When using floss as a guide for the rubber dam, where is it applied?

When using floss as a guide for the rubber dam, it is applied through the contacts. This technique is important because it allows the dental professional to navigate between the teeth without causing damage to the dental tissue or the rubber dam itself. By threading the floss through the interproximal spaces, it provides a clear pathway for the rubber dam clamp to be placed correctly, ensuring that the rubber dam imparts a tight seal around the tooth. This seal is crucial for maintaining a dry and isolated working area during dental procedures, facilitating optimal conditions for treatment.

Other methods, such as placing floss along the margins or over the surfaces, do not effectively serve the purpose of guiding the rubber dam. Additionally, positioning floss under the gingiva is not appropriate as it can cause irritation or discomfort to the periodontal tissues and may not allow for the proper placement of the rubber dam. Hence, applying floss through the contacts is the most effective and appropriate method.