Outcome of formocresol/ZOE sub-base pulpotomies utilizing alternative radiographic success criteria.

The purposes of this investigation were to 1) measure success of a primary tooth pulpotomy technique that applies formocresol in the sub-base without the common five-minute application of a formocresol impregnated cotton pellet; and 2) compare success rates of the pulpotomy procedure using traditional criteria found throughout the literature with new criteria recently established, excluding internal resorption as a radiographic failure. Clinical and radiographic data were collected from a retrospective chart review of patients receiving formocresol pulpotomies with the application of formocresol in the zinc oxide-eugenol sub-base. Clinical and radiographic data were available for 196 primary molars in 122 children (followup=six to 103 months; mean=49 months). Traditional assessment of radiographic success and failure yielded a success rate of 79%. Alternative assessment excluding internal resorption as a failure yielded a 99% success rate. Most frequently observed pulpal responses were calcific metamorphosis and internal resorption. Overall clinical success was 99%. Two of the 196 teeth were extracted due to failure. A survival analysis demonstrated that the overall probability of survival remained high over time with a cumulative survival of over 95% after six years. The overall success rates in this study indicate that the formocresol pulpotomy technique incorporating formocresol in the zinc oxide-eugenol sub-base is a very successful treatment modality for primary molars requiring pulp therapy.