ATHENS, Greece (AP) _ A dentist whose patients accused him of leaving them in agony by using various contraptions, including oversized screws for dental implants, was sentenced to four years in prison, local media reported Wednesday.

Theodoros Vassiliadis was convicted of causing bodily harm to seven patients. According to one television station, he used screws taken from television sets to fix implants in patients' mouths.

``He destroyed the whole upper part of my mouth,'' local media quoted one of his patients, Nikos Mastrokalos, as testifying. ``The screws he put in were 30 millimeters (1.2 inches) long.''

Another former patient, Sofia Grigoriadis, said the implants placed in her mouth ``pierced my sinuses,'' media said.

Most of the patients said they had found Vassiliadis through an advertisement in a magazine, and had given him down payments before he began working on their teeth.

Vassiliadis insisted his methods were pioneering, and arrived in court armed with two bags full of documents he claimed proved his qualifications and methods.

He said the charges brought against him were the result of professional rivalry from other dentists who wanted to defame him, media reported.

The dentist left the courtroom before the end of the trial, and was informed of the verdict by telephone at his office. He remained free while his lawyer appealed the conviction.