Does initial buccal crest thickness affect final buccal crest thickness after flapless immediate implant placement and provisionalization: A prospective cone beam computed tomogram cohort study

Background Flapless immediate implant placement and provisionalization (FIIPP) in the aesthetic zone is still controversial. Especially, an initial buccal crest thickness (BCT) of <= 1 mm is thought to be disruptive for the final buccal crest stability jeopardizing the aesthetic outcome. Purpose To radiographically assess the BCT and buccal crest height (BCH) after 1 year and to calculate the correlation between initial and final achieved BCT. Materials and Methods The study was designed as a prospective study on FIIPP. Only patients were included in whom one maxillary incisor was considered as lost. In six centers, 100 consecutive patients received FIIPP. Implants were placed in a maximal palatal position of the socket, thereby creating a buccal space of at least 2 mm, which was subsequently filled with a bovine bone substitute. Files of preoperative (T0), peroperative (T1) and 1-year postoperative (T3) cone beam computed tomogram (CBCT) scans were imported into the Maxillim (TM) software to analyze the changes in BCT-BCH over time. Results Preoperatively, 85% of the cases showed a BCT <= 1 mm, in 25% of the patients also a small buccal defect (<= 5 mm) was present. Mean BCT at the level of the implant-shoulder increased from 0.6 mm at baseline to 3.3 mm immediate postoperatively and compacted to 2.4 mm after 1 year. Mean BCH improved from 0.7 to 3.1 mm peroperatively, and resorbed to 1.7 mm after 1 year. The Pearson correlation of 0.38 between initial and final BCT was significant (p = 0.01) and therefore is valued as moderate. If only patients (75%) with an intact alveolus were included in the analysis, still a moderate correlation of 0.32 (p = 0.01) was calculated. Conclusions A moderate correlation was shown for the hypothesis that thinner preoperative BCT's deliver thinner BCT's 1 year after performing FIIPP.

Automated summary

This study radiographically assessed the BCT and BCH after 1 year and calculated the correlation between initial and final achieved BCT. The results showed a moderate correlation between thinner preoperative BCTs and thinner BCTs 1 year after FIIPP.