Abstract:

Objective： To evaluate the bone alteration subject to remodeling and analyze the esthetic result following immediate implant placement of incisors. Methods: In this study, 20 patients (13 women, 7 men) were involved, who needed implants for incisors of maxilla. The patients received 23 immediate implants totally. On the day of surgery and 6 months after the implants were placed, Cone beam CT (CBCT) was taken. The thickness of the alveolar ridge and the vertical change of marginal bone levels onthe mesial and distal aspects of theimplants were measured using the computer software  (PlanmecaRomexis Viewer 3.6.0.R). The evaluation of esthetic result by labial convexity score (LCS) and papilla index score (PIS) were analyzed pre-operation and one year after the final crown was delivered. The statistics with paired-t test for the measurement data and Willcoxon test for rating data were done by SPSS 20.0. Results: The survival rate in the two-year follow-up was 100%. The measuring point 1 (MP1), MP2, MP3 and MP4 (0, 2, 4, 6 mm apical to the implant platform, respectively) got significant alterations after 6 months of the follow-up. These differences were statistically significant (P<0.05).The major alteration happened at MP1 and MP4, which got (-0.89±2.06) mm and (-0.75±1.28) mm reduction of the alveolar, respectively. The marginal alveolar ridge resorption was （-0.42±1.24） mm and（-0.91±1.96） mm for Ankylos System and Replace System, respectively, and the difference was not statistical significant . The esthetic results were quite acceptable. Before treatment, 18 incisors rated 3 for LCS，and 2 incisors rated 4 for LCS；after final restoration, only 5 incisors rated 3 for LCS, and 14 incisors rated 2 for LCS. Before treatment, 15 incisors rated 3 for PIS; after final restoration, 13 incisors rated 3 for PIS. There was no statistically significant difference for the PIS pre-operation and 1 year after final restoration, while there was statistically significant negative change for LCS. Conclusion: Even following the proper surgical technique, the alveolar ridge wall still can’t be maintained after immediate implant placed in fresh socket of incisors. The inter-dental papilla could be well maintained, while due to the remodeling of labial bone, labial convexity will inevitably collapse. Therefore immediate implant still has esthetic risk.

Key words: Dental implantation, Esthetics, dental, Alveolar process, Cone-beam computed tomography