“Sedation dentistry” refers to the use of pharmacological agents to calm and relax a patient prior to and during a dental appointment. The pharmacological agents usually belong to a class of drugs called sedatives, which exert their action by depressing the central nervous system, specifically those areas concerned with conscious awareness. Therefore, sedation dentistry is useful for any dental procedure (like dental cleaning, dental fillings, root canals, crowns and bridges, implants and bone grafts, etc.) that might be uncomfortable for some patients.

Source: Wikipedia