Timing of Implant Placement after Tooth Extraction

Implant placement following tooth extraction can be classified into four protocols: Type I to Type IV (Hammerle et al., 2004).

 

Immediate Implant Placement (Type I)

• Healing Period Prior to Implant Placement: None
• Selection Criteria:
  • Intact facial bone wall with thick wall phenotype (>1 mm)
  • Thick, soft tissue biotype
  • No acute infection
  • Sufficient bone volume apically to stabilise the implant
• Surgical Aspects:
  • Flapless approach whenever possible
  • Internal augmentation
• Difficulty Level: Complex

Type I involves placing the implant immediately after extraction in the same surgical session. This approach reduces the number of surgeries and overall treatment time. However, it is technique-sensitive, with placement and anchorage potentially affected by site morphology and limited soft tissue for flap adaptation. Immediate placement may not prevent alveolar ridge modelling post-extraction, and evidence supporting concomitant regenerative techniques is inconclusive (Clementini et al., 2015). It is most effective with intact labial bone and thick gingival biotype (Kinaia et al., 2017) to minimise aesthetic complications.

 

Early Implant Placement with Soft Tissue Healing (Type II)

• Healing Period Prior to Implant Placement: 4-8 weeks
• Selection Criteria:
  • Thick or damaged facial bone wall
  • Sufficient bone volume to stabilise the implant in the correct 3D position
• Surgical Aspects:
  • Open flap procedure
  • Contour augmentation with GBR
• Difficulty Level: Advanced

Type II involves implant placement after soft tissue coverage of the socket, typically within 4-8 weeks. Advantages include increased soft tissue volume and the ability to assess the resolution of any infection. However, it extends treatment time and is technique-sensitive. This approach is preferable when there is sufficient bone volume available to stabilise the implant.

 

Early Implant Placement with Partial Bone Healing (Type III)

• Healing Period Prior to Implant Placement: 12-16 weeks
• Selection Criteria:
  • Large periapical bone lesion that precludes Type I or II placement
• Surgical Aspects:
  • Open flap procedure
  • Contour augmentation with GBR
• Difficulty Level: Advanced

Type III involves placing the implant after substantial bone fill in the socket, usually 12-16 weeks post-extraction. This method improves primary stability but extends treatment time, with variable resorption of socket walls during healing. It is suitable when large periapical lesions prevent Type I or II placement.

 

Late Implant Placement (Type IV)

With Prior Socket Grafting for Ridge Preservation

• Healing Period Prior to Implant Placement: 6 months or longer
• Selection Criteria:
  • Adolescent patients too young for implant therapy (<20 years)
  • Extended bone lesions apical and palatal to the root
  • Ankylosed root in apical position without bone volume apically
• Surgical Aspects:
  • Open flap procedure
  • Contour augmentation with GBR
• Difficulty Level: Advanced

 

Without Prior Socket Grafting for Ridge Preservation

• Healing Period Prior to Implant Placement: 6 months or longer
• Selection Criteria:
  • Extended delay in implant placement due to patient or site-related reasons
• Surgical Aspects:
  • If sufficient bone volume: Open flap procedure, contour augmentation with GBR
  • If insufficient bone volume: Staged GBR, followed by implant placement and further grafting for contour augmentation
• Difficulty Level: Complex

Type IV involves implant placement in fully healed sites after 4-6 months. This protocol allows for placement in clinically healed ridges with mature soft tissue but significantly delays treatment and may involve ridge resorption. It is suitable when other types are not feasible, allowing time for various treatment options and assessment of the healed ridge. Socket preservation techniques can help reduce bone resorption in extracted sockets.