What type of bur is typically used to create adjustments in crown preparations?

The flame-shaped bur is typically used to create adjustments in crown preparations because its unique design allows for precise contouring and shaping of dental materials. The tapered and elongated shape of the flame bur facilitates access to various angles and contours of the tooth preparation, which is especially important in achieving a proper fit for crowns. This shape helps in refining margins and enhancing the aesthetics of the restoration.

While other burs have their specific uses in dental procedures, the flame-shaped bur is distinctively suited for making these fine adjustments during crown preparation. The round bur, for example, is more commonly used for cavity preparations or to remove carious dentin, while the diamond bur is often utilized for cutting and shaping harder materials due to its diamond coating. High-speed burs can be used for rapid reduction of tooth structure but are not specifically designed for the finesse required in adjustments of crown preparations.