Diseases of Pulp and Periapical Tissues

Diseases of Dental Pulp Dental pulp is a delicate connective tissue liberally interspersed with tiny blood vessels, lymphatics, nerves, and undifferentiated connective tissue cells.

Etiologic factors Dental caries in which bacteria or their products invade the dentin and pulp tissue. Bacterial invasion in case of tooth fracture due to trauma or cracked tooth syndrome that expose the dental pulp to the oral environment. Bacterial invasion may also occur as a result of bacteremia & septicemia Chemical irritation of pulp caused by erosion or use of acidic restorative materials Severe thermal changes may also produce pulpitis Galvanic current transmitted to the pulp through metallic restoration – initiate pulpitis

Classification of Pulpitis Simplest division- Acute pulpitis Chronic pulpitis Extent of pulp involved- Partial or focal pulpitis – inflammatory process confined to a portion of pulp Total or generalized pulpitis – most of the pulp is diseased Presence or absence of direct communication between dental pulp and oral environment- Open pulpitis (pulpitis aperta) – communicates with oral cavity Closed pulpitis (pulpitis clausa) – no such communication

Focal Reversible Pulpitis Clinical features Tooth sensitive to thermal changes mainly cold Tooth show deep carious lesions, large metallic restorations or restorations with defective margins Histological features Dilatation of blood vessels Slowing of blood and haemoconcentration cause thrombosis Reparative dentin may be noted in the adjacent dentinal wall Treatment Carious lesion – excavated and restored Defective filling - replaced

Acute pulpitis Clinical features Histologic features Treatment Occurs in tooth with a large carious lesion Severe pain elicited by thermal changes especially on taking cold Pain lasts for 10-15 min. & intensity may be increased on lying down. Application of heat causes acute exacerbation of pain Histologic features Continued vascular dilatation accompanied by accumulation of edema fluid in connective tissue surrounding tiny blood vessels Pavementing of polymorphonuclear leucocytes apparent along the walls of these vascular channels Treatment No successful treatment Pulpotomy and placing a bland material that favors calcification (calcium hydroxide) over the entrance of root canals

Chronic Hyperplastic Pulpitis (Pulp polyp) Unique form of pulpitis wherein inflamed pulp, instead of perishing by continued suppuration, reacts by excessive & exuberant proliferation Clinical features Occurs exclusively in children and young adults Involves teeth with large, open carious lesions Pulp appears as pinkish-red globule of tissue protruding from the pulp chamber and not only fills the caries defect but also extends beyond May or may not bleed readily Most common – deciduous molars and first permanent molars Histologic features Hyperplastic tissue is basically granulation tissue Inflammatory cell infiltration – chiefly lymphocytes and plasma cells Treatment Extraction of tooth Pulp extirpation

Diseases of Periapical Tissues Acute apical periodontitis Chronic apical periodontitis Apical periodontal cyst Periapical abscess

Acute apical periodontitis Occur in patients of pulpitis Thermal change does not induce pain Tooth is elevated in its socket due to inflammatory edema and causes tenderness while biting or even to mere touch Radiograph appearance – normal except slight widening of periodontal ligament space Histologic features – vascular dilatation, infiltration with polymorphonuclear leukocytes Treatment – occlusal grinding if caused by occlusal trauma; tooth extraction or endodontic procedure if caused due to pulpal infection.

Chronic Apical Periodontitis (Periapical granuloma) Low grade infection and most common sequelae of pulpitis or acute periapical periodontitis Clinical features Involved tooth is non vital Slightly tender to percussion Percussion produce dull sound instead of normal metallic sound Mild pain on biting or chewing on solid food Tooth feels slightly elongated in its socket Radiographic features Appear as a radiolucent area of variable size seemingly attached to the root apex Histologic features Inflammation and locally increased vascularity Macroscopic or microscopic resorption of root apex Treatment Extraction of involved teeth Root canal therapy with or without subsequent apicectomy

Apical periodontal cyst (radicular cyst, periapical cyst, root end cyst) It is sequela of periapical granuloma originating as a result of bacterial infection and necrosis of dental pulp, nearly always following carious involvement of tooth. Clinical features Majority are aymptomatic Commonly seen between 20 and 60 years of age Most commonly involved teeth are maxillary anteriors Tooth is non vital or shows deep carious lesion or a restoration which is seldom painful or even sensitive to percussion Radiographic features Radiographic appearance is similar to periapical granuloma in most cases Cyst may be of greater size than granuloma Hiatologic features Similar to periapical granuloma Epithelium is stratified squamous Treatment Tooth extraction Pariapical tissue carefully curetted Root canal therapy with apicectomy of cystic lesion

Periapical Abscess (dentoalveolar abscess, alveolar abscess) Is an acute or chronic suppurative process of dental periapical region Clinical featues Initially tenderness of tooth which is relieved by application of pressure In time, tooth is extremely painful and is slightly extruded from its socket Radiographic features Usually no radiographic evidence of its presence Slight thickening of periodontal space Chronic abscess presents radiolucent area at the apex of the tooth Histologic features Are of suppuration composed of disintegrating polymorhonuclear leucocytes surrounded by viable leucocytes, occasional lymphocytes, cellular debris, necrotic materials and bacterial colonies Dilatation of blood vessels in periodontal ligament and adjacent marrow spaces of bone Treatment Drainage of abscess by either opening the pulp chamber or extracting the tooth Root canal therapy if lesion can be sterilized.