歯髄の組織学的状態と知覚過敏試験に対する反応との相関性

Correlation between Histological Status of the Pulp and Its Response to Sensibility Tests.

抄録

はじめに:

この研究の目的は、歯髄の組織学的状態と相関させることによって、感性検査の精度を評価することである。

INTRODUCTION: The purpose of this study was to assess the accuracy of sensibility tests by correlating it with histologic pulp condition.

方法と材料:

歯周病、補綴、矯正の理由で抜歯予定の永久歯65本を対象に、臨床症状の評価を行った。正常歯髄と可逆性歯髄炎は治療可能な歯の状態とし、不可逆性歯髄炎と壊死は治療不可能な状態とした。その後，歯を抜歯し，歯髄の組織学的解析のために切片を作成した．組織学的状態および分類は，治療可能な歯髄の状態または治療不可能な歯髄の状態に対応した．組織学的な治療可能な歯髄状態と治療不可能な歯髄状態の比較は，感性検査の反応についてカイ二乗解析を用いて行った．また，各検査の陽性適中率（PPV），陰性適中率（NPV），治療可能な歯髄状態から治療不可能な歯髄状態を検出する精度を算出した．

METHODS AND MATERIALS: Assessment of clinical signs and symptoms were performed on 65 permanent teeth that were scheduled to be extracted for periodontal, prosthodontic or orthodontic reasons. The normal pulp and reversible pulpitis were considered as treatable tooth conditions while irreversible pulpitis and necrosis were considered as untreatable conditions. The teeth were then extracted and sectioned for histological analysis of dental pulp. Histologic status and classification corresponded to the treatable or untreatable pulp condition. Comparisons between histological treatable and untreatable pulp condition were performed with chi-square analysis for sensibility test responses. The positive predictive value (PPV), negative predictive value (NPV) and accuracy to detect untreatable from treatable pulp condition were calculated for each test.

結果:

温熱・冷熱試験において，正常反応と鋭い残光反応に有意差を認めた．また，EPTの陰性反応には組織学的に有意な差が認められた．歯髄状態の臨床診断と組織診断のカッパ一致係数は約0.843（<0.001）であった．治療可能な歯髄状態，治療不可能な歯髄状態を検出するための冷温試験とEPTの精度は，それぞれ78，74，62％であった．感性検査は，より高い確率で治療不可能な歯髄炎を診断した（熱，冷，EPTについて，それぞれNPV=63%-67%-54%，PPV=83%-91%-95%）．

RESULTS: A significant difference was detected in the normal and a sharp lingered response to heat and cold tests. There was significant difference in the negative response to EPT between histological groups. The kappa agreement coefficient between clinical and histological diagnosis of pulp condition was about 0.843 (<0.001). The accuracy of cold and heat tests and EPT to detect treatable pulp or untreatable pulp states were 78, 74 and 62%, respectively. The sensibility tests diagnosed untreatable pulpitis with a higher probability (NPV=63%-67% -54%, PPV=83%-91% -95% for heat, cold and EPT, respectively).

結論:

感性検査の結果は，歯髄疾患や治療不可能な歯髄の状態を診断する可能性が高いことが示された．しかし，診断精度を高めるためには，病歴，臨床症状，およびX線所見を感性検査と併用する必要がある．この小規模な研究の結果，臨床的歯髄診断と組織学的歯髄診断がよく一致することが示された．

CONCLUSION: Sensibility test results were more likely to diagnose pulpal disease or untreatable pulp conditions. However, to increase the diagnostic accuracy patient history, clinical signs and symptoms and also radiographic findings in conjunction with sensibility tests must be used. The result of this small study demonstrated a good agreement between clinical and histological pulp diagnosis.