Ablative Lasers
Ablative lasers such as CO2 and Erbium Yag 2940nm are more invasive, but produce the best clinical results. They work by vaporizing the epidermis. This process causes the skin to heal and restructure and increases collagen production in the dermis by stimulating the fibroblast cells.
Ablative lasers are great for treating visible signs of aging and the results generally last for 1 to 5 years. They can also be used to treat acne scarring, pigmentation irregularities, congestion and unwanted lesions.
Ablative lasers present a longer recovery time and some patients require 1 to 2 weeks of recovery time, depending on intensity.
Non-Ablative Lasers
Non-ablative lasers such as erbium glass 1550nm are far less invasive than ablative treatments. They work by heating up the targeted dermal tissue, without ablating the epidermis. This process stimulates your body's collagen production to help skin imperfections such as fine lines or wrinkles.
Because they do not resurface the skin as invasively as ablative lasers, multiple treatment sessions will be necessary to achieve modest clinical results. However, patients benefit from almost no downtime.
Summary Essentially, the difference between ablative and non-ablative lasers is the depth of treatment. Ablative lasers strip away the top layer of skin, providing significant improvement in only 1 treatment (usually) and treat both layers of skin in a single pass. This comes at a cost of more downtime. Non-ablative lasers target the deeper layers of skin, involve less downtime, but require multiple treatments.