微创开髓及其牙体的应力分析的研究进展

微创开髓(conservative endodontic access cavity,CEC)是微创根管治疗术的第一步,经CEC治疗后的患牙较大程度保留了牙尖嵴和颈周牙本质等牙体硬组织,对于减少患牙的牙体流失及增强远期疗效具有重要意义。CEC存在多种入路方式及相应的洞型。确定髓腔入路的方法包括X线片定位法、显微CT/锥形束CT定位法以及数字化导板定位法。其中,X线片、显微CT/锥形束CT定位法操作简便,临床较为常用;而较为复杂的根管系统,利用数字化导板可建立更精准的开髓通路,减少牙体硬组织不必要的丧失,但数字化导板定位价格较高,临床上并未得到广泛的应用。CEC的洞型包括微创开髓洞型、超保守微创开髓洞型、"Truss"洞型以及切端洞型。CEC洞型与传统开髓洞型的应力分析目前以万能力学试验机加载离体牙、有限元分析法及临床观察为主,大多数学者的研究显示保留较多牙体组织的CEC可提高牙齿的抗折强度,但二者之间的抗折能力仍存在争议,在达到牙髓治疗目的与最大限度保留牙体结构之间如何达到平衡,仍需进一步的探索。

Research progress on conservative endodontic access cavities and its stress analysis of teeth

Conservative endodontic access cavity(CEC)is the first step of minimally invasive endodontics.After that operation,teeth retain the dental hard tissue,such as crest and peri?cervical dentin,to a large extent.It is of great significance to reduce the tissue excision and achieve a favorable prognosis.There are a variety of approaches and corre?sponding cavities in CEC.The methods to determine the medullary approach include X?ray localization,micro CT/cone beam CT localization and digital guide plate localization.Among them,X?ray film and micro CT/cone beam CT are sim?ple and commonly used in the clinic.For more complex root canal systems,the use of a digital guide plate can establish a more accurate pulp opening pathway and reduce the unnecessary loss of tooth hard tissue.However,the positioning price of a digital guide plate is high,and it has not been widely used in the clinic.The hole types of CEC include mini?mally invasive medullary hole type,super conservative minimally invasive medullary hole type,"Truss"hole type and cutting end hole type.The stress analysis of CEC and traditional endodontic access(TEC)cavity are mainly based on the loading of teeth by a universal mechanical testing machine in vitro,finite element analysis and clinical observation.Most scholars??studies have shown that minimally invasive endodontics can improve the fracture resistance of teeth,but the differential capacities of CEC and TEC remain controversial.How does on balance the purpose of pulp treatment and the maximum retention of tooth tissue?Further exploration is still needed.