title: Immersion disinfection of irreversible hydrocolloid impressions in pH-adjusted sodium hypochlorite. Part 2: Effect on gypsum casts.
abstract: Lowering the pH of sodium hypochlorite has been shown to greatly improve its efficacy as a disinfectant for irreversible hydrocolloid. This study evaluated the surface roughness and detail reproduction of gypsum casts recovered from impressions disinfected with sodium hypochlorite at altered pH levels. The experimental disinfectants were sodium hypochlorite 0.525% (10-minute immersion) at pH 11.5 (unaltered), pH 10, and pH 8. An additional group was tested at pH 10 for 5 minutes. There was a trend toward increased surface roughness as the pH was lowered, but a 5-minute immersion of impressions in sodium hypochlorite at pH 10 produced casts of equivalent surface roughness to impressions rinsed in water and poured immediately. The test for surface detail reproduction produced similar results.
authors.affiliation: Lackland Air Force Base, San Antonio, Texas, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Hutchings
authors.forename: K S
authors.initials: KS
authors.lastname: Vandewalle
authors.forename: R S
authors.initials: RS
authors.lastname: Schwartz
authors.forename: D G
authors.initials: DG
authors.lastname: Charlton
mesh_terms: D000704:Analysis of Variance; D002133:Calcium Sulfate / Q000737:chemistry; D003102:Colloids / Q000737:chemistry; D019551:Dental Disinfectants / Q000737:chemistry*; D003760:Dental Impression Materials / Q000737:chemistry; D003761:Dental Impression Technique / Q000295:instrumentation; D004203:Disinfection / Q000379:methods*; D005069:Evaluation Studies as Topic; D006863:Hydrogen-Ion Concentration; D003765:Models, Dental; D009930:Organic Chemicals; D015203:Reproducibility of Results; D012973:Sodium Hypochlorite / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
chemical_list: D003102:Colloids; D019551:Dental Disinfectants; D003760:Dental Impression Materials; D009930:Organic Chemicals; C043594:Jeltrate; D012973:Sodium Hypochlorite; D002133:Calcium Sulfate