A comparison of stress distribution and flexion among various designs of bar attachments for implant overdentures: a three dimensional finite element analysis.
(26/69)
CONTEXT: Bar overdentures are popular choices among clinicians worldwide but configurations that provide an optimal biomechanical distribution of stress are still debatable. AIMS: To compare the stresses and elastic flexion between implant supported bar overdentures in various configurations using finite element analysis. SETTINGS AND DESIGN: A CAT scan of a human mandible was used to generate an anatomically accurate mechanical model. MATERIALS AND METHODS: Three models with bars and clips in three different configurations were constructed. Model 1 had a single bar connecting two implants, Model 2 had three bars connecting all the four implants, and Model 3 had two bars connecting the medial and distal implants on the sides only. The models were loaded under static conditions with 100N load distributed at the approximate position of the clip. The mandibular boundary conditions were modeled considering the real geometry of its muscle supporting system. Maximum von Mises stress at the level of the bar and at the bone implant interface were compared in all three models. The flexion of mandible and the bar was also compared qualitatively. STATISTICAL ANALYSIS USED: The analyses were accomplished using the ANSYS software program and were processed by a personal computer. Stress on these models was analyzed after loading conditions. RESULTS: Qualitative comparisons showed that stress at the level of the bar and at the bone implant interface were in the following order: Model 1> Model 3> Model 2. The flexion of the mandible and the bar were in the following order: Model 2 > Model 1 > Model 3. CONCLUSIONS: Four implant bar systems connected by bars on the sides only is a better choice than two implant bar systems and four implant bar systems with bars connecting all four implants. (+info)
The knowledge and attitude of general dentists toward denture adhesives in Tehran.
(27/69)
Use of distal implants to support and increase retention of a removable partial denture: a case report.
(29/69)
Lack of adequate support (tooth/soft tissue) results in displacement of bilateral and unilateral distal extension removable partial dentures. Placement of implants is one option for managing this problem. The aim of this report is to describe fabrication of a mandibular removable partial denture supported by 2 unilateral distal implants with locater attachments. The patient was a 70-year-old man who was missing the right mandibular premolars and molars. After an uneventful 3-month healing period, the locater abutments were tightened on the implants. At a recall appointment 18 months later, neither of the implants had been lost, but some marginal bone loss (mean 0.3 mm, standard deviation 0.1 mm) was noted. The patient reported no displacement of the distal extension removable partial denture. This case report suggests that distal implants may help to prevent displacement of distal extension removable partial dentures, and may be especially suitable for patients who cannot afford implant-supported fixed dental prostheses. (+info)
Correct complete denture rehabilitation, a chance for recovering abused tissues.
(30/69)
The prosthodontic treatment must provide for the edentulous patients bio-functional prosthetic restorations, bio-prophylactic for the surrounding tissues. In this aim, an edentulous patient must be submitted to a methodical clinical examination in order to establish the quality of hard and soft tissues, which will indicate the degree of difficulty of the prosthetic treatment. Additional investigation as a microbiologic examination and cephalometric radiographs can be useful in a modern investigation. In our daily practice, we are rarely confronted with a normal morphology of the denture bearing oral structures. The problem of managing abused tissues in a patient with morphologic abnormalities due to faulty prostheses is sometimes difficult to solve. Preventing the deterioration of oral status must be a condition in providing a chance for the success of the following rehabilitations, mainly in the situation when the complete edentulousness succeeds in a young or middle age patient. (+info)
Overdenture - implants versus teeth - quality of life and objective therapy evaluation.
(31/69)
An overdenture is a complete or removable partial denture that has one or more tooth roots or implants to provide a support. The study compares two types of prosthodontic treatment - overdenture supported by remained own teeth with ball attachments and that held by implants. The cohort of 35 patients (recall from 1 to 5 years) was evaluated. When subjectively and objectively assessed no significant difference between both groups was observed. (+info)
Effect of retorque on loosening torque of prosthetic screws under two levels of fit of implant-supported dentures.
(32/69)