Dental Pulp

The dental pulp is the soft connective tissue that forms the inner core of each tooth. It is divided in the coronal part and the radicular part depending on its position. At the root tip, the radicular part of the pulp merges with the periodontal ligament. At this site, blood vessels and nerves enter the tooth. At the interface of pulp and dentin lies a continuous row of columnar odontoblasts. They are responsible for the deposition of dentinal matrix that may be either secondary as a physiologic process continuing as long as the tooth lives, or tertiary as a reply to some insult. In the latter situation, they lose their regular palissading architecture and may lie embedded in the matrix they have deposited. In the pulp, calcified particles may form, the so-called denticles. They will be discussed more extensively elsewhere During and after eruption, the tooth pierces through the oral mucosa while reduced enamel epithelium and oral epithelium coalesce. To maintain an adequate barrier between the inner and the outer environment, there has to be a farm connection between the epithelial lining of the oral cavity and the surface of the tooth. This requirement is fulfilled by the so-called junctional epithelium, a rim of specialised multilayered nonkeratinising squamous epithelium that forms a cuf attached to and surrounding the necks of the teeth. In a healthy situation, this epithelium is attached to the enamel surface, forming a tapering end at the border between root cementum and enamel. At its opposite end, the junctional epithelium ends in a free margin where it merges with the epithelial surface of the free gingiva, the part of the gingiva that is connected to the tooth surface. This latter epithelium is parakeratinised and shows extremely long and thin rete ridges that may split into several branches. Both the epithelial covering of the free gingiva as well as the junctional epithelium are supported by collagenous fbres fanning out from the root surface and connected to the root through embedding in the root-covering cementum.

Te junction between epithelium and tooth is very vulnerable as it depends only on adhesion between both surfaces. Slight infammatory alterations in the gingiva may already cause disruption of this attachment. Te consequences of this disruption will be discussed under the heading gingival and periodontal disease. Briefy, if there is loss of attachment of the junctional epithelium to the tooth surface, it may move downwards to lie adjacent to the root cementum and may establish a new attachment at that site.