A dentist accused of sexually assaulting three patients allegedly mouthed "I love you" to one woman after touching her body with his hand.

Nasheet Michael, 58, faces 15 charges, including indecent assault and unlawful assault, over his alleged conduct in 1996, 2013 and 2014 with women patients who were in the dentist's chair and undergoing work on their teeth.

Prosecutors allege he put his hand down one woman's jeans at his Dandenong clinic in 2014 while a dental nurse was performing treatment, and afterwards said "Smile" and told the woman she needed another appointment.

In 1996 at a clinic in Cheltenham, Dr Michael is alleged to have touched his patient's breast – over her clothing – with the back of his hand and mouthed the word "Sorry". But during the treatment, prosecutors allege, he also mouthed "I love you" to the shocked patient.

Dr Michael was in Melbourne Magistrates Court on Monday for the first day of a hearing that will determine whether he stands trial.

The court was closed while the women gave evidence. The women are aged in their 40s.

According to a prosecution summary released by the court, police say the woman in 2014 closed her eyes to block out Dr Michael's actions, and thought she heard him say "Shhh" while the nurse was using a dental tool.

There is no suggestion in the summary that dental nurses knew of the alleged offending.

In 2013, police allege the dentist moved his fingers in and out of the patient's hand, pressed himself against her and touched her breast.

Dr Michael denied the offending to police and told them he was a caring dentist who touched a patient's shoulder or held their hand if they appeared apprehensive.

He told police his wife had advised him not to be that way because people might misinterpret his actions.

The hearing continues.