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Biomedical subjects

Y H Ismail

Publications and source records attributed to Y H Ismail.

At least 19 recordsLinked to original sources
PubMed1995

Conventional linear tomography: protocol for assessing endosseous implant sites.

Proper implant dimension and implant site selection are two major factors that affect the eventual prosthodontic rehabilitation and long-term serviceability of the implant and prosthesis. Conventional linear tomography permits accurate measurements and assessment of available bone for both factors. A protocol for the use of conventional linear tomography for diagnostic assessment, evaluation of proposed implant sites, and the selection of proper implant type and dimension is presented.

Alveolar Process↗
PubMed1993

Finite element stress analysis of tooth-to-implant fixed partial denture designs.

PURPOSE: The purpose of this study was to conduct a three-dimensional finite element stress analysis to compare models representing a natural tooth and an integrated implant connected with rigid and nonrigid prostheses. MATERIALS AND METHODS: The mathematical models described an integrated implant connected to a second premolar tooth with a three-unit metal-ceramic fixed partial denture. In one model, the tooth and implant were rigidly connected, and in the other, a nonrigid connection was assumed. From a simulated vertical load the computer generated resultant stress contours and values (compressive and tensile) in horizontal and vertical dimensions. RESULTS: A comparison of the magnitude and pattern of stresses generated in the models shows minimal differences. Although the maximum stress values were slightly higher in some areas of the rigid prosthesis model, the differences were negligible. CONCLUSIONS: Based on the similarities in both the patterns of stress contours and the stress values generated in the two models, advocating a nonrigid connection because of a biomechanical advantage may be erroneous.

Alveolar Process↗
PubMed1992

Three-dimensional finite element stress analysis of a cantilever fixed partial denture.

A three-dimensional mathematical model was generated, representing a three-unit cantilever fixed partial denture and its supporting mandibular structures. First and second premolars were used as abutments with one posterior cantilever pontic. A 5 lb vertical load was applied to the pontic. Vertical and horizontal stresses were analyzed by means of a three-dimensional finite element stress analysis technique. The results showed that a cantilever pontic creates considerable compressive stress on the abutment nearest to the pontic and produces tensile stress on the abutment farthest from the pontic.

Alveolar Process↗
PubMed1992

Reconstruction of maxillary alveolar defects with mandibular symphysis grafts for dental implants: a preliminary procedural report.

Partially edentulous patients with alveolar defects contraindicating implant placement were treated with bone grafts obtained from the mandibular symphysis. Complications encountered were minor and uneventful. Evaluation 4 months after surgery revealed minimal graft resorption, thus implant placement was possible in all potential sites. Advantages of the symphysis graft include easy access, availability of greater quantities of bone over other intraoral donor sites, low morbidity, no hospitalization, minimal discomfort, no alteration in ambulation, and no cutaneous scar. Compared with other bone regenerative methods for implant placement, a superior quality of bone was found and a shorter healing period is required. Results of this preliminary clinical investigation demonstrate that chin grafts offer a viable alternative for reconstruction of alveolar defects prior to dental implant placement.

Alveolar Bone Loss↗
PubMed1991

Post-operative maxillary cyst associated with a maxillary sinus elevation procedure: a case report.

Proper diagnosis, treatment planning, and surgical manipulation of the posterior maxilla require a thorough knowledge of the anatomy, physiology, and pathology associated with the maxillary sinus. This case report of a post-operative maxillary cyst diagnosed following routine post-operative examination of a sinus elevation procedure illustrates the need for a meticulous surgical technique, proper management of complications, and routine, long-term follow-up. With the increased utilization of sinus elevation techniques, reports of this destructive lesion may become more common.

Aged↗
PubMed1991

Three-dimensional finite element stress analysis in and around the Screw-Vent implant.

The three-dimensional finite element stress analysis method was used to determine the pattern and concentration of stresses within the Screw-Vent endosseous implant and its supporting tissues. For this commercially pure titanium implant, maximum stresses were located within the implant collar immediately below the bony crest. These stresses were at least 18 times less than the endurance limit of commercially pure titanium (259.90 MPa). Maximum stresses (19.57 MPa) in the bone were lingual to the superior portion of the collar. Previous longitudinal radiographic studies of a similar implant have revealed bone loss mesial and distal to the implant. For the Screw-Vent, mesial and distal stresses (maximum 0.38 MPa) were much lower than those buccal and lingual to the implant. The clinical significance of the stress transfer to the bone buccal and lingual to the implant has yet to be determined.

Alveolar Process↗
PubMed1985

Radiographic detection of porosities in removable partial denture castings.

The purpose of this study was to discern the existence of structural defects in removable partial denture frameworks by means of radiographs. A simple technique was described using a dental radiograph unit and routine periapical dental films. All components of removable partial denture castings were radiographed with different angulations. The visibility of defects was clear. Structural defects were located and classified in two brands of removable partial denture base metal alloys (Ticonium and Nobilium) commonly used in fabrication of removable partial denture castings. The technique described is simple, inexpensive, not time-consuming, and can be implemented with minimum instrumentation. Future studies with this radiographic method for investigation of internal defects in fixed prostheses or dental implants are recommended.

Chromium Alloys↗
PubMed1980

Radiographic study of condylar position in centric relation and centric occlusion.

The present study was conducted to compare the spatial relationship of the condyles to their fossae in the centric occlusion and centric relation positions. Right and left TMJ radiographs were obtained on 40 young adults in the two positions. Direct measurments of the anterior, posterior, and superior spaces between the condyles and their fossae were made on the radiographs. Results were statistically analyzed; the following findings and conclusions were derived: (1) In the centric relation position, both condyles were placed more posteriorly and superiorly in their fossae than in the centric occlusion position. (2) In the centric occlusion position, both condyles were symmetrically placed in their fossae with equal spatial distances anteriorly and posteriorly. (3) Greater spatial differences existed between the centric occlusion and centric relation positions on the left side, which was the orbiting (balancing)side in most subjects. (4) Further studies are needed to develop a more physiologic approach for correctly relating the mandible to the maxillae when reconstructing the occlusion in both dentulous and edentulous patients.

Adult↗
PubMed1975

Oral ulcerations associated with indomethacin therapy: report of three cases.

Oral ulcers developed in three edentulous patients who were receiving indomethacin (Indocin) therapy for rheumatoid arthritis. The lesions healed after reduction or discontinuation of the medication. These ulcers are attributed to the combined effects of the indomethacin and the dentures on the oral tissues. In older patient populations, drug-induced oral lesions must be ruled out before a dental prosthesis malfunction is implicated.

Aged↗