Final answer:
The dental procedures involving dental prophylaxis, treatment follow-up, and periodontal treatment are classified as preventive dental care.
Step-by-step explanation:
The dental procedures involving dental prophylaxis, treatment follow-up, and periodontal treatment are classified as preventive dental care (a). Preventive dental care aims to prevent dental diseases and maintain oral health. Dental prophylaxis involves professional teeth cleaning to remove tartar and plaque, while treatment follow-up refers to the monitoring and management of ongoing dental issues. Periodontal treatment focuses on treating gum disease and maintaining the health of the supporting structures around the teeth.