Evaluation of the effect of a remineralising paste containing strontium doped nanohydroxyapatite with Non-Collagenous protein analogue - chitosan on the characteristics of partially demineralized dentin -An invitro study

Abstract

Preservation of tooth structure by remineralisation of affected dentin can contribute greatly to the concept of minimal invasive dentistry. Remineralisation of dentin is a challenge due to the absence of seeding crystals. Biomimetic remineralising approach aids in restoring demineralised dentin close to that of normal dentin with the use of non-collagenous protein (NCP) analogues that stabilize the mineral phase of dentin resulting in intrafibrillar remineralisation. This study was done to assess the effect of a remineralising paste containing strontium doped nanohydroxyapatite (Sr-nHAp) with non-collagenous protein (NCP) analogue chitosan on the characteristics of partially demineralised dentin. Experimental pastes were formulated using 10 & 20% Strontium doped nano-hydroxyapatite (nHAp) with or without NCP analogue-chitosan. After characterization by x-ray diffraction, its remineralising efficacy on partially demineralised dentin was assessed through SEM-EDS analysis and nanoindentation and compared to that of demineralised and normal dentin. It was observed that 20% Sr-nHAp paste and the experimental formulations with Sr-nHAp and NCP analogue chitosan had the potential to remineralise the partially demineralised dentin specimens as observed by both increase in the mineral content noted in the SEM-EDS analysis and increased mechanical properties analysed by nanoindentation. Within the limitations of the study it was observed that Chitosan enhanced remineralisation potential of 10 & 20% Sr-nHAP and improved mechanical properties of partially demineralised dentin and hence has potential application as a remineralising agent and in vital pulp therapy procedures.