The 2026 randomized trial tested calcium hydroxylapatite with CO2 ablative fractional laser in 160 people with atrophic acne scars. For people with boxcar scars — flat-based pits with sharp walls — it means filler-plus-laser is a clinic option to discuss with a dermatologist.
Springer reports the study ran at a Deyi/Dexi clinic from December 2023 to March 2025 trial report. It assigned patients to observation group A or control group B. The trial studied medical treatment, not home care.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Official resources:
- Read the official guidance from NIH — Use this primary source to verify the official guidance.
- Read the official guidance from NIH — Use this primary source to verify the official guidance.
Table of Contents
- What did the 160-person trial test?
- Is your scar actually boxcar?
- Why pair filler with laser for these pits?
- What limits and side effects matter most?
- What should you ask your dermatologist?
What did the 160-person trial test?
The study enrolled 160 people with atrophic acne scars. Group A received observation for calcium hydroxylapatite plus CO2 laser, and group B served as control.
Care took place in one aesthetic clinic. That setup keeps methods steady but narrows who the findings fit.
Is your scar actually boxcar?
A 2024 NIH review describes boxcar scars as round-to-oval depressions with sharp vertical walls and a flat base that can reach the dermis scar review. Icepick scars look narrow and V-shaped. Rolling scars slope widely and look wave-like.
Use shape to sort scars before seeking care: Shape guides treatment because depth and edge respond differently. Do not judge from one mirror angle. Check scars in side light and front light.
- Boxcar: wide pit, sharp edge, flat bottom
- Icepick: narrow pit, steep V, small opening
- Rolling: broad dip, sloping edge, uneven surface
Why pair filler with laser for these pits?
A Taylor & Francis review reports earlier open trials of calcium hydroxylapatite improved boxcar scars but not in icepick scars earlier trials. The authors suggested pairing it with subcision or resurfacing for mixed scars.
The pairing targets both surface texture and depressed volume. That logic fits mixed scarring better than one method alone.
What limits and side effects matter most?
A 2026 Wiley review cautions that the 160-person trial was prospective but single-center, which limits general use laser safety review. CO2 ablative fractional laser also brings prolonged downtime.
Pigment darkening risk runs higher in Fitzpatrick types III-VI. Plan for visible healing time and sun protection. Ask how the clinic handles pigment risk for your skin tone.
What should you ask your dermatologist?
Adults with boxcar-type scars are the relevant group to raise this combination. Bring your scar history, pigment history, and healing concerns. Ask these direct questions: Book the consult before any event with photos, and ask for written aftercare to follow at home.
- Confirm my scar mix: boxcar, icepick, rolling, or mixed?
- Am I prone to dark marks after acne or procedures?
- How many days of redness and cover-up should I plan for?
- What sun protection and follow-up visits do you require?
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