Among recommendations from an increasingly vocal, new breed of dentists who are serving as watchdogs of their own business:

Compile a list of prospective dentists from talking with family, friends and colleagues, especially those with dental histories similar to yours. Ask dentists whom they use, who is best, who is most qualified in the treatment you need.

Question each prospective dentist and specialist. Check qualifications. Ask for a current re'sume' citing professional work and courses attended. (District of Columbia dentists are required to take 25 hours of continuing education each year.)

Be blunt. Ask, "Why should I come to you for treatment?"

Insist on an itemized bill and a step-by-step plan of treatment.

Some signs, according to experts, of dentists to be wary of:

* The "quick puller," who suddenly proposes major work where there's never been a hint of trouble and says it's impossible to estimate the cost.

* Doomsday prognoses: either/or alternatives and a rejection of patient suggestions.

* The "picture happy," who insists on taking X-rays every visit regardless of the last set's currency; who does not use a lead apron to protect the patient.

* The anti second opinion, who offers only one specialist as a referral and is reluctant to give patients copies of their dental records.

* Refusal to explain what is being done in a patient's mouth and a disdain for questions.

* Insistence on performing every dental procedure, whether or not it may warrant a specialist.

* Bargain-basement or penthouse prices.

Dental complaints may be addressed to the Peer Review Appeals Committee: D.C. Dental Society, Suite 202, 4300 Fordham Rd. NW 20016; Southern Maryland Dental Society, Suite 203, 7901 Annapolis Rd., Lanham 20706; Northern Virginia Dental Society, 1008 N. Randolph Rd., Arlington.