Bone regeneration (augmentation) is a surgical procedure aimed at rebuilding the volume of the alveolar ridge bone at the planned implant site. It is used when the quantity or quality of the patient's own bone is insufficient to accommodate an implant of appropriate length and diameter, ensuring long-term stability.
Why bone loss occurs after tooth extraction
The alveolar ridge bone serves as a support structure for tooth roots. When a tooth is lost, the bone at that site is no longer mechanically loaded and gradually undergoes resorption — atrophy. This process is inevitable and progresses throughout life: in the first year after extraction, up to 25–40% of bone width can be lost, and in subsequent years the atrophy continues, albeit at a slower pace.
With prolonged edentulism — several or even a dozen years — ridge atrophy can be so advanced that the bone base is insufficient for implant placement. It is precisely in such situations that prior bone regeneration is necessary, or alternative solutions such as zygomatic implants must be considered.
A dental implant restores mechanical loading to the bone and halts its atrophy — this is one of the key advantages of implants over removable dentures, which do not stop ridge resorption but actually accelerate it.
GBR — Guided Bone Regeneration
Guided Bone Regeneration (GBR) is the most widely used method of bone augmentation in implantology. It involves placing bone graft material at the defect site and separating it from the soft tissues with a collagen membrane. The membrane acts as a barrier: it prevents connective tissue and epithelium from growing into the area of regenerating bone, providing the time and space needed for new bone tissue to form.
Bone graft material — allogeneic bone from a tissue bank
In most situations, I use allogeneic bone from a certified tissue bank as the graft material. This is human bone obtained from a donor, subjected to rigorous processing, sterilization, and quality control. Its biological structure is similar to the patient's own bone, which promotes osteoconduction — the gradual ingrowth of the patient's own bone cells and biological remodeling of the graft material into living, native bone. Over months, the allogeneic material is replaced by the patient's own bone.
Allogeneic bone eliminates the need to harvest bone from the patient's body (as is the case with autogenous grafts), which reduces the number of surgical sites and shortens the procedure time.
Collagen membranes
Collagen membranes used in GBR are resorbable — they undergo biological degradation within several weeks to months, without the need for surgical removal. Their role is to protect the augmentation site during the early healing phase.
Platelet concentrates CGF and PRF
In selected cases, I use platelet concentrates — CGF (Concentrated Growth Factors) or PRF (Platelet-Rich Fibrin) — obtained from the patient's own blood during the procedure. They contain growth factors that stimulate tissue healing and angiogenesis. They serve as a supplement to the primary augmentation material, particularly in cases where healing is expected to be more challenging.
Bone grafts — bone blocks
For larger bone defects, particularly those requiring vertical augmentation (rebuilding bone height) or extensive horizontal augmentation, block bone grafts are used. A bone block — autogenous (harvested from the patient's body, e.g. from the chin area, mandibular ramus, or iliac crest) or allogeneic (from a tissue bank) — is secured to the native bone with titanium screws.
Autogenous grafts have the advantage of containing living bone cells, which promotes rapid integration — but they require a second surgical site for bone harvesting. Allogeneic grafts eliminate this necessity.
In most situations, we are able to avoid an additional donor site by using allogeneic bone from a tissue bank. This is a material with documented efficacy, a good safety profile, and one that minimizes the burden on the patient.
Vertical and horizontal augmentation
Horizontal augmentation involves rebuilding the width of the alveolar ridge — it is used when the bone is too narrow to properly place an implant without exposing its surface. It is typically performed using the GBR method.
Vertical augmentation is a technically more demanding and less predictable procedure than horizontal augmentation. It involves rebuilding the height of the ridge. Block bone grafts or specialized GBR techniques with non-resorbable (titanium) membrane support are typically used. The healing time is longer — 6 to 9 months.
| Type of augmentation | Scope | Method | Healing time before implantation |
|---|---|---|---|
| Small augmentation simultaneous with implantation | Minor defect at implant placement | GBR (allogeneic material + membrane) | No delay — heals together with the implant |
| Horizontal augmentation (GBR) | Narrow ridge | GBR | approx. 6 months |
| Block bone graft | Large bone defect | Bone block secured with screws | approx. 4 months |
| Closed sinus lift | Insufficient bone beneath the maxillary sinus | Access through the implant osteotomy | Simultaneous implantation (3–6 months osseointegration) |
| Open sinus lift | Significant bone loss beneath the sinus | Lateral access, window in the sinus wall | approx. 6 months |
When is bone regeneration needed?
The decision regarding the need for augmentation is made after analyzing a CBCT scan, which precisely shows the three-dimensional dimensions of the alveolar ridge. Augmentation is indicated when:
- the width of the alveolar ridge is too small to place an implant with an adequate safety margin (at least 1–1.5 mm of bone on each side of the implant)
- the bone height is insufficient to accommodate an implant of minimum length ensuring stability
- implantation is planned in the posterior maxilla, where the maxillary sinus limits the available bone from above (in which case a sinus lift is performed)
- during tooth extraction with simultaneous implantation, a bone defect requiring regeneration is found
Healing time
The time from the augmentation procedure to implant placement depends on the method and extent of bone reconstruction. Approximate timelines:
- block bone grafts — approx. 4 months
- sinus floor elevation (open and closed sinus lift) — approx. 6 months
- horizontal augmentation (GBR) — approx. 6 months
Many of these procedures can be performed simultaneously with implant placement — in such cases, the bone regenerates and the implant integrates with the bone at the same time, shortening the overall treatment duration. The decision for simultaneous implantation depends on the primary stability of the implant assessed intraoperatively.
After implant placement, the osseointegration phase follows, lasting another 3–6 months, after which the prosthetic restoration is delivered. For advanced bone defects requiring prior augmentation and delayed implantation, the total treatment time can range from 10 to 18 months.
Relation to sinus floor elevation
Sinus floor elevation (sinus lift) is a specific augmentation procedure concerning the posterior maxilla, where ridge atrophy is combined with expansion of the sinus cavity. It is a technically distinct procedure, discussed in detail on a separate page.
Sinus lift — procedure details
Alternative to augmentation for complete edentulism
In cases of complete maxillary edentulism with advanced bone loss, there is an alternative clinical pathway that avoids months-long augmentation procedures. Zygomatic and pterygoid implants anchor in bone structures beyond the atrophied alveolar ridge, enabling immediate prosthetic loading even with minimal ridge bone. This is a separate method — neither better nor worse than augmentation — selected individually depending on the clinical situation and the patient's expectations.
All-on-4 and All-on-6 — full-arch reconstructions
Zygomatic implants — bypassing bone loss
Frequently asked questions
Is bone augmentation painful?
The procedure is performed under local anesthesia and is not painful in itself. After the procedure, swelling and moderate discomfort may occur for a few days. We prescribe pain medications and antibiotics if needed. Most patients return to normal professional activities within 3–5 days of the procedure.
How long does healing take after bone augmentation?
Block bone grafts — approximately 4 months, sinus lift and horizontal augmentation — approximately 6 months. Many augmentation procedures can be performed simultaneously with implant placement, which shortens the overall treatment time. For advanced bone defects requiring delayed implantation — 10 to 18 months in total.
How much does bone augmentation cost?
The cost depends on the extent of the procedure, the method used, the amount of bone material from the tissue bank, and the type of membrane. A small augmentation performed simultaneously with implantation has a different price than an extensive block bone graft. An exact quote is provided individually after CBCT scan analysis.
Can bone grafting be avoided?
For single missing teeth with insufficient bone — usually not. Smaller defects can be augmented simultaneously with implant placement. Larger defects require prior augmentation. For complete edentulism with advanced ridge atrophy, there is an alternative: zygomatic or pterygoid implants, which bypass the atrophied bone and do not require grafts. This is a different clinical pathway, selected individually.
What materials do you use for bone augmentation?
In most situations, I use allogeneic bone from a certified tissue bank — human bone from a donor, processed and sterilized. Its biological structure promotes remodeling and gradual replacement with the patient's own bone. In selected cases, I use platelet concentrates CGF/PRF obtained from the patient's own blood. Collagen membranes are used to shield and protect the augmentation site.