Immediate implants with guided bone regeneration in humans. A clinical and histological study

Aim of the study

This clinical case aimed to confirm if extraction followed by immediate implantation with simultaneous GTR could lead to bone regeneration and osseointegration.

Materials and methods

A patient presented with a fractured mandibular first premolar which had to be extracted. A plasma-coated titanium implant (IMZ) was placed at the time of the extraction and guided bone regeneration undertaken simultaneously. Porous hydroxyapatite (Interpore 200) was condensed on one side of the implant and the entire defect was covered by a Gore-Tex membrane. For financial reasons the patient accepted that the implant and regenerated tissues could be removed by block dissection and that a new regenerative procedure be undertaken to reconstruct the ridge in order to ultimately receive another implant.

Results

Histological examination of the specimen showed the presence of normal bone in the alveolus and healthy osseointegration, identical to that observed when an implant is placed in healthy bone. At the side of the defect filled with Interpore 200, osseointegration also took place and particles of the material were included in the vital regenerated bone. On two sides a space was observed between the polished surface of the collar of the implant and the regenerated bone, with or without the Interpore.

Conclusion

Regeneration is possible in a defect which can be isolated by a membrane, even without using graft materials under the membrane. Interpore 200 possesses a high degree of biocompatibility. Implantation and guided tissue regeneration are possible immediately after an extraction, even in the presence of considerable inflammation. The space between the bone and polished titanium collar of the implant was an artefact caused by dehydration of the specimen.

Commentary

Apart from the debatable ethics of this clinical case, in which an patient accepted the removal of tissue to avoid the cost of placing the second implant, the author provided no proof when he attributed the space which persisted between the regenerated bone and the polished titanium surface to an artefact and not to a biological phenomenon.