Proper Caries Removal? No You Can't without isolation.
The overwhelming majority of dentists believe that they can see caries and completely remove all caries without the benefit of a rubber dam.
No you can't.
A 25 year old male presented with fairly small amalgams with indications on radiographs that caries remained under the restorations.The amalgams were probably placed 10 or more years ago by the same dentist.
Local anesthesia was administered and a rubber dam placed. The maxillary right first and second molars were scheduled for treatment and the small amalgams removed...Signifiant amounts of retained caries were observed (no caries or leakage was noted along the walls of the restoration.) Three times the tooth structure of the original restoration was removed to eliminate all of the caries.
Few dentists can control lips, tongue, cheeks and saliva while maintaining full view of the tooth under going treatment. Even fewer dentists will be able to 100% maintain a dry field at the very posterior of the mouth.
Even if you THINK you can...No you can't.