ABSTRACT
An indirect post and core technique in which the core is waxed and invested with the die has been described. The post and core are cast directly into the invested die, which has the advantage of an accurate casting of the post preparation obtained with less laboratory time and without the disadvantages of retrieving an intact wax pattern. This technique is particularly suited for long, narrow post preparations; short preparations where precise fit is necessary for retention; and multiple adjacent post preparations.
Subject(s)
Crowns , Dental Casting Technique , Post and Core Technique , Calcium Sulfate , Humans , Models, DentalSubject(s)
Dental Alloys , Dental Bonding , Dental Porcelain , Dental Stress Analysis , Gold Alloys , Palladium , Platinum , Stress, MechanicalABSTRACT
As with other direct-indirect methods, the Duralay index method has the advantage of not depriving patients of their dentures. The index takes very little time to fabricate since it is only necessary to obtain a Duralay mold of the internal surface of the clasp assembly and the external surface of the prepared tooth. In addition, the index will serve as a guide for the final waxup. In waxing, it will only be necessary to fill in the contours and margins without touching the index surfaces which contact the clasp assembly and occlusal stops. If occlusal stops were incorporated in the index, no opposing cast is necessary. This method may be used with full veneer and veneered crowns and any impression technique and die material providing that the expansion during investing and casting results in a passive fit of the crown.
Subject(s)
Crowns , Dental Abutments , Denture Design , Acrylic Resins , Denture, Partial, Removable , HumansABSTRACT
The influences of the marginal design of a full crown on the occlusal seat and marginal seal of a cemented full crown restoration was examined. Under the conditions of the study, the featheredge and parallel bevel preparations demonstrated the best marginal seal, followed in order by the full shoulder, 45-degree shoulder, and finally the 90-degree shoulders with 30-degree and 45-degree bevels. With regard to seating of the restoration, the 90-degree full shoulder demonstrated the best seat, followed in order by the 45-degree shoulder, 90-degree shoulder with 45-degree bevel, featheredge, 90-degree shoulder with 30-degree bevel, chamfer with parallel bevel, and finally 90-degree shoulder with parallel bevel.
