犬におけるインプラント同時埋入自家骨リンググラフトにおける新しい切開とフラップデザインおよび第一段階創部剥離の影響評価

New Incision and Flap Designs in Autogenous Bone Ring Grafting with Simultaneous Implant Placement and an Evaluation of the Effect of First-Stage Wound Dehiscence in Dogs.

抄録

目的:

本研究の目的は、新しいタイプの切開とフラップデザインによる第一段階の創部剥離の防止効果を探り、創部剥離が自家骨輪移植の骨吸収に及ぼす影響を評価することである。

PURPOSE: The aim of this study was to explore the effect of preventing first-stage wound dehiscence with new types of incision and flap design and to evaluate the effect of wound dehiscence on the bone resorption of the autogenous bone ring graft.

材料および方法:

6頭のビーグル犬において、両側下顎の第2小臼歯と第4小臼歯を抜歯した。3ヵ月後、左側抜歯部位は通常の歯槽堤切開を行い、全層フラップを挙上した。右側は粘膜歯肉接合部を切開し、スプリットフラップを舌側へ、骨膜を頬側へ挙上しました。次にStraumann社製インプラント（. 3.3、長さ8mm）を埋入し、同時に自家骨輪移植を行った。次に、左側の傷は従来通り頬側フラップに骨膜リリースで閉鎖したが、右側の半厚膜フラップは隆起した骨膜で縫合した。3ヶ月後、動物を安楽死させ、採取したサンプルをマイクロコンピュータトモグラフィーと組織学で分析した。

MATERIALS AND METHODS: In six beagle dogs, the second and fourth premolars on the bilateral mandible were extracted. After 3 months, on the left extraction sites, conventional alveolar crest incisions were made and the full-thickness flaps were elevated. However, on the right sites, the incisions were made at the mucogingival junction, the split-thickness flaps were elevated toward the lingual side, and the periosteum was elevated toward the buccal side. Then, Straumann implants (. 3.3, length 8 mm) were placed with simultaneous autogenous bone ring grafting. Next, the wounds on the left side were closed with periosteal releasing on buccal flaps conventionally, but the semi-thickness flaps on the right side were sutured with the elevated periosteum. After 3 months, the animals were euthanized, and the harvested samples were analyzed using microcomputed tomography and histology.

結果:

新切開法群における創傷剥離の発生率は16.7％であり、従来法群（75％）に比べて有意に低い。創傷剥離のない症例では骨輪の垂直方向の骨量減少はほとんど認められなかったが，創傷剥離のある症例では骨輪の頬側で2.47 ± 0.17 mmという重度の骨量減少が認められ，舌側，内側，遠位のそれぞれ 1.37 ± 0.14 mm，1.00 ± 0.15 mm，1.03 ± 0.05 mmという値に比べ有意に高い値を示した．

RESULTS: The incidence rate of wound dehiscence in the new incision group was 16.7%, which was significantly lower than that in the conventional incision group (75%). There was hardly any vertical bone loss of the bone ring in the samples without wound dehiscence, but in wound dehiscence samples, severe bone loss, 2.47 ± 0.17 mm, was found on the buccal side of the bone ring, which was significantly higher than that on the lingual, mesial, and distal sides, 1.37 ± 0.14 mm, 1.00 ± 0.15 mm, and 1.03 ± 0.05 mm, respectively.

結論:

自家骨輪移植において、粘膜歯肉接合部切開と分厚いフラップデザインは、移植片の骨吸収に重要な役割を果たす第一段階の創傷剥離を効果的に防止することができる。

CONCLUSION: The use of a mucogingival junction incision and split-thickness flap design can effectively prevent first-stage wound dehiscence in autogenous bone ring grafting, which plays a key role in bone resorption of the graft.