Disinfection procedures: their effect on the dimensional accuracy and surface quality of irreversible hydrocolloid impression materials and gypsum casts

Objectives: This study primarily investigated the effect of disinfection procedures (Perform® and sodium hypochlorite) on the dimensional accuracy and surface quality of four irreversible hydrocolloid impression materials and the resultant gypsum casts. The antibacterial efficacy of the procedures was also studied. Methods: Dimensional accuracy was determined from the mean percentage deviation of six measurements taken from casts made from disinfected impressions compared with corresponding measurements from the master model and controls. Statistical analysis of data was determined by analysis of variance. Surface quality was determined using a stainless steel test block in accordance with ISO 1563. Results: The dimensional accuracy of the impression materials tested were of a comparable standard following disinfection. The surface quality of casts taken from Blueprint Cremix impressions were unaffected by the disinfection procedures. The remaining impression materials studied showed greater surface deterioration on casts following disinfection with sodium hypochlorite than immersion in Perform®. All disinfection procedures selected proved appropriate for antibacterial purposes. Significance: Individual analysis of impression materials is required to determine their suitability to a given disinfection protocol.