Background/Aims: Traumatic dental injuries (TDIs) can result in complications that may manifest long after the initial injury. Long-term follow-up is essential. Registration systems must be easy to use. This study aimed to describe and validate a simple registration system for clinician-important TDI outcomes as an index. Materials/Methods: The clinical and radiological outcome findings were formulated with five digits in line with the Eden Baysal Dental Trauma Index. Twenty-five experts (n = 15 in a primary expert panel and n = 10 in a feedback panel) from seventeen countries participated in the validation process using the e-Delphi method. After two rounds to reach consensus, the second version of the proposed system was presented to the feedback group. The revised post-feedback version was re-evaluated by the primary experts. All experts commented freely and answered four questions on the system's use using a three-point Likert-scale. Results: The approved name of the proposed system is “Eden Dental Trauma Outcome Index”. The first digit reports the success of the restoration, and the second digit reports the healing type of root fracture. Coding the first two digits changed from Roman to Arabic numerals after the first round. The third digit records the external root resorption type with capitalised first letters of the two words describing the type. The fourth digit reports the maturity of the apex with lowercase first letters. The fifth digit records pulp status with Arabic numerals. Codes for unclear situations and tooth loss were added to all digits in the final version. All experts in the primary panel and 83.3% in the feedback panel reported that the index is practical but needs experience. Conclusion: After four validation rounds, the “Eden Dental Trauma Outcome Index” for reporting clinician-important outcomes was approved for face and content validity and external validity.