Page 93 - Chapter 3 - Fundamentals of Laser/IPL Hair Removal
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Chapter 3 – Fundamentals of Laser/IPL Hair Removal 1st Edition
‘slowed’ growth in 73% of cases compared with 64% with an IPL unit. He also found that post- inflammatory hyperpigmentation occurred following IPL treatments, but not with the YAG laser.
An excellent study by Tina Alster et.al. found that the Nd:YAG laser generated a 70-90% level of hair reduction with an Nd:YAG at 40 to 50J/cm2 over 3 treatment sessions, on twenty Fitz 4 to 6 females. These results were observed 12 months after the third session. They also found transient pigmentary changes on the skin which mostly resolved themselves.
Bouzari et.al. carried out a comparative study with alexandrite, diode and Nd:YAG lasers, on 75 patients. They found that the alexandrite and diode lasers appeared to perform better than the Nd:YAG, but we think that they didn’t use the most appropriate parameters for that laser.
Khoury et.al. also compared these lasers, individually and in combination mode. They found the best results with the alexandrite on its own, followed by the combined alexandrite/ YAG, the doped laser and then the Nd:YAG on its own. They state that there was no observable benefit of combining the alexandrite with the Nd:YAG over the alexandrite on its own. But, as with Bouzari above, this depends heavily on the chosen fluence and pulsewidths.
Seyyed et.al. also found that combining the alexandrite with an Nd:YAG laser was not beneficial, and, in fact, resulted in more adverse effects in the skin.
It appears from this very short review that all three laser types can be very successful in hair removal, when used correctly. Their results suggest that higher fluences are required, in line with our own theoretical calculations.
Diode Lasers – ‘SHR/in-motion’ vs ‘Stamping’ Techniques
We looked at two studies which compared the conventional ‘stamping’ technique with the newer ‘SHR’ or ‘in-motion’ technique.
Figure 33 – A typical diode laser head
A report from Braun compared these two techniques – both used 810nm diodes, one with a fluence range 5 to 10 J/cm2 at a repetition rate of 10Hz, with the other system delivering a fluence range of 25 to 40 J/cm2, in single shots at hair on legs.
The ‘single pass/high fluence’ approach generated a success level of 86% while the SHR approach resulted in a 91% success level. They concluded that this was NOT statistically significant meaning that there was very little difference between these results.
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