Transient apical breakdown of a discoloured maxillary central incisor during orthodontic treatment: A case report.

Transient apical breakdown (TAB) appears to be a repair process taking place in the pulp and periapical area of traumatised teeth which may display crown discoloration and have no responses to pulp sensitivity tests. Few TAB cases induced by orthodontic forces have been reported so far. Presented is a case report in which TAB occurred on the maxillary right central incisor during orthodontic treatment. The affected tooth suddenly displayed crown discoloration and had no response to pulp testing at 6 weeks after the placement Invisalign Clear Aligner appliances. Condition of the discoloured tooth was monitored by periodic recall examinations without any active treatment. Six months after the occurrence of discoloration, the affected tooth recovered to its original shade and responded normally to pulp sensitivity tests.

Effect of Post Placement on the Restoration of Endodontically Treated Teeth: A Systematic Review.

PURPOSE: The aim of this study was to assess the effect of root canal post placement on the restoration of endodontically treated teeth. MATERIALS AND METHODS: PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, and two Chinese databases (China National Knowledge Internet and the Wan-fang database) were searched to identify randomized or quasi-randomized clinical trials related to post-and-core systems for the restoration of endodontically treated teeth. Studies published prior to August 2013, performed on humans, and written in English or Chinese were considered for inclusion. Two of the authors independently extracted data and assessed the quality of the selected studies. RESULTS: Three studies involving 317 participants were included in the review. Meta-analysis revealed that the risk of overall failure was greater with nonpost (104/271) than with post (78/377) restorations, irrespective of the number of remaining coronal walls (risk ratio [RR] = 0.41; 95% confidence interval [CI], 0.23 to 0.74). The risk of catastrophic failure was greater with nonpost (24/227) than with post (4/329) restorations, irrespective of the remaining coronal walls in restored teeth (RR = 0.11; 95% CI, 0.04 to 0.31). When three or four coronal walls remained, no catastrophic failure occurred in either the post group or the nonpost group. The difference in noncatastrophic failure between the two groups had no statistical significance no matter how many coronal walls remained (P > .05). CONCLUSIONS: Post placement appears to have a significant influence on reducing the catastrophic failure rate of endodontically treated teeth. When three or four coronal walls remain, post placement seems to have no influence on the restoration of endodontically treated teeth.