Virtual planning and volumetric evaluation in the regenerative-reconstructive surgical treatment of a complex periodontal defect

Abstract

Aim: Our aim was to present the regenerative-reconstructive surgical treatment of a complex periodontal defect. Surgical treatment planning was carried out on realistic virtual hybrid models, containing all relevant anatomical structures (teeth, alveolar bone and gingiva). Additional aim was to evaluate the outcome of the surgical treatment, by the superimposition of pre- and postoperative cone-beam computed tomography (CBCT) scans. Materials and methods: Utilizing a semi-automatic segmentation method, the 3D model of teeth and alveolar bone was generated from the CBCT scan using the open source radiographic image processing software, 3D Slicer. Spatial registration of the hard tissue model acquired from the CBCT scan and the digital model acquired with an intraoral scanner was performed based on anatomical landmarks. First step of the planned stepwise surgical treatment was the extraction and simultaneous alveolar ridge preservation of tooth 26. Surgery was carried out according to the extraction site development (XSD) technique. Second step was the regenerative treatment of the horizonto-vertical periodontal defect involving tooth 24 and 25. Superimposition of the pre- and postoperative CBCT scans allowed to validate the volumetric and linear changes. Results: In the surgical area the cumulative hard tissue gain was 0.44 cm3. Crestal bone resorption of 0.11 cm3 occurred at the palatal and buccal aspects. Linear measurements were performed to evaluate the hard tissue fill of the periodontal defect around tooth 24 and 26. On average the intrabony component showed a 53.88 ± 36.84% of hard tissue fill, with minor crestal bone resorption. On average a 1.22 ± 0.87 mm of gingival recession occurred around the teeth. Conclusion: It can be concluded that hybrid models acquired with the aforementioned technique allowed detailed planning of the surgical procedures. With the application of the postoperative volumetric and linear evaluation, the healing dynamics of the complex defect could be demonstrated thoroughly.

Keywords

• virtual surgical planning
• regenerative-reconstructive periodontal surgery
• alveolar ridge preservation
• volumetric evaluation cbct
• segmentation
• 3d radiographic image reconstruction