This study aims to introduce the method that can relieve vibrating forces to oral environment by making an embouchure aid. Thin plastic crown forms were fabricated to prevent tooth abrasion and irritation to lip mucosa for the saxophone player. After application to the player, the most comfort form was chosen and delivered to 3 professional saxophone players. After 5 mon, the players responded to the survey. This embouchure aid did not disturb playing and gave comfort to lower lip. In general, the players preferred thin soft type and thought it caused little effect on sound. Far too little attention has been paid to the problems encountered by single-reed wind instrumentalist who suffer from tooth abrasion and irritation to lip mucosa. The embouchure aid not only prevent tooth damage but also diminish the discomfort of tight embouchure.

The purpose of this study was to evaluate the viability of periodontal ligament cells of rat teeth after low-temperature preservation under high pressure by means of MTT assay, WST-1 assay. 12 teeth of Sprague-Dawley white female rats of 4 week-old were used for each group.

Both side of the first and second maxillary molars were extracted as atraumatically as possible under tiletamine anesthesia. The experimental groups were group 1 (Immediate extraction), group 2 (Slow freezing under pressure of 3 MPa), group 3 (Slow freezing under pressure of 2 MPa), group 4 (Slow freezing under no additional pressure), group 5 (Rapid freezing in liquid nitrogen under pressure of 2 MPa), group 6 (Rapid freezing in liquid nitrogen under no additional pressure), group 7 (low-temperature preservation at 0℃ under pressure of 2 MPa), group 8 (low-temperature preservation at 0℃ under no additional pressure), group 9 (low-temperature preservation at -5℃ under pressure of 90 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in 37℃ water bath, then MTT assay, WST-1 assay were processed. One way ANOVA and Tukey HSD method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization.

In both MTT and WST-1 assay, group 7 (0℃/2 MPa) showed higher viability of periodontal ligament cells than other group (2-6, 8) and this was statistically significant (p < 0.05), but showed lower viability than group 1, immediate extraction group (no statistical significance).

By the results of this study, low-temperature preservation at 0℃ under pressure of 2 MPa suggest the possibility for long term preservation of teeth.

This study examined the influence of the storage methods on the viability of oral epithelial cells using conventional cell freezing storage, slow freezing preservation, rapid freezing preservation, and slow freezing preservation with a pressure of 2 Mpa or 3 Mpa. The cell viability was evaluated by cell counting, WST-1 and the clonogenic capacity after 6 days of freezing storage. After 6 days, the frozen cells were thawed rapidly, and the cell counting, WST-1, and clonogenic capacity values were measured and compared.

The results from cell counting demonstrated that conventional cryopreservation, slow freezing under a 2 Mpa pressure and slow freezing under a 3 Mpa pressure showed significantly higher values than slow freezing preservation and rapid freezing preservation (p<0.05).

The aim of this study was to evaluate endodontic irrigation methods with EndoVac^® and EndoActivator^® in the elimination of Enterococcus faecalis from the root canals. Extracted 70 human single-rooted teeth were used. The canals were instrumented by a crown-down technique with .04 taper ProFile to ISO size 40. After the teeth were autoclaved, the canals were inoculated with E. faecalis and incubated for 48 h. The teeth were randomly divided into three experimental groups of 20 teeth each according to canal irrigation methods and two control groups as follows: group 1 - EndoVac^®; group 2 - EndoActivator^®; group 3 - Conventional needle irrigation method. After canal irrigation using 2.5% NaOCl, first samples (S1) were taken using sterile paper point. And the canals were filled with sterile brain heart infusion (BHI) broth and incubated for 24 h, then second samples (S2) were taken. The samples were cultured on BHI agar plate to determine the numbers of colony forming units (CFU). In first sampling (S1), only one canal of conventional method among the all experimental groups was positive cultured. In second sampling (S2), EndoVac^® group showed the least positive culture numbers of E. faecalis. There was statistically significant difference between the EndoVac^® and conventional needle irrigation methods in the mean value of Log CFU. According to the results of this study, EndoVac^® showed better efficacy than conventional needle irrigation method in the elimination of E. faecalis from the root canal.

The purpose of this study was to evaluate the viability of periodontal ligament cells in rat teeth using slow cryo-preservation method under pressure by means of MTT assay and WST-1 assay. Eighteen teeth of Sprague-Dawley white female rats of 4 week-old were used for each group.

Both sides of the first and second maxillary molars were extracted as atraumatically as possible under Tiletamine anesthesia. The experimental groups were group 1 (Immediate control), group 2 (Cold preservation at 4°C for 1 week), group 3 (Slow freezing), group 4 (Slow freezing under pressure of 3 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in 37°C water bath, then MTT assay and WST-1 assay were processed. One way ANOVA and Tukey method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization.

In both MTT and WST-1 assay, group 4 showed significantly higher viability of periodontal ligament cells than group 2 and 3 (p < 0.05), but showed lower viability than immediate control group.

By the results of this study, slow cryo-preservation method under pressure suggests the possibility for long term cryo-preservation of the teeth.

The aim of this study was to measure and compare the micro shear bond strengths of the following dentin bonding systems to the dentin surfaces under simulated pulpal pressure; All Bond 2®, Second®, AdheSE®, Adper Prompt L-Pop®. The occlusal surfaces of 180 extracted human molars were prepared so the dentin bonding surfaces could be exposed. The teeth were randomly assigned to 3 equal groups of 60 each and subdivided. The dentin surfaces were treated with the above mentioned bonding system and resin composite cylinders were built up under a simulated pulpal pressure when saline (Group II) or diluted bovine serum (Group III) was used as the pulpal fluid. As a control, the same procedures were performed in the dried dentin surfaces (Group I). After one day of storage in water, the micro shear bond strengths were measured using an EZ tester. Group II and III showed significantly lower shear bond strength than Group I statistically (p < 0.05). SEbond® and AdheSE® showed no difference among the different dentin condition. In the Adper Prompt L-Pop®, a simulated pulpal pressure were applied to the specimens using diluted bovine serum, which showed a higher strength than the specimens in which saline was used (p < 0.05).