Objectives: To determine rates of pulpal exposure during caries removal with an excavator or a bur, to assess success rates of vital pulp therapies in both cases, to analyze pulpal bleeding as an indicator of primary teeth treatabilioi. Study Design: Of the 352 primary mandibular molars with deep carious lesions, 141 with pulp exposed during the removal of caries were grouped according to type of instrument causing pulpal exposure and existence of bleeding at the exposure site. Teeth suitable for direct pulp capping or formocresol pulpotomy were treated and followed up for two years. Results: The difference between the rates of pulpal exposure with an excavator (52.5%) or a bur (47.5%) was insignificant. The treatment success rate of teeth with pulp exposed by an excavator (15.8%) was significantly lower than teeth with pulp exposed by a bur (48.8%), regardless of whether bleeding existed at the exposure site or not; however; when bleeding existed this difference was insignificant (15.8% and 40.6%, respectively). Conclusions: Pulpal exposure possibility during caries removal caused by an excavator and a bur was similar, the treatment success rate was lower when the exposure was caused by an excavator; the existence of pulpal bleeding resulted in mistakes in diagnoses.