Giant calcifying epithelial odontogenic tumor after I-125 seed implantation: A case report.

Calcifying Epithelial Odontogenic Tumor (CEOT), also known as Pindborg tumor, is a rare odontogenic benign tumor. It was first reported by Thoma and Goldman in 1946 and defined as an independent tumor by Pindborg in 1957. Herein, we reported a CEOT case involving most of the mandible after I-125 implantation in a 53-year-old man. We cooperated with governmental and hospital departments to resect the tumors, reconstruct the mandible with a fibular flap graft, and properly dispose of the radioactive particles.

Efficacy of continuous intravenous remimazolam versus midazolam in the extraction of impacted wisdom teeth: protocol of a randomised controlled trial.

INTRODUCTION: Benzodiazepines such as midazolam are widely used to moderately sedate patients during impacted wisdom tooth extraction to reduce anxiety in outpatient surgery. This present protocol was designed to determine whether continuous intravenous remimazolam, a new ultrashort-acting benzodiazepine, produces superior postoperative recovery quality to that of midazolam in patients undergoing extraction of impacted wisdom teeth. METHODS AND ANALYSIS: This study is a multicentre randomised controlled trial conducted at Peking Union Medical College Hospital, Beijing Anzhen Hospital and Beijing Shijitan Hospital in China. Approximately 150 participants undergoing extraction of impacted mandibular wisdom teeth will be randomly allocated to two groups (remimazolam and midazolam). The participants will be administered standard interventions to ensure they achieve a sedation level of III on the Ramsay sedation scale during the treatment. Preoperative and anaesthesia management and surgical techniques will be standardised for all participants. The primary outcome is recovery time for complete alertness and the secondary outcomes are anterograde amnesia during and after surgery, and interruption during operation for poor compliance or safety concerns. ETHICS AND DISSEMINATION: This study has been approved by the Ethics Review Committee of Peking Union Medical College Hospital (approval number: ZS-3142), Beijing Anzhen Hospital (approval number: KS2022082) and Beijing Shijitan Hospital (approval number: 2023-4). TRIAL REGISTRATION NUMBER: NCT05350085.

Medical Emergencies in Dental Clinics: A Survey of 2013 Dentists in China.

Objective To investigate the feature and frequency of medical emergencies in dental clinics in China and the associated factors for Chinese dentists experiencing medical emergencies.Methods A survey study was conducted among 2408 dentists who attended continuing educational courses held by Society of Sedation and Analgesia of Chinese Stomatological Association in 18 cities from December 2015 to December 2018. Demographic information of the dentists and the characteristics of medical emergencies they encountered were collected and analyzed. The associated demographic features for dentist experiencing medical emergencies were analyzed by logistic regression model.Results A total of 2013 dentists provided valid responses and reported 2923 events of medical emergencies in dental clinics. Among them, 85.0% reported that they had encountered medical emergencies, and 35.5% had encountered at least twice. Syncope (35.9%) and hypoglycemia (30.3%) were the most common reported medical emergencies. Medical emergencies were most likely to occur during local anesthesia (49.9%), out-patient oral surgery (25.9%), and root canal treatment (11.3%). There were 6 patients (0.2%) died in emergencies. 84.0% dentists reported that they had never received training courses about medical emergency management in dentistry other than Basic Life Support. Longer practicing time (10-15 years) (OR=0.59, 95% CI: 0.41-0.85, P=0.004), working in private dental facilities (OR=1.69, 95% CI: 1.20-2.38, P=0.003) were associated with an increased risk of experiencing medical emergencies.Conclusion More efforts are needed in prevention, early identification, and timely management of medical emergencies in dental clinics in order to prevent fatal outcomes. The results of this survey are useful information for re-designing emergency training courses for Chinese dentists.

[Effectiveness and Safety of Oral Midazolam Combined Nitrous Oxide Sedation in Treating Children with Dental Fear].

Objective To evaluate the safety and effectiveness of oral midazolam sedation combined nitrous oxide sedation for reducing dental fear in children.Methods Totally 77 children with a Frankl's Behavior Rating Scale score of 1 were included in this study,among whom 41 received a total of 78 person-times of oral midazolam sedation (0.50-0.75 mg·kg -1) (midazolam group) and 36 children were treated with the combination of 0.4 mg/kg oral midazolam with 30%-40% nitrous oxide (totally 73 person-times)(combination group). At each visit,heart rate,arterial oxygen saturation,and treatments were recorded. The behaviors of children during the treatment were assessed by Frankl's Behavior Rating Scale,the completion of treatment was assessed by Houpt Scale,and the sedation status was assessed by Ramsay Scale. Telephone follow-up was performed to record the side effects 24 hours after treatment. Results The vital signs were stable among all the 77 subjects,with a Ramsay score of 2 or 3. In the midazolam group, the behaviors were cooperative in 52 person-times (66.7%) and not cooperative in 26 person-times (33.3%);the planned treatments were completed in 62 person-times (79.5%) and partially completed in 16 person-times(20.5%). In the combination group,the behaviors were cooperative in 56 person-times (76.7%) and not cooperative in 17 person-times (23.3%);64 person-times (87.7%) completed the planned treatments and 9 person-times (12.3%) partially completed the treatments. The success rates of sedation (χ 2=1.87,P= 0.17) and treatment (χ 2=1.83,P= 0.18) were not significantly different between these two groups. The median Frankl scale score was significantly higher in the combination group [3 (3,4)] than in the midazolam group [3 (2,4)] (Z=2.647,P=0.008]. The median score of Houpt scale in the combination group [5(4,6)] was also significantly higher than in midazolam group [5(3,5)] (Z=2.236,P=0.026]. In midazolam group,there were 7 person-times of dysphoria,3 person-times of diplopia,and 2 person-times of hiccough among 78 person-times;in the combination group,there were 5 person-times of dysphoria,5 person-times of diplopia,1 person-time of hiccough,and 2 person-times of vomit among 73 person-times of treatment. Thus,there was no significant difference in the incidence of side effects (15.4% vs.17.8%,χ 2=0.160,P=0.689). Logistic regression analysis showed that the success rate of treatment was not associated with sex (OR=1.704,P=0.174),dose (OR=1.289,P=0.516),and treatment types (OR=0.555,P=0.143). Children over 3 years old had a significantly high success rate than those under 3 years old (OR=3.372,P=0.011). Conclusions Oral midazolam is safe and effective for reducing dental fear in children. The combination of oral midazolam with 30%-40% nitrous oxide can improve the behaviors of children during the dental treatment,especially in children over 3 years old.

Double Roots of Mandibular Premolar in Full-mouth Periapical Films.

OBJECTIVE: To evaluate the incidence of two-rooted mandibular premolar morphology using full-mouth periapical film series in a Chinese population, with particular emphasis on bilateral incidence, so as to provide a clinical anatomical basis for root canal treatment in mandibular premolars. METHODS: A total of 2015 patients who underwent dental treatment and had full mouth periapical radiographs at the Peking University School of Stomatology from April 2011 to April 2012 were enrolled in this study. Three experienced dentists reviewed the patients' periapical films and classified the root morphology of mandibular premolars bilaterally. The incidence of unilateral and bilateral double roots were recorded and calculated, including confirmed and suspected bucco-lingual root types. RESULTS: In terms of the morphology of two-rooted mandibular first premolars, of the 2015 cases with complete root formation, two-rooted first premolars were detected in 120 cases, with a total number of 159 teeth. According to the number of teeth, the overall incidence of double roots was 4.03% (159/3972). In terms of the morphology of two-rooted mandibular second premolars, of the 2015 cases with complete root formation, two-rooted second premolars were detected in 24 cases, with a total number of 33 teeth. According to the number of teeth, the overall incidence of double roots was 0.85% (33/3880). CONCLUSIONS: The roots of mandibular premolars display specific morphological patterns. Based on a large sample, we observed and calculated not only the occurrence rate of bucco-lingual and mesio-distal double roots in first and second mandibular premolars, but also the incidence of unilateral or bilateral double roots within the same mandible. These findings could provide useful information on the anatomical structure of mandibular premolars for endodontic, prosthodontic and surgical procedures, and could improve the quality of treatment and reduce complications.

Reliability and validity of the Chinese version of the Children's Fear Survey Schedule-Dental Subscale.

BACKGROUND: The Children's Fear Survey Schedule-Dental Subscale (CFSS-DS) is a commonly used questionnaire that measures children's dental fears. AIM: This study aimed to examine the reliability and validity of the Chinese version of the CFSS-DS. DESIGN: The CFSS-DS was translated into Chinese and administered to children in a dental office. The sample comprised 206 child patients aged 6-10 years, 42 of whom were selected for test-retest analysis. The behaviors of all 206 children were rated during their dental appointments and compared to their questionnaire results. RESULTS: The internal consistency (Cronbach's α) was 0.85, and the test-retest reliability (intraclass correlation) was 0.71. The Chinese version of the CFSS-DS showed good criterion validity; children who were uncooperative on the Frankl Scale had higher mean CFSS-DS scores (Z = 5.79). Through factorization, three factors emerged: (1) dental treatment, (2) hospital personnel, and (3) invasive dental procedures. Girls reported more fear than boys (21.79 vs 19.91), and children who had painful dental experiences reported more fear (30.87 vs 20.00). CONCLUSION: These results suggest that the CFSS-DS is reliable and valid and operates in China as it does in other cultures. Further studies should include school samples to evaluate children who may not go to the dentist.

Comparison of periodontal ligament anesthesia and submucosal infiltration anesthesia in healthy volunteers.

OBJECTIVE: To compare periodontal ligament anesthesia using a computer-controlled local anesthetic delivery system (C-CLADS) and submucosal infiltration anesthesia using a manually operated syringe in terms of the injection pain, anesthetic effect, anesthetic dose, and complications in healthy volunteers. METHODS: Fifty healthy volunteers, aged 18 to 56 years, were recruited from September 2012 to May 2013 in the Department of Stomatology of Peking Union Medical College Hospital. A randomized self-controlled trial was conducted by applying a periodontal ligament anesthesia on one side and conventional manual submucosal infiltration anesthesia to the other (control) side. The differences in the onset time of anesthesia, drug dosage, anesthetic effect, and the degree of injection pain were compared. The complications associated with the two anesthesia methods were also recorded. RESULTS: When using C-CLADS to perform a periodontal ligament anesthesia, the drug dosage and the severity of injection pain were significantly less than those of conventional manual infiltration anesthesia [drug dosage: (0.34±0.09)ml vs.(0.55±0.13)ml, P<0.01; VRS: 0.42±0.73 vs. 1.38±0.92, P<0.01; VAS: 1.34±1.21 vs. 3.10±1.70, P<0.01]. The anesthesia success rate was approximately 90.0%, showing no significant difference relative to conventional submucosal infiltration anesthesia. Approximately 24% of the volunteers experienced postoperative pain after periodontal ligament anesthesia. CONCLUSION: Compared with conventional submucosal infiltration anesthesia using manual syringes, periodontal ligament anesthesia performed using C-CLADS can reduce the injection pain and drug dosage while achieving a satisfactory anesthetic effect; however, a considerable proportion of cases may experience postoperative pain.

Effectiveness and safety of computer-controlled periodontal ligament injection system in endodontic access to the mandibular posterior teeth.

OBJECTIVE: To evaluate the effectiveness and safety of a computer-controlled periodontal ligament (PDL) injection system to the local soft tissues as the primary technique in endodontic access to mandibular posterior teeth in patients with irreversible pulpitis. METHODS: A total of 162 Chinese patients who had been diagnosed with irreversible pulpitis in their mandibular posterior teeth without acute infection or inflammation in the periodontal tissues were enrolled in this clinical study. The patients were divided into 3 groups according to the position of the involved tooth: the premolar group (PM, n=38), first molar group (FM, n=66), and second molar group (SM, n=58). All the patients received computer-controlled PDL injection with 4% articaine and 1:100 000 epinephrine. Immediately after the injection, endodontic access was performed, and the degree of pain during the treatment was evaluated by the patients using Visual Analogue Scale for pain. The success rates were compared among the 3 groups. The responses of local soft tissues were evaluated 3-8 days and 3 weeks after the procedure. RESULTS: The overall success rate was 76.5%. There was a significant difference in success rates among the PM, FM, and SM groups (92.1%, 53.0%, 93.1%, respectively; χ² = 34.3, P<0.01). Both the PM and SM groups showed higher success rates than that of the FM group (v=1, χ² = 16.73, P<0.01; v=1, χ² = 24.5, P<0.01). No irreversible adverse effects on the periodontal soft tissues at the injection sites were observed in the follow-up visits in any of the groups. CONCLUSION: The computer-controlled PDL injection system demonstrates both satisfactory anesthetic effects and safety in local soft tissues as primary anesthetic technique in endodontic access to the mandibular posterior teeth in patients with irreversible pulpitis.

A new classification of nevus of Ota.

BACKGROUND: The nevus of Ota, is a common benign pigmentary dermatosis, mainly involve innervation area of first and second branch of trigeminal nerve. The classification of nevus of Ota was proposed by Tanino, based on 26 cases of nevus of Ota from 1937 to 1940. Studies about its classification are rarely seen in last 70 years, while it is still practical today. METHODS: Based on the clinical photographs, 1079 consecutive patients with nevus of Ota were verified and reclassified according to the innervation areas of the trigeminal nerve branches. RESULTS: In these 1079 cases, 866 patients were in line with Tanino's classification (80.26%), and 213 patients were not (19.74%). We put forward a new clinical classification (Peking Union Medical College Hospital classification, PUMCH classification) of nevus of Ota based on the innervation area of the trigeminal nerve branches, composed of 5 types and 14 subtypes. The 5 types were as follows: Type I - pigmentation maculeses involving the innervation area of one of the three trigeminal nerve branches, of which there were 424 cases (39.3%), comprising 6 subtypes; Type II - pigmentation macules involving the innervation area of two branches of the three trigeminal nerve branches, of which there were 221 cases (20.48%), comprising 4 subtypes; Type III - pigmentation macules involving the innervation area of all three trigeminal nerve branches, of which there were 361 cases (33.45%), comprising 2 subtypes; Type IV - bilateral type, in which the pigmentation macules involves the bilateral cheek, of which there were 63 cases (5.84%), comprising 2 subtypes; and Type V - complications occurred in the patient, of which there were 10 cases (0.93%). CONCLUSION: The new classification of nevus of Ota is based on the innervation area of the trigeminal nerve branches, and it covers all types of Tanino's classifications; on that basis, some new types and subtypes are brought in and cover almost every clinical condition.

Application of a peripheral nerve block technique in laser treatment of the entire facial skin and evaluation of its analgesic effect.

BACKGROUND: The aim was to develop a technique for peripheral nerve block anesthesia (PNB) for the skin of the entire face and neck, considering the nerves anesthetized, injection sites, use of an injection method assisted by computer-controlled local anesthetic delivery (CCLAD), and to evaluate the analgesic effects of the PNB technique. METHODS: 50 patients who suffered from large nevus of Ota lesions or port-wine stains on their facial and neck skin and who required laser treatment were included. This study was designed as a non-randomized self-control trial. All the patients received the laser treatment under topical anesthesia in the first phase and three to six months later, they received the same treatment under the PNB using CCLAD. The differences in scores from the visual analogue scale of pain for the two phases were analyzed by the t-test. P values <0.05 were considered to be statistically significant. RESULTS: The peripheral nerve block technique was simple to execute and easy to learn, the anesthetic injection site was generally located at a subcutaneous depth of 0.5-1.0 cm. The analgesic effect of PNB was significant, the mean pain score (2.8 ± 2.2) was significantly lower than that with topical anesthesia (P<0.0001). Patients during the PNB phase did not experience injection pain following CCLAD. CONCLUSION: The peripheral nerve block technique can greatly ease the pain that occurs during laser treatment, especially for patients with larger lesions. CCLAD will allow PNB to be broadly applied in laser treatments.

[Evaluation of oral midazolam sedation for reducing dental fear in children with dental fear].

OBJECTIVE: To assess the safety, effectiveness and influential factors of oral midazolam sedation for reducing dental fear in children with dental fear. METHODS: 30 children with traumatic dental experience, who were classified as 1 by Frankl behavior rating scale, were included in the study. Each child was treated under sedation with oral midazolam (0.5-1.0 mg x kg(-1)), and totally 46 person-time sedation treatments were conducted. At each visit, heart rate, arterial oxygen saturation, persistent period and treatment types were recorded. Treatment performed was rated by Houpt scale. Telephone following up was performed to record the side effects 24 h after treatment. RESULTS: In all of the 46 person-time treatments, the heart rate, arterial oxygen saturation levels were within acceptable clinical limits. 37 person-time planned treatments (80.4%) were completed satisfactorily. Oral sedation was ineffective in 9 person-time treatments (19.6%), and only a part of planned treatments were completed. Dysphoria after treatment is the main side effect. Children over 3 years old had a high success rate than those under 3 years old. And the success rate of treatment had no relation with sex, dose and treatment types. CONCLUSION: Oral midazolam could be a safe and acceptable approach of sedation for pediatric dental patients with dental fear, especially to the children over 3 years old.

Multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin.

OBJECTIVE: To investigate whether multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin. METHODS: Twelve caries-free human primary molars were randomly divided into 2 groups. In group 1, each tooth was hemisected into 2 halves. One half was assigned to the control subgroup 1, which was bonded with a commercially available one-step self-etching adhesive according to the manufacturer's instructions; the other half was assigned to experimental subgroup 1, in which the adhesive was applied three times before light curing. In group 2, one split half tooth was bonded with a commercially available one-step self-etching adhesive according to the manufacturer's instructions; for the other half, three layers of adhesive were applied with each successive layer of light curing. Specimens were stored in 0.9% NaCl containing 0.02% sodium azide at 37℃ for 18 months and then were subjected to microtensile bond strength test and the fracture mode analysis. RESULTS: When the adhesive was applied three times before light curing, the bond strength of the experimental subgroup 1 was significantly higher than that of the control subgroup 1 (47.46∓13.91 vs. 38.12∓11.21 MPa, P<0.05). When using the technique of applying multiple layers of adhesive with each successive layer of light curing, no difference was observed in bond strength between the control subgroup and the experimental subgroup (39.40±8.87 vs. 40.87±9.33 MPa, P>0.05). CONCLUSION: Multiple coatings can improve the bond durability of one-step self-etching adhesive to primary dentin when using the technique of light-curing after applying 3 layers of adhesive.

Effect of multiple coatings of one-step self-etching adhesive on microtensile bond strength to primary dentin.

OBJECTIVE: To investigate the effect of multiple coatings of the one-step self-etching adhesive on immediate microtensile bond strength to primary dentin. METHODS: Twelve caries-free human primary molars were randomly divided into 2 groups with 6 teeth each. In group 1, each tooth was hemisected into two halves. One half was assigned to control subgroup 1, which was bonded with a single-step self-etching adhesive according to the manufacturer's instructions; the other half was assigned to experimental subgroup 1 in which the adhesive was applied three times before light curing. In group 2, the teeth were also hemisected into two halves. One half was assigned to control subgroup 2, which was bonded with the single-step self-etching adhesive according to the manufacturer's instructions; the other half was assigned to experimental subgroup 2 in which three layers of adhesive were applied with light curing each successive layer. Microtensile bond strength was immediately tested after specimen preparation. RESULTS: When the adhesive was applied three times before light curing, the bond strength of the experimental subgroup 1 (n=33, 57.49 +/-11.61 MPa) was higher than that of the control subgroup 1 (n=31, 49.71 +/-11.43 MPa, P<0.05). When using the technique of applying multiple layers of adhesive with light curing each successive layer, no difference of immediate bond strength was observed between the control subgroup 2 and the experimental subgroup 2 (P>0.05). CONCLUSION: strength to primary dentin when using the technique of light-curing after applying three layers of adhesive.

[Evaluation of the attention shift effect of a video-audio eyewear in pediatric dental treatment].

OBJECTIVE: To evaluate the attention shift effect produced by a video-audio eyewear in pediatric dentistry. METHODS: Totally 40 children aged 4-7 years were equally randomized into fissure sealant group(group S) and caries filling group(group F). A self-control comparison method was used in each group: each child took two visits to finish the whole study, they received the dental treatment either with normal method(SC, FC) or with attention shift by wearing the video-audio eyewear (SI, FI) for each visit. The degree of pain, accomplishment of treatment, and co-operation were analyzed and compared. RESULTS: All children were successfully managed in the whole course. The pain scores were not significantly different between SC group and SI group or between FC group and FI group (P0.05), while the Frankl scores were significantly different between SC group and SI group (P=0.04) and between FC group and FI group (P=0.03). Houpt scores were significantly different between SC group and SI group (P=0.04), but not between FC group and FI group (P=0.85). Most children (90% in group S) and (85% in group F) expressed the willingness to receive the video-audio eyewear if they were asked to do so again. CONCLUSIONS: The video-audio eyewear provides satisfactory attention shift for children during dental treatment and increases their cooperation. However, it has little effect on pain relieving.

[Management of conscious sedation in dental treatment for asthma patients].

Asthma, often begins in childhood, can affect dental health. In return, dental treatment and dental anxiety can lead to an acute asthmatic attack. This article reviews the potential influence of asthma on dental treatment and dental medications and specifically describes the modes of dental conscious sedation in asthmatic patients.

[Evaluation of oral midazolam conscious sedation in different age groups in pediatric dentistry].

OBJECTIVE: To summarize the effect of oral midazolam sedation in a group of uncooperative patients in pediatric dentistry and analyze the influence of age on treatment results and safety. METHODS: Oral midazolam conscious sedation (dosages range: 0.50 - 0.75 mg/kg) was applied to 109 uncooperative pediatric patients in outpatient department. The patients were divided into two age groups: group A (under 3 years) and group B (over 3 years). Treatment results and safety were statistically analyzed. RESULTS: The mean success rate was 71% (77/109), which was higher in group B [78% (54/69)] than in group A [58% (23/40)]. The incidence of adverse reactions was 17% (19/109), which was higher in group A [28% (11/40)] than in group B [12% (8/69)]. CONCLUSIONS: Oral midazolam conscious sedation at a dosage range of 0.50 - 0.75 mg/kg is more effective and safe in pediatric dental patients over 3 years of age.

[Evaluation of midazolam intravenous sedated patient's comfort degree in mandibular third molar surgery].

OBJECTIVE: To evaluate the clinical efficacy and safety of continuous low-flow intravenous infusion of midazolam sedation in mandibular third molar surgery. METHODS: Fifty healthy patients with symmetrically placed impacted bilateral mandibular third molars were included in this self controlled, randomized clinical study. Degree of comfort (their actual current anxiety level) was assessed using a visual analogue scale (VAS) of pain and anxiety. Patients' satisfaction and degree of amnesia were also evaluated. Vital signs and oxygen saturation were recorded. RESULTS: Low dose midazolam sedation obviously increased the degree of patients' comfort and satisfaction. Vital signs and oxygen saturation levels did not differ significantly between the two groups. CONCLUSIONS: Midazolam as an intravenous sedation agent in mandibular third molar surgery showed satisfactory effect on patients with mild dental fear.

Blood pressure changes of elderly hypertensive patients during dental extraction under sedation with continuous intravenous infusion of midazolam.

OBJECTIVE: To evaluate the changes in blood pressure (BP) of elderly hypertensive patients having dental extraction under sedation with continuous intravenous infusion of midazolam. METHODS: One hundred elderly hypertensive patients undergoing dental extraction were recruited for this single-blind, randomized, controlled study. Patients in intervention group (n = 50) were given midazolam dissolved in glucose solution and patients in control group (n = 50) were given glucose solution only with communication technique. Systolic BP (SBP) and diastolic BP (DBP) were recorded in five time points. RESULTS: Under basal conditions, intervention group did not show significant difference in BP compared with control group. Before sedation, mean values of SBP and DBP (especially SBP) significantly increased compared with basal conditions in both groups (P < 0.05). During dental extraction sessions, mean values of BP in intervention group significantly decreased than control group (P < 0.05), but coefficient of variation did show significant difference in both groups. CONCLUSION: Continuous intravenous infusion of midazolam has been proved to be very successful in controlling BP of elderly patients having dental extraction.

[Continuous intravenous infusion of midazolam: a clinical study of conscious sedation for dental phobia].

OBJECTIVE: To evaluate the sedative effect of continuous intravenous infusion of midazolam in treating severe dental phobia. METHODS: 31 patients with severe dental phobia were enrolled and all of them had good communication with dentists. Two teeth in each patient were assigned to control group and experiment group seperately. The control group received root canal therapy. The experiment group were sedated by intravenous midazolam and received root canal therapy. The treat dependence and behavior therapy efficacy were evaluated. The vital signs and side effects during treatment were noted. RESULTS: Continuous intravenous infusion of midazolam showed a significant good sedative effect on patients with severe dental phobia. There were statistical difference in the Houpt score and the Frankl score between experiment group and control group (z = -4.846, P = 0.000; z = -4.907, P = 0.000). The total dose of midazolam was (9.58 +/- 3.76) mg, and mean infusion rate was (0.28 +/- 0.06) mg x kg(-1) x h(-1). The blood pressure, heart rate and respiration of experiment group were depressed. But these changes didn't interfere with the completion of the whole treatment. No severe side effects were detected. CONCLUSION: The single use of midazolam as an intravenous sedation agent has satisfactory effect on patients with severe dental phobia.