Which of the following describes the function of prophylaxis in dental care?

Prophylaxis in dental care is primarily focused on preventing new decay and maintaining oral health. This preventive measure involves procedures such as professional cleanings to remove plaque and tartar buildup, which can lead to cavities and gum disease if not addressed. By keeping the teeth and gums clean and healthy, prophylaxis plays a vital role in reducing the risk of dental problems before they develop, making it essential for long-term oral health.

In contrast, addressing existing decay pertains to restorative procedures, which is unrelated to prophylaxis. Removing residual cement after crown placement and focusing on cosmetic improvements are also not aligned with the primary purpose of prophylaxis, as they deal with specific restorative or aesthetic aspects of dental care rather than prevention.