Atrophic acne scars—classified structurally as ice-pick, boxcar, and rolling scars—present localized areas of dense, fibrotic collagen bands pulling down the epidermal topography. Resolving these depressions requires mechanical subcision via localized, deep microneedling parameters capable of breaking these restrictive fibrotic anchor networks.
For rolling and boxcar scars, the clinical protocol dictates a needle penetration depth of 1.0mm to 1.5mm, targeting the reticular dermis to trigger an intense neocollagenesis cascade.
Because scar tissue possesses higher physical density and resistance than normal dermal tissue, standard budget cartridges will deflect or dull rapidly during the procedure. Needle tip dulling mid-treatment increases the puncture force threshold, causing uneven treatment depths and excessive patient discomfort. For predictable scar revision, the structural alloy matrix of the needles must possess a high Vickers hardness rating, ensuring every puncture remains clean and uniform from the first pass to the final zone.