When can dental treatment be provided to a pregnant patient experiencing pain who needs root canal treatment (RCT)?

Correct answer: B. Whenever it is possible (whenever the patient needs it)

• A. The first trimester is the MOST CRITICAL period for organogenesis (fetal organ development). Elective treatment should be POSTPONED, but emergency/urgent treatment (like pain relief) can be provided.
• B. For a pregnant patient in PAIN who needs RCT, dental treatment should be provided WHENEVER IT IS NECESSARY, regardless of trimester. Pain and active dental infection can harm both mother and fetus (via stress, systemic infection, medications for pain). Emergency/urgent dental treatment is safe throughout pregnancy with appropriate precautions (pregnancy-safe anesthetics, avoid radiation when possible).
• C. The third trimester is acceptable for urgent treatment but patient positioning becomes challenging due to aortocaval compression risk.
• D. The second trimester is the safest for ELECTIVE dental treatment. However, the question asks about a patient in PAIN needing RCT — which is urgent, not elective.