A bruxing patient has a fractured mandibular first molar with minimal remaining tooth structure and reduced interocclusal space. Which definitive crown material is most appropriate?

Correct answer: D. Monolithic (full-contour) zirconia

• A. Incorrect. PFM is strong in its metal substructure, but the VENEERING porcelain over the occlusal surface chips and delaminates readily under parafunctional load. It also demands roughly 1.5–2.0 mm of occlusal reduction, which is unavailable here. A full-metal occlusal surface would be acceptable but was not offered.
• B. Incorrect. Feldspathic porcelain has a flexural strength around 60–110 MPa and is entirely unsuitable for a posterior tooth in a bruxer; it would also require more reduction.
• C. Incorrect. A stainless steel crown is an interim or pediatric restoration, not a definitive adult crown — it cannot be accurately fitted or margined for long-term adult service.
• D. Correct. MONOLITHIC ZIRCONIA is the material of choice here. Its flexural strength (roughly 900–1200 MPa) far exceeds the alternatives, it needs only about 0.5–1.0 mm of occlusal reduction — critical when tooth structure and interocclusal space are both limited — and being full-contour it has no veneering porcelain to chip, which is the dominant failure mode in bruxers.

Note: Monolithic zirconia is measurably more abrasive to opposing enamel than glazed porcelain unless it is highly polished — polishing after any occlusal adjustment is essential, and a nightguard should still be provided for the bruxism itself.