Cervical wear and occlusal wear from a periodontal perspective

Summary The aim of this study was to investigate whether cervical wear was associated with occlusal wear and clinical periodontal parameters in relatively older adults. A total of 30 patients, with multiple non‐carious cervical lesions (NCCLs) and without a disease or condition that could cause heavy tooth wear, were included in the study. The periodontal parameters including plaque index, probing pocket depth, gingival recession (GR) and tooth mobility were obtained from 641 teeth of which 475 (74·1%) displayed NCCLs. The levels of cervical wear and occlusal wear were determined according to a tooth wear index. Premolars were more likely to develop cervical wear than canines, molars and incisors. Cervical wear was significantly associated with less plaque accumulation and the presence of shallow pockets. The teeth with advanced GR and without increased mobility were 2·583 and 1·715 times more likely to develop deeper cervical lesions, respectively. Age and the level of occlusal wear were not linked to the bucco‐lingual depth of cervical wear. In conclusion, the significant association of advanced cervical wear with the relatively healthy periodontal status suggested the role of abrasion and its possible combined action with erosion in the aetiology of NCCLs. The rate of GR and the lack of tooth mobility could constitute predisposing factors for the progression of cervical wear because the exposed root surfaces could be more susceptible to abrasion and/or erosion, and the non‐mobile teeth resisting strongly against frictional forces, thus abrasive effects, could possibly develop cervical wear.     

白藜芦醇保护缺血再灌注大鼠心肌作用与miR-21的相关性

目的 观察白藜芦醇预处理后大鼠心肌微小RNA(miRNA)的表达变化,分析白藜芦醇介导的心肌保护作用与miR-21之间有否关系.方法 通过miRNA芯片微阵列方法和qRT-PCR检测并验证白藜芦醇灌胃预处理后的大鼠心肌miRNA表达谱；建立大鼠心肌缺血再灌注损伤模型,检测各组心肌梗死面积、心肌细胞凋亡率以及miR-21的表达水平.结果 白藜芦醇预处理后,大鼠心肌的miR-21表达水平约为对照组的2.5倍;miR-21阻逼剂对白藜芦醇预处理引起的miR-21高表达产生了明显的抑制作用；过表达的miR-21显著降低了心肌细胞凋亡率,心肌组织梗死面积明显缩小.结论 白藜芦醇可以调控心肌多种miRNA的表达水平,通过促进miR-21的表达,白藜芦醇能够抑制心肌细胞的凋亡,从而减轻缺血再灌注对心肌的损伤.