Effect of disinfection protocols on the dimensional stability of commercial vinyl polyether silicone impression materials: a systematic review and meta-analysis

To evaluate the association between chemical immersion disinfection and the dimensional stability of commercial vinyl polyether silicone (VPES; vinyl siloxanether) impression materials. PubMed/MEDLINE, Embase, Scopus and Web of Science were searched from inception to 30 April 2026, with Google Scholar used for supplementary citation and grey-literature screening. In vitro studies comparing disinfected and untreated or water-rinsed VPES specimens were included. Standardised mean differences (SMDs; Hedges’ g) were pooled using a random-effects model. Heterogeneity was assessed with I² and τ², and a 95% prediction interval was calculated. Subgroup analyses by disinfectant and immersion duration were considered exploratory. Six studies comprising 13 study arms included 206 disinfected and 206 matched control specimens. Disinfection was associated with greater dimensional change (SMD = 0.67, 95% confidence interval [CI]: 0.17–1.17; p = 0.0126), with substantial heterogeneity (I² = 75.8%; p < 0.0001) and a wide prediction interval (− 0.95 to 2.29). Sodium hypochlorite showed a larger pooled change (SMD = 1.56, 95% CI: 0.12–3.01) than glutaraldehyde (SMD = 0.26, 95% CI: −0.18 to 0.70). Material brand and consistency, disinfectant concentration, specimen geometry and measurement method contributed to heterogeneity. The larger effect in the 10-minute subgroup than in the 11–30-minute subgroup was confounded by disinfectant type and should not be interpreted causally. Chemical disinfection was associated with a statistically significant but heterogeneous dimensional change in the commercial VPES materials studied. Glutaraldehyde showed smaller average changes than sodium hypochlorite, but the wide prediction interval and methodological variability warrant cautious interpretation against accepted dimensional-change thresholds.