Psychological Stress Reduction During Dental Procedures NORMAN L. CORAH, ELLIOT N. GALE and STEPHEN J. ILLIG Departments of Behavioral Science and Restorative Dentistry, State University of New York at Buffalo, 4510 Main St., Buffalo, New York 14226
Behavioral methods of patient stress reduction during amalgam restorations were evaluated. Eighty adult patients were randomly assigned to one of four groups of 20 each: a control group, a relaxation group, a perceived control group, and an active distraction group. Both relaxation and distraction were found to be effective in reducing patient discomfort.
J Dent Res 58(4) :1347-1351, April 1979
Introduction. Patient stress or anxiety during dental treatment has been of major concern to dentists.1'2 In addition, anxiety appears to be an important component in the perception of pain. Wolff has maintained that affective components such as anxiety must be present for the experience of pain and that these components are largely based on learning.3 Many behaviorally-oriented suggestions for reducing stress have been given in the literature. However, there has been little or no systematic research on comparing or evaluating their effectiveness. These suggestions appear to fall into three broad categories: perceived control, distraction and relaxation. Lazarus has suggested that the individual's sense of control over a potentially aversive situation is an important element in the stress experience.4 Presumably, an individual will appraise such a situation as less threatening if he perceives himself as having some measure of control over the aversive stimulus. Most of the research in this area has been conducted in laboratory settings.
Received for publication June 9, 1978. Accepted for publication June 30, 1978. This investigation was supported in part by USPHS Research Grant DE-04494 from the National Institutes of Health, Bethesda, Maryland, 20014.
While many studies have shown that perceived control paradigms may be somewhat effective in reducing stress, the results tend to be rather mixed. It appears that, in some instances, control options can actually increase stress.5 If the results of studies conducted in a dental setting are considered, the picture is also a mixed one, with both positive and negative effects of control having been found.6'7 However, we felt that perceived control should be evaluated in the context of other methods of stress reduction. Patient distraction has often been mentioned as a means of alleviating anxiety and pain.8 Although there appears to be a strong belief in the efficacy of distraction, there is little evidence to support it. A few studies of pain tolerance have shown this technique to be successful, especially if it is combined with other variables such as suggestion or perceived control.9 10'11 There appears to be no work which has evaluated the effects of distraction on anxiety or stress responses. Our study was designed to evaluate a method of distraction in the dental context. Behavioral methods of relaxation have also been recommended as useful techniques for reducing dental stress. The basis for these techniques rests on the principle that it is impossible to be relaxed and anxious at the same time.12 Relaxation in the context of desensitization therapy has been shown to be very effective with dental phobics.13 However, this procedure is conducted outside of the feared context using the patient's imagination and requires several sessions to be successful. Successfully treated phobics are then able to undergo the required dental treatment. Our concern is with the patient who is able to approach dental treatment but finds it stressful. Therefore, we have attempted to evaluate a method of relaxing the patient during dental treatment. 1347
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CORAHETAL.
Our study evaluated three approaches to reducing patient anxiety and stress during dental treatment. The dental treatment selected was the Class II amalgam restoration because it is the most common restorative procedure.
Materials and methods. The subjects were 80 adult dental patients, 50 men and 30 women, who required a minimum of two Class II amalgam restorations. The patients were acquired from three different sources: the dental school admissions clinic, a preventive dentistry clinic operated for university students, and mass media reports through which patients heard about our research. A clinical examination and restorations, if necessary, were provided free of charge as an inducement for patients to participate. The patients ranged in age from 18 to 65 years with an average of 26.75 years. The design of the study was a mixedgroups-by-visit design, in which all patients received a normal restoration on the first visit with assessment of their response. On the second visit, the appropriate experimental condition was introduced for the second restoration. The patients were randomly assigned to one of four groups of 20 each on the second visit, with the restriction of maintaining approximately the same proportion of men and women in each group. The first group was a control group which received dental treatment in the same way on both visits without any technique being introduced on the second visit. The second group was the relaxation group. At the second visit, these patients wore earphones and listened to tape-recorded instructions for relaxation. The recorded voice was soft-spoken, slow and somewhat repetitive. The instructions differed from the usual technique in that patients were not told to alternately tense and relax muscle groups because the tensing of muscles might interfere with the dental procedure. Therefore, the instructions stressed the relaxation of various muscle groups with the exception of the jaw muscles. The presentation was begun three to four minutes before the dentist administered anesthesia and continued until the dental procedure was completed.
J Deti t Res April 1 9 79
The third group involved the perceived control condition. The patient was given a button switch to hold in his hand during the dental procedure. He was told that it would permit him to communicate with the dentist or have the dentist stop for a moment if the patient felt the need for a rest. The button turned on a red light and sounded a buzzer when activated. A demonstration was provided prior to the beginning of the dental procedure. The distraction group was involved in an active task. The patient played a video ping pong game "against the house." The television monitor was mounted near the ceiling for comfortable viewing bv the reclining patient. A small box was clamped to the arm of the dental chair and contained the "joy stick" control for the game and a small reset button to begin a new game. Scoring for the patient and the "house" was indicated on opposite sides of the video screen. The patient was instructed that he could play the game throughout the entire dental procedure. The patient signed a consent form at the beginning of his first visit. He then filled out the Corah Dental Anxiety Scale, the Rotter Locus of Control Scale and the Need for Social Approval Scale.14,15,16 Silver-silver chloride electrodes were taped over cornpads filled with electrode jelly and attached to the palmar surface of the distal phalanges of the first and third fingers of the non-preferred hand. These electrodes were used for recording the electrodermal response (EDR). A digital strain gauge was placed on the second finger for recording heart rate (HR). The patient was then taken to the dental operatory, seated, and the electrodes and strain gauge were plugged into their connectors. Physiological recording and video monitoring took place in a room adjacent to the dental operatory. EDRs and HR were recorded throughout the dental procedure. At the end of the first session and after the patient had left the operatory, he was asked to rate his level of discomfort during the procedure on a seven-point scale ranging from Calm, Relaxed to Tense-Upset. The dentist also rated the patient on the same scale. In general, an attempt was made to have the two dental appointments one week apart. In 15 cases, the interval was two weeks; in three cases, the interval was one
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Vol 58 No 4
STRESS REDUCTION DURING DENTAL PROCEDURES
day. The appropriate condition was then introduced when the patient returned for the second visit. At the end of the second dental procedure, the patient again rated himself on the seven-point scale of discomfort (as did the dentist) and was asked a series of questions relating to his attitudes and feelings about the procedures. The patient was then debriefed and had the entire study explained, and all questions were answered. In the event that further dental work was required, appropriate referrals were made. Analyses of variance were conducted on all measures obtained from the first visit, including age, for the four groups. All F ratios were less than 1.00, indicating that the four groups were comparable on these measures.
Results. Rating Data. All analyses were made in terms of Group x Dental Anxiety x Visit. All groups were divided into high and low dental anxiety on the basis of a median split. The median score was nine. Where more than one person achieved this score in a given group, assignment to high or low dental anxiety groups was achieved by ran-
dom assignment. All analyses of patient discomfort were mixed analyses of variance with one within-subject dimension (visit). The implicit hypothesis for these data was that the change in ratings from visit one to visit two would differ in the various groups. The analysis of patient self-ratings of discomfort yielded four significant effects. There was a main effect for Dental Anxiety (F = 15.01, df = 1/72, P < 0.005), which indicated that high anxiety patients gave higher discomfort ratings (mean = 3.52) than low anxiety patients (mean = 2.50). There was also a significant main effect for Visit (F = 7.50, df = 1/72, P < 0.05), which indicated higher discomfort ratings for the first visit (mean = 3.20) than for the second visit (mean= 2.82). There was a significant Group x Visit interaction (F = 3.23, df = 3/72, P < 0.05), which is of more interest in the present study. The difference between the means (Visit 1 - Visit 2) for each group was tested by the "critical difference" method.17 The differences between the means for each
1349
group were as follows: Control, 0.0; Relaxation, .80; Perceived Control, -.10; Distraction, .80. Only the differences in the Relaxation and Distraction groups were significant (P < 0.05). These results indicate that the patients in these two groups rated themselves as experiencing less discomfort during the second visit than during the first visit. There was also a significant triple interaction among Group x Dental Anxiety x Visit (F = 5.28, df = 3/72, P < 0.005), which was similar to the Group x Visit interaction. With the smaller cell size, the difference between visit one and visit two was significant (P < 0.05) only for the high anxiety patients in the Relaxation and Distraction groups. These results suggest that, as far as self ratings are concerned, the relaxation and distraction conditions were especially effective with the high dentally anxious patients. The dentist's ratings of patient discomfort were somewhat similar to those of the patients themselves. There were two signifia main effect for Visit (F = cant effects 15.72, df = 1/72, P < 0.001), and the Group x Visit interaction (F = 3.48, df = 3/72, P < 0.05). The differences between the means (Visit 1 - Visit 2) for the different groups were: Control, -.05; Relaxation, 1.35; Perceived Control, .50; Distraction, .65. Again, the ratings of patient discomfort made by the dentist were significantly lower on the second visit for only the Relaxation and Distraction groups (P < 0.05). A third rating included for analysis was based on a question on the final rating sheet. Patients were asked which visit they liked better - the first or second - and why. Their answers were keyed 1, 2, or 3 on the following criteria. They were given a 1 if they said they preferred the first session, a 2 if they said they were the same or that there was no difference, and a 3 if they clearly preferred the second session. These scores were then subjected to a Group x Dental Anxiety analysis of variance. A significant effect was obtained for Groups (F = 2.79, df = 1/72, P < 0.05). The means obtained for the groups were: Control, 2.00; Relaxation, 2.60; Perceived Control, 2.35; Distraction, 2.70. A Duncan's Multiple Range Test was applied to these means.18 The means for the Relaxation and Distraction groups were significantly different (P < 0.05) from the Control group, indi-
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J Deti t Res April 1 9 79
CORAHETAL.
cating greater preference of those two groups for the experimental treatment visit. No other comparisons were significant. Patients were asked a number of openended questions at the conclusion of the second visit. Two of them were directly related to what they thought of the particular technique that had been introduced into the second visit. Three project staff members independently categorized these answers from the patients in the three experimental groups as to whether the patient liked the procedure or disliked the procedure. Disagreement among the raters as to classification ranged from one to two cases. In these few instances, the category agreed upon by two of the three raters was used. The frequencies are shown in the Table. TABLE FREQUENCY OF PATIENT PREFERENCES FOR THE TECHNIQUE IN THE EXPERIMENTAL CONDITIONS
Number
Liked Disliked
Relaxation 12 8
GROUP Perceived Control 9 11
Distraction 17 3
Chi square analysis of these frequencies gave a value of 7.03 which is significant (df = 2, P < 0.05). Pairwise comparisons of the groups indicated a significant difference between Distraction and the other two groups (P < 0.05). Relaxation and Perceived Control did not differ significantly. These data indicate that the Distraction condition was preferred more than the other conditions. Physiological Data. Two sets of physiological measures were analyzed. The first was heart rate in beats per minute. The second was frequency of electrodermal responses (EDRs). Both measures were sampled from three parts of the patient's record. The first was during anesthesia injection. The second was the first two minutes of cavity preparation (mostly high speed drilling), and the third period was the first two minutes of the placing and carving of the amalgam. These particular periods were sampled because our previous research had shown them to be representative of the range of patient response.
We had initially hypothesized that the Relaxation and Perceived Control groups might show decreased physiological responding from the first to second visit when compared with the Control Group, while the Distraction group would show increased response in the second session because of the mental and motor activity involved in playing the video game. Four way mixed analysis designs were employed with two within-subjects dimensions - Group x Dental Anxiety x Visit x Procedure. The analysis of heart rate gave a significant effect for Dental Anxiety (F = 9.31. df = 1/72, P < 0.05). Mean heart rate for the low anxious patients was 72.5, while the mean for the high anxious patients was 79.3. There was no relationship between heart rate and the experimental conditions. The analysis of number of EDRs per minute gave a significant Group x Visit interaction (F = 3.20, df = 1/72, P < 0.05). Again, the differences between the means (Visit 1 - Visit 2) for each group were assessed. These differences for the groups were as follows: Control, -.52; Relaxation, 1.72, Perceived Control, -.10; Distraction, -2.14. Only the differences in the Relaxation and Distraction groups were significant (P < 0.05). These results indicated less physiological arousal for the Relaxation group on the second visit and greater arousal for the Distraction group on the second visit as had been predicted. There were also significant effects for Procedure (P < 0.0001) in both physiological measures. The number of EDRs per minute showed the greatest change (decrease) from anesthesia injection to amalgam placement. The main decrease in heart rate was between cavity preparation and amalgam placement. These results are fairly consistent with previous findings. Other Analyses. The various dependent variables in this study were also analyzed in relation to the Locus of Control and Need for Social Approval measures. There was no association between our procedures and either of these personality measures. Consequently, no data have been reported in relation to these measures.
Discussion. The rating data were fairly consistent in
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STRESS REDUCTION DURING DENTAL PROCEDURES
showing significant effects for the Relaxation and Distraction conditions, as contrasted with the Control Group. The three rating measures indicated reduced discomfort during the second visit for the Relaxation and Distraction groups. It is interesting to note that there was a greater preference for the Distraction condition than for either of the other two experimental conditions. Apparently, patients like to be able to do something else during the course of a potentially unpleasant situation. Although heart rate was unrelated to the experimental conditions, the EDR response was associated with Relaxation and Distraction in the predicted directions. The results for Distraction clearly suggest that physiological arousal may accompany a perceived reduction in stress or anxiety. This finding needs further clarification in future work. It was not possible to assess sex differences adequately in this study because of the disproportionate number of male patients. Our general impression was that there were differences in the way in which males and females responded to the different techniques. This suspected difference also needs investigation in further research on stress reduction.
Conclusions. Behavioral techniques such as Relaxation and active Distraction appear to be effective in reducing anxiety and stress during operative dental procedures. The particular methods used in this research provide no basis for choosing one method over the other with respect to effectiveness. However, more patients liked Distraction than any of the other methods tested. Perceived control, as a technique by itself, does not appear to be effective in alleviating stress. Further research is needed to provide the optimal effectiveness of Relaxation and Distraction in the dental operatory.
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of Young Dental Patients, J Dent Child
37:363-374, 1970. 2. PINKHAM, J. R.; and SCHROEDER, C. S.: Dentist and Psychologist: Practical Considerations for a Team Approach to the Intensely Anxious Dental Patient, JADA 90:10221026, 1975. 3. WOLFF, B. B.: Defimition and Evaluation of Pain, Symposium on "Pain as a Problem in Compensation Medicine," American Academy of Compensation Medicine: New York, March 27, 1974. 4. LAZARUS, R. S.: Psychological Stress and the Coping Process, New York: McGrawHill, 1966. 5. AVERILL, J. R.: Personal Control over Aversive Stimuli and its Relationship to Stress, Psychol Bull 80:286-303, 1973. 6. CORAH, N. L.: Effect of Perceived Control on Stress Reduction in Pedodontic Patients, JDent Res 52:1261-1264, 1973. 7. CORAH, N. L.; BISSELL, G. D.; and ILLIG, S. J.: Effect of Perceived Control on Stress Reduction in Adult Dental Patients, J Dent Res 57:74-76, 1978. 8. OPTON, E. M., Jr.: Psychological Stress and Coping Processes in the Practice of Dentistry, Internat Dent J 19:415427, 1969. 9. WOLFF, H. G.; and GOODELL, H.: The Relation of Attitude and Suggestion to the Perception of and Reaction to Pain, Res Publ Res Assoc Nerv Ment Dis 23 :434448, 1943. 10. CARLIN, S.; WARD, D. W.; GERSHON, A.; and INGRAHAM, R.: Sound Stimulation and its Effect on Dental Sensation Threshold, Science 138:1258-1259, 1962. 11. MOROSKO, T. E.; and SIMMONS, F. F.: The Effect of Audio-analgesia on Pain Threshold and Pain Tolerance, J Dent Res 45: 1608-1617, 1966. 12. WOLPE, J.: Behavior Therapy in Complex Neurotic States, Brit J Psychiat 110:28-34, 1964. 13. GALE, E. N.; and AYER, W. A.: Treatment of Dental Phobias, JADA 78:1304-1307, 1969. 14. CORAH, N. L.: Development of a Dental Anxiety Scale, J Dent Res 48:596, 1969. 15. ROTTER, J. B.: Generalized Expectancies for Intemal Versus External Control of Reinforcement, Psychol Monogr 80:No. 1, 1966. 16. CROWNE, D. P.; and MARLOWE, D.: A New Scale of Social Desirability Independent of Psychopathology, J Consult Psychol 24: 349-354, 1960. 17. LINDQUIST, E. F.: Design and Analysis of Experiments in Psychology and Education, New York: Houghton-Mifflin, 1953, pp. 90-96. 18. EDWARDS, A. L.: Experimental Design in Psychological Research, New York: Rinehart, 1960, pp. 136-140.
We would like to acknowledge the assistance of Patricia Jankowiak, Gail Martin, Monica McDermott and Terri Schwindler in the conduct of this research. We appreciate the assistance of Dr. Jack Armitage and the staff of the School Emergency Clinic for their assistance in screening patients. REFERENCES D.W.: Managing the Anxieties 1. CHAMBERS, Downloaded from jdr.sagepub.com at FLORIDA INTERNATIONAL UNIV on May 29, 2015 For personal use only. No other uses without permission.
Behavioral methods of patient stress reduction during amalgam restorations were evaluated. Eighty adult patients were randomly assigned to one of four groups of 20 each: a control group, a relaxation group, a perceived control group, and an active distraction group. Both relaxation and distraction were found to be effective in reducing patient discomfort.
J Dent Res 58(4) :1347-1351, April 1979
Introduction. Patient stress or anxiety during dental treatment has been of major concern to dentists.1'2 In addition, anxiety appears to be an important component in the perception of pain. Wolff has maintained that affective components such as anxiety must be present for the experience of pain and that these components are largely based on learning.3 Many behaviorally-oriented suggestions for reducing stress have been given in the literature. However, there has been little or no systematic research on comparing or evaluating their effectiveness. These suggestions appear to fall into three broad categories: perceived control, distraction and relaxation. Lazarus has suggested that the individual's sense of control over a potentially aversive situation is an important element in the stress experience.4 Presumably, an individual will appraise such a situation as less threatening if he perceives himself as having some measure of control over the aversive stimulus. Most of the research in this area has been conducted in laboratory settings.
Received for publication June 9, 1978. Accepted for publication June 30, 1978. This investigation was supported in part by USPHS Research Grant DE-04494 from the National Institutes of Health, Bethesda, Maryland, 20014.
While many studies have shown that perceived control paradigms may be somewhat effective in reducing stress, the results tend to be rather mixed. It appears that, in some instances, control options can actually increase stress.5 If the results of studies conducted in a dental setting are considered, the picture is also a mixed one, with both positive and negative effects of control having been found.6'7 However, we felt that perceived control should be evaluated in the context of other methods of stress reduction. Patient distraction has often been mentioned as a means of alleviating anxiety and pain.8 Although there appears to be a strong belief in the efficacy of distraction, there is little evidence to support it. A few studies of pain tolerance have shown this technique to be successful, especially if it is combined with other variables such as suggestion or perceived control.9 10'11 There appears to be no work which has evaluated the effects of distraction on anxiety or stress responses. Our study was designed to evaluate a method of distraction in the dental context. Behavioral methods of relaxation have also been recommended as useful techniques for reducing dental stress. The basis for these techniques rests on the principle that it is impossible to be relaxed and anxious at the same time.12 Relaxation in the context of desensitization therapy has been shown to be very effective with dental phobics.13 However, this procedure is conducted outside of the feared context using the patient's imagination and requires several sessions to be successful. Successfully treated phobics are then able to undergo the required dental treatment. Our concern is with the patient who is able to approach dental treatment but finds it stressful. Therefore, we have attempted to evaluate a method of relaxing the patient during dental treatment. 1347
Downloaded from jdr.sagepub.com at FLORIDA INTERNATIONAL UNIV on May 29, 2015 For personal use only. No other uses without permission.
1348
CORAHETAL.
Our study evaluated three approaches to reducing patient anxiety and stress during dental treatment. The dental treatment selected was the Class II amalgam restoration because it is the most common restorative procedure.
Materials and methods. The subjects were 80 adult dental patients, 50 men and 30 women, who required a minimum of two Class II amalgam restorations. The patients were acquired from three different sources: the dental school admissions clinic, a preventive dentistry clinic operated for university students, and mass media reports through which patients heard about our research. A clinical examination and restorations, if necessary, were provided free of charge as an inducement for patients to participate. The patients ranged in age from 18 to 65 years with an average of 26.75 years. The design of the study was a mixedgroups-by-visit design, in which all patients received a normal restoration on the first visit with assessment of their response. On the second visit, the appropriate experimental condition was introduced for the second restoration. The patients were randomly assigned to one of four groups of 20 each on the second visit, with the restriction of maintaining approximately the same proportion of men and women in each group. The first group was a control group which received dental treatment in the same way on both visits without any technique being introduced on the second visit. The second group was the relaxation group. At the second visit, these patients wore earphones and listened to tape-recorded instructions for relaxation. The recorded voice was soft-spoken, slow and somewhat repetitive. The instructions differed from the usual technique in that patients were not told to alternately tense and relax muscle groups because the tensing of muscles might interfere with the dental procedure. Therefore, the instructions stressed the relaxation of various muscle groups with the exception of the jaw muscles. The presentation was begun three to four minutes before the dentist administered anesthesia and continued until the dental procedure was completed.
J Deti t Res April 1 9 79
The third group involved the perceived control condition. The patient was given a button switch to hold in his hand during the dental procedure. He was told that it would permit him to communicate with the dentist or have the dentist stop for a moment if the patient felt the need for a rest. The button turned on a red light and sounded a buzzer when activated. A demonstration was provided prior to the beginning of the dental procedure. The distraction group was involved in an active task. The patient played a video ping pong game "against the house." The television monitor was mounted near the ceiling for comfortable viewing bv the reclining patient. A small box was clamped to the arm of the dental chair and contained the "joy stick" control for the game and a small reset button to begin a new game. Scoring for the patient and the "house" was indicated on opposite sides of the video screen. The patient was instructed that he could play the game throughout the entire dental procedure. The patient signed a consent form at the beginning of his first visit. He then filled out the Corah Dental Anxiety Scale, the Rotter Locus of Control Scale and the Need for Social Approval Scale.14,15,16 Silver-silver chloride electrodes were taped over cornpads filled with electrode jelly and attached to the palmar surface of the distal phalanges of the first and third fingers of the non-preferred hand. These electrodes were used for recording the electrodermal response (EDR). A digital strain gauge was placed on the second finger for recording heart rate (HR). The patient was then taken to the dental operatory, seated, and the electrodes and strain gauge were plugged into their connectors. Physiological recording and video monitoring took place in a room adjacent to the dental operatory. EDRs and HR were recorded throughout the dental procedure. At the end of the first session and after the patient had left the operatory, he was asked to rate his level of discomfort during the procedure on a seven-point scale ranging from Calm, Relaxed to Tense-Upset. The dentist also rated the patient on the same scale. In general, an attempt was made to have the two dental appointments one week apart. In 15 cases, the interval was two weeks; in three cases, the interval was one
Downloaded from jdr.sagepub.com at FLORIDA INTERNATIONAL UNIV on May 29, 2015 For personal use only. No other uses without permission.
Vol 58 No 4
STRESS REDUCTION DURING DENTAL PROCEDURES
day. The appropriate condition was then introduced when the patient returned for the second visit. At the end of the second dental procedure, the patient again rated himself on the seven-point scale of discomfort (as did the dentist) and was asked a series of questions relating to his attitudes and feelings about the procedures. The patient was then debriefed and had the entire study explained, and all questions were answered. In the event that further dental work was required, appropriate referrals were made. Analyses of variance were conducted on all measures obtained from the first visit, including age, for the four groups. All F ratios were less than 1.00, indicating that the four groups were comparable on these measures.
Results. Rating Data. All analyses were made in terms of Group x Dental Anxiety x Visit. All groups were divided into high and low dental anxiety on the basis of a median split. The median score was nine. Where more than one person achieved this score in a given group, assignment to high or low dental anxiety groups was achieved by ran-
dom assignment. All analyses of patient discomfort were mixed analyses of variance with one within-subject dimension (visit). The implicit hypothesis for these data was that the change in ratings from visit one to visit two would differ in the various groups. The analysis of patient self-ratings of discomfort yielded four significant effects. There was a main effect for Dental Anxiety (F = 15.01, df = 1/72, P < 0.005), which indicated that high anxiety patients gave higher discomfort ratings (mean = 3.52) than low anxiety patients (mean = 2.50). There was also a significant main effect for Visit (F = 7.50, df = 1/72, P < 0.05), which indicated higher discomfort ratings for the first visit (mean = 3.20) than for the second visit (mean= 2.82). There was a significant Group x Visit interaction (F = 3.23, df = 3/72, P < 0.05), which is of more interest in the present study. The difference between the means (Visit 1 - Visit 2) for each group was tested by the "critical difference" method.17 The differences between the means for each
1349
group were as follows: Control, 0.0; Relaxation, .80; Perceived Control, -.10; Distraction, .80. Only the differences in the Relaxation and Distraction groups were significant (P < 0.05). These results indicate that the patients in these two groups rated themselves as experiencing less discomfort during the second visit than during the first visit. There was also a significant triple interaction among Group x Dental Anxiety x Visit (F = 5.28, df = 3/72, P < 0.005), which was similar to the Group x Visit interaction. With the smaller cell size, the difference between visit one and visit two was significant (P < 0.05) only for the high anxiety patients in the Relaxation and Distraction groups. These results suggest that, as far as self ratings are concerned, the relaxation and distraction conditions were especially effective with the high dentally anxious patients. The dentist's ratings of patient discomfort were somewhat similar to those of the patients themselves. There were two signifia main effect for Visit (F = cant effects 15.72, df = 1/72, P < 0.001), and the Group x Visit interaction (F = 3.48, df = 3/72, P < 0.05). The differences between the means (Visit 1 - Visit 2) for the different groups were: Control, -.05; Relaxation, 1.35; Perceived Control, .50; Distraction, .65. Again, the ratings of patient discomfort made by the dentist were significantly lower on the second visit for only the Relaxation and Distraction groups (P < 0.05). A third rating included for analysis was based on a question on the final rating sheet. Patients were asked which visit they liked better - the first or second - and why. Their answers were keyed 1, 2, or 3 on the following criteria. They were given a 1 if they said they preferred the first session, a 2 if they said they were the same or that there was no difference, and a 3 if they clearly preferred the second session. These scores were then subjected to a Group x Dental Anxiety analysis of variance. A significant effect was obtained for Groups (F = 2.79, df = 1/72, P < 0.05). The means obtained for the groups were: Control, 2.00; Relaxation, 2.60; Perceived Control, 2.35; Distraction, 2.70. A Duncan's Multiple Range Test was applied to these means.18 The means for the Relaxation and Distraction groups were significantly different (P < 0.05) from the Control group, indi-
Downloaded from jdr.sagepub.com at FLORIDA INTERNATIONAL UNIV on May 29, 2015 For personal use only. No other uses without permission.
1350
J Deti t Res April 1 9 79
CORAHETAL.
cating greater preference of those two groups for the experimental treatment visit. No other comparisons were significant. Patients were asked a number of openended questions at the conclusion of the second visit. Two of them were directly related to what they thought of the particular technique that had been introduced into the second visit. Three project staff members independently categorized these answers from the patients in the three experimental groups as to whether the patient liked the procedure or disliked the procedure. Disagreement among the raters as to classification ranged from one to two cases. In these few instances, the category agreed upon by two of the three raters was used. The frequencies are shown in the Table. TABLE FREQUENCY OF PATIENT PREFERENCES FOR THE TECHNIQUE IN THE EXPERIMENTAL CONDITIONS
Number
Liked Disliked
Relaxation 12 8
GROUP Perceived Control 9 11
Distraction 17 3
Chi square analysis of these frequencies gave a value of 7.03 which is significant (df = 2, P < 0.05). Pairwise comparisons of the groups indicated a significant difference between Distraction and the other two groups (P < 0.05). Relaxation and Perceived Control did not differ significantly. These data indicate that the Distraction condition was preferred more than the other conditions. Physiological Data. Two sets of physiological measures were analyzed. The first was heart rate in beats per minute. The second was frequency of electrodermal responses (EDRs). Both measures were sampled from three parts of the patient's record. The first was during anesthesia injection. The second was the first two minutes of cavity preparation (mostly high speed drilling), and the third period was the first two minutes of the placing and carving of the amalgam. These particular periods were sampled because our previous research had shown them to be representative of the range of patient response.
We had initially hypothesized that the Relaxation and Perceived Control groups might show decreased physiological responding from the first to second visit when compared with the Control Group, while the Distraction group would show increased response in the second session because of the mental and motor activity involved in playing the video game. Four way mixed analysis designs were employed with two within-subjects dimensions - Group x Dental Anxiety x Visit x Procedure. The analysis of heart rate gave a significant effect for Dental Anxiety (F = 9.31. df = 1/72, P < 0.05). Mean heart rate for the low anxious patients was 72.5, while the mean for the high anxious patients was 79.3. There was no relationship between heart rate and the experimental conditions. The analysis of number of EDRs per minute gave a significant Group x Visit interaction (F = 3.20, df = 1/72, P < 0.05). Again, the differences between the means (Visit 1 - Visit 2) for each group were assessed. These differences for the groups were as follows: Control, -.52; Relaxation, 1.72, Perceived Control, -.10; Distraction, -2.14. Only the differences in the Relaxation and Distraction groups were significant (P < 0.05). These results indicated less physiological arousal for the Relaxation group on the second visit and greater arousal for the Distraction group on the second visit as had been predicted. There were also significant effects for Procedure (P < 0.0001) in both physiological measures. The number of EDRs per minute showed the greatest change (decrease) from anesthesia injection to amalgam placement. The main decrease in heart rate was between cavity preparation and amalgam placement. These results are fairly consistent with previous findings. Other Analyses. The various dependent variables in this study were also analyzed in relation to the Locus of Control and Need for Social Approval measures. There was no association between our procedures and either of these personality measures. Consequently, no data have been reported in relation to these measures.
Discussion. The rating data were fairly consistent in
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Vol 58 No 4
STRESS REDUCTION DURING DENTAL PROCEDURES
showing significant effects for the Relaxation and Distraction conditions, as contrasted with the Control Group. The three rating measures indicated reduced discomfort during the second visit for the Relaxation and Distraction groups. It is interesting to note that there was a greater preference for the Distraction condition than for either of the other two experimental conditions. Apparently, patients like to be able to do something else during the course of a potentially unpleasant situation. Although heart rate was unrelated to the experimental conditions, the EDR response was associated with Relaxation and Distraction in the predicted directions. The results for Distraction clearly suggest that physiological arousal may accompany a perceived reduction in stress or anxiety. This finding needs further clarification in future work. It was not possible to assess sex differences adequately in this study because of the disproportionate number of male patients. Our general impression was that there were differences in the way in which males and females responded to the different techniques. This suspected difference also needs investigation in further research on stress reduction.
Conclusions. Behavioral techniques such as Relaxation and active Distraction appear to be effective in reducing anxiety and stress during operative dental procedures. The particular methods used in this research provide no basis for choosing one method over the other with respect to effectiveness. However, more patients liked Distraction than any of the other methods tested. Perceived control, as a technique by itself, does not appear to be effective in alleviating stress. Further research is needed to provide the optimal effectiveness of Relaxation and Distraction in the dental operatory.
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We would like to acknowledge the assistance of Patricia Jankowiak, Gail Martin, Monica McDermott and Terri Schwindler in the conduct of this research. We appreciate the assistance of Dr. Jack Armitage and the staff of the School Emergency Clinic for their assistance in screening patients. REFERENCES D.W.: Managing the Anxieties 1. CHAMBERS, Downloaded from jdr.sagepub.com at FLORIDA INTERNATIONAL UNIV on May 29, 2015 For personal use only. No other uses without permission.
