How should the instrument tip be oriented when removing cement from facial and lingual embrasures?

When removing cement from facial and lingual embrasures, orienting the instrument tip occlusally and placing it under the edge of the cement is the most effective technique. This approach allows the dental assistant to access the cement more easily and helps ensure that the instrument can lift the cement away from the tooth surface without causing harm to the adjacent structures.

By tipping the instrument occlusally and positioning it under the edge of the cement, the operator can create a leverage point that helps to dislodge and remove the cement efficiently. This method minimizes the risk of damaging the surrounding enamel or gingiva, which can occur if the instrument is improperly directed or angled.

The other options do not facilitate effective cement removal. For instance, pointing the instrument towards the floor or tipping it apically could compromise access and control, making it challenging to remove the cement effectively. Similarly, placing the instrument perpendicular to the tooth surface might not provide the necessary angle to lift the cement away, potentially leaving residue and increasing the likelihood of complications.