An electrical malfunction is suspected as the cause of a fire Wednesday night in a dental laboratory in the Pan Am building on Kapiolani Boulevard.

Four floors of the 17-story office building suffered extensive water damage from the sprinkler system as a result of the blaze, said Fire Department spokes­man Capt. Terry Seelig.

Firefighters responded to an alarm at the building at 11:27 p.m., Seelig said.

The alarm was activated on the 11th floor, although the fire actually started on the 13th floor in the offices of DenTek International Inc. dental laboratory and was put out by the building’s sprinkler system, Seelig said.

Water from the sprinkler system flooded offices in the 13th to 10th floors.

No one was injured, and there was no immediate estimate of damage.

Firefighters worked until 3 a.m. Thursday helping to clear the building of water, Seelig said.