Direct pulp capping of a pulpal exposure during caries excavation has historically been considered unpredictable. Many materials have been used for direct pulp capping, including calcium hydroxide, hydrophilic resins, resin-modified glass ionomer cements, and tricalcium phosphates. More recently, mineral trioxide aggregate (MTA) has been used as a direct pulp-capping material. MTA resists bacterial leakage and may provide protection for the pulp and allow repair and continued vitality of the pulp if used in combination with a sealed restoration. In a study by Bogen, Kim, and Bakland, the use of MTA as a direct pulp- capping material was evaluated in 40 patients ages 7 to 45. In these patients, radiographs showed evidence of deep caries in close proximity to the pulp chamber with no evidence of thickened periodontal ligament, furcation radiolucencies, internal resorption, or periradicular pathosis. The objective of the study was to monitor pulpal survival time and to measure the outcomes against survival periods from previous studies using calcium hydroxide as the pulp-capping material. In this study, one clinician completed all direct pulp caps. Either a 5.25% or 6% NaOCl solution was used directly, or on a soaked cotton pellet, to achieve hemostasis. After hemostasis was achieved, the pulp exposure site and dentin were sprayed with water from a 2-way syringe and then air-dried. Gray MTA or white MTA was mixed, and a 1.5- to 3.0-mm-thick layer of the cement was placed directly over the exposure site and surrounding dentin; 1 to 2 mm of dentin and enamel was left circumferentially for placement of the future bonded restoration. After placement of the MTA, a flat cotton pellet moistened with water was placed directly over the material, and the tooth was provisionally restored. Patients returned for placement of the final self-etching composite resin res-toration within 5 to 10 days. Over an observation period of 9 years, 49 of the teeth were followed; the authors found that 97.96% of the teeth had favorable outcomes based on radiographic appearance, subjective symptoms, and cold testing. All teeth in the younger patients (15 teeth) that initially had open apices showed completed root formation. The study concludes that MTA can be a reliable pulp-capping material on direct carious exposures in permanent teeth when a 2-visit treatment protocol is observed.
(Source: Journal of the American Dental Association, March 2008)
