1. Diseases of Pulp and Periapical Tissues

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

4. 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

5. 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

6. 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

7. 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 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

8. 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

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

10. 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.

11. 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

12. 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

13. 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.