Effect of low-level laser treatment after installation of dental titanium implant-immunohistochemical study of RANKL, RANK, OPG: an experimental study in rats.
OBJECTIVE
This experiment using an animal experimental model was conducted in order to investigate the effect of low-level laser therapy (LLLT) on the healing of the dental titanium implant.


METHODS
The experimental group received LLLT for a week and the control group did not. Each group consisted of 10 rats. Two rats from the groups were euthenized on the days 1, 3, 7, 14, and 21 of the experiment. The expression of receptor activator of nuclear factor kB ligand (RANKL), osteoprotegerin (OPG), and receptor activator of nuclear factor kB (RANK) were investigated.


RESULTS
The expression of RANKL was observed from the initial stage of the installation of the implant for both the experimental and control groups. However, the degree of expression was higher in the experimental group. The degree of expression of OPG increased remarkably in the experimental group, while in the control group the degree of expression increased only slightly. In the experimental group, the expression of RANK was observed from the first day, but in the control group, it was weakly observed after day 3. The overall expression within the bone was slight on day 7 in the control group, while an active expression was observed in the experimental group. Bone density after installation of dental titanium implant during osseointegration in the experimental group was higher than the control group. The surface and structure of the titanium implant was not damaged by low-level laser (LLL).


CONCLUSIONS
From the above results, the expression of OPG, RANKL, and RANK during the osseointegration of the dental titanium implant was observed within bone tissue. The application of the LLL influenced the expression of OPG, RANKL, and RANK, and resulted in the expansion of metabolic bone activity and increased the activity of bone tissue cells.
Kim
Yong-Deok
YD
Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan National University, Busan, Korea.
Kim
Sung-Sik
SS
Hwang
Dae-Seok
DS
Kim
Sung-Gil
SG
Kwon
Yong-Hoon
YH
Shin
Sang-Hun
SH
Kim
Uk-Kyu
UK
Kim
Jong-Ryoul
JR
Chung
In-Kyo
IK
D000818:Animals; D015519:Bone Density; D003757:Dental Implantation; D015921:Dental Implants; D007150:Immunohistochemistry; D028022:Low-Level Light Therapy; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D016348:Osseointegration; D053244:Osteoprotegerin / Q000378:metabolism*; D053245:RANK Ligand / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013977:Tibia / Q000378:metabolism / Q000601:surgery; D014025:Titanium
D015921:Dental Implants; D053244:Osteoprotegerin; D053245:RANK Ligand; D014025:Titanium