Dental pulp vitality and dentin deposition in injured, immature teeth of dogs

This study was conducted to observe the reaction of dental pulp after tooth fractures in dogs in the first two years of age, at the time of the most intensive dentin production. The aim of the study was to compare the ability of dental pulp to survive and continue its dentin production during the main time of maturation. Twelve dogs were used in the study. Group 1 consisted of six dogs, aged 12 +/- 1 months, and Group 2 consisted of six dogs, aged 20 +/- 1 months. All procedures were carried out in anaesthetized animals. Seven teeth of each dog were fractured avoiding concussion-two incisors, two canines, and three premolars (third, fourth upper and third lower). The dental pulp was exposed by amputation of the coronal third of the crowns using a high-speed dental bur and extraction forceps, avoiding concussion of the dental pulp. Clinical and radiographic examination of the teeth was performed at monthly intervals for one year. All radiographs taken in the 1(st), 5(th) and 10(th) month of the study were processed and evaluated by computer programs. The results showed significant differences (F-test, P less than or equal to 0.01) in the viability of dental pulp between both groups despite relatively small difference in age. At the end of study the teeth that remained viable for 10 months in both groups of dogs had the same width of root canals despite the difference in the age of dogs and initial width of root canals. The viability of dental pulps seemed to be influenced mainly by the degree of concussion shock caused by trauma and tooth localization in the mouth cavity.