Premium
Low level 809‐nm diode laser‐induced in vitro stimulation of the proliferation of human gingival fibroblasts
Author(s) -
Kreisler Matthias,
Christoffers Ann B.,
AlHaj Haitham,
Willershausen Brita,
d'Hoedt Bernd
Publication year - 2002
Publication title -
lasers in surgery and medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 112
eISSN - 1096-9101
pISSN - 0196-8092
DOI - 10.1002/lsm.10060
Subject(s) - irradiation , connective tissue , stimulation , laser , in vitro , chemistry , andrology , cell growth , incubation , materials science , pathology , medicine , endocrinology , optics , biochemistry , physics , nuclear physics
Abstract Background and Objective The authors investigated the effects of low level laser irradiation on the proliferation rate of human gingival fibroblasts (HGF) in vitro. Study Design/Materials and Methods HGF were obtained from gingival connective tissue explants and cultured under standard conditions. 110 cell cultures in their logarithmic growth phase were spread on 96‐well tissue culture plates and were irradiated at energy fluences of 1.96–7.84 J/cm 2 . Another 110 cultures served as control. An 809‐nm semiconductor laser operated at a power output of 10 mW in the cw‐mode was used. The time of exposure varied between 75 and 300 seconds. Laser treatment was performed alternatively once, twice, and three times at a 24‐hour interval. After lasing, incubation was continued for 24 hours. The proliferation rate was determined by means of fluorescence activity of a redox indicator added to the cell culture. Proliferation was determined 24, 48, and 72 hours after irradiation and expressed in relative fluorescence units (RFU). Results The irradiated cells revealed a considerably higher proliferation activity. The differences were highly significant 24 hour after irradiation (Mann‐Whitney U‐test, P < 0.05) but decreased in an energy‐dependent manner after 48 and 72 hour after irradiation. Conclusions A cellular effect of the soft laser irradiation on HGF is evident. Its duration, however, seems to be limited. These findings might be clinically relevant, indicating that repeated treatments are necessary to achieve a positive laser effect in clinical applications. Lasers Surg. Med. 30:365–369, 2002. © 2002 Wiley‐Liss, Inc.