今回は、歯内療法後に行ったグラスファイバーポスト修復の生存率
に関する文献です。
.
計149本のポストに関して10年間追跡調査を行っています。
術前に、歯種（前歯または臼歯）、ポストの種類（3つのメーカーを使用）
ポスト径（1mm,1.25mm,1.5mm）、隣在歯接触点の有無
フェルールの有無等のデータを集め
コックスの比例ハザードモデルを用いて
これらと失敗までの期間との関連性を評価しています。
Glass-fiber-reinforced endodontic posts (GFRPs), in combination with composite resin core materials, are commonly used to build up damaged endodontically treated teeth. However, long-term clinical data are scarce. Thus, the aim of this investigation was to evaluate the survival of 3 different GFRP systems, taking into account several other relevant factors.
One-hundred forty-nine GFRPs in 122 patients were followed for up to 120 months. GFRPs were adhesively luted using the etch-and-rinse technique. The core was built with a chemically curing composite resin and restored according to the specific prosthetic treatment plan. Cox proportional hazards models were used to evaluate the association between clinical variables and the time until failure.
Within 10 years, 55 failures could be observed (annual failure rate = 4.6%) with the most frequent ones being post fracture, loss of post retention (both n = 17), endodontic problems (n = 7), and those resulting in tooth extraction (n = 10). Sixty posts could be followed up for 105 to 120 months (34 posts lost to follow-up, [mean (standard deviation) survival time: 74 (43) months]). In crude analyses, only the tooth type in favor of posterior teeth compared with anterior teeth and the number of remaining cavity walls (in favor of ≥ 1 compared with no wall) were significantly associated with the failure rate. Cox regression analysis revealed a significant hazard ratio of 2.0 (95% confidence interval, 1.1-3.5; P = .021) for tooth type in favor of posterior teeth.
The relatively high annual failure rate of GFRPs highlights that the treatment decision should take into account the most relevant factors as tooth type and the number of remaining cavity walls.
つまり
10年間で失敗した55本の種別は右表の様になりました。
なお失敗の定義は、ポストの維持の喪失、ポストの破折
歯内療法の失敗、治療計画の変更もしくはコア築造の失敗とされています。
..
術前に集めた項目の中で、失敗率を有意に上昇させたのは
歯種（前歯が臼歯の約2倍）とフェルールの有無
（0壁の場合は1壁以上有る場合の約2倍）ということでした。
.
特に歯種に関しては、力の観点から
前歯部は引っ張り応力を引き起こす水平方向に
力が加わりやすい為、疲労破折が生じやすいことが
関連しているのではないでしょうか。
.
引用文献
Naumann M, Koelpin M, Beuer F, Meyer-Lueckel H.
10-year survival evaluation for glass-fiber-supported postendodontic restoration: a prospective observational clinical study.