[Short-term and long-term effects of all-ceramic onlay on restoration of premolars and its influence on dental function].

PURPOSE: To investigate the short-term and long-term effects of all-ceramic onlay on restoration of premolars and its influence on dental function. METHODS: Ninety-five premolars receiving root canal treatment in People's Hospital of Peking University from January 2017 to January 2018 were enrolled, and randomly divided into two groups based on different repairing methods. Patients in the control group (n=47) received full crown restoration, while patients in the experimental group(n=48) received all-ceramic onlay restoration. The success, survival and failure rates of the teeth were compared. The United States Public Health Service(USPHS) and occlusal function of the prosthesis were compared 6, 12 and 36 months after treatment. The data were processed using SPSS 19.0 software package. RESULTS: The success and survival rate of the experimental group were higher than those of the control group, but without significant difference (P＞0.05). The morphology, marginal integrity, marginal coloration, surface texture, secondary caries, gingival health and proximal contacts showed no significant difference between the two groups 12 months after treatment(P＞0.05). Thirty-six months after treatment, the marginal integrity, marginal coloration and surface texture showed no significant difference between the two groups (P＞0.05), while the morphology, secondary caries, gingival health and proximal contacts were significantly better in the experimental group than in the control group (P＜0.05). The occlusal function between the affected side and contralateral side of both groups showed no significant difference 6, 12 and 36 months after treatment(P＞0.05). CONCLUSIONS: All-ceramic onlay restoration of premolars has high success and survival rate, and good short-term and long-term restoration effect, which is beneficial to improve the occlusal function of the affected teeth.

A novel role of human holliday junction resolvase GEN1 in the maintenance of centrosome integrity.

The maintenance of genomic stability requires accurate genome replication, repair of DNA damage, and the precise segregation of chromosomes in mitosis. GEN1 possesses Holliday junction resolvase activity in vitro and presumably functions in homology driven repair of DNA double strand breaks. However, little is currently known about the cellular functions of human GEN1. In the present study we demonstrate that GEN1 is a novel centrosome associated protein and we characterize the various phenotypes associated with GEN1 deficiency. We identify an N-terminal centrosome localization signal in GEN1, which is required and sufficient for centrosome localization. We report that GEN1 depletion results in aberrant centrosome numbers associated with the formation of multiple spindle poles in mitosis, an increased number of cells with multi-nuclei, increased apoptosis and an elevated level of spontaneous DNA damage. We find homologous recombination severely impaired in GEN1 deficient cells, suggesting that GEN1 functions as a Holliday junction resolvase in vivo as well as in vitro. Complementation of GEN1 depleted cells with various GEN1 constructs revealed that centrosome association but not catalytic activity of GEN1 is required for preventing centrosome hyper-amplification, formation of multiple mitotic spindles, and multi-nucleation. Our findings provide novel insight into the biological functions of GEN1 by uncovering an important role of GEN1 in the regulation of centrosome integrity.