The Investigation Of Two Temporary Crown Materials In Interim Restoration Of Radiotherapy Patients With Nasopharyngeal Carcinoma

Objectives To determine the flexural strength of two temporary crownmaterials under the artificial saliva immersion condition．To evaluate theclinical effects of these two temporary crown materials in interim restorationof radiotherapy patients with nasopharyngeal carcinoma after the demolitionof fixed crown and investigate the designs of different types of dentitiondefects，the choice of materials，operating characteristics，restorationprocess.Methods The two kinds of temporary crown materials：Stellon acrylicresin and Luxatemp composite resin were used in this study．For eachmaterial，twenty rectangular specimens(the sizes25mm×2mm×2mm)werefabricated according to the ISO4049：2010standard and then were randomlydivided and stored into two groups(for each material：each group of10，being immersed in artificial saliva at37℃for24hours and30days). Theelectronic universal testing machine was used to test the flexuralstrength．109temporary crowns of Stellon acrylic resin in29patients withmany units and long crowns or bridges restorations were included in the study．37temporary crowns of Luxatemp composite resin in16patients withfewer units and front teeth restorations were included in the study．Theclinical restoration successful rates were evaluated about restorationintegrity，marginal adaptation，color，secondary caries，surface flatness whenthe radiotherapy completed（about2-3months）．And the patients appraisedfour subjective items about comfort degree，mastication，shape，color aboutthe fix of temporary crowns．Results There was significantly lower for the flexural strength ofStellon acrylic resin at soaking for30days than24hours（P＜0.05），therewas no significant difference for the flexural strength of Luxatempcomposite resins between soaking for24hours and30days （P＞0.05）．Flexural strength of Luxatemp composite resin was significantlyhigher than Stellon acrylic resin at soaking for24hour（sP＜0.05）and for30days（P＜0.01）. The clinical successful rates of restoration with the Stellonacrylic resin was94.5%，subjective satisfactions of patients：for shape，89.7%satisfied，for comfort degree，86.2%satisfied，for mastication，75.9%satisfied，for color，72.4%satisfied．The clinical successful rates ofLuxatemp composite resin was94.6%，subjective satisfactions of patients：for comfort degree and color，81.2%satisfied，for mastication and shape,75%satisfied．Conclusions Stellon acrylic resin and Luxatemp composite resin bothhave high flexural strength，for the interim restoration of radiotherapypatients with nasopharyngeal carcinoma，the clinical effects of Stellonacrylic resin used in many units and long crowns or bridges were restorationand Luxatemp composite resin used in fewer units and front teeth restorationwere all reliable and effective，which can be widely applied．...