‐month healing period. Purpose: The aim of this study was to compare the number of treatment visits for patients undergoing traditional implant placement and healing with that of patients receiving immediate implant loading prior to construction of the definitive prostheses. Materials and Methods: This case series evaluated two patient groups. Group 1 consisted of seven patients who were edentulous in the mandible. After implant placement, the implants were covered by oral mucosa during 3 to 4 months of healing. During this time patients wore relined mandibular dentures. Group 2 consisted of seven patients who had their implants immediately loaded with fixed prostheses on the day of implant placement. Results: The implants in both groups were integrated successfully; however, the number of patient visits between implant placement and construction of the definitive prostheses was 38 in the conventionally loaded group and 1 in the immediately loaded group. Conclusions: The group with immediate loading required significantly fewer postoperative visits compared with the conventionally loaded group.     

A finite element analysis of stress distribution in bone tissue surrounding uncoupled or splinted dental implants

Background: Several studies on one‐stage surgery in the treatment of the edentulous maxilla with implant‐supported fixed prostheses have reported problems with removable provisional prostheses, which can load the implants in an uncontrollable manner during healing, and jeopardize healing. Immediate splinting of the implants with a fixed provisional prosthesis has been proposed to protect the bone‐implant interface. Purpose: This study used the finite element method (FEM) to simulate stresses induced in bone tissue surrounding uncoupled and splinted implants in the maxilla because of bite force loading, and to determine whether the differences in these stress levels are related to differences in observed bone losses associated with the two healing methods. Materials and Methods: Stress levels in the maxilla were studied using the FEM program TRINITAS (Institute of Technology, Linköping University, Linköping, Sweden) in which all phases – preprocessing/modeling, equation solving, and postprocessing/evaluation – were simulated. Results: Stress levels in bone tissue surrounding splinted implants were markedly lower than stress levels surrounding uncoupled implants by a factor of nearly 9. Conclusion: From a mechanical viewpoint, FEM simulation supports the hypothesis that splinting reduces damage evolution in bone tissue, which agrees with clinical observations.     

Stability measurements of one-stage Br?nemark implants during healing in mandibles. A clinical resonance frequency analysis study.

Using a one-stage surgical protocol, 75 implants ad modum Br?nemark of three different designs were inserted in 15 edentulous mandibles of high bone density. All implants were followed with repeated stability measurements by means of resonance frequency analysis (RFA) from implant placement to connection of the fixed prostheses (3-4 months), in order to evaluate possible stability changes during healing. It was shown that the resonance frequency (RF) values slightly decreased for the majority of the implants during the study period independent of design. Consequently, the results of the present study indicated that the implants were as stable at time of placement as when measured at 3-4 months post-surgery, i.e. when the prostheses were attached. The available data support the concept of direct loading of implants when inserted between the mental interforaminal regions. One implant failed during healing and the corresponding RF measurement disclosed, at six weeks post-surgery, a value being far below the one registered at implant placement. The lowered RF value indicated the failure several weeks before the mobility was clinically diagnosed. The presence or absence of a fixture/abutment junction did not exert any influence on the marginal bone level, as determined radiographically at the end of the short investigation period.     

Horizontal distraction of the anterior maxilla in combination with bilateral sinuslift operation--preliminary report

In many cases alveolar ridge atrophy causes severe alveolar ridge deficiency in horizontal and vertical direction. In cases of severe atrophy of the edentulous maxilla a maxillary retrognathism results. In this article, a new technique of solving this problem prior to implant placement is described. In six patients with severe atrophy of the edentulous maxilla a sinuslift operation and placement of dental implants were carried out in the posterior maxilla. In the anterior part of the maxilla a segmental split osteotomy and placement of two miniplate distractors were performed. One week after surgery distraction started with a distraction speed of 0.5 mm a day until a clinical correct position of the anterior maxilla resulted. Then, the stabilisation period of 12 weeks followed before the distractors were removed and two to four implants were placed in the anterior distracted maxilla. After a second healing period of 4 months the implants were used for loading by a fixed prosthetic superstructure. Six patients were treated by this regime and 58 implants were placed. All implants were loaded by a fixed prosthesis. Distraction was performed without disturbances. Three months after healing new bone was formed in the distraction gap. There was no implant loss. An aesthetic satisfying superstructure with good red and white aesthetics was achieved together with a correct interalveolar relation. Distraction of the anterior part of the maxilla in combination with sinuslift operation is an alternative technique for correction of interalveolar incongruences in the edentulous maxilla and augmentation prior to implant placement.     

Immediate Occlusal Loading of Osseotite® Implants in Mandibular Edentulous Patients: A Prospective Observational Report with 18-Month Data

PURPOSE: To evaluate the efficacy of treatment consisting of placement and immediate occlusal loading of implants in 27 patients with edentulous mandibles. MATERIALS AND METHODS: Twenty-seven patients were treated in two private practice settings. One hundred fifty-one implants were placed and immediately occlusally loaded with fixed implant prostheses (15 cement-retained, 12 screw-retained) on the day of implant placement. The implant-retained prostheses were inserted within 5 hours of implant placement. Patients were followed for at least 18 months. The required criteria for immediate occlusal loading was primary implant stability of at least 30 Ncm of insertion torque. The implant prostheses were removed at least 12 months post-placement and the implants were evaluated for primary clinical stability and radiographic bone apposition to implants. RESULTS: At the 12-month follow-up appointments, cumulative survival rates of 98.0% and 100% were recorded for implants and prostheses, respectively. Three implants failed within 3 months. All other implants were clinically successful. CONCLUSIONS: Immediate occlusal loading of multiple, splinted mandibular implants is an effective treatment when implants are stable at insertion and are rigidly splinted with implant-retained prostheses.     

A modified method of immediate loading using BrÅnemark implants in edentulous mandibles

According to the original protocol, BrÅnemark implants require a two-step surgical procedure in order to become osseointegrated. The two-stage surgery is sometimes uncomfortable for the patient, and recent research has shown that osseointegration can also be achieved with a one-stage technique with early or immediate loading of the implants in good quality bone, which simplifies and shortens treatment for the patient's benefit. The aim of this study was to evaluate the immediate loading of BrÅnemark implants with a screw-retained prosthesis in edentulous mandibles. Forty-three patients each had three BrÅnemark implants of varying lengths and diameters installed in the inter-foramina mandibular area. The implant installation procedures were performed according to the standard protocol with avoidance of over-preparation of the implant sites. The prosthesis framework was prefabricated in advance and was cast and separated into three parts, followed by adjustment in the mouth, with a soldering, impression made in situ; finally, the framework was sent to the laboratory for completion of the bridge. The fixed implant bridge was usually delivered to the patient later the same day. Three of the 129 implants failed to osseointegrate, yielding a success rate of 97.6%, with a follow-up period ranging from 3 to 49 months. The results obtained in this study were encouraging, and thus far this modified method of immediate loading in the anterior edentulous mandible appears to be predictable.     

高龄患者下颌牙列即刻负重种植的修复对策

目的探讨老年患者下颌牙列缺失后采用即刻负重种植技术的治疗方案的制定及临床效果。方法对1例下颌牙列缺失的82岁高龄患者保留上颌残根和不良固定修复体，下颌植入4颗Xive种植体，同期接入TempBase临时基台行复合树脂临时桥修复。术后8个月，参照上颌义齿，完成短牙弓烤瓷固定桥修复体。结果种植体植入后追踪26个月，没有种植体失败。患者对临时义齿及终义齿的咀嚼效能及美学效果均非常满意。结论对高龄患者采用即刻负重种植修复时应严格掌握适应证，同时还要具有前瞻性，必须考虑全面，兼顾高龄患者的生理和心理上的特殊性，综合设计。