Purpose: to make a more accurate assessment of the status of pulps from teeth with periodontal lesions.
❖ N= 85 periodontally involved teeth (Deep pocket, mobility, resorption…) examined histologically.
-53 had carious lesions, restorations, or both
-32 teeth free of cavities or operative interference.
Lateral and Accessory Canals:
→More in posterior and occasionally in anterior teeth.
•In molars: -multitude of accessory canals
-Lateral canals in bifurcation or trifurcation areas.
•These Canals filled with capillaries, pulp cells, ground substance, and fibers.
•When nutrition of pulp interfered with through involvement of these foramina by periodontal disease, small regions of necrosis or infarction occurred within pulp, causing pulp-tissue breakdown, fatty degeneration, and calcification.
Effect of periodontal lesion on pulp: In periodontally involved teeth:
– Intact, uninflamed, and unaffected pulps were only (6%).
-(49%) had inflammation.
-Atrophic pulps in (27%)
-Totally Necrotic pulps (18%).
–Abundant dystrophic calcifications, completely obliterating coronal portions of pulp and heavily infiltrating fibrous tissue in roots.
-Formation of Reparative dentin. →Canals appeared completely calcified in RG.
-Periodontal lesions produce degenerative effect on dental pulps.
• Effect of periodontal lesion on pulpal lesion
-Pressure atrophy have occurred because of mobility
-This affected BV and reduced vascular supply resulting in vascular atrophy
-There was Resorption on side of roots adjacent to granulation tissue.
-When periodontal lesions were deep, resorption was found also within root canals
-Disturbance of blood supply for a small area of the pulp lead to death of cells which eventually resulted in coagulation necrosis.
-Local medication is another cause of injury and necrosis of pulp cells.
-Microorganisms in periodontal lesions able to produce necrosis of cells.
• Response to heat and cold
-Among all periodontally involved teeth, normal responses to applied heat and cold obtained from 4 out of 5 teeth with intact, un-inflamed pulps.
–Atrophic teeth (22): 11 react normally, 10 abnormal, 1 no response.
–Abnormal reactions to thermal tests increased sharply in all inflammatory states (statistically significant)
-Thermal responses in teeth with periodontal lesions increased significantly when pulps inflamed
–Teeth without caries or restorations, 15 (50%) respond normally to applied heat and cold, 3 no response, 12 abnormal response. →Greatest abnormal responses occurred in teeth with atrophic pulp (7/11)
• Patients’ complaints:
-Most increased pain from cold those with atrophic pulps (6 cases).
-In most instances patients complained of pain on application of both heat and cold.
-Patients, with intact and uninflamed, mildly inflamed, or necrotic pulps (that is, those whose pulps were not atrophied or severely inflamed) did not report increased pain to thermal stimuli.
→Same in Periodontally involved teeth free of caries or restorations. →Thus, patients’ complaints relating to pain on thermal stimuli cannot be used as indicators of pathologic state of pulp in periodontally involved teeth