Which dental instrument is known for its use in laboratory settings to adjust outside appliances?

The laboratory bur is specifically designed for use in dental laboratories and is utilized to modify or adjust dental appliances such as crowns, bridges, and dentures. Its construction is suitable for cutting and shaping materials used in these appliances, including metal and acrylic, which is crucial for achieving the desired fit and function.

The surgical bur, on the other hand, is intended for procedures in a clinical setting, typically for cutting tooth structure or bone in surgical procedures. Round burs are versatile instruments used primarily for cavity preparation and shaping tooth structure during restorative work. An amalgam carrier is used for the dispensing and placement of dental amalgam material rather than for adjusting appliances. Thus, the laboratory bur stands out as the correct choice for specifically addressing modifications in a laboratory context.