Possible mechanisms of lack of dentin bridge formation in response to calcium hydroxide in primary teeth

Introduction: The usage of Calcium hydroxide (CaOH2) has wide applications due to the property of osteo-inductive, protective, and antibacterial actions. However, it is not used in primary teeth, as it fails to form reparative dentin and the exact mechanism has not been explained. The hypothesis: The authors propose an explanation that lack of dentin bridge formation in response to (CaOH2) in primary teeth could be multifactorial: inability of the deciduous stem cells to generate complete dentin-pulp-like tissue; the absence of calcium-magnesium-dependent adenosine triphosphatase (Ca-Mg ATPase) in the odontoblasts; the pre-existing predilection of deciduous dentine pulp to form odontoclasts; the solubility of (CaOH2). Evaluation of the hypothesis: The hypothesis discusses the innate traits of the deciduous stem cells that lack the ability to form the dentin bridge, the absence of Ca-Mg ATPase enzyme and increased solubility of (CaOH2) together fail to stimulate the odontoblasts. Alternatively, pre-existing progenitor cells with proclivity to change into odontoclasts may cause internal resorption and hamper formation of reparative dentin.