State of Minnesota, Respondent, vs. Scott Frederick Kretz, Appellant.

may not be cited except as provided by

Minn. Stat. § 480 A. 08, subd. 3 (1996).

 STATE OF MINNESOTA

 IN COURT OF APPEALS

 C6-96-2060

Kathryn M. Ogle,

Appellant,

vs.

Bassett Creek Dental, P.A.,

Respondent,

Lisa P. Howard, D.D.S., et al.,

Defendants.

 Filed June 3, 1997

 Affirmed

 Willis, Judge

Hennepin County District Court

File No. 9511264

James E. Lindell, Lowe, Schmidthuber & Lindell, LLP, 2420 Centre Village, 431 South 7th Street, Minneapolis, MN 55415 (for Appellant)

Clarance E. Hagglund, Britton D. Weimer, William C. Weeding, Hagglund & Weimer, 4000 Water Park Place, 5101 Olson Memorial Highway, Minneapolis, MN 55422 (for Respondent)

Considered and decided by Huspeni, Presiding Judge, Toussaint, Chief Judge, and Willis, Judge.

 U N P U B L I S H E D O P I N I O N

 WILLIS, Judge

Appellant Catherine Ogle brought this dental malpractice action against Bassett Creek Dental, P.A. The case was tried to the district court, which found that (1) Bassett Creek deviated both from the applicable standard of care and from their own protocol with respect to taking full-mouth x-rays and referral to a periodontist, (2) Ogle failed to care for her condition properly, and (3) Ogle failed to prove that her loss of teeth and periodontal condition resulted from Bassett Creek's deviation from the applicable standard of care. The court entered judgment in favor of Bassett Creek and this appeal followed. We affirm.

 FACTS

  Catherine Ogle became a patient at Bassett Creek in June 1989. Ogle's previous dentist, Dr. Domaas, had (1) treated her for tooth decay, (2) completed a crown, (3) referred her to an endodontist for a root canal procedure, and (4) diagnosed her with periodontal disease and referred her to a periodontist. Dr. Domaas blamed Ogle's periodontal condition, in part, on her poor oral hygiene and her smoking and candy-eating habits.

While Ogle was a patient at Bassett Creek, her periodontal disease and tooth decay worsened, and it was necessary for her to have teeth removed. Although it was part of Bassett Creek's protocol to take full-mouth x-rays of its patients on a periodic basis, they did not take such x-rays of Ogle during the five years she was a patient there. Bassett Creek referred Ogle to a periodontist in July 1994. Ogle continued to practice poor oral hygiene, to smoke, and to eat candy while she was a patient at Bassett Creek. Additionally, Ogle was taking prescription medication that caused dryness in her mouth and may have contributed to her condition.

The district court concluded that Bassett Creek deviated from the applicable standard of care in failing to refer Ogle to a periodontist before July 1994 and in failing to obtain full-mouth x-rays every three to five years. The district court also concluded that Ogle practiced poor oral hygiene, failed to keep appointments at Bassett Creek, and continued to smoke and to eat candy. Finally, the district court concluded that Ogle failed to prove by a preponderance of the evidence that Bassett Creek's deviation from the applicable standard of care caused her condition and ordered judgment in favor of Bassett Creek.

 D E C I S I O N

  Ogle argues that the district court erred in concluding that she had not shown that Bassett Creek's deviation from the applicable standard of care caused her condition because her expert's testimony that the deviation caused the condition was uncontroverted and unimpeached.

In malpractice actions, a similar general standard of care applies to dentists and medical doctors. Compare Harris v. Wood, 214 Minn. 492, 498, 8 N.W.2d 818, 821-22 (1943) (stating that dentist must exercise such reasonable care and skill as is usually exercised by dentists of good standing in community), with Weiby v. Wente, 264 N.W.2d 624, 628 (Minn. 1978) (stating that doctor must use that degree of skill, care, and knowledge used by other doctors under like circumstances in similar locality); see also 4 Minnesota Practice, CIVJIG 425 (1986) (describing duties of doctors and dentists).

To establish a prima facie case of medical malpractice for negligent treatment, a plaintiff is required to demonstrate "(1) the standard of care recognized by the medical community as applicable to the particular defendant's conduct; (2) that the defendant departed from that standard; * * * (3) that the defendant's departure from that standard was a direct cause of [the patient's] injuries;" and (4) damages. In establishing this prima facie case, the plaintiff must introduce expert testimony to establish the standard of care, the defendant's departure from that standard, and causation, when these issues are not within the common knowledge of laymen.

 Reinhardt v. Colton, 337 N.W.2d 88, 94-5 (Minn. 1983) (citation omitted); see also Ellering v. Gross, 189 Minn. 68, 70, 72, 248 N.W. 330, 330-31 (1933) (recognizing that expert testimony is generally necessary in dental malpractice action).

Medical expert testimony is not conclusive and may be disregarded in whole or in part unless the expert's opinions are

"so positive as to exclude all doubt as to the matter on which they are given and unless based on testimony which is positive, consistent, unimpeached, and uncontradicted."

 Barrera v. Muir, 553 N.W.2d 104, 107 (Minn. App. 1996), review denied (Minn. Oct. 29, 1996) (citation omitted).

Ogle's expert, Dr. Winters, testified that Bassett Creek's deviation from the applicable standard of care and its own protocol for x-rays delayed the diagnosis of Ogle's problems and that its delay in referring her to a periodontist led to her loss of teeth. However, there is also evidence that Ogle's condition existed before her treatment at Bassett Creek and that her own behavior contributed to her condition. Ogle's former dentist, Dr. Domaas, testified that her poor oral hygiene, smoking, and candy eating contributed to her periodontal condition. Dr. Michaelis, a dentist who examined Ogle in November 1994, concluded that inadequate home care caused Ogle's periodontal condition. Dr. Winter's testimony was not so positive as to exclude all doubt. See id. (concluding that expert testimony was not so positive as to exclude all doubt where experts disagreed on diagnosis, prognosis, and degree of impairment and that jury was therefore free to disregard experts' opinions).

The district court was not bound by Dr. Winter's testimony, and the evidence supports its conclusion that Ogle failed to show that Bassett Creek's deviation from the applicable standard of care was the direct cause of her condition.

  Affirmed.