Effect of Disinfectants on Tear Strength of Impression Materials

Disinfecting impressions is a common procedure to prevent transmission of pathogens to the dental laboratory. However some disinfectants may reduce the strength of the impression material and promote tearing when the cast is separated from the impression. OBJECTIVES: To compare the tear strength of elastomeric impression materials before and after disinfecting using two disinfectants. METHODS: 10 tear strength specimens were prepared for each material Examix/(GC America),  Aquasil Ultra/(Dentsply Caulk), Genie-Heavy Body/(Sultan Inc), Take 1/(Kerr), Affinis/(Coltene Whaledent), Elite HD/(Zhirmack), Impregum/(3M ESPE), using a notched plexiglass mold to produce 70x10x1.9mm samples with a 0.1mm center. The materials were mixed, placed in an incubator at 37⁰C until oral setting time per the manufacturer's directions. Five specimens of each material were disinfected with either Surflets/Sultan Health Care or Solo/Sultan Health Care disinfectants following manufacturer's instructions. The specimens were stored for 48hrs at room temperature and then loaded in tension until failure using an Instron (Model 5565) testing device at a rate of 500mm/min. Data were analyzed with two-factor ANOVA and Tukey Kramer analysis (p=0.05). RESULTS: There was no significant difference (p>0.05) in tear strength before and after disinfection of the materials tested. CONCLUSIONS: Disinfecting the elastomeric impression materials used in this study with the two disinfectants did not affect the tear strength of the impression material. These combinations of disinfectant and impression material can be used successfully. Supported in part by a grant from Sultan.