Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “DENTAL IMPLANTATION”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 955 records · Page 53Linked to original sources

[A biomechanical study of the mechanical stress transmission of dental implants using finite element analysis. Part II. Experiments].

In the first part of this two-part study the possible uses of finite element analysis in studying the stress transmission of dental implants were reviewed. In the present second part our own experiments are presented. In the first series the effect of the geometric parameters and load types on mechanical stresses arising around cylindrical implants in bone were studied with 2D and 3D finite element analysis. In the second series the stress transmissions of various implant geometries were compared and an attempt was made to determine the optimal implant shape from the point of view of stress transmission.

Dental Implants↗

Oxide thickness and surface contamination of six endosseous dental implants determined by electron spectroscopy for chemical analysis: a preliminary report.

Electron spectroscopy and argon ion etching were used to determine the depth and composition of the oxide layers of six competitive dental implant systems. To minimize problems associated with analyzing the active oxide layers, the implants were removed from their original packaging in an oxygen-free environment. The majority of the six implant systems were found to have similar oxide thickness in the range of 20 to 34 A. Some variation was found in the extent of non-oxide surface contamination.

Corrosion↗

Predictable crestal bone remodelling around two porous-coated titanium alloy dental implant designs. A radiographic study in dogs.

We have previously suggested that altering the height of the porous-coat segment of a partially porous-coated TiAl6V4 endosseous dental implant would affect the degree of crestal bone loss occurring during implant function by changing the patterns of stress transfer. This conclusion arose from the analysis of data from several different experiments and lacked a direct intra-animal comparison. In the present study we have compared two implant designs varying only in the extent to which they were porous-coated. With one design (type A) the coronal 1.8 mm of the implant root had a machined surface while the remainder of its length was porous-coated with TiAl6V4 beads. The other design (type B) had all but the coronal-most 0.75 mm porous-coated. Two implants of each type were placed in each of 4 dogs and the sites allowed to heal for 4 weeks before re-entry and prosthesis attachment. Monthly the implant-supported bridges were removed and radiographs exposed of each implant using a special film holder connected separately to each implant. These radiographs were analyzed for crestal bone loss using both direct visual and computer-assisted techniques. The results showed that bone remodelled to the machined surface-to-porous coat junction for type B implants and achieved a steady state by 12 weeks of function, whereas a longer time was required to achieve this state with type A implants. Significantly more bone loss occurred with the type A design, and this difference was detectable as early as after the first month of function.

Aluminum↗

Risk factors for dental implant failure: a strategy for the analysis of clustered failure-time observations.

This study's objective was to identify, in a statistically valid and efficient manner, the risk factors associated with dental implant failure. We hypothesize that factors exist which can be modified by clinicians to enhance outcome. A retrospective cohort study design was used. Cohort members had >or= one implant placed. Risk factors were classified as demographic, health status, implant-, anatomic-, or prosthetic-specific, and reconstructive variables. The outcome variable was implant failure. The cohort was composed of 677 patients who had 2349 implants placed. Based on the adjusted multivariate model, factors associated with implant failure were tobacco use, implant length, staging, well size, and immediate implants (p <or= 0.05). In the setting of correlated survival observations, we recommend adjusting for the correlation of the observations to provide statistically valid and efficient results. Three of the identified factors--tobacco use, immediate implants, and implant staging--potentially may be modified to enhance implant survival.

Age Factors↗

Future directions in the use of dental implants.

Future development in implant prosthodontics should be based on the fundamentals of sound research and reliable clinical implementation. The goals should be to research the safety and efficacy of implants with regard to materials, host receptor site and interfacial zone; to develop acceptable uniform standards of evaluation; and to submit findings to scientific methods of analysis in determining benefit-to-risk factors. This presentation will offer a glimpse at some current developments in basic and clinical research focusing on studies in biocompatability and host acceptance; the implant-tissue interface; processes in osteogenesis related to vascularization of host sites; and bioengineering studies related to stress analysis and dimensional accuracy of impression systems for implants. The presentation will further describe future direction in research, training and implementation of services through development of an interdisciplinary team. A center is proposed to address the need for combined efforts in clinical and basic science research, the broad scope of implant utilization, and the teaching of implant procedures within an academic setting and to our colleagues.

Dental Implantation↗

The effect of smoking on osseointegrated dental implants. Part II: Peri-implant bone loss.

PURPOSE: The detrimental effect of cigarette smoking on implant survival has been previously demonstrated. The purpose of this study was to retrospectively investigate the effect of smoking on marginal bone loss around endosseous dental implants. MATERIALS AND METHODS: The sample consisted of 767 Brånemark implants placed in 235 patients between 1979 and 1999. Bone level changes were determined using periapical radiographs taken at annual recall visits for 1 to 20 years following prosthesis insertion. Nonparametric tests and multiple linear regression were used to determine the influence of various factors on peri-implant bone loss during the first year of clinical loading and for all subsequent years. RESULTS: The mean annual bone loss was 0.178 mm +/- 0.401 during the first year of clinical loading and 0.066 mm +/- 0.227 per year thereafter. A positive smoking history was associated with a higher rate of peri-implant bone loss, and the majority of implant failures were observed in this group of patients. Smoking at the time of stage 1 surgery did not appear to predispose implants to more marginal bone loss. CONCLUSION: Cigarette smoking should not be an absolute contraindication for implant therapy; rather, long-term heavy smokers must be informed that they are at a slightly higher risk of late implant failure and are susceptible to more marginal bone loss over the long-term, irrespective of their smoking status at the time of implant placement.

Adolescent↗

Peripheral giant cell granuloma associated with dental implants.

BACKGROUND: Peripheral giant cell granuloma (PGCG) is a well-circumscribed lesion confined to the alveolar and gingival mucosa. PGCG is considered a reactive lesion caused by local irritation or trauma. The objectives of the present study were to evaluate the incidence of PGCG in peri-implant lesions submitted for histologic examination, to establish its correlation with implant failure, and to discuss its pathogenesis. METHODS: The study was conducted on 25 periimplant biopsy specimens submitted for histological examination between 1999 and 2001. Sections (5 microm) of paraffin embedded tissues were cut and stained with hematoxylin and eosin. RESULTS: From the 25 specimens, three (two males and one female, ranging in age from 31 to 69 years) were identified as peripheral giant cell granuloma. The posterior mandible was affected in two cases and the anterior maxilla in one. The clinical appearance was an exophytic mass with a bleeding surface. The time interval between implantation and lesion development was from several months to 6 years. Recurrence following curettage was found in all cases. The implants were stable; however, two were removed either because of bone loss around the implant or because of several recurrences. In all cases healing was uneventful. CONCLUSIONS: Peripheral giant cell granuloma can develop in association with dental implants. Clinically, the lesions are similar to the classical PGCG. In the present study, the precise incidence could not be concluded because of the small number of selected cases. Due to the aggressive nature of the lesion and the high recurrence rate, implants can fail unless the lesion is detected early and proper surgical removal is performed. Tissue removed from the peri-implant area should always be submitted for histologic examination for accurate diagnosis.

Adult↗

Five-year prospective follow-up report of the Astra Tech Dental Implant System in the treatment of edentulous mandibles.

This report of the 1st 2 prospective studies using the Astra Tech Implant System and fixed detachable bridges for rehabilitation of mandibular edentulism, presents clinical and radiographic data at the 5-year follow-up. The original material comprised 109 subjects, 56 of whom had been included in the original study, using the 1st generation Astra Tech Implant. Two subjects were excluded and the 3-year follow-up report was based on the remaining 54 subjects and 310 fixtures. After some minor changes to the fixture and the abutment, the 2nd generation Astra Tech Implant was used in 53 subjects and 308 fixtures. In all 16 subjects were lost to follow-up and the 5-year results are based on the remaining 91 subjects with 517 fixtures in function: 5 fixtures were lost due to mobility at abutment installation and during the 1st year, 2 fixtures were removed due to pain, and after 4 years in situ 1 fixture failed. As no clinical or radiographic differences were obvious in the annual registrations of the 2 studies the results have been combined. The fixed bridges were removed at 3 and 5 years to test each fixture and none was mobile. The cumulative fixture survival rate at 5 years was 98.7% and the bridge survival rate was 100%. Of the sites 82% were plaque free, and 96.8% showed no signs of inflammation. Over the 5-year period after bridge insertion, i.e. from baseline registration, there was only minor deterioration in marginal bone levels as measured on standardized intraoral radiographs: the mean differences in mm and standard deviations (SD) were -0.09 (0.27) in the 1st year, -0.20 (0.40) in the 3rd year, and -0.26 (0.53) in the 5th year. According to the stringent clinical and radiographic criteria by Albrektsson and co-workers, the successful treatment outcome and the survival rate in 91 subject over 5 years, indicates that the Astra Tech Dental Implant System with fixed detachable bridges is an appropriate method for rehabilitation of mandibular edentulism.

Adult↗

[Clinical and functional evaluation of the efficiency of dental implantation in patients with complete adentia].

Eleven patients with complete adentia were treated by dental implantation. Modified methods for preparing individual impression trays and differentiated functional cast models were used. Control group consisted of 30 patients with complete adentia, treated routinely. The masticatory function normalized 1 month after treatment in the main group vs. 2 months in the control group.

Dental Implantation↗

Influence of patient age on the success rate of dental implants supporting an overdenture in an edentulous mandible: a 3-year prospective study.

The aim of this study was to determine the influence of age on peri-implant tissues in patients treated with implant-supported overdentures in the mandible. A prospective study was carried out with 2 groups of healthy edentulous patients. The mean age of the younger group (n = 32) was 46 years (range 35 to 50 years); the mean age of the older group (n = 26) was 68 years (range 60 to 80 years). Two dental implants were placed in the interforaminal region of the mandible, and after a 3-month healing period, overdentures were fabricated. Clinical and radiographic parameters were evaluated immediately after completion of the prosthetic treatment, after 1 year, and after 3 years. The evaluated clinical parameters were implant loss, Plaque Index, Gingival Index, Bleeding Index, and probing depth. Radiographic evaluation was performed using a standardized long-cone technique with a direction device. Statistical analysis was carried out with SPSS software. One implant in the older group was lost during the healing period. After 3 years, the mean scores for Plaque Index, Gingival Index, and Bleeding Index were between 0 and 1 for both groups (out of possible scores of 0 to 3), and the mean probing depth was 3 mm in both groups. The mean bone loss after 3 years was 1.2 mm in the younger group and 0.8 mm in the older group, but this difference was not significant. It was concluded from this study population that the clinical performance of implant-supported overdentures in the mandible is equally successful in younger and older patients.

Adult↗

Interventions for replacing missing teeth: maintaining and re-establishing healthy tissues around dental implants.

BACKGROUND: To maintain healthy tissues around oral implants it is important to institute an effective preventive regimen (supportive therapy) and when a pathologic condition of the tissue around implants is diagnosed, an intervention should be initiated as soon as possible. Different maintenance regimens and treatment strategies for failing implants have been suggested, however it is unclear which are the most effective. OBJECTIVES: To test the null hypothesis of no difference between different interventions for maintaining or re-establishing healthy tissues around dental implants. SEARCH STRATEGY: The Cochrane Oral Health Group Specialised Register, The Cochrane Controlled Trials Register, MEDLINE and EMBASE were searched. Hand searching included several dental journals. In addition, authors of all identified trials, fifty-five oral implant manufacturers and two extensive personal libraries (ME and AJ) were consulted. SELECTION CRITERIA: All randomised controlled trials of oral implants comparing agents or interventions for maintaining or re-establishing healthy tissues around dental implants. DATA COLLECTION AND ANALYSIS: Data were independently extracted, in duplicate, by two reviewers (ME & HW). Authors were contacted for details of randomisation and withdrawals and a quality assessment was carried out. The Cochrane Oral Health Group's statistical guidelines were followed. MAIN RESULTS: Nine RCTs were identified. Five of these trials, which reported results from a total of 127 patients, were suitable for inclusion in the review. REVIEWER'S CONCLUSIONS: There is only a little reliable evidence for which are the most effective interventions for maintaining health around peri-implant tissues. There was no evidence that the use of powered or sonic toothbrushes was superior to manual toothbrushing. There is a weak evidence that Listerine mouthwash, used twice a day for 30 seconds, as adjunct to routine oral hygiene is effective in reducing plaque formation and marginal bleeding around implants. There was no evidence that phosphoric etching gel offered any clinical advantage over mechanical debridement. These findings are based on RCTs having short follow-up periods and few subjects. There is not any reliable evidence for the most effective regimens for long-term maintenance. For the treatment of failing implants (peri-implantitis) there is not any reliable evidence for preferring one therapeutic regimen over another. More RCTs should be conducted in this area. In particular, there is a definite need for trials investigating which is the most effective approach for the treatment of peri-implantitis and for trials with longer follow-up for maintenance. Such trials should be reported according the CONSORT guidelines (http://www.consort-statement.org/).

Dental Implants↗

Risk factors associated with dental implants in healthy and medically compromised patients.

A total of 104 consecutive patients treated with 313 Nobelpharma implants was studied to determine the medical risks associated with dental implants. There did not appear to be an increased implant failure rate or an increase in perioperative morbidity in patients with a compromised medical status. Age; sex; and concurrent use of hypoglycemic agents, supplemental female hormones, or steroids also did not correlate with increased implant failure or perioperative morbidity. Implant procedures using a variety of pain-/anxiety-control agents failed to reveal any increase in anesthetic-related complications. However, the number of implants placed per patient did correlate with implant failure. It appears that implant surgery and the required anesthetic appear to be safe procedures even in the medically compromised patient.

Adolescent↗

Histologic and microradiologic comparison of block and particulate cancellous bone and marrow grafts in reconstructed mandibles being considered for dental implant placement.

PURPOSE: Patterns of healing were investigated in mandibles reconstructed with three different techniques to assess their readiness for implant placement. PATIENTS AND METHODS: The subjects were 10 patients who had undergone mandibular reconstruction with either nonvascularized iliac block bone grafts (group 1; 3 patients), particulate cancellous bone and marrow (PCBM) grafts (group 2; 3 patients) for mandibular discontinuity, or PCBM grafts for mandibular marginal defects (group 3; 4 patients). Six (groups 2 and 3) or 12 months (group 1) after mandibular reconstruction, bone biopsy specimens were obtained for histologic examination with a trephine bur. As controls, bone specimens were obtained from ungrafted mandibles of patients undergoing dental implant placement. Undecalcified specimens were embedded in polyester resin and examined by routine light microscopy and microradiography. RESULTS: The morphology of the specimens from group 1 was similar to that of group 2, but not to that of the control subjects. However, the morphology of specimens from group 3 was generally similar to that of control subjects. CONCLUSION: These results suggest that mandibular reconstruction with PCBM grafts allows the placement of dental implants sooner than reconstruction with block bone grafts.

Adult↗