• 구강회복응용과학지
• /
• 제22권3호
• /
• pp.231-242
• /
• 2006

Statement of problem: The sealing of the opened dentinal tubules that follows the tooth preparation for the prosthodontic restoration is considered as clinical process to reduce postoperative sensitivity. Purpose: This study investigated the effect of desensitization treatment on shear bond strength of luting cements. Materials and Method: Total 80 dentin specimens were divided into two groups according to the kinds of luting cements. Each groups was further divided into 4 subgroups with AQ $bond^{(R)}$, $Saforide^{(R)}$, Diode laser $MDL-10^{(R)}$ application and without desensitization treatment. After desensitization treatment application, Ni-Cr specimens were luted to dentin surface with Fuji $CEM^{(R)}$ and $Panavia-F^{(R)}$. Specimens were placed in distilled water at $37^{\circ}C$ for 24 hours and shear bond strength between metal and dentin was measured by a universal testing machine. Results: 1. In Fuji $CEM^{(R)}$ cemented groups, the combination of AQ $bond^{(R)}$ showed the greatest strength, followed by diode laser, no desensitizer treatment, and $Saforide^{(R)}$. Both AQ $bond^{(R)}$ and Diode laser groups had a significant difference than no desensitization treatment group and $Saforide^{(R)}$ group(p<0.05). 2. In $Panavia-F^{(R)}$ cemented groups, the combination of Diode laser showed the greatest strength, followed by AQ $bond^{(R)}$, $Saforide^{(R)}$, and No desensitization treatment. All desensitization treatment groups had a significant difference than no desensitization treatment group(p<0.05). 3. All $Panavia-F^{(R)}$ groups showed a significant higher shear bond strength than all Fuji $CEM^{(R)}$ groups(p<0.05). Conclusion: The results of this study showed possibility of bond strength increase after desensitization treatment. The application of desensitization treatments like AQ $bond^{(R)}$, $Saforide^{(R)}$, and Diode laser $MDL-10^{(R)}$ have advantages in exposed dentin surface after tooth prep.

• 센서학회지
• /
• 제32권5호
• /
• pp.320-327
• /
• 2023

In this study, an FPGA-based sealer inspection system was developed to inspect the sealer applied to install vehicle glass on a car body. The sealer is a liquid or paste-like material that promotes adhesion such as sealing and waterproofing for mounting and assembling vehicle parts to a car body. The system installed in the existing vehicle design parts line does not detect the sealer in the glass rotation section and takes a long time to process. This study developed a line laser camera sensor and an FPGA vision signal processing module to solve this problem. The line laser camera sensor was developed such that the resolution and speed of the camera for data acquisition could be modified according to the irradiation angle of the laser. Furthermore, it was developed considering the mountability of the entire system to prevent interference with the sealer ejection machine. In addition, a vision signal processing module was developed using the Zynq-7020 FPGA chip to improve the processing speed of the algorithm that converted the profile to the sealer shape image acquired from a 2D camera and calculated the width and height of the sealer using the converted profile. The performance of the developed sealer application inspection system was verified by establishing an experimental environment identical to that of an actual automobile production line. The experimental results confirmed the performance of the sealer application inspection at a level that satisfied the requirements of automotive field standards.

• 한국압력기기공학회 논문집
• /
• 제16권1호
• /
• pp.84-91
• /
• 2020

The APR1400 reactor stud holes can be stuck due to high temperatures, high pressure, prolonged engagement, and load changes according to pressure changes in the reactor. Threaded surfaces of a stud hole should be cleaned for the sealing of pressure in reactor vessel by removing any foreign materials which may exist in the stud holes. Human workers can access to the stud hole for the cleaning of stud holes manually, but the radiation exposure of human workers is increased. Robot is an effective way to work in hazardous area. So we introduced robot for the cleaning of stud holes. Localization of mobile robots is generally based on odometry, but with increased mileage, position errors can be accumulated. In order to eliminate cumulative error and to ensure stability of its driving, laser sensors and new control algorithm were utilized. The distance between the robot and the wall was measured by laser sensors, and the control algorithm was implemented so as to travel the desired trajectory by using the measured values from sensors. The performance of driving and hole sensing were verified through field application, and mobile robot was confirmed to be applicable to the APR 1400 NPP.

• 한국마이크로전자및패키징학회:학술대회논문집
• /
• 한국마이크로전자및패키징학회 2003년도 기술심포지움 논문집
• /
• pp.239-242
• /
• 2003

Optical module package is a hermetic metal-ceramic package for carrying optical IC. In case of LD(laser diode) module, window is used for both the path of optical signal and hermetic sealing of package. So, window has the metallization pattern on the surface for brazing process with package wall. In this study, several method were investigated for metallization. Thin film, thick film and mixed method were used for fabrication of metallization pattern. After brazing process, hermeticity and adhesion strength were tested for characterization of metallization pattern.

• Journal of Periodontal and Implant Science
• /
• 제45권3호
• /
• pp.120-126
• /
• 2015

Purpose: With the significance of stable adhesion of alveolar bone and peri-implant soft tissue on the surface of titanium for successful dental implantation procedure, the purpose of this study was to apply microgrooves on the titanium surface and investigate their effects on peri-implant cells and tissues. Methods: Three types of commercially pure titanium discs were prepared; machined-surface discs (A), sandblasted, large-grit, acid-etched (SLA)-treated discs (B), SLA and microgroove-formed discs (C). After surface topography of the discs was examined by confocal laser scanning electron microscopy, water contact angle and surface energy were measured. Human gingival fibroblasts (hGFs) and murine osteoblastic cells (MC3T3-E1) were seeded onto the titanium discs for immunofluorescence assay of adhesion proteins. Commercially pure titanium implants with microgrooves on the coronal microthreads design were inserted into the edentulous mandible of beagle dogs. After 2 weeks and 6 weeks of implant insertion, the animal subjects were euthanized to confirm peri-implant tissue healing pattern in histologic specimens. Results: Group C presented the lowest water contact angle ($62.89{\pm}5.66{\theta}$), highest surface energy ($45{\pm}1.2mN/m$), and highest surface roughness ($Ra=22.351{\pm}2.766{\mu}m$). The expression of adhesion molecules of hGFs and MC3T30E1 cells was prominent in group C. Titanium implants with microgrooves on the coronal portion showed firm adhesion to peri-implant soft tissue. Conclusions: Microgrooves on the titanium surface promoted the adhesion of gingival fibroblasts and osteoblastic cells, as well as favorable peri-implant soft tissue sealing.