Also the long-term function of a dental implant system will depend on the biomechanical interaction between bone and implant. If these stresses exceed the physiological limit they may lead to several undesirable results. These retentive attachments generate forces and stresses that differ from those seen with natural teeth supported by periodontal ligament. Retention for the mandibular implant-supported overdentures is commonly achieved by ball attachments, clip on bar connecting the implants, or magnetic attachments. Implant-supported overdentures have gained acceptance over the complete denture because of its relative simplicity, increased comfort and chewing efficiency, greater satisfaction, preservation of residual ridge, retention, stability, and improved patient quality of life.

Mandibular implant retained overdentures can provide an effective treatment modality for these patients and, in particular, those who have persistent problems with a conventional mandibular prosthesis. The introduction of osseointegrated implants into dentistry has provided new alternatives for the rehabilitation of edentulous patients. Lack of retention and stability is one of the major complaints of edentulous patients. Treating older patients, especially those with disabilities, may be a demanding challenge. The implant with Hader bar attachment with a 3 mm stiffener is the best in terms of stress distribution, where the stress is concentrated at the bar and stiffener regions.Īs life spans lengthen, a significant number of people outlive their teeth. In model C the maximum stress concentration was in the bar attachment making it the model with the best stress distribution, as far as implant failures are concerned. The results showed that the maximum stress concentration was seen in the neck of the implant for models A and B. These different models were analyzed by the Finite Element Software (Ansys, Version 8.0) using von Mises stress analysis. A CT scan of edentulous mandible was used and three models with 1, 2, and 3 mm thick stiffeners were created and subjected to loads of emulating the masticatory forces. The stiffener of the bar attachments was varied and the stress distribution to the bone around the implant was studied. This study aims to analyze the force transfer and stress distribution of an implant-supported overdenture with a Hader bar attachment. But the ideal thickness of the stiffener to be attached to the bar is a subject of much debate. The effect of adding a stiffener to the tissue side of the Hader bar helps to reduce the transmission of the stresses to the alveolar bone. A key factor for the long-term function of a dental implant is the manner in which stresses are transferred to the surrounding bone.

Finite element analysis