ABSTRACT
Although the altered-cast impression technique attains stability and controlled tissue support for distal-extension removable partial dentures, the procedure is time-consuming and technique-sensitive. This study clinically compared the vertical displacement of distal-extension removable partial dentures made from different impression techniques. The impressions studied were the altered-cast impression, an impression made from a border-molded custom tray, and a stock tray irreversible hydrocolloid impression that served as a control. A post hoc analysis, using a Tukey Q-test, exhibited significance (p less than 0.01) between the two impression techniques after intraoral loading was performed. Although statistically significant, the 0.19 mm difference between the impression techniques may or may not be clinically relevant. Additional research is required in this area.
Subject(s)
Dental Impression Technique , Denture Bases , Denture Design , Denture Retention , Denture, Partial, Removable , Alginates , Dental Abutments , Dental Clasps , Dental Impression Materials , Dental Impression Technique/instrumentation , Double-Blind Method , Humans , Movement , Rotation , Stress, Mechanical , Sulfides , Surface PropertiesABSTRACT
With a distal-extension removable partial denture, maximum use of existing oral structures can aid in the total support of the prosthesis and reduce the force on the solitary abutment. Four rests with relieved and unrelieved guide plates were evaluated for optimum stress distribution around the root of a solitary premolar abutment. These rests were the mesial, the distal, the mesial and distal, and the continuous rest. The findings demonstrated that The continuous rest had the most favorable stress concentration. All other rest designs demonstrated more lateral stress than the continuous rest. Relieved guide plates demonstrated 58% less maximum shear stress in the apical portion than unrelieved guide plates.
Subject(s)
Dental Abutments , Denture, Partial, Removable , Dental Stress Analysis , Denture Design , Elasticity , Humans , Models, Biological , Stress, MechanicalSubject(s)
Bone Plates , Dental Implantation, Endosseous , Dentures , Jaw, Edentulous/surgery , Adult , Aged , Humans , Mandible/surgery , Middle Aged , Postoperative Complications , Surgical StaplersABSTRACT
This study compared selected arbitrary hinge axis locations with the kinematic axis location. Fifty subjects were studied, and the data were statistically analyzed. Results showed significant differences between the location of experimental arbitrary axis point and those of Beyron, Gysi, and Bergstrom in relation to the kinematic axis. The arbitrary points of Beyron, Gysi, and Bergstrom showed directional tendencies, whereas the experimental arbitrary points were evenly distributed around the kinematic axis. This study indicates that the experimental arbitrary axis point more closely and consistently approximated the kinematic axis than the arbitrary points of Beyron, Gysi, and Bergstrom. The finding suggests that the clinical use of a point on Camper's line, 10 mm from the superior border of the tragus, results in a more accurate transfer of the maxillary cast to the articulator.
