The flight instructor reported that, during a night landing, the student pilot relaxed back pressure and the nose landing gear struck the runway. The airplane bounced, the instructor took the flight controls, and he settled the airplane back onto the runway. They taxied off the runway, did not observe anything wrong with the airplane, and continued two more take offs and landings without further incident.
During the 100-hour inspection the next day, it was observed that the airplane sustained substantial damage to the fuselage.
The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation.