Introduction of integrated dental training jaw models and rubric criteria.

OBJECTIVE: The objective of the present study was to evaluate the effectiveness of introducing integrated jaw models, rubric criteria and homework tasks to a total clinical simulation training course to improve the clinical competence of preclinical dental students. METHODS: A total simulation training course, which involved six clinical dentistry departments, was held for 110 preclinical students in 2014 and 2015. We prepared integrated jaw models having several morbidities along with corresponding medical information and homework tasks. The students formulated diagnoses and devised treatment plans before performing dental treatment on the mannequin under the direction of instructors from the respective clinical departments. Their performance was assessed by both students and instructors using the rubric criteria. RESULTS: Based on quantitative evaluations, the introduction of integrated jaw models appeared to improve the students' ability to formulate diagnoses and devise dental treatment plans and to understand the respective clinical dentistry disciplines. The rubric criteria provided immediate feedback for the students. Based on a comparison of rubric scores, students tended to significantly underestimate their own performance compared with instructors. Moreover, the introduction of homework tasks improved student seriousness. CONCLUSION: Introducing integrated jaw models, rubric criteria and homework tasks to a total simulation training course may be a good approach for improving student performance in terms of dental diagnoses and treatment.

Relation between blood flow and tissue blood oxygenation in human fingertip skin.

BACKGROUND: Tissue blood flow (BF) is thought to be involved in the regulation of tissue blood oxygenation (StO2). The purpose of the present study was to show the relation between BF and StO2 by measuring them simultaneously under different conditions. METHODS: Twenty-one healthy subjects (age 21-30years) participated in this study. We measured BF and StO2 in a small area of skin (fingertip, palm, forearm) simultaneously using a laser Doppler flowmeter and a tissue oxygenation monitor. Three measurements were made at rest while performing mental arithmetic and during constriction of the ipsilateral upper arm. RESULTS: At rest, BF and StO2 were higher in the fingertip than in the palm or forearm (p<0.01). Performing mental arithmetic produced significant decreases in BF, oxygenated hemoglobin, and StO2 in the fingertip (p<0.05). Constriction of the ipsilateral upper arm produced significant decreases in BF and StO2 (p<0.05) and an increase in oxygenated hemoglobin (p<0.05). Both procedures produced significant increases in deoxygenated hemoglobin (p<0.05), which was in antiphase to the decrease in StO2. CONCLUSIONS: BF decrease produced a significantly decreased StO2 in fingertip skin. The results show that simultaneous measurement of BF and StO2 is beneficial for showing the close relation between them.

Improvement of the detection of human pulpal blood flow using a laser Doppler flowmeter modified for low flow velocity.

OBJECTIVE: Human pulpal blood flow (PBF) signals as measured by laser Doppler flowmeter (LDF) decrease with age. Although this decrease is considered to be due in part to slow blood flow, information regarding this velocity in humans has been lacking. The aims of the present study were to estimate the blood flow velocity in human dental pulp and to evaluate the validity of LDF modified for the measurement of slow blood flow. DESIGN: Mean blood flow velocities at the upper central incisor, gingiva, fingertip and forearm of 28 volunteers (mean age: 38.6 years old) were estimated using LDF with a frequency analyser. Blood flow signals at these measurement areas were recorded using two different LDFs: (a) one with a standard blood flow range; and (b) one modified for low blood flow velocity. RESULTS: The frequency range of the Doppler shift measured at the teeth with an opaque rubber dam was the narrowest (median: 4.3kHz) among all of the measurement areas. The estimated mean blood flow velocity was the slowest at the teeth with a dam (median: 0.18mm/s). LDF for low blood flow velocity detected larger and clearer pulsatile blood flow signals from the teeth with dams than did standard LDF. CONCLUSIONS: The present results indicate that the velocity of PBF in humans is very low and that LDF modified for the measurement of slow blood flow is appropriate for PBF measurement in humans.

Revascularization of an immature permanent tooth with periradicular abscess after luxation.

An immature permanent mandibular central incisor with periapical involvement in a 7-year-old boy was treated to promote revascularization. The tooth suffered from acute apical periodontitis after periodontal treatment by a general practitioner. An access cavity was prepared in the tooth and the cavity was left open until the next visit to achieve drainage through the canal. The root canal was not mechanically cleaned during the treatment period, but was irrigated with hydrogen peroxide and sodium hypochlorite. Calcium hydroxide compound was used for disinfection. At the fifth visit vital tissue appeared in the canal near the apical region, and calcium hydroxide compound was placed in contact with the soft tissue in the root canal. The access cavity was sealed with glass-ionomer cement followed by an adhesive composite resin filling. Radiographic examination 30 months after the initial treatment confirmed closure of the apex and thickening of the root wall. The case was observed for up to 13 years and root development was confirmed.

Age-related changes in the human pulpal blood flow measured by laser Doppler flowmetry.

The purpose of this study was to examine the age-related changes in human pulpal blood flow (PBF). Recordings were taken from 22 clinically healthy upper central incisors in 22 healthy participants (age: 8-75 years). A Moor blood flow monitor (type MBF3D) was used to measure PBF; and subjects' electrocardiogram (ECG), mean blood pressure (BP) and heart rate (HR) were also recorded. The resting PBF was significantly decreased with the increased age of the participants (Pearson's correlation coefficient, P < 0.001). The examined tooth crown was briefly(1 s) cooled using a dental coolant, and significant reductions in PBF were induced (one-way repeated measures anova, P < 0.05). The magnitude of the reduction (%) was significantly decreased with the increased age of the participants (Pearson's correlation coefficient, P < 0.05). The findings indicate that the hemodynamics in the human pulp is reduced with age.

The effect of continuous intrusive force on human pulpal blood flow.

The purpose of this study was to examine the effect of continuous intrusive force application on human pulpal blood flow (PBF). Recordings were made of 13 vital upper left central incisors in 13 healthy participants (experimental group, n = 8; control group, n = 5) who had clinically healthy tooth crowns and periodontal tissues. PBF was recorded by means of a laser Doppler flow meter (LDF) with an opaque rubber dam applied to the teeth. The basal blood flow in the pulp (BBFP) was compared during three observation periods: (1) before orthodontic archwire engagement; (2) during wire engagement (control group: no application of force; experimental group: continuous intrusive force of 0.5 N); and (3) after the removal of the wire. In the experimental group, brief intrusive forces (magnitude 0.5, 1.0, and 2.0 N) were applied to the incisal edge of the examined teeth to determine their effect on acute changes in PBF. The results obtained were as follows: (1) the BBFP in the experimental group was significantly reduced during the period of continuous intrusive force application (P < 0.05), which was followed by recovery after the removal of the wire. (2) Brief intrusive force produced a significant reduction of PBF (P < 0.05), but the reduction rate (percentage) did not differ significantly during the observation periods. The results indicate that the measurement technique shown in this study could detect PBF change produced by continuous orthodontic force application.

Treatment of gingival overgrowth induced by manidipine administration. A case report.

BACKGROUND: It is well known that severe gingival overgrowth (GO) is induced in patients taking certain calcium channel blockers (CCB) for the treatment of hypertension, angina pectoris, and other diseases. No case has been reported to date of severe GO induced by manidipine hydrochloride (manidipine), a second generation CCB. This case report describes severe GO induced by manidipine in a female patient (43 years old) with hypertension and Sjögren syndrome (SS). The patient was administered manidipine and carteolol hydrochloride (carteolol) as antihypertensive drugs, together with bromhexine hydrochloride for the treatment of SS. METHODS: At the initial periodontal examination, probing depth (PD, average 4.83 mm), plaque control record (PCR, 84.3%), bleeding on probing (BOP, 100%), and gingival overgrowth index (GOI, 2.42) were assessed. The patient received periodontal treatment without cessation or replacement of the causative drug. Initial treatment included oral hygiene and scaling and root planing (SRP) under local anesthesia. As corrective therapy, remaining pockets were surgically removed and fixed bridges placed to establish proper occlusion. RESULTS: Obvious reductions in PCR (10.0%), PD (1.93 mm), GOI (0.02), and BOP (4.7%), together with a disappearance of GO, were obtained. Salivary secretion was increased after the periodontal and prosthetic treatments. Histological features were similar to those of nifedipine-induced GO. CONCLUSIONS: This case indicated that manidipine may act as a potent inducer of severe GO, and that conventional periodontal treatments without a major change of the causative drugs can yield satisfactory clinical responses.

Pulpal blood flow in vital and nonvital young permanent teeth measured by transmitted-light photoplethysmography: a pilot study.

PURPOSE: The purpose of this study was to record transmitted-light photoplethysmography (TLP) from young permanent teeth and examine its applicability to pulp vitality assessment. METHODS: Twenty-six healthy and 7 nonvital upper maxillary incisors in 17 children (ages 7 years, 3 months to 14 years, 8 months) were examined. Recordings of TLP were made with and without opaque black rubber dam application in a darkened room. Finger photoplethysmography (FPP) of the participants was simultaneously recorded. RESULTS: (1) Pulse waves synchronous with FPP were recorded from all healthy teeth, whereas no pulse signals were recognized in nonvital teeth. (2) The signal amplitude in the TLP was not significantly affected by the opaque dam application. (3) In the healthy teeth, there was a significantly negative correlation between the TLP pulse amplitude and the age of the subjects. CONCLUSIONS: TLP can detect pulpal blood flow in young permanent teeth. This technique is considered to be applicable in the assessment of pulp vitality.