Comparative cell targeting in vitro using the CO2 laser

Abstract

In keeping with current interest in bactericidal effects of lasers to treat localized infection, we examined the effect of CO2 laser light on three bacterial species. Cell monolayers were placed atop filters minimizing the presence of extracellular water. Samples were exposed to irradiance values between 0 and 520 W/cm2 for 0.1 s. Cell survival was determined by colony counts. There was logarithmic killing of the bacteria with increasing irradiance; 90% kill was effected at 180 W/cm2 for Escherichia coli, 350 W/cm2 for Streptococcus mutans, and 250 W/cm2 for Bacillus stearothermophilus. However, standard deviations suggest no significant difference between cell types. Our results show the bactericidal effect of the CO2 laser with no remarkable difference between Gram types. However, substantial cell kill was achieved at relatively low irradiance. Whereas selectivity of damage may not be afforded by the CO2 laser, it may minimize collateral damage.

Evaluation of Patient Perceptions of Frenectomy: A Comparison of Nd:YAG Laser and Conventional Techniques

“…26 In a clinical study, White et al 8 used a pulsed Nd:YAG laser for periodontal surgery, and found that the laser produced less bleeding of periodontal tissues. However, there was no difference in inflammation compared with conventional surgery.…”

Postoperative discomfort after Nd:YAG laser and conventional frenectomy: comparison of both genders

“…Studies have reported that laser frenectomy induces coagulation and haemostasis of small blood vessels; in addition, there is less pain and bleeding, the wound is simultaneously sterilized, there is minimal damage to the surrounding tissue, there is wound contraction and the risk of postoperative infection is decreased. Many authors have also reported the absence of immediate postoperative pain after laser applications.…”

Effects of CO2 Laser Treatment on Fibroblast Attachment to Root Surfaces. A Scanning Electron Microscopy Analysis

“…Many authors have pointed out the bactericidal effect of the CO 2 laser and its application to detoxify root canal walls as well as cementum root surfaces. 17,18 Talebzadeh et al 19 examined CO 2 laser effects on different Gram-negative bacteria, at energy power levels lower than those used to cut and ablate dental hard tissues. These authors showed that the CO 2 laser demonstrated bactericidal action on all bacterial strains tested.…”