Respiratory Variations Within the Normal Dental Pulp

¹ Department of Oral Pathology, College of Dentistry, University of Iowa, Iowa City, Iowa

Oxygen consumption rates for basal, middle, and incisal thirds of rat incisor pulps show successively lower levels in progressing from the basal to the incisal end. The oxygen quotients determined for peripheral and central portions of dentinogenically active and quiescent bovine molar pulps show higher values in the peripheral portions especially in the dentinogenically active organs. It seems evident that the higher levels of respiration are related to dentinogenesis. Measurements of pulpal respiration over successive 10-minute intervals reveal noticeable variation of rates and occasional brief periods of suspension of oxygen consumption. Prominence of primitive anaerobic metabolic pathways and inherent partially deficient aerobic metabolism is suggested as a possible cause of this behavior. It is evident that QO₂ values of dental pulp are influenced by dentinogenic status, the region of the pulp from which samples are obtained, and the length of the period of measurement.