Showing papers on "Osseointegration published in 1994"

Vertical ridge augmentation using a membrane technique associated with osseointegrated implants.

Abstract: The purpose of this study was to evaluate: (1) the surgical protocol, effectiveness, and reliability for vertical ridge augmentation using a new titanium-reinforced membrane and osseointegrated implants; and (2) the histologic characteristics of the interface between a pure titanium implant and newly regenerated human bone. Five patients received 15 conical Branemark-type implants in six different surgical sites requiring vertical augmentation. The implants protruded 4 to 7 mm from the bone crest. Pure titanium miniscrews (1.3 x 10 mm) were positioned distally to the implants, protruding 3 to 4 mm from the bone level. The implants and the miniscrews were covered with a titanium-reinforced membrane, and the flaps were sutured. Membranes were removed at the stage 2 surgery after 9 months of healing. Measurements of biopsy specimens showed a gain in bone height from 3 to 4 mm. Histologic examination showed that all retrieved miniscrews were in direct contact with bone. Histomorphometric analysis of bone contact gave a mean value of 42.5 +/- 3.6% for five of the six examined miniscrews. The results suggest that the placement of implants protruding 3 to 4 mm from the top of resorbed bone surfaces may result in vertical bone regeneration to the top of the implant cylinder and that the regenerated bone is able to osseointegrate pure titanium implants.

The use of e-PTFE barrier membranes for bone promotion around titanium implants placed into extraction sockets: a prospective multicenter study

Abstract: This multicenter study was conducted to determine the predictability for implants placed into immediate extraction sockets and augmented with e-PTFE barrier membranes. Forty-nine implants were placed in immediate extraction sockets. Initial and final defect measurements and the number of threads exposed were compared. Patients were followed up to 1 year after implant loading. Three implants were lost at the abutment connection surgery. The 1-year survival rate was 93.9%. Twenty barrier membranes became exposed and were removed prior to stage 2 surgery, while the remaining barriers were removed at abutment connection. The average defect bone formation for membrane-retained sites was 4.8 mm, while the average bone formation for sites in which the membranes were prematurely removed was 4.0 mm (P < .0001). At stage 2 surgery there was an average of 0.6 threads exposed (P < .001) for the membrane-retained sites and 2.6 threads for the early removal sites (NS). Forty-five pairs of nonstandardized radiographs were evaluated for bone loss after implant loading (average 7.5 months). The mesiodistal bone loss averaged 0.72 mm. Within the limits of this study, e-PTFE membranes will promote clinically and statistically significant amounts of bone around immediately placed implants. Retention of e-PTFE barriers until stage 2 surgery improves the amount of bone promoted around the implants.

Peri-implant mucosal aspects of ITI implants supporting overdentures. A five-year longitudinal study.

Abstract: Sixty-six ITI implants placed in the mandible of 33 edentulous elderly patients (mean age: 69 years) were observed longitudinally for 5 years. The implants served as overdenture anchorage either by means of a connecting bar or single spherical attachments. During the study period, 2 implants failed (one because of a peri-implant lesion and one because of a fracture) and had to be removed. At the beginning of the study, all implants were osseointegrated and had successfully been in function for 335 months. Oral hygiene practices and the peri-implant mucosal status were assessed according to the criteria of conventional periodontal parameters. Approximately 50% of the implants had been installed into lining mucosa and hence were to surrounded by keratinized mucosa. The peri-implant mucosal tissue was maintained healthy during the whole observation period, and no or only minimal loss of attachment was observed. The probing depths averaged approximately 3 mm. At the end of the study, orthopantomographic radiographs were obtained from all patients to assess the peri-implant bony structures. Small local angular bony defects were detected on 16 implants (22%) in 12 patients. Slightly increased probing depths were observed when angular bony defects were present. Loss of attachment was significantly less frequent when the implants had been placed following a prolonged period of edentulousness (<5 years). This study demonstrated that advanced age, reduced dexterity of elderly patients and environmental conditions of overdentures do not represent a 1 higher risk for the development of peri-implant lesions.

Immediate implant surgery: three-year retrospective evaluation of 50 consecutive cases.

Abstract: Since August 1989, 35 consecutive patients were treated with immediate implants to replace 50 teeth requiring extractions as a result of root fractures, endodontic instability, nonrestorable carious lesions, or periodontal disease. Defects relative to the implant were morphologically grouped and were treated for bone regeneration with demineralized freeze-dried crushed cancellous bone (DFDBA), e-PTFE membrane, or both. Thread exposure initially ranged from 4 to 20 threads, while implant lengths varied from 8.5 to 18 mm. The mean implant length was 15 mm, with mean thread exposure of 11.34 threads, or 54% of the threaded length of the implant. Reentry confirmed 100% thread coverage in all but one implant in the no-wall group treated with DFDBA alone. Histologic evaluation of three cases confirmed viability of the regenerated bone. The patients were followed through April 1993, with 49 implants (98%) remaining osseointegrated and functional, supporting the predictability of immediate implant placement. The age of the patients ranged from 16 to 80 years, hence implant placement considerations relative to adolescents are also discussed.

Treatment planning and placement of implants in the posterior maxillae: report of 732 consecutive Nobelpharma implants.

Abstract: One to nine Nobelpharma osseointegrated implants were placed in the posterior maxillae of 213 consecutive partially edentulous patients. Reconstruction was completed with a ceramic fixed partial denture with follow-up of 5 to 70 months (mean 30.3 months) after loading. Thirty-four implants in 29 patients failed; eight were replaced and one of these failed. Thus, the overall failure rate was 4.8% (35/732). The failure rate in type IV bone was only slightly higher than that in types II and III bone (5.5% versus 4.6%). The failure rate in the entire molar area was 5.3% compared with 4.5% in the premolar area (P = NS), and the failure rate of 7-mm implants was 9.5% compared with 3.8% for implants of all other lengths (P = .01).

Clinical and radiographical features of submerged and nonsubmerged titanium implants.

Abstract: A clinical and radiographical study was performed to evaluate whether initial submergence of titanium fixtures is an obligate treatment measure for the establishment of proper bone anchorage when implants a.m. Branemark are used. The sample was comprised of 11 subjects with edentulous mandibles. A split-mouth design was employed; in the right mandibular quadrant a traditional 2-step procedure for fixture installation and abutment connection was utilized, while in the left quadrant a 1-step procedure was carried out, i.e., fixtures were placed and abutments were connected in one and the same session. Three to 4 months after fixture installation, fixed bridgeworks were fabricated and rigidly connected to the implants. Clinical examinations (including probing pocket depth, bleeding on probing and implant stability test) were performed after 12 and 18 months. Radiographs were taken following insertion of the bridges and at the 12- and 18-month re-examinations. The probing pocket depth, the bleeding on probing, the implant stability and the radiographic determinations were similar for the 2 groups of treatment alternatives. This indicates that titanium fixtures a.m. Branemark can be properly anchored (osseointegrated) in mandibular bone and successfully used for bridge retention also when a 1-step procedure is used for implant installation.

Vascularized bone flaps in oromandibular reconstruction. A comparative anatomic study of bone stock from various donor sites to assess suitability for enosseous dental implants.

Abstract: Objective: To identify donor sites from which vascularized bone may be harvested capable of accepting osseointegrated implants of the minimum dimensions required to ensure long-term implant stability. Design: An anatomic study of the most commonly employed donor sites for vascularized bone in oromandibular reconstruction was conducted on 28 cadavers. Setting: Academic tertiary referral center. Participants: Twenty-eight freshly embalmed, adult white cadavers (16 male, 12 female) were dissected. Intervention: The ipsilateral fibula, iliac crest, radius, and lateral border of the scapula were harvested and multiply sectioned at predetermined sites. Outcome Measure: Implantability was determined for each section based on measurements of height, width, and cross-sectional area utilizing computer planimetry. Results: The iliac crest was the most consistently implantable donor site, followed by the scapula, fibula, and radius (83%, 78%, 67%, and 21% of sections from each donor site satisfying the criteria for implantability). Consistent regional differences in implantability were encountered at each donor site except the scapula. Conclusions: Following ablation of oromandibular malignant neoplasms, restoration of stable retentive dentition is a prerequisite to a successful functional oral rehabilitation. This is best achieved with enosseous implants, capable of supporting a stable dental prosthesis, placed directly into vascularized bone flaps at the time of mandibular reconstruction. The implications of the results obtained in this study for gender, donor site selection, and orientation of the vascularized bone flap are discussed. (Arch Otolaryngol Head Neck Surg. 1994;120:36-43)

Bone Grafting and Guided Bone Regeneration for Immediate Dental Implants in Humans

Abstract: This study evaluated bone regeneration and osseointegration of hydroxyapatite (HA) coated and titanium plasma sprayed (TPS) implants placed in sockets immediately after extraction in 36 adults, mean age 55.2 years (range 26 to 81 years). Twelve TPS and 10 HA-coated implants in 20 patients were grafted with demineralized freeze-dried bone allograft (DFDBA), covered with a barrier material, and the facial flap coronally positioned to attain primary closure (experimental). The remaining 11 TPS and 10 HA-coated implants were placed similarly, except that no DFDBA was used (control). Osseous structures were measured at the initial placement and 6-month re-entry surgeries. At the 6-month re-entry, all implants placed were clinically osseointegrated. Bone resorption at the most coronal socket crest was -1.53 mm for the grafted group and -1.59 mm for the control group. Crestal bone apposition of 1.39 mm was noted at the most apical socket crest (ASC) for the grafted group, whereas crestal resorption of -0.11 mm was noted in the ungrafted control group (P < 0.02). Bone fill from the base of the deepest osseous defect was 5.68 mm for the grafted group and 3.18 mm for the control group (P < 0.04). Complete resolution of osseous defects occurred at 15 of 22 sites in the grafted group and at 9 of 21 sites in the control group. Clinical exposure of the barrier material and a subsequent inflammatory response at 27 of 43 sites, requires removal of the material prior to the 6-month re-entry and was associated with significantly more bone loss at the ASC sites (P < 0.01). There was no significant difference for any of the parameters when comparing the TPS with the HA-coated implants.

The influence of a hydroxyapatite and tricalcium-phosphate coating on bone growth into titanium fiber-metal implants.

Abstract: A study was done in rabbits to determine the effect of a hydroxyapatite and tricalcium-phosphate coating on bone growth into titanium fiber-metal implants. Titanium fiber rods with a solid titanium core were implanted bilaterally into the distal aspect of the femora of fifty-five New Zealand White rabbits. One rod was uncoated and the other rod was surface-coated with hydroxyapatite and tricalcium phosphate by the plasma-spray technique. Thirty-five rabbits were labeled sequentially with fluorochromes; killed at one, two, three, four, six, twelve, or twenty-four weeks after the operation; and studied histologically and histomorphometrically. The implants in the remaining twenty rabbits were subjected to pull-out testing to determine the shear strength at the implant-bone interface at three, six, twelve, and twenty-four weeks after the operation. Histomorphometry revealed significant effects of the hydroxyapatite and tricalcium-phosphate coating. When whole-group means (which included all time-points) were compared, it was found that 44 per cent of the perimeter of the hydroxyapatite and tricalcium-phosphate-coated implants was covered with bone compared with 12 per cent of the perimeter of the uncoated implants. The percentage of the internal surface of the implant that was covered with bone was also significantly higher in the hydroxyapatite and tricalcium-phosphate-coated implants: 27 per cent of the internal surface of the coated implants was covered compared with 8 per cent in the uncoated implants. The amount of bone in the pores of the implants was also higher in the hydroxyapatite and tricalcium-phosphate-coated implants: 12 per cent of the available pore space in the hydroxyapatite and tricalcium-phosphate-coated implants was filled with bone compared with 4 per cent in the uncoated implants. Scanning electron microscopy of the implants, done in backscatter mode, demonstrated apposition of new bone directly on the hydroxyapatite and tricalcium-phosphate coating, with variable degrees (amounts) of hydroxyapatite and tricalcium-phosphate resorption and new-bone replacement over time. Bone was never directly apposed to uncoated titanium fiber-metal. The pull-out strength of the hydroxyapatite and tricalcium-phosphate-coated implants was consistently greater than that of the uncoated implants, at all time-periods.

Prosthodontic complications in osseointegrated dental implant treatment.

Abstract: Complications were recorded in consecutive patients with osseointegrated implant-supported prostheses visiting prosthodontic specialist clinics during October and November 1991. Patients at regular follow-ups and emergency visits were included. Of the 600 prostheses examined, 28% needed some prosthodontic treatment. Complications varied widely--from simple adjustment to complete remaking of the prosthesis. The most common complications observed were related to the acrylic resin part of the prostheses. The frequency was higher in maxillary than in mandibular prostheses, and in full-arch removable and fixed prostheses than in single-tooth replacements and fixed partial dentures. Implant losses were rare (0.3% of all 2,709 implants placed) and occurred in 1% of the patients examined.

Fixed implant‐supported prostheses in the edentulous maxilla. A five‐year follow‐up report.

Abstract: Seventy-six patients were consecutively treated with fixed prostheses supported by osseointegrated implants in the edentulous maxilla and followed up for 5 years. The mean bone quality and resorption indices were 3.1 and 2.7 at the time of implant placement, respectively. Altogether, 449 standard Branemark implants were placed. Two patients resumed to complete dentures, and the cumulative implant and prosthesis survival rates were 92.1% and 95.9% for 5 years, respectively. The mean marginal bone level was 0.6 mm below the reference point at the time of placement and 1.2 mm below the same point 5 years later. Speech problems was the most frequent complaint during the first year of function, while resin fractures caused most adjustments during the follow-up period. No implant, abutment or gold alloy screws were found to be fractured, and only 4 patients had their prostheses re-tightened due to loose gold alloy screws.

Is osteoporosis a risk factor for osseointegration of dental implants

Abstract: The success of osseointegration depends in part on the state of the host bed. Concerns have therefore been raised about osteoporosis, a condition believed to be associated with a decrease in bone quality and quantity. However, the orthopedic literature indicates that osteoporotic fractures heal readily and that the level of bone mass and estimates of the parameters associated with bone remodeling present considerable overlap between patients with osteoporosis and control subjects. It also appears that osteoporosis, as diagnosed at one particular site of the skeleton, is not necessarily seen at another distant site. Although the prevalence of osteoporosis increases among the elderly and after menopause, the results of this study indicate that implant failure rate is not correlated with age and sex. A review of the literature and of results of a series of patients treated does not provide a compelling theoretical or practical basis to expect osteoporosis to be a risk factor for osseointegrated dental implants.

Morsellized allografts for fixation of the hip prosthesis femoral component: A mechanical and histological study in the goat

Abstract: To simulate femoral intramedullary bone stock loss in revision surgery of failed total hip arthroplasties, a method was developed using impacted trabecular bone grafts. In 14 goats a cemented total hip arthroplasty was performed, fixating the stem within a circumferential construction of bone allografts. After 6 or 12 weeks, 4 goats were used for mechanical tests and 3 for histology. The stability of the stems was determined in a loading experiment with roentgen-stereophotogrammetric analysis; loads of up to 1.44 times body weight were used. One aseptic loosening was seen with gross movements. In the other cases the most important movements were axial rotations (max. 0.24 degrees under 800 N) and axial translations (max. 0.16 mm under 800 N). After unloading some elastic recovery occurred. There were no differences between the 6 and 12-week groups. Histologically, revascularization and remodeling of the grafts were evident. Bone apposition and bone resorption of the grafts resulted in a mixture of graft and new bone. There was more new bone formation in the 12-week group, but the process was not yet completed. The use of impacted trabecular bone grafts in cases of severe intramedullary bone stock loss seems to be a promising revision technique.

The effects of micromotion and particulate materials on tissue differentiation: Bone chamber studies in rabbits

Abstract: Motion at the interface between bone and implants for joint replacement may interfere with osseointegration and prosthesis stabilization. Particulate materials may cause foreign body and chronic inflammatory reactions resulting in bone resorption (osteolysis). The micromotion chamber (MC) and the bone harvest chamber (BHC) were implanted in the rabbit tibia, and the effects of micromotion and phagocytosable particulate materials on tissue formation within the chamber were assessed by studying bone ingrowth into a 1-mm pore. Using the MC, one short daily episode of motion (20 cycles/day, 0.5 mm amplitude) for three weeks decreased the amount of bone ingrowth. Using a different pore configuration, the same parameters of motion increased bone ingrowth. Increasing the amplitude of motion (from 0.5 to 0.75 mm), or the number of daily motion periods (from one to two per day) then decreased bone ingrowth. These studies suggest the existence of a window of externally applied strain: a small stimulus may facilitate and a large stimulus may discourage bone formation within the chamber. Cessation of a given set of motion parameters (producing primarily fibrous tissue) for an additional three weeks was accompanied by tissue differentiation into bone. Using the BHC, small, phagocytosable particles of bone cement, high density polyethylene and cobalt chrome alloy, at a concentration of 1.0 x 10(8) particles/mL, caused a foreign body reaction and inhibited the ingrowth of bone. Particles of titanium alloy had no effect on net bone formation. In studies using normal and immunodeficient rats, T lymphocytes were not a prerequisite for macrophages to phagocytose polyethylene particles. In the clinical situation, micromotion and particulate debris may be synergistic in producing prosthetic loosening. If an implant does not undergo osseointegration due to excessive micromotion, the fibrous tissue interface may provide a conduit for the subsequent migration of particles around the implant.

Influence of metal implants on infection. An experimental study in rabbits

Abstract: We implanted cylinders of cobalt-chrome or titanium, with smooth or porous surfaces, into rabbit bones which had been inoculated with suspensions of Staphylococcus aureus in various doses. The bacterial concentration required to produce infection of porous-coated titanium implants was 2.5 times smaller than that necessary to infect implants with polished surfaces. Porous-coated cobalt-chromium implants required bacterial concentrations that were 40 times smaller than those needed to infect implants with polished surfaces, and 15 times smaller than those required to infect porous-coated titanium implants. The other advantages and disadvantages of the various implants, such as improved osseointegration, larger ion-release surfaces, surface wear and relative stiffness, must be weighed against the higher infection rates in the porous-coated implants, and particularly in the cobalt-chromium implants.

Maxillary implants and the growing patient.

Abstract: Maxillary skeletal and dental growth results in dramatic changes in all three dimensions during active growth. Experimental evidence and the behavior of ankylosed teeth suggest that an osseointegrated object remains stationary in the bone surrounding it and does not move or adapt to bone remodeling. Growth changes may result in the burying or loss of implants depending on the placement site. Hence, implants placed in the early mixed dentition have a poor prognosis of continued usefulness through puberty. When placed early, implants may disturb growth or have to be replaced. Implants placed during late puberty or early adulthood have the best change for long-term usefulness.

Membrane permeability is unnecessary for guided generation of new bone. An experimental study in the rabbit.

Abstract: The aim of this investigation was to test the hypothesis that membrane permeability is necessary in bone formation using the principle of guided tissue regeneration. On the forehead of 8 rabbits, titanium test cylinders were anchored in the calvaria. These cylinders were either covered by an expanded polytetrafluoroethylene (ePTFE) membrane generating a chamber for bone formation or they were sealed off by cast titanium. The implanted cylinders were covered by resuturing the periosteum and the cutaneous flap. After 8 months of healing, new bone had formed in all cylinders in all animals irrespective of whether the chamber for bone formation was sealed off by cast titanium or the ePTFE membrane. Based on these results, we conclude that permeability of the membrane is not necessary in the guided generation of new bone.

In vivo tensile testing of fluorapatite and hydroxylapatite plasma-sprayed coatings.

Abstract: A tensile test has been developed to test bioactive coating materials. Hydroxylapatite (HA) and fluorapatite (FA) coatings with various roughnesses were tested using sandblasted titanium (Ti) as a control material. Twelve goats received 7 implants each for 6 (2 goats), 12 (5), and 24 (4) week implantation periods. After 12 weeks the mean tensile strength values were highest for polished hydroxylapatite (HAP) followed by HA > FAP (polished fluorapatite) > FA > Ti, and hydroxylapatite type coatings were found to exhibit significantly higher values than fluorapatite type coatings or titanium implants. After 24 weeks no statistically significant differences could be found between any of the implant types. The order of the mean strength values was now HAP > HA > FA > FAP > Ti. Fracture always occurred between the coating and titanium if bone contact had been established. In conclusion, it is suggested that results from different types of test methods cannot be used to compare different types of bioactive coatings. © 1994 John Wiley & Sons, Inc.

Mandibular implants and the growing patient.

Abstract: The dynamic relation of the anteroposterior and rotational growth of the mandible to the transverse arch width and dental height changes must be understood before placing endosseous implants in actively growing patients. Research models demonstrate that osseointegrated implants lack the compensatory growth mechanism of the natural dentition. Remodeling associated with skeletal growth in the region of the implant placement site could cause the implant to either become unsupported by bone or submerged within it. Implants placed after age 15 in girls and 18 in boys have the most predictable prognosis. When placed in the growing patient, dental implants should be closely monitored and carefully restored with implant prostheses designed to accommodate growth and development.

Development of implant soft tissue emergence profile: A technique

Abstract: Despite successful osseointegration of dental implants, patients can be dissatisfied with the definitive restoration because of a poor esthetic result. An esthetic implant restoration depends on correct implant placement and a well-designed and fabricated prosthesis that includes the prosthetic teeth and the surrounding whether it is acrylic resin or soft tissue. This article describes a technique to help predict, develop, and evaluate implant prostheses and their soft tissue contours at the provisional restoration stage. This technique records the planned and subsequently proven contours, which are then used to guide fabrication of the final prosthesis and produce a predictable esthetic result.

Application of purified bone morphogenetic protein (BMP) in cranio-maxillo-facial surgery: BMP in compromised surgical reconstructions using titanium implants

Abstract: After a review of the clinically relevant literature on early modified whole bone products (demineralized bone; AAA bone (Urist et al., 1975))--predecessors of purified bone morphogenetic protein (BMP)--and a summary of the only published clinical experience with purified human BMP (in orthopedic surgery; from the group of Urist; Johnson et al., 1988-1992), an introductory overview of our experience with our own preparations of BMP from bovine bone in 271 procedures on the face and cranium in 145 patients is presented. In this first article of a series of three, major preprosthetic reconstructions using iliac bone grafts and titanium screw implants are described. All patients are examples of compromised bone and/or soft tissue conditions and cannot be considered routine indications for the operations performed. The most endangered implants became osseointegrated after 6 to 8 1/2 months as judged from clinical examination and CT imaging. These results demonstrate the efficacy of purified, concentrated BMP preparations, able unequivocally to induce bone even in areas with seemingly lost implants.

Mineral apposition rates of human cancellous bone at the interface of porous coated implants

Abstract: Human cancellous bone ingrowth studies were conducted on 19 consenting bilateral total knee arthroplasty (TKA) patients. Titanium porous coated cylinders were implanted into the medial femoral condyle of the contralateral knee during the first of two TKAs. Retrieval was performed at the time of the second TKA (6–131 weeks later), and fluorochrome analysis was conducted. Mean mineral apposition rates (MAR) at the interface measured 1.0 μm/day, whereas 4 mm away, the peripheral bone had a mean MAR of 0.8 μm/day. This represented a 25% acceleration in the interface bone remodeling rate when compared with the periphery (P < .05). This study showed the bone advanced appositionally at the interface at a rate of ≈ 1 μm/day. Analysis showed that when bone was over 50 μm from the porous coating, bone ingrowth did not occur. These results emphasize the need for surgical precision and careful postoperative management to achieve bone ingrowth. © 1994 John Wiley & Sons, Inc.

Qualitative and quantitative comparative study on different filling materials used in bone tissue regeneration: a controlled clinical study.

Abstract: This study compared, in a human model, the ability of (1) expanded polytetrafluorethylene (e-PTFE) membranes plus bone-chip autografts, (2) e-PTFE membranes plus demineralized freeze-dried bone, (3) e-PTFE membranes plus a new form of demineralized allograft bone tissue, and (4) e-PTFE membranes alone to enhance bone regeneration around dental implants placed into recent extraction sockets. The histologic results demonstrated that, in humans, guided tissue regeneration techniques are capable of producing new bone osseointegrated with titanium dental implants. Among the graft materials, autogenous bone provided the densest and the greatest amount of bone formation, but use of demineralized freeze-dried bone and a new form of de-mineralized allogenic bone matrix also improved bone regeneration compared to membranes alone after 6 months of healing.

Five-year statistical and clinical observations with the IMZ two-stage osteointegrated implant system.

Abstract: This study evaluated patients who were reconstructed with the IMZ system, which consists of a cylindrical implant with an intramobile element for stress relief. It is placed through a two-stage surgical procedure resulting in osteointegration. During a 5-year period, 1,059 implants were placed in 322 patients. Twenty-one implants were lost to follow-up. A total of 28 implants failed over the 5-year period, of which 9 had not integrated at stage 2 surgery. Of the remaining implants, 19 failed primarily for periodontal and prosthetic reasons. The life table method was used for statistical analysis. The 5-year survival rate of all IMZ implants was 95%. Seventy-five percent of the implants were placed to restore partial edentulism, with a survival rate of 96%. The survival rate for totally edentulous patients was also 96%. Forty-four percent of the implants were placed in the maxilla, with a survival rate of 92%. The survival rate in the mandible was 99%. Sixty-six percent of the implants were placed in women, with a survival rate of 94%. The survival rate in men was 98%. Major factors that positively influenced long-term survival were use of the longest and largest-diameter implants appropriate for the clinical situation.