Survival of dental implants in irradiated head and neck cancer patients: a retrospective analysis

Purpose: To study the long‐term survival of dental implants placed in irradiated bone in subjects who received radiation for head and neck cancer. Materials and Method: A retrospective chart review was conducted for all patients who received dental implants following radiation treatment for head and neck cancer between May 1, 1987 through July 1, 2008. Only patients irradiated with a radiation dose of 50 Gy or greater and those who received dental implants in the irradiated field after head and neck radiation were included in the study. The associations between implant survival and patient/implant characteristics were estimated by fitting univariate marginal Cox proportional hazards models. Results: A total of 48 patients who had prior head and neck radiation had 271 dental implants placed during May 1987 to July 2008. The estimated survival at 1, 5, and 10 years was 98.9%, 89.9%, and 72.3%, respectively. Implants placed in the maxilla were more likely to fail than implants placed in the mandible (p = .002).There was also a tendency for implants placed in the posterior region to fail compared with those placed in the anterior region (p = .051). Conclusion: Dental implants placed in irradiated bone have a greater risk for failure. Survival is significantly influenced by the location of the implant (maxilla or mandible, anterior or posterior).     

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     

Rehabilitation of irradiated patients with modified and conventional sandblasted acid-etched implants: preliminary results of a split-mouth study

Purpose: The aim of this study was to evaluate the success rate of chemically modified and conventional sandblasted acid‐etched surface (SLA) titanium implants in irradiated oral squamous cell carcinoma patients. Material and methods: Twenty patients with a mean age of 61.1 years were treated with dental implants after ablative surgery and radio‐chemotherapy of oral cancer. All patients were non‐smokers. The placement of SLA and modSLA implants was performed bilaterally according to a split‐mouth design. All 102 implants (50 SLA, 52 modSLA) placed showed an unloaded healing time of 6 weeks in the mandible and 10 weeks in the maxilla. Mean crestal bone changes using standardized orthopantomographies and clinical parameters like pocket depths, mPII and mBI were evaluated. Results: Of 102 implants, 55 implants (27 SLA implants, 28 modSLA) were located in the maxilla and 47 implants (23 SLA, 24 modSLA) in the mandible. The average observation period was 14.4 months. The amount of bone loss at the implant shoulder of SLA implants was 0.4 mm mesial and 0.4 mm distal. The modSLA implants displayed a bone loss of mesial 0.3 mm and distal 0.3 mm. Two SLA implants were lost resulting in a success rate of 96%. The success rate of modSLA implants was 100%. Conclusion: Regarding the data found in this investigation, we can conclude that implants with chemically modified and conventional SLA titanium surface show high success rates in irradiated patients. SLA implants with or without a chemically modified surface regardless of the location can be restored with a high predictability of success at least in the short time range observed. To cite this article:
Heberer S, Kilic S, Hossamo J, Raguse J‐D, Nelson K. Rehabilitation of irradiated patients with modified and conventional sandblasted, acid‐etched implants: preliminary results of a split‐mouth study.
Clin. Oral Impl. Res. 22 , 2011; 546–551
doi: 10.1111/j.1600‐0501.2010.02050.x     

Implant survival in mandibles of irradiated oral cancer patients

OBJECTIVE: The aim of this study was to analyze long-term implant survival in the mandible after radiotherapy and radical surgery in oral cancer patients. STUDY DESIGN: Between 1990 and 2003, 71 patients (15 females, 56 males; average age 57.8 years, range 16-84.1 years) were treated with dental implants after radiochemotherapy and ablative surgery of oral cancer. Radiation therapy was delivered in daily fractions of 2 Gy given on 25 days (total dose of 50 Gy). Oral defects were reconstructed microsurgically with jejunal, iliac crest or radial forearm grafts. Thereafter 316 dental implants were placed in the non-irradiated residual bone (84; 27%), irradiated residual bone (154; 49%) or grafted bone (78; 25%) at various intervals (mean interval 1.41 (+/- 1.01) years, range 0.34-6.35 years). RESULTS: The mean follow-up time after implant insertion was 5.42 (+/- 3.21) years (range 0.3-13.61 years). The overall 2-, 3-, 5-, and 8-year survival rates of all implants were 95%, 94%, 91% and 75%. Forty-four implants were lost in 21 patients during the observation period. Irradiation of the mandibular bone showed significantly (P = 0.0028) lower implant survival compared with non-irradiated mandibular bone. The 8-year survival rate in the non-irradiated residual bone (two loss), irradiated residual bone (29 loss) or grafted bone (13 loss) were 95%, 72% and 54%, respectively. Time of implantation after irradiation showed no statistically significant influence. Implant brand, length or diameter or the incidence of resective surgery on the mandible and gender of patients had no statistically significant influence on implant survival. CONCLUSION: Radiation therapy with 50 Gy was significantly related to shorter implant survival in mandibular bone. Survival was lowest in grafted bone. Time of implant placement had no statistically significant influence on survival under the conditions of this study. Although implant survival is lower in irradiated mandibles, implants significantly facilitate prosthodontic treatment and enhance outcome of oral rehabilitation in cancer patients.     

Benefits of dental implants installed during ablative tumour surgery in oral cancer patients: a prospective 5‐year clinical trial

Objective: This prospective study assessed treatment outcome and patient satisfaction of oral cancer patients with a mandibular overdenture on implants up to 5 years after treatment. Materials and methods: At baseline, 50 consecutive edentulous oral cancer patients, in whom prosthetic problems were expected after oncological treatment, were evaluated by standardized questionnaires and clinical assessments. All implants were installed during ablative tumour surgery in native bone in the interforaminal area. About two‐thirds of the patients (n=31) had radiotherapy post‐surgery (dose >40 Gy in the interforaminal area). Results: At the 5‐year evaluation, 26 patients had passed away and four patients had to be excluded from the analyses, because superstructures were not present, due to persistent local irritation (n=2), loss of three implants (n=1) and the impossibility of making an overdenture related to tumour and oncological surgery‐driven anatomical limitations (n=1). In the remaining 20 patients, the prosthesis was still in function (76 implants). During the 5‐year follow‐up, total 14 implants were lost, 13 in irradiated bone (survival rate 89.4%, dose >40 Gy) and one in non‐irradiated bone (survival rate 98.6%). Peri‐implant tissues had a healthy appearance and remained healthy over time. Patients were satisfied with their dentures. Conclusions: It was concluded that oral cancer patients can benefit from implants installed during ablative surgery, with a high survival rate of the implants, a high percentage of rehabilitated patients and a high denture satisfaction up to 5 years after treatment. To cite this article:
Korfage A, Schoen PJ, Raghoebar GM, Roodenburg JLN, Vissink A, Reintsema H. Benefits of dental implants installed during ablative tumour surgery in oral cancer patients: a prospective 5‐year clinical trial.
Clin. Oral Impl. Res. 21 , 2010; 971–979.
doi: 10.1111/j.1600‐0501.2010.01930.x     

A preliminary report of patients treated with early loaded implants using computerized tomography-guided surgical stents: flapless versus conventional flapped surgery

The objective of this clinical study was to compare the survival rates of early loaded implants placed using flapless and flapped surgical techniques and to determine the bone density in the implant recipient sites using computerized tomography (CT). The study population consisted of 12 patients who were referred implant placement. One group consisted of five patients referred for the placement of 14 implants and treated with a flapless procedure. The other group consisted of seven patients referred for the placement of 45 implants with a conventional flapped procedure. Patients were selected randomly. CT machine was used for pre-operative evaluation of the jaw bone and the mean bone density value of each implant recipient site was recorded in Hounsfield units (HU). All implants were placed using CT-guided surgical stents. The early loading protocols included 2 months of healing in the mandible and 3 months of healing in the maxilla. Single-implant crowns, implant-supported fixed partial dentures, and implant-retained over dentures were delivered to the patients. Of 59 implants placed, one was lost in the conventional flapped group within the first month of healing, meaning overall implant survival rate of 98.3% average 9 months later. The highest average bone density value (801 +/- 239 HU) was found in the anterior mandible, followed by 673 +/- 449 HU for the posterior maxilla, 669 +/-346 HU for the anterior maxilla and 538 +/- 271 HU for the posterior mandible. The results of this study show that the early loading of implants placed utilizing flapless surgical technique with CT-guided surgical stents may be possible.     

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.     

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.     

Early function of splinted implants in maxillas and posterior mandibles, using Brånemark System Tiunite implants: an 18-month prospective clinical multicenter study

Background: Immediate or early loading of implants placed in maxillas and posterior mandibles has been a concern as bone density is often low in these areas, making it difficult to establish good initial implant stability. By adapting implant design and insertion protocols, however, high initial implant stability may be achieved in these regions. Further, a modified implant surface texture has been proved to help in maintaining stability during the initial healing period. Purpose: The aim of the present study was to investigate the clinical performance of oxidized titanium implants (TiUnite?, Nobel Biocare AB, Gothenburg, Sweden) when used for early function in the maxilla and in the posterior mandible, locations where the bone density often is low. A further aim was to evaluate the marginal bone level at oxidized implants and compare it with that of machined‐surface implants used in a previous study. Materials and Methods: Thirty‐one patients were consecutively included in the study, and 37 edentulous areas in maxillas and posterior mandibles were treated. Bruxism and uncontrolled periodontal disease were exclusion criteria. Temporary prostheses were generally placed within 9 days but not after 16 days from implant placement. A previous study applying the same study design and clinical protocol but using machined‐surface implants was used for comparisons. Results: Of the 111 implants installed, 1 failed, giving an overall survival rate of 99.1% after 18 months. The prosthesis survival was 100%. The marginal bone resorption was 0.8 mm (standard deviation ISD], 1.0), as opposed to 1.6 mm (SD, 1.3) in the previous study with machined‐surface implants, but was not statistically significantly different (p= .10). Conclusion: The present clinical protocol (aiming at high primary stability) and the use of oxidized titanium implants for early functional loading in the maxilla and the posterior mandible resulted in a high implant survival rate and a favorable marginal bone level during a follow‐up of 18 months. The difference in marginal bone resorption between the oxidized implants in the present study and the machined implants from a previous investigation with the same study design was not statistically significant.     

A clinical evaluation of implants in irradiated oral cancer patients

In this prospective study, we determined the effects of the time interval between irradiation and implant therapy, implant location, bone-resection surgery, and irradiation dose on implant survival. We analyzed the survival of 446 implants inserted after radiotherapy over a period of up to 14 years in 130 consecutive patients treated for oral cancer. The 10-year overall Kaplan-Meier implant survival percentage is 78%. The difference in survival percentages of implants inserted < 1 year and >/= 1 year after irradiation (76% and 81%, respectively) is not significant. We concluded that implant survival is significantly influenced by the location (maxilla or mandible, 59% and 85%, respectively; p = 0.001), by the incidence of bone-resection surgery in the jaw where the implant was installed (p = 0.04), and by the irradiation dose at the implant site (< 50 Gray or >/= 50 Gray, p = 0.05).     

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.     

Longitudinal follow-up of osseointegrated implants in patients with resected jaws

PURPOSE: To investigate the effects of bone grafting and radiotherapy on implant survival rates. MATERIALS AND METHODS: This follow-up study involved 36 patients with 180 implants who were treated between January 1989 and December 2000 by prosthodontic rehabilitation using osseointegrated implants following jaw resection. They comprised 20 patients with malignant tumors, 12 with benign tumors, and 2 patients each with osteomyelitis and cysts. RESULTS: A total of 15 implants (11 in the maxilla and 4 in the mandible) were removed for various reasons during the follow-up study. Implant survival rates were calculated using the Kaplan-Meier method; the overall survival rate for the 180 implants was 88.6%. Specific implant survival rates were as follows: in residual bone, 73.8% for the maxilla and 95.2% for the mandible; in grafted bone, 80% for the maxilla and 94.1% for the mandible; in irradiated bone, 79.7%; and in nonirradiated bone, 93.5%. DISCUSSION: Radiotherapy, a dose of 30 Gy, was performed in patients with malignant tumors but not in patients with benign tumors, cysts, or osteomyelitis. No differences were found in the results for implants placed due to jaw resection for malignant tumors and those for implants placed due to benign tumors, cysts, or osteomyelitis. Implants lost varied in length from 7 to 18 mm. Among these, loss was more frequent with shorter implants (lengths to 10 mm). CONCLUSION: The clinical results obtained in the present study compare favorably with those obtained by others. However, jaw reconstruction and rehabilitation should not be performed by the oral surgeon alone; oral and maxillofacial function should be restored using a team approach in close cooperation with specialists in prosthodontics and periodontics to improve the result of implant treatment.     

Clinical and radiographic evaluation of small-diameter (3.3-mm) implants followed for 1-7 years: a longitudinal study

Implants with a small diameter may be used where bone width is reduced or in single-tooth gaps with limited mesiodistal space, such as for the replacement of lateral maxillary or mandibular incisors. The purpose of the present longitudinal study was to compare the prognosis of narrow implants (3.3-mm-diameter) to standard (4.1-mm-diameter) implants. Over a 7-year period, 122 narrow implants were inserted in 68 patients to support 45 partial fixed prostheses (PFD) and 23 single-tooth prostheses (ST). Furthermore, 120 patients received 208 standard implants and were restored with 70 PFD and 50 ST, respectively. Clinical and radiographic assessment data were provided. Six (1.8%) out of 330 implants failed. Cumulative survival and success rates were calculated with life-table analyses processed by collecting clinical and radiographic data. For narrow implants, the cumulative survival rate was 98.1% in the maxilla and 96.9% in the mandible. The cumulative success rate was 96.1% in the maxilla and 92% in the mandible. Conversely, standard-diameter implants showed a cumulative survival rate of 96.8% in the maxilla and 97.9% in the mandible. The cumulative success rate was 97.6% in the maxilla and 93.8% in the mandible. Cumulative survival and success rates of small-diameter implants and standard-diameter implants were not statistically different (P > 0.05). Type 4 bone was a determining failure factor, while marginal bone loss was not influenced by the different implant diameters. The results suggest that small-diameter implants can be successfully used in the treatment of partially edentulous patients.     

Bone level changes at implants supporting crowns or fixed partial dentures with or without cantilevers

Objective: The aim of this study was to analyze whether or not a cantilever extension on a fixed dental prosthesis (FDP) supported by implants increased the amount of peri‐implant bone loss or technical complications compared with reconstructions without cantilevers. Materials and Methods: Fifty‐four partially dentate patients with a total of 54 FDPs supported by 78 implants were enrolled in the study. Twenty‐seven FDPs were with cantilever and 27 FDPs were without cantilever (control group). All FDPs were supported by one or two implants and were located in the posterior maxilla or mandible. The primary outcome variable was change in peri‐implant marginal bone level from the time of FDP placement to the last follow‐up visit. FDPs were under functional loading for a period of 3 up to 12.7 years. Statistical analysis was carried out with Student's t‐test. Regression analyses were carried out to evaluate the influence of confounding factors on the peri‐implant bone level change. In addition, implant survival rates were calculated and technical complications assessed. Results: After a mean observation period of 5.3 years, the mean peri‐implant bone loss for the FDPs with cantilevers was 0.23 mm (SD±0.63 mm) and 0.09 mm (SD±0.43 mm) for FDPs without cantilever. Concerning the bone level change at implants supporting FDPs with or without cantilevers no statistically significant differences were found. The regression analysis revealed that jaw of implant placement had a statistically significant influence on peri‐implant bone loss. When the bone loss in the cantilever group and the control group were compared within the maxilla or mandible separately, no statistically significant difference was found. Implant survival rates reached 95.7% for implants supporting cantilever prostheses and 96.9% for implants of the control group. Five FDPs in the cantilever group showed minor technical complications, none were observed in the control group. Conclusion: Within the limitations of this study it was concluded that cantilever on FDPs did not lead to a higher implant failure rate and did not lead to more bone loss around supporting implants compared with implants supporting conventional FDPs. In contrast to these results more technical complications were observed in the group reconstructed with cantilever.     

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.     

Brånemark and ITI dental implants in the human bone-grafted maxilla: a comparative evaluation

Abstract: The development of new characteristics concerning implant surface makes it interesting to clinically compare different implant systems in the bone‐grafted maxilla. The aim of this evaluation was to compare clinical data of a two‐staged procedure on the augmented extremely atrophic maxilla using either Brånemark‐ or ITI‐fixures. In 25 patients (18 females, seven males) the severely atrophied maxilla was reconstructed with autogenous iliac or mandibular bone and either Brånemark or ITI implants. Seventy‐eight Brånemark implants and 80 SLA‐ITI implants were inserted in the augmented bone and the patients were followed between 20 and 67 months post implantation. The bone graft was transplanted to add bony volume in the maxillary sinus, the anterior floor of the nose and/or the alveolar ridge. After a healing period of 4½ months, dental implants were inserted and left for healing for 8 months. Twelve consecutive patients received machine‐surfaced Brånemark fixtures and 13 consecutive patients received SLA‐ITI fixtures. Gradual loading was applied after healing abutment application. After 6 months the permanent prosthetic reconstruction was provided to the patient, either as a fixed or removable bridge. Comparison in survival rate was performed: 15 machined Brånemark fixtures were lost, resulting in an overall survival rate of 81%. Two ITI fixtures were lost, resulting in an overall survival rate of 98%. The results of this evaluation show that sandblasted large grit acid etched surface‐treated ITI implants has a significant higher survival rate than machine‐surfaced Brånemark implants in autogenous grafted maxillary bone.     

Tapered implants in jaws with soft bone quality: a clinical and radiographic 1-year study of the Brånemark System Mark IV fixture

Background: The survival rate of oral implants in soft‐quality bone has been demonstrated to be inferior to that of implants inserted in good‐quality bone. A possible way to increase the survival rate in soft‐quality bone may be to use a tapered implant. Such an implant has been developed and manufactured by Nobel Biocare AB, Gothenburg, Sweden. So far, there have been only a few publications regarding this implant. Purpose: The aim of the study was to compare the outcome of using the tapered Branemark System Mark IV fixture with the outcome of using earlier Brånemark fixtures in a controlled prospective study. Materials and Methods: The study was performed as a multicenter study including seven specialist centers. The material consisted of 40 patients in need of implant‐supported bridges in the maxilla. Twenty‐five patients belonged to the test group, in which the tapered Mark IV implants were inserted, and 15 patients belonged to the control group, in which Branemark Standard or Mark II implants were used. The patients were allocated to the test group or the control group according to randomization schedules. The implants were inserted according to the guidelines for Branemark implants. A two‐stage surgical protocol was used, and abutment connection was made 6 months after fixture insertion. The test group comprised 97 Mark IV implants, and the control group made up 92 implants. The prosthetic procedure followed the guidelines for Brånemark implants, and all patients were provided with full fixed maxillary bridges. The patients were followed up with clinical and radiographie records for 1 year after loading. Results: The survival rate was 96.9% for the Mark IV implants and 98.9% for the control implants. There was no significant difference between the two groups. There was a mean marginal bone loss of 0.2 mm during the observation period, and there was no difference between test implants and control implants. Conclusions: With regard to survival rate and marginal bone level changes, no differences could be demonstrated between the Mark IV tapered implant and the Brånemark implants used earlier. However, compared with earlier results of Brånemark implants in soft‐quality bone, the Mark IV implant demonstrated an improved survival rate.     

Maxillary sinus floor elevation using the (transalveolar) osteotome technique with or without grafting material. Part I: implant survival and patients' perception

Objectives: To analyze the survival and success rates of implants installed utilizing the (transalveolar) osteotome technique, to compare peri‐implant soft tissue parameters and marginal bone levels of osteotome‐installed implants with implants placed using standard surgical procedures, and to evaluate patient‐centered outcomes. Material and methods: During 2000 to 2005, 252 Straumann^® dental implants were inserted in 181 patients. The surgical technique was a modification of the original osteotome technique presented by Summers. In addition to the clinical examination, the patients were asked to give their perception of the surgical procedure, utilizing a visual analogue scale. Results: The cumulative survival rate of the osteotome‐installed implants after a mean follow‐up time of 3.2 years, was 97.4% (95% confidence intervals: 94.4–98.8%). From the 252 implants inserted, three were lost before loading and another three were lost in the first and second year. According to residual bone height the survival was 91.3% for implant sites with ≤4 mm residual bone height, and 90% for sites with 4 mm and 5 mm, when compared with that of 100% in sites with bone height of above 5 mm. According to implant length the survival rates were 100% for 12 mm, 98.7% for 10 mm, 98.7% for 8 mm and only 47.6% for 6 mm implants. Soft tissue parameters (pocket probing depth, probing attachment level, bleeding on probing and marginal bone levels) did not yield any differences between the osteotome‐installed and the conventionally placed implants. More than 90% of the patients were satisfied with the implant therapy and would undergo similar therapy again if necessary. The cost associated with implant therapy was considered to be justified. Conclusion: In conclusion, the osteotome technique was a reliable method for implant insertion in the posterior maxilla, especially at sites with 5 mm or more of preoperative residual bone height and a relatively flat sinus floor.     

Multicenter retrospective study of ITI implant-supported posterior partial prosthesis in Jordan

Purpose: The aim of this multicenter study was to evaluate success and restorative problems of ITI (ITI Dental Implant System®, Straumann AG, Basel, Switzerland) implant‐supported posterior partial prostheses in Jordan. Materials and Methods: One‐hundred forty‐one ITI implants were placed in the posterior region of the mandible or the maxilla in 66 patients at multiple clinical practices in Jordan. The age of the patients ranged from 17 to 85 years. The implants were retrospectively analyzed from the first date of placement in September 1999 until May 2006. Eighty‐three implants (58.87%) were placed in the mandible, and 58 (41.13%) in the maxilla. The implants were loaded with either cement‐retained single‐ or multiple‐tooth replacements. Results: Three maxillary implants of two male patients have been lost (2.13% of the total and 5.12% of the maxillary implants). Failed implants were of wide‐neck type with 6‐mm lengths. Moreover, in another two male patients, two single implants at the maxillary premolar region exhibited significant bone loss from the buccal side of the implant surface (2‐mm bone resorption). Those two implants are still functioning and were included in calculating the survival rate but not the success rate. Therefore, the cumulative survival rate for both arches and genders was 97.87% and that for male patients in the maxillary region was 94.88%. The cumulative success rate for both arches and genders was 96.45% and that for the maxillary region was 86.21%. The corresponding rates concerning implants in female patients and the posterior mandible of both genders were 100% for both survival and success rates. Only one crown (mandibular) and another two abutment bridge (maxillary) were decemented in different patients (2.13%). Conclusions: The survival and success rates of implants placed in male patients and in the maxilla were lower than that of implants placed in female patients and in the mandible. Cement‐retained restorations showed minimal complications.     

A long-term follow-up of 76 Bränemark single-tooth implants

Abstract: In a previous study ( Haas et al. 1995 ), we reported on preliminary results of 76 Brånemark implants placed in 71 patients with single‐tooth gaps. The present study examines the results of the same group over a longer period of time: 55 implants were followed for more than 5 years, 12 for a period between 4 and 5 years and 1 implant for 46 months. One patient died 3 years after implant placement. Five patients lost their implant within 24 months after insertion. The drop‐out rate was 2 implants in 2 patients. The recall rate was thus 97%. Of the 5 implant failures, 2 were located in the maxilla and 3 in the mandible. The Kaplan‐Meier survival probability was 93% after 120 months. 74% of the sites showed healthy peri‐implant soft tissue conditions. At 15 implants (22%) a bone resorption of more than 2 mm was observed on intraoral radiographs. The mean bone resorption was 1.8 mm in the maxilla and 1.3 mm in the mandible and did not increase with time (Pearson correlation coefficient: r=?0.06, P=0.59). Abutment loosening occurred in 7 implants (10%), however all abutments that were fixed with a defined torque subsequently remained stable. Thus the favourable preliminary results could be maintained over an average 66 months, indicating that if implant loss happens it seems to occur during the first 2 years after insertion.