To evaluate the effectiveness of the biologically oriented preparation technique (BOPT) in restoring traumatic tooth defects within the aesthetic zone, serving as a clinical reference.

This study has been reviewed and approved by the Ethics Committee, and informed consent has been obtained from patients. Two cases are detailed, involving traumatic tooth defects under the gingival level, repaired using BOPT in the aesthetic region. Both individuals reported defects resulting from trauma to the upper right anterior teeth occurring over a month prior. Case 1: male, 67 years old. The patient complained of a defect and exposed pulp in the right upper front tooth caused by trauma one month ago. Root canal treatment was performed in the dental pulp department, but there was no discomfort after the surgery. Due to the impact on chewing and aesthetics, restoration is required. Oral examination: 11 residual roots, the deepest part of the lip side fracture, in a V-shape, located 2 mm subgingival, 1-2 mm subgingival near and far, and 2-3 mm supragingival on the palatal side fracture. There is little remaining dental tissue, and filling material can be seen at the root canal opening. The proximal and distal diameters are small, and the tooth root is tilted towards the palatal side. After tapping (-), no obvious looseness is observed. 11 missing gingival papilla near and far; 21 dental crowns tilted towards the middle; thick gingival biotype; dental calculus (+), probing depth (PD): 2-4 mm; Attachment loss (AL): 1-2 mm; Gingival recession (GR): 0-1 mm; bleeding index (BI): 1-2, diagnosis: 11 residual roots; chronic periodontitis. Case 2, male, 34 years old. The patient complained of a defect and exposed pulp in the right upper front tooth caused by trauma one month ago. Root canal treatment was performed in the dental pulp department, but there was no discomfort after the surgery. Due to the impact on chewing and aesthetics, restoration is required. Oral examination: Large area defects were found in sections 12 and 13, with the lip side wall defect reaching about 1 mm subgingival and filling visible at the fracture end. The proximal and distal fracture ends were located about 2-4 mm above the gingiva, and the palatal fracture end was located about 3-4 mm above the gingiva. After tapping (-), no obvious looseness was observed, and the lip side gingiva was slightly red and swollen; thick gingival biotype; dental calculus (++~+++); PD: 3-5 mm; AL: 1-3 mm; GR: 0-2 mm; BI: 2-3; diagnosis: 12 and 13 tooth defects; chronic periodontitis. Treatment plan: following systematic periodontal treatment, the BOPT was implemented using vertical tooth preparation. Temporary restorations were employed to sculpt the soft tissue, and high-translucency zirconia all-ceramic crowns were selected. Utilizing computer aided design/computer aided manufacturing technology, the temporary restorations' contours were meticulously recreated to achieve optimal pink and white aesthetics.

The BOPT enables the restoration of traumatic tooth defects in the aesthetic area as well as soft tissue shaping. In Case 1, the patient's originally palatally inclined the upper right central incisor achieved gingival shaping and harmonized with the upper left central incisor. In Case 2, the previously swollen and poorly shaped gingival margins of the upper right lateral incisor and upper right canine showed significant improvement.By applying the BOPT, the two cases developed healthy soft tissue cuffs, achieving excellent pink and white aesthetic restoration effects. One-year postoperative follow-up of two patients showed that the gingival margins of the upper right central incisor in Case 1 and the upper right lateral incisor and upper right canine in Case 2 were stabilized, with good maintenance of pink and white aesthetic effects. The review of the literatures showed that compared to horizontal tooth preparation, the BOPT combined with a complete digital workflow can be more minimally invasive, using temporary restorations to rebuild the enamel-osteoskeletal contours of the abutment teeth, reshape the soft tissue contours, increase the thickness of the soft tissue, and stabilize the gingival margins. However, the long-term restorative effects still require clinical follow-up observation.

The BOPT is an effective restorative solution for traumatic teeth in the aesthetic area, as it can be used appropriately in the aesthetic area to obtain good aesthetic restorative effects.