Here are a few suggestions which might help improve the quality of dental care. Of course, more are possible.
The dentist needs to give the patient their full attention, whether during consultation or surgery etc. The patient may have to live with an error of concentration or judgement for the rest of their life.
The dentist needs to explain to the patient what he plans to do before starting. For example, if he plans to insert a self-threading screw, he needs to ask the patient's permission.
The dentist should share with the patient all information he has available regarding a decision. Technical terms should be explained to a patient in a manner that can be understood.
If the dentist proposes an action, the reasons for his conclusion should be explained to the patient. Known pros and cons should be explored.
Possible adverse reactions etc. of anaesthetics etc. should be explained.
The possibility that a woman patient may be pregnant needs to be explored. (Dental anaesthetic can lead to miscarriage.)
Patients should be discouraged from receiving general anaesthetic for dental treatment. (How many people died in Britain in 1980, while undergoing dental treatment? Answer about 40.)
Dentists should not give unnecessary x-rays (especially to children). The possibility needs to be acknowledged that x-rays may be more harmful than what is taught by dental training. (In 1988 it was discovered that x-rays were at least 4 times as harmful as originally believed. In the 1950s some children developed leukemia as a result of low level (then believed to be safe) xrays during pregnancies).
Ideally a database could contain the number of x-rays a patient has had from all sources. In Australia, it is recommended that people do not have dental xrays more than once in 2 years. Appropriate protection from scattered radiation should be available.
Dentists should make every attempt to avoid damaging healthy tissue. Micro-surgery sounds promising (as presumably less healthy tooth is destroyed, but I don't know enough to comment.
If making a composite resin filling, every effort should be made to keep the mouth dry (eg. by using a rubber dam). If replacing amalgam fillings every effort should be made to reduce exposure to mercury.
If treatment is likely to cause pain (eg. a large filling) for some time afterwards, it needs to be explained. eg. "Some people receiving a filling similar to this have moderate intermittent pain for up to week afterwards." This may avoid the patient seeking extra treatment shortly afterwards. (I suspect more research, statistics etc. may need to be gathered on post-operative pain.)
Drugs and materials etc. used should be legibly written (preferably printed) on invoices.
The dentist should be respectful of the patient's time. The dentist should not see 2 (or even more) patients at the same time. This is likely to diminish the ability to concentrate fully on one person at a time, and in some cases, may risk cross infection.
A small minority of dentists are sarcastic and verbally abusive to patients, when the latter is unable to answer back. This is unprofessional. Patients should not be berated for not seeing a dentist every 6 months, or switching dentists or refusing to have a routine x-ray.
If a quote is given beforehand, and the work is as predicted, the fee should not exceed the quote. If work takes longer than predicted, the fee should be in proportion to the quote.
Dentists vary in quality of care, a good dentist will already be doing most
or all of the things above.