Abstract: Objective: To assess the accuracy of digital measurement of vertical mucosal thickness in the proposed implant area and to investigate the correlation between vertical mucosal thickness and the corresponding cortical bone thickness. Methods: Forty-eight patients who underwent digital tooth-supported guide implant surgery from January 2020 to June 2023 were selected for this study, and all the patients completed the collection of cone beam CT (CBCT) data and 3Shape mouth scan data, and the vertical mucosal thickness of the proposed implantation area was measured after the completion of the fitting in the 3Shape Implant Studio software and the corresponding cortical bone thickness (recorded as digital technometric method). Vertical mucosal thickness was measured intraoperatively using a modified periodontal probe embedded in a digitally guided plate guide ring (recorded as modified gingival puncture method). Differences and consistency between the two measurements of vertical mucosal thickness in the proposed implant area were assessed by paired t-tests and Bland-Altman analyses, and the correlation between vertical mucosal thickness and cortical bone thickness was analysed using the Pearson correlation coefficient. Results: The digital technique and the modified gingival puncture method had not significant difference in measuring vertical mucosal thickness in the proposed implant area (P>0.05) and showed good agreement. There was no significant correlation between vertical mucosal thickness and cortical bone thickness (P>0.05). Conclusion: The digital technique is an accurate method for measuring vertical mucosal thickness in the proposed implant area, and there is no significant correlation between vertical mucosal thickness and the corresponding cortical bone thickness.

Key words: cone-beam CT, intraoral scanner, vertical mucosal thickness, cortical bone thickness