Pre-fabricated zirconium dioxide implant abutments for single-tooth replacement in the posterior region: success and failure after 3 years of function

Objective. Zirconia implant abutments have gained a much broader clinical use over the past few years. The aim of the present study was to assess the clinical performance of a pre-fabricated zirconium dioxide implant abutment for single-tooth replacement in the posterior region. Materials and methods. Forty implants of the XiVE® S plus screw type (DENTSPLY Friadent, Mannheim, Germany) were inserted in the posterior region of 24 patients and provided with zirconium dioxide abutments (FRIADENT® CERCON® Abutment, DENTSPLY Friadent). The following parameters were used to document the state of soft tissue: modified plaque index, modified sulcus bleeding index and pocket depth. Mesial and distal bone levels were determined on radiographs during the prosthetic treatment and at the 36-month recall. Results. Thirty-seven implants could be followed up after 36 months in function. One patient wearing two abutments was lost to follow-up. One abutment exhibited a rotational misfit after 2 years in function. A further abutment showed the same failure at the 36-months recall appointment. In the remaining 36 implants the soft and hard tissue parameters were indicative of a low inflammatory status. Compared to the baseline situation, a partly significant bone apposition could be observed. Chipping of parts of the veneering ceramic was registered in 22% of the remaining implant restorations. Conclusions. The use of zirconia abutments in this study lead to mainly healthy peri-implant hard and soft tissue conditions but, considering the observed failures after 3 years in function, clinical long-term results should be awaited before recommending full zirconia implant abutments in a posterior indication.     

Palatal positioned implants in severely atrophic maxillae versus conventional implants to support fixed full-arch prostheses: Controlled retrospective study with 5 years of follow-up

Background

To evaluate soft tissue conditions and bone loss around palatal positioned implants supporting fixed full-arch prostheses to rehabilitate edentulous maxillae with horizontal atrophy and compare them with conventional well-centered implants placed in non-atrophic maxillae after a minimum follow-up of 5 years.

Material and Methods

A clinical retrospective study was performed of patients that were rehabilitated with full-arch fixed implant-supported maxillary prostheses and had a minimum follow-up of 5 years after implant loading. Patients were divided into 2 groups: patients with class IV maxilla according to Cawood and Howell and treated with palatal positioned implants (test) and with class III maxilla and treated with implants well-centered in the alveolar ridge and completely surrounded by bone (control). The following variables were assessed: age, sex, frequency of tooth brushing, smoking, type of prosthesis, type of implant, implant success, amount of buccal keratinized mucosa, buccal retraction, probing depth, plaque index, modified bleeding index, presence of mucositis or peri-implantitis and peri-implant bone loss. Statistical analysis was performed applying Chi2 Test and Student’s t-test using alpha set at 0.05.

Results

A total of 57 patients were included: 32 patients with 161 palatal positioned implants (test) and 25 patients with 132 well centered implants (control). No statistically significant differences were found regarding age, sex and smoking, but test group patients reported a significantly higher frequency of daily tooth brushing. Implant success rates were 96.9% for test group implants and 96.0% for control group implants. Peri-implant mucosa retraction was significantly higher in the control group than in the test group (p=0,017). No significant differences were observed either for all the other assessed clinical parameters or for peri-implant bone loss.

Conclusions

Despite its limitations the outcomes of the present study suggest that palatal positioned implants may be a good treatment alternative for patients with severe horizontal maxillary alveolar bone atrophy. Palatal positioned implants presented similar success rates, soft tissue conditions and peri-implant bone loss than well-centered implants placed completely surrounded by bone in non-atrophic ridges. Key words: Atrophic maxilla, bone atrophy, fixed dental prosthesis, dental implants.     

后牙区螺丝固位与黏结固位种植义齿修复效果的比较研究

目的探讨后牙区螺丝同位与黏结固位种植固定义齿临床修复效果的差异。方法选择上下颌后牙区牙列缺损患者42例共70枚种植体．其中24枚采用螺丝固位修复体．46枚采用黏结周位修复体。分别于修复后1年复诊．检测种植体周围边缘骨吸收量、改良菌斑指数（mPLI）、改良出血指数（mSBI）等临床指标以及患者对种植义齿的美观满意度。结果螺丝固位组及黏结固位组平均种植体周围边缘骨吸收量分别为0．78mm和0．68mm：螺丝组与黏结组mPLI平均水P50均为1，mSBI平均水平P50亦均为1：两组美观满意度平均得分P50为1。统计结果显示螺丝固位组与黏结固位组间种植体周围边缘骨吸收量、mPLI、mSBI以及患者满意度的差异均无统计学意义（P〉0．05）。结论后牙区螺丝固位与黏结固位种植义齿短期临床修复效果差异无统计学意义。     

The effect of the design of a mandibular implant-supported zirconia prosthesis on stress distribution

Statement of problemProsthetic complications have been frequently reported in implant-supported complete-arch prosthesis. Prosthetic restorations designed with an all-on-four treatment concept and fabricated from zirconia ceramic may be used to overcome these problems.PurposeThe purpose of this biomechanical study was to evaluate the effects of cantilever length and inclination of implant on the stress distribution in bone tissue, implant, and a monolithic zirconia ceramic-lithium disilicate glass-ceramic superstructure for all-on-four prosthesis.Material and methodsAll-on-four mandibular prosthesis fabricated from a zirconia and lithium disilicate glass-ceramic (LDGC) superstructure was designed with cantilever lengths of either 5 mm or 9 mm and posterior implants with a distal tilt of either 15 or 30 degrees. Stresses were evaluated with a simulated application of a static load of 600 N.ResultsIncreasing implant inclination from 15 to 30 degrees led to a decrease in maximum principal stress (MaxPS) values of approximately 4 to 7 MPa in cortical bone around all implants except the right anterior implant in the designs with short cantilevers and an increase in MaxPS values (approximately 3 to 19 MPa) in the same places in the designs with the long cantilevers. Increasing cantilever length from 5 to 9 mm resulted in an increase in minimum principal stress (MinPS) values of approximately 3 to 13 MPa in the cortical bone surrounding all posterior implants. In the designs with the long cantilever, MaxPS values increased approximately 3 to 4 MPa in spongy bone adjacent to the right posterior implant. An increase in cantilever length also led to higher vMS values at the first and second implant grooves in the right posterior implant in the design with the 15-degree implant tilt. An increase in implant inclination in the design with the short cantilever resulted in lower vMS values at the apex and all grooves of the left posterior implant, whereas in the design with the long cantilever, an increase in implant inclination resulted in lower stress values in the first and second grooves of the same implant. An increase in implant inclination led to in an increase in vMS values in the core structure.ConclusionsIn zirconia ceramic restorations by using an all-on-four design with an LDGC superstructure, short cantilevers may be preferable because they result in a more favorable distribution of stress than long cantilevers. An increase in implant angulation from 15 to 30 degrees decreased MaxPS values in cortical bone.     

Single-blind randomized clinical trial to evaluate clinical and radiological outcomes after one year of immediate versus delayed implant placement supporting full-arch prostheses

Purpose: To evaluate and compare peri-implant health, marginal bone loss and success of immediate and delayed implant placement for rehabilitation with full-arch fixed prostheses. Material and Methods: The present study was a prospective, randomized, single-blind, clinical preliminary trial. Patients were randomized into two treatment groups. In Group A implants were placed immediately post-extraction and in Group B six months after extraction. The following control time-points were established: one week, six months and twelve months after loading. Measurements were taken of peri-implant crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis. Implant success rates were evaluated for the two groups. The study sample included fifteen patients (nine women and six men) with a mean average age of 63.7 years. One hundred and forty-four implants were placed: 76 placed in healed sites and 68 placed immediately. Results: At the moment of prosthetic loading, keratinized mucosa width and probing depth were higher in immediate implants than delayed implants, with statistically significant differences. However, after six and twelve months, differences between groups had disappeared. Bone loss was 0.54 ± 0.39 mm for immediate implants and 0.66 ± 0.25 mm for delayed implants (p=0.201). No implants failed in either group. Conclusions: The present study with a short follow-up and a small sample yielded no statistically significant differences in implant success and peri-implant marginal bone loss between immediate and delayed implants with fixed full-arch prostheses. Peri-implant health showed no statistically significant differences for any of the studied parameters (crevicular fluid volume, plaque index, gingival retraction, keratinized mucosa, probing depth, modified gingival index and presence of mucositis) at the twelve-month follow-up. Key words:Immediate implants, delayed implants, peri-implant health, success rate.     

Comparative evaluation of soft and hard tissue changes following endosseous implant placement using flap and flapless techniques in the posterior edentulous areas of the mandible—a randomized controlled trial

Background

Dental implant-supported restorations have long been used as a successful modality for replacing missing teeth. There are two well-established methods of implant placement. The traditional approach to implant surgery involves raising a mucoperiosteal flap and the alternative approach does not involve reflecting a flap, each having its own advantages and disadvantages. The purpose of the present study was to compare and evaluate the soft and hard tissue changes around endosseous implants placed using flap and flapless surgery in mandibular posterior edentulous sites over a period of time.

Materials and methods

A total of 20 systemically healthy patients with a single edentulous site in the posterior mandible were enrolled in this study and 20 endosseous implants were placed (10 in the flap group and 10 in the flapless group). The peri-implant probing depth was assessed. Radiographic assessment was done for changes in the marginal bone levels at the mesial and distal side of the implant with measurements made at baseline, 6 months, and 12 months. Patient-centered outcomes were assessed by using the visual analogue scale (VAS). All these parameters were statistically analyzed using the Wilcoxon signed-rank test, paired Student t test, and two-way ANOVA test and were considered to be significant if the p value was ≤?0.05.

Results

Twenty patients were enrolled in the present study and endosseous implants were placed. Eighteen subjects were followed up throughout the study period and two patients were excluded from the study. The mean PD in the flapless group was comparatively less than the flap group at 12 months and was found to be statistically significant. During the observation period of 12 months, reduction of crestal bone height around the implants placed by flapless and flap surgery were statistically significant. The flapless group showed less change in the crestal bone height which was statistically significant compared to the flap group. The mean VAS score on day 0 in the flap and flapless group was statistically significant. The flapless group showed significantly less pain when compared to the flap group.

Conclusion

Although the flapless technique of endosseous implant placement had statistically significant less PD, bone loss, and pain than the flap technique, the difference was found to have uncertain clinical significance.

     

78例氧化锆种植体边缘骨吸收5年随访观察

目的：观察氧化锆全瓷修复种植体边缘骨吸收变化,评估氧化锆全瓷修复体长期临床效果。方法：将首都医科大学电力教学医院2014年1月—2016年1月间78例采用氧化锆全瓷修复系统进行固定义齿修复的病例纳为研究对象,随访5年,检测修复体完整性、密合性、种植体存留情况,并检测改良龈沟出血指数（mSBI）、改良菌斑指数（mPLI）及牙周探诊深度（PD）,应用X线片评估种植体边缘骨吸收,使用多元线性回归分析影响骨吸收的相关因素。采用SPSS 19.0软件包对数据进行统计学分析。结果：随访期间,6例患者未按规定复诊,随访脱落,脱落率为7.69%(6/78),剩余72例患者（共80颗种植体,63个修复体）完成随访,种植体均未出现松动、折断、脱落,种植体存留率为100.00%。6个修复体出现崩瓷,2个修复体冠边缘与基台间不密合,无修复体脱落。全口曲面体层片与根尖片提示,边缘骨吸收0～2.03 mm,平均（0.23±0.04）mm。统计分析显示,糖尿病史、修复体种植方式、崩瓷及对颌牙类型影响种植体边缘骨吸收量（P<0.05）。结论：长期随访结果显示,氧化锆种植体存留率高,软组织美学效果好,边缘骨稳定,...     

Tilting of posterior mandibular and maxillary implants for improved prosthesis support

Rehabilitation of atrophied edentulous arches with endosseous implants in the posterior regions is often associated with anatomic problems such as jaw shape and location of the mental loop, mandibular canal, and maxillary sinuses. The purpose of this investigation was to modify the method for implant placement in the posterior part of the jaws to extend fixed implant-connected prostheses further distally, and to reduce the length of cantilevers in complete-arch prostheses without transpositioning the mandibular nerve or performing bone grafting in the maxilla. Forty-seven consecutive patients were treated with implants (25 patients/36 mandibular implants, 22 patients/30 maxillary implants) placed in tilted positions. They were followed a mean of 40 months (mandibles) and 53 months (maxillae). In the mandible, implants close to the mental foramina were tilted posteriorly approximately 25 to 35 degrees. In the maxilla, the posterior implants were placed close to and parallel with the sinus walls and were titled anteriorly/posteriorly approximately 30 to 35 degrees. Patients gained a mean distance of 6.5 mm of prosthesis support in the mandible and 9.3 mm in the maxilla, as a result of implant tilting. There were no implant failures in mandibles. The cumulative success rates in the maxilla at 5 years were 98% for tilted implants and 93% for non-tilted implants. Paresthesias of the mental nerve were observed on 4 sides during the first 2 to 3 weeks after implant placement. Analysis of the load distribution in one mandibular case showed no significant difference between tilted and the non-tilted implants, and the improved prosthesis support was confirmed. Satisfactory medium-term results concerning osseointegration and significant extension of prosthesis support show that the method can be recommended. This technique may allow for longer implants to be placed with improved bone anchorage.     

Implant survival or implant success? Evaluation of implant-based prosthetic rehabilitation in head and neck cancer patients—a prospective observational study

Objectives

Definition of implant success is unclear in prosthetic implant-based rehabilitation of head neck cancer patients.

Materials and methods

Fifty-two patients with 309 inserted implants were included in this prospective observational study. Implant survival (in situ and loaded) and implant success (modified Albrektsson criteria) at 2-year follow-up were evaluated under the influence of patient- and implant-specific variables.

Results

Thirty-nine patients with 234 implants finished the study. Overall implant survival after 2 years was 92.3% (216/234) with an osseointegration rate of 94% (220/234). Implant success was 78.6% (184/234). Main reasons for failure were “bone resorption > 1.7mm” (n = 27, 11.5%) and “implant not in situ or not loaded” (n = 18, 7.7%). Smoking (OR 3.1, p = 0.034), bone grafts (OR 2.4, p = 0.021) and radiation dose > 60 Gy (OR 3.8, p = 0.025) revealed as significant predictors for implant failure.

Conclusion

Implant survival differs significantly from implant success in head and neck cancer patients. Implant success is mainly determined by radiographic peri-implant bone resorption.

Clinical relevance

Dealing with head and neck cancer patients a higher amount of peri-implant bone resorption must be taken into account and warrants for intensified implant monitoring.

     

Radiographic evaluation of marginal bone levels during healing period,adjacent to parallel‐screw cylinder implants inserted in the posterior zone of the jaws,placed with flapless surgery

Objective: The purpose of this study was to compare changes at the marginal bone level adjacent to implants placed with flapless surgery and flap surgery during a stress‐free healing period. Material and methods: Seven hundred and eighty‐five implants were placed in 417 patients with a flapless approach and 459 implants were placed in 227 patients using flap techniques. The marginal bone level was determined radiographically, using digitized panoramic radiographs, at two time points: at implant placement (baseline) and after the healing period. Results: The median follow‐up time was 0.5 years (SD, 1.2; range: 0.3–0.7). Implants placed with flapless surgery had a mean crestal bone loss of 0.5 mm (SD, 0.5; range: ?0.7–2.4) and implants placed with flap surgery had a mean bone loss of 0.5 mm (SD, 0.7; range: ?2.0–3.0) after healing. Differences in bone level changes between smokers and non‐smokers were statistically significant for the flapless group (P<0.01). Conclusions: A radiographic evaluation of marginal bone levels adjacent to implants showed comparable results for implants placed with flapless surgery and flap surgery. Appropriate case selection after virtual planning of the implant position and a sound surgical protocol is necessary for flapless surgery. Smoking habits may compromise the efficacy of flapless implant procedures. To cite this article:
Nickenig H‐J, Wichmann M, Schlegel KA, Nkenke E, Eitner S. Radiographic evaluation of marginal bone levels during healing period, adjacent to parallel‐screw cylinder implants inserted in the posterior zone of the jaws, placed with flapless surgery.
Clin. Oral Impl. Res. 21 , 2010; 1386–1393.
doi: 10.1111/j.1600‐0501.2009.01961.x     

Radiologic follow-up of peri-implant bone loss around machine-surfaced and rough-surfaced interforaminal implants in the mandible functionally loaded for 3 to 7 years

PURPOSE: In this retrospective study, marginal peri-implant bone height around machined and sandblasted/acid-etched interforaminal implants in the mandible was evaluated radiologically at least 3 years after functional loading. MATERIALS AND METHODS: Fifty-one patients, each with 4 interforaminal screw-type implants placed between 1994 and 1998, were included in this study. Of these, 36 patients (70.6%) with a total of 144 implants (76 machined Mk II implants and 68 sandblasted/acidetched Frios implants) were available for follow-up studies. Interforaminal marginal bone loss was evaluated by extraoral rotational panoramic radiographs. In addition, predictive factors such as patient age and sex, nicotine use, implant position, implant life, and site of measurement were recorded, as well as bone loss at surgery (ie, baseline bone loss). Analysis of covariance for repeated measurements was used for statistical analysis. Between-group differences were expressed as least square means +/- standard error. RESULTS: Sandblasted/acid-etched implants showed significantly less marginal bone loss than machine-surfaced implants (2.4 +/- 0.23 mm vs 1.64 +/- 0.27 mm). Implants placed in the anterior of the arch showed significantly more peri-implant bone loss than implants placed in the posterior (P = .0001). DISCUSSION AND CONCLUSIONS: Significantly less long-term peri-implant bone loss was observed for rough implant surfaces compared to machine-surfaced implants. However, it was also demonstrated that both types of implants, in combination with bar-supported overdentures, can produce excellent long-term results in the atrophic edentulous mandible. Mesially placed implants showed more bone resorption than distally positioned implants, independent of surface roughness.     

Implant-supported maxillary overdentures retained with milled bars: maxillary anterior versus maxillary posterior concept--a retrospective study

PURPOSE: The aim of the present retrospective investigation was to evaluate implant-supported maxillary overdentures using either anterior (group 1) or posterior (group 2) maxillary implant placement. MATERIAL AND METHODS: Maxillary overdentures were planned with support by either 4 implants placed in the maxillary anterior region (group 1) or 6 to 8 implants placed in augmented maxillary posterior regions (group 2, bilateral sinus augmentation) and anchored either on an anterior or on 2 bilaterally placed milled bars. Cumulative implant survival rate, peri-implant conditions (marginal bone loss, pocket depth, Plaque Index, Gingival Index, Bleeding Index, and Calculus Index) and the incidence and type of prosthodontic maintenance were assessed and compared for the 2 groups. In addition, the cumulative survival rate for implants placed in grafted regions was compared with that of implants placed in nongrafted regions. RESULTS: Thirty-four patients (16 for group 1 and 18 for group 2) with 179 implants were available for follow-up examination after a mean period of 42.1 +/- 20.1 months. Four initially placed implants failed to osseointegrate and were replaced, but no further losses were seen during the loading period, for a 5-year cumulative implant survival rate of 978%. No differences in implant survival rates were seen between either the group-1 (98.4%) and group-2 (97.4%) concepts or nongrafted (98.0%) and grafted (97.5%) implants. The peri-implant parameters showed a healthy soft tissue, good oral hygiene, and an acceptable degree of peri-implant marginal bone loss. The rigid fixation of all overdentures was associated with a low incidence of prosthodontic maintenance, without any significant differences between the 2 groups. CONCLUSIONS: In well-planned overdenture treatment programs, a high survival rate and excellent peri-implant conditions can be achieved for implants placed in the anterior or posterior maxilla. Rigid anchorage of maxillary overdentures either on an extended anterior milled bar or on 2 bilateral posterior milled bars provides for a low incidence of prosthodontic maintenance.     

应用不翻瓣技术进行后牙区种植义齿修复的临床体会

目的：总结应用不翻瓣技术进行后牙种植义齿修复的临床体会。方法：后牙缺失需要进行种植义齿修复患者53例,男26例,女27例,平均年龄47.4±12.3岁,90颗缺牙。术前均进行CT扫描,三维重建分析缺牙区可用骨长度、宽度和高度,术中环形切除缺牙区黏骨膜进行不翻瓣种植体植入手术,必要时辅助手术导板引导种植体窝洞预备和种植体植入。记录手术耗时时间,术后即刻CT检查植入位置,观察有无并发症的发生,种植体骨结合后完成上部结构修复并定期随访。结果：53例患者应用不翻瓣种植手术成功植入90枚种植体,种植体植入位置良好,术中耗时平均（17.4±5.8）min,无上颌窦底黏膜穿孔、下颌神经损伤、骨壁侧穿等手术并发症,86枚种植体成功修复义齿并经3～10个月随访正常。结论：绝大多数后牙缺牙患者都适合进行不翻瓣种植手术,选择比种植体直径稍大的黏骨膜环切钻更有利于手术,种植体上方皮质骨需要修整后方能使愈合基台准确就位。     

Evaluating the clinical performance of the Osseotite implant: defining prosthetic predictability

A 5-year prospective, multicenter study is in progress at four private dental practices to determine the cumulative implant survival rate and prosthetic outcome when using the Osseotite dental implant in posterior maxillary and mandibular areas. An interim evaluation after 34.4 months of study progress is presented. A total of 219 Osseotite implants were placed in 74 patients (34 women and 40 men with a mean age of 57.8 +/- 15.2 years) using a conventional two-stage surgical protocol and 3- to 6-month healing time. Subsequently, patients were restored with fixed or removable restorations. Nineteen of the 74 patients reported smoking an average of 13.2 cigarettes per day. Restorative treatments included 40 single-unit restorations; 53 splinted 2-, 3-, 4-, and 5-unit implant-supported maxillary and mandibular prostheses; 4 full-arch fixed maxillary prostheses; 1 mandibular fixed/detachable hybrid prosthesis; and 1 mandibular overdenture. The mean time from implant placement to second stage surgery was 6.2 +/- 2.0 months; from restoration and implant loading to the most recent follow-up evaluation was 20.9 +/- 6.8 months. Of the 219 implants placed, three posterior maxillary implants developed infections and were removed prior to second stage surgery. No implant failures occurred at second stage surgery or after implant loading. Using the Kaplan-Meier method, the cumulative implant survival rate was 100% for anterior implants and 98.4% for posterior implants at 28.5 +/- 5.7 months. The cumulative postloading implant survival rate was 100% for both anterior and posterior implants. The results of this study indicate that the Osseotite dental implant achieved a high rate of integration that remained stable during nearly 2 years of implant function. In addition, because no postloading implant failures have occurred, the Osseotite implant has provided a high level of prosthetic predictability.     

Immediate rehabilitation of the completely edentulous jaw with fixed prostheses supported by either upright or tilted implants: a multicenter clinical study

PURPOSE: The aims of this study were to assess the treatment outcome of immediately loaded full-arch screw-retained prostheses with distal extensions supported by both upright and tilted implants for the rehabilitation of edentulous jaws and to compare the outcomes of upright versus tilted implants. MATERIALS AND METHODS: At 4 study centers, 342 Osseotite NT implants were consecutively placed in 65 patients (96 implants were placed in 24 mandibles and 246 implants in 41 maxillae). The 2 distal implants were tilted by 25 to 35 degrees. Provisional full-arch restorations made of a titanium framework and acrylic resin teeth were delivered within 48 hours of surgery and immediately loaded. The final prosthesis was delivered after 3 months of healing. RESULTS: Three implants failed during the first year and another 2 within 18 months of loading in the maxilla. The cumulative implant survival rate for the maxilla was 97.59% for up to 40 months of follow-up. No implant failure was recorded for the mandible. The prosthetic success rate was 100%. Marginal bone loss around upright and tilted implants was similar. Patients were satisfied of their esthetics, phonetics, and function. CONCLUSION: The preliminary results of this study suggest that immediate rehabilitation of the edentulous maxilla and mandible by a hybrid prosthesis supported by 6 or 4 implants, respectively, may represent a viable treatment alternative with respect to more demanding surgical procedures. The clinical results indicate that immediately loaded tilted implants may achieve the same outcome as upright implants in both jaws.     

手术导板对后牙区不翻瓣手术精度的影响

目的:评价后牙缺失患者手术导板辅助实施不翻瓣手术对种植体植入精度的影响。方法:选取2009年3月—2010年6月后牙缺失进行不翻瓣种植手术患者38例,其中男19例,女19例,平均年龄(45.06±11.10)岁,分为非导航手术组和导航手术组2组,非导航手术组男10例、女9例,上颌缺失牙17颗,下颌缺失牙22颗,由手术医师目测决定种植体窝洞预备轴向;导航手术组男9例、女10例,上颌缺失牙14颗,下颌缺失牙17颗,应用手术导板辅助进行种植体窝洞预备。术后CT扫描,以种植体长轴为中心重建缺牙区冠状面和矢状面图像,以角度偏差5°、距离偏差2mm为标准,对种植体植入位置满意度计数,对下后牙缺失病例是否出现尖端接触舌侧骨皮质、有无影响种植体植入长度的种植体计数。应用Stata 7.0软件计算上述指标的百分率并进行2组间χ2检验。结果:经统计学检验分析,与非导航手术组相比,导航手术组种植体颊舌向和近远中向角度误差以及下颌后牙种植体到下颌神经管距离误差满意率较高,下颌后牙种植体尖端接触舌侧骨皮质的发生率较低,并且因骨皮质阻挡、影响种植体植入长度的发生率较低。结论:与非导航手术组相比,手术导板可降低种植体植入角度误差和骨皮质阻挡植入种植体的发生率,使种植体植入位置满意率更高,并显著提高下颌后牙缺失病例的种植体植入长度。     

A fully digital approach to replicate functional and aesthetic parameters in implant-supported full-arch rehabilitation

Purpose

The aim of this technical procedure was to use a fully digital technique (FDT) for full-arch implant support rehabilitation. The FDT was used to transfer the provisional restoration parameters to definitive restorations using intraoral scanners.

Comparison between flapless-guided and conventional surgery for implant placement: a 12-month randomized clinical trial

Objectives

The study was aimed at comparing implants installed with guided and conventional surgery.

Material and methods

Twenty-nine total edentulous patients were selected, and maxillary contralateral quadrants were randomly assigned to static computer-aided implant surgery (S-CAIS): flapless computer-guided surgery, and conventional surgery (CS): flap surgery with conventional planning. Tomography scans were performed at baseline and 10 days after the surgery for deviation measurement, and radiography was done at baseline and after 6 and 12 months, for peri-implant bone level (PIBL) analysis. Peri-implant fluid and subgingival biofilm were collected to evaluate bone markers and periodontal pathogens.

Results

S-CAIS showed less linear deviation at the apical point and the midpoint and less angular deviation (p < 0.05), with greater depth discrepancy in the positioning of the platform (p < 0.05). Higher values of vertical PIBL were observed for the S-CAIS group at baseline (p < 0.05), while lower values of horizontal PIBL were observed for CS (p < 0.05). Bone markers and Tf presented higher levels in CS (p < 0.05). Flapless S-CAIS allowed smaller linear and angular deviations than the conventional technique.

Conclusion

However, PIBL was higher in S-CAIS; the conventional technique led to a greater angiogenic and bone remodeling activity by elevating the angiogenic levels and bone markers.

Clinical relevance

Evaluating the different implant insertion techniques can guide clinical and surgical regarding the accuracy, the release pattern of bone markers, and the peri-implant bone level.

Trial registration

ReBEC-RBR-8556fzp.

     

Use of buccal fat pad to repair post-extraction peri-implant bone defects in the posterior maxilla. A preliminary prospective study

Background

Extensive literature exists about the use of the BFP in the treatment of oral defects but, to our knowledge, no article refers to the use of the BFP as a substitute of the membrane barriers for treatment of peri-implant bone defects. The aim was to evaluate the use of the buccal fat pad as a coating material for bone grafting in the peri-implant bone defect regeneration of immediate implants placed in the posterior maxilla.

Material and Methods

A preliminary prospective study of patients involving immediate implants in which the buccal fat pad was used as a coating material to peri-implant bone defects was carried out. The outcome measures assessed were: postoperative pain and swelling, complications related to buccal fat pad surgery, implant survival and success rates and peri-implant marginal bone loss at 12 months of prosthetic loading.

Results

Twenty-seven patients (17 women and 10 men) with a mean age of 55.3 ± 8.9 years, and a total of 43 implants were included. Two-thirds of the patients reported either no pain or only mild intensity pain and moderate inflammation, two days after surgery. Post-operative period was well tolerated by the patients and no serious complications occurred. None wound dehiscence occurred. Implant survival and success rates were 97.6% and the average marginal bone loss 1 year after loading was 0.58 ± 0.27 mm.

Conclusions

Within the limits of this preliminary study, the use of the buccal fat pad as a coating material for bone grafting in peri-implant bone defects placed in the upper posterior maxilla was a well-tolerated technique by patients; high implant success rate was achieved with a minimal peri-implant marginal bone loss at 12 months of prosthetic loading. Key words:Buccal fat pad, immediate implant, peri-implant bone defect.     

Navigated flapless transmucosal implant placement in the mandible: a pilot study in 20 patients

PURPOSE: The aim of this study was to assess whether navigated flapless transmucosal implant bed preparation allows placement of dental implants in edentulous mandibles. MATERIALS AND METHODS: Each patient was scheduled to receive 4 screw-shaped Ankylos (Dentsply Friadent) implants in the interforaminal region. The VISIT navigation system was used for guided drilling. The mucosa was penetrated without flap elevation. The study protocol did not allow direct visualization of the bone surface during surgery. Data analysis included computed measurements on pre- and postoperative computerized tomographic (CT) images. RESULTS: Twenty patients with fully edentulous mandibles (14 male, 6 female) were included in the study. Computer-based planning for 80 implants was performed intraoperatively. Two implants (2.5%) were not primarily stable because of buccal bone fenestration, which occurred because of uncontrollable shifting of the dental implant drill. These implants were immediately removed. Postoperative CT image evaluation revealed a mean deviation of 0.7 mm in all directions. CONCLUSIONS: Navigated flapless transmucosal interforaminal implant placement was found to be a precise, predictable, safe procedure in patients with smooth wide regular mandibular ridges. The technique was less accurate and more complicated in areas where irregular bone existed.