On Tuesday, the clinic reduced services in the Walsh Building to dental emergencies, and some clinics were still closed yesterday.
The university was ''continually reassessing'' whether to reopen services, but it was uncertain whether services would be back to normal today.
University chief operating officer Stephen Willis said the decision was made after staff raised concerns about the temperature and the comfort and wellbeing of patients.
''Dental procedures can be stressful which, added to a heat stress, can impact negatively on patient safety and wellbeing.''
The city reached 29degC on Tuesday and 25degC yesterday.
Only one clinic in the building had air conditioning.
Some clinics were previously closed for a few days because of heat in January last year.
They had not been closed previously for that reason, Mr Willis said.
The building had housed more staff and services over the years in the same amount of space, he said.
''With a string of hot days, the building does not get a chance to cool down.''
Because some patients came from some distance or had to rearrange other commitments, the university was constantly reviewing the situation and would make a decision on reopening as soon as was ''reasonably feasible''.
The new dentistry building would have a heating and cooling system, and so would not have the same problems, Mr Willis said.
The new building was expected to be finished next month.
