When the biting surface of a back tooth needs a restoration, an excellent choice is often a porcelain inlay or onlay. Porcelain restorations have many benefits. Like all restorations, porcelain protects your tooth and is a very strong and durable material.rnrnAll Porcelain onlays, and inlays can be constructed to replace both mercury and semi permanent white fillings. They can also restore teeth to their natural form and anatomy so you can chew and crush foods properly. Porcelain onlays can create a beautiful, clean, natural mouth with strengthened teeth for health and longevity.rn Less