CaHA vs crosslinked HA filler
This page places verifiable specifications side by side. It does not rank materials, score them, or recommend one over another.
Comparison
What is the difference between CaHA and hyaluronic acid filler?
These two materials fall into the same regulatory cell. They travel the same pathway in Korea and the European Union, and in the United States their premarket approvals carry the identical generic name, 'implant, dermal, for aesthetic use'. The mechanisms described in the literature are not the same: one is a ceramic particle that provokes a host response, the other a polysaccharide gel that supplies matrix directly. Rheological values measured side by side under identical conditions differ by more than an order of magnitude.
| Aspect | CaHA (calcium hydroxylapatite) | Crosslinked HA (hyaluronic acid filler) | Basis |
|---|---|---|---|
| Family | Stimulatory material — ceramic microsphere | ECM constituent — crosslinked polysaccharide | — |
| Chemical formula | Ca10(PO4)6(OH)2 | (C14H21NO11)n | — |
| Mechanism as described in the literature | Particles are described as acting as a scaffold, followed by fibroblast response and matrix deposition | Supplies matrix rather than provoking the host to make it; crosslinking slows enzymatic degradation | — |
| Storage modulus measured under identical conditions (1 Hz, 37 °C) | Mean 1122.1 Pa (SD 67.1) | Mean 63.9 Pa (SD 3.0) | Legal text |
| Complex viscosity measured under identical conditions (1 Hz, 37 °C) | Mean 207.2 Pa·s (SD 11.6) | Mean 10.9 Pa·s (SD 0.5) | Legal text |
| Means of degradation or removal | No corresponding agent is recorded in this reference | Reviews record that the gel is degradable with hyaluronidase | — |
| Regulatory identity — Korea and European Union | Medical device in both. Biomaterial for tissue restoration in Korea; MDR Annex XVI point 3 in the European Union | Identical — the same provisions apply | Legal text |
| Regulatory identity — United States | Premarket approval PMA P050037, earliest approval found December 2006 | Premarket approval PMA P020023, earliest approval found December 2003 | Legal text |
| Highest-tier evidence cited on this site | Systematic review of mechanisms related to skin regeneration (PMID 37332763) | Rheology review and in vitro characterisation studies (PMID 38677707, 30921116) | — |
The regulation does not separate them
This is an unusual case in the atlas: the regulatory identity of the two materials matches across all three markets where it could be established. They receive the same classification in Korea, fall under the same provision in the European Union, and in the United States their premarket approvals even carry the same generic name.
The described mechanisms do not match. One is a ceramic particle placed so that host tissue responds to it; the other is a gel made by crosslinking a component already present in the dermal extracellular matrix. That fact says something about how to read the regulatory column. A classification does not tell you a mechanism. It records the route by which a product entered the market, not what happens in tissue.
The measurements came off the same instrument
One study measured both materials side by side on the same rheometer, in the same geometry, at the same temperature (37 °C) and the same frequency. Storage modulus differed by more than an order of magnitude.
Two things have to be held at once here. The first is that these values are comparable because they were produced under identical conditions. The second is that the study used four samples per class. Hyaluronic acid fillers differ substantially in crosslinking between products, and the literature describes that range as wide. So these numbers are the values of the materials that study measured, not the values of crosslinked hyaluronic acid.
Reversibility is where the practical difference sits
Reviews record that crosslinked hyaluronic acid is degradable with hyaluronidase. For the ceramic particle, this reference records no corresponding agent. Before duration or feel enters the discussion, that single property makes the risk calculation different in kind. It is also the item most often left out when the two are placed on one axis.
What is not on this page
No study observing both materials on the same clinical outcome measure was found. The comparison above is limited to material properties and regulatory identity; it is not a comparison of clinical outcomes.
Limitations & open questions
The rheological values above come from a single study measuring four samples per material class, and they describe the materials that study used rather than the class as a whole. Hyaluronic acid fillers vary in crosslinking degree and chemistry between products, and the literature describes a wide range of storage modulus values across them, so the figures here should not be read as values for crosslinked hyaluronic acid in general. These are also rheometer measurements, and one review cited in this reference states plainly that data linking such metrics to clinical outcomes is limited. No clinical study observing both materials on the same outcome measure was found in the searches behind this page.