Thick gingivae, an intact facial bone wall, sufficient bone volume on the apical aspect, no infection – ideal conditions for immediate implant placement. How to do it?
Ass. Prof. Stephen Chen | Australia
Immediate implant placement is a planned procedure and not something that should be done spontaneously without the proper pre-treatment diagnostic steps. With good planning, it is almost always possible to proceed with immediate implant placement unless complications occur as a consequence of the tooth extraction.
Extracting the tooth
If the root is ankylosed or part of the facial plate is damaged as a result of the extraction, then the implant placement may need to be delayed until additional healing has taken place. The extraction should be done carefully with fine luxators and root forceps.
Once the tooth has been extracted, the internal part of the socket should be carefully examined visually and with the use of a periodontal probe to look for defects and bony contours. The extraction should be done without flap elevation to reduce surgical trauma. This will also allow subsequent placement of the implant without a flap being raised to minimize surgical trauma.1
Placing the implant
A surgical guide is recommended to ensure that the implant is placed in the correct three-dimensional position. Due to the dense bone on the lingual aspect of the socket, there is a risk that the implant could deflect towards the facial side when it is inserted. This malposition can result in recession of the facial bone wall. The implant should be placed with the shoulder approximately 0.5 to 1 mm apical to the facial bone crest to compensate for the resorption that will occur.
Filling the gap
If the implant is placed correctly, a marginal gap of at least 2 mm will be present between the implant and the internal aspect of the facial wall. This marginal defect should be grafted with a bone substitute that has a low replacement rate, such as deproteinized bovine bone mineral (DBBM). Once the implant has been placed, the clinician has the option of attaching an immediate restoration to the implant. If this is done, care needs to be taken not to disturb the DBBM graft and to minimize the risk of bacterial contamination.
The crown of the maxillary left central incisor has fractured. The gingival phenotype is thick. In addition, the gingival margin is more coronal to that of the adjacent central incisor, a favorable situation for immediate implant placement.
A CBCT view of the maxillary left central incisor. The facial bone is 1 mm thick.
The tooth has been extracted without elevation of a flap. The walls of the socket can be inspected directly and with the use of a periodontal probe to ensure that all bone walls are intact.
The implant has been placed without flap elevation into an ideal 3-D position.
The marginal gap has been grafted with Geistlich Bio-Oss® to the level of the facial bone crest. The collagen matrix Geistlich Mucograft® Seal has been inserted into the gap between the healing abutment and the gingiva.
After 10 weeks of healing, the soft tissues healed uneventfully and were healthy.
At the two-year recall, the peri-implant tissues were healthy.
At the two-year recall, the radiograph showed ideal bone conditions.
At the two-year recall, the CBCT showed stable crestal bone at the neck of the implant plus the maintenance of a thick facial bone wall with the bone crest located coronal to the implant abutment interface (Photos: Stephen Chen).
Non-ideal conditions
When conditions are not ideal for immediate implant placement, early implant placement with either soft-tissue healing (type 2 according to ITI Treatment Guide2) or partial bone healing (type 3) should be performed instead. What are these non-ideal conditions?
From the previous discussion, soft tissue inflammation, the presence of acute infection, thin facial bone, damaged facial bone and lack of apical bone to anchor the implant would rule out an immediate implant approach. If there are extended defects, such as large periapical lesions or apical cysts, immediate implants are generally contraindicated.
Care should also be taken with multi-rooted tooth sockets. Whilst it is possible to place immediate implants into multi-rooted sockets, this should only be undertaken by clinicians who are very experienced with this approach. A much safer approach is to allow the socket to heal with partial bone regeneration over a period of 12 to 14 weeks (type 3 approach). The implant can then be placed in a good 3-D position and with good stability. The marginal defects become much smaller because of the spontaneous bone healing, often only requiring minor grafting to fill residual defects.
Ass. Prof. Stephen Chen | Australia
Melbourne Periodontal Specialists
Clinical Associate Professor at The School of Dentistry
University of Melbourne
Illustration Header : Alessandro Holler / Quaint
Comments
Fernan Lopez wrote:
"Dear Steve,
Answervery precise and predictable !
Best
Fernan"