松嫩地块位于兴蒙造山带东部,其内及周边地区早前寒武纪的岩石记录报道极少。笔者对黑龙江省龙江县大泉子屯碎裂岩化花岗岩进行年代学和地球化学研究表明,该岩石的锆石LA ICP MS U-Pb年龄为(2 579±15)Ma(n=20,MSWD=0.49),代表了花...松嫩地块位于兴蒙造山带东部,其内及周边地区早前寒武纪的岩石记录报道极少。笔者对黑龙江省龙江县大泉子屯碎裂岩化花岗岩进行年代学和地球化学研究表明,该岩石的锆石LA ICP MS U-Pb年龄为(2 579±15)Ma(n=20,MSWD=0.49),代表了花岗岩的结晶年龄,为新太古代晚期,地球化学特征显示该花岗岩为富钠花岗岩,具TTG中奥长花岗岩特征。本套新太古代花岗岩为松嫩地块及其周边地区的首次报道,证实了龙江地区存在早前寒武纪地质记录,为本区新太古代TTG岩石组合的寻找提供依据,也说明松嫩地块及其周边地区不仅存在古元古代岩浆活动记录、也存在新太古代岩浆活动记录,同时为松嫩地块及其周边大量的新太古代岩浆成因碎屑锆石的来源研究提供依据,为兴蒙造山带中残留的早期地质记录研究及兴蒙造山带的构造格局划分提供新材料。展开更多
AIM To compare the efficacy of resin composite restorations, retained with either polyethylene or zirconia-rich glass fiber posts. METHODS Sixty-two single rooted maxillary and mandibularcentral incisor teeth in forty...AIM To compare the efficacy of resin composite restorations, retained with either polyethylene or zirconia-rich glass fiber posts. METHODS Sixty-two single rooted maxillary and mandibularcentral incisor teeth in forty-four patients (15 males and 29 females; age range 15-32 years) were restored either with an ultrahigh molecular weight polyethylene(UHMWP) fiber post (Bondable Reinforcement Ribbon, DENSE, Ribbond, Seattle, WA, United States) or a zircon-rich glass fiber post (Snowpost, Lot H 040; Carbotech, Ganges, France). Then, direct resin composite restoration (Clearfil AP-X, Kuraray) was performed for both post systems in tooth color suitable. Patients were recalled for routine inspections at 6 mo, 1, 2 and 3 years.RESULTS The restorations were assessed during each recall evaluation according to predetermined clinical and radiographic criteria (periapical lesion; marginal leakage and integrity; color stability; surface stain and loss of retention of the post or the composite buildup material). The follow-up data showed no significant difference in these criteria between polyethylene fibre posts and zirconia-rich glass fibre posts.CONCLUSION The efficacy of resin composite restorations, retained with either polyethylene or zirconia-rich glass fiber posts were similar, suggesting that both types of fiber post can be used successfully to help retain resin composite restorations.展开更多
文摘松嫩地块位于兴蒙造山带东部,其内及周边地区早前寒武纪的岩石记录报道极少。笔者对黑龙江省龙江县大泉子屯碎裂岩化花岗岩进行年代学和地球化学研究表明,该岩石的锆石LA ICP MS U-Pb年龄为(2 579±15)Ma(n=20,MSWD=0.49),代表了花岗岩的结晶年龄,为新太古代晚期,地球化学特征显示该花岗岩为富钠花岗岩,具TTG中奥长花岗岩特征。本套新太古代花岗岩为松嫩地块及其周边地区的首次报道,证实了龙江地区存在早前寒武纪地质记录,为本区新太古代TTG岩石组合的寻找提供依据,也说明松嫩地块及其周边地区不仅存在古元古代岩浆活动记录、也存在新太古代岩浆活动记录,同时为松嫩地块及其周边大量的新太古代岩浆成因碎屑锆石的来源研究提供依据,为兴蒙造山带中残留的早期地质记录研究及兴蒙造山带的构造格局划分提供新材料。
文摘AIM To compare the efficacy of resin composite restorations, retained with either polyethylene or zirconia-rich glass fiber posts. METHODS Sixty-two single rooted maxillary and mandibularcentral incisor teeth in forty-four patients (15 males and 29 females; age range 15-32 years) were restored either with an ultrahigh molecular weight polyethylene(UHMWP) fiber post (Bondable Reinforcement Ribbon, DENSE, Ribbond, Seattle, WA, United States) or a zircon-rich glass fiber post (Snowpost, Lot H 040; Carbotech, Ganges, France). Then, direct resin composite restoration (Clearfil AP-X, Kuraray) was performed for both post systems in tooth color suitable. Patients were recalled for routine inspections at 6 mo, 1, 2 and 3 years.RESULTS The restorations were assessed during each recall evaluation according to predetermined clinical and radiographic criteria (periapical lesion; marginal leakage and integrity; color stability; surface stain and loss of retention of the post or the composite buildup material). The follow-up data showed no significant difference in these criteria between polyethylene fibre posts and zirconia-rich glass fibre posts.CONCLUSION The efficacy of resin composite restorations, retained with either polyethylene or zirconia-rich glass fiber posts were similar, suggesting that both types of fiber post can be used successfully to help retain resin composite restorations.
