Calcium silicate cement‐induced remineralisation of totally demineralised dentine in comparison with glass ionomer cement: tetracycline labelling and two‐photon fluorescence microscopy

Abstract

Two-photon fluorescence microscopy, in combination with tetracycline labelling, was used to observe the remineralising potentials of a calcium silicate-based restorative material (Biodentine(TM) ) and a glass ionomer cement (GIC:​Fuji​IX) on totally demineralised dentine. Forty demineralised dentine discs were stored with either cement in three different solutions: phosphate buffered saline (PBS) with tetracycline, phosphate-free tetracycline, and tetracycline-free PBS. Additional samples of demineralised dentine were stored alone in the first solution. After 8-week storage at 37 °C, dentine samples were imaged using two-photon fluorescence microscopy and Raman spectroscopy. Samples were later embedded in PMMA and polished block surfaces studied by 20 kV BSE imaging in an SEM to study variations in mineral concentration. The highest fluorescence intensity was exhibited by the dentine stored with Biodentine(TM) in the PBS/tetracycline solution. These samples also showed microscopic features of matrix remineralisation including a mineralisation front and intra- and intertubular mineralisation. In the other solutions, dentine exhibited much weaker fluorescence with none of these features detectable. Raman spectra confirmed the formation of calcium phosphate mineral with Raman peaks similar to apatite, while no mineral formation was detected in the dentine stored in cement-free or PBS-free media, or with GIC. It could therefore be concluded that Biodentine(TM) induced calcium phosphate mineral formation within the dentine matrix when stored in phosphate-rich media, which was selectively detectable using the tetracycline labelling.

Bonding to caries affected dentine

“…But in the case of Theracal as its hydration was compromised migration of elements may be a more probable cause for the increase in opacity. This is in agreement with recent studies where remineralization was observed in dentine following the placement of hydraulic calcium silicate-based dentine replacement materials [24,25]. In one of the studies intact dentine was used and calcium ion transfer was shown to happen together with the formation of calcium phosphate at the interface [25].…”

“…This is in agreement with recent studies where remineralization was observed in dentine following the placement of hydraulic calcium silicate-based dentine replacement materials [24,25]. In one of the studies intact dentine was used and calcium ion transfer was shown to happen together with the formation of calcium phosphate at the interface [25]. In the other study [24] the dentine was demineralized with formic acid.…”

Comparative evaluation of bioactive cements on biomimetic remineralization of dentin

“…Atmeh's study on the remineralization potential of Biodentine and glass ionomer (Fuji IX), on completely demineralized dentin showed the mineral formation of Ca-P like Raman peak related to apatite and most florescence intensity was represented by Biodentine treated dentin (26). Like the present study, Biodentine represented matrix remineralization, intra and peritubular mineralization in BSE-SEM.…”

Bond strength and adaptation of pulp capping materials to dentin

“…Previous studies have demonstrated the formation of a mineral infiltration zone at the calcium silicate cement–dentin interface and the production of tag‐like extensions within dentin tubules (Atmeh et al, ; Li et al, ). The migration of minerals from the capping materials to the adjacent dentin may increase bond strength.…”