Human odontoblast cell numbers after dental injury

Objectives: The purpose of this study was to measure the changes in odontob last cell numbers in response to cavity restoration variables and patient f actors, and the effect these factors have on dental repair by tertiary dent inogenesis. The number of vital odontoblasts is a critical factor for pulpa l repair following restorative surgery, and yet little information is avail able on these cell numbers. Methods: Class V non-exposed cavities were prepared in the buccal surface o f intact first or second premolar teeth of 27 patients, between 9 and 17 ye ars of age. Following tooth extraction (28-163 days) the area of reactionar y dentine and the area of the odontoblasts were measured histomorphometrica lly. Results: Patient factors, as well as cavity preparation and restoration var iables, had little effect on the numbers of odontoblasts per pulpal unit ar ea. However, the age of the patient did appear to have an effect on the rea ctionary dentine secretory capacity of odontoblasts per unit area, and on t he relative number of odontoblasts beneath cut dentinal tubules. Conclusions: Odontoblast cell numbers were maintained following the prepara tion of cavities cut into dentine with a 0.5 mm residual dentine thickness. The repair capacity of the pulp-dentine complex would appear to be age dep endent, this may explain differences in the success of various restorative treatments between patients. (C) 2000 Elsevier Science Ltd. All rights rese rved.