The autotransplantation of an anklyosed maxillary canine / 대한치과보존학회지

The clinical diagnosis of ankylosis can be made only when the affected tooth gives positive evidence of an inability to move. The inability to move is demonstrated either as a failure of the tooth to move with normal vertical dental alveolar growth or a failure of the tooth to move when the tooth is subjected to an orthodontic force system. This case report describes the autotransplantation of an ankylosed maxillary canine.

Root canal treatment of a mandibular second premolar with three separate root canals / 대한치과보존학회지

Mandibular premolars show a wide variety of root canal anatomy. Especially, the occurrence of three canals with three separate foramina in mandibular second premolars is very rare. This case report describes the root canal treatment of an unusual morphological configuration of the root canal system and supplements previous reports of the existence of such configuration in mandibular second premolar.

Mouthguard for relief of repeated clenching stress to cervical restorations during exercises / 대한치과보존학회지

Mouthguards were used to protect boxers from lip lacerations and other soft tissue injuries in the late 19th century. Now they are used various parts of dental treatment, which are sports protective aid, bleaching tray, orthodontic retainer, implant insertion guide tray, splint and so on. Repeated dislodgement of Class V restoration due to habitual clenching stress should be restored with stress control. Mouthguard can be used as stress relief device. This case describes methods that can relieve occlusal force to teeth by using mouthguard. Satisfactory results can be obtained by using mouthguard for retention of repeated dislodgement Class V restorations. If patients suffered from repeated restorations of Class V due to clenching, mouthguard can be used additional device to relieve the occlusal stress in conservative dentistry.

Effect of infection control barrier thickness on light curing units / 대한치과보존학회지

OBJECTIVES: This study investigated the effect of infection control barrier thickness on power density, wavelength, and light diffusion of light curing units. MATERIALS AND METHODS: Infection control barrier (Cleanwrap) in one-fold, two-fold, four-fold, and eight-fold, and a halogen light curing unit (Optilux 360) and a light emitting diode (LED) light curing unit (Elipar FreeLight 2) were used in this study. Power density of light curing units with infection control barriers covering the fiberoptic bundle was measured with a hand held dental radiometer (Cure Rite). Wavelength of light curing units fixed on a custom made optical breadboard was measured with a portable spectroradiometer (CS-1000). Light diffusion of light curing units was photographed with DSLR (Nikon D70s) as above. RESULTS: Power density decreased significantly as the layer thickness of the infection control barrier increased, except the one-fold and two-fold in halogen light curing unit. Especially, when the barrier was four-fold and more in the halogen light curing unit, the decrease of power density was more prominent. The wavelength of light curing units was not affected by the barriers and almost no change was detected in the peak wavelength. Light diffusion of LED light curing unit was not affected by barriers, however, halogen light curing unit showed decrease in light diffusion angle when the barrier was four-fold and statistically different decrease when the barrier was eight-fold (p < 0.05). CONCLUSIONS: It could be assumed that the infection control barriers should be used as two-fold rather than one-fold to prevent tearing of the barriers and subsequent cross contamination between the patients.

Physical properties of different self-adhesive resin cements and their shear bond strength on lithium disilicate ceramic and dentin / 대한치과보존학회지

The purpose of this study was to evaluate the physical properties of different self-adhesive resin cements and their shear bond strength on dentin and lithium disilicate ceramic and compare these result with that of conventional resin cement. For this study, four self-adhesive resin cements (Rely-X Unicem, Embrace Wetbond, Mexcem, BisCem), one conventional resin cement (Rely-X ARC) and one restorative resin composite (Z-350) were used. In order to evaluate the physical properties, compressive strength, diametral tensile strength and flexural strength were measured. To evaluate the shear bond strength on dentin, each cement was adhered to buccal dentinal surface of extracted human lower molars. Dentin bonding agent was applied after acid etching for groups of Rely-X ARC and Z-350. In order to evaluate the shear bond strength on ceramic, lithium disilicate glass ceramic (IPS Empress 2) disks were prepared. Only Rely-X ARC and Z-350 groups were pretreated with hydrofluoric acid and silane. And then each resin cement was adhered to ceramic surface in 2 mm diameter. Physical properties and shear bond strengths were measured using a universal testing machine. Results were as follows 1. BisCem showed the lowest compressive strength, diametral tensile strength and flexural strength. (P<0.05) 2. Self-adhesive resin cements showed significantly lower shear bond strength on the dentin and lithium disilicate ceramic than Rely-X ARC and Z-350 (P<0.05) In conclusion, self-adhesive resin cements represent the lower physical properties and shear bond strength than a conventional resin cement.

Management of fibrous hyperplasia in oral mucosa / 대한치과보존학회지

There are a number of situations where the oral mucosa can be sucked or pressed to produce relatively banal but clinical distinctive changes. The labial and buccal mucosa and tongue may develop protuberances in areas where a tooth is missing or extra space is present. The mucosa is pressed and sucked into these spaces, thus leading to the development of a fibrous hyperplasia. This case report describes the management of fibrous hyperplasia in oral mucosa. Fibrous hyperplasia can be formed by habitual pressure or suction in oral mucosa. Treatment of fibrous hyperplasia consists of simple excision and, if feasible, elimination of the cause. And habit control is a important factor for preventing recurrence.