A 38-year-old man attends at night with pain from his lower left first molar that woke him from sleep. The tooth has a deep MOD amalgam; cold produces severe pain lingering about 40 seconds, the tooth is tender to percussion, and the periapical radiograph shows only a widened PDL space. He has no swelling, no fever, and he insists on 'strong antibiotics'. What is the most appropriate emergency management?