方法收集离体人前磨牙60个，随机分成6组。
Methods 60 human premolars were selected and divided into six groups by random.
目的：研究人前磨牙牙髓牙本质复合体的增龄性变化，探讨牙衰老和老年牙病的形态学基础。
Objective: to provide morphological basis for dental aging and senile teeth diseases and to study age-related changes of pulp-dentin complex of human premolar.
目的：研究人前磨牙牙髓牙本质复合体的增龄性变化，探讨牙衰老和老年牙病的形态学基础。
Objective: to provide morphological basis for dental aging and senile teeth diseases and to study age-related changes of pulp-dentin complex of human premolar.
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