ミネラル三酸化物骨材を用いた歯尖端形成術後2.5年後の抜歯前大臼歯のマイクロコンピュータ断層撮影による観察

Observation of an extracted premolar 2.5 years after mineral trioxide aggregate apexification using micro-computed tomography.

• Gayeon Lee
• Chooryung Chung
• Sunil Kim
• Su-Jung Shin

抄録

ミネラル三酸化物骨材（MTA）を用いた歯尖端形成術については多くの研究が行われているが，抜歯後の直接観察はほとんど報告されていない．この症例報告は、2年半前に治療した下顎前大臼歯を矯正治療のために最近抜歯した症例である。12歳男児の右下顎前大臼歯の結節が骨折し、歯髄が露出していた。歯髄壊死と無症候性の歯周膿瘍と診断された。初診時に2.5%次亜塩素酸ナトリウムを用いた多量の灌水を行った．水酸化カルシウムペーストを腔内薬として使用した。3週間後の2回目の来院時には副鼻腔は消失していた。出血箇所にMTAを4mm厚の層として塗布し、その後3mm厚のグッタパーチャ充填とレジンコアのビルドアップを行った。2年半後、矯正治療のためにこの歯と他の3本の小臼歯を抜歯した。左右の下顎前歯をマイクロコンピュータ断層撮影でスキャンし、歯根の形状と歯根管の解剖学的構造を決定した。右下顎前歯の根の成長は不規則であり，根の輪郭は対側の歯とは異なっていた．MTAによる歯根尖化は、歯髄腔のない不規則な形態の根の形成につながる。

Although numerous studies have been conducted on apexification using mineral trioxide aggregate (MTA), direct observation of extracted human teeth after the procedure has been rarely reported. This case report describes a mandibular premolar treated 2.5 years ago and extracted recently for orthodontic treatment. The tubercle of the right mandibular premolar of a 12-year-old boy with dens evaginatus was fractured and the pulp was exposed. The tooth was diagnosed with pulp necrosis and asymptomatic periapical abscess. During the first visit, copious irrigation was performed with 2.5% sodium hypochlorite. Calcium hydroxide paste was placed as an intracanal medicament. The sinus tract had disappeared at the second visit after 3 weeks. MTA was applied on to the bleeding point as a 4-mm-thick layer, followed by a 3-mm-thick gutta-percha filling and resin core build-up. After 2.5 years, the tooth and three other premolars were extracted for orthodontic treatment. The right and left mandibular premolars were scanned with micro-computed tomography to determine the root shape and canal anatomy. Irregular root growth was observed and the root outline of the right mandibular premolar differed from that of the contralateral tooth. Apexification with MTA leads to the formation of roots with irregular morphology, without any pulpal space.

Copyright © 2020. The Korean Academy of Conservative Dentistry.