Impact of various storage media and time on mechanical properties of bovine root dentin

In-vitro-studies usually require extracted teeth, which have been stored over an extended period of time. It can be assumed that storage solutions and time may alter the mechanical properties of dentin. The aim of this study was to examine Martens hardness parameters of bovine dentin with regard to the storage medium and storage time for up to 6 months. Standardized root dentin bars from extracted bovine incisors were stored in thymol 0.1%, chloramine-T 0.5%, formalin 10% and double distilled water. At baseline and after storage periods of 1, 3, and 6 months, samples were analyzed regarding Martens hardness, indentation hardness, indentation modulus, and indentation creep (linear mixed-effects regression models). Within 3 months of storage at the latest, all solutions showed significantly reduced values for Martens and indentation hardness. Regarding the indentation modulus, a reduction was observed for all groups at 6 months at the latest. In general, chloramine-T was shown to have the least impact on the mechanical properties of bovine dentin. Within the limitations of this study, storage medium and time should always be considered when conducting studies on the mechanical properties of bovine dentin, including any unfavorable changes of the dental hard tissues.