Clinical Trial Qualifications

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.
• Clinical or radiographic evidence of root fracture or alveolar fracture.
• Tooth in question received prior endodontic obturation.
• Tooth in question has class III mobility or dens invaginatus.
• Tooth in question has a history of avulsion with extra-oral dry time longer than 1 hour.
• Clinical judgement (with documentation of the reason)
• Radiographic or clinical identification of ankylosis (replacement resorption) or inflammatory (infection-related) root resorption.