American Board of Orthodontics (ABO) Practice Exam 2025 - Free Orthodontics Practice Questions and Study Guide

The correct choice is silver (Ag) because it possesses intrinsic antibacterial properties that effectively reduce biofilm formation. This characteristic is particularly useful in orthodontic applications, as biofilms can harbor bacteria that contribute to dental caries and periodontal disease. By incorporating silver into resin-modified glass ionomer cement (RMGIC), the material not only adheres to the brackets and promotes a strong bond but also inhibits the growth of bacteria around the brackets. This leads to a healthier oral environment for patients undergoing orthodontic treatment.

Other materials mentioned, such as calcium, fluoride, and zinc, also have beneficial properties in dentistry, but they do not exhibit the same level of biofilm activity reduction as silver does. For instance, fluoride plays a crucial role in remineralization and strengthening tooth enamel, thereby reducing the risk of caries, but it does not demonstrate the direct antibacterial effects that silver does. Consequently, while these materials have their own benefits in the context of orthodontics and oral health, silver is specifically recognized for its ability to combat biofilm activity effectively.