The purpose of this study was to evaluate the effect of oral environment on the strength of resin bracket wings by comparing fracture mode according to water immersion and thermocycling. Seventy-five resin brackets(Spirit MB, Ormco, California) were divided into three groups and treated for six months as follows; (1) untreated, (2) water immersion in distilled water at 37degrees C, (3) water immersion in distilled water at 37degrees C with total 2,100 times of thermocyeling taken 350 times each month. Fracture mode of the wing was tested on universal testing machine. In addition to resin brackets, 25 metal brackets were used as controls. Through the statistical analyses, following results were obtained. 1. Resin bracket wings showed significantly lower fracture strength than metal brackets(p<0.001). 2. Water immersion and water immersion with thermocycling groups showed significantly lower fracture strength than open air condition group(p<0.001). 3. Water immersion with thermocycling group showed significantly lower fracture strength than water immersion group(p<0.001). The above results sugg est that the mechanical property of resin bracket wing may be influenced by oral environment and further research is needed to improve the strength of the wing in the resin bracket.
Immersion* ; Water*

OBJECTIVE: To explore the healing effect of low intensity pulsed ultrasound with three different timing of intervention after tenotomy of Achilles tendon in rats. METHOD: One hundred and thirty-two male rats were divided into experimental and control groups. Both groups were classified according to treatment phase: treatment on inflammatory phase (group I), proliferative phase (group II), and maturation phase (group III). Each groups were divided into 2 subgroups according to tendon excision time: 1 day after 7 consecutive treatment on 3 different phases (I-A, II-A, and III-A) and 30 days after tenotomy (I-B, II-B, and III-B). Three MHz pulsed ultrasound was administered on right tendon for 4 mins at 0.5 W/cm2. The excised tendons of all groups were compared histologically and biochemically as control. RESULTS: The tendons of II-A experimental group revealed increased fibroblasts. The collagen fibers in the neo-tendon of II-B and III-B experimental groups had a tendency to be arrayed more regularly. On I-A group, the neo-tendon showed high immunoreactivity for type I and particularly type III collagen in cytoplasm of fibroblasts and collagen fibers. The imunoreactivity for type III collagen in the neo-tendon of II-A experimental group increased than control. The concentration of collagen of the neo-tendon was significantly increased on I-A and II-A experimental groups compared with control (p<0.05). Collagen concentration of the neo-tendon of II-B experimental group increased significantly compared with control and I-B and III-B experimental groups (p<0.05). CONCLUSION: These results suggest that low intensity pulsed ultrasound therapy on injured Achilles tendon may be of benefit such as increasing collagen synthesis in the early healing process, especially in proliferative phase.
Achilles Tendon* ; Animals ; Collagen ; Collagen Type III ; Cytoplasm ; Fibroblasts ; Humans ; Male ; Rats* ; Tendons ; Tenotomy ; Ultrasonography*

No abstract available.
Burkholderia cepacia* ; Skin*

OBJECTIVE: The purposes of this study were to obtain the reference values of latency and amplitude of the medial plantar sensory nerve action potential(SNAP) in normal controls and to evaluate the diagnostic sensitivity of medial plantar sensory nerve conduction study(NCS) in diabetic neuropathy. METHOD: Thirty healthy controls(mean age, 48.7 years; range, 38~59 years) and 33 diabetic patients(mean age, 50.8 years; range, 37~64 years) were included in this study. The inclusion criteria for diabetic patients were subjects with the normal peroneal and tibial compound muscle action potentials, obtainable sural SNAPs and intact pressure-perception to Semmes-Weinstein monofilament 5.07. RESULTS: The medial plantar sensory nerve action potentials were obtainable in all control subjects and the reference values of onset latency and peak to peak amplitude were 4.29+/-0.49 msec and 3.1+/-1.34 V, respectively. All 33 diabetic patients showed the normal latency and 3 of them showed the low amplitude in sural SNAPs. The medial plantar SNAPs were obtainable in 24 diabetic patients. Among 9 patients with unobtainable medial plantar SNAPs, 6 showed the normal sural SNAPs and 3 showed the low sural SNAPs. The sensitivities of medial plantar SNAPs to sural nerve and sural SNAPs to medial plantar sensory nerve were 100%(3/3) and 27.3%(3/11) respectively. CONCLUSION: We concluded that medial plantar sensory NCS was more valuable in the early diagnosis of diabetic neuropathy than the sural NCS and Semmes-Weinstein monofilament (North Coast Medical Inc, USA).
Action Potentials ; Diabetic Neuropathies ; Early Diagnosis ; Humans ; Neural Conduction* ; Reference Values ; Sural Nerve ; Tibial Nerve

OBJECTIVE: To assess the facial and trigeminal nerve involvement in diabetic patients using blink reflex study and direct facial motor conduction study. METHOD: The subjects were 397 diabetic patients and 34 normal controls. Diabetic patients were subdivided into two groups based on the findings of nerve conduction studies of limb nerves.: Group I, patients with diabetic polyneuropathy; Group II, patients without diabetic polyneuropathy. The blink reflexes and direct facial motor responses and R1 latency/direct response latency (R/D) ratio were obtained in all the subjects. R1 latency was correlated to the findings of nerve conduction studies of limb nerves. RESULTS: 1) R1 latencies or R2 latencies were abnormally prolonged in 22.4% of Group I, 3.3% of Group II, and direct facial responses were abnormal in 11.8% of Group I, 2% of Group II. 2) There were no significant differences in R/D ratio between the two groups. 3) These findings suggest that not only the facial nerve, but also the trigeminal nerve or brain stem could be affected in diabetic patients with polyneuropathy. CONCLUSION: In diabetic patients, blink reflex can provide useful information in determining the degree and distribution of cranial nerve and brain stem lesions.
Blinking* ; Brain Stem ; Cranial Nerves ; Diabetes Mellitus ; Diabetic Neuropathies ; Extremities ; Facial Nerve ; Humans ; Neural Conduction ; Polyneuropathies ; Reaction Time ; Trigeminal Nerve

The dental gold alloy shows a lower bond strength than the natural teeth in bracket bonding, and this can be a possible source of subsequent bond failure. This study aims to evaluate the effect of various gold alloy surface treatment techniques on shear bond strength between the orthodontic adhesives and the gold alloy and to find ways of increasing the bond strength. Two hundred and forty specimens made of the dental gold alloy were divided into twelve groups based on the combination of surface treatment methods(non-surface treatment, sandblasted, sandblasted plus tin-plated, and sandblasted plus intermediate adhesive) and adhesive systems (Ortho-one, Panavia 21, Superbond C&B). The specimens with bonded brackets were placed in distilled water at 37degrees C for 24 hours and shear bond strength was measured by a universal testing machine. The results were as follows: 1. All surface-treated groups showed a significantly higher shear bond strength than non-surface-treated groups. 2. The sandblasted plus tin-plated grout showed a significantly higher shear bond strength than the sandblasted group only when Panavia 21 was involved. 3. The sandblasted plus intermediate adhesive group showed a significantly higher shear bond strength than sandblasted group regardless of the type of adhesive used. 4. Of.the three resin adhesive types, the Superbond C&B showed the highest bond strength, followed by Panavia 21 and Ortho-one. These findings suggest that a combination of sandblasting and intermediate resin treatment is desirable in order to enhance bracket bond strength regardless of adhesive types.
Adhesives ; Alloys* ; Dental Cements ; Orthodontic Brackets* ; Tooth ; Water

OBJECTIVE: The purpose of this study was to examine the effect of ipriflavone on periodontal reorganization and prevention of relapse following tooth movement. METHODS: Orthodontic rubber bands were inserted between the first and second maxillary molars of 27 white male rats for 3 weeks for experimental tooth movement. From one day before the removal of orthodontic rubber band, ipriflavone was administered 50 or 400 mg/kg daily in each experimental group whereas carboxymethyl cellulose solution was administered in the control group. They were sacrificed at the 5, 10, and 15th day from the day of removal of orthodontic rubber bands. The amount of relapse was evaluated by measuring the interdental space, and the extent of periodontal reorganization was compared through histological examination. RESULTS: In case of ipriflavone administration, the amount and velocity of relapse was less and slower compared to the control group. In addition, the ipriflavone group showed more rapid periodontal reorganization compared to the control group. CONCLUSIONS: The results of the present study suggest that ipriflavone administration can be used effectively in the prevention of relapse following orthodontic tooth movement through the acceleration of periodontal reorganization.
Acceleration ; Animals ; Carboxymethylcellulose Sodium ; Humans ; Isoflavones ; Male ; Molar ; Rats ; Recurrence ; Rubber ; Tooth ; Tooth Movement

Background: Dental caries in preschool children can cause early loss of teeth, reduced masticatory function, malocclusion, and speech disorders, making oral care for preschool children essential. However, because children have a poor ability to perform oral hygiene by themselves, educational tools that help establish correct oral health behaviors are required. This study evaluated the effect of toothbrushing application for kids on dental plaque removal and toothbrushing interest in preschool children. Methods: Seven 5-year-old children enrolled in a daycare center participated in the evaluation, and the same children participated in the experiment twice a week. The Pokémon Smile application (App) was used as an auxiliary application for tooth brushing, and the degree of dental plaque removal on the tooth surface was evaluated by quantitative light-induced fluorescence-digital imaging. After the experiment, children’s toothbrushing preferences were investigated through interviews. Results: The levels of AREA R30 and AREA R70 measured after the children’s toothbrushing as usual decreased compared to those before toothbrushing; however, the change was not significant. The levels of AREA R30 and AREA R70 measured after using the Pokémon Smile App were significantly reduced compared to those before toothbrushing. Children’s interest in brushing their teeth increased by 28.59% after using the Pokémon Smile App. Conclusion The toothbrushing application for kids effectively removes dental plaque by helping preschool children brush their teeth. It also increased preschool children’s interest in tooth brushing. Therefore, an oral health education application would be useful for children who need to develop correct oral care methods and habits.

In the case of crown-root fracture due to traumatic injury in anterior tooth and the fracture margin is located subgingivally,forced eruption has been proposed for the reconstruction of deficient bone and soft tissue. Forced eruption is one of the easiestorthodontic approaches that can have an acceptable outcome and prognosis, and has a low incidence of relapse. However, using heavy forces or very fast movements can also cause tissue damage or ankylosis. The following case reports present forced eruption as treatment option of crown fracture in maxillary anterior teeth.