Chamfer

Abstract: 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.

Abstract: Apparatus for resectioning knee condyles, enabling a prosthesis to be fitted, comprising a femoral cutting device (12) comprising a support element (14), a femoral cutting blade guide (21, 24, 30) fixed and vertically adjustable in relation to the support element, a femoral intramedullary rod (28) for orienting and centering said device and feeler means (56, 57, 78) for the anterior cortical femur portion (58, 79). The cutting blade guide includes at least two blocks (21, 24, 30) movable in relation to the support element and vertically adjustable in relation to the support element and vertically adjustable in relation to one another. One of the blocks comprises means for guiding at least one anterior, posterior, anterior chamfer or posterior chamfer cut, the block also having means for guiding the remaining cutting operations.

Abstract: An improved surgical cutting surface (14) for guiding bone saws in joint surgery and similar instruments is disclosed. The cutting block (10) is provided with one or more cutting guide surfaces (14) that may be positioned on exterior faces of the block (10) or along channels (114) within the block (112). The reference cutting surface (14) of the material is composed of a material that has a Knoop hardness of 466 or greater (under a 500 gm load or greater), a chrome content of less than 10 % and a nickel content of less than 4 %. The cutting guide (12) is also variously configured with rails (18) or protuberances (22, 24) to provide a reference cutting surface having reduced frictional characteristics. Also a dual cutting block system (28, 46) for femoral resection is provided. Each of the two cutting blocks (28, 46) is configured to provide a cutting guide (42, 52) for both a standard cut and the complementary chamfer cut.