Which type of bur is preferred for finishing composite restorations due to its smooth cutting action?

The preference for a diamond bur when finishing composite restorations is largely due to its smooth cutting action, which allows for precise and refined adjustments to the restoration surface. Diamond burs are made with diamond particles that create a very fine cutting action, ideal for achieving the desired smoothness on the surface of composite materials. This reduces the risk of scratching or roughening the restoration, leading to an aesthetically pleasing finish that integrates well with the natural tooth surface.

In contrast, carbide burs, while effective for cutting and shaping, tend to produce a rougher finish due to their more aggressive cutting capability. They are suitable for bulk removal of material but may not provide the level of smoothness required after finishing a composite restoration. Round burs are typically used for initial cavity preparation and removal of decay rather than for finishing. Flame burs can be useful for contouring but do not provide the same fine finishing qualities as diamond burs. Therefore, for the task of finishing composite restorations, a diamond bur is the optimal choice due to its ability to create a smooth, polished surface with high precision.