Effect of storage medium of extracted human teeth on the result of in vitro studies - a scoping review

This scoping review aimed to investigate how different storage media of extracted human teeth before and after preparation of specimens influence the outcomes of various dental materials intended for clinical application.

Literature search in four databases and by manual searching was carried out on a predefined PIO as follows: Population - extracted human teeth; Intervention - different storage media; Outcome(s) - material properties.

After screening 110 studies, 11 were included in the scoping review. Eight studies examined storage media effects before specimen preparation and three after specimen preparation. Four studies focused on enamel bonding, six on dentine, and one both on enamel and dentine. Concerning storage of extracted teeth prior to specimen preparation, cryopreservation, Chloramine T and thymol had no negative effect on bond strength to enamel. One study found Chloramine T to increase microleakage at enamel margins whereas another study found no negative effect. Storage in formalin, ethanol and thymol also had no negative effect on microleakage at enamel margins. Cryopreservation decreased bond strength to coronal dentine, but not to mid-coronal or deep dentine. Formalin, Chloramine T, ethanol and thymol had no negative effect on bond strength to dentine nor on microleakage at dentine margins. However, one study found long-term storage in Chloramine T to increase microleakage at dentine margins. Concerning storage of extracted teeth after specimen preparation, thymol significantly lowered bond strength to enamel, whereas formalin had no negative effect. Sodium hypochlorite had no negative effect on bond strength to dentine, and finally, formalin, Chloramine T, ethanol, and thymol had no negative effect on microleakage at dentine margins. Risk of bias assessment showed one high quality study, while the remaining 10 had questionable quality.

The effects of storage media on in-vitro dental material testing are variable and substrate-dependent, with dentine showing greater susceptibility than enamel. While distilled water and cryopreservation showed relative stability, other media like thymol and Chloramine T produced inconsistent results. Standardized protocols and further research are needed to ensure reliable and comparable outcomes.