Rajat Sachdeva on Instagram: "🦷 What Is a Crown with Onlay Preparation? A crown with onlay preparation (also called partial crown or conservative crown) refers to a full-coverage restoration where more natural tooth structure is preserved—especially in areas like cusp tips or marginal ridges—unlike traditional crown preparations that require aggressive reduction of all surfaces. This technique is commonly used when: The damage or decay doesn't necessitate full circumferential reduction.