A DENTIST who reconstructed a patient's mouth when the man required work to only three teeth has been ordered to pay more than $345,000 in compensation and interest.

Todd Dean had been working as an apprentice tree lopper when a small log struck him on the chin at a job in Bexley in December 2001.

He rinsed his bleeding mouth with salty water, ''spat out a few chips of teeth'' and returned to work for the rest of the day, only later complaining to his boss about the continuing pain to his mouth and teeth.

Dr Mark Phung, who treated Mr Dean on numerous occasions in 2002 and 2003, charged his employer's insurance company $73,645 to perform root canals on each of his 28 teeth. In one bill, Dr Phung charged the insurer $28,740 for work performed on two occasions. In another, he charged $10,000 for one session.

One dental expert who reviewed Mr Dean's mouth said the work was ''a complete case of fraud … by the dentist'' and an ''extremely poor dentistry job''.