Cavity preparation when using Cention N without an adhesive
When using Cention N without an adhesive, the preparation guidelines for the placement of amalgam fillings apply (retentive preparation design, resistance form).
Retentive undercuts need to be prepared in all areas of the cavity. Enamel portions not supported by dentin must be avoided.
In order to prevent fractures of Class II fillings, the area of the isthmus should be sufficiently deep and wide: on the occlusal/proximal aspect it should be at least 1.5 mm in depth, and on the buccal/oral aspect