Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Prosthesis Retention”

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 433 records · Page 24Linked to original sources
PubMedDate not supplied

Inaccurate fit of implant superstructures. Part II: Efficacy of the Preci-disc system for the correction of errors.

The Preci-disc prosthetic system for dental implants is designed to compensate for casting inaccuracies and to reduce stresses generated on the superstructure and implant components. This laboratory study compared stresses induced on the implant superstructure with various sizes of vertical discrepancy of fit, with and without the application of the Preci-disc system. A series of test casts carrying four abutment replicas were fabricated incorporating various sizes of discrepancies (10 to 100 micrometers) relative to a master superstructure. The stress generated on the superstructure was quantified using photoelastic stress analysis. It was found that the Preci-disc system was effective in reducing stresses induced on the surface of the implant superstructure particularly with greater discrepancies of fit (60 to 100 micrometers).

Composite Resins↗
PubMedDate not supplied

The effect of implant/abutment hexagonal misfit on screw joint stability.

A series of 10 incrementally larger, machined ASTM Grade 23 titanium non-segmented (UCLA type) abutments was loaded off axis with 133 N and cycled at 1150 vertical strokes per minute and 28 counterclockwise rotations per minute to determine screw joint stability. Abutment internal hexagonals ranged from 0.1065 to 0.1110 inches. External hexagonal mean flat-to-flat width was 2.684 mm. Rotational misfit between international and external hexagonals ranged from 1.94 degrees for the smallest abutment to 14.87 degrees for the largest. Screw joint failure ranged from 134,000 to 9.3 million cycles. The tightest matrix/patrix hexagonal screw joint failed at a mean of 6.7 million cycles. This study indicated that there was a direct correlation between hexagonal misfit and screw joint loosening. A rotational misfit of under 2 degrees provided the most stable and predictable screw joint.

Cluster Analysis↗
PubMed1995

Comparative stress analyses of fixed free-end osseointegrated prostheses using the finite element method.

We investigated the designs of osseointegrated prostheses in cases of free-end partial edentulism using comparative stress analyses interpreted with the two-dimensional finite element method. Seven free-end fixed osseointegrated prosthesis models with various connection designs (i.e., rigidly connected to an abutment tooth, not connected to an abutment tooth, connected to an abutment tooth with a non-rigid attachment) were studied. The stress values of the seven models loaded with vertical force were analyzed. When the prosthesis was not connected to natural abutment tooth but was supported instead by two free-standing implant abutments, lowest levels of stress in bone were noted. On the other hand, non-rigid attachments, when incorporated into a prosthesis, did not significantly reduce the level of stress in bone.

Alveolar Process↗
PubMed1995

A maxillary subperiosteal implant design that maximizes bone support and accomodates a cemented, low-profile parallel guiding planes Hader bar.

A design for the maxillary subperiosteal implant is detailed that (1) simplifies construction, (2) maximizes underlying bone support, (3) minimizes posterior forces to the "egg-shell"-thin bone under the maxillary sinuses, and 4 (accommodates the low-profile, cemented, parallel guiding planes Hader bar. This implant design maximizes bony support for the maxillary overdenture. It places the Hader bar superstructure within a precise envelope that maximizes esthetics, proper phonetics, and acrylic bulk for long-term serviceability.

Alveolar Bone Loss↗
PubMed1995

Treatment of a microvascular reconstructed mandible using an implant-supported overdenture: case report.

Oral rehabilitation of patients with mandibular discontinuity defects is a challenging problem facing both the surgeon and the dentist. Advances in microvascular surgery have provided the surgeon with methods to repair the partially resected mandible with vital bone grafts. Often, however, reconstruction of the bony defect alone does not guarantee an adequate foundation for successful conventional prosthetic rehabilitation. Osseointegrated implants placed into the microvascularized grafted bone offer an opportunity for improved function and patient satisfaction. The following case presentation reports the use of an implant-supported overdenture in a vascularized iliac bone graft to reconstruct a partially resected mandible.

Bone Transplantation↗
PubMedDate not supplied

Loaded and nonloaded titanium versus hydroxyapatite-coated threaded implants in the canine mandible.

A commercially pure titanium threaded implant was compared to a hydroxyapatite-coated threaded implant of similar geometric design and dimensions in the canine model. Bilateral posterior implants supported fixed prostheses, and some implants in the same mandibles served as unloaded control implants. Implants were evaluated clinically, radiographically, and histomorphometrically at the light microscope level to detect any differences in bone response to loaded conditions. No statistically significant differences were found between the two implant designs under loaded or nonloaded conditions with regard to mobility, probing depth, percentage of osseointegration, and crestal bone position.

Alveolar Bone Loss↗
PubMedDate not supplied

A comparative study of one implant versus two replacing a single molar.

A comparative study between one and two Brånemark implants replacing a single molar was conducted. Forty-seven individuals comprised two groups of 22 patients treated with one implant and 25 with two implants. A total of 72 implants were placed, 66 (92%) in the mandible and six (8%) in the maxilla. After the first year of function, the success rate was 99%, with only one implant lost. Between the second- and third-year follow-ups, 100% of the implants continued to function in the remaining 46 patients, giving a 3-year cumulative success rate of 99%. The marginal bone loss between 1 and 3 years of function was 0.10 mm (SD 0.20) for the group with one implant and 0.24 mm (SD 0.20) for the group with two implants. No changes were observed in the Sulcus Bleeding Index during the 3-year follow-up. Prosthesis mobility or screw loosening was the most frequent complication and was predominant in the group using one implant (48%), but was substantially reduced in the group using two implants (8%). These mechanical problems, using one implant only, seem to be preventable using a stronger screw joint (CeraOne abutment). Precise centric occlusal contact was established and maintained over the study period, which was thought to contribute to the very high success rate for the single-implant-supported molars, despite their high degree of mechanical problems. This study suggests that implant-supported molars can be effective therapy, and the results confirm the biomechanical analysis that two implants provide more advantageous support than does one.

Adult↗
PubMedDate not supplied

Reconstruction of the severely resorbed maxilla with dental implants in the augmented maxillary sinus: a 5-year clinical investigation.

The aim of this investigation was to determine the long-term clinical outcome and predictability of the maxillary sinus augmentation procedure utilizing a variety of bone augmentation materials. The augmentation materials evaluated were a xenograft alone (Bio-Oss), an alloplast alone (Interpore), a xenograft-alloplast combination (Bio-Oss mixed with Interpore in a 1:1 ratio), an alloplast (Interpore) mixed with autogenous bone from the iliac crest (in a 1:3 ratio), and an alloplast (Interpore) mixed with autogenous bone from the chin (in a 1:1 ratio). A total of 340 plasma-sprayed cylinder implants (IMZ) were placed, either simultaneously with the sinus augmentation procedure (235 implants), or 6 months after the procedure (105 implants) in 133 patients with insufficient bone volume in the posterior maxilla. The implants were restored with a total of 151 fixed detachable ceramometal prostheses and evaluated up to a 5-year period. Clinical evaluations included yearly assessments of peri-implant inflammation, implant mobility, and clinical attachment levels. Radiographs were also taken prior to sinus augmentation surgery, at abutment connection, at completion of the restoration, and thereafter at yearly intervals. All of the implants placed into the augmented sinuses achieved osseointegration. Only four implants (1.2%) failed to maintain osseointegration after prosthesis placement, yielding an implant survival rate of 98.8% during the entire course of the study. Of the 340 implants, 307 (90.3%) were considered successful according to the success criteria used. Gender, implant length and location, remaining bone height, and type of bone augmentation material had no effect on implant success. None of the 151 prostheses was lost during the observation period. The results of this study support the long-term clinical predictability of maxillary sinus augmentation procedures for the rehabilitation of the edentulous posterior maxilla with implant-supported prostheses.

Adult↗
PubMedDate not supplied

Cement-retained implant-supported fixed partial dentures: a 6-month to 3-year follow-up.

This study presents a follow-up of 92 implant-supported fixed partial dentures that have been cement retained for 6 months up to 3 years. Included in the study were 41 women and 29 men. A total of 225 implants were placed (86 in the maxilla and 139 in the mandible). Fixed partial dentures, including single-tooth restorations, were temporarily cemented using Temp-Bond or IRM. Complications encountered were cement washout, procelain fracture, loose central screws, and implant failure. This study suggests an alternative to screw-retained prostheses; the method presented may lower the reported complications.

Adult↗
PubMedDate not supplied

Efficacy of the intramobile connector in implant tooth-supported fixed prostheses: an experimental stress analysis.

An experimental model was designed to evaluate the effects of the intramobile connector in reducing stress concentration in an IMZ implant in fixed connection with a natural tooth abutment. The study analyzed the stresses produced at the cervical level of the implant when the superstructure arm was deflected within the limits of physiologic mobility under static axial loads. The designed experimental model was sensitive to changes in strain data with the applied loads and different internal elements. The intramobile connector resilient component reduced strain up to 60% compared to the rigid internal element.

Dental Abutments↗
PubMedDate not supplied

In vitro study of mandibular implant-retained overdentures: the influence of stud attachments on load transfer to the implant and soft tissue.

This study investigated the occlusal stress distribution to the implant and soft tissue for the implant-retained overdenture. The stress at the molar residual ridge and the strain around the implant were measured on an experimental resin cast using static and dynamic loading. The influence of connecting structures of stud attachments on stress distribution was discussed. The occlusal stress had a tendency to concentrate on the implant, especially in the areas distal to the implant. The modified magnetic attachment system, using a silicone-covered magnet, provided the optimal stress distribution.

Bite Force↗
PubMedDate not supplied

An experimental analysis of the stresses on the implant in an implant-tooth-supported prosthesis: a technical note.

When a natural tooth connected to an implant abutment by a framework is displaced within physiologic limits under functional loads, the superstructure acts as a cantilever moment arm and the implant is loaded additionally during that moment effect. The effects of a deflecting support connected to an IMZ implant, with either the IMC resilient or the titanium rigid element, were evaluated through an experimental model. The strain values measured when the moment arm was not allowed to deflect were only 30% lower than the strains measured when it was deflected within the limits of physiologic tooth mobility. The IMC was effective and achieved a reduction in the cervical strains up to 60% when compared with the rigid connector.

Bite Force↗
PubMed1995

The lingual locking screw for implant-retained restorations--aesthetics and retrievability.

The ability to retrieve a restoration is often cited as an advantage of implant-borne prostheses. Cemented prostheses, particularly in single-tooth cases, have been promoted for aesthetic reasons, and to allow increased positional flexibility in fixture placement. However, this approach may compromise restoration retrieval. This paper discusses the concept of a secondary locking screw, which allows latitude in fixture position, good aesthetics, and retrievability.

Dental Implantation, Endosseous↗
PubMed1996

Efficacy of threaded hydroxyapatite-coated implants placed in the posterior mandible in support of fixed prostheses.

A data subset from an ongoing prospective multicenter clinical study of threaded hydroxyapatite-coated implants was evaluated to assess safety and efficacy of the implants when used to support fixed prostheses in the posterior mandible. Observations were recorded before surgery, at first-stage surgery, at second-stage surgery, at loading, and at quarterly postrestoration prophylactic exams and annual comprehensive patient visits. Implant failure criteria included mobility, radiographic evidence of bone loss greater than one-third the length of the implant or peri-implant radiolucency, fracture, exfoliation, removal for any reason, and patient reported pain upon palpation. Soft tissue indices were monitored as part of the study. Postrestoration implant performance was analyzed using life-table methodology. From the 2,062 implants restored in 720 patients in the parent study, a total of 423 implants in 195 patients were included in the posterior mandibular data subset. Thirteen implants failed at or before second-stage surgery for a surgical success rate of 96.9 percent. Prosthodontics was completed, and one or more postrestoration annual follow-up visits occurred for 314 implants as of the interim analysis cutoff date. Fourteen implants failed during an observation period extending up to 62 months after completion of prosthodontic treatment. One failed implant was removed, whereas the 13 remaining implants are functional despite having been identified as failures under the protocol criteria. The Cutler-Ederer life table success rate after 5 years was 92.2 percent. Results of this investigation suggest that threaded hydroxyapatite-coated implants are effective when placed in posterior mandibular regions in support of fixed prostheses.

Adult↗