Computerized dental injection fear treatment: a randomized clinical trial.

One in four adults reports a clinically significant fear of dental injections, leading many to avoid dental care. While systematic desensitization is the most common therapeutic method for treating specific phobias such as fear of dental injections, lack of access to trained therapists, as well as dentists' lack of training and time in providing such a therapy, means that most fearful individuals are not able to receive the therapy needed to be able to receive necessary dental treatment. Computer Assisted Relaxation Learning (CARL) is a self-paced computerized treatment based on systematic desensitization for dental injection fear. This multicenter, block-randomized, dentist-blind, parallel-group study conducted in 8 sites in the United States compared CARL with an informational pamphlet in reducing fear of dental injections. Participants completing CARL reported significantly greater reduction in self-reported general and injection-specific dental anxiety measures compared with control individuals (p < .001). Twice as many CARL participants (35.3%) as controls (17.6%) opted to receive a dental injection after the intervention, although this was not statistically significant. CARL, therefore, led to significant changes in self-reported fear in study participants, but no significant differences in the proportion of participants having a dental injection.

Recruiting phobic research subjects: effectiveness and cost.

Efficiently enrolling subjects is one of the most important and difficult aspects of a clinical trial. This prospective study evaluated strategies used in the recruitment of 144 dental injection phobics for a clinical trial evaluating the effectiveness of combining alprazolam with exposure therapy. Three types of recruitment strategies were evaluated: paid advertising, free publicity, and professional referral. Sixty-three percent of subjects were enrolled using paid advertising (the majority of them from bus advertisements [27.0%], posters on the University of Washington campus [20.1%], and newspaper advertisements [13.2%]). Free publicity (eg, television coverage, word of mouth) yielded 18.8% of enrolled subjects and professionaL referrals 14.6% of subjects. The average cost (1996 dollars) of enrolling 1 subject was $79. Bus and poster advertising attracted more initial contacts and yielded the greatest enrollment.

Reliability of individual differences in initial sensitivity and acute tolerance to nitrous oxide hypothermia.

On average, the hypothermia exhibited by rats receiving 60% nitrous oxide (N2O) eventually abates despite the continued inhalation of the drug (i.e., acute tolerance develops). However, large individual differences occur in both the magnitude of hypothermia achieved and the degree of acute tolerance that develops. To determine whether the degree of temperature loss and subsequent recovery during N2O administration are reliable characteristics of an individual, we measured intraperitoneal temperature via telemetry in 77 Long-Evans rats that each received 60% N2O for 5 h during two sessions separated by 14 days. Good intersession reliability (Pearson's r) was observed for simple change and adjusted change scores for both initial N2O temperature sensitivity (.61 < or = r < or = .62), and acute tolerance development (.46 < or = r < or = .52). In a separate experiment, three groups of rats were selected based on their individual body temperature patterns during an initial N2O administration: (1) insensitive to N2O hypothermia (n = 8); (2) marked hypothermia followed by acute tolerance development (n = 6); and (3) marked hypothermia followed by little acute tolerance development (n = 6). When retested 10 days later, each group exhibited a body temperature profile similar to that observed during the initial N2O exposure. Thus, the temperature profile observed during a rat's initial exposure to 60% N2O reflects a reproducible response for that animal.

Pharmacokinetics and clinical effects of sublingual triazolam in pediatric dental patients.

The purpose of this investigation was to describe the pharmacokinetics of sublingual triazolam in children. Nine healthy children (64-98 months old) received 0.25 or 0.375 mg of sublingual triazolam before dental treatment. Plasma triazolam concentrations were measured by gas chromatography/mass spectrometry and analyzed by noncompartmental methods. The peak concentration was 4.9 +/- 2.0 ng/mL (mean +/- SD), time to peak was 75 +/- 32 minutes, the elimination half-life was 91 +/- 32 minutes, and apparent clearance was 17.6 +/- 8.8 mL x kg(-1) x min(-1). Children were tested for gait ataxia, amnesia, and diplopia during a screening session and again after triazolam. Ninety minutes after drug administration, seven of nine children demonstrated ataxia, and three of nine demonstrated amnesia. Peak triazolam concentrations were similar in children with or without ataxia, but they were significantly higher in children with amnesia compared with those without amnesia. Six children demonstrated diplopia 30 and 120 minutes after triazolam; however, peak triazolam concentrations were similar in both groups. Sublingual administration was an acceptable alternative route of triazolam delivery in children.

Psychiatric diagnoses among self-referred dental injection phobics.

In order to determine the psychiatric characteristics of people with dental injection phobia. 118 dental injection phobics were systematically assessed using a structured clinical interview and a written questionnaire. Fifty-four percent of subjects had a current Axis I diagnosis other than dental injection phobia, mainly anxiety, mood or adjustment disorder, and 68.6% of subjects had an additional lifetime Axis I diagnosis. Subjects with additional current Axis I diagnoses reported higher dental anxiety, greater severity of injection fear cognitions, and poorer relationships with dental professionals, than did subjects without any or with past Axis I diagnoses. Further investigation is needed to explore the treatment possibilities for patients with and without additional current diagnoses.

Children's acceptance of xylitol-based foods.

UNLABELLED: Daily consumption of xylitol (5-10 g/day) added to chewing gum and confectionary foods has been previously shown to prevent dental caries in children. METHODS: Snack foods containing xylitol were developed and tested for acceptability in a convenience sample of 31 children ages 3 to 6 years. In order to mimic an after-meal snack, all children were tested during mid-morning, approximately 1 h after eating. Preference testing was based on the methodology of Birch et al. (J Nutr Educ, 1979; 11: 77-80). In the first phase, each child was presented with a tray of six xylitol-based foods (popsicles, pudding, gum drops, gelatin dessert, cookies, popcorn) and asked to taste each item in any desired order. Immediately after tasting a food, the child was asked to place it in front of one of three cartoon faces (smile, frown or neutral) representing the child's response to the taste of that particular food. In the second phase, the child was asked to rank order the foods in each face category (smile, frown or neutral). Ranks within categories were then combined to obtain a rank ordering for all of the foods. RESULTS: Non-parametric data analysis indicated significant differences in ranking between the foods when they were compared to each other (Friedman ANOVA by ranks, P<0.01). Pudding was significantly less preferred than the other foods (sign tests, P<0.04). At least 84% of the children found five of the six foods very good or satisfactory, when considered individually. CONCLUSIONS: These results suggest that snack foods developed with xylitol are generally well accepted by children.

Effectiveness of local anesthesia in pediatric dental practice.

BACKGROUND: Pain control in dental treatment for children is very important. The purpose of this study is to describe the characteristics of local anesthetic use by pediatric dentists and to examine factors related to its effectiveness in children. METHODS: The authors observed 361 patients in 17 pediatric dental practices in Washington state while each child received restorative or surgical dental treatment. The authors recorded data concerning local anesthetic use and effectiveness. The children's mean age was 87 months, and 181 (50.1 percent) of the patients were girls. A pediatric dentist observer rated each child's anxiety before the initial injection of local anesthetic and the effectiveness of pain control during restorative treatment. The observing dentist asked the treating dentist about the effectiveness of pain control after completion of treatment. RESULTS: Forty-two of 361 children (11.6 percent) were observed to experience ineffective pain control. Fourteen of 17 dentists (82.4 percent) were observed to have at least one patient in whom pain control was ineffective. Lidocaine (2 percent with 1:100,000 epinephrine) was used by 15 of 17 dentists (88.2 percent) and in 312 of 361 cases (86.4 percent). The average amount of agent was one cartridge (36 milligrams of lidocaine). Children who were anxious, who had symptoms before treatment, and who underwent more invasive operative and endodontic procedures were more likely to experience ineffective pain control. CONCLUSIONS: The data suggest that painful treatment is relatively frequent even in specialized pediatric practice. Variability in general practice is likely to be greater. CLINICAL IMPLICATIONS: The incidence of ineffective pain control may be less if clinicians use methods to reduce anxiety and perioperative infection and symptoms.

A randomized clinical trial of triazolam in 3- to 5-year-olds.

Triazolam has shown promise as a sedative agent for use in pediatric dentistry. However, the efficacy of triazolam has not been previously examined in a placebo-controlled study. The present clinical trial used a two-group, randomized, double-blind study design to compare the efficacy of oral triazolam with that of a placebo. The primary hypothesis tested was that triazolam would reduce negative behaviors of pediatric dental patients compared with a placebo. A secondary hypothesis was that triazolam would increase the efficiency of dental treatment by reducing the need for time-consuming behavior management by the pediatric dentist. The subjects were 54 3- to 5-year-old children, randomly assigned to the drug and placebo groups. The active drug, 0.03 mg/kg triazolam (Halcion), or lactose placebo was given orally 30 min before dental treatment. Behavior management techniques commonly used in pediatric dentistry were used during dental treatment. A single pediatric dentist provided all of the dental treatment. The procedure included an inferior block anesthesia and careful attention to anesthesia effectiveness. All sessions were video-taped and the tapes coded for child and dentist behaviors by an independent observer. There were no statistically significant differences between the groups with respect to completion of dental treatment. There were no significant differences found in either the total time or the percent of time that the subjects exhibited disruptive movements, verbal or non-verbal distress. The total use of time in the dental chair was slightly higher in the placebo than in the drug group due to more time spent preparing the child. Contrary to preliminary reports in the literature, this investigation found little or no improvement in child behavior when triazolam was used as a sedative compared with a placebo. However, triazolam did shorten the length of dental treatment, primarily by reducing dentist time in preparing the child for the dental procedure (e.g., establishing rapport and shaping behavior).

Side effects of triazolam in children.

PURPOSE: This study examined the incidence of side effects occurring with three doses of orally administered triazolam in children undergoing restorative dental procedures. METHODS: Thirty children, aged 39-81 months, participated in the study. The children were pretested for gait ataxia, amnesia, visual acuity, stereoscopic depth perception, and diplopia during a screening session. In a subsequent appointment, children received one of three triazolam dosages (0.005, 0.015, and 0.030 mg/kg) prior to dental treatment. Dosage assignment was random and double blind. Each child received a single triazolam dosage. Tests for gait ataxia, amnesia, and visual disturbances were repeated following drug administration. RESULTS: The proportion of children experiencing ataxia, amnesia, and diplopia increased with increasing triazolam dosages. The 0.030-mg/kg triazolam dosage impaired visual acuity and stereoscopic depth perception. CONCLUSION: Triazolam produces ataxia, amnesia, and diplopia in a dose-dependent manner in children.

Dental fear among university employees: implications for dental education.

We surveyed 350 University of Washington permanent employees chosen randomly from among both faculty and staff. The aim was to determine the extent and nature of dental anxiety in the university population potentially available for teaching clinics. In addition, the relationship of fears to self-reported dental health, utilization of dental care, and other general and mental health issues was examined. Dental anxiety was prevalent in this population; 13 percent of subjects reported high dental fear. In contrast to respondents with lower dental fear, subjects with clinically significant fear reported poorer perceived dental health, a longer interval since their last dental appointment, a higher frequency of past fear behaviors, more physical symptoms during last dental injection, and higher percentage of symptoms of anxiety and depression. Dental anxiety was not associated with poorer perceived general health or a longer interval since the last dental injection. University employees are a rich source of potential teaching patients for achieving curricular requirements for managing anxious patients. Student clinicians need guidance to be able to recognize fearful patients; they also need instruction about psychiatric conditions like anxiety and depression in order to be able to better manage and prevent dropouts in their patient roster.

CARL: a LabVIEW 3 computer program for conducting exposure therapy for the treatment of dental injection fear.

This paper describes CARL (Computer Assisted Relaxation Learning), a computerized, exposure-based therapy program for the treatment of dental injection fear. The CARL program operates primarily in two different modes; in vitro, which presents a video-taped exposure hierarchy, and in vivo, which presents scripts for a dentist or hygienist to use while working with a subject. Two additional modes are used to train subjects to use the program and to administer behavioral assessment tests. The program contains five different modules, which function to register a subject, train subjects to use physical and cognitive relaxation techniques, deliver an exposure hierarchy, question subjects about the helpfulness of each of the therapy components, and test for memory effects of anxiolytic medication. Nine subjects have completed the CARL therapy program and 1-yr follow-up as participants in a placebo-controlled clinical trial examining the effects of alprazolam on exposure therapy for dental injection phobia. All nine subjects were able to receive two dental injections, and all reduced their general fear of dental injections. Initial results therefore indicate that the CARL program successfully reduces dental injection fear.

Acute tolerance and reversal of the motor control effects of midazolam.

The purpose of this study was to determine whether acute tolerance develops to the motor control effects of the short-acting benzodiazepine, midazolam. Using a bolus and constant infusion scheme, 40 healthy adults received a 70-min intravenous infusion of either saline (n = 20) or 6.1 (SE = 0.2) mg midazolam (n = 20). Following the 70-min infusion period, half of the subjects in each group (n = 10) received a 25-min intravenous infusion of flumazenil (benzodiazepine antagonist); the remainder of the subjects (n = 10/group) received a 25-min infusion of saline. Drug administration during both infusion periods was double blind. Prior to the infusions, subjects were trained in a motor control assessment battery. Throughout both infusions, repeated motor control testing and blood sampling were performed. The initial (10 min) midazolam plasma concentration was 52.0 (SE = 2.2) ng/ml. Plasma midazolam concentration rose gradually to 60.7 (SE = 2.1) ng/ml at the end of the infusion (70 min). Midazolam initially impaired performance on the motor control tasks. However, performance improved in subjects receiving midazolam despite the gradual increase in midazolam concentrations. This suggests that the recovery of motor task performance may be attributable to the development of acute tolerance rather than to waning drug concentrations. Flumazenil immediately reversed midazolam's effects on the visual tracking task. However, there was little evidence for precipitation of muscle force rebound, which has been hypothesized to result from the same underlying mechanism that is responsible for acute tolerance development.

Dental fear among university students: implications for pharmacological research.

University students are often subjects in randomized clinical trials involving anxiolytic and analgesic medications used during clinical dental and medical procedures. The purpose of this study was to describe a typical university student population available for research by using data from a mail survey. Subjects were 350 students chosen randomly from all enrolled, full-time, traditional students on the main campus at the University of Washington in Seattle, WA. The aim was to determine the extent and nature of dental anxiety in this population. In addition, the relationships between subject willingness to receive dental injections and general and mental health and medical avoidance and medical fears were examined. The Dental Anxiety Scale (DAS) was used to measure dental anxiety. Dental anxiety was prevalent in this population; 19% of students reported high rates of dental fear. Thirteen percent of students had never had a dental injection. Students with no experience with dental injections were more reluctant than those with experience to receive an injection if one were needed. DAS scores were correlated with injection reluctance. Students who were reluctant to go ahead with a dental injection also reported poorer general and mental health than those who were less reluctant. These students also reported higher medical avoidance and medical anxiety scores. University students provide a rich source of potential subjects for clinical research. The student population, like the community at large, contains people with high levels of dental and medical fear.

Plasma levels of 2% lidocaine with 1:100,000 epinephrine with young children undergoing dental procedures.

Lidocaine levels were determined for 12 children, aged 55 to 150 mo, who received routine dental treatment, including multiple intraoral injections of 2% lidocaine (2.6 to 6.4 mg/kg) with 1:100,000 epinephrine. Peak plasma concentrations of lidocaine ranged from 0.7 to 3.8 mug/ml at 5 to 15 min postinjection. Generally accepted threshold concentrations for the onset of central nervous system toxicity are 5 to 10 mug/ml. In this study, no child approached these levels when given local anesthesia for dental procedures.

Amnestic and anxiolytic effects of alprazolam in oral surgery patients.

PURPOSE: This study was designed to identify a dose of alprazolam that would reduce anxiety associated with oral surgery without causing accompanying memory impairment. PATIENTS AND METHODS: Thirty-six subjects in experiment 1 and 48 subjects in experiment 2 were pretested on a computerized memory battery to establish baseline performance. Subjects were then randomly assigned to receive placebo, 0.25 mg, or 0.75 mg oral alprazolam (experiment 1) or placebo, 0.25 mg, 0.50 mg, or 0.75 mg oral alprazolam (experiment 2). Forty-five minutes after the double-blind administration of alprazolam, subjects were given a second memory battery. The memory batteries tested story recall and recognition and word recall and recognition. Subjects in experiment 2 subsequently underwent oral surgery for the removal of one to four molars. The subjects completed anxiety questionnaires both before and after surgery. RESULTS: The 0.75-mg and 0.50-mg doses, but not the 0.25-mg dose, impaired word recall. The 0.75-mg dose also impaired story recall and recognition. The proportion of subjects reporting moderate to high anxiety during oral surgery decreased with increasing doses of alprazolam. Multiple regression indicated that the 0.75-mg alprazolam dose significantly decreased anxiety during oral surgery. The 0.25-mg and 0.50-mg doses also tended to reduce anxiety, but beta values for these doses did not reach significance. CONCLUSIONS: These findings indicate that alprazolam produces memory impairment at the dosages necessary to produce clinically significant anxiolysis during oral surgery.

Four dimensions of fear of dental injections.

In 1995, students and staff at the University of Washington were surveyed regarding avoidance of dental care and fear of dental injections. More than 25 percent of adults surveyed expressed at least one clinically significant fear of injections. Almost one in 20 respondents indicated avoiding, cancelling or not appearing for dental appointments because of fear of dental injections. Fear of dental injections consists of four dimensions. General fear of dental injections including pain of injection and of bodily injury from injection are the two most common dimensions of dental injection fear. Many people also express fears of acquired disease. Fear related to local anesthetic (such as side effects, inadequate anesthesia) is less frequent. Some respondents have fears that must be categorized using more than one of these dimensions. Understanding the nature of a patient's fear of injection may suggest strategies to address his or her concerns.

Pharmacokinetics of oral triazolam in children.

The purpose of this study was to determine the pharmacokinetic behavior of triazolam in children. Nine healthy children, aged 6 to 9 years, received oral triazolam (0.025 mg/kg suspended in Kool-Aid, Kraft General Foods, Chicago, IL) before dental treatment. Plasma triazolam concentrations were measured by gas chromatography/mass spectrophotometry at approximately 5, 15, 30, 45, 60, 90, 120, 180, and 240 minutes. A one-compartment model with first-order absorption and varying parameters was used, and estimated concentration curves were obtained for each subject. The observed peak plasma concentration was 8.5 +/- 3.0 ng/mL (mean +/- SD). The observed time to peak plasma concentration was 74 +/- 25 minutes. Elimination half-life was 213 +/- 144 minutes. Substantial recovery from signs and symptoms of clinical sedation required 180 to 240 minutes. The long duration of effect and relatively slow elimination should be noted by clinicians concerned with patient safety.

Acceptance of minerals and other compounds by calcium-deprived rats: 24-h tests.

We measured 24-h spontaneous intake of four to eight concentrations of 31 different solutions by groups of rats fed control or low-calcium diets. Relative to controls, those fed low-calcium diet had increased acceptance of one or more concentrations of sodium chloride, sodium acetate, and sodium bicarbonate, but not sodium gluconate. Differences in palatability between these sodium salts were unimportant because the rats fed low-calcium diet consumed more sodium chloride even if this was made less acceptable by adulteration with citric acid. The possibility that calcium-deprived rats have an enhanced general cation or mineral appetite was supported by findings of increased acceptance of one or more concentrations of nine of ten chloride minerals tested (aluminum chloride, ammonium chloride, ferric chloride, ferrous chloride, magnesium chloride, sodium chloride, potassium chloride, strontium chloride, zinc chloride). However, there were no differences in acceptance of any concentration of cesium chloride, magnesium sulfate, or lead acetate. Moreover, calcium-deprived rats drank more hydrochloric acid and malic acid than did controls. Thus the effect of calcium deficiency on intake was not confined to minerals. Acidity or bitterness did not appear important because there was no difference between the groups in intake of sulfuric acid, citric acid, or quinine hydrochloride. Consistent with the exacerbating effects of phosphates on calcium deprivation, deprived rats had decreased intakes of phosphates (sodium phosphate, potassium phosphate). However, they also had decreased intakes of sucrose and saccharin. It is clear that calcium deprivation does not induce a general increase in acceptance of all taste solutions, but there appears to be no simple explanation for what these animals consume.

Immediate acceptance of minerals and HCl by calcium-deprived rats: brief exposure tests.

We conducted two experiments to test the hypothesis that calcium consumption by calcium-deprived rats is unlearned and guided by oral cues. In experiment 1, we gave 23.5-h water-deprived control and calcium-deprived rats 30-min tests with water and various taste solutions. Relative to controls, calcium-deprived rats licked significantly less water and more 300 mM Ca.lactate in the first minute, more 50 mM HCl and 125 mM HCl in the first 10 min, and more 75 mM CaCl2, 150 mM CaCl2, and 300 mM CaCl2 by the end of the 30-min session. There was no difference between the groups at any time in lick rates for sodium solutions, quinine hydrochloride, sucrose octaacetate, or saccharin. In experiment 2, we gave 23-h water-deprived control, calcium-deprived, and sodium-deprived rats 10-min tests. During the first minute, calcium-deprived rats licked more than did control and sodium-deprived rats for 100 mM CaCl2, 100 mM FeCl2, and 20 mM Pb.acetate. Sodium-deprived rats licked more than did control and calcium-deprived rats for 600 mM NaCl and less than did controls for 200 mM L-histidine. At the end of the 10-min session, sodium-deprived rats had higher lick rates for 100 mM FeCl2 than did control rats. There were no differences between the groups in lick rates for 1 mM quinine hydrochloride, 100 mM SrCl2, or 20 mM citric acid. The results suggest that calcium-deprived rats use innate oral factors to guide consumption of calcium and other solutions.

Latent learning about calcium and sodium.

We used the latent-learning paradigm to examine whether replete rats can recognize sodium and calcium and whether they use that knowledge to guide consumption when subsequently mineral deprived. Rats fed a nutritionally complete diet received four pairs of 17-h training trials. During one trial of each pair, the rats drank grape- or cherry-flavored water; during the other, they drank the other flavor mixed with 100 mM CaCl2 (experiment 1), 750 mM NaCl (experiment 2), or 584 mM (20% wt/vol) sucrose (experiment 3). The rats were then fed nutritionally complete, calcium-deficient, or sodium-deficient diet for 3 wk and were given a two-bottle preference test between the two flavors. Relative to rats fed complete diet, calcium-deprived rats had elevated preferences for calcium- and sodium-paired flavors but not sucrose-paired flavors. Sodium-deprived rats had elevated preferences only for sodium-paired flavors. These results provide evidence for the existence of innate calcium and sodium appetites in calcium-deprived rats. They indicate that these distinct appetites are centrally generated behaviors and are not simply due to peripheral alterations in taste perception.