A 9-14 year follow-up of onlay bone grafting in the atrophic maxilla.

Treatment of the atrophic edentulous maxilla is challenging especially when bone graft procedures are necessary. In this study an onlay bone graft, a saddle or veneer, with or without maxillary sinus floor inlay graft, harvested from the anterior iliac crest, in combination with implants was used in the reconstruction of patients with extreme atrophy in their maxillae. The aim was to investigate treatment outcome, and the impact of gender and smoking, in 44 patients in a prospective, long-term, follow-up study concerning implant survival rate and marginal bone loss adjacent to the surfaces of the implant. Mean follow-up time was 11 years. Of 334 inserted Brånemark implants, with machined surface, 27 failed. Estimated implant survival rate was 90%. Marginal bone loss was 1.8 mm 1 year after implant surgery; 2.3 mm after 5 years; and 2.4 mm after 10 years. There was a significant difference between genders in implant survival. Marginal bone loss differed significantly between smokers and non-smokers up to the 5-year examination and between genders after the 4-year examination. The onlay bone graft, with or without a maxillary inlay graft, results in high implant survival rate, good oral function and stabilised marginal bone. All patients are still wearing their original fixed bridges.

Reconstruction of the atrophic maxilla with interpositional bone grafting/Le Fort I osteotomy and endosteal implants: a 11-16 year follow-up.

A Le Fort I osteotomy and interpositional bone graft in combination with implants was used in the reconstruction of patients with extreme atrophy in their maxillae. Surgery was performed in a two-stage procedure. The patients in this study had conditions with reversed intermaxillary relationships with or without increased vertical intermaxillary distance. The aim of the study was to investigate treatment outcome for patients in a prospective, long-term, follow-up with a mean of 13 years (range 11-16 years), concerning implant survival rate and marginal bone loss adjacent to the surfaces of the implant. The impact of gender and smoking was also investigated. Twenty-six patients were included in the study. Of 167 implants, 24 failed. The implant estimated survival rate was 85% at the end of the follow-up. There was no significant difference between smokers and non-smokers or genders concerning implant survival. Marginal bone loss was 2.5, 2.9, 3.0 and 3.1mm from the implant-abutment junction, after 1, 2, 5 and 10 years, respectively. The bone level stabilised after 2 years. This technique results in good facial morphology, good oral function and aesthetics. All patients are still wearing their original fixed bridges.

Implants and/or teeth: consensus statements and recommendations.

In August 23-25, 2007, the Scandinavian Society for Prosthetic Dentistry in collaboration with the Danish Society of Oral Implantology arranged a consensus conference on the topic 'Implants and/or teeth'. It was preceded by a workshop in which eight focused questions were raised and answered in eight review articles using a systematic approach. Twenty-eight academicians and clinicians discussed the eight review papers with the purpose to reach consensus on questions relevant for the topic. At the conference the consensus statements were presented as well as lectures based on the review articles. In this article the methods used at the consensus workshop are briefly described followed by the statements with comments.

10-year follow-up of onlay bone grafts and implants in severely resorbed maxillae.

Thirty patients with extremely resorbed maxillae had reconstructive bone grafts from the ala iliaca and endosseous implants in a one-stage procedure. The first ten patients constituted a development group and the following 20 patients a routine group. The marginal bone level and implants success rate was evaluated in a prospective long-term follow-up for a minimum of 10 years (10-13 years). Clinical and radiographic examinations were performed at 6 months and then annually up to 5 years. The final examinations were performed at the 10-year follow-up. The bridges were removed at every clinical examination. Marginal bone loss was seen up to the 3-year examination, where it averaged 4.6 mm in the routine group. Between the 3- and 10-year follow-up no significant change was registered. The initial bone loss was probably due to the design of the 3.6 mm conical unthreaded marginal part of the implant. The implant success rate was 83.1% in the routine group. Failures mostly occurred during the first 2 years (14 out of 20). A substantial amount of bone can be gained in patients with extremely resorbed maxillae, when treated with bone graft according to the procedure described in this study.

Implant versus tooth-implant supported prostheses in the posterior maxilla: a 2-year report.

When implants are used for restoration of a jaw with a residual dentition, the possibility of combining implants with natural abutments may be considered. In a longitudinal comparative study, 26 patients (15 women & 11 men, age 49-84 years) with residual anterior dentitions were treated with two different designs of fixed partial dentures bilaterally in the posterior maxilla. On one side the reconstruction was supported by implants only, while on the contralateral side an implant and a tooth in combination were used. The patients were followed at intervals of 3, 6, 12 and 24 months after loading of the implants. 95 implants were placed, of which 11 non-loaded. A total of 10 implants failed, 7 prior to loading and three within the first three months of service (88.0+/-SE 6.7% cumulative survival for tested implants after two years' follow-up). There was no difference in failure rate for the implants in the two different prosthesis designs. The total mean loss of marginal bone height close to the implants was within acceptable standards, but was more pronounced at the implants not combined with teeth. The results indicate a correlation between the prosthesis design and the loss of marginal bone.

Tooth-implant supported fixed prostheses: a retrospective multicenter study.

PURPOSE: The purpose of this retrospective multicenter study on implants combined with natural teeth was to investigate the implant survival rate and loss of marginal bone, as well as indications and complications pertinent to this form of implant therapy. MATERIALS AND METHODS: The study comprised 185 implants in 111 patients from six different clinics in Sweden. Gathering of data, which were taken from patient records, followed a strict protocol. The registrations included indications for treatment, failure of implants, radiographs from baseline and follow-up, and information on complications. RESULTS: The cumulative implant survival was found to be 95.4% (standard error 4.5%) up to 3 years of follow-up. The marginal bone level at baseline was lower in the maxilla compared with the mandible (P = .015), but any further loss did not differ between the jaws. The most severe complication other than loss of osseointegration (6/185) or periimplant infections (4/183) was intrusion of the abutment teeth, which occurred in 5% of the cases. In all instances, the intrusion was seen in constructions with nonrigid forms of connection between the implants and teeth. CONCLUSION: The tooth-implant supported prosthesis using the Brånemark system is in the short term an equally predictable treatment as the completely implant-supported prosthesis concerning implant survival and loss of marginal bone. When combining implants and teeth, a rigid form of connection should be used to prevent tooth intrusion.

Double-quantum excitation in the NMR of spinning solids by pulse-assisted rotational resonance.

We describe a new technique for double-quantum excitation in magic-angle-spinning NMR of powdered solids. The technique is designed to efficiently excite double-quantum coherence in the vicinity of a rotational resonance condition. The offset from rotational resonance allows the double-quantum filtered signals to be observed with high resolution and sensitivity. The method uses rotational excitation of zero-quantum coherence, assisted by radiofrequency pulse cycles. The zero-quantum coherence is converted into double-quantum coherence by a frequency-selective inversion sequence. Experiments on [(13)C(2), (15)N]-glycine demonstrate a double-quantum filtering efficiency of approximately 41% at a sample rotation frequency of 8.300 kHz, which is 1.600 kHz away from the n = 1 rotational resonance. We achieve 32% double-quantum filtering efficiency at a spinning frequency of 9.250 kHz, which is 2.550 kHz away from rotational resonance.

Tooth- and implant-supported prostheses: a retrospective clinical follow-up up to 8 years.

PURPOSE: The purpose of this study was to evaluate clinical treatment outcome of fixed prostheses in different sizes and with combinations of different numbers of teeth and implants as abutments. MATERIALS AND METHODS: A total of 115 implants were placed in 36 patients, 75 (65%) in the maxilla and 40 (35%) in the mandible. The implants were connected to 85 abutment teeth, 50 in the maxilla and 35 in the mandible. Of the prosthetic restorations, 19 were gold ceramic, 17 were gold acrylic, three were titanium acrylic, one was titanium ceramic, and one was titanium composite. The observation period ranged from 14 months to 8.9 years. The treatments comprised both fixed partial dentures supported by one tooth and one implant as well as complete-arch fixed prostheses supported by a number of teeth and implants. RESULTS: A total of nine implants were lost, three during healing and six after loading. The postloading cumulative implant survival rate was 89.8% after 5 years. Five abutment teeth were lost, and of the 41 prostheses included in the study, only two (5%) were lost during the observation period. Marginal bone loss was registered around 46 implants at the 1-year follow-up examination. During the following observation period, only slight changes in the marginal bone level adjacent to the implants and teeth were registered. The magnitude of technical complications was low. CONCLUSION: This investigation confirms the findings in similar studies that treatments with periodontally healthy teeth and implants splinted together in rigid one-piece superstructures show excellent long-term follow-up results.

Survival of the Brånemark implant in partially edentulous jaws: a 10-year prospective multicenter study.

A total of 127 partially edentulous patients, treated according to the Brånemark protocol, was followed for 10 years after completion of prosthetic treatment. The patients ranged in age from 18 to 70 years, and 57% were female. Four hundred sixty-one implants were placed in 56 maxillae and 71 mandibles. In 125 patients, 163 fixed partial prostheses were attached to the implants; a majority of the prostheses (83%) were located in posterior regions. At the end of the 10-year period, 73% of the implants could be traced either as failed or in function, providing cumulative implant survival rates of 90.2% and 93.7% for the maxilla and mandible, respectively. Of the original fixed prostheses, 63% (cumulatively 86.5%) were still in use, whereas the level of continuous cumulative prosthesis function, including primary and remade restorations, was 94.3% at the end of the evaluation period. Marginal bone resorption at the implants was low (mean = 0.7 mm), and mucosal health was good. No severe complications apart from the above-mentioned implant and prosthetic failures were reported. The Brånemark Implant System is a safe and predictable method for restoring partially edentulous patients, as demonstrated by this 10-year follow-up investigation.

Tooth-implant and implant supported fixed partial dentures: a 10-year report.

PURPOSE: The use of implants for prosthetic rehabilitation of partially edentulous patients is increasing. However, the possibilities of placing implants in the posterior part of the mandible are often limited. The purpose of this longitudinal study with 10 years of follow-up was to evaluate the use of short implants supporting fixed partial dentures (FPD) in the posterior part of the mandible, and to compare implant supported FPDs to tooth-implant supported FPDs. MATERIALS AND METHODS: The patient material comprised 23 patients with residual mandibular anterior teeth, and each patient received FPDs unilaterally. On one side the FPD was supported by two implants, and on the other side by one implant and one tooth, thus permitting intraindividual comparison. The distribution of the two types of FPDs in each jaw was randomized. Implant success rates, marginal bone changes, and mechanical complications were studied. RESULTS: The tooth-implant connection did not demonstrate any negative influences on the overall success rates for the 10-year period, nor were the shorter implants found to be less favorable. CONCLUSION: It is suggested that a prosthetic construction supported by both a tooth and an implant may be recommended as a predictable and reliable treatment alternative in the posterior mandible.

A meta-analysis of implants in partial edentulism.

A meta-analytic technique was used to estimate the survival of implants supporting bridges or single crowns in partially edentulous patients. A survey of the literature revealed 66 studies, published between 1986 and 1996. Nine studies on single implants and 10 studies on fixed partial dentures met the inclusion criteria for the meta-analysis. Data from a total of 2686 implants, 570 single crowns (SC) and 2116 in fixed partial dentures (FPD), were analyzed. In order to calculate annual survival rates for individual studies a life-table analysis was conducted. Maximum follow-up time ranged between 1 and 8 years. After 1 year the success rate was calculated to be at least 85.7% for FPD and 97.2% for SC. When the results from the FPD studies were pooled the survival rate was 93.6% after 6-7 years. The corresponding value for SC was 97.5%.

Rigid connections between natural teeth and implants: a technical note.

In the posterior partially edentulous jaw, implants may be used to supplement existing natural dentition. Frequently, the maxillary sinuses and the mandibular nerve preclude the fabrication of freestanding implant-retained prostheses. However, if an implant and a natural abutment are combined, a fixed prosthesis can be fabricated, restoring the arch into the premolar area. The histories of three patients with attachments connecting implant-retained ceramotitanium crowns with crowns on natural abutments are described. A design for a rigid custom-made attachment for the Brånemark system, using standard components with a machine-duplication, spark-erosion technique, is suggested.

Functional loads on freestanding and connected implants in three-unit mandibular prostheses opposing complete dentures: an in vivo study.

In vivo measurements of vertical forces and bending moments during biting and chewing were carried out on 10 three-unit prostheses in the posterior mandibles of five patients. Each patient had two prostheses, one supported by two implants and the other supported by one implant and one tooth. The results demonstrated no major difference in functional load magnitudes related to the support type. The distribution of load between the abutments was influenced more by the prosthesis geometry and implant placement than by the difference in load characteristics of tooth and implant. This conclusion, however, is limited to one implant connected to a tooth, because multiple implants form a considerably stiffer unit than do teeth. An increase in vertical load resulting from cantilever extensions on the prostheses was documented, both at bite fork measurements and during chewing. No substantial lateral bending was registered, probably because the flat occlusal surfaces and the presence of the opposing complete denture reduced lateral forces.

Interpositional bone grafting and Le Fort I osteotomy for reconstruction of the atrophic edentulous maxilla. A two-stage technique.

This study presents the results from ten consecutive patients who, because of insufficient bone volume for conventional implant placement in the maxilla, were treated with an interpositional bone graft and Le Fort I osteotomy. The endosteal implants were placed six months after the osteotomy. A total of 60 screw-shaped titanium implants (Brånemark) were placed, of which three failed to integrate during the six-month healing period. No further implants were lost during the follow-up period, ranging from 15 to 39 months after placement of the implants. All patients received fixed bridges and all have continued to function efficiently.

Bone grafting to the maxillary sinuses, nasal floor and anterior maxilla in the atrophic edentulous maxilla. A two-stage technique.

This study presents the results from 20 consecutive patients treated with an autogenous bone graft from the iliac crest. In ten patients the graft was placed in the maxillary sinuses and the floor of the nose (inlay group). Ten patients, in addition to the inlay graft, had a corticocancellous bone block secured with mini-screws to the anterior maxillary ridge (inlay/onlay group). Endosteal implants (Brånemark) were placed six months after surgery. A total of 136 implants were placed, of which eight failed to integrate during the six-month healing period. A further 15 implants were lost during the follow-up period. For the inlay group the average follow-up period was 22 months and for the inlay/onlay group 19 months. Donor site morbidity was significantly less when iliac bone was harvested with a trephine (inlay group) than in patients treated with our routine procedure for bone harvesting (inlay/onlay group). Surgical technique, donor site morbidity, implant survival and patient acceptance are presented.

A 2-year clinical follow-up study of IPS Empress ceramic inlays.

This study evaluated the clinical quality of 62 Empress restorations placed for 18 patients. Patients were evaluated for caries and fracture by two investigators at 7 and 26 months using the CDA quality evaluation criteria in additional to periodontal criteria. The results indicated a large number of excellent ratings for color and surface, but lower ratings for anatomic form and marginal integrity.

Bridges supported by free-standing implants versus bridges supported by tooth and implant. A five-year prospective study.

The clinical question at issue, whether it is possible to combine implants and natural teeth via fixed bridges, is of current interest. The treatment of the subjects of this prospective study was performed between June 1984 and December 1986. This article presents the 5-year results of the study. The consecutive patient material comprised 23 patients with Applegate Kennedy Class I residual dentition in the mandible and a complete maxillary denture. All 23 patients were provided with implants ad modum Brånemark in each mandibular quadrant. One side was randomized to rehabilitation with fixed bridge between the distal tooth of the residual dentition and an implant; the other side received a free-standang bridge on 2 implants. The fixture survival rate was 88%. No difference was found between the two sides. Bridge stability was 89% for the implant bridges and 91% for the combination bridges. The change in marginal bone level at the implants was small during the 5-year follow up period (on average 0.1-0.3 mm) and with no difference between the two sides. In conclusion, it was not possible to demonstrate any higher risk of implant or prosthetic failure for tooth-implant fixed bridges compared with implant-supported bridges.

Vertical load distribution on a three-unit prosthesis supported by a natural tooth and a single Brånemark implant. An in vivo study.

In vivo bite forces, implant axial forces and bending moments were measured on 5 patients with fixed posterior prostheses supported by a natural tooth and a single Brånemark implant. The results demonstrate that the vertical loads applied to the prostheses are shared between the tooth and the implant. The maximum bending moment transferred to the implant (10-15 N.cm) was well below the acceptable load limits for the mechanical components (50-60 N.cm), even at bite forces exceeding 100 N. The main reason for this load sharing seems to be the inherent bending flexibility of the implant screw joint, which matches the axial flexibility of the periodontal ligament of the tooth.

Bone grafts and implants in the treatment of the severely resorbed maxillae: a 3-year follow-up of the prosthetic restoration.

Thirty patients with severely resorbed maxillae were treated in a one-stage procedure using bone graft and implant placement. A horseshoe-shaped bone graft was taken from the iliac wing and fixed to the residual maxillary ridge using titanium implants, which supported the prostheses placed after a 6-month healing period. The material constituted two groups: a development group, the first 10 patients; and a routine group, the following 20 patients. At the 3-year follow-up, the implant survival was 87.5% and the prosthesis stability was 100% in the routine group. The probing depth did not change during the follow-up period, while the grafted region decreased in volume during the first postoperative year. The patients reported improved chewing ability and improved life quality. Very few technical and prosthodontic complications occurred.

Implant treatment in partially edentulous patients: a report on prostheses after 3 years.

There has been an increasing interest in the use of implants for partially edentulous patients. This introduces other biomechanical situations than those experienced in completely edentulous patients. In a prospective multicenter study, 521 implants in 154 patients were loaded with 197 free-standing prostheses. The patients have been followed for 3 years. The cumulative success rate for the prostheses was 94.8% and for the implants it was 93.9%. Most of the lost prostheses were only supported by two implants. A frequent technical complication was fracture and loosening of gold screws, which was more frequent in prostheses supported by only two implants.