Bone grafting and sinus augmentation in implantology

Immediate implantation into a tooth extraction socket

This technique involves placing an implant immediately after tooth extraction with the fixation of a temporary composite crown. It helps preserve the gingival contour and bone height while reducing overall treatment time. The implant can be placed precisely along the axis of the extracted tooth, ensuring proper distribution of the masticatory load.

Clinical steps:

1. Socket debridement and curettage.
2. Implant placement into the prepared site.
3. Suturing of the wound edges.
4. Radiological control of positioning immediately postoperatively.
5. Evaluation of results after 3 weeks (absence of inflammation, formation of gingival papillae, presence of attached gingiva).

Self-tapping root-form or tapered implants with a surface ensuring contact osseointegration are used for a successful procedure. The implant length must exceed the length of the extracted tooth root.

Contraindications include acute and chronic inflammation or tumors in the surgical area, as well as general contraindications to dental implantation.

Fixation methods and conditions for placement

Reliable primary stability is achieved through the use of self-tapping tapered implants with an advanced surface, as well as bicortical fixation.

Mandatory conditions for placement:

• Achieving primary stability in the freshly prepared bone.
• Thorough socket sanitation (voids are filled with bone-substitute material).
• Presence of at least 1.5–2.0 mm of bone around the implant (otherwise guided regeneration is required).
• Adequate coverage of the implant by the mucous membrane (gum grafting is sometimes required).

Implant immobilization can be achieved using temporary and permanent prostheses in compliance with occlusal requirements.

Guided bone regeneration (membrane technique)

Used when the bone volume is insufficient for placing an optimal implant. The essence of the method lies in placing a special membrane under the gum over the bone, while the space beneath it is filled with osteostimulatory material.

The membrane is sutured to the periosteum or fixed with titanium pins. An important rule: the membrane must not contact adjacent teeth so as not to disrupt the dentogingival junction.

Types of membranes:

• Resorbable (polymeric, collagen, lyophilized bone).
• Non-resorbable (pure titanium).

Materials for filling the submembrane space:

• Autograft: the patient's own bone (harvested from interdental septa, beneath the lower incisors, retromolar region, iliac crest, or rib). Yields the best results.
• Allograft: processed human donor bone (e.g., demineralized freeze-dried bone D.F.D.B.).
• Xenograft: bone of animal origin (bovine, porcine).
• Alloplast: synthetic materials (hydroxyapatite). Resorbable forms are preferred.

Sinus lifting (Sinus lifting)

Sinus lifting is a surgery to elevate the floor of the maxillary sinus to increase bone volume in the upper jaw. The choice of technique depends on the initial thickness of the bone tissue beneath the sinus:

• More than 10 mm: standard implantation.
• 8 to 10 mm (subantral placement): 10–11.5 mm implants are used. They are carefully advanced by 1–2 mm into the sinus. The bone floor is slightly perforated, but the sinus mucosa remains intact. Bicortical fixation.
• 5 to 8 mm (soft / closed sinus lifting): access to the sinus is achieved directly through the prepared bone socket for the implant, and the sinus space is reduced for bone augmentation.

Delayed implantation after osteoplasty

If immediate placement is not feasible, a delayed protocol is applied. Bone grafting is performed first, followed by a waiting period of 3–9 months. Afterward, the non-resorbable membrane is removed, the implant is placed, and another 3–6 months are awaited (the osseointegration period).

This approach allows placing the required implant in an ideal position without interfering with bone regeneration. However, it extends treatment time and requires additional surgical interventions.

An alternative for ridge defects can be implant placement with simultaneous defect filling using bone material and covering with a membrane attached directly to the implant. In case of a narrow alveolar ridge, ridge splitting with osteotomes is performed with simultaneous implant placement and filling of the gaps with bone-grafting material.

Briefly: answers to topical questions

Class and exam questions

What else to study on this topic

• Autogenous bone block harvesting technique (inlay technique).
• Features of working with demineralized freeze-dried bone (D.F.D.B.).
• The role of bone morphogenetic protein (B.M.P.) in osteogenesis.
• Technique of narrow alveolar ridge splitting.

Other topics from the section "Chapter 17. Dental Implantology (V.I. Olesova)"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.