Immediate and Early Loading of Chemically Modified Implants in Posterior Jaws: 3‐Year Results from a Prospective Randomized Multicenter Study

Background: There is a lack of well‐designed prospective, randomized clinical trials evaluating the efficacy of immediate and early loading of implants placed in the partially edentulous posterior maxilla or mandible. Purpose: The aim of this study was to evaluate crestal bone level changes over 3 years following immediate or early loading of Straumann implants with a chemically modified surface (SLActive®, Institut Straumann AG, Basel, Switzerland) placed in the posterior maxilla and mandible. Materials and Methods: Subjects received temporary restorations immediately or 28 to 34 days after surgery, with permanent restorations placed at 20 to 23 weeks. Bone level changes were measured by comparison of standardized radiographs taken on the day of implant placement and 5, 12, 24, and 36 months thereafter. Results: Two hundred thirty‐nine of two hundred sixty‐six patients (89.9%) completed the trial. Implant survival rates were 97.4% and 96.7% in the immediate and early loading groups, respectively (p = not significant). Over 36 months, the mean bone level change for immediately loaded implants was 0.88 ± 0.81 mm versus 0.57 ± 0.83 mm for the early‐loaded group (p < .001). After adjusting for a slight difference in initial placement depth, the time of loading had no significant influence on bone level change. Conclusions: Changes in crestal bone level occurred mostly during the first 5 months postloading. After this bone remodeling period, crestal bone level was stable up to 36 months. Implants with a chemically modified surface are safe and predictable for immediate and early loading in the posterior maxilla and mandible.     

One‐Year Results of a Clinical and Radiological Prospective Multicenter Study on NEOSS® Dental Implants

Background: NEOSS® (Neoss Ltd., Harrogate, UK) dental implant system was introduced on the clinical arena in 2003. It is important that novel implant systems are systematically evaluated in a multicenter setting. Purpose: The aim of this study was to follow a large number of consecutively treated patients, with NEOSS dental implant system, both clinically and radiographically. The current report constitutes the 1‐year data of a planned 5‐year study. Materials and Methods: The study included a total of 177 patients treated with 590 NEOSS implants at 13 clinics in Sweden. The material was composed of 72 males and 105 females treated for single, partial, and total edentulism. Clinical, radiographic, and subjective evaluations were performed. Results: Out of 590 implants, 13 early failures have been reported, corresponding to a 1‐year cumulative survival rate (CSR) of 97.8%. Evaluation of function and esthetics at the 1‐year visit resulted in 100% success for function and 98% success for the esthetic outcome. The mean marginal bone loss was 0.6 mm (SD 1.1) after 1 year in clinical function. No adverse effects of the NEOSS dental implants were reported, and complications were few and similar to those reported for implant treatment in general. Conclusion: The CSR in the present study was 97.8%. No adverse effects of the NEOSS implants were reported, and complications during the study period were few and similar to those reported to for other well‐documented implants system. Based on the present data, we conclude that NEOSS dental implant is a safe and predictable implant system. However, the high number of dropouts in the radiological evaluation must be considered when interpreting the data.     

Multicenter Randomized Clinical Trial: Early Loading of Implants in Maxillary Bone

Purpose: The aim of this study was to show prognostic equivalence between implant loading in the maxilla after 12 weeks versus 4 weeks. Materials and Methods: One hundred four patients, from four centers in this open‐labeled randomized multicenter prospective controlled clinical trial, were assigned to either 12 weeks or 4 weeks of unloaded healing. Two hundred sixty‐nine implants (sand blasted large‐grid, acid etched [SLA] surface, ≥4.1 mm diameter; ≥10 mm length) were inserted and evaluated during an individual 5‐year follow‐up. Primary outcome was implant success after 12 months; prognostic equivalence was characterized by a maximum difference of ±5% in implant failure rates. Results: Implant‐wise 1‐year failure rates were estimated 3.1% (5/163 implants) in the 4 weeks group versus 3.6% (4/112 implants) in the 12 weeks group (95% confidence interval [CI] for the difference ?3.2 –+4.2%); implant‐wise evaluation demonstrated statistically significant prognostic equivalence of 4 and 12 weeks loading. Patient‐wise 1‐year failure rates were estimated 6.7% (n = 4 patients) in the 4 weeks group versus 5.1% (n = 2 patients) in the 12 weeks group (95% CI for the difference ?9.6 –+6.5%). All implant failures occurred within the first 3 months of the individual observation period. Prior bone augmentation, underdimensioned drilling, bone quality, implant type, implant length, implant diameter, residual teeth, and fixing of the restoration did not reveal associations with the implant outcome: trial site, posterior jaw region, and splinting were associated with a higher failure rate. Resonance frequency analysis did not serve as a predictor of implant failures at the time of implant insertion. Conclusion: Loading of standard SLA implants in the maxilla 4 weeks versus 12 weeks after insertion resulted in statistically equivalent failure patterns within a 1‐year follow‐up period; nevertheless, the observed patient‐wise failure patterns of the interim analysis requires further understanding of patient‐individual aspects of the early loading concept.     

Immediate Occlusal Loading of NanoTite™ PREVAIL® Implants: A Prospective 1-Year Clinical and Radiographic Study

Background: Recently, a new implant surface texture, featuring application of nanometer‐scale calcium phosphate has been shown to enhance early bone fixation and formation in preclinical studies and in human histomorphometric studies, which may be beneficial in immediate loading situations. Aim: The purpose of the present prospective clinical study was to, during 1 year, clinically and radiographically evaluate a nanometer scale surface modified implant placed for immediate loading of fixed prostheses in both maxillary and mandibular regions. Materials and Methods: Thirty‐five out of 38 patients who needed implant treatment and met inclusion criteria agreed to participate in the study and were consecutively enrolled. Surgical implant placement requirements consisted of a final torque of a least 25 Ncm prior to final seating and an implant stability quotient above 55. A total of 102 NanoTite? PREVAIL® (NTP) implants (BIOMET 3i, Palm Beach Gardens, FL, USA) (66 maxillary and 36 mandibular) were placed by one investigator, and the majority of these were placed in posterior regions (65%) and in soft bone (69%). A total of 44 prosthetic constructions were evaluated consisting of 14 single‐tooth restorations, 26 fixed partial dentures, and four complete fixed restorations. All provisional constructions were delivered within 1 hour, and the final constructions placed after 4 months. Implants were monitored for clinical and radiographic outcomes at follow‐up examinations scheduled for 3, 6, and 12 months. Results: Of the 102 study implants, one implant failed. The simple cumulative survival rate value at 1 year was 99.2%. The average marginal bone resorption was 0.37 mm (SD 0.39) during the first year in function. According to the success criteria of Albrektsson and Zarb, success grade 1 was found with 93% of the implants. Conclusion: Although limited to the short follow‐up, immediate loading of NanoTite Prevail implants seems to be a viable option in implant rehabilitation, at least when a good initial fixation is achieved.     

Immediate Loading of Palatal Implants in Stillgrowing Patients: a Prospective, Comparative, Clinical Pilot Study

OBJECTIVE: The objective of this prospective, comparative study was to evaluate the potential of allowing immediate (within 72 hours) loading of palatal implants used for maximum orthodontic anchorage. This is in contrast to the standard protocol calling for a healing period of 12 weeks. MATERIALS AND METHODS: Sixteen patients with a mean age of 14.22+/-1.37 years for whom orthodontic treatment with maximum anchorage was indicated were randomized into two groups. In the SB (immediate loading) group (n=8, mean age 14.15+/-1.2 years), the implants were employed to provide maximum anchorage for a 1.2 x 1.2 mm TPA wire in combination with a molar band within 72 hours of insertion. In the KB (conventional loading) group (n=8, mean age 14.30+/-1.57 years), the implants were not used for maximum anchorage until a 12-week healing period had elapsed. Patients in both groups with implants that were clinically unstable after insertion were excluded from the study. After conclusion of the treatment, the implants were explanted and embedded using the sawing-grinding technique after Donath. Bone-implant contact (KIK) was analyzed using Bioquant Osteo software version 7.10.10. RESULTS: The objective of the orthodontic treatment, to achieve maximum anchorage of the first molars, was achieved in both groups. In the SB group, the mean bone-implant contact was 55.0%+/-21.6. In the KB group, the mean bone-implant contact was 73.1%+/-19.8. With a p-value of 0.1661, the difference between the bone-implant contact values was not statistically significant. CONCLUSION: The results of our clinical study demonstrate that when implants are clinically stable following insertion, it seems that a 12-week healing phase during which the implants are not loaded leads to a non-statistically significant improvement in osseointegration.     

牙周受损患者即刻种植与即刻负载的3年前瞻性临床研究

为了避免使用临时性的可摘义齿,维持患者的口腔功能、美观与生活质量,一种临床方法可以帮助牙周受损患者恢复全口缺牙状况：即全牙列拔除后即刻种植,并用种植体支持的临时性丙烯酸树脂固定桥修复。本实验共选择了23位牙周受损患者（11位女性．12位男性：4位吸烟者,4位已控制的糖尿病患者）,治疗前取研究模型并确定垂直向咬合关系。根据外科手术导板或是牙槽骨状态,大部分患者沿牙弓植入了6颗Straumann种植体,多数位于上颔最末端的种植体都有轻度的倾斜以使其位置更靠远中。共计植入168个种植体（其中Straumann146枚,Nobel Biocare 10枚,Biomet 3i 8枚,Lifecore 4枚;上颌植入83枚,下颔植入85枚）。有74枚上颌种植体进行了即刻负载（种植体初期稳定性[ISQm]〉70）．9枚延期负载（ISQm≤70）。下颌85枚种植体全部进行即刻负载（ISQm〉70）。种植前如果未制作固定桥．则在手术过程中取模制作。临时修复体在术后48h内就位（粘固或螺丝固位）。2个月后取终印模,制作种植支持式烤瓷熔附金属冠．通过粘结或螺丝固位于6枚种植体上作为最终修复体。在植入的168枚种植体中．108枚为即刻种植．159枚种植体进行了即刻负载。只有2枚种植体没有发生骨整合（上、下颌各1枚）,3年累积存活率达到98．74％（上颔98.65％．下颌98.82％）。在所有26个即刻负载的修复体中（上颌12个,下颌14个）,6个是粘结固位．20个是螺丝固位,3年累积存活率达到了100％。在牙周受损患者上、下颌中进行即刻负载是一项可行的技术,其临时修复体与最终修复体的累积存活率可达100％。     

Maxillary Implants Loaded at 3 Months after Insertion: Results with Astra Tech Implants after up to 5 Years

Background: To date, clinical studies have mainly focused on early loading of mandibular implants. Recently, there has also been considerable interest in early loading of maxillary implants. Purpose: The purpose of this article is to report the outcome of maxillary implants loaded after a 3‐month healing period and followed up to 5 years. Materials and Methods: Seventeen patients (11 males and 6 females) received 44 Astra Tech implants (Molndal, Sweden) for treatment of single‐tooth (13 cases) and partial edentulism (9 cases). The patients were followed up to 5 years after implant placement:50% of the implants were followed for 3 years and 16% have been followed throughout the observation period. Preoperatively, bone height and width were assessed on radiographs. Marginal bone loss was recorded on intraoral radiographs annually. Results: No implant was lost during the observation period. The average marginal bone loss was 0.5 ± 0.7 mm after 1 year, 0.6 ± 0.7 mm after 3 years, and 0.9 ± 1.6 mm after 5 years. There were no soft‐tissue or prosthetic failures recorded during the observation period. Conclusion: Early loading of Astra Tech implants was highly successful in maxillary partial and single‐tooth cases followed up to 5 years in function.