			Home About us Contact

Implant Failure (implant + failure)

Distribution by Scientific Domains

Medical Sciences	93%
2 Other Domains	7%

Selected Abstracts

Cutting Torque Measurements in Conjunction with Implant Placement in Grafted and Nongrafted Maxillas as an Objective Evaluation of Bone Density: A Possible Method for Identifying Early Implant Failures?

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 1 2004
Björn Johansson DDS
ABSTRACT Background: Bone grafts are frequently used to enable the placement of dental implants in atrophied jaws. The biomechanical properties of bone grafts used in one- or two-stage implant procedures (in comparison with the use of nongrafted bone) are not well known. Purpose: The purpose of this study was (1) to measure cutting torques during the placement of self-tapping dental implants in nongrafted bone and in bone grafts, either as blocks or in a milled particulate form, in patients undergoing implant treatment in an edentulous maxilla and (2) to identify implants with reduced initial stability and to correlate these findings with a clinical classification of jawbone quality. Materials and Methods: The study included 40 consecutive patients with edentulous maxillas, 27 of whom were subjected to bone grafting prior to or in conjunction with implant placement (grafting group) and 13 of whom received implants without grafting (nongrafted group). Grafted bone from the iliac crest bone was used (1) as onlay blocks, (2) as maxillary sinus inlay blocks, or (3) in particulate form in the maxillary sinus. Implants were placed after 6 to 7 months of healing, except in the maxillary sinus inlay blocks, where implants were placed simultaneously. Cutting torque values were obtained from 113 grafted implant sites and from 109 nongrafted implant sites. Results: Significantly lower cutting torque values were assessed in grafted regions than in nongrafted regions, irrespective of grafting technique. Lower values were also seen for implants placed in block grafts after 6 months when compared to other grafting techniques used. The cutting torque values revealed an inverse linear relation to the Lekholm and Zarb bone quality index. Conclusion: The cutting torque values correlated well with the Lekholm and Zarb index of bone quality. Significantly lower cutting torque values were seen in grafted bone than in nongrafted bone. [source]

New insight into the mechanism of hip prosthesis loosening: Effect of titanium debris size on osteoblast function

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2004
Daniel T. O'Connor
Abstract The incidence of rheumatoid arthritis and osteoarthritis is on the rise due to our expanding elderly population. Total joint arthroplasty is the most successful, prevalent treatment modality for these and other degenerative hip conditions. Despite the wide array of prosthetic devices commercially available, hip prostheses share a common problem with a gradual and then accelerating loss of bone tissue and bone,implant interface integrity, followed by implant instability and loosening. Implant failure is largely the result of inevitable wear of the device and generation of wear debris. To provide information for the development of improved prosthetic wear characteristics, we examined the effects of size-separated titanium particles on bone forming cell populations. We demonstrate unequivocally that particle size is a critical factor in the function, proliferation, and viability of bone-forming osteoblasts in vitro. In addition, we have elucidated the time-dependent distribution of the phagocytosed particles within the osteoblast, indicating an accumulation of particles in the perinuclear area of the affected cells. The report finds that particle size is a critical factor in changes in the bone formation-related functions of osteoblasts exposed to simulate wear debris, and that 1.5,4 ,m titanium particles have the greatest effect on osteoblast proliferation and viability in vitro. The size of titanium particles generated through wear of a prosthetic device may be an important consideration in the development of superior implant technology. © 2003 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source]

An In Vivo Study of the Host Response to Starch-Based Polymers and Composites Subcutaneously Implanted in Rats

MACROMOLECULAR BIOSCIENCE, Issue 8 2005
Alexandra P. Marques
Abstract Summary: Implant failure is one of the major concerns in the biomaterials field. Several factors have been related to the fail but in general these biomaterials do not exhibit comparable physical, chemical or biological properties to natural tissues and ultimately, these devices can lead to chronic inflammation and foreign-body reactions. Starch-based biodegradable materials and composites have shown promising properties for a wide range of biomedical applications as well as a reduced capacity to elicit a strong reaction from immune system cells in vitro. In this work, blends of corn starch with ethylene vinyl alcohol (SEVA-C), cellulose acetate (SCA) and polycaprolactone (SPCL), as well as hydroxyapatite (HA) reinforced starch-based composites, were investigated in vivo. The aim of the work was to assess the host response evoked for starch-based biomaterials, identifying the presence of key cell types. The tissues surrounding the implant were harvested together with the material and processed histologically for evaluation using immunohistochemistry. At implant retrieval there was no cellular exudate around the implants and no macroscopic signs of an inflammatory reaction in any of the animals. The histological analysis of the sectioned interface tissue after immunohistochemical staining using ED1, ED2, CD54, MHC class II and ,/, antibodies showed positively stained cells for all antibodies, except for ,/, for all the implantation periods, where it was different for the various polymers and for the period of implantation. SPCL and SCA composites were the materials that stimulated the greatest cellular tissue responses, but generally biodegradable starch-based materials did not induce a severe reaction for the studied implantation times, which contrasts with other types of degradable polymeric biomaterials. [source]

Considerations for pacing of the cricoarytenoid dorsalis muscle by neuroprosthesis in horses

EQUINE VETERINARY JOURNAL, Issue 6 2010
N. G. DUCHARME
Summary Reasons for performing study: The success rate of prosthetic laryngoplasty is limited and may be associated with significant sequelae. Nerve muscle pedicle transplantation has been attempted but requires a year before function is restored. Objective: To determine the optimal parameters for functional electrical stimulation of the recurrent laryngeal nerve in horses. Methods: An experimental in vivo study was performed on 7 mature horses (2,21 years). A nerve cuff was placed on the distal end of the common trunk of the recurrent laryngeal nerve (RLN). In 6 horses the ipsilateral adductor branch of RLN was also transected. The electrodes were connected to programmable internal stimulator. Stimulation was performed using cathodic phase and then biphasic pulses at 24 Hz with a 0.427 ms pulse duration. Stimulation-response experiments were performed at monthly intervals, from one week following implantation. The study continued until unit failure or the end of project (12 months). Two of the horses were stimulated continuously for 60 min to assess onset of fatigue. Results: Excellent arytenoid cartilage abduction (mean arytenoid angle of 52.7°, range 48.5,56.2°) was obtained in 6 horses (laryngeal grades I or II (n = 3) and III (n = 2). Poor abduction was obtained in grade IV horses (n = 2). Arytenoid abduction was maintained for up to a year in one horse. Technical implant failure resulted in loss of abduction in 6 horses at one week to 11 months post operatively. Mean tissue impedance was 1.06 kOhm (range 0.64,1.67 kOhm) at one week, twice this value at 2 months (mean 2.32, range 1.11,3.75 kOhm) and was stable thereafter. Maximal abduction was achieved at a stimulation range of 0.65,7.2 mA. No electrical leakage was observed. Constant stimulation of the recurrent laryngeal nerve for 60 min led to full abduction without evidence of muscle fatigue. Conclusions: Functional electrical stimulation of the recurrent laryngeal nerve leading to full arytenoid abduction can be achieved. The minimal stimulation amplitude for maximal abduction angle is slightly higher than those for man and dogs. Clinical relevance: This treatment modality could eventually be applicable to horses with recurrent laryngeal neuropathy. [source]

Variation in the TNF Gene Promoter and Risk of Osteolysis After Total Hip Arthroplasty

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 11 2003
FRCS, J Mark Wilkinson PhD
Abstract Genetic factors may influence implant failure caused by osteolysis after THA. In an association study of 481 subjects after THA, we found that carriage of the TNF - 238A allele was associated with an increased incidence of osteolysis versus noncarriage (odds ratio, 1.7) and was independent of other risk factors. Genetic and environmental factors influence implant survival after THA. Introduction: Tumor necrosis factor (TNF) is thought to play a role in osteolysis, the major cause of implant failure after total hip arthroplasty (THA). Natural sequence variations at ,238 and ,308 in the TNF gene promoter are associated with differences in susceptibility to several TNF-mediated diseases. We tested whether these polymorphisms are associated with osteolysis after THA. Materials and Methods: A total of 481 whites (214 with failed versus 267 with intact implants) were recruited 11.7 ± 4 years after cemented THA. Genomic DNA was extracted from peripheral blood and genotyped for the ,238 and ,308 polymorphisms using the Taqman 5, nuclease method. Healthy controls (n = 500) from the background population were also genotyped to establish the local prevalence of these alleles. Results: The carriage of ,238A was 8.8% in the background population and 10.9% in the THA controls (p > 0.05). Carriage of ,238A in the osteolysis group was 17.3% (odds ratio, 1.7; 95% CI, 1.0,2.9). Carriage was highest (20.5%) in patients with more widespread osteolysis (OR, 2.1; 1.2,3.8). The association of ,238A with osteolysis was independent of other risk factors for osteolysis (logistic regression analysis: OR, 1.8; 1.0,3.2). Carriage of ,308A was not associated with osteolysis. Conclusion: Genetic, as well as environmental factors, influence implant failure after THA. Whether the TNF - 238 polymorphism causes a biological change that predisposes to loosening or is in linkage disequilibrium with such a locus is not yet known. [source]

Humoral immunity host factors in subjects with failing or successful titanium dental implants

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 12 2000
Mats Kronström
Abstract Background: Treatment with titanium dental implants is in general successful. However, an unknown number of implants do not integrate and are removed either by exfoliation or at the time of second stage surgery. It would be of importance to identify subjects at risk and predict early implant failure. Methods: In a retrospective study serum IgG antibody titers and avidity in sera from 40 subjects who had experienced titanium dental implant treatments with non-osseo-integration as the outcome (NOTI) and in sera from 40 age and gender matched control subjects who had received successful titanium dental implants (SOTI) were studied. Serum IgG titers to whole cell Actinomyces viscosus, Bacteroides forsythus, Porphyromonas gingivalis, Staphylococcus aureus, and Streptococcus intermedius sonicated antigen preparations were studied by ELISA. Results: Serum IgG antibody titers to S. aureus were significantly higher in subjects with SOTI than in NOTI (p<0.001) suggesting that higher titers indicate protection against implant failure as a result of S. aureus infection. Statistically significant higher serum IgG antibody avidity to P. gingivalis and B. forsythus were found in subjects with SOTI than in subjects with NOTI (p<0.01 and p<0.001, respectively). Statistical analysis failed to demonstrate antibody titer or avidity differences to the other pathogens studied. The likelihood that SOTI was associated with a high OD reading for S. aureus was 13.1:1 (p<0.001). Whether subjects were edentulous or not, or if they had lost teeth because of periodontitis or caries did not seem to matter. Conclusion: Serum IgG antibodies relative to B. forsythus, P. gingivalis and S. aureus may be associated with the outcome of implant procedures and explain why early implant failures occur. [source]

IMMEDIATE LOADING OF IMPLANTS IN THE ESTHETIC ZONE

JOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 5 2005
Saj Jivraj DDS
The predictability of dental implants using the traditional Branemark protocol has been well documented. Since its inception, this protocol has been progressively challenged to decrease treatment time, minimize the number of surgical procedures, and maximize esthetic outcomes. Today, in specific clinical situations, implants may be placed and immediately loaded with provisional restorations. Immediate loading in the edentulous mandible has been well documented. There are also good data to show that immediate loading of the edentulous maxilla is also feasible if bone quality is suitable. The focus now has shifted toward immediate loading of implants placed in the esthetic zone. Clinicians have recognized that the challenge of providing anterior tooth replacements is in preserving the hard and soft tissue components that exist around natural teeth. The advantages of immediate restoration are obvious; however, the application of immediate or early load may pose an increased risk of implant failure in single-tooth situations. The prerequisites for achieving and maintaining acceptable results are not fully known. This review examines some of the literature concerning the reliability of early or immediate loading of implants placed in the esthetic zone. [source]

Modeling Lipid Uptake in Expanded Polytetrafluoroethylene Vascular Prostheses and Its Effects on Mechanical Properties

ARTIFICIAL ORGANS, Issue 5 2000
Diego Mantovani
Abstract: The radial transport across the wall of expanded polytetrafluoroethylene (ePTFE) arterial prostheses has a significant effect on lipid uptake observed in prostheses implanted in humans, which has been postulated to be one of the causes associated with implant failure. The goal of this study was to stimulate radial transport on a lipidic dispersion across the wall of an ePTFE prosthesis and investigate its effects on the circumferential mechanical properties of the prosthesis. An in vitro model was developed to simulate the lipidic radial transport across the wall. Lipids contained in a phosphatidylcholine dispersion were used as the transported molecules. Lipid concentration profiles were obtained after exposing commercial ePTFE prostheses to various transmural pressure and/or lipidic concentration gradients. Phospholipids gradually accumulated up to the external reinforcing wrap of the prosthesis, which clearly acted as a rigid barrier against lipid infiltration. Tensile tests performed on the virgin samples showed that the wrap was much more rigid than the microporous part of the prosthesis. After the lipid simulation, the rigidity of the wrap decreased with respect to what was observed for the virgin prosthesis. Finally, some clinical implications of this phenomena are discussed. [source]

Outcomes of dental implants placed in a surgical training programme

AUSTRALIAN DENTAL JOURNAL, Issue 4 2009
LP Smith
Abstract Background:, This study evaluates surgical outcomes and survival rates of implants placed in a multidisciplinary implant teaching programme. Methods:, A retrospective review of all implant surgery performed over a 6-year period by accredited oral and maxillofacial surgery trainees at the Royal Dental Hospital of Melbourne was undertaken. Patients were reviewed for a minimum of 6 months post-implant placement. Implant survival was defined as those implants which were not removed, were clinically integrated as assessed by torque testing and in an appropriate position to receive a subsequent prosthesis. Kaplan-Meier analysis was used to assess overall survival and univariate factors affecting survival. Multivariate analysis used Cox proportional hazards models. Results:, Over 6 years, 127 patients were treated. Follow-up data were present for 105 patients with 236 implants placed. Survival of implants at 1 and 5 years was 94 per cent and 92.8 per cent, respectively. The only univariate and multivariate factor which affected implant survival was perioperative bone grafting. All failed implants were single stage. Other factors such as patient age, smoking status, implant site, anaesthetic type, immediate or delayed placement, implant length and diameter, and medical comorbidities did not significantly affect implant survival. Conclusions:, A satisfactory implant survival rate was found in a tertiary teaching centre. Perioperative bone grafting significantly increased the risk of implant failure. [source]

Clinical and Microbiological Determinants of Ailing Dental Implants

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 1 2009
Giorgio Tabanella DDS
ABSTRACT Background: The failure of the host tissue to establish or maintain osseointegration around dental implants is due to either occlusal or parafunctional forces, premature loading, ill-directed stress, or microbial infection. The long-term failure rate of dental implants is generally 5,10%. Although a variety of etiologies of early peri-implant bone loss (from implant placement to 1-year post-loading) have been proposed, factors associated with late implant failures are less well understood but are probably related to both the peri-implant microbial environment and host factors. Discriminating between causes of implant failure is of importance for instituting a successful implant therapy. Purpose: The objective of this cross-sectional split-mouth study was to identify clinical, radiographic, and bacterial characteristics of peri-implant disease sites. Materials and Methods: Fifteen patients with bilateral implants (Brånemark®, Nobel Biocare AB, Göteborg, Sweden; and 3iÔ implant systems, Implant Innovations Inc., Palm Beach Gardens, FL, USA) participated in the study. Sites with peri-implantitis (radiographic bone loss beyond the third implant thread) and peri-implant healthy tissues (radiographic bone level above the first implant thread) were identified in periapical radiographs using a long-cone paralleling projection technique. Microbiological identification was carried out using established anaerobic culture techniques. A descriptive statistics based on means and standard deviations was reported. Results: Peri-implant bone loss was associated with the absence of radiographic crestal lamina dura, peri-implant pocket depth, pain on chewing, and the submucosal presence of the putative periodontopathogens Tannerella forsythia, Campylobacter species, and Peptostreptococcus micros. Pain was associated with P. micros, Fusobacterium species, and Eubacterium species. Discussion and Conclusion: The absence of radiographic crestal lamina dura and the presence of suspected major periodontal pathogens seem to be associated to peri-implantitis. [source]

Immediate Loading of Two Implants Supporting a Ball Attachment-Retained Mandibular Overdenture: A Prospective Clinical Study

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 3 2007
Riccardo Marzola DDS
ABSTRACT Background:, A prospective clinical study was conducted to evaluate clinically and radiographically the performance of two implants immediately loaded supporting a ball attachment-retained mandibular overdenture. Materials and Methods:, Seventeen completely edentulous patients were included in the study. Each patient received two implants inserted after a minimal flap reflection and no vestibular extension in order to reduce the postoperative swelling and facilitate immediate prosthesis connection. After implant placement, a mandibular complete denture was connected to the implants using ball attachments of appropriate height according to the depth of the peri-implant tissue. Patients were asked not to remove the denture for 1 week. No limitations to chewing function were given. At implant placement, the maximum value of insertion torque was recorded. Patients were examined at 1, 2, 4, 12, and 52 weeks postsurgery. At postoperative visit, occlusion was checked and the need for any prosthesis maintenance was recorded. The radiographic bone level (RBL) change was measured on periapical radiographs at baseline and 12 months after loading. Results:, After 12 months of loading, no implant failure was reported and the survival rate was 100%. Average RBL change was 0.7 mm ± 0.5 mm. Of the 17 cases, two had major prosthetic complications and five patients required minor extra maintenance appointments. Conclusions:, The immediate loading of two implants by means of ball attachment-retained mandibular complete denture may be a predictable treatment option. This clinical approach offers increased stability and comfort, while keeping a high implant success rate. [source]

A Study on Variances in Multivariate Analyses of Oral Implant Outcome

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 1 2007
Irene Herrmann LDS, Odont Lic
ABSTRACT Background:, Elaborate studies have shown that interdependency exists between implants being placed in the same patient/jaw. Therefore, interdependency ought to be an important aspect to address, whenever performing statistical analyses of oral implant outcomes. A Jackknife method could be an option when conducting statistical evaluations of oral implant failure prognoses. Purpose:, The aim of this study was to evaluate whether a statistical difference can be detected by using the Jackknife method in conjunction with life table analyses and/or a log rank test of four different combinations of jaw density and quantity. Materials and Methods:, Four multicenter studies were pooled and adjusted in order to create a research database consisting of 486 patients and 1,737 implants in preparation for the Jackknife resampling method. Combinations of jaw shapes and bone qualities were constructed to select at-risk patients. Statistical Methods:, Life tables with confidence intervals were calculated and a log rank test was used to determine whether a statistical difference between the combinations could be established. Results:, Both statistical analyses, after the Jackknife resampling method, showed that patients with poor bone quality and resorbed jaws (combination IV) had a statistically higher risk of implant failure. Conclusion:, By rearranging data using the Jackknife method, standardized statistical tests seem to work well even when the study population tested was affected by interdependency. [source]

Early Complete Failures of Fixed Implant-Supported Prostheses in the Edentulous Maxilla: A 3-Year Analysis of 17 Consecutive Cluster Failure Patients

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2006
Odont Dr/PhD, Torsten Jemt DDS
ABSTRACT Background, Clusters of implant failures in the edentulous maxilla seem to occur in some patients. To create groups for analysis with higher numbers of these patients implies large original groups for inclusion. Purpose, The aim of this study was to retrospectively describe and compare a group of "cluster failure patients" with randomly selected patients treated in the edentulous maxilla. Materials and Methods, From a group of 1,267 consecutively treated patients in one clinic, all patients presenting failing fixed implant-supported prostheses within the first 3 years of follow-up were included. All patients were treated with turned titanium implants using two-stage surgery. A control group of equal number of patients were created for comparison. Data on patients were retrospectively retrieved from their records, and compared. Results, Seventeen patients (1.3%) met the inclusion criteria in the entire group. The bone resorption index revealed less bone quantity in the study group (p < .05) during implant placement, but there was no difference regarding primary implant stability at first-stage surgery. The distribution of short and long implants showed relatively higher number of short implants in the study group (p < .05), and more patients had a presurgical discussion on the risk of implant failure prior to treatment in this group (p < .05). Only 5 out of 102 implants (4.9%) were lost before prosthesis placement as compared to 38 and 25 lost implants during the following two years in the study group. Smoking habits and signs of bone loss related to periodontitis in the lower dentition were more frequent in the study group, but did not reach a significant level (p > .05). Conclusion, The results indicate that bone quantity, reflected in fixture length, has a significant impact on increased implant failure risk. Other factors of interest as predictors for implant failures could be smoking habits and also possibly signs of periodontitis in the opposing dentition. [source]

Fixed Mandibular Restorations on Three Early-Loaded Regular Platform Brånemark Implants

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 4 2001
Hugo De Bruyn DDS
ABSTRACT Background: Originally, the Brånemark System was used as a two-stage surgical procedure. Comparable clinical results have made one-stage and early-loading concepts possible alternatives in the edentulous mandible. From the patient's point of view, the financial aspect of implant treatment is important. In an attempt to decrease financial burden, the reduction of surgical interventions and reduction of the number of implants could be considered. Purpose: This prospective multicenter study evaluated (1) the 1-and 3-year success rates of implants loaded within 1 month after one-stage surgery with a fixed 10- to 12-unit bridge on three regular platform Brånemark System implants in the mandible, (2) the outcome of the prosthetic treatment, and (3) the opinion of patients regarding the treatment procedure. Materials and Methods: Of 20 patients, 19 received five implants in the mandible, of which three were functionally loaded with the one-stage technique (group 1). The loaded implants were inserted in a tripodal position, one implant in the symphysis and two located anterior of the mental foramen in the bicuspid area. Two additional implants were inserted for safety reasons but were not intended to be included in the restoration. These two additional implants served as either an unloaded one-stage control implant (group 2) or an unloaded control implant installed with the submerged technique (group 3). Immediately after surgery, the implants were loaded with a relined denture. The patients received a 10- to 12-unit prosthetic reconstruction an average 31 days (range, 4-53 d) after surgery. Implant stability was clinically checked at 3, 12, and 36 months. Radiographs were taken at corresponding follow-up visits to calculate bone-to-implant level and marginal bone resorption. Results: Six of 60 functionally loaded implants (10%) and 3 of 20 prostheses (15%) failed within the first year. The cumulative implant failure rate in group 1, both after 1 and after 3 years, was 9.5%. No implant failure occurred in the control groups 2 and 3. The average marginal bone level measured at 1 and 3 years was 1.6 mm (SD = 0.8 mm) and 2.1 mm (SD = 0.2 mm), respectively, for group 1; 1.5 mm (SD = 1.3 mm) and 2.4 mm (SD = 0.6 mm), respectively, for group 2; 0.8 mm (SD = 1.4 mm) and 0.7 mm (SD = 0.9 mm), respectively, for group 3. Conclusions: The results of treatment using three regular platform Brånemark System implants supporting a fixed mandibular arch reconstruction were less favorable than the outcome that can be expected with a standard four- to six-implant with one-stage surgery. [source]

Titanium allergy in dental implant patients: a clinical study on 1500 consecutive patients

CLINICAL ORAL IMPLANTS RESEARCH, Issue 8 2008
Alberto Sicilia
Abstract Background: In dentistry, allergic reactions to Ti implants have not been studied, nor considered by professionals. Placing permanent metal dental implants in allergic patients can provoke type IV or I reactions. Several symptoms have been described, from skin rashes and implant failure, to non-specific immune suppression. Objective: Our objective was to evaluate the presence of titanium allergy by the anamnesis and examination of patients, together with the selective use of cutaneous and epicutaneous testing, in patients treated with or intending to receive dental implants of such material. Material and methods: Thirty-five subjects out of 1500 implant patients treated and/or examined (2002,2004) were selected for Ti allergy analysis. Sixteen presented allergic symptoms after implant placement or unexplained implant failures [allergy compatible response group (ACRG)], while 19 had a history of other allergies, or were heavily Ti exposed during implant surgeries or had explained implant failures [predisposing factors group (PFG)]. Thirty-five controls were randomly selected (CG) in the Allergy Centre. Cutaneous and epicutaneous tests were carried out. Results: Nine out of the 1500 patients displayed positive (+) reactions to Ti allergy tests (0.6%): eight in the ACRG (50%), one in the PFG (5.3%)(P=0.009) and zero in the control group. Five positives were unexplained implant failures (five out of eight). Conclusions: Ti allergy can be detected in dental implant patients, even though its estimated prevalence is low (0.6%). A significantly higher risk of positive allergic reaction was found in patients showing post-op allergy compatible response (ACRG), in which cases allergy tests could be recommended. [source]

Impact of IL-1 genotype and smoking status on the prognosis of osseointegrated implants

CLINICAL ORAL IMPLANTS RESEARCH, Issue 4 2004
Boris Gruica
Abstract Aim: This study evaluated the impact of the IL-1 genotype and smoking status on the prognosis and development of complications of osseointegrated implants. Material and methods: The clinical charts of 180 consecutively admitted patients were analyzed with respect to the occurrence of biological complications in conjunction with oral implants. Biologic complications were defined as clinical conditions with suppuration from the peri-implant sulcus, development of a fistula or peri-implantitis with radiologic bone loss. All patients had received one or more ITI® dental implants, which had been in function for at least 8 (range: 8,15) years. This patient population had received 292 implants. From these, 51 implants in 34 patients showed late (infectious) biologic complications, and 241 implants had survived without any biologic complications at all. Results: Of the 180 patients, 53 were smokers, who were subdivided in a series of classes according to their intensity of smoking and 127 were never smokers. Sixty-four of 180 (36%) patients tested positive for the IL-1 genotype polymorphism. This prevalence corresponds to previous reports for the prevalence of European descent populations. The results for the non-smoking group indicated no significant correlation between implant complications and a positive IL-1 genotype. However, there was a clear association for heavy smokers between a positive IL-1 genotype and implant complications. 6 of 12 or half of the heavy smokers and IL-1 genotype-positive patients had either an implant failure, i.e. loss of implant, or a biologic complication during the follow-up period. Conclusions: These findings have led to the conclusion that there is a synergistic effect between a positive IL-1 genotype and smoking that puts dental implants at a significantly higher risk of developing biologic complications during function. Résumé Le but de cette étude a été d'évaluer l'impact du génotype IL-1 du tabagisme sur le pronostic et le développement de complication des implants buccaux ostéoïntégrés. Les dossiers cliniques de 180 patients ont été analysés en ce qui concerne l'arrivée de complications biologiques en association avec les implants buccaux. Des complications biologiques étaient définies en tant que conditions cliniques avec suppuration depuis le sillon paroïmplantaire, le développement d'une fistule ou d'une paroïmplantite avec perte osseuse radiologique. Tous les patients avait reçu un ou plusieurs implants buccaux ITI qui avaient été en fonction pour au moins huit années (de 8 à 15 ans). Les patients avaient reçu 292 implants. Parmi ceux-ci 51 chez 34 patients ont montré des complications biologiques tardives (infectieuses) et 241 avaient survécu sans aucune complication biologique. Des 180 patients, 53 étaient fumeurs qui ont été divisés en une série de classes suivant l'intensité du tabagisme tandis que 127 étaient non-fumeurs. Soixante-quatre des 180 patients (36%) ont été testés positifs pour le polymorphisme du génotype IL-1. Cette fréquence globale correspond au rapport précédent pour la fréquence globale des populations européennes. Les résultats pour le groupe non-fumeur indiquait qu'il n'y avait aucune relation significative entre les complications implantaires et un génotype IL-1 positif. Cependant, il y avait une association évidente pour les gros fumeurs entre le génotype IL-1 positif et des complications implantaires. Six des douze soit la moitié des gros fumeurs et des patients au génotype IL-1 positif avaient soit un échec implantaire (c.-à-d. la perte de l'implant) soit une complication biologique durant le suivi. Ces résultats ont conduit à la conclusion qu'il y a un effet synergétique entre le génotype IL-1 positif et le tabagisme mettant les implants buccaux à un risque beaucoup plus important à développer des complications biologiques durant leur mise en fonction. Zusammenfassung Ziel: Diese Studie untersuchte den Einfluss des IL-1 Genotyps und der Rauchgewohnheiten auf die Prognose und auf die Entwicklung von Komplikationen bei osseointegrierten Implantaten. Material und Methoden: Die Krankengeschichten von 180 aufgenommenen Patienten wurden auf biologische Komplikationen in Zusammenhang mit Zahni Implantaten untersucht. Biologische Komplikationen wurden definiert als klinische Zustände mit Suppuration aus dem periimplantären Sulcus, Entwicklung einer Fistel oder Periimplantitis mit radiologischem Knochenverlust. Alle Patienten waren mit einem oder mehreren ITI® Implantaten versorgt worden, welche für mindestens 8 Jahre (Bandbreite: 8,15 Jahre) in Funktion standen. Diese Patientenpopulation war mit 292 Implantaten versorgt worden. Von diesen 292 Implantaten zeigten 51 Implantate bei 34 Patienten biologische (infektiöse) komplikationen und 241 Implantate hatten ohne biologische Komplikationen überlebt. Resultate: Von den 180 Patienten waren 53 Raucher, welche in Untergruppen gemäss Schweregrad des Rauchens aufgeteilt wurden und 127 waren Nicht-Raucher. 64 der 180 Patienten (36%) zeigten ein positives Testergebnis bezüglich IL-1 Genotyp Polymorphismus. Diese Prävalenz entspricht früheren Berichten über die Prävalenz bei einer Population europäischer Abstammung. Die Resultate der Nicht-Raucher Gruppe zeigten keine signifikanten Korrelationen zwischen Implantatkomplikationen und einem positiven IL-1 Genotyp. Jedoch bestand bei den starken Rauchern eine klare Assoziation zwischen dem positiven IL-1 Genotyp und Implantatkomplikationen. 6 von 12 oder die Hälfte der starken Raucher und IL-1 Genotyp positiven Patienten zeigten entweder einen Implantat Misserfolg, z.B. Verlust des Implantats, oder eine biologische Komplikation während der Beobachtungsperiode. Schlussfolgerung: Die Ergebnisse haben zur Schlussfolgerung geführt, dass ein synergistischer Effekt zwischen einem IL-1 positiven Genotyp und Rauchen besteht, welcher Zahni Implantate einem signifikant höheren Risiko für die Entwicklung von biologischen Misserfolgen während der Funktion aussetzt. Resumen Intención: Este estudio evaluó el impacto del genotipo IL-1 y el estatus de fumador en el pronóstico y desarrollo de complicaciones de implantes orales osteointegrados. Material y métodos: Se analizaron las historias clínicas de 180 pacientes admitidos consecutivamente en lo referente a la ocurrencia de complicaciones biológicas en conjunción implantes orales. Se definieron las complicaciones orales como condiciones clínicas con supuración del surco periimplantario, desarrollo de una fístula o de periimplantitis con pérdida radiológica de hueso. Todos los pacientes recibieron uno o mas implantes orales ITI®, que levaban al menos 8 (rango 8,15) años en función. Esta población de pacientes recibió 292 implantes orales. De estos, 51 implantes de 34 pacientes mostraron (infecciones) complicaciones biológicas tardías, y 241 implantes sobrevivieron sin ninguna complicación biológica. Resultados: De los 180 pacientes, 53 eran fumadores que se subdividieron en una serie de categorías de acuerdo con su intensidad de consumo de tabaco y 127 nunca fueron fumadores. 64 de 180 (36%) dieron positivo al test del polimorfismo genético de la IL-1. Esta prevalencia corresponde con informes previos de prevalencia en poblaciones de origen europeo. Los resultados para el grupo de los no fumadores no indicó relación significativa entre complicaciones de los implantes y genotipo IL-1 positivo. Sin embargo, hubo una asociación clara para los fumadores intensos entre complicaciones de los implantes y un genotipo IL-1 positivo. 6 de 12 o la mitad de los fumadores intensos y los pacientes genotipo IL-1 positivo tuvieron o fracaso del implante i.e. pérdida del implante o una complicación biológica durante el periodo de seguimiento. Conclusiones: Estos hallazgos nos han conducido a la conclusión de que hay un efecto sinérgico entre genotipo IL-1 positivo y tabaquismo que colocan a los implantes orales en un riesgo significativamente mas alto para desarrollar complicaciones biológicas durante la función. [source]

Biomechanical aspects of marginal bone resorption around osseointegrated implants: considerations based on a three-dimensional finite element analysis

CLINICAL ORAL IMPLANTS RESEARCH, Issue 4 2004
Eriko Kitamura
Abstract Objectives: Although bone loss around implants is reported as a complication when it progresses uncontrolled, resorption does not always lead to implant loss, but may be the result of biomechanical adaptation to stress. To verify this hypothesis, a three-dimensional finite element analysis was performed and the influence of marginal bone resorption amount and shape on stress in the bone and implant was investigated. Material and methods: A total of nine bone models with an implant were created: a non-resorption (Base) model and eight variations, in which three different resorption depths were combined with pure vertical or conical (vertical,horizontal) resorption. Axial and buccolingual forces were applied independently to the occlusal node at the center of the superstructure. Results: Regardless of load direction, bone stresses were higher in the pure vertical resorption (A) models than in the Base model, and increased with resorption depth. However, cortical bone stress was much lower in the conical resorption models than in both the Base and A models of the same resorption depth. An opposite tendency was observed in the cancellous bone under buccolingual load. Under buccolingual load, highest stress in the implant increased linearly with the resorption depth for all the models and its location approached the void existing below the abutment screw. Conclusions: The results of this analysis suggest that a certain amount of conical resorption may be the result of biomechanical adaptation of bone to stress. However, as bone resorption progresses, the increasing stresses in the cancellous bone and implant under lateral load may result in implant failure. Résumé Bien que la perte osseuse autour des implants soit considérée comme une complication quand elle progresse de manière incontrôlée, la résoption ne se termine pas toujours par la perte de l'implant, mais peut être le résultat de l'adaptation biomécanique au stress. Pour vérifier cette hypothèse, une analyse d'éléments finis en trois dimensions a été effectuée et l'influence de l'aspect et de la quantité de résorption osseuse marginale au stress dans l'os et l'implant a été analysée. Neuf modèles osseux avec un implant ont été créés : un modèle (Base) sans résorption et huit variations dans lesquelles trois profondeurs de résorption différentes ont été combinées avec des résorptions verticales ou coniques (verticale-horizontale). Des forces axiales et vestibulo-linguales ont été appliquées de manière indépendante en occlusal au centre de la superstructure. Quelle que soit la direction de la charge, les stress osseux étaient plus importants dans la résorption verticale pure (A) que dans le modèle de base et augmentaient avec la profondeur de résorption. Cependant, le stress osseux cortical était beaucoup plus faible dans les modèles à résorption conique que dans les modèles Base et A de même profondeur de résorption. Une tendance opposée était observée dans l'os spongieux sous charge vestibulo-linguale. Sous charge vestibulo-linguale, le stress le plus important dans l'implant augmentait linéairement avec la profondeur de résorption pour tous les modèles et sa localisation approchait l'espace existant en-dessous du pilier. Les résultats de cette analyse suggèrent qu'une certaine quantité de résorption conique pourrait être le résultat d'une adaptation biomécanique au stress osseux. Cependant, quand la résorption osseuse progresse les stress s'amplifiant dans l'os spongieux et au niveau de l'implant sous une force latérale peuvent résulter en un échec implantaire. Zusammenfassung Ziel: Auch wenn ein Knochenverlust um Implantate, der unkontrolliert fortschreitet, als Komplikation beschrieben wird, führen solche Resorptionen nicht gezwungenermassen zu einem Implantatverlust. Sie könnten aber Ausdruck einer biomechanischen Adaptation auf die Belastungen sein. Um diese Hypothese zu überprüfen, führte man eine dreidimensionale "Finite-Element"-Analyse durch. Man untersuchte die Zusammenhänge von Ausmass und Form der marginalen Knochenresorption und den entstehenden Kräften im Knochen und Implantat. Material und Methode: Die Arbeitsgrundlage waren 9 Modelle mit je einem Implantat: eines diente als Kontrolle (ohne Resorptionserscheinungen), die anderen acht zeigten drei verschiedene Resortionstiefen in Kombination mit rein vertikalen oder konischen (vertiko-horizontal) Defektformen. Dann liess man, unabhängig von der Okklusionsgestaltung, axiale und buccolinguale Kräfte auf die Mitte der Suprastruktur auftreffen. Resultate: Unabhängig von der Belastungsrichtung war die Knochenbelastung bei den rein vertikalen Resorptionsmodellen (A) grösser als beim Kontrollmodell und sie nahmen mit der Tiefe der Resorption zu. Die Belastung im kortikalen Knochen war aber in den Modellen mit konischen Resorptionen viel geringer als beim Kontrollmodell und den A-Modellen mit denselben Resorptionstiefen. Eine genau umgekehrte Tendenz konnte man im spongiösen Knochen unter buccolingualer Belastung feststellen.Bei einer buccolingualen Belastung nahm die Belastungsspitze beim Implantat bei allen Modellen linear mit der Resorptionstiefe zu und der Ort dieser Belastungsspitze lag im Bereich des Leerraumes genau unterhalb der Schraube des Sekundärteils. Zusammenfassung: Die Resultate dieser Analyse lassen vermuten, dass die konische Resorption bis zu einem gewissen Ausmass das Resultat einer biomechanischen Adaptation auf die Belastung des Knochens ist. Wenn aber die Knochenresorption fortschreitet, können die zunehmenden Belastungen im spongiösen Knochen und im Implantat bei einer lateralen Belastung zum Implantatmisserfolg führen. Resumen Objetivos: Aunque la pérdida de hueso alrededor de los implantes se informa como una complicación cuando progresa incontroladamente, la reabsorción no siempre lleva a la pérdida del implante, pero puede ser el resultado de la adaptación biomecánica al estrés. Para verificar esta hipótesis, se llevó a cabo un análisis tridimensional de elementos finitos y se investigó la influencia de la cantidad de reabsorción de hueso marginal y la forma en el estrés en el hueso y el implante. Material y métodos: Se crearon un total de 9 modelos de hueso con un implante: Un modelo sin reabsorción (Base) y 8 variaciones, el las que se combinaron tres diferentes profundidades de reabsorción con reabsorciones verticales o cónicas puras (vertical,horizontal). Se aplicaron fuerzas axiales y bucolinguales independientemente al nodo oclusal en el centro de la superestructura. Resultados: A pesar de la dirección de la carga, los estreses óseos fueron más altos en los modelos de reabsorción vertical pura (A) que en los modelos Base y se incrementaron con la profundidad de reabsorción. De todos modos, el estrés cortical fue mucho menor en los modelos de reabsorción cónica que en los modelos Base y A con la misma profundidad de reabsorción. Se observó una tendencia opuesta en el hueso esponjoso bajo carga bucolingual. Bajo carga bucolingual, el estrés mas alto en el implante se incrementó linealmente con la profundidad de reabsorción para todos los modelos y su localización se aproximó al espacio existente bajo el tornillo del pilar. Conclusión: Los resultados de este análisis sugieren que cierta cantidad de reabsorción cónica puede resultar de la adaptación biomecánica del hueso al estrés. De todos modos, al progresar la reabsorción ósea, los estrés crecientes en el hueso esponjoso y en el implante bajo carga lateral puede resultar en un fracaso del implante. [source]

Representative marketing-oriented study on implants in the Austrian population.

CLINICAL ORAL IMPLANTS RESEARCH, Issue 5 2003

Abstract: The number of dental implants inserted annually worldwide has been estimated to come close to a million. But the level of information available to patients about realistic, evidence-based treatment options by implants is often enough more than fragmentary, and what is disseminated by the media and the industry does not always reflect evidence-based empirical data. This survey of 1000 adults presented with 18 questions was designed to shed light on several points. These were (1) level of subjective patient information, (2) sources of information and prejudices, (3) future demand for implant treatment and target groups for patient information campaigns, and (4) potential misinformation, information deficits, discrepancies of information and how these come about. Of those questioned, 20% said unprompted that implants were a possibility to replace missing teeth. When prompted, 72% said that they knew about dental implants. Most of those questioned felt poorly informed about the options for replacing missing teeth and many knew less about implants than about other alternatives. The dentist was said to be the desired source of information, but 77% of those questioned reported that their dentists did not practice implant dentistry. More than 79% of those questioned did not know whether their dentist worked with implants. Forty-four percent thought that implants should only be placed by specially trained doctors. Sixty-one percent were of the opinion that dentists who provide implant dentistry were better qualified than their nonimplanting colleagues. Half of those questioned attributed implant failures to allergies and incompatibilities, the other half to poor medical care. Only 29% incriminated poor oral hygiene as a cause of implant failure. Future strategies should be geared to more professional public relations and patient information. Internationally operating qualified implant institutions could contribute much to balance discrepant information. Résumé Le nombre d'implants dentaires insérés annuellement dans le monde se chiffrerait à environ un million. Mais le niveau d'information disponible du patient en ce qui concerne les options de traitement basées sur l'évidence est souvent fragmentaire, et l'information dispensée par les média et l'industrie ne reflète pas toujours ces options. Cette enquête réalisée sur mille adultes ayant reçu un questionnaire de 18 questions a été effectuée afin de mettre en évidence certains points. Ces derniers étaient 1) le niveau de l'information subjective du patient, 2) les sources d'information et préjudices, 3) la demande future pour le traitement implantaire et les groupes cibles pour les campagnes d'information des patients, 4) les mauvaises informations potentielles, les déficits d'information, les désaccords de l'information et les causes de ces derniers. De ces personnes questionnées, 20% ont répondu spontanément que les implants étaient un moyen de remplacer les dents manquantes. Lorsqu'ils étaient interrogés, 72% ont répondu connaître les implants dentaires. La plupart de ces personnes se sentaient cependant peu informées sur les options de remplacement des dents manquantes et beaucoup d'entre-elles possédaient très peu d'information sur les implants par rapport aux autres possibilités existantes. Le dentiste semblait être la source préférentielle d'information mais 77 % des personnes questionnées ont rapporté que leur dentiste ne plaçait pas d'implant. Plus de 79% ne savaient pas si leur dentiste pratiquait l'implantologie. Quarante-quatre pour cent étaient persuadés que les implants ne pouvaient être placés que par des spécialistes. Soixante et un pour cent pensaient que les dentistes pratiquant de la dentisterie implantaire étaient plus qualifiés que les autres collègues. La moitié attribuait les échecs implantaires aux allergies et aux incompatiblités, l'autre moitié aux mauvais soins médicaux. Seul 29% incriminaient la mauvaise hygiène buccale comme une cause d'échec implantaire. Des stratégies futures devraient être orientées vers davantage de relations publiques professionnelles et d'informations du patient. Des institutions d'implants internationales pourraient grandement contribuer à changer cette mauvaise information. Zusammenfassung Eine repräsentative marketing-orientierte Studie über Implantate in der Bevölkerung von Oesterreich. Teil I: Stand der Information, Informationsquellen und Bedürfnis bezüglich Patienteninformation Die Anzahl weltweit gesetzter Implantate pro Jahr wird auf fast eine Million geschätzt. Aber die den Patienten zur Verfügung stehende Information über realistische, auf Evidenz basierende Behandlungsmöglichkeiten mit Implantaten ist mehr als lückenhaft. Was durch die Medien und durch die Industrie verbreitet wird, wiederspiegelt nicht immer auf Evidenz basierende empirische Daten. Diese Untersuchung an 1000 Erwachsenen, welchen 18 Fragen gestellt wurden, wurde entwickelt, um Licht auf verschiedene Punkte zu werfen. Die Punkte betrafen (1) Stand der subjektiven Patienteninformation; (2) Informationsquellen und Vorurteile; (3) zukünftiger Bedarf an Implantatbehandlungen und Zielgruppen für Propaganda zur Patienteninformation; (4) potentielle Fehlinformation, Informationsdefizite, Diskrepanzen in der Information und wie diese zustande kommen. Von den gefragten Individuen sagten ohne Vorinformation 20%, dass Implantate eine Varainte für den Ersatz von fehlenden Zähnen darstellen. Mit Vorinformation sagten 72%, dass sie von dentalen Implantaten Kenntnis haben. Die meisten der Befragten fühlten sich über die Möglichkeiten bezüglich Ersatz fehlender Zähne schlecht informiert und viele wussten weniger über Implantate als über andere Behandlungsvarianten. Es wurde gesagt, der Zahnarzt sei die gewünschte Informationsquelle, aber 77% der Befragten berichteten, dass ihr Zahnarzt keine Behandlungen mit Implantaten anbietet. Mehr als 79% der Befragten wussten nicht, ob ihr Zahnarzt mit Implantaten arbeitet. Vierundvierzig Prozent dachten, dass Implantate nur durch speziell ausgebildete Aerzte gesetzt werden sollten. Einundsechzig Prozent waren der Meinung, dass Zahnärzte, welche Implantatbehandlungen anbieten, besser qualifiziert sind als ihre nicht-implantierenden Kollegen. Die Hälfte der Befragten führten Implantatmisserfolge auf Allergien und Unverträglichkeiten zurück, die andere Hälfte auf schlechte medizinische Nachsorge. Nur 29% bezeichneten eine schlechte Mundhygiene als Ursache für Implantatmisserfolge. Zukünftige Studien sollten Richtung professioneller Publikums- und Patienteninformation gesteuert werden. International tätige qualifizierte Implantatinstitutionen könnten beträchtlich zum Ausgleich von widersprüchlichen Informationen beitragen. Resumen El número de implantes dentales insertados anualmente en todo el mundo se ha estimado cercano al millón. Pero el nivel de información disponible para los pacientes acerca de opciones de tratamiento reales con implantes basados en la evidencia es frecuentemente mas bien fragmentaria y lo que se disemina por los medios y la industria no siempre refleja los datos empíricos basados en la evidencia. Esta encuesta de 1000 adultos que presentaba 18 preguntas fue diseñada para dar luz en determinados puntos. Estos fueron (1) nivel subjetivo de información de los pacientes; (2) fuentes de información y prejuicios; (3) demanda futura para tratamiento de implantes y grupos diana para campañas de información; (4) desinformación potencial, déficit de información, discrepancias de información y como se generan. De aquellos a los que se preguntó, 20% dijeron espontáneamente que los implantes eran una posibilidad para reemplazar dientes ausentes. Cuando se les preguntó, 72% dijeron que sabían acerca de los implantes dentales. La mayoría de los encuestados se sentían pobremente informados acerca de las opciones para reemplazar dientes ausentes y muchos sabían menos acerca de los implantes que sobre otras alternativas. Se dijo que el dentista era la fuente de información mas deseada, pero 77% de los encuestados manifestó que sus dentistas no practicaban implantología. Mas del 79% de los encuestados no sabían si su dentista trabajaba con implantes. El 44% pensaba que los implantes debían ponerse solamente por doctores especialmente entrenados. El 61% eran de la opinión de que los dentistas que realizaban odontología de implantes estaban mejor cualificados que sus colegas que no lo hacían. La mitad de los encuestados atribuían los fracasos de los implantes a alergias e incompatibilidades, la otra mitad a pobres cuidados médicos. Solo el 29% incriminó a la pobre higiene oral como causa de fracaso de los implantes. La futura estrategia debe ser encaminada a unas relaciones públicas más profesionales y a más información del paciente. Las instituciones de implantes cualificadas que operan internacionalmente podrían contribuir a equilibrar la información discrepante. [source]

Implants placed in combination with an internal sinus lift without graft material: an analysis of short-term failure

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2009
Olaf Gabbert
Abstract Aim: Investigation of the short-term survival of implants placed in combination with an internal sinus lift (ISL) without graft material. Material and Methods: Thirty-six patients received 92 screw-shaped dental implants in combination with an ISL. No bone grafts or bone substitutes were used. Forty-four patients with 77 implants in the native posterior maxilla served as controls. X-rays taken after implant placement and 6 months later were evaluated for the presence of bone gain at the apical aspect of the implants. Kaplan,Meier survival curves and Cox regression analysis were used to estimate survival curves and to isolate risk factors for implant failures. Results: Within a mean observation period of 1.2 years (minimum 9 months; maximum 3.7 years), four failures were recorded in the experimental group and two in the controls. The probability of survival was above 94% for both groups. Six,nine months after surgery, bone gain was observed in 29 out of 92 implants. Comparison of the experimental group and controls revealed no effect of ISL and membrane perforation on the probability of survival. Conclusions: Promising short-term outcomes were observed for implants with ISL without graft material; for a substantial proportion of implants, apical bone gain was observed in the first 6,9 months. [source]

Humoral immunity host factors in subjects with failing or successful titanium dental implants

Immediate Maxillary Lateral Incisor Implants with Nonocclusal Loading Provisional Crowns

JOURNAL OF PROSTHODONTICS, Issue 1 2008
Miguel Peñarrocha MD
Abstract This clinical report series describes a treatment modality involving immediately placed dental implants in maxillary lateral incisor sites using noncemented immediate provisional crowns retained with calcinable copings (prosthetic complement used in preparing the metal for the definitive prosthesis). Ten implants were placed in eight patients for the replacement of maxillary lateral incisors: two immediate and eight corresponding to cases of agenesis. All were subjected to immediate rehabilitation with provisional acrylic resin crowns in nonocclusal loading. One implant failed 3 weeks after placement due to acute local trauma. The other nine remained functional within the mouth, with normal clinical and radiological characteristics after a minimum of 12-month follow-up. Immediate placement of implant fixed provisional restorations retained by friction in maxillary lateral incisors offers an esthetic solution, eliminates the need for a removable provisional restoration, and avoids implant failures associated with excess cement or screw loosening. Moreover, in the case of extractions, immediate placement and provisionalization of implants in maxillary lateral incisors can effectively optimize the peri-implant esthetic results by maintaining the existing hard and soft tissue architecture of the replaced tooth. As no cement or screws are required, and the provisional crowns are placed in nonocclusal loading, the risk of complications is minimized. [source]

Two-Year Outcome with Nobel Direct® Implants: A Retrospective Radiographic and Microbiologic Study in 10 Patients

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 3 2009
Tommie Van de Velde LA
ABSTRACT Introduction: The Nobel Direct® implant (Nobel Biocare AB, Göteborg, Sweden) was developed to minimize marginal bone resorption and to result in "soft tissue integration" for an optimized aesthetic outcome. However, conflicting results have been presented in the literature. The aim of this present study was to evaluate the clinical and microbiologic outcomes of Nobel Direct implants. Materials and Methods: Ten partially edentulous subjects without evidence of active periodontitis (mean age 55 years) received 12 Nobel Direct implants. Implants were loaded with single crowns after a healing period of 3 to 6 months. Treatment outcomes were assessed at month 24. Routine clinical assessments, intraoral radiographs, and microbiologic samplings were made. Histologic analysis of one failing implant and chemical spectroscopy around three unused implants was performed. Paired Wilcoxon signed-rank test was used for the evaluation of bone loss; otherwise, descriptive analysis was performed. Results: Implants were functionally loaded after 3 to 6 months. At 2 years, the mean bone loss of remaining implants was 2.0 mm (SD ± 1.1 mm; range: 0.0,3.4 mm). Three out of 12 implants with an early mean bone loss >3 mm were lost. The surviving implants showed increasing bone loss between 6 and 24 months (p = .028). Only 3 out of the 12 implants were considered successful and showed bone loss of <1.7 mm after 2 years. High rates of pathogens, including Aggregatibacter actinomycetemcomitans, Fusobacterium spp., Porphyromonas gingivalis, Pseudomonas aeruginosa, and Tanerella forsythia, were found. Chemical spectroscopy revealed, despite the normal signals from Ti, O, and C, also peaks of P, F, S, N, and Ca. A normal histologic image of osseointegration was observed in the apical part of the retrieved implant. Conclusion: Radiographic evidence and 25% implant failures are indications of a low success rate. High counts and prevalence of significant pathogens were found at surviving implants. Although extensive bone loss had occurred in the coronal part, the apical portion of the implant showed some bone to implant integration. [source]

Clinical Outcome of Overdenture Treatment on Two Nonsubmerged and Nonsplinted Astra Tech MicrothreadÔ Implants

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2009
Hugo De Bruyn DDS
ABSTRACT Background: The use of two implants for mandibular overdenture stabilization improves the patients' comfort and well-being. This treatment could be more cost-effective if surgery and prosthetic treatment could be performed by one clinician in the normal setting of a dental clinic. Purpose: The aim of this retrospective clinical study was to describe implant success, restorative outcome, and the patients' opinion of mandibular overdenture treatment on two early-loaded, nonsplinted Astra Tech TiOblast MicrothreadÔ (Astra Tech Dental, Mölndal, Sweden) implants. Materials and Methods: Thirty-seven consecutive patients treated with implant-supported mandibular overdentures were invited for a clinical examination. Implant survival, marginal bone level, quality of implant and prosthetic treatment, and the patients' opinion by means of questionnaires were scored. Results: Thirty-four patients attended the examination. Two implants were lost in one patient and the failure rate for the total group of patients was 3%. As 8 of the 33 remaining patients were still in the provisional loading stage, they were not included in the final clinical and radiographic examination. Based on 25 patients and 50 implants with a mean follow-up of 18.8 months (range 4,33), implant positioning and occlusion/articulation scored perfect in 74 to 80% of the cases. Retention of the dentures was rated perfect in 80%, but 20% needed minor activation of the attachments, 20% showed signs of abrasion, and 20% had already been repaired. The average marginal bone level was 0.8 mm below the reference point. The mean pocket depth was 2.1 mm, and 54% of the peri-implant tissues were free of bleeding. The patients were appreciative of the work carried out by their dentist and they indicated a significant improvement in their well-being and quality of life. Conclusions: It can be concluded that the Astra Tech implant system was successfully used by the general dentist both surgically and prosthetically with minimal implant failures and prosthetic complications and that this led to high levels of patient appreciation and overall satisfaction. [source]

Clinical and Microbiological Determinants of Ailing Dental Implants

Early Complete Failures of Fixed Implant-Supported Prostheses in the Edentulous Maxilla: A 3-Year Analysis of 17 Consecutive Cluster Failure Patients

Vertical ridge augmentation of the atrophic posterior mandible with interpositional bloc grafts: bone from the iliac crest vs. bovine anorganic bone.

CLINICAL ORAL IMPLANTS RESEARCH, Issue 12 2009
Clinical, histological results up to one year after loading from a randomized-controlled clinical trial
Abstract Objectives: To compare two different techniques for vertical bone augmentation of the posterior mandible: bone blocs from the iliac crest vs. anorganic bovine bone blocs used as inlays. Materials and methods: Ten partially edentulous patients having 5,7 mm of residual crestal height above the mandibular canal had their posterior mandibles randomly allocated to both interventions. After 4 months implants were inserted, and after 4 months, provisional prostheses were placed. Definitive prostheses were delivered after 4 months. Histomorphometry of samples trephined at implant placement, prosthesis and implant failures, any complication after loading and peri-implant marginal bone-level changes were assessed by masked assessors. All patients were followed up to 1 year after loading. Results: Four months after bone augmentation, there was statistically significant more residual graft (between 10% and 13%) in the Bio-Oss group. There were no statistically significant differences in failures and complications. Two implants could not be placed in one patient augmented with autogenous bone because the graft failed whereas one implant and its prosthesis of the Bio-Oss group failed after loading. After implant loading only one complication (peri-implantitis) occurred at one implant of the autogenous bone group. In 16 months (from implant placement to 1 year after loading), both groups lost statistically significant amounts of peri-implant marginal bone: 0.82 mm in the autogenous bone group and 0.59 mm in the Bio-Oss group; however, there were no statistically significant differences between the groups. Conclusions: Both procedures achieved good results, but the use of bovine blocs was less invasive and may be preferable than harvesting bone from the iliac crest. [source]

Titanium allergy in dental implant patients: a clinical study on 1500 consecutive patients

Fate of monocortical bone blocks grafted in the human maxilla: a histological and histomorphometric study

CLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2003
Ilara R. Zerbo
Abstract: Local bone defects in the anterior maxilla are commonly grafted with monocortical blocks of autologous bone in order to restore the defect site prior to the placement of dental implants. Increasing evidence suggests that osteocytes are involved in the control of bone remodelling and thus may be important for optimalisation of bone structure around implants, and thus for implant osseointegration. However, it is not well known whether osteocytes will survive when bone blocks are grafted into defects. We grafted 19 patients with monocortical bone blocks derived from the symphysis, to the defect site in the maxillary alveolar process. The bone grafts were left to heal for times varying from 2.5 to 7 months. During implant installation, bone biopsies were removed using a trephine burr, and processed for hard tissue histology. Bone histology and histomorphometry were then carried out in order to gain insight into the density, viability and remodelling of the graft. Clinically, all the bone grafts were successful, with no implant failures, and little resorption was seen. Histologically, bone volume expressed as percentage of tissue volume at the implant site varied from 27% to 57% with an overall average of 41%. Bone fields with empty osteocyte lacunae were observed and measured. The amount of this so-called nonvital bone (NVB) varied between 1% and 34% of the total tissue volume. The amount of NVB decreased significantly with the time of healing. The data suggest that the majority of the osteocytes of the monocortical bone do not survive grafting. The results indicate that the NVB is progressively remodelled into new vital bone 7 months after grafting. Résumé Les lésions osseuses locales dans le maxillaire antérieur sont souvent greffées avec des blocs monocorticaux d'os autogène afin de restaurer le site avant le placement d'implants. Il semble de plus en plus évident que les ostéocytes sont induits dans le contrôle du remodelage osseux et pourraient donc être importants pour optimiser la structure osseuse autour des implants et donc l'ostéoïntégration implantaire. Cependant le taux de survie des ostéocytes lorsque les blocs osseux sont greffés dans les lésions n'est pas suffisament connu. Dix-neuf patients ont été greffés avec des blocs osseux monocorticaux provenant de la symphyse dans le site de la lésion au niveau des alvéoles maxillaires. Les greffons osseux sont restés in situ durant des périodes de 2,5 à 7 mois. Pendant l'insertion des implants des biopsies osseuses ont été prélevées avec un trépan et analysées par histologie. L'histologie osseuse et l'histomorphométrie ont été effectuées afin d'analyser la densité, la viabilité et le remodelage osseux. Cliniquement tous les greffons osseux ont été effectués avec succès sans aucun échec implantaire et peu de résorption. Histologiquement, le volume osseux exprimé en tant que pourcentage du volume tissulaire au site implantaire variait de 27 à 57 % avec une moyenne totale de 41 %. Les champs osseux avec une lacune d'ostéocytes vides ont été observés et mesurés. La quantité d'os non-vivant variait de 1 à 34 % du volume tissulaire total. La quantité d'os non-vivant diminuait significativement avec le temps de guérison. Ces données suggèrent que la majorité des ostéocytes de l'os monocortical ne survivent pas au greffage. Les résultats indiquent que l'os non-vivant est progressivement remodelé en nouvel os vivant en sept mois après le greffage. Zusammenfassung Das Schicksal von monokortikalen Knochenblöcken, welche in die menschliche Maxilla transplantiert werden: eine histologische und histomorphometrische Studie Lokale Knochendefekte in der anterioren Maxilla werden normalerweise mit monokortikalen Blöcken aus autologem Knochen aufgebaut, um den Defekt vor der Eingliederung von dentalen Implantaten aufzufüllen. Aufgrund zunehmender Evidenz wird vermutet, dass Osteozyten an der Kontrolle der Knochenremodellierung beteiligt und daher wichtig für die Optimierung der Knochenstrukturen um Implantate und für die Osseointegration der Implantate sind. Es ist jedoch nicht ausreichend bekannt, ob Osteozyten überleben, wenn Knochenblöcke in Defekte transplantiert werden. Bei 19 Patienten wurden monokortikale Knochenblöcke von der Symphyse in den Defektbereich des Alveolarfortsatzes im Oberkiefer transplantiert. Die Knochentransplantate heilten in einer Zeit zwischen 2.5 und 7 Monaten ein. Während der Implantation wurden mit einer Hohlfräse Knochenbiopsien entnommen und für die Hartgewebshistologie aufgearbeitet. Der Knochen wurde histologisch und histomorphometrisch untersucht, um Einsicht in die Dichte, Vitalität und Remodellierung des Transplantats zu erlangen. Klinisch waren alle Knochentransplantate erfolgreich eingeheilt. Es konnten keine Implantatmisserfolge gesehen werden und es traten nur geringe Resorptionen auf. Histologisch variierte das Knochenvolumen, ausgedrückt als Prozentsatz Gewebevolumen an der Implantatstelle, von 27% bis 57% mit einem Durchschnitt von 41%. Knochenfelder mit leeren Osteozytenlakunen konnten beobachtet und ausgemessen werden. Die Menge dieses sogenannten nicht-vitalen Knochens variierte zwischen 1% und 34% des totalen Gewebevolumens. Die Menge des nicht-vitalen Knochens nahm signifikant mit der Länge der Einheilzeit ab. Die Daten lassen vermuten, dass die Mehrzahl der Osteozyten des monokortikalen Knochens die Transplantation nicht überleben. Die Resultate zeigen, dass der nicht-vitale Knochen innert 7 Monaten nach der Transplantation progressiv in neuen vitalen Knochen umgebaut wird. Resumen Los defectos óseos locales en el maxilar anterior se injertan comúnmente con bloques monocorticales de hueso autólogo en orden a restaurar el lugar del defecto antes de la colocación de implantes dentales. Una creciente evidencia sugiere que los osteocitos están involucrados en el control del remodelado óseo y de este modo ser importantes para la optimalización de la estructura ósea alrededor de los implantes y así para la osteointegración de los implantes. Sin embargo, no se conoce bien si los osteocitos sobrevivirán cuando los bloques óseos sean injertados en los defectos. Hemos injertado a 19 pacientes con bloques de hueso monocortical derivados de la sínfisis al lugar del defecto en el proceso alveolar maxilar. Los injertos óseos se dejaron cicatrizar por un periodo de tiempo que varió entre 2.5 a 7 meses. Durante la implantación se tomaron biopsias óseas usando una fresa de trépano y se procesaron para histología de tejidos duros. Se llevaron a cabo entonces histología ósea e histomorfometría en orden a hacerse una idea acerca de la densidad, viabilidad y remodelado del injerto. Clínicamente, todos los injertos óseos tuvieron éxito sin fracasos de implantes y se observó poca reabsorción ósea. Histológicamente, el volumen óseo expresado como porcentaje de volumen tisular en el lugar del implante varió del 27% al 57% con una media general del 41%. Se observaron y midieron campos óseos con lagunas óseas vacías. La cantidad de hueso no vital disminuyó significativamente durante el tiempo de cicatrización. [source]