Why is it challenging to achieve accurate occlusal harmony with porcelain inlays?

Achieving accurate occlusal harmony with porcelain inlays is particularly challenging due to their fragile structure and the inherent limitations this fragility imposes on making occlusal adjustments. Porcelain inlays are designed to fit precisely within the cavity preparation of a tooth, and their material properties can restrict the extent to which they can be smoothly adjusted without risking damage to the inlay itself.

If adjustments are necessary to achieve proper occlusion, the risk of chipping or fracturing the inlay becomes significant. Unlike other restorative materials that may offer greater resilience and ease of adjustment, porcelain is more brittle, making clinicians cautious when refining occlusal contacts. Therefore, while careful planning and precise initial placement help, achieving harmony often requires very meticulous adjustments that must be approached with more care than might be required with other restorative options.

The other factors, such as the thin layer of luting agent and incomplete cusp coverage, while relevant to restoration challenges, do not directly impact the inherent difficulty with occlusal harmony as significantly as the fragility and difficulty in making adjustments does. The possibility of warping during the bonding process is also less central to the issue of achieving correct occlusal contact. Overall, the delicate nature of porcelain inlays is the primary reason