インプラント撤去・再植立にGBR法を併用した症例

―自家骨切削粉と吸収性HAPの使用経験―

抄録

The guided bone regeneration (GBR) technique has been used to promote the formation of new bone around endosteal implants that are exposed because of an insufficient amount of the alveolar bone, endosteal implants inserted in extraction sockets, or after the removal of endosteal implants.
A 58-year-old female was first examined in November 1982. In December, a BIOCERAM plate implant was placed in the mandibular left molar region and a bridge was seated. She had worn the implant for 14 years. In November 1996, the implant was removed because of surrounding bone resorption and replaced with three root form implants. At that time, an extensive bone defect was noted around the newly-placed implant in the mandibular left second premolar region. To promote the formation of new bone in the area of exposure, the GBR technique was performed using a GTAM (Gore-Tex tissue augmentation material) membrane, autogenous bone dust harvested with an osseous collection filter, and resorbable hydroxyapatite. As the patient was 72 years old, the formation of new bone required more time than that in younger patients. After 1 year, the GTAM membrane was removed during secondary implant surgery. In December 1997, the superstructure was seated.
There was no exposure of the membrane after primary surgery. The presence of sufficient newly-formed bone-like tissue around the exposed implant was confirmed by inspection and palpation. CT number and 3DCT in computed tomography revealed newly-formed bone in the defect around the replaced implant.
The GBR technique using autogenous bone dust, resorbable hydroxyapatite, and a GTAM membrane is effective for promoting the formation of new bone.