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Purpose: Replacement of lost teeth has significant functional and psychosocial effects. The capability of osseointegrated dental implants to transmit a certain amount of sensibility is still unclear. The phenomenon of developing a certain amount of tactile sensibility through osseointegrated dental implants is called osseoperception. The aim of this article is to evaluate the available literature to find osseoperception associated with dental implants., Materials and Methods: To identify suitable literature, an electronic search was performed using Medline and PubMed database. Articles published in English and articles whose abstract is available in English were included. The articles included in the review were based on osseoperception, tactile sensation, and neurophysiological mechanoreceptors in relation to dental implants. Articles on peri-implantitis and infection-related sensitivity were not included. Review articles without the original data were excluded, although references to potentially pertinent articles were noted for further follow-up. The phenomenon of osseoperception remains a matter of debate, so the search strategy mainly focused on articles on osseoperception and tactile sensibility of dental implants. This review presents the histological, neurophysiological, and psychophysical evidence of osseoperception and also the role of mechanoreceptors in osseoperception., Results: The literature on osseoperception in dental implants is very scarce. The initial literature search resulted in 90 articles, of which 81 articles that fulfilled the inclusion criteria were included in this systematic review., Conclusion: Patients restored with implant-supported prostheses reported improved tactile and motor function when compared with patients wearing complete dentures., (© 2016 by the American College of Prosthodontists.)

Purpose: To determine the range of vertical cantilever (VC), real cantilever (RC), and height of the imaginary triangle (h) formed by the bases of the three implant cylinders in full-arch mandibular prostheses supported by three implants., Materials and Methods: The sample comprised 203 patients (147 women, 56 men; mean age, 58 years, range, 37 to 79 years) with full-arch mandibular rehabilitations. Their prostheses were measured in relation to implant placement to characterize numerical values for VC, force arm of the lever system (represented by the distal cantilever or RC), and resistance arm of the system (represented by the height of the imaginary triangle formed by the bases of the three implants). Data were tabulated and means and standard deviations calculated for all measurements. The range of each of the three measurements was then divided into quintiles for characterizing data distribution., Results: The mean (standard deviation) values found were as follows: VC1 = 17.11 (3.39) mm; VC2 = 17.46 (2.89) mm; VC3 = 16.68 (3.16) mm; RC1 = 14.67 (3.90) mm; RC3 = 15.02 (4.15) mm; h = 8.27 (2.96) mm., Conclusion: VC ranged from 7.37 to 26.44 mm, RC ranged from 4.00 to 26.93 mm, and the height of the imaginary triangle formed by the bases of the three implant cylinders ranged from 0.37 to 15.33 mm.

Background: Wound healing events after implant placement will vary according to the extent of the necrotic zone., Purpose: The goal of the present study was to evaluate bone healing around titanium implants with a novel apical chamber design., Materials and Methods: Titanium implants grade 4 were turned with different apex design. Control implants had a self tapping design with centric cutting grooves. Test implants exhibited eccentric cutting grooves interconnected by a hollow chamber. A total of 60 implants were installed in the femur/tibia of 10 rabbits for histological analysis., Results: After 1 week, immature bone formation started at the cortical level of the test implants associated to scalloped contours indicative of bone resorption. Control implants failed to show new bone formation, and the space within the threads was filled mainly by red blood cells and surgical debris. Bone contact values showed no difference after 1 week, and significant higher values for test implants showed likewise after 4 weeks compared with control implants in the tibia., Conclusion: This experimental study verifies the beneficial effect of bone formation in the chamber at the apical part of the fixture coupled to a faster bone healing to implants placed in dense bone., (© 2013 Wiley Periodicals, Inc.)

Purpose: Conventionally, in patients with completely edentulous mandibles, fixed prostheses have been supported by four or more implants. However, an alternative protocol employing three implants and immediate loading has been developed. The objective of the present study was to assess the rehabilitation of edentulous patients treated with a complete fixed mandibular prosthesis with immediate loading and supported by three implants., Materials and Methods: In this observational study, a total of 99 implants placed in 33 patients was evaluated after 18 months in use. Panoramic radiographs were digitized to measure bone loss at the mesial and distal surfaces of each implant., Results: Mean peri-implant bone loss was 0.66 ± 0.51 mm for the left implant, 0.92 ± 0.61 mm for the central implant, and 0.82 ± 0.53 mm for the right implant. The bone loss observed around the distal implants was similar to that seen around the central implant, and there were no statistically significant differences in peri-implant bone loss between the three implant locations. There was no significant correlation between implant length and bone loss. The results were compatible with the peri-implant bone loss that has been described for prostheses of the same type supported by larger numbers of implants., Conclusions: The use of a complete fixed mandibular prosthesis with immediate loading supported by three implants proved to be an adequate option for the rehabilitation of edentulous patients. The protocol allowed simplification of treatment while maintaining similar bone loss to that reported for the same type of treatment supported by a larger number of implants.

Background: The existing approaches to the treatment of the atrophic maxilla are difficult and involve an element of risk., Purpose: The aim of the present study was to establish a new surgical/prosthetic protocol for the treatment of extremely atrophic maxillae using four zygomatic implants (ZIs) in an immediate loading system., Materials and Methods: Twelve patients were treated with the surgical placement of 48 ZIs, and the totally edentulous maxillae were rehabilitated with protocol-type maxillary prostheses rigidly fixed to the ZIs in an immediate loading system. Follow-up was conducted at 6 months and again at 30 months., Results: Of the 48 ZIs inserted, one implant failed to achieve osseointegration. The prosthetic components fitted well and no sinus pathology was detected in any of the patients., Conclusion: The surgical/prosthetic protocol showed that it was possible to insert four ZIs in an immediate loading system and achieve stability for up to 30 months.

Purpose: The purpose of this clinical investigation was to evaluate the treatment outcome with zygoma implants with regard to implant survival, patient satisfaction, and function of prosthesis replacement after 3 years., Patients and Methods: The treatment outcome of 76 patients treated with 145 zygoma fixtures at 16 centers was evaluated with regard to implant survival. Status of peri-implant mucosa and amount of plaque were registered annually. Patients' and dentists' evaluations of the functional and esthetic outcome of the treatment were assessed at delivery of prosthesis and thereafter at each follow-up visit., Results: Sixty of 76 patients were followed for 3 years after prosthetic delivery. Five of 145 placed zygoma implants failed during the course of the study resulting in an overall implant survival rate of 96.3%. At the 3-year follow-up, 75% of the implants sites were registered with normal peri-implant mucosa and 68% with no visible plaque. The patients were fully satisfied with the esthetic and functional outcome of the treatment in 86% and 71%, respectively, at the 3-year follow-up visit. All reported data from dentists scored from acceptable to excellent., Conclusion: The multicenter study showed a high predictability of the zygoma implant-supported rehabilitation.

Five patients with rheumatoid arthritis or osteoarthrosis of the wrist joint were followed up for 15 (14-17) years after wrist-joint arthroplasty with semiconstrained artificial joint mechanisms that had been anchored to bone using the osseointegration principle. They were fixed by one titanium screw introduced into the radius, and two or more titanium screws introduced distally into the metacarpal bones. In four cases a screw was also introduced into the ulna thereby constituting one component in a distal radio-ulnar (DRU) joint mechanism. The titanium screw introduced into the radius and the distal metacarpal screws osseointegrated in all cases. In three cases the mechanism of the wrist joint or parts of it were replaced with new components that could be attached to the screws that were already osseointegrated. We conclude that wrist joint prostheses can be anchored to the surrounding bone using osseointegration and that they remain fixed for at least 15 years. The principle allows replacement of the joint mechanism, if needed, with maintenance of the osseointegrated anchoring elements.

Microvascular reactions to reduced flow in human skin as observed by vital microscopy are described. The behaviour of the cellular components of blood is analysed. Recirculation with only minor disturbances in the microcirculation was found even after complete occlusion for three hours. In one case occlusion of seven hours' duration was followed by recirculation. These findings indicate the integrity and restitution capability of the microvascular compartment in superficial human tissues at reduced flow.

Purpose: The aim of the present study was to evaluate zygomatic bone thickness considering a possible relationship between this parameter and cephalic index (CI) for better use of CI in the implant placement technique., Materials and Methods: CI was calculated for 60 dry Brazilian skulls. The zygomatic bones of the skulls were divided into 13 standardized sections for measurement. Bilateral measurements of zygomatic bone thickness were made on dry skulls., Results: Sections 5, 6, 8, and 9 were appropriate for implant anchorage in terms of location. The mean thicknesses of these sections were 6.05 mm for section 5, 3.15 mm for section 6, 6.13 mm for section 8, and 4.75 mm for section 9. In only 1 section, section 8, did mean thickness on 1 side of of the skull differ significantly from mean thickness on the other side (P <.001)., Discussion: For the relationship between quadrant thickness and CI, sections 6 and 8 varied independently of CI. Section 5 associated with brachycephaly, and section 9 associated with subbrachycephaly, presented variations in the corresponding thickness., Conclusion: Based on the results, implants should be placed in sections 5 and 8, since they presented the greatest thickness, except in brachycephalic subjects, where thickness was greatest in section 5, and in subbrachycephalic subjects, where thickness was greatest in section 9. CI did not prove to be an appropriate parameter for evaluating zygomatic bone thickness for this sampling. (More than 50 references.)

Purpose: To evaluate treatment outcome with Zygoma fixtures (Nobel Biocare, Göteborg, Sweden) with regard to fixture survival, patient satisfaction, and function of prosthesis replacement., Materials and Methods: The treatment outcome of 76 patients treated with 145 Zygoma fixtures at 16 centers was evaluated. Patient's and dentist's evaluations of the functional and aesthetic outcome of the treatment were assessed at delivery of prosthesis and at the 1-year follow-up visit. At the 1-year follow-up visit, the status of the peri-implant mucosa around the abutments and the amount of plaque were registered., Results: Sixty-six of the 76 patients, with 124 Zygoma fixtures supporting the prosthetic restorations, were evaluated at the 1-year follow-up. The overall survival rate for the Zygoma fixtures was 97.9% after 1-year of follow-up. Eighty percent of the patients were fully satisfied with both aesthetic and functional outcome at the time of prosthetic insertion and at the 1-year follow-up. All reported data from the dentists, with the exception of one restoration with several abutment screw loosenings, scored from acceptable to excellent for the aesthetic and functional outcome of the treatment. The status of peri-implant mucosa was recorded as normal in approximately 60% of the sites. Plaque, when present, was more often detected on the palatal surfaces compared with the buccal surfaces., Conclusion: This 1-year follow-up of Zygoma fixtures has shown good results with an acceptable number of minor complications and a majority of satisfied patients.

Despite refinements in surgical technique, including bone grafting and sophisticated prosthetic reconstructions, there are limitations to what can be achieved with bone-anchored fixed prostheses in patients with advanced atrophy of the maxillae. A new approach was suggested by a long-term study on onlay bone grafting and simultaneous placement of a fixture based on a new design: the zygoma fixture, and the aim of this study was to assess its potential. Twenty-eight consecutive patients with severely resorbed edentulous maxillae were included, 13 of whom had previously had multiple fixture surgery in the jawbone that had failed. A total of 52 zygoma fixtures and 106 conventional fixtures were installed. Bone grafting was deemed necessary in 17 patients. All patients have been followed for at least five years, and nine for up to 10 years. All patients were followed up with clinical and radiographic examinations, and in some cases rhinoscopy and sinoscopy as well. Three zygoma fixtures failed; two at the time of connection of the abutment and the third after six years. Of the conventional fixtures placed at the time of the zygoma fixture, 29 (27%) were lost. The overall prosthetic rehabilitation rate was 96% after at least five years of function. There were no signs of inflammatory reaction in the surrounding antral mucosa. Four patients with recurrent sinusitis recovered after inferior meatal antrostomy. To conclude, the zygoma fixture seems to be a valuable addition to our repertoire in the management of the compromised maxilla.

Background: The long-term predictability reported with the traditional two-staged Brånemark method has led to developments aimed at simplifying the technique and reducing healing time. Results from a pilot study using the Brånemark Novum concept are promising, and it has been shown possible to fabricate and deliver an implant-supported fixed prosthesis to the patient on the day of surgery., Purpose: The objective of this study is to report clinical and radiographic outcomes in a group of patients treated according to the Brånemark Novum concept., Materials and Methods: Ninety-five patients with edentulous mandibles were consecutively included in the study. Three specially designed fixtures were placed in each patient (285 fixtures in total) using drilling templates. The fixtures were immediately splinted with a prefabricated substructure, and fixed prostheses were delivered the same day in 67% of the patients. For the rest, prosthesis delivery ranged from 1 to 40 days (mean 5.6 d). Clinical and radiographic examinations were performed after 3 months, 6 months, 1 year, and then annually. The follow-up time was 1 to 5 years (mean 2.5 yr)., Results: The cumulative prosthesis survival rate was 99%. Eighteen fixtures (6.3%) failed in 13 patients. Kaplan-Meier survival estimates demonstrated a probability implant survival at 1 year of 95.0% (94 patients), at 3 years of 93.3% (47 patients), and at 5 years of 93.3% (9 patients). The mean bone loss was 0.73 mm between the examinations at 3 months and 1 year, 0.16 mm during the second year, and 0.13 mm annually during years 3 to 5., Conclusions: Comparable results, related to continuous prosthesis stability, were shown for the Novum approach compared with the traditional two-staged procedure. Survival of individual fixtures is lower when immediate loading is applied.

The psychological effects of tooth loss in the permanent dentition are relatively unknown. Complete edentulousness is a serious life event in terms of readjustment. The aim of the study was to describe the process patients with deteriorating dental status had gone through before treatment with a fixed prosthesis (Brånemark System, Novum), and to describe what living with a fixed prosthesis means to the patients themselves. In-depth interviews were carried out with 18 patients, and the interviews were transcribed verbatim and analysed in open, axial and selective coding processes according to Grounded Theory. In the analysis, four categories were developed and labelled: 'alterations in self-image', 'becoming a deviating person', 'becoming an uncertain person' and 'becoming the person I once was'. 'Alterations in self-image' was identified as the core category and was related to the other three categories. The core category describes the changes in self-image starting with the subjects' increasingly worsened dental status, followed by a period of them having to live and cope with a denture and, finally, their living with a fixed prosthesis. The motive power for the decision to undergo treatment with a fixed prosthesis seems to be a desire to restore dental status and also to recapture attractiveness, self-esteem and a positive self-image.

The rehabilitation of maxillary defects is a significant challenge in terms of creating retention and preserving existing dentition in an environment of expanded functional stress. The advent of osseointegration has enhanced the dental practitioner's capabilities in this regard with a remarkably improved potential for increasing prosthesis stability and preserving tissue. For patients with extensive prosthetic cantilevers, however, the opportunity for implant placement in defect areas is compromised unless remote bone sites are considered. Implants in the defect buttress zone through the maxillary sinus in non-defect sites (zygoma implants) can be valuable in providing a level of functional rehabilitation previously unattainable.

Seven men mean age 37 years (range 24-45) who had destroyed metacarpophalangeal joints as a result of pyogenic infection underwent reconstruction of the joint with osseointegrated silicone implants. The interval from infection to reconstruction varied from 5 months to 13 years. At mean follow-up 10 (8-12) years postoperatively the titanium fixtures were all well osseointegrated. The silicone spacer had fractured in one case. The extension lag was 16 (10-20) degrees and the range of movement (ROM) 34 (30-40) degrees. Our data confirm previous observations about the successful long-term osseointegration of titanium fixtures used for the attachment of joint prostheses in the hands of patients with rheumatoid arthritis or osteoarthritis. We conclude that titanium fixtures can be used successfully to fix joint mechanisms for reconstruction of small joints after pyogenous arthritis of the hand and can be used for fixation of joint mechanisms in such cases.

Purpose: The purpose of this report is to describe a new technique to fabricate and deliver an implant-supported fixed prosthesis to the patient on the day of surgery, and to propose a protocol for the prosthodontic and dental laboratory procedures., Materials and Methods: The development of the Brånemark Novum prosthodontic protocol is reviewed, and clinical and dental laboratory assessments and methods are described., Results: The total treatment time to fabricate a permanent implant-supported fixed prosthesis in the mandible can be reduced to 1 day with the Brånemark Novum technique. The new method includes a precise surgical technique using drilling templates for predetermined implant positions, a rigid splinting of the implants immediately after placement, the use of a prefabricated titanium framework, and elimination of implant impression procedures., Conclusion: With the technique described in this report, it is possible to provide patients with a permanent implant-supported fixed prosthesis in the mandible on the day of implant surgery. Patient benefits are obvious, with drastically reduced total treatment time, lower cost, and fewer clinical visits.

The technique of using osseointegrated bone-anchored percutaneous titanium implants in the rehabilitation of patients with amputated limbs has recently been introduced at the Brånemark Osseointegration Centre in Göteborg. The new method is based on an implantation technique that is well-established for anchorage of bone-conductive hearing aids and craniofacial prostheses. The soft tissues around skin-penetrating titanium implants used to anchor orthopaedic prostheses were evaluated histochemically using quantitative analyses. The implants had been in clinical use for between 6 to 24 months. The number of inflammatory cells was higher in the area close to the interface than in the area distant from the skin-penetrating site, and higher than in the corresponding controls. The current data was also compared with corresponding data from tissue around skin-penetrating craniofacial implants. The number of inflammatory cells was lower in the orthopaedic samples than in the craniofacial specimens. We conclude that skin-penetration of orthopaedic implants is as safe as when titanium implants are used for craniofacial rehabilitation, which is a clinically well-established procedure.

Osseointegrated proximal interphalangeal joint prostheses with a replaceable joint spacer were used in 25 joints in 19 patients (five men and 14 women) aged 45 (16-67) years. Indications for surgery were post-traumatic arthrosis (nine joints in eight patients), primary osteoarthrosis (10 joints in eight patients), and rheumatoid arthritis (six joints in three patients). A silicone joint spacer was attached to titanium fixtures by short titanium stems that extended from the spacer and fitted into a central canal in the screws. The arthroplasty was done in one stage, which included resection of the joint followed by grafting of marrow and cancellous bone from the iliac crest into adjacent medullary cavities before insertion of the titanium fixture. Follow up at 8.5 (5-11) years showed that 47 out of 50 fixtures (94%) had successfully osseointegrated while 17 of 25 joint spacers (68%) had fractured. However, because of the design of the prostheses fractured joint spacers could easily be replaced and a new spacer could be connected to already osseointegrated screws. The joint spacer was replaced in 11 fingers once or several times. Range of movement (ROM) in the whole series (four fusions excluded) was 41 (0-85) degrees with an extension defect of 15 (0-55) degrees. In eight joints with permanently intact joint spacers the ROM was 39 (0-60) degrees with extension defects of 16 (0-40) degrees. In six joints in which the spacer was replaced once the ROM was 43 (0-85) degrees with an extension defect of 16 (0-55) degrees. Our data confirm good long-term osseointegration of titanium fixtures and that a joint spacer, if needed, can be replaced by a new spacer that can be attached to already osseointegrated screws without jeopardizing the ROM.

Multinucleated giant cells have been observed at interfaces between bone marrow and titanium implants in mouse femurs. This raises concern that macrophage-derived factors might perturb local lymphohemopoiesis, possibly even predisposing to neoplasia in the B lymphocyte lineage. It has been found that an implant-marrow interface with associated giant cells persists for at least 1.5 years. Precursor B cells show early increases in number and proliferative activity. At later intervals, however, they do not differ significantly from controls, and there are no perturbations in spatial localization of either B lineage cells or DNA-synthesizing hemopoietic cells. The results of this investigation in mice demonstrate that, following initial marrow regeneration and fluctuating precursor B cell activity, and despite the presence of giant cells, titanium implants apparently become well-tolerated by directly apposed bone marrow cells in a lasting state of "myelointegration."

The present study evaluated implant survival and marginal bone loss in maxillae over a 15-year follow-up period as a function of either monocortical or bicortical implant anchorage. Of 207 standard Brånemark implants (10 mm in length) followed, 110 implants were judged to be monocortically anchored and 97 as bicortically anchored. The bicortically anchored implants failed nearly 4 times more often than the monocortical ones. Implant fractures accounted for over 80% of the observed failures and were found to affect the bicortical group almost 3 times more often. As tentative explanations, induction of increased stress and bending forces resulting from possible prosthetic misfit, presence of unfavorable arch relationships, or high occlusal tables in combination with bicortically anchored implants have been suggested, all indicating an overambitious fixation of the bicortical anchorage. Total marginal bone loss was low over the 15-year period and close to identical for the 2 groups, suggesting that the mode of cortical anchorage did not have any clinically significant influence on marginal bone remodeling.

Background: Oral implant treatment (Brånemark System) of edentulous mandibles has been presented in numerous studies. However, with regard to the severely atrophic lower jaw, no long-term follow-up studies with solely short implants are available., Purpose: The purpose of the present investigation was to retrospectively follow the long-term treatment outcome of patients with severely resorbed edentulous mandibles being subjected to oral implant placement with short (6-7 mm) Brånemark implants., Materials and Methods: A total of 247 standard (7 mm long, Ø 3.75 mm) and 13 wide (6 mm long, Ø 5 mm) implants were inserted in 49 patients, all of whom exhibited severe resorption of edentate mandibles. Fixed implant-supported prostheses were manufactured for 45 patients, whereas 4 patients received overdentures. The patients were followed for a mean period of 8 years (range, 1-14 yr)., Results: Seventeen implants failed during the study period (cumulative implant survival rate 95.5% at 5-yr and 92.3% at 10-yr follow-up). Implant-supported constructions were worn continuously throughout the investigation by all study subjects. Marginal bone loss, measured after 1, 5, and 10 years of function, concurred with studies of Brånemark implants placed in more voluminous mandibles. No major clinical or construction complications occurred in the followed patients., Conclusions: The outcome of the present study showed that placement of short Brånemark implants without the use of bone grafting procedures for reconstruction of severely atrophic edentulous mandibles is a highly predictable treatment procedure.

Damage to bone tissue due to heat shock is one of the main causes of the failure of osseointegration at the bone-implant interface. To investigate the effect of heat shock on regeneration of bone tissue, osteoblasts were exposed to heat shock for 10 minutes at 42, 45, or 48 degrees C or kept at 37 degrees C as a control. After 10 minutes of heat shock, disruption of actin filaments was seen in the cells and the degree of disruption increased with the temperature. The cytoskeleton reassembled after a 12-hour incubation at 37 degrees C in the cells treated at 42 or 45 degrees C, but this reversible recovery did not occur in the cells treated at 48 degrees C. Flow cytometric analysis showed that heat shock at 48 degrees C increased the number of necrotic cells to 15-20% within minutes (p < 0.05 compared with 37 degrees C). Apoptosis, evidenced by annexin V staining, DNA laddering, and caspase 3 activation, started after 6-8 hours of incubation, reached a peak at 12 hours, and gradually declined (p<0.05). Pretreatment with the antioxidant N-acetyl-L-cysteine reduced the necrosis induced at 48 degrees C of heat shock by one-half (p<0.05) but had no significant effect on caspase 3 activation induced by heat shock, suggesting that reactive oxygen species were critical in heat shock-induced necrosis but not in apoptosis. Heat shock at 48 degrees C induced a sustained translocation of p53 into the nucleus and a sustained activation of c-jun N-terminal kinase, whereas that at 42 and 45 degrees C induced only transient p53 translocation and c-jun N-terminal kinase activation. These results suggest that the sustained activation of p53 and c-jun N-terminal kinase pathways may contribute to heat shock-induced apoptosis. On the other hand, heat shock protein 70 increased dramatically in the cells treated at 45 or 48 degrees C, suggesting that the protecting mechanism in the cells was also activated. Such protection was able to prevent apoptosis in cells treated at 45 degrees C but not in those treated at 48 degrees C.

Purpose: The current investigation was undertaken to study whether osseointegration of implants in irradiated tissues is subject to a higher failure rate than in nonirradiated tissues. It further aimed to study whether hyperbaric oxygen treatment (HBO) can be used to reduce implant failure., Patients and Methods: Seventy-eight cancer patients who were rehabilitated using osseointegrated implants between 1981 and 1997 were investigated. Three groups of patients were compared: irradiated (A), nonirradiated (B), and irradiated and HBO-treated (C). In addition, 10 irradiated patients who had lost most of their implants received new ones after HBO treatment. These were compared as a case-control group., Results: Implant failures were highest in group A (53.7%). Implant failure was 13.5% in group B and 8.1% in group C. The difference between group A and the other two groups was statistically significant (P = .001 to .0023, Mantell's test). HBO significantly improved implant survival in the case-control group from 34 of 43 implants lost to 5 of 42 lost (P = .0078)., Conclusions: Implant insertion in irradiated bone is associated with a higher failure rate. Adjuvant HBO treatment can reduce the failures.

20 patients were operated on consecutively with osseointegrated MCP joint prostheses in 64 joints at our department between September 1993 and February 1995. The one-stage procedure included joint resection and cancellous bone grafting from the iliac crest before insertion of screw-shaped titanium fixtures, connected with a flexible silicone spacer. 18 patients (57 joints) were clinically and radiographically examined at median 28 (18-37) months postoperatively. Indications for surgery were joint destruction due to chronic arthritis in 17 patients (56 joints), and posttraumatic arthrosis in 1 patient (1 joint). Postoperative median range of motion was 40 (15-85) degrees, with an extension deficit of 30 (-20-70) degrees. 16 patients were satisfied, and had good pain relief and substantially improved postoperative hand function, evaluated with the standardized Sollerman hand function test. Radiographic osseointegration was obtained in 112 of 114 titanium fixtures (98%), but fracture of the silicone spacer was observed in 14 implants (25%). We conclude that osseointegration of longitudinal titanium fixtures in the bone marrow canal is possible in a one-stage procedure, but our findings show the need for a new, more durable joint spacer.

Osseointegrated endoprostheses were used in 22 proximal interphalangeal joint replacements in 12 patients between 1993 and 1995. Indications for surgery were joint destruction due to rheumatoid arthritis (13 joints), primary osteoarthrosis (7 joints), posttraumatic arthrosis (1 joint), and psoriatic arthritis (1 joint). The prostheses consisted of 2 screw-shaped titanium fixtures with a flexible silicone spacer. The 1-stage surgical procedure included joint resection and cancellous bone grafting from the iliac crest before insertion of the titanium fixtures. At a follow-up examination 27 months (range, 12-37 months) after surgery, the average active range of motion was 56 degrees (20 degrees to 80 degrees) with an extension lag of 11 degrees (-5 degrees to 45 degrees), corresponding to an average arc of motion of from 11 degrees to 67 degrees flexion. Radiographs indicated that 41 of 44 fixtures were osseointegrated. Four of the 22 joint mechanisms showed fracture of the silicone spacer; deformation of the silicone was noted in an additional 27%. Patient satisfaction was high (20 of 22 joints), with significantly improved range of motion and hand function, increased grip strength, good pain relief, and satisfactory appearance. The results of this study indicate good early clinical findings using osseointegrated implants for proximal interphalangeal joint replacement but also show the need for further development regarding the durability of the flexible silicone joint spacer.

Background: Brånemark fixtures were originally prescribed to be placed in two surgical stages. During the past years, reports on the placement of machined titanium implants in a one-stage procedure have been published, and the results have been encouraging. Recently there has been considerable interest in early or immediate loading., Purpose: The purpose of this article is to report the preliminary clinical results of a new method for implant treatment of the edentulous mandible. The new protocol involves prefabricated components and surgical guides, elimination of the prosthetic impression procedure and attachment of the permanent fixed bridge on the day of implant placement., Methods: Fifty patients (26 males, 24 females) received 150 Brånemark Novum implants and were followed from 6 months to 3 years after implant placement. Bone width and height were determined preoperatively with the use of radiographs. The jaw was reduced in height to accommodate three special 5-mm wide implants. Precise implant positioning was accomplished with special drilling templates. Drill guides were placed over the drilling templates during site preparation using a series of specially designed drills. After the mucosa had been sutured back into position, a prefabricated titanium lower bar was connected with titanium screws to the transmucosal fixture. Another titanium bar was then attached by the prosthodontist, and a bite registration was performed. The bridge was attached to the upper bar. The permanent reconstruction was provided to the patient later the same day., Results: Three implants were lost to follow-up and three failed, resulting in an overall survival rate of 98%. One prosthesis failed, leaving a prosthetic survival rate of 98%. The average treatment time was approximately 7 hours. At the baseline examination, the marginal bone level was 0.72 mm below the reference point. The average marginal bone loss was 0.2 mm per year and 0.26 mm between the 3-month and 1-year control visits. The accumulated mean bone loss, including baseline, was -1.25 mm. A patient questionnaire demonstrated that 94% of the patients did not experience any discomfort during treatment and all patients would recommend the procedure to others., Conclusion: The results of this study indicate that the precise surgical and prosthetic protocol allows successful prosthetic rehabilitation of mandibular edentulism and that the permanent reconstruction can be provided to the patient on the day of fixture surgery.

Purpose: The aim of this 5-year prospective study was to compare the results of single-tooth implant treatments planned and performed at four general practitioners' offices with the results from a specialist clinic., Materials and Methods: The group comprised 38 patients. Nineteen patients, with 19 implants/crowns, were planned and treated by four general practitioners, and the outcome was compared to a matched group of patients from a specialist clinic., Results: Three patients did not complete the study. None of the implants failed; one crown failed. This was a very positive result, as the single failure, a crown at the specialist clinic, was caused by an extraordinary trauma and was not related to a common cause such as bite forces or fatigue. No significant differences were observed between the groups when the radiographic findings were compared. Some minor differences, for bleeding and the position of the mucosal level around implants and adjacent teeth, were observed between the two groups., Conclusion: The small discrepancies that were observed between treatment performed by the four general practitioners at their own offices and treatment performed at the specialist clinic were not regarded to be of any clinical importance. This indicates that complete single-tooth implant treatment may be performed for many patients by general practitioners who have received adequate training, allowing the possibility of referring complicated treatments to specialists and other treatments to general practitioners.

Purpose: The aim of this prospective study was to present the results after 5 years of loading of 65 CeraOne (Nobel Biocare) crowns., Materials and Methods: Sixty-two implants in the maxilla and 3 implants in the mandible were placed in 57 patients. Sixty-two all-ceramic and three metal-ceramic crowns were cemented. The group comprised the first patients treated with the CeraOne prosthodontic concept., Results: Eight patients did not complete the study. Only one implant failed, giving a cumulative success rate for implants of 98.5%. The failed implant was replaced: a crown was cemented and then followed for 5 years without any complications. Four crowns were recorded as failures, giving a cumulative success rate for crowns of 93.7%. It should be observed that this result was very positive, as all crown failures were related to extraordinary causes and not one was a result of common bite forces or fatigue. The initial bone loss was in accordance with other studies on Brånemark implants, and a stable situation was recorded after 2 years for the supporting bone around implants and adjacent teeth when the conical implants were excluded. Soft tissues around implants and adjacent teeth appeared healthy, and the cementation and the placement of the abutment shoulder in the peri-implant sulcus did not cause any recession of the peri-implant mucosa., Conclusion: CeraOne experienced virtually no complications and proved to be a highly predictable and safe prosthodontic concept. CeraOne also eliminated problems with abutment screw loosening and created a platform for good esthetic results and satisfied patients.

This study reports the results of torsion tests, pull-out tests, and lateral loading tests on osseointegrated commercially pure titanium fixtures. The tests were performed in vivo on six beagle dogs. Three fixtures, each with a diameter of 3.7 mm, were installed bilaterally in the tibia of each animal. The mean maximal pull-out load was 1.55 kN (n = 4), the mean maximal lateral transverse load was 0.21 kN (n = 2), the mean maximal lateral axial load was 0.18 kN (n = 2), the mean breakpoint torque was 0.31 Nm (n = 3), and the mean maximal torque was 0.43 Nm (n = 3). The torsion test revealed an almost immediate plastic deformation of the interface between the implant and bone; this indicates that although the contact between the bone and the implant is close, there is no strong bond, at least not in shear. The major transfer of load from the implant to the surrounding bone tissue must therefore depend on the design of the implant. A histological evaluation with measurements of the amount of bone in contact with the fixtures was performed. By the use of the histological and mechanical data, it is possible to estimate shear stresses in bone tissue (pull-out test) and in the interface (torque test). The mean maximal shear stress in bone tissue in the pull-out tests was 100 MPa (n = 4); the mean shear stress in the interface was 4.3 MPa (n = 3) in the torsion tests at the breakpoint torque and was 6.0 MPa (n = 3) at the maximal torque. It was also possible to estimate the shear modulus of elasticity in the pull-out and torque tests. The mean shear modulus in pull-out was 119 MPa (n = 4), and the mean apparent shear modulus in torsion was 9 kPa (n = 3) for an assumed interface thickness of 100 nm and was 86 kPa (n = 3) for an assumed interface thickness of 1,000 nm.

The long-term success of Brånemark implants has been previously reported. The success rate of the same implants, when associated with autologous grafts, seemed much less predictable. In the present study it is demonstrated that when these implants are installed in conjunction with an autologous corticocancellous hip graft, either onlay or inlay, the cumulative success rate remains at 95% for individual implants in non-smokers. The short extracorporal time might be an explanation. On the other hand, the same approach in patients with congenital defects or who underwent radiotherapy is deceptive. The use of hyperbaric oxygen may dramatically improve these results.

In complex craniofacial reconstruction involving an implant-supported prosthesis, problems such as tumor recurrence may require additional surgical resection. The solution to such recurrence may be autogenous bone grafting or additional implant placement or both (after resection of the tumor) and revision of the prosthesis. Tumor recurrence was seen during an 11-year, 8-month follow-up of a 58-year-old woman who had had an extensive mid-face defect. The various treatments, including extraoral and intraoral prostheses, provided the patient with an acceptable quality of life without interruption in use of the prostheses.

Five patients with rheumatoid arthritis (age 28-60 years) underwent wrist joint arthroplasty with individually designed artificial joint mechanisms, anchored to bone using the osseointegration principle. We report on the result from a 4 to 6.5 year follow-up with special emphasis on the fixation of the prosthesis to bone. There was no bone resorption or loosening of screws. Osseointegration of the titanium screws occurred in all cases and persisted throughout the observation period, although scattered lytic zones could sometimes be seen around the screws. The clinical results were satisfactory with pain relief and maintenance of a functional range of movement. The principle has prospects for fixation of a wrist joint mechanism to bone, although the presently used joint mechanism requires further refinement.

Three patients with traumatic amputation of the thumb at the metacarpophalangeal joint level underwent a two-stage reconstruction aimed at fixation of a thumb prosthesis to the first metacarpal bone via an osseointegrated titanium fixture. The first stage included insertion of the fixture into the medullary cavity of the first metacarpal bone in combination with transplantation of cancellous bone from the iliac crest. After 3 months, when the fixture was firmly osseointegrated into the bone, a skin-penetrating abutment was placed on top of the fixture, the surrounding skin being thinned to the thickness of a split-skin graft to minimize relative mobility. A thumb prosthesis could then be firmly attached to this fixture. At follow-up examinations between 18 months and 3 years; postoperatively perfect osseointegration of the implant persisted. There were no skin problems. Some extent of tactile discrimination was achieved in the prosthesis hypothetically based on transfer of tactile stimuli to endosteal nerves in the bone via the titanium fixture.

A series of 156 consecutive fully edentulous patients were rehabilitated by means of fixed prostheses on either 4 or 6 screw-shaped titanium implants. This retrospective study calculated survival rates for both prostheses and individual implants. Only patients with a 10-year follow-up were considered. The implant lengths were 10 (90%) or 7 mm. They were all inserted after pretapping. In the mandible 13 and 59 prostheses were installed on respectively 4 and 6 implants. In the upper jaw the respective numbers were 14 and 70. Both groups (4 versus 6 implants) were age- and gender-matched. A reduced jaw bone volume was the major reason for limiting the number of implants to 4. Although a tendency existed for an increased failure rate in patients with only 4 implants, the survival rate for both individual implants and prostheses was the same in both groups at the end of the 10-year observation period. The present tendency of some clinicians to install as many implants as possible in full edentulism should be seriously questioned.

Twenty-four posterior mandibular segments in 18 patients were operated on placing implants after mobilisation of the neurovascular bundle. Two different surgical techniques, transposition and lateralization was used. The overall survival rate of fixtures was 92.1%. Performing lateralization resulted in 100% success, while transposition resulted in 80% stable fixtures in the involved segments. The mean time to full restoration of nerve function was 3.8 weeks after lateralization and 5.7 weeks after tranposing the nerve. Three patients exhibited persisting slight hyposthesia, but all, subjectively negligible disturbances in nerve function.

Both the surgical and the prosthodontic procedures will be performed by one and the same general practitioner (GP) for many implant patients, as access to specialists is limited or non-existent in a large number of places. However, treatment by GPs has not been documented to the same extent as treatment performed by specialists. This lack of knowledge was the reason for the present study, in which four GPs performed both the surgery and the prosthodontics on patients requiring single tooth implant replacements. The treatments were performed after an initial training of the GP and his/her dental assistant for 8 days. The treatments by the GPs exhibited clinical results corresponding to those achieved at a specialist clinic. The outcome indicates that complete single tooth implant treatments might be performed by GPs who have passed an initial training and demonstrated an interest in a close co-operation with specialists in oral surgery/periodontics and prosthodontics. Such a co-operation should be based on the distribution of complicated cases to the specialists and of non-complicated cases to the GPs.

This review summarizes some aspects of osseointegration. The principles, implant type and design, surgical technique, and results are reviewed. A large number of patients have been followed after intraoral reconstruction using osseointegrated implants. The success rates are 95 percent in the maxilla and 99 percent in the mandible. In craniofacial reconstruction, results vary from 98 percent success in the temporal area to as low as 48 percent in the radiated orbit. Some early experience with finger joint reconstruction, bone-anchored finger prostheses, and major amputations are reviewed.

The osseointegration concept has been used for fixation of 68 MP joint endoprostheses in 31 patients operated on at the Department of Hand Surgery, Malmö General Hospital during the period 1988-1992. The indications were rheumatoid arthritis (50 joints), primary osteoarthrosis (three joints), post-traumatic osteoarthrosis (three joints), post-traumatic osteoarthrosis (five joints), post-infectious osteoarthrosis (seven joints) and joint deformities secondary to spastic conditions (three joints). The average follow-up time was 2.5 years (6-54 months). The surgical procedure included resection of the joint followed by introduction of screw-shaped titanium fixtures into the bone marrow cavities of the metacarpal and the phalangeal base. Rheumatoid cases usually required grafting of cancellous bone and marrow from the iliac crest. At the same time a flexible constrained silicone spacer was connected to the titanium fixtures in such a way as to allow later replacement of the spacer if accessory. The average active range of motion (ROM) was 57 degrees in the rheumatoid cases and 50 degrees in all cases. Radiological and clinical osseointegration occurred in every case, and there were no clinical signs of loosening. In four cases (6%) there was a fracture of the joint mechanism. Patient satisfaction was high, with pain relief, increased range of motion, improved hand function and good cosmetic appearance.

Titanium implants in facial bones for retention of epitheses or dental bridges were used for reconstruction in cancer patients after tumor surgery. Even heavily irradiated bones could integrate the implants and bear the load from the epithesis. No major complications, such as wound infection, fistulation, or osteoradionecrosis, occurred after implant surgery. There was, however, an increased loss of implants with time after irradiation, especially in the orbital region. When hyperbaric oxygen was used as adjunctive treatment, implant losses were reduced.

A method has been developed to examine the relationships between titanium implants in bone and the immune and hemopoietic cell populations in the adjacent bone marrow; it involves the use of miniaturized implants in the diaphysis of mouse femurs. After surgical placement of the implants, mice were sacrificed and the femurs were either embedded directly in Epon for preparation of ground sections or were decalcified in EDTA, embedded in Epon, subjected to a fracture technique to remove the implant, and sectioned for light and electron microscopy. Scanning electron microscopy revealed that the surfaces of implants removed in this way were virtually free of tissue remnants. Ground sections showed bone in direct contact with the implant surface, providing the first evidence of osseointegration in mice. In addition, an extensive surface of the implant interfaced directly with regenerated bone marrow, a condition that persisted for at least 18 weeks. Some bone marrow cells forming an incomplete layer in contact with the titanium interface had morphologic characteristics of macrophages and giant multinucleated cells. The results demonstrated a long-term integration between titanium implants and cellular elements of bone marrow and provide an experimental model to examine the possible implications of this interaction on the processes of lymphopoiesis and hemopoiesis.