Pulp Polyp (Chronic Hyperplastic Pulpitis)
granulation tissue mass bulges from residual pulp
Introduction: Pulp Polyp
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Chronic (open) hyperplastic pulpitis, or pulp polyp, is an inflammatory proliferative response to infection of pulp tissues in a tooth with a very good blood supply and rapid carious destruction. It is essentially a pyogenic granuloma of the pulp tissue and is seldom seen in the teeth of older adults, partly because they are less likely than children to have rampant caries (those susceptible have already lost their teeth) and they lack the open or blunderbuss apices needed to bring an ample blood supply to the pulp tissue of the chamber. Many examples are covered by stratified squamous epithelium, and animal research has shown that sloughed keratinocytes are able to graft themselves to the granulation tissue surface and begin to proliferate.
The pulp polyp is typically found in the primary second molar or permanent first molar, because these teeth are more likely than others to be greatly destroyed by caries at an age when the apical blood flow into the tooth is still very good. This means that it is largely a disease of the first decade of life, although later lesions do occur. It is rarely seen after 20 years of age.
The lesion presents as a pedunculated hemorrhagic mass of granulation tissue arising from the chamber floor in a tooth with much or all of its crown destroyed (Figures 1 & 2, to left). Seldom is a polyp more than 0.7 cm. in size. Surface ulceration may appear as gray/white change or the surface could be the same color and appearance as the surrounding mucosa. Palpation often induces mild hemorrhage and there is no pain associated with it. Vitality testing of residual tooth parts will often show reduced responses, if there is a response at all. Occasional cases show polypoid granulation tissue bulging outward from a much smaller carious destruction. Bilateral cases have been reported.
The pulp polyp presents as a mass of edematous or fibrosing granulation tissue, admixed with a variable number of chronic inflammatory cells. Plump fibroblasts and endothelial cells are characteristic except in older lesions and blood vessels may be seen to radiate peripherally from a deep central location. The surface is usually ulcerated and covered by fibrinoid necrotic debris, but a third of the cases are covered by a relatively normal appearing stratified squamous epithelium. Presumably the epithelium creeps in from the surrounding mucosa or develops from sloughed keratinocytes which settle on the rich vascular environment of the polyp surface. The mass is by nature pedunculated, extending up from normal or slightly inflamed pulpal tissue in the root canals. Focal calcifications reminiscent of cementum or dentin may be seen as an aberrant repair attempt, especially toward the margins of the lesion.
The pulp polyp is treated by curetting the granulation tissue from the pulp chamber and performing endodontic procedures on the residual root structures, presuming the inter-radicular floor is still intact. Extraction is also a common treatment option. There is no malignant transformation potential and the lesion does not spontaneously regress.
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