Disinfection protocols during COVID-19 pandemic and their effects on prosthetic surfaces: a systematic review

To describe the possible adverse effects of sodium hypochlorite (NaOCl) solutions, high-concentration alcohol solutions, and povidone-iodine products, which are indicated for disinfection of inanimate surfaces against human coronavirus of the severe acute respiratory syndrome (SARS-CoV), on prosthesis materials, including zirconia, lithium disilicate, and acrylic resin.

A systematic literature research for articles published between January 2010 and February 2020 was conducted in Scopus, PubMed/Medline, Web of Science, Embase, and Science Direct using a combination of the following MeSH/Emtree terms and keywords: sodium hypochlorite, alcohol, ethanol, povidone-iodine, dental ceramic, zirconia, lithium disilicate, and acrylic resin.

A total of 538 studies were identified in the search during initial screening, of which 44 were subject to full-text evaluation, and 24 fulfilled the inclusion criteria. Seven articles on zirconia and lithium disilicate investigated the effect of NaOCl (0.5% and 1%), 96% isopropanol, and 80% ethanol on bond strength after saliva contamination. The remaining articles evaluated color alteration, surface roughness modifications, decrease in flexural strength, and bonding strength of all cleaning agents on acrylic resin.

NaOCl (1%) solution for 1 minute is recommended to reduce SARS-CoV infectivity and to minimize the risk of cross-contamination through prosthetic materials. The increase in surface roughness and color alteration were recorded using 1% NaOCl on acrylic resin, but this increase was not clinically significant. A decrease in bonding strength was determined after using 1% NaOCl, 96% isopropanol, and 80% ethanol solutions on lithium disilicate. Silanization before the try-in procedure and the application of the second layer of silane after cleaning methods are recommended to improve the bonding strength.