Introduction to Lasers

FACIAL AESTHETICS

Tracey Bell presents an introduction to lasers and light therapy Anyone who knows me will tell you that I entered this arena with my eyes wide open and with a quest for knowledge. I had a medical and dental background, a building block for the field of aesthetic medicine, but did lasers (light amplification by stimulated emission of radiation) enter into my head?

Initially no, never, but what I have witnessed first hand is that lasers are fast becoming the ‘new kids on the block’, producing life changing results for patients and clinicians alike. Lasers certainly need to be on the menu for those clinicians who want to be ahead of the game.

Education is key and knowledge is power. My message to all of you is this: don’t be left in the dark, let there be light!

A buyer’s guide to lasers and light systems Unlike man, not all light systems are created equal!

Therefore, it is critical to understand their explicit sciences when researching specific products. First and foremost, all technologies have their niche applications and specialties but in most cases their overall differences are negligible. Nevertheless, having an accurate understanding of their variations can help you secure a unit destined to deliver desirable results, meeting both patient and practice demands yet not breaking the proverbial bank.

It’s all in the family – the diverse laser mediums The tell-tale technology details of the different types of lasers, complete with their various wavelengths, are diverse. The laser medium can be a solid, a gas, a liquid or a semiconductor, with lasers commonly designated by the type of ‘lasing’ material employed.

24 | Irish Dentist | May 2009

Let there be light

Solid-state These lasers have lasing material distributed in a solid matrix of crystal, examples of such being the ruby or eodymium:yttrium-aluminum garnet (aka YAG lasers). The neodymium:YAG laser emits infrared light at 1,064 nanometres (nm).

The ruby laser is primarily known for tattoo removal procedures. It consists of a flash tube (like you would have on a camera), a ruby rod and two mirrors (one half-silvered).

The ruby rod is the ‘lasing medium’ and the flash tube pumps it. The ruby laser works by producing short pulses of intense light that pass harmlessly through the top layers of the skin to be selectively absorbed by the tattoo pigment. This laser energy causes the tattoo pigment to fragment into smaller particles that are then removed by the body's immune system. The laser selectively targets the pigment of the tattoo without damaging the surrounding skin.

The Alexandrite (crystal) laser produces reddish light just at the limit of visibility, at

755nm, and is suitable for rapid hair removal treatments in patients with light to olive complexions.

Gas lasers The carbon dioxide laser (CO2 laser) was one of the earliest lasers to be developed (invented by Kumar Patel of Bell Labs in 1964) and is still one of the most useful.

Carbon dioxide lasers are the highest power continuous wave lasers currently available.

The CO2 laser produces a beam of infrared light with the principal wavelength bands centring around 9.4 and 10.6 micrometres.

Today the CO2 laser has been given a ‘make-over’ with its state-of-the-art ‘fractional’ twist.

This application drills a micro beam matrix-style spot size to the target area, leaving voids of healthy tissue intact to facilitate healing while capitalising on the thermal energy and resurfacing benefits. This new generation technology penetrates about 100 microns deep to activate collagen remodelling at the dermal/epidermal juncture and is indicated for deep acne scarring and wrinkles.

Semi-conductor lasers Sometimes called diode lasers, this type of laser is not solidstate. These electronic devices are generally very small, use low power and could be used for hair removal or on LED devices.

Their main claim to fame Nothing is better for hair removal than lasers! Several wavelengths of laser energy have been used for this procedure, from visible light to near-infrared radiation. These lasers are usually defined by the lasing medium used to create the wavelength (measured in nanometres (nm)). Fluence or energy level, measured in joules per square centimetre (J/cm2), is an important consideration as well as laser wavelengths, with longer wavelengths safer for darker skin types due to less melanin absorption: • Ruby: 694nm, suggested for skin types I to III • Alexandrite: 755nm, the ‘gold standard’ for skin types I to IV • Pulsed diode array: 810nm, the ‘gold standard’ for skin types II to V www.IrishDentist.ie

• Nd:YAG: 1064nm, suggested for skin types IV to VI. However, less absorption translates into an efficacy trade-off, thus epidermal cooling allows for higher fluences while reducing pain and potential side effects, with darker skin types at the greatest risk.

Four types of cooling have been developed, which are: 1. Clear gel – usually chilled (messy) 2. Contact cooling: through a window cooled by circulating water (expensive) 3.Cryogen spray: immediately before/after the laser pulse (expensive) 4. Air cooling: forced cold air at -34ºC (Zimmer Cryo-5 unit), an excellent cooling mechanism but expensive at several thousand euros.

The primary principle behind laser hair removal is selective photothermolysis.

Lasers cause localised damage by selectively heating dark target matter in the area that causes hair growth while not heating the rest of the skin.

The foremost chromophore for laser hair removal is eumelanin (the specific melanin that gives brown or black hair its colour).

Since lasers that are intended for topical use can only penetrate skin tissue a few millimetres deep and there are multiple active growth hair cycles within the body, legally practitioners arrive at the expression permanent hair reduction as opposed to permanent hair removal.

The spot size of the laser beam also affects its treatment, theoretically with the width of the ideal beam about four times as wide as the target is deep. Most lasers have a round spot about the size of your little finger (8-10mm).

The downside of lasers for hair removal is that they could compromise the comfort level of the patient and they are expensive. The top of the range system features the best that money can buy, encompassing a customisable ‘platform’ unit complete with multiple technologies. Diode and YAG lasers, as well as IPL (intense www.IrishDentist.ie

pulsed light) and radio frequency, are housed together with an exclusive upfront pricing plan for a whopping €150,000 if ‘fully loaded’, with new technology upgrades running from €20,000 to €40,000.

Laser tattoo removal Almost any tattoo can now be removed with the use of lasers.

The treatment works by breaking down the particles of ink suspended beneath the skin, enabling your immune system to eliminate them naturally. Several types of lasers and wavelengths are employed to remove different colour groups and the specific laser pulses are directed onto the tattoo, breaking up the pigment. Over the next several weeks the body’s macrophages remove the treated pigmented areas. Generally, from three and up to 12 monthly sessions may be required and treatment times vary according to the size of the tattoo, which can take anywhere between 15 and 45 minutes.

Figure 1: Wavelengths of different types of laser

Figure 2: Apsorbtion rate according to wavelength in nanometres

Non-ablative, ablative and fractional rejuvenation The new generation of laser resurfacing technologies removes the upper layers of skin via target tissue vaporisation while harnessing photodynamic energy to smooth out fine lines and wrinkles, revise scars or to treat irregular skin pigmentation.

The most conventional are either non-ablative (mild) or ablative (deep) applications within the Erbium YAG family of lasers that is a 2940 wavelength on the infrared or invisible side of the light spectrum. My approved arsenals of lasers include the Whisper Extended Ablation Laser Peel, the Harmony Erbium YAG Laser and the Pixel.

The Whisper Peel technology is specifically indicated for pitted acne and keloid scarring, lines and wrinkles, mild hyper pigmentation, and collagen remodelling for natural skin

Figures 3 to 6: Before and after intense pulsed light (IPL) treatment May 2009 | Irish Dentist | 25

FACIAL AESTHETICS

rejuvenation. It is equivalent to 12 micro-dermabrasions per treatment delivered with micro precision and control for superior results. It requires three to five sessions over a three- to five-month period for optimum results but can also be used as an in-between time beauty boost. The patient can expect anywhere from three to five days of downtime for an intensive ‘arctic’ peel or no downtime for a lunchtime express rejuvenating ‘LitePeel’.

Full facial treatments or local region sessions can be accomplished with no discomfort.

You can, however, dare to go deeper with the ‘rapid results’ Harmony Erbium YAG laser. The Harmony is indicated for the same conditions on more severe cases. The treatments can take between 30 minutes to an hour and the recovery time is five to 10 days.

Pixel Photo Rejuvenation is a safe and effective treatment for fractional ablative skin resurfacing on the face, neck, chest, arms and hands. It is designed to treat aged and photo-damaged skin, and to improve the quality, appearance and texture of the complexion while it stimulates collagen regeneration. The skin around the treatment area feels firmer and tighter with a smoother surface texture. It is premised on micro beam technology and is intended as a gradual process protocol that happens over several treatments.

Approximately three to five treatments are recommended at bi-weekly intervals and take around 45 minutes with no recovery time.

Alternative solutions: powerful and profitable Intense pulsed light (IPL) devices are not lasers, because they emit broadband, noncoherent light of many different wavelengths from a xenon flash lamp (an electric glow discharge lamp designed to produce extremely intense, incoherent, full-spectrum white light for very short 26 | Irish Dentist | May 2009

Table 1: Laser applications • Hair removal • Tattoo removal • Skin resurfacing • Peri-oral rejuvenation • Peri-orbital rejuvenation • Rosacea treatment Figures 7 and 8: Before and during treatment for tattoo removal

• Acne and large pore treatments durations) and focusing optics.

By using ‘filters’, the wavelengths of light emitted from these devices may be weighted toward the longer wavelengths (400-1200nm) for use in hair removal as well as other applications.

The large spot sizes and fast repetition rates make rapid treatment of large areas possible. However, because most of the light energy is in the shorter wavelengths, treatment of darker skin types is less effective and more risky than with the appropriate laser.

Second generation IPL applications may be indicated for rosacea, port wine stain and acne clearance treatments, micro/thread and varicose vein removal, skin tightening, hyperpigmentation, cellulite reduction therapy and more.

This new technology incorporates ‘dual mode filtering’ and other important advances that result in safer and more effective treatment than the older systems, which were initially designed for simple processes such as hair removal.

The focused, broad spectrum light is applied to the surface of the skin by way of either a hand-held wand or by an articulated arm. The intense light travels down the hair shafts, where it strikes the bulb, or root, of the hair. The bulb is usually where the highest concentration of melanin is located, as opposed to the rest of the hair shaft.

When the light strikes the

dark-coloured melanin, the light is converted to heat energy. The bulb and most of the hair shaft is instantly vaporised. The intense heat radiated by the hair also destroys the hair-producing papilla or the entire hair follicle. It is also claimed that direct light-heat conversion occurs directly in the darker coloured capillaries that bring nourishing blood to the follicle.

The pulses of light produced by IPL equipment are very short in duration, so discomfort and damage to non-target tissues is minor.

Most people who undergo IPL epilation only experience slight irritation similar to that of minor sunburn, although under certain circumstances blisters may occur. The light that emanates from the IPL wand is filtered to remove any ultraviolet (UV) components, eliminating the possibility of UV skin damage.

With IPL, external coolants are still recommended and although you won’t be digging quite as deep into your pockets, you will still need to reach for at least €50,000 to invest into a reasonably sound system if you want the pristine package.

A final note Combined with other treatments such as chemical peels, microdermabrasion, radiofrequency, fillers and Botulinum toxin, lasers are the new kids on the block.

• Photo damage • Fine lines and wrinkles • Skin tightening

To compare prices and product performance, visit www.miinews.com

Dr Tracey Bell is founder and CEO of TRACEY BELL. A cosmetic dentist and aesthetic physician, Dr Bell started her first dental practice, Craigend Dental, in the Isle of Man in 1995. Six years later she expanded into aesthetic medicine, launching The Kensington Clinic next door to her dental practice.

The first TRACEY BELL clinic, her ‘body shop for the 21st century’, was opened in Douglas, Isle of Man, in October 2006. Then, in June 2007, she launched a 7,000 sq ft medical spa in Liverpool, offering dental, non-surgical, laser, spa, hair, body shaping, SkinScription and mineral make-up treatments. Dr Bell is recognised by both the dental and aesthetic industry as a practitioner of international standing and is an inspirational speaker noted for her motivational and authoritative presentations. www.IrishDentist.ie