皆さんこんにちは。
昨日今日の春の嵐はすごかったですね。
桜もすっかり散ってしまい
少し寂しい気持ちがします。
さて、今回も前回に引き続き
Factors affecting the long-term results of endodontic treatment
の結果（前半）になります。
The overall success rate of endodontic treatment in 356 cases which could be followed-up was 91% (Table 2). The success rate was 96% for roots with vital pulps which had to undergo root canal therapy. All roots with pulpal necrosis but without preoperative periapical lesions and 98% of the roots which underwent root refilling due to technical inadequacies showed normal radiological features in the periapical region at the follow-up examination. Eighty-six percent of the peripical lesions present in cases with pulpal necrosis healed after treatment. A still lower success rate (62%) was observed for roots with periapical lesions which were previously filled and were retreated. In other words, prognosis for the treatment was found to be significantly better for roots without apical radiolucency than for those with apical radiolucency (p <0.0001). For the roots with preoperative apical periodontitis, a statistical analysis of various factors which may influence the outcome of treatment was made using chi-square tests. The level to which it was possible to instrument the root canal had a significant influence on the prognosis of the treatment for roots with pulpal necrosis. When it was possible to instrument the canal to the apical constriction, 90% of the periapical lesions healed. Only 69% of the cases healed when it was not possible to instrument the canal to its total length. This difference was statistically significant (p = 0.002). The level of instrumentation had no influence when previously rootfilled teeth with periapical lesions were retreated. No distinction could be made in this study among canals obliterated by denticles, tertiary dentin, and/or obturations caused by improper instrumentation. The apical level of the root filling also had a significant influence on the outcome of the treatment for roots with necrotic pulps and periapical lesions (Fig. 2).
The best prognosis was found for roots in which the filling reached within 2 mm of the apex. Of these, 94% revealed normal periapical conditions at the follow-up examination. Corresponding figures for roots with excess root filling and for roots with fillings more than 2-mm short of the apex were 76% and 68%, respectively. These values were significantly different from the 94% success rate (p = 0.003 and p = 0.0004, respectively). The apical level of root filling had no significant influence on the outcome of treatment when previously root-filled teeth with periapical lesions were retreated (Fig. 3).
The technical standard of the root filling had no significant influence on the prognosis of the treatment for roots with pulp necrosis undergoing initial treatment (Table 3). However, for previously root-filled teeth which were retreated with adequate seal, the success rate (67%) was significantly (p =0.03) higher than for teeth inadequately sealed (31%). The preoperative size of the periapical lesion did not influence the outcome of the treatment for roots with necrotic pulps when treated for the first time (Table 4). However, only three lesions were initially larger than 10 ram. For previously root-filled teeth, the rate of success of retreatment for lesions with an average diameter of 5 mm or less was found to be 65%, compared with the 38% success rate for teeth with larger lesions (Table 4). This difference, however, was not statistically significant (p = 0.1).
つまり
根管治療全体の成功率は91％で
抜髄歯に限っては96％だった。
根尖病変の無い歯髄壊死歯は100%
根充不良の為再根充した根管治療歯は98%だった。
根尖病変がある場合（初回治療歯）の成功率は86%で
再根管治療歯は62%だった。
言い換えれば根尖透過像の有無が有意に治療の予後に影響を及ぼした。
歯髄壊死歯に関しては根管内器具の根尖への到達レベルが
治療の予後に有意に影響を及ぼした。
根尖病変がある場合、穿通症例は90%
未穿通症例は69%の成功率で、有意差があった。
しかし再根管治療歯においては器具の到達位置は成功率に影響を及ぼさなかった。
歯髄壊死歯と根尖病変のある歯においては
根充の根尖レベルが有意に成功率に影響していた。
予後が一番良かったのは根尖2mm以内に根充された時だった。
しかし再根管治療歯においては
根充の位置は成功率に影響を及ぼさなかった。
歯髄壊死歯・再根管治療歯共に術前の根尖病変の大きさは
治療の結果に有意に影響を及ぼさなかった
ということです。
最後の根尖病変の大きさは治療の予後に左右されなかった点が
とても興味深かったです。
原因の感染さえ除去できれば、吸収した歯周組織がどんなに大きくても
再生する可能性があることが分かりました。