• Proceedings of the Optical Society of Korea Conference
• /
• 1988.06a
• /
• pp.37-40
• /
• 1988

보조전극을 사용하여 전기방전을 궤환 조절하여 연속출력 탄산가스 출력을 안정화하였다. 보조전극은 양극과 접지되어 있는 음극사이에서 음그근처에 설치하였으며 레이저 출력을 HgCdTe-detector로 측정하여 레이저 출력의 요동에 따라 보조전극에 인가되는 전압이 변화되도록 하였다. 보조전극을 사용하여 레이저 출력을 안정화시킨 결과 레이저 출력의 요동은 안정화하지 않았을때의 레이저출력 요동의 1/10 이하로 감소하였다.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.33 no.2
• /
• pp.201-206
• /
• 2006

A recent laboratory study has demonstrated improved caries lesion resistance with enamel that was exposed to $CO_2$ laser irradiation for very short time period. When topical fluoride treatment was performed before or after laser irradiation, reductions in dental caries. The purpose of this scanning electron microscopic(SEM) study and atomic force microscope study was to characterize surface alterations in tooth enamel after in vitro laser irradiation alone and combined topical fluoride treatment either before or after laser irradiation. The treatment effects of laser irradiation led to the formation of an irregular, mild porosities and fine fissures, also created granular materials. But when laser irradiation was followed by APF, the enamel surface had homogenous architecture. The result led to the caries resistance effects by these granular structures have been considered to represent redeposited mineral phases due to the mobilization of calcium, phosphate, and fluoride from lased enamel.

• Korean Journal of Optics and Photonics
• /
• v.3 no.4
• /
• pp.234-238
• /
• 1992

A sealed-off waveguide $CO_2$ laser with a length of 50 cm and a cross-sectional area of $6\times 6\ttextrm{mm}^{2}$ has been designed and constructed. The laser is transversely excited by RF (13.56 MHz) discharge. Output characteristics of the laser has been investigated performing variations of total gas pressure, input rf power, and mixing ratios of gases. The maximum output power of 9.5 W was obtained under the condition of total gas pressure of 50 Torr, input rf power of 180 W, and gas mixture of 6 : 1 : 2 : 1 of $He:CO_{2}:N_{2}:Xe$.

• Proceedings of the KSME Conference
• /
• 2005.11a
• /
• pp.206.1-206.1
• /
• 2005

• Journal of Oral Medicine and Pain
• /
• v.35 no.3
• /
• pp.177-182
• /
• 2010

Conventional surgical therapy for oral soft tissue includes the use of scalpel, diathermy, cryotherapy and electrosurgery. But, these therapies have some surgical problems. Nowadays, laser surgery can be considered as the another option for conventional surgical therapy. Compared to conventional surgical therapies, advantages of laser therapy include maintenance of sterile conditions, promotion of wound healing, reduction of bleeding, less instruments, post operative pain reduction, less scar, saving cost by using fewer materials, staff and time. Carbon dioxide ($CO_2$) laser uses gaseous medium, and has long wavelength about 10,600nm. The first advantage of $CO_2$ laser for surgical treatment of oral soft tissue is hemostasis and visibility improvement by making relatively dry field. These case reports are about cases of minor surgery of oral soft tissue using $CO_2$ laser, and emphasize advantages of laser compared to conventional surgical therapies.

• Korean Journal of Bronchoesophagology
• /
• v.4 no.2
• /
• pp.159-164
• /
• 1998

The developmental and subsequent addition of laser technology to existing surgical techniques offered new and exciting Possibilities for improving traditional endoscopic operations and expanding the scope of the specialty of otolaryngology-head and neck surgery. Lasers were found to be Precise, but potentially dangerous, surgical instruments whose use was associated with certain distinct and unprecedented advantages, but also with many unique and potentially serious, and sometimes catastrophic complications. The Purpose of this study was to evaluate the of elation technique of $CO_2$laser, kinds of anesthesia, equipments of operating room, and education of medical staff. Four hundreds 4 cases of $CO_2$laser laryngeal microsurgery were reviewed for the safety of $CO_2$laser in laryngeal microsurgery. Vocal polyp (46,3%) was the most common pathology in our cases. The others were vocal nodule, Reinke`s edema, epiglottic cyst, laryngeal granuloma, laryngeal papilloma, intracordal cysts, laryngeal tuberculosis, laryngeal web, laryngotracheal stenosis, and laryngeal cancer. Following complete equipment controls, treatment area controls, maintenance, service and procedural controls, personel protective equipment, and warning signs, no complications were found in our cases. In conclusion, laryngeal microsurgery with $CO_2$laser could be done safely without complication if complete preoperative preparation and education of medical staff preceded.

• Proceedings of the KIEE Conference
• /
• 1987.11a
• /
• pp.408-411
• /
• 1987

We have designed the power supply of an 120W $CO_2$ Laser for non-metal material processings. High voltage is automatically controlled by means of thyristor triggered phase control. Pulse and C.W. mode are selectively generated by means of discharge current control. It is possible to interface this system with other Numerical Controller. Also, safety interlock circuit is incorporated in this system.

• Journal of Oral Medicine and Pain
• /
• v.35 no.2
• /
• pp.119-122
• /
• 2010

Carbondioxide($CO_2$) laser is one of the most widely employed lasers in oral soft tissue surgery because of its excellent affinity for water based soft tissues. It has some inherent advantages such as hemostasis, less postoperative swelling, reduction of bacterial population at surgical site, less need for suturing, less scarring, and less postoperative pain compared to conventional surgical therapies including the use of scalpel, diathermy, cryotherapy and electrosurgery. A 30-years-old male was presented with gingival swelling. Clinical examination revealed a well?defined pedunculated fibrotic mass on the buccal gingiva near right maxillary 1st molar. In radiographic examination, no remarkable abnormality was seen. Excisional biopsy was performed with $CO_2$ laser (continuous wave mode, 4.0W). Histological diagnosis was "Irritation fibroma". $CO_2$ laser has advantages those are suitable for surgical treatment of intraoral lesion. If appropriate training and experience are provided, the dentist would be able to manage intraoral lesions more efficiently and successfully with the use of the $CO_2$ laser.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.25 no.4
• /
• pp.761-771
• /
• 1998

In this study, attempt has been made to evaluate the effect of $CO_2$ laser irradiation on enamel surface structure and the bond strength of sealant material. Conventional acid etching was used as a control technic for comparison. The results obtained from this experiment were as follows; 1. The highest mean shear bond strength value was observed in samples of Group I (acid-etching) with the statistical significance(p<.05) between all the other groups. 2. The shear bond strength in Group IV was the lowest among laser etching groups. but there were no significant difference between them(p>.05). 3. Scanning electron microscopic observation showed that the rough and irregular surface was created by $CO_2$ laser treatment with the formation of numerous pores, micro-cracks, and small bubble-like inclusion. Increasing the energy density induced localized surface melt with a thin smooth glaze-like appearance. 4. In acid-etched control specimen cohesive failure predominated, whereas adhesive failure was the main mode in laser-treated group. Based upon the above-mentioned results, it can be assumed that the $CO_2$ laser is not an adequate substitute for the acid-etch technique in enamel preconditioning. More studies are required to explore the effective condition of laser irradiation which could attain the better bond strength of restorative materials.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.24 no.1
• /
• pp.27-40
• /
• 1997

This study investigated the effects of laser irradiation on the exposed pulp and the possibility of direct pulp capping with the $CO_2$ laser. Results were obtained from the observation of the residual pulpal healing process. Class V cavities on 48 anterior teeth from 8 adult dogs were prepared and pulp chambers were intentionally opened with dental explorer. The control group consisted of 16 teeth. $Dycal^{(R)}$(Caulk Co., U.S.A.) was applied to exposed site once bleeding was stopped. Cavities were sealed with $I.R.M^{(R)}$. In the experimental group 1 (16 teeth), laser(LASERSAT $CO_2^{(R)}$, Satelec Co.) was irradiated on the exposed pulp. The laser procedure followed the manufacturers recommendations for the treatment of human pulp(1.5 Watts, 0.2 seconds, unfocused), and cavities were sealed with $I.R.M^{(R)}$. In the experimental group 2 (16 teeth), laser was irradiated on the exposed pulp in a more powerful dosage(5.0 Watts, 0.2 seconds, unfocused), and cavities were sealed with $I.R.M^{(R)}$. Two dogs were sacrificed immediately after experiment and the others were sacrificed at intervals of one, three, and eight weeks respectively. All teeth were routinely processed and the pulpal tissues and odontoblastic layers were observed by the light microscope. The results were as follows; 1. In the control group, the initial mild inflammation had improved to normal by week eight. An active formation of reparative dentin was observed at week three, and at week eight, a firm dentin bridge was present beneath the $Dycal^{(R)}$ with no inflammatory responses in the remaining pulp. 2. In the experimental group 1, immediately following irradiation, the superficial shape of the exposed pulp was crater-like. And it was lined with the coagulated layer, $60{\sim}70{\mu}m$ in width. Moderate inflammatory pulpal conditions existing at week one were improved to mild at week eight. And from the week three specimens, a reparative dentin formation was observed in the adjacent odontoblastic layer of the exposed site. A dentin bridge at the exposed site, however, did not form during the experimental period. 3. In the experimental group 2, the width of the coagulation layer lining the crater was $70{\sim}130{\mu}m$. Beneath the coagulated layer, severe inflammatory pulpal responses were observed at week one, and conditions did not improve during the experimental period.