A Retrospective Analysis of Early and Immediately Loaded Osseotite Implants in Cross‐Arch Rehabilitations in Edentulous Maxillas and Mandibles Up to 7 Years

Background: Immediate loading of full‐arch restorations yields good results in selected cases, but long‐term follow‐up and the outcome in compromised bone are scarcely evaluated. Purpose: To evaluate immediately loaded Osseotite implants (Biomet 3i, Palm Beach, FL, USA) installed in healed or grafted bone, with regard to implant survival and peri‐implant bone loss up to 7 years in function. Materials and Methods: Information was retrospectively retrieved from 83 patients' records with 749 Osseotite implants supporting immediately loaded semipermanent full‐arch acrylic restorations. Five hundred sixty‐eight (75.8%) implants were placed in healed bone and 181 (24.2%) in augmented bone, regenerated with sinus lifting and/or onlay/inlay grafts with/without biomaterials and membranes. Implant survival and success based on radiological peri‐implant bone loss were registered. Wilcoxon rank sum tests evaluated peri‐implant bone loss in compromised versus healed bone or between jaws or time intervals with p < .05 as statistically significant. Results: Sixteen of 749 implants failed (2.1%), 11/343 in maxilla (3.2%) and 5/406 (1.2%) in mandible. After 7 years, the cumulative failure rate was 9%. Mean peri‐implant bone loss increased to 1.2 mm (SD 1.0) during the first 2 years but remained unchanged thereafter. Around implants in grafted bone, on average, 0.3 mm more bone loss was found. Conclusion: The Osseotite implants offer a predictable long‐term outcome in terms of implant survival and stable peri‐implant bone under immediate loading even in grafted bone. However, the high incidence of technical repair because of fractures of the semipermanent provisionals requires attention because it may be negative from a cost‐benefit perspective. Implants in grafted bone show a tendency to a more pronounced initial bone remodeling without clinical consequence in the long term.     

How to treat two adjacent missing teeth with dental implants. A systematic review on single implant‐supported two‐unit cantilever FDP's and results of a 5‐year prospective comparative study in the aesthetic zone

To conduct a systematic review on the clinical outcome of single implant‐supported two‐unit cantilever FDP's and to conduct a 5‐year prospective comparative pilot study of patients with a missing central and lateral upper incisor treated with either a single implant‐supported two‐unit cantilever FDP or two implants with solitary implant crowns in the aesthetic zone. Medline, Embase and the Cochrane Central Register of Controlled Trials were searched (last search 1 August 2016) for eligible studies. In the comparative pilot study, an implant‐cantilever group of five patients with a single implant‐supported two‐unit cantilever FDP (NobelReplace Groovy Regular Platform) was compared with an implant‐implant group of five patients with two adjacent single implant‐supported crowns (NobelReplace Groovy Regular Platform) in the aesthetic zone. Implant survival, marginal bone level (MBL) changes, pocket probing depth, papilla index and patient satisfaction were assessed during a 5‐year follow‐up period. Five of 276 articles were considered eligible for data extraction. Implant survival ranged from 96·6% to 100%. Marginal bone level changes were higher in the anterior region than in the posterior region. Technical complications occurred more often in the posterior than anterior region. In the 5‐year comparative pilot study, no clinically significant differences in hard and soft peri‐implant tissue levels occurred between both groups. Single implant‐supported two‐unit cantilever FDP’s can be a viable alternative to the placement of two adjacent single implant crowns in the aesthetic zone. Due to technical complications, placement of two‐unit cantilever crowns in the posterior region can be considered unwise.     

Evaluation of Clinical Outcomes and Bone Loss around Titanium Implants with Oxidized Surface: Six‐Year Follow‐Up Results from a Prospective Case Series Study

Purpose: The aim of this prospective study was to assess long‐term clinical outcomes and peri‐implant bone level changes around oxidized implants supporting partial fixed rehabilitations. Materials and Methods: Twenty‐two partially edentulous patients were included in the study. A total of 33 fixed rehabilitations were placed, supported by 54 titanium implants with oxidized microtextured surface. Prostheses were delivered after 3 and 6 months of implant placement in the mandible and maxilla, respectively. Patients were scheduled for follow‐up at 6 and 12 months and then yearly. At each follow‐up, plaque level and bleeding scores were assessed and periapical radiographs were taken. The main outcomes were prosthesis success, implant survival, implant success, and marginal bone level change. Results: Three patients were excluded from the study because they did not attend the 1‐year follow‐up. Nineteen patients, accounting for 49 implants, were followed for at least 6 years after prosthesis delivery. The mean follow‐up duration was 81.8 months (range 75–96 months). One mandibular single‐tooth implant failed after 1 year in a smoker woman. Cumulative implant survival and success at 6 years were 98.0% and 95.9%, respectively. Prosthesis success was 96.7%. The mean peri‐implant bone loss at 6 years was 0.76 ± 0.47 mm. Not significantly (p = .75) greater bone loss was found in the maxilla (0.78 ± 0.14 mm, n = 19) as compared with the mandible (0.74 ± 0.59 mm, n = 30). In the maxilla, bone loss was significantly greater around implants supporting partial prostheses as compared with single‐tooth implants (p = .03). Full patient satisfaction was reported. Conclusion: Implants with oxidized microtextured surface may achieve excellent long‐term clinical outcomes in the rehabilitation of partial edentulism.     

Bone level changes around axial and tilted implants in full-arch fixed immediate restorations. Interim results of a prospective study

Purpose: The aim of this prospective study was to assess clinical outcomes and peri‐implant bone level changes around tilted and axial implants supporting full‐arch fixed immediate rehabilitations up to 60 months of loading. Material and Methods: Forty‐seven patients (22 women and 25 men) were included in the study. Each patient received a full‐arch fixed bridge supported by two axial and two distal tilted implants. Loading was applied within 48 hours of surgery. Patients were scheduled for follow‐up at 6, 12, 18, 24 months, and annually up to 5 years. At each follow‐up, plaque level and bleeding scores were assessed and radiographic evaluation of marginal bone level change was performed. Periapical radiographs were taken using a paralleling technique, and subsequently scanned at 600 dpi. An image analysis software was used to assess bone level. Results: A total of 33 mandibles and 16 maxillae were rehabilitated (two patients received a fixed prosthesis in both arches). One hundred ninety‐six Nobel Biocare implants of 4 mm diameter were placed. The mean follow‐up duration was 52.8 months (range 30–66 months) in the mandible, and 33.8 months (range 22–40 months) in the maxilla. All subjects attended the scheduled follow‐up visits. No implant was lost. No significant difference in marginal bone loss was found between axial and tilted implants in both jaws, at each follow‐up. No significant difference in bone loss was found between mandible and maxilla, for both axial and tilted implants at each comparable time frame, although slightly higher mean values were always found for the mandible. Conclusion: The use of tilted implants in the immediate rehabilitation of fully edentulous jaws is safe and is not associated to a higher marginal bone loss as compared to axially placed implants.     

Morse taper connection implants supporting "planned" maxillary and mandibular bar-retained overdentures: a 5-year prospective multicenter study

Objectives: In contrast to the excellent long‐term outcomes described for implant‐supported mandibular overdentures, less favorable long‐term survival and success rates have been reported for maxillary implants supporting overdentures. The aim of this study was to evaluate the treatment outcome of “planned” bar‐retained maxillary and mandibular overdentures supported by Morse taper connection implants, investigating implant survival, peri‐implant tissue health, marginal bone resorption and prosthetic complications. Material and methods: Over a 2‐year period, 60 patients were enrolled in this study, in four different clinical centers. The overdentures (maxilla 38, mandible 34) were planned with support from four implants anchored on a bar. A total of 288 Morse taper connection implants (Leone Implant System^®) were inserted (152 maxilla, 136 mandible). Implants were evaluated 5 years after insertion. Success criteria included the absence of pain, suppuration or clinical mobility, the distance between implant shoulder and first crestal bone–implant contact (DIB) <2 mm and no exudate history. Results: The overall 5‐year implant survival rate was 98% (maxilla 97.4%, mandible 98.6%), with 282 implants still in function. Among these surviving implants, 278 (98.6%) were classified in the success group. At the 5‐year examination, the mean DIB was 0.7 mm (±0.53). Few prosthetic complications were reported. Conclusions: With “planned” bar‐retained maxillary and mandibular overdentures supported by Morse taper connection implants, satisfactory survival and success rate can be achieved. To cite this article:
Mangano C, Mangano F, Shibli JA, Ricci M, Sammons R, Figliuzzi M. Morse taper connection implants supporting “planned” maxillary and mandibular bar‐retained overdentures: a 5‐year prospective multicenter study.
Clin. Oral Impl. Res. 22 , 2011; 1117–1124
doi: 10.1111/j.1600‐0501.2010.02079.x     

Spontaneous progression of peri-implantitis at different types of implants. An experimental study in dogs. I: clinical and radiographic observations

Aim: The aim of the present study was to analyze tissue reactions to plaque formation following ligature removal at commercially available implants exposed to experimental peri‐implantitis. Material and methods: Six Labrador dogs about 1 year old were used. All mandibular premolars and the three anterior premolars in both sides of the maxilla were extracted. After 3 months four implants representing four different implant systems with different surface characteristics – implant group A (turned), B (TiOblast), C (sandblasted acid‐etched; SLA) and D (TiUnite) – were placed in a randomized order in the right side of the mandible. Three months after implant installation experimental peri‐implantitis was initiated by placement of ligatures in a submarginal position and plaque accumulation. At week 12, when about 40–50% of the supporting bone was lost, the ligatures were removed. During the subsequent 24‐week period plaque accumulation continued. Radiographic and clinical examinations were performed during the ‘active breakdown’ period (plaque accumulation and ligatures) and the plaque accumulation period after ligature removal. The experiment was terminated at week 36. Results: The bone loss that took place during the ‘active breakdown’ period varied between 3.5 and 4.6 mm. The additional bone loss that occurred during the plaque accumulation period after ligature removal was 1.84 (A), 1.72 (B), 1.55 (C) and 2.78 mm (D). Conclusion: Spontaneous progression of experimentally induced peri‐implantitis occurred at implants with different geometry and surface characteristics. Progression was most pronounced at implants of type D (TiUnite surface).     

Bone alterations at implant‐supported FDPs in relation to inter‐unit distances: a 5‐year radiographic study

Objectives: The aim of this 5‐year study was to longitudinally evaluate bone alterations around implants with a conical implant–abutment interface in relation to implant–tooth and inter–implant distances. Material and methods: The patient sample comprised 43 partially dentate patients with a total of 48 implant‐supported fixed dental prostheses (FDPs) supported by 130 Astra Tech^® implants. Following FDP placement (baseline), the patients were enrolled in an individually designed supportive care program. Radiographic examinations were performed at the time of FDP installation, 1 and 5 years of follow‐up. Variables regarding implant position and proximal bone topography at tooth/implant units (n=36) and implant/implant units (n=67) were assessed with the use of a software program after scanning of the radiographs. Results: At tooth/implant units, the mean 5‐year marginal bone loss at the tooth, the implant and the mid‐proximal bone crest was 0.1, 0.4 and 0.2 mm, respectively. The mean longitudinal bone loss at the implant/implant units was 0.5 mm at the implants and 0.3 mm mid‐proximally. Multilevel regression analysis revealed that at implant/implant units, the change in the bone‐to‐implant contact level was a significant predictor with regard to the 5‐year mid‐proximal bone‐level change, whereas the horizontal inter‐unit distance showed a borderline significance (P=0.052). At tooth/implant units, no statistically significant associations were identified. Conclusions: The results of this 5‐year study revealed differences between inter‐implant and tooth–implant proximal areas with regard to bone crest alterations and associated factors. To cite this article:
Chang M, Wennström JL. Bone alterations at implant‐supported FDPs in relation to inter‐unit distances: a 5‐year radiographic study.
Clin. Oral Impl. Res. 21 , 2010; 735–740.
doi: 10.1111/j.1600‐0501.2009.01893.x     

Implant-supported fixed cantilever prosthesis in partially edentulous jaws: a cohort prospective study

Background: Reconstructive procedures present a higher rate of biological costs due to the necessity of bone harvest and grafts, use of semipermeable barriers etc. On the hand, implant supported cantilever prostheses could allow a simpler rehabilitation procedure. Aims: The aim of the present study was to assess the clinical outcome of patients treated with implant‐supported fixed partial dentures (FPD) with cantilever after a mean follow‐up time of 8 years. Material and methods: The study included 45 consecutive partially edentulous patients treated between January 1994 and August 2006 with 59 partial cantilever fixed prostheses supported by 116 ITI^® implants. The primary outcome variable considered was the presence of complications at the subject and bridge level; the secondary outcome variable was marginal bone loss (MBL). The frequency of complications was analyzed according to cantilever location and opposite dentition and tested by Fisher's exact test. A multilevel regression model was constructed to analyze the factors influencing MBL with three levels: subject as the highest, and then implant and site. During the follow‐up period, 11 implants showed a bone loss exceeding the limit for success, out of which two implants showed an infection of the peri‐implant tissue. Results: After an average observation of 8.2 years of cantilever prostheses loading, the implant success and survival rates were 90.5% and 100%, respectively. Besides, the prosthetic success and survival rate were 57.7% and 100%, respectively. Discussion: None of the predictors included in the multilevel model presented a significant impact on the bone loss between baseline and the follow‐up examination. Conclusions: The authors concluded that the prognosis of implant‐supported FPDs and marginal bone loss at implants were not influenced by the position or the length of the cantilever, the location of the bridge and type of opposite dentition. Implant‐supported fixed cantilever prosthesis can be considered a suitable treatment choice.     

Complication and failure rates of fixed dental prostheses in patients treated for periodontal disease

Objectives: To evaluate the biological and technical complication rates of fixed dental prostheses (FDP) with end abutments or cantilever extensions on teeth (FDP‐tt/cFDP‐tt) on implants (FDP‐ii/cFDP‐ii) and tooth‐implant‐supported (FDP‐ti/cFDP‐ti) in patients treated for chronic periodontitis. Material and methods: From a cohort of 392 patients treated between 1978 and 2002 by graduate students, 199 were re‐examined in 2005. Of these, 84 patients had received ceramo‐metal FDPs (six groups). Results: At the re‐evaluation, the mean age of the patients was 62 years (36.2–83.4). One hundred and seventy‐five FDPs were seated (82 FDP‐tt, 9 FDP‐ii, 20 FDP‐ti, 39 cFDP‐tt, 15 cFDP‐ii, 10 cFDP‐ti). The mean observation time was 11.3 years; 21 FDPs were lost, and 46 technical and 50 biological complications occurred. Chances for the survival of the three groups of FDPs with end abutments were very high (risk for failure 2.8%, 0%, 5.6%). The probability to remain without complications and/or failure was 70.3%, 88.9% and 74.7% in FDPs with end abutments, but 49.8–25% only in FDPs with extensions at 10 years. Conclusions: In patients treated for chronic periodontitis and provided with ceramo‐metal FDPs, high survival rates, especially for FDPs with end abutments, can be expected. The incidence rates of any negative events were increased drastically in the three groups with extension cFDPs (tt, ii, ti). Strategic decisions in the choice of a particular FDP design and the choice of teeth/implants as abutments appear to influence the risks for complications to be expected with fixed reconstruction. If possible, extensions on tooth abutments should be avoided or used only after a cautious clinical evaluation of all options. To cite this article:
Brägger U, Hirt‐Steiner S, Schnell N, Schmidlin K, Salvi GE, Pjetursson B, Matuliene G, Zwahlen M, Lang NP. Complication and failure rates of fixed dental prostheses in patients treated for periodontal disease.
Clin. Oral Impl. Res. 22 , 2011; 70–77.
doi: 10.1111/j.1600‐0501.2010.02095.x     

The effect of smoking on survival and bone loss of implants with a fluoride-modified surface: a 2-year retrospective analysis of 1106 implants placed in daily practice

Aim: To compare the survival and peri‐implant bone loss of implants with a fluoride‐modified surface in smokers and nonsmokers. Materials and methods: Patient files of all patients referred for implant treatment from November 2004 to 2007 were scrutinized. All implants were placed by the same experienced surgeon (B. C.). The only inclusion criterion was a follow‐up time of at least 2 years. Implant survival and bone loss were assessed by an external calibrated examiner (S. V.) comparing digital peri‐apical radiographs taken during recall visits with the post‐operative ones. Implant success was determined according to the international success criteria ( Albrektsson et al. 1986 ). Survival of implants installed in smokers and nonsmokers was compared using the log‐rank test. Both nonparametric tests and fixed model analysis were adopted to evaluate bone loss in smokers and nonsmokers. Results: One‐thousand one‐hundred and six implants in 300 patients (186 females; 114 males) with a mean follow‐up of 31 months (SD 7.15; range 24–58) were included. Nineteen implants in 17 patients failed, resulting in an overall survival rate of 98.3% at the implant level and 94.6% at the patient level. After a follow‐up period of 2 years, the cumulative survival rates was 96.7% and 99.1% with the patient and implant as the statistical unit, respectively. Implant survival was significantly higher for nonsmokers compared with smokers (implant level P=0.025; patient level P=0.017). The overall mean bone loss was 0.34 mm (n=1076; SD 0.65; range 0–7.1). Smokers lost significantly more bone compared with nonsmokers in the maxilla (0.74 mm; SD 1.07 vs. 0.33 mm; SD 0.65; P<0.001), but not in the mandible (0.25 mm; SD 0.65 vs. 0.22 mm; SD 0.5; P=0.298). Conclusion: The present study is the first to compare peri‐implant bone loss in smokers and nonsmokers from the time of implant insertion (baseline) to at least 2 years of follow‐up. Implants with a fluoride‐modified surface demonstrated a high survival rate and limited bone loss. However, smokers are at a higher risk of experiencing implant failure and more prone to show peri‐implant bone loss in the maxilla. Whether this bone loss is predicting future biological complications remains to be evaluated.     

悬臂梁式种植固定义齿的回顾性研究

目的:评价悬臂梁式种植固定义齿的长期临床效果。方法 :采用回顾性研究方法 ,收集2005-01—2011-06,在我科室采用悬臂梁式种植固定义齿修复58例患者(60个修复体,共103枚种植体)的临床及影像学资料。记录种植体的失败个数、修复体失败个数、边缘骨吸收情况、机械及生物并发症情况。结果:随访期内无种植体失败,有3个修复体失败。种植体7年累计存留率100%,修复体7年累计存留率为92.3%。随访期内并未见严重的边缘骨吸收,近悬臂端种植体周边缘骨吸收为(0.08±0.12)mm,远悬臂端种植体周边缘骨吸收为(0.09±0.14)mm。8个修复体(13%)、14枚种植体(14%)发生生物学并发症,11个修复体(18.3%)出现机械并发症。结论:本研究初步证实悬臂梁式种植固定义齿的修复方式临床效果是可靠的,可作为临床种植设计的一个可选方案。因较高的机械并发症,在选择螺丝固位方式时需加以注意。     

Maxillary Overdentures Supported by Anteriorly or Posteriorly Placed Implants Opposed by a Natural Dentition in the Mandible: A 1‐Year Prospective Case Series Study

Background: For maxillary overdenture therapy, treatment guidelines are missing. There is a need for longitudinal studies. Purpose: The purpose of this 1‐year prospective case series study was to assess the treatment outcome of maxillary overdentures supported by six dental implants opposed by natural antagonistic teeth in the mandible. Materials and Methods: Fifty patients were treated with a maxillary overdenture supported by six dental implants, either placed in the anterior region (n = 25 patients) or in the posterior region (n = 25 patients). Items of evaluation were the following: survival of implants, condition of hard and soft peri‐implant tissues, and patients' satisfaction. Results: One‐year implant survival rate was 98% in the anterior group and 99.3% in the posterior group. Mean radiographic bone loss in the anterior and posterior groups after 1 year of loading was 0.22 and 0.50 mm, respectively. Mean scores for plaque, calculus, gingiva, bleeding, and pocket probing depth were low, and patients' satisfaction was high, with no differences between the groups. Conclusion: Six dental implants placed in either the anterior region or the posterior region of the edentulous maxilla, connected with a bar, and opposed by antagonistic teeth in the mandible supply a proper base for the support of an overdenture.     

A prospective,multi‐center study assessing early loading with short implants in posterior regions. A 3‐year post‐loading follow‐up study

Background

Few prospective studies about early loading of short implant have been available and very little evidence exists on the outcomes longer than 3 years.

Purpose

To assess clinical and radiographic outcomes of 6 mm‐short implants placed in the posterior maxilla and mandible applying an early loading protocol.

Materials and methods

Ninety‐five short implants (6 mm‐short, Ø 4 mm) were placed in 45 subjects at 3 study sites, 2 or 3 implants per subject, using a one‐stage surgical procedure and loaded with a screw‐retained splinted fixed prosthesis 6 weeks later. Follow‐up took place at 6, 12, 24, and 36 months after loading. Marginal bone level changes, implant survival, clinical variables, and adverse events were assessed.

Results

The survival rate for all implants placed was 95.8%. From implant loading to 3 years follow‐up, mean marginal bone level changes were minimal (0.07 ± 0.49 mm) and the peri‐implant soft tissue status was healthy. No major technical or biological complications occurred except for the 4 early implant losses.

Conclusion

Three‐year data indicates that the use of splinted 6 mm‐short implants is a viable treatment in posterior regions with low marginal bone resorption. Early loading after 6 weeks should be taken cautiously in patients with known risk factors.     

Bone level alterations at implants placed in the posterior segments of the dentition: outcome of submerged/non-submerged healing. A 5-year multicenter, randomized, controlled clinical trial

Objective: To determine if longitudinal bone level change at Astra Tech^? implants placed in the posterior part of the dentition was influenced by the healing conditions provided following implant placement, i.e., submerged or non‐submerged healing. Material and methods: Eighty‐four patients and 115 fixed partial dentures (FPDs or cases) entered the study. The cases were randomized into two implant installation groups: initially non‐submerged (group A) or initially submerged (group B) implants. Three hundred and twenty‐four implants were installed (group A=153; group B=171): 145 in the maxilla and 179 in the mandible. Radiographs from the implant sites were obtained at FPD insertion (baseline) and subsequently every 12 months. In the radiographs, the position of the marginal bone at the mesial and distal aspects of the implants was determined and the radiographic (Rx) bone level change over time was calculated. Results: Seven implants failed to integrate (four in group A and three in group B). During the 5 years of monitoring, three implants had to be removed and 35 implants were lost to follow‐up. The Rx bone level alteration that occurred during year 1 was 0.02±0.38 mm in group A and 0.17±0.51 mm in group B. During the subsequent 4 years there was some further Rx bone loss in group B (0.02±0.62 mm), while in group A there was some gain of bone (0.07±0.5 mm). Conclusion: The peri‐implant bone level change and number of biological complications that took place during the 5 years was small and unrelated to the surgical protocol used for implant placement.     

Vertical augmentation with interpositional blocks of anorganic bovine bone vs. 7‐mm‐long implants in posterior mandibles: 1‐year results of a randomized clinical trial

Objectives: To evaluate whether 7‐mm‐long implants could be an alternative to longer implants placed in vertically augmented posterior mandibles. Materials and methods: Sixty patients with posterior mandibular edentulism with 7–8 mm bone height above the mandibular canal were randomized to either vertical augmentation with anorganic bovine bone blocks and delayed 5‐month placement of ≥10 mm implants or to receive 7‐mm‐long implants. Four months after implant placement, provisional prostheses were delivered, replaced after 4 months, by definitive prostheses. The outcome measures were prosthesis and implant failures, any complications and peri‐implant marginal bone levels. All patients were followed to 1 year after loading. Results: One patient dropped out from the short implant group. In two augmented mandibles, there was not sufficient bone to place 10‐mm‐long implants possibly because the blocks had broken apart during insertion. One prosthesis could not be placed when planned in the 7 mm group vs. three prostheses in the augmented group, because of early failure of one implant in each patient. Four complications (wound dehiscence) occurred during graft healing in the augmented group vs. none in the 7 mm group. No complications occurred after implant placement. These differences were not statistically significant. One year after loading, patients of both groups lost an average of 1 mm of peri‐implant bone. There no statistically significant differences in bone loss between groups. Conclusions: When residual bone height over the mandibular canal is between 7 and 8 mm, 7 mm short implants might be a preferable choice than vertical augmentation, reducing the chair time, expenses and morbidity. These 1‐year preliminary results need to be confirmed by follow‐up of at least 5 years. To cite this article:
Felice P, Pellegrino G, Checchi L, Pistilli R, Esposito M. Vertical augmentation with interpositional blocks of anorganic bovine bone vs. 7‐mm‐long implants in posterior mandibles: 1‐year results of a randomized clinical trial.
Clin. Oral Impl. Res 21 , 2010; 1394–1403.
doi: 10.1111/j.1600‐0501.2010.01966.x     

Comparison of two early loading protocols in full arch reconstructions in the edentulous maxilla using the Cresco prosthetic system: a three-arm parallel group randomized-controlled trial

Objectives: Appraise the feasibility of interchanging conventional components of a fixed dental prosthesis (FDP) with those of Cresco in two different early loading protocols. Material and methods: In five centers patients with an edentulous, fully healed maxilla were recruited to partake in a three‐arm blinded randomized‐controlled trial (RCT). Each patient received 5/6 implants using a single‐stage surgery approach to support a 10/12‐unit FDP. The implants used were SLA solid screw two‐part implants. In test groups 1 and 2 components from Cresco were used and the implants loaded 10 days or 6–8 weeks post‐implant placement. Group 3 received their FDP fabricated with conventional components 6–8 weeks post‐implant placement. Patients were followed up 3 years. Results: Of 36 patients, 30 remained after 3 years. The adjusted means and ranges of changes in crestal bone levels were ?0.65, ?0.5 and ?0.4 mm in groups 1, 2 and 3, respectively. The change from baseline was statistically significant in all treatment groups. Adjusting for the difference in implant depth, there was an expected additional change in bone level of ?0.29 mm by each 1 mm the implant was placed deeper. There was no significant difference between the 6‐8 weeks post‐implant placement loading Cresco group vs. the control group or between the two Cresco groups. Conclusions: The vertical placement has more effect on bone loss than the fabrication technique used for the suprastructure and whether the implants were loaded after 10 days vs. 6–8 weeks. To cite this article :
Jokstad A, Ellner S, Gussgard A. Comparison of two early loading protocols in full arch reconstructions in the edentulous maxilla using the Cresco prosthetic system: a three‐arm parallel group randomized‐controlled trial.
Clin. Oral Impl. Res. 22 , 2011; 455–463.
doi: 10.1111/j.1600‐0501.2010.02156.x     

Professional and patient-based evaluation of oral rehabilitation in patients with tooth agenesis

Objectives: The outcome of oral rehabilitation is usually monitored with clinical tests rather than by patient's perception of change. The aim of this study was to describe the objective measure and subjective perception of oral rehabilitation in patients with tooth agenesis. Material and methods: The study included 129 patients with tooth agenesis rehabilitated with implant‐ or tooth‐supported reconstructions, and a control group of 58 patients. Professional assessments included biological, technical and aesthetic variables. An aesthetic index score included mucosal discoloration, crown morphology, crown color match, occlusal harmony, and papilla level. The Oral Health Impact Profile (OHIP) questionnaire was used to evaluate the patient‐based outcomes. Six OHIP questions were subtracted to evaluate the patient‐based aesthetic outcomes. Results: Severe root resorption was observed in 36% of the patients in whom orthodontic treatment had been performed. Twelve percent of patients had implants with 5–7 mm peri‐implant bone defects. Mucosal discoloration was recorded in 57% of the patients. Twelve percent of the patients had metal visible on the buccal side. The median scores for all five aesthetic variables were acceptable in 92% of the implant reconstructions and for 83% of the tooth‐supported fixed dental prostheses (FDPs). The total OHIP score was inferior in rehabilitated patients with tooth agenesis to that of the control group without tooth agenesis. The total OHIP score after rehabilitation was <50 for 95% of the patients with tooth agenesis. The six OHIP questions concerning aesthetics demonstrated patient‐based aesthetic problems in 41% of patients treated with implant‐supported reconstructions and 47% of patients treated with tooth‐supported FDPs. Ninety‐eight percent of the group treated with implant‐supported reconstructions and 84% of the patients in the tooth‐supported FDP group were very satisfied or satisfied with the treatment outcome. Conclusions: Patients with tooth agenesis had a high risk of severe root resorption after orthodontic treatment. A better aesthetic outcome was obtained with implant‐supported reconstructions than with tooth‐supported reconstructions. A positive but not significant correlation was observed between the professional and patient‐based evaluations of aesthetic outcomes.     

Five-year results of fixed implant-supported rehabilitations with distal cantilevers for the edentulous mandible

Objectives: The purpose of this study was to evaluate the survival rate, success rate and primary complications associated with mandibular fixed implant‐supported rehabilitations with distal cantilevers over 5 years of function. Material and methods: In this prospective multi‐center trial, 45 fully edentulous patients were treated with implant‐supported mandibular hybrid prostheses with distal extension cantilevers. Data were collected at numerous time points, including but not limited to: implant placement, abutment placement, final prosthesis delivery, 3 months and 5 years post‐loading. Biological, implant and prosthetic parameters defining survival and success were evaluated for each implant including: sulcus bleeding ndex (SBI) at four sites per implant, width of facial and lingual keratinized gingiva (mm), peri‐implant mucosal level (mid‐facial from the top of the implant collar, measured in mm), modified plaque index (MPI) at four sites per implant, mobility and peri‐implant radiolucency. Survival was defined as implants or prostheses that did not need to be replaced. Success rate was defined as meeting well‐established criteria that were chosen to indicate healthy peri‐implant mucosa osseointegration, prostheses success and complications. Results: A total of 237 implants in 45 completely edentulous patients were included in the study. In each patient, four to six implants were placed to support hybrid prostheses with distal cantilevers. Cantilevers ranged in length from 6 to 21 mm, with an average length of 15.6 mm. The ages of the patients ranged from 34 to 78 with a mean age of 59.5 years. The survival rate of implants was 100% (237/237) and for prostheses 95.5% (43/45). The overall treatment success rate was calculated as 86.7% (39/45). Of the six patients that have not met the criteria for success, two patients required replacement of the entire prosthesis and four patients presented >four complications events. Conclusion: Fixed implant‐supported rehabilitation with distal cantilever resulted in a reliable treatment modality over the 5‐year observation period. Although biological parameters of MPI, SBI, keratinized tissue and peri‐implant mucosal levels showed statistically significant differences over time, the mean values for each patient remained within the normal limits of oral health. Complications were categorized as biological or technical. The majority of complications were technical complications (54/79) and of these most involved fracture of the acrylic teeth and base (20/54). While the survival rate was 100% for implants and 95.5% for prostheses, the application of strict criteria for treatment success resulted in an overall treatment success rate of 86.7%.     

A prospective 5-year study of fixed partial prostheses supported by implants with machined and TiO2-blasted surface

Purpose The aim of the present study was to evaluate whether there was a difference between machined and TiO₂‐blasted implants regarding survival rate and marginal bone loss during a 5‐year observation period. Materials and Methods A total of 133 implants (Astra Tech Dental Implants; Astra Tech AB, Mölndal, Sweden) were placed in 50 patients at 6 centers in 4 Scandinavian countries. Forty‐eight implants were installed in the maxilla and 85 implants in the mandible. A randomization and a stratification were done, so that each fixed partial prosthesis was supported by at least 1 machined and 1 TiO₂‐blasted implant. The implant‐supported fixed partial prostheses (ISFPP) were fabricated within 2 months after postoperative healing. A total of 52 ISFPP (17 maxillary, 35 mandibular) were inserted. The patients were clinically examined once a year for 5 years. At the annual follow‐up, biological as well as technical complications were recorded. Results Of the 133 implants placed, 3 were reported as failed after 5 years of follow‐up, resulting in an overall cumulative survival rate of 97.6%. The cumulative implant survival rates were 100% for the TiO₂‐blasted implants and 95.1% for the machined implants. No significant difference in survival was, however, found between the machined and TiO₂‐blasted implants after 5 years. The mean marginal bone loss in the maxilla was 0.21 ± 0.83 mm (SD) for the machined implants and 0.51 ± 1.11 mm (SD) for the TiO₂‐blasted implants during the 5‐year observation period. In the mandible, the mean marginal loss was 0.22 ± 1.13 mm for the machined implants and 0.52 ± 1.07 mm for the TiO₂‐blasted implants from baseline to the 5‐year examination. No significant difference in marginal bone loss between the 2 surface groups was found during the 5‐year observation period. Conclusions The present study shows good 5‐year results with small ISFPP in the mandible, as well as in the maxilla. No significant differences were found in failure rate and marginal bone loss around implants with a machined rather than a TiO₂‐blasted surface.     

Food Impaction and Periodontal/Peri‐Implant Tissue Conditions in Relation to the Embrasure Dimensions Between Implant‐Supported Fixed Dental Prostheses and Adjacent Teeth: A Cross‐Sectional Study

Background: Food impaction and periodontal/peri‐implant tissue conditions were evaluated in relation to the embrasure dimensions between implant‐supported fixed dental prostheses (FDPs) and adjacent teeth. Methods: A total of 215 embrasures of 150 FDPs in 100 patients (55 males and 45 females, aged 27 to 83 years; mean age: 56 years) were included in the study. Clinical assessments of the periodontal/peri‐implant mucosal conditions, radiographic assessments of embrasure dimensions, and overall patient satisfaction were used as explanatory variables for the food impaction and periodontal/peri‐implant tissue conditions adjacent to implant‐supported FDPs in the generalized estimating equation (GEE) analysis. Results: Food impaction was reported in 96 (44.7%) of 215 embrasures between implant‐supported FDPs and adjacent teeth. Food impaction was reported more frequently in the embrasures with proximal contact loss than in those with tight contact (P = 0.009). Overall patient satisfaction was influenced negatively by food impaction in the proximal embrasures (P = 0.01). Among embrasure dimensions, only the embrasure surface area (ESA) significantly influenced food impaction (P = 0.03). Significant influences of various embrasure dimensions on the periodontal/peri‐implant mucosal conditions and bone level at the implant were found in the univariate and multivariate GEE analyses. Conclusions: Food impaction between implant‐supported FDPs and adjacent teeth occurred more frequently when proximal contact was lost and ESA increased. Food impaction negatively affected overall patient satisfaction. Embrasure dimensions influenced the periodontal/peri‐implant mucosal conditions and bone level at the implant.