Kyushu University Academic Staff Educational and Research Activities Database
List of Presentations
Yoshito Yoshimine Last modified date:2019.06.27

Associate Professor / Division of Oral Rehabilitation / Department of Dental Science / Faculty of Dental Science

1. Tomato Kihara, Himeka Matsumoto, Yoshito Yoshimine, Evaluation of cleaning efficacy of laser-activated irrigation in a simulated accessory canal
, 第15回国際レーザー歯学会, 2016.07, Purpose: Laser-activated irrigation (LAI) using an Er:YAG laser (Erwin AdvErl: Morita, Japan) is an irrigant agitation method. However, the ability of LAI to efficiently clean accessory canals remains unclear. This study aimed to investigate the influence of pulse energy on the cleaning efficacy of LAI in the accessory canal.
Materials and Methods:
Transparent root canal models with an accessory canal were made from acrylic resin. A 0.2-mm diameter accessory canal was made horizontally in the apical area. Accessory canals were then filled with stained biofilm-mimicking gelatin gel. A solution of 5% NaOCl was used as an irrigant. We used an Er:YAG laser, irradiated at pulse energies of 30 mJ at 20 pps, in combination with a 200um diameter cone-shaped tip, placed 10 mm from the apex, for 20 s and 40 s, respectively. Conventional syringe irrigation with a flat-end needle was used as a control.
Digital photographs were taken and subsequently analyzed to determine the distance from the accessory canal entrance to the closest gelatin-irrigant interface. Differences within each irrigation group were quantified using a Tukey-Kramer test, with p values of <0.05 considered significant.
LAI resulted in a greater depth of hydrogel removal from the artificially created accessory canal than syringe irrigation. Laser irradiation at 30 mJ for 40 s, eliminated a significant amount of hydrogel compared to that achieved at 30 mJ for 20 s (P<0.05).
Conclusions: LAI enhanced the cleaning effect of NaOCl in the accessory canal in comparison to the effect achieved with syringe irrigation.
2. 佐藤浩美, 吉嶺 嘉人, 松本 妃可, Yasuharu GOTO, 赤峰 昭文, Evaluation of smear layer removal of root canals irrigated with different irrigation solutions and Er:YAG laser., 第9回世界歯内療法会議・第34回日本歯内療法学会学術大会o第11回日韓合同歯内療法学会学術大会, 2013.05, The aim of this study was to evaluate in vitro the cleaning ability of an Er:YAG laser system (2,940 nm)
equipped with a cone-shaped tip of 280 μm outer-diameter by scanning electron microscopy (SEM).
Single-rooted extracted human teeth were prepared with rotary Ni-Ti files. The mechanically
instrumented teeth were randomly divided into five groups. Each group was irradiated with an Er:YAG
laser for 30 s at 30 mJ and 20 pps, without air or water spray. The tip was placed 10 mm from the apex.
Different solutions were used: group 1 laser irradiation in distilled water as a control. group 2, laser
irradiation in NaOCl; group 3, laser irradiation in EDTA; group 4, laser irradiation in NaOCl following
EDTA, and group 5, laser irradiation in EDTA following NaOCl. The samples were subsequently split
longitudinally into 2 halves, and the canal walls were examined with SEM. The smear layer was more
effectively removed in groups 4 and 5 compared to groups 1, 2, and 3. In groups 4 and 5, the smear layer
was removed in whole areas of the canal wall. However, Group 5 showed marked erosion in the periphery
of dentinal tubules. These results suggest that the use of EDTA following NaOCl might be useful in the
Er:YAG laser irrigation of the root canal..
3. 松本 妃可, 吉嶺 嘉人, 新井裕基, isamu hashiguchi, 赤峰 昭文, The effects of Er:YAG laser on cleaning accessory canals in vitro., 第9回世界歯内療法会議・第34回日本歯内療法学会学術大会•第11回日韓合同歯内療法学会学術大会, 2013.05, The aim of this study was to evaluate the efficiency of laser-activated irrigation (LAI) in cleaning
accessory root canals. Simulated root canal models with accessory canals were used. Accessory canals of
0.2-0.3 mm in diameter were located at 2 and 7 mm from the apex of the main canal (#40). An Er:YAG
laser was equipped with a novel cone-shaped tip (outer diameter: 280 μm), having a lateral emission rate
of approximately 80%. Laser light was emitted at a pulse energy of 30 mJ (output energy: 11 mJ), without
air or water spray. Fluid flow dynamics were observed using fluorescent micro-tracers under a high-speed
camera. Moreover, laser-induced bubble patterns were visualized in accessory canals. In high-speed
imaging of irrigant flow, tracers revealed quick motion of the fluid both in the main canal and accessory
canals. Secondary cavitation bubbles were clearly observed in the narrow accessory canal space.
Furthermore, cavitation bubbles were created much more frequently in the accessory canals than in the
main canal. These results suggest that LAI irrigation using Er:YAG laser equipped with a cone-shaped
tip may be promising in cleaning accessory root canals..
4. 吉嶺 嘉人, 松本 妃可, 新井裕基, 赤峰 昭文, Removal of broken instruments using the intra-canal endoscope equipped with Er:YAG laser., 第9回世界歯内療法会議・第34回日本歯内療法学会学術大会o第11回日韓合同歯内療法学会学術大会, 2013.05, A new device which can visualize a target in the root canal and ablate the target by Er:YAG laser
irradiation has been developed. This system allows not only to identify canal aberrations such as a crack
and accessory canal, but to eliminate unnecessary obstacles including gutta-percha and broken
instruments in the root canal. The device is composed of a camera channel, laser-fiber channel, water
channel, and several illuminating fibers. The quartz-fiber laser tip of 80 or 90 mm in length can be
inserted via the laser-fiber channel. The identical alignment of the endoscope and laser fiber makes it
easier to aim at a target accurately. Additionally, because the endoscopic vision is maintained even when
water is filled in a root canal, the laser irradiation can be performed under water cooling, making the
ablation procedure safer in the root canal. For example, foreign materials like a broken file can be
eliminated carefully not to damage the surrounding normal tooth structures. Dentin surrounding the
broken instrument is laser-ablated under endoscopic observation, resulting in loosening of it. Afterward,
an ultrasonic device is used to retrieve the fractured instrument. In conclusion, the intra-canal endoscope
in combination with an Er:YAG laser might be useful for endodontic troubles because it allows not only
preoperative diagnosis or observation, but also the visible treatment in an elimination of obstructions in
the root canal..
5. The Combined Effects of an Er:YAG Laser and Oxalate-based Desensitizer on the Occlusion of Exposed Dentinal Tubules in Vitro
6. Micro-computed tomography evaluation of laser-activated irrigation in a simulated root canal .
7. Visualization of irrigant flow and cavitation induced by Er:YAG laser within a root canal model.
8. Root canal irrigation using Er:YAG laser.
9. Removal of an intra-canal foreign body using Er:YAG laser.
10. Evaluation of intra-canal moisture using the modified electric apex locator.
11. Cavitation effects of the pulsed laser in root canal models.
12. Intracanal bactericidal effects of Er:YAG laser.
13. Antibacterial properties of experimental glass-ionomer sealer combined with chlorhexidine.