Comparative analysis of S100 protein expression in healthy and irreversibly inflamed human dental pulps: A systematic review

The objective of this systematic review was to comparatively evaluate the presence of S100 proteins in dental pulps (DPs) from normal and irreversibly inflamed (asymptomatic as well as symptomatic) teeth. DP from human extracted teeth with a diagnosis of either symptomatic irreversible pulpitis (SIP) or asymptomatic irreversible pulpitis (AIP), in participants of any age or sex, irrespective of the type of teeth affected, were included. All published work, where English translation is possible, including in vitro as well as clinical studies, was incorporated (Till 31-07-2024). Data was retrieved independently by three reviewers, and any differences were clarified through discussion. The QUIN tool was applied for risk of bias (ROB) assessment. Five studies underwent statistical analysis and data extraction after pre-screening, the inclusion-exclusion criteria were applied, and the population, intervention, comparison, outcome (PICO) questions were addressed. Proteins S100-A1, -A2, -A3, -A4, -A6, -A8, and -A9 were substantially less prevalent in permanently inflamed DP than in normal DP at several anatomic locations. S100-A7 detected certain trends, although they weren’t very noticeable. In the pulpal stroma, S100-A1, -A2, -A3, -A4, -A8, and -A9 proteins were shown to be substantially more prevalent in AIP and SIP specimens than in normal pulp (NP) specimens. In the odontoblast layer, S100-A1, -A6, -A8, and -A9 were shown to be substantially less common in SIP than in NP, whereas S100-A9 was found to be much less common in AIP than in NP. Under specific circumstances, S100-A1, -A2, -A3, -A4, -A6, -A8, and -A9 appear to be involved in the development of pulp stones and localized calcification processes of the DP.