What are hard deposits on teeth commonly referred to as?

Hard deposits on teeth are commonly referred to as dental calculus or tartar. These deposits form when plaque, which is a soft, sticky film of bacteria, mineralizes on the teeth due to the presence of calcium and phosphate from saliva. If not removed through regular brushing and professional dental cleanings, this mineralized plaque hardens and becomes calculus, which adheres strongly to the tooth surface and can only be removed by a dental professional using specialized instruments.

Understanding this terminology is important for anyone studying dental hygiene, as it helps in identifying the various forms of deposits that can affect oral health. The other choices, such as biofilm, stains, and plaque, refer to different aspects of dental health: biofilm is a collection of microorganisms on surfaces, stains refer to discolorations on teeth, and plaque is the initial soft deposit that can lead to calculus if not managed properly.