0099-2399/90/1608-0387/$02.00/0 JOURNAL OF ENDODONTICS Copyright 9 1990 by The American Association of Endodontists
Printed in U.S.A. VOL. 16, NO. 8, AUGUST 1990
CLINICAL ARTICLES Understanding Informed Consent and Its Relationship to the Incidence of Adverse Treatment Events in Conventional Endodontic Therapy Alan G. Selbst, DMD, MS, FACD
context could be preparation or treatment of a tooth for which specific consent was not obtained. A cause of action may also accrue if the dentist exceeds the limits of the consent granted by the patient by performing additional procedures not authorized by the patient while performing the consented procedure (3). Negligence theory is based on the liability of the dentist for failure to disclose the risks of and alternatives to treatment. As doctors, we occupy a position of high trust and special knowledge and we owe our patients a duty to inform them and advise them. It is important not to "withhold any facts which are necessary to form the basis of an intelligent consent by the patient to the proposed treatment" (4). What constitutes legally sufficient informed consent? Unfortunately, there is not a common standard applied in all jurisdictions. The theories frequently articulated are the "reasonable doctor standard" and the "patient need standard."
Forty-three endodontic specialists recorded the occurrence of all adverse treatment events in 3308 consecutive conventional endodontic cases. Statistical analysis confirmed that retreatment cases and mid-treatment referral cases have a greater incidence of adverse treatment events. Since the doctrine of informed consent requires that the doctor inform the patient of reasonably foreseeable consequences of treatment, it is therefore important that the endodontist be cognizant of such events and decide what information is appropriate for disclosure. Since jurisdictional differences exist in the interpretation of what constitutes sufficient informed consent, it is important that local groups investigate the statutes in their state and construct reasonable informed consent documents.
REASONABLE DOCTOR STANDARD Dental malpractice litigation has increased significantly in the last few years. The incidence ofendodontic malpractice claims as reported by The Dentist's Insurance Company of California in March 1986 indicated that endodontic claims are the most frequently filed malpractice claims (1). Recently, litigation has increased in the area of "negligent non-disclosure," an action claiming the lack of informed consent. In this scenario, the dentist does everything right technically; however, he may be found negligent if he failed to inform the patient of the inherent risks of the procedure and one of those risks manifests itself. These claims may be increasing because in many states the issue of what is reasonable informed consent does not require the plaintiffto procure expensive expert testimony. This reduces the cost of litigation and thus smaller claims become practical to pursue by an attorney and plaintiff. The doctrine of informed consent has evolved from two areas of the law: battery and negligence. In this context, "any unauthorized touching of the person of another.., constitutes assault and battery" (2). Examples of battery in a dental
The practitioner will be liable for failing to disclose the same risks about treatment that another reasonable and prudent practitioner would disclose under the same or similar circumstances. The reasonable doctor standard requires that the patient produce expert testimony to prove that the doctor failed to disclose sufficient information (5). Common criticisms of this method are that it is increasingly costly to provide such testimony and that this method fails to take into consideration the variability of patients and their individual needs for information. THE PATIENT NEED STANDARD The patient need standard is based on the argument that the patient has an inherent right of self-determination. The patient need standard is subdivided and uses two standards to measure the sufficiency of disclosure. The first standard is the objective standard. The objective standard measures what a reasonable patient needs to know about a procedure, when
387
388
Journal of Endodontics
Selbst
viewed from the standpoint of a reasonable juror. The second standard is the subjective standard, and it does not measure disclosure by the reasonable standard. The subjective standard measures what would be material to the patient's treatment decision based upon that individual patient's needs. The reasonable patient or objective standard is applied in the majority of jurisdictions and was articulated in the case of Canterbury v. Spence. Under the reasonable patient standard, the doctor has the duty to disclose all material risks of treatment. Canterbury held that "a risk is thus material when a reasonable person, in what the physician knows or should know to be the patient's position, would be likely to attach significance to the risk or cluster or risks in deciding whether or not to forego the proposed therapy" (6). The court adopted an "objective standard" for determining what risks are material and rejected the "subjective standard" which would require the "physician to second-guess the patient, whose ideas on materiality could hardly be known to the physician" (7). However, some jurisdictions apply the subjective standard to measure what information needs to be disclosed to the patient about the intended procedure. Problems associated with the subjective adequacy of informed consent arise because a patient's need to know may vary. In Scott v. Bradford, the court adopted the "subjective standard" of materiality (8). The difficulty with this decision and its application is that it permits the patient to retrospectively claim that the untoward event, even if it would not be material to the reasonable person, would have been material to him had he known the risk prior to the procedure. It has been argued that the application of this subjective standard places an excessive burden on the health care provider. E L E M E N T S OF D I S C L O S U R E The typical common law elements of disclosure are: 1. the nature of the procedure 2. the inherent risks of the procedure 3. the alternatives to the procedure 4. the anticipated benefits of the procedure (9). It has been suggested that the following be disclosed: 5. disclosure of the inherent risks of the alternative procedures. 6. a generalized opportunity to question the doctor about any of the above mentioned elements (10, 11).
collection of data. All participants were engaged in the limited practice of endodontics and were either board-qualified or board-certified endodontists. Participation in the study was open to all members. Members were provided with data collection forms which identified twenty-eight anticipated risks and provided space for the listing of additional treatment events. The participants were instructed to identify all treatment events by recording on each consecutive patient all subjective and objective experiences during their endodontic treatment. Each clinician also identified unanticipated procedural events. RESULTS Evaluation of 2988 cases comprising the category Initial Case allows us predict the occurrence of each of the 28 specified complications within the designated ranges with a confidence level of 95% (Table 1). Among the groups Initial, Retreatment, and Mid-treatment, the data were sufficient to permit statistical analysis of 10 of the 28 categories of treatment complications listed in Table 1. These 10 categories are listed in Table 2 and were statistically analyzed for differences at the p = 0.05 level using the chi-square method. The following groups were analyzed: initial treatment g r o u p - - n o prior endodontic intervention, endodontics initiated and completed by endodontist, total = 2988; retreatment group--formed by combining three groups (paste, gutta-percha, and silver cone retreats), total = 110; and mid-treatment referral group--endodontic treatment initiated by another dentist and referred to endodontist, total -101. There was a statistically significant increased incidence of total complications in both retreatment and mid-treatment cases when compared with the occurrence of complications in initial cases. Specifically, retreatment cases had a significant increased incidence of underfill, perforation, and swelling. Mid-treatment cases had a significant increase in the incidence of broken instruments, overfill, and perforation. The percentage occurrence of nine specific treatment complications is shown in Fig. 1. Comparing total complications encountered among the three groups, our data indicate that some treatment complication will occur approximately twice as frequently in retreatment and mid-treatment cases as in initial cases (Fig. 2). DISCUSSION
P U R P O S E AND M E T H O D It was the intent of the Southwest Society of Endodontists to identify and quantify the inherent risks associated with conventional endodontic treatment. Since modern endodontic practice encompasses a variety of case scenarios, categories were selected to segregate these cases. Accordingly, endodontic cases were divided into eight groups: 1, initial treatment: initiated and completed by an endodontist; 2, retreatment of paste fill; 3, retreatment of silver cone fill; 4, retreatment of gutta-percha fill; 5, retreatment of root canal done by endodontist; 6, mid-treatment referral; 7, cracked tooth syndrome; and 8, endo-perio case. Of the 105 members of the Southwest Society of Endodontists, 43 members participated in the
The intent of this study was to accumulate data on the incidence of treatment events encountered by a geographically and educationally diverse cross-section of the practicing endodontic community. We wanted to avoid single operator and single institution biases by enlisting the participation of many clinicians. Furthermore, we wanted to avoid a retrospective study and dependence on historical and stale patient records. We required that the data be collected on current and consecutive patients who could be contemporaneously assessed with reference to treatment events. We believe this method of continuous assessment provided more consistent reports between, for example, degree of pain or swelling. Additional questions were raised by our investigation. A1-
Vol. 16, No. 8, August 1990
Informed Consent/Treatment Events
389
TABLE 1. SSE-Survey: listed below are the upper and lower limits for each treatment category in the "initial" treatment group
Category Broken instrument Root fracture Overfills Underfills Perforations Treatment (additional tooth) Paresthesia Trismus Hematoma Discoloration Syncope Tachycardia Inadequate anesthesia Slight pain Moderate pain Severe pain Additional swelling Tissue injury Lost temporary Aspiration Damage (crown) Allergy to medicine Side effect (medicine) Leaking restoration Periodontal complication Resorption Calcifications Fractures
Lower Limit (%)
Calculated (%)
Upper Limit (%)
0.66 0.05 3.54 2.03 0.50 0.46 0.04 0.09 0.05 0.01 0.00 0.02 1.97 3.65 3.02 0.37 1.17 0.02 0.46
0.971 0.167 4.15 2.544 0.770 0.736 0.134 0.234 0.167 0.067 0.033 0.1 2.477 4.284 3.548 0.602 1.573 0.100 0.736 None recorded 0.301 0.067 0.301 0.736 1.673 0.502 1.037 0.301
1.39 0.44 4.18 3.10 1.14 1.1 0.40 0.52 0.44 0.37 0.33 0.37 3.02 4.32 3.58 0.94 2.08 0.37 1.10
0.14 0.01 0.14 0.46 1.24 0.28 0.72 0.14
TABLE 2. Statistical analysis of 10 categories
Treatment Event
Initial
Broken instrument Overfill Underfill Perforation Slight pain Moderate pain Severe pain Inadequate anesthesia Additional swelling Total complications
Retreatment
0.60 0.37 0.60 1.10 2.21 0.84 1.48 0.60
SOUTHWEST SOCIETY OF ENDODONTISTS TREATMENT COMRJCATIONS
Mid-Treatment
aEIREAT
V r
~
I".'."-"-t
B m m
* Indicates statistically significant difference. OVEaRL~ UU0C~=~Las
su6~rt
~.aA~E
se*lmE I~r
~r
COMRJCATIONS
though it is commonly accepted that retreatment cases are fraught with complications, there has been little data to substantiate this assumption. Figure 2 depicts the incidence of treatment events by category and as such indicates that 42% of retreatment cases experience an adverse treatment event. We attempted to accumulate data on retreatment of paste fills versus other types of retreatments and although raw data indicated paste fills had a 78% incidence of adverse treatment events, the sample size was too small for statistical comparison. We will need to accumulate more data in order to adequately assess and compare the incidence of treatment events in the various types of retreatment cases endodontists are called upon to treat. Because adequate informed consent should ideally use statistics that are relevant to the particular
FIG 1. Southwest Society of Endodontists: treatment complications.
case type, more data need to be accumulated for the various types of retreatment cases. As a general rule, the treating practitioner has the duty to disclose to his patient reasonablyforseeable risks of treatment. The endodontist should be cognizant of the following additional facts. Informed consent is a nondelegable duty. Only the doctor can obtain informed consent from the patient. Informed consent is invalid if the patient does not understand what you have told him, therefore, use reasonable means to assess the patient's understanding; ask questions.
390
Selbst
Journal of Endodontics
SOUTHWEST SOCIETY OF ENDODONTISTS TOTAL TREATMENT COMPLICATIONS
AL CASES20.9%
38.6%
tic treatment in fewer than 5 % of initial cases. 4. The patient may experience swelling in fewer than 2% of initial cases. 5. The patient may have damage to the existing crown or restoration as a result of endodontic intervention in fewer than 0.5% of cases. Of particular interest are the data suggesting an increased incidence of complications associated with retreatment cases, particularly the retreatment of paste fills. Why these cases demonstrate more than twice the incidence of reportable "events" is subject to speculation and further investigation. Nevertheless, it might be advisable to inform retreatment patients that their incidence of treatment events is higher than those expected in normal cases.
REFERRAL
FIG 2. Southwest Society of Endodontists: total treatment complications.
We believe this information will aid our fellow endodontists as we attempt to comply with the doctrine of informed consent in our various jurisdictions. It is advisable that you research the relevant state statutes, case law, and obtain legal counsel in developing informed consent forms. CONCLUSIONS It is concluded that the following events needed to be disclosed and discussed with endodontic patients: 1. Endodontic therapy cannot be guaranteed and some teeth may be lost irrespective of endodontic intervention. 2. Overfill or underfill of the root canal may occur in fewer than 5% of initial cases. 3. The patient may experience pain attendant on endodon-
I would like to express my deep appreciation to Dr. Michael Wang, Dr. Johnny Cailletau, and David Selbst for their assistance in data entry and statistical analysis. Additionally, I would thank the dedicated and conscientious members of the Southwest Society of Endodontists whose participation made this study possible. Dr. Selbst is in private practice in Houston, TX.
References 1. The Dentist's Insurance Company Newsletter, March 1966, Sacramento, California. 2. Mohr v. Williams, 95 Minn 261,104 N.W. 12 (1905). 3. Barnett v. Bachrach, (Mun.App.D.C. 1943) 34 A.2d 626. 4. Natanson v. Kline, 186 Kan. 393, 350 P.2d 1093 (1960). 5. Wilson v. Scott, 412 S.W.2d 299 (Tex. 1967). 6. Canterbury v. Spence, 464 F.2d 787 (D.C. Cir.) cert. denied, 409 U.S. 1064 (1972). 7. Id. at 787 8. Scott v. Bradford, 606 P.2d 554 (Okla. 1979). 9. Meisel & Roth, Toward and Informed Discussion of Informed Consent: A review and Critique of the Empirical Studies, 25 Ariz L. Rev 265, 296, n.158 (1983). 10. Waltz & Scheuneman, Informed Consent to Therapy, 64 Nw U. L. Rev. 628, 629 (1970). 11. CommuniqueAmerican Association of Endodontists, Vol 3, July 1986.
Printed in U.S.A. VOL. 16, NO. 8, AUGUST 1990
CLINICAL ARTICLES Understanding Informed Consent and Its Relationship to the Incidence of Adverse Treatment Events in Conventional Endodontic Therapy Alan G. Selbst, DMD, MS, FACD
context could be preparation or treatment of a tooth for which specific consent was not obtained. A cause of action may also accrue if the dentist exceeds the limits of the consent granted by the patient by performing additional procedures not authorized by the patient while performing the consented procedure (3). Negligence theory is based on the liability of the dentist for failure to disclose the risks of and alternatives to treatment. As doctors, we occupy a position of high trust and special knowledge and we owe our patients a duty to inform them and advise them. It is important not to "withhold any facts which are necessary to form the basis of an intelligent consent by the patient to the proposed treatment" (4). What constitutes legally sufficient informed consent? Unfortunately, there is not a common standard applied in all jurisdictions. The theories frequently articulated are the "reasonable doctor standard" and the "patient need standard."
Forty-three endodontic specialists recorded the occurrence of all adverse treatment events in 3308 consecutive conventional endodontic cases. Statistical analysis confirmed that retreatment cases and mid-treatment referral cases have a greater incidence of adverse treatment events. Since the doctrine of informed consent requires that the doctor inform the patient of reasonably foreseeable consequences of treatment, it is therefore important that the endodontist be cognizant of such events and decide what information is appropriate for disclosure. Since jurisdictional differences exist in the interpretation of what constitutes sufficient informed consent, it is important that local groups investigate the statutes in their state and construct reasonable informed consent documents.
REASONABLE DOCTOR STANDARD Dental malpractice litigation has increased significantly in the last few years. The incidence ofendodontic malpractice claims as reported by The Dentist's Insurance Company of California in March 1986 indicated that endodontic claims are the most frequently filed malpractice claims (1). Recently, litigation has increased in the area of "negligent non-disclosure," an action claiming the lack of informed consent. In this scenario, the dentist does everything right technically; however, he may be found negligent if he failed to inform the patient of the inherent risks of the procedure and one of those risks manifests itself. These claims may be increasing because in many states the issue of what is reasonable informed consent does not require the plaintiffto procure expensive expert testimony. This reduces the cost of litigation and thus smaller claims become practical to pursue by an attorney and plaintiff. The doctrine of informed consent has evolved from two areas of the law: battery and negligence. In this context, "any unauthorized touching of the person of another.., constitutes assault and battery" (2). Examples of battery in a dental
The practitioner will be liable for failing to disclose the same risks about treatment that another reasonable and prudent practitioner would disclose under the same or similar circumstances. The reasonable doctor standard requires that the patient produce expert testimony to prove that the doctor failed to disclose sufficient information (5). Common criticisms of this method are that it is increasingly costly to provide such testimony and that this method fails to take into consideration the variability of patients and their individual needs for information. THE PATIENT NEED STANDARD The patient need standard is based on the argument that the patient has an inherent right of self-determination. The patient need standard is subdivided and uses two standards to measure the sufficiency of disclosure. The first standard is the objective standard. The objective standard measures what a reasonable patient needs to know about a procedure, when
387
388
Journal of Endodontics
Selbst
viewed from the standpoint of a reasonable juror. The second standard is the subjective standard, and it does not measure disclosure by the reasonable standard. The subjective standard measures what would be material to the patient's treatment decision based upon that individual patient's needs. The reasonable patient or objective standard is applied in the majority of jurisdictions and was articulated in the case of Canterbury v. Spence. Under the reasonable patient standard, the doctor has the duty to disclose all material risks of treatment. Canterbury held that "a risk is thus material when a reasonable person, in what the physician knows or should know to be the patient's position, would be likely to attach significance to the risk or cluster or risks in deciding whether or not to forego the proposed therapy" (6). The court adopted an "objective standard" for determining what risks are material and rejected the "subjective standard" which would require the "physician to second-guess the patient, whose ideas on materiality could hardly be known to the physician" (7). However, some jurisdictions apply the subjective standard to measure what information needs to be disclosed to the patient about the intended procedure. Problems associated with the subjective adequacy of informed consent arise because a patient's need to know may vary. In Scott v. Bradford, the court adopted the "subjective standard" of materiality (8). The difficulty with this decision and its application is that it permits the patient to retrospectively claim that the untoward event, even if it would not be material to the reasonable person, would have been material to him had he known the risk prior to the procedure. It has been argued that the application of this subjective standard places an excessive burden on the health care provider. E L E M E N T S OF D I S C L O S U R E The typical common law elements of disclosure are: 1. the nature of the procedure 2. the inherent risks of the procedure 3. the alternatives to the procedure 4. the anticipated benefits of the procedure (9). It has been suggested that the following be disclosed: 5. disclosure of the inherent risks of the alternative procedures. 6. a generalized opportunity to question the doctor about any of the above mentioned elements (10, 11).
collection of data. All participants were engaged in the limited practice of endodontics and were either board-qualified or board-certified endodontists. Participation in the study was open to all members. Members were provided with data collection forms which identified twenty-eight anticipated risks and provided space for the listing of additional treatment events. The participants were instructed to identify all treatment events by recording on each consecutive patient all subjective and objective experiences during their endodontic treatment. Each clinician also identified unanticipated procedural events. RESULTS Evaluation of 2988 cases comprising the category Initial Case allows us predict the occurrence of each of the 28 specified complications within the designated ranges with a confidence level of 95% (Table 1). Among the groups Initial, Retreatment, and Mid-treatment, the data were sufficient to permit statistical analysis of 10 of the 28 categories of treatment complications listed in Table 1. These 10 categories are listed in Table 2 and were statistically analyzed for differences at the p = 0.05 level using the chi-square method. The following groups were analyzed: initial treatment g r o u p - - n o prior endodontic intervention, endodontics initiated and completed by endodontist, total = 2988; retreatment group--formed by combining three groups (paste, gutta-percha, and silver cone retreats), total = 110; and mid-treatment referral group--endodontic treatment initiated by another dentist and referred to endodontist, total -101. There was a statistically significant increased incidence of total complications in both retreatment and mid-treatment cases when compared with the occurrence of complications in initial cases. Specifically, retreatment cases had a significant increased incidence of underfill, perforation, and swelling. Mid-treatment cases had a significant increase in the incidence of broken instruments, overfill, and perforation. The percentage occurrence of nine specific treatment complications is shown in Fig. 1. Comparing total complications encountered among the three groups, our data indicate that some treatment complication will occur approximately twice as frequently in retreatment and mid-treatment cases as in initial cases (Fig. 2). DISCUSSION
P U R P O S E AND M E T H O D It was the intent of the Southwest Society of Endodontists to identify and quantify the inherent risks associated with conventional endodontic treatment. Since modern endodontic practice encompasses a variety of case scenarios, categories were selected to segregate these cases. Accordingly, endodontic cases were divided into eight groups: 1, initial treatment: initiated and completed by an endodontist; 2, retreatment of paste fill; 3, retreatment of silver cone fill; 4, retreatment of gutta-percha fill; 5, retreatment of root canal done by endodontist; 6, mid-treatment referral; 7, cracked tooth syndrome; and 8, endo-perio case. Of the 105 members of the Southwest Society of Endodontists, 43 members participated in the
The intent of this study was to accumulate data on the incidence of treatment events encountered by a geographically and educationally diverse cross-section of the practicing endodontic community. We wanted to avoid single operator and single institution biases by enlisting the participation of many clinicians. Furthermore, we wanted to avoid a retrospective study and dependence on historical and stale patient records. We required that the data be collected on current and consecutive patients who could be contemporaneously assessed with reference to treatment events. We believe this method of continuous assessment provided more consistent reports between, for example, degree of pain or swelling. Additional questions were raised by our investigation. A1-
Vol. 16, No. 8, August 1990
Informed Consent/Treatment Events
389
TABLE 1. SSE-Survey: listed below are the upper and lower limits for each treatment category in the "initial" treatment group
Category Broken instrument Root fracture Overfills Underfills Perforations Treatment (additional tooth) Paresthesia Trismus Hematoma Discoloration Syncope Tachycardia Inadequate anesthesia Slight pain Moderate pain Severe pain Additional swelling Tissue injury Lost temporary Aspiration Damage (crown) Allergy to medicine Side effect (medicine) Leaking restoration Periodontal complication Resorption Calcifications Fractures
Lower Limit (%)
Calculated (%)
Upper Limit (%)
0.66 0.05 3.54 2.03 0.50 0.46 0.04 0.09 0.05 0.01 0.00 0.02 1.97 3.65 3.02 0.37 1.17 0.02 0.46
0.971 0.167 4.15 2.544 0.770 0.736 0.134 0.234 0.167 0.067 0.033 0.1 2.477 4.284 3.548 0.602 1.573 0.100 0.736 None recorded 0.301 0.067 0.301 0.736 1.673 0.502 1.037 0.301
1.39 0.44 4.18 3.10 1.14 1.1 0.40 0.52 0.44 0.37 0.33 0.37 3.02 4.32 3.58 0.94 2.08 0.37 1.10
0.14 0.01 0.14 0.46 1.24 0.28 0.72 0.14
TABLE 2. Statistical analysis of 10 categories
Treatment Event
Initial
Broken instrument Overfill Underfill Perforation Slight pain Moderate pain Severe pain Inadequate anesthesia Additional swelling Total complications
Retreatment
0.60 0.37 0.60 1.10 2.21 0.84 1.48 0.60
SOUTHWEST SOCIETY OF ENDODONTISTS TREATMENT COMRJCATIONS
Mid-Treatment
aEIREAT
V r
~
I".'."-"-t
B m m
* Indicates statistically significant difference. OVEaRL~ UU0C~=~Las
su6~rt
~.aA~E
se*lmE I~r
~r
COMRJCATIONS
though it is commonly accepted that retreatment cases are fraught with complications, there has been little data to substantiate this assumption. Figure 2 depicts the incidence of treatment events by category and as such indicates that 42% of retreatment cases experience an adverse treatment event. We attempted to accumulate data on retreatment of paste fills versus other types of retreatments and although raw data indicated paste fills had a 78% incidence of adverse treatment events, the sample size was too small for statistical comparison. We will need to accumulate more data in order to adequately assess and compare the incidence of treatment events in the various types of retreatment cases endodontists are called upon to treat. Because adequate informed consent should ideally use statistics that are relevant to the particular
FIG 1. Southwest Society of Endodontists: treatment complications.
case type, more data need to be accumulated for the various types of retreatment cases. As a general rule, the treating practitioner has the duty to disclose to his patient reasonablyforseeable risks of treatment. The endodontist should be cognizant of the following additional facts. Informed consent is a nondelegable duty. Only the doctor can obtain informed consent from the patient. Informed consent is invalid if the patient does not understand what you have told him, therefore, use reasonable means to assess the patient's understanding; ask questions.
390
Selbst
Journal of Endodontics
SOUTHWEST SOCIETY OF ENDODONTISTS TOTAL TREATMENT COMPLICATIONS
AL CASES20.9%
38.6%
tic treatment in fewer than 5 % of initial cases. 4. The patient may experience swelling in fewer than 2% of initial cases. 5. The patient may have damage to the existing crown or restoration as a result of endodontic intervention in fewer than 0.5% of cases. Of particular interest are the data suggesting an increased incidence of complications associated with retreatment cases, particularly the retreatment of paste fills. Why these cases demonstrate more than twice the incidence of reportable "events" is subject to speculation and further investigation. Nevertheless, it might be advisable to inform retreatment patients that their incidence of treatment events is higher than those expected in normal cases.
REFERRAL
FIG 2. Southwest Society of Endodontists: total treatment complications.
We believe this information will aid our fellow endodontists as we attempt to comply with the doctrine of informed consent in our various jurisdictions. It is advisable that you research the relevant state statutes, case law, and obtain legal counsel in developing informed consent forms. CONCLUSIONS It is concluded that the following events needed to be disclosed and discussed with endodontic patients: 1. Endodontic therapy cannot be guaranteed and some teeth may be lost irrespective of endodontic intervention. 2. Overfill or underfill of the root canal may occur in fewer than 5% of initial cases. 3. The patient may experience pain attendant on endodon-
I would like to express my deep appreciation to Dr. Michael Wang, Dr. Johnny Cailletau, and David Selbst for their assistance in data entry and statistical analysis. Additionally, I would thank the dedicated and conscientious members of the Southwest Society of Endodontists whose participation made this study possible. Dr. Selbst is in private practice in Houston, TX.
References 1. The Dentist's Insurance Company Newsletter, March 1966, Sacramento, California. 2. Mohr v. Williams, 95 Minn 261,104 N.W. 12 (1905). 3. Barnett v. Bachrach, (Mun.App.D.C. 1943) 34 A.2d 626. 4. Natanson v. Kline, 186 Kan. 393, 350 P.2d 1093 (1960). 5. Wilson v. Scott, 412 S.W.2d 299 (Tex. 1967). 6. Canterbury v. Spence, 464 F.2d 787 (D.C. Cir.) cert. denied, 409 U.S. 1064 (1972). 7. Id. at 787 8. Scott v. Bradford, 606 P.2d 554 (Okla. 1979). 9. Meisel & Roth, Toward and Informed Discussion of Informed Consent: A review and Critique of the Empirical Studies, 25 Ariz L. Rev 265, 296, n.158 (1983). 10. Waltz & Scheuneman, Informed Consent to Therapy, 64 Nw U. L. Rev. 628, 629 (1970). 11. CommuniqueAmerican Association of Endodontists, Vol 3, July 1986.
