Collagen Biostimulators: Calcium Hydroxylapatite and PLLA
A physician workshop on collagen biostimulators: what CaHA and PLLA do in the tissue, dilution, safe planes, session planning and complication management.
This workshop was taught in Turkish. The summary and terms below are translated from that recording; the audio in the video is in its original language.
This is the full recording of a collagen biostimulator workshop Dr. Sinan Akyürek held for physicians on 3 June 2026. The two molecules on the table are calcium hydroxylapatite (CaHA) and poly-L-lactic acid (PLLA): what each one does in the tissue, where it can go and where it cannot, how much it is diluted for which region, and how the plan is explained to the patient. The workshop was taught in Turkish; the summary and the glossary on this page are translated from that recording.
The first half is theory and case work: the microsphere structure of CaHA and how fibroblasts wrap around it, why a product that cannot be dissolved changes the way you think about complications, a patient who came back with an abscess nine months after injection, why particle-based products are kept out of the mobile central face, and PLLA’s history of reconstitution and granulomas from 1999 to today. The second half is hands-on on two models: zygoma, temple, masseter and mandibular angle, entry through the modiolus, aspiration at every point, and the millilitres actually planned for each region.
It is meant for physicians who already inject and want to follow another practitioner’s reasoning, including where he stops: the point at which collagen gain alone will not lift a descended malar fat pad, and what he tells the patient at that point. This is educational content for physicians, not medical advice; no treatment plan can be taken from a recording without an examination.
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What the video covers
- 0:01 What is calcium hydroxylapatite, and how does the body respond to it?
- 5:26 How do you manage a complication with a product that cannot be dissolved?
- 10:37 The product evolved, but patient history still decides
- 15:58 An abscess nine months later: how was the case managed?
- 21:16 Ratio, dilution and skin type in the hybrid product
- 26:20 Why does a biostimulator not go into the central face?
- 31:37 Does marketing set the number of sessions, or the patient?
- 36:45 Nose and temple: the risky regions for calcium
- 41:47 Why is PLLA easier in a ready-filled syringe?
- 47:15 Massage, photographs and the change the patient cannot see
- 52:58 Where does a collagen biostimulator's limit end?
- 58:16 Planning on the model: jawline or zygoma?
- 1:03:30 Which losses can be read on the model's face?
- 1:08:56 Brow filling, aspiration, and how is the bleeding stopped?
- 1:14:35 How many millilitres are planned for which region?
- 1:19:51 Entering through the modiolus: how many points can you reach at once?
- 1:25:18 How was the seven-point technique modified?
- 1:30:35 Lip, alar base and nasolabial fold through a single entry
- 1:36:32 How much product was used in total?
- 1:41:36 Both sides finished: closing and a product comparison
Terms in this workshop
- PLA
- Poly-L-lactic acid. In the recording it is described as the biostimulator that came into use with Sculptra in 1999, stimulates collagen production and is preferred for deep tissue and soft tissue support.
- malar
- The cheekbone region. In the recording, the malar fat pad dropping once it loses the support it took from the zygoma is shown as the first place where midface volume loss can be read.
- collagen
- The structure biostimulators increase in the tissue. In the recording, collagen gain is said to give tightening and some lifting, but not to cover heavy volume loss on its own.
- temporal
- The temple region. In the recording, volume loss here pulls the midface down, and because the skin is thin the product has to be diluted for subdermal application.
- cannula
- A blunt-tipped injection instrument. In the recording, working with a 22-25 gauge, 50-70 millimetre cannula is called the most reliable route for these products.
- oedema
- Swelling that develops in the tissue after injection. In the recording, biostimulators cause a mild irritation in the tissue and the oedema that follows will certainly be seen; it is managed with cold application and, where needed, systemic treatment.
- hyaluronic acid
- In the recording it appears as the component that gives immediate volume and, because it can be dissolved with hyaluronidase, leaves a way back in complication management; in the product combined with calcium hydroxylapatite it is what provides that way back.
- elastin
- In the recording it comes up through the collagen-elastin balance in the skin: skin high in elastin and low in collagen stretches like chewing gum when it is pulled, and responds well to collagen gain.
- Liquid Facelift (Sıvı Yüz Germe)
- In the recording it appears as a trend that has spread on social media; the doctor explains that it does not come out of a single product but out of filler and biostimulator used together, and that collagen gain stays limited on its own.
- fibroblast
- In the recording, the cells that surround calcium hydroxylapatite crystals by putting out foot-like processes and start collagen production.
- SMAS
- In the recording, while the layers of the face are being listed, it appears as the layer above the muscles and beneath the superficial fat pad.