Table 1 The systemic inclusion and local exclusion criteria

1. Absence of systemic disease of relevant history of bad health (particularly ruling out bone diseases, uncontrolled or poorly controlled diabetes, unstable or life-threatening conditions or requiring antibiotic prophylaxis).

1. Radiolucent image greater than 1/3 of the root, metal artefacts.

2. Absence of history of radiotherapy or chemotherapy in the past 5 years

2. Severe root angulation (selected tooth image was not contained in slice).

3. Absence of autoimmune diseases and any drug use.

3. Severe root resorption.

4. Absence of pregnancy or lactation.

4. Radiographic evidence of surgical (guided bone/tissue regeneration) treatment in the anterior maxillary dentition.