Regeneration of Pulp-Dentin Development in Teeth With Necrotic Pulps and Immature Roots

Inclusion Criteria: * Age 6-20 * Participant has a permanent tooth with a necrotic pulp (as defined by lack of responsiveness to both electrical pulp tests and cold \[EndoIce\] tests). If the tooth was traumatized, then pulpal necrosis is defined as either: 1) no response to both electrical pulp test and cold \[EndoIce\] test by three months after trauma, or 2) presence of a periapical lesion, or 3) radiographic evidence of root resorption, or 4) discoloration of the crown. * Tooth in question is restorable (as defined by Class A or Class B using Samet and Jotkowitz classification) without the need of a stainless steel crown. * Incomplete (i.e., immature) root development defined by apical foramen ≥1.0mm (each foramina \>1.0mm for multi-rooted teeth). * At least 5 mm of root development (CEJ to radiographic apex). * Willing and able to provide informed assent/consent. * Legal guardian willing and able to provide informed consent. Exclusion Criteria: * No access to telephone for study contacts. * Unable to comprehend study materials in English or Spanish. * Subject not available for follow up at 12 or 24 months. * Previous allergic response to ciprofloxacin, metronidazole or minocycline or any materials used in the study. * History of systemic diseases with altered immune function including diabetes, immunodeficiency, leukemia, Addison's or Cushing's disease. * History of taking immunosuppressants or chemotherapeutic agents including glucocorticoids in the past 3 months. * …