comparison of strength and retention of fiberglass post in immediate and delayed post space preparation after endodontic treatment

Aims: root canal treatment is one of the treatments that weakens the tooth crown. the use of fiberglass posts has been considered due to its effect on the strength of teeth. the aim of this study was to evaluate the role of post preparation time on the strength and retention of fiberglass posts after endodontic treatment.materials & methods: in this experimental study, 48 samples were selected using convenience sampling method and randomly divided into two experimental groups of 24 samples (including immediate and 48 hours post space preparation after endodontic treatment). all samples were maxillary and single-channel. after roots preparation, the roots were washed with 5 ml of distilled water to remove debris and then dried with a paper cone (aria dent, iran). any residual goiter in the root wall was evaluated by radiography.findings: the mean strength (p=0.04) and the mean retention of fiberglass posts (p=0.001) in the group prepared immediately after the root canal treatment were significantly less than the group prepared 48 hours after the root canal treatment.conclusion: post preparation after 48 hours of root canal treatment can increase the strength and retention of fiberglass posts.