Comparison of Peri-Implant Soft Tissue Parameters and Crestal Bone Loss Around Immediately Loaded and Delayed Loaded Implants in Smokers and Non-Smokers: 5-Year Follow-Up Results

Background: The aim of this study is to compare periimplant soft tissue parameters (plaque index [PI], bleeding on probing [BOP], and probing depth [PD] >= 4 mm) and crestal bone loss (CBL) around immediately loaded (IL) and delayed loaded (DL) implants in smokers and non-smokers. Methods: Thirty-one patients with IL implants (16 smokers and 15 non-smokers) and 30 patients with DL implants (17 smokers and 13 non-smokers) were included. Personal data regarding age, sex, and duration and daily frequency of smoking were gathered using a questionnaire. Peri-implant PI, BOP, and PD >= 4 mm were recorded, and mesial and distal CBL was measured on standardized digital radiographs. Multiple group comparisons were performed using the Bonferroni post hoc test (P < 0.05). Results: All implants replaced mandibular premolars or molars. Mean scores of PI (P < 0.05) and PD >= 4 mm (P < 0.05) were statistically significantly higher in smokers compared with nonsmokers in patients with IL and DL dental implants. The mean score of BOP (P < 0.05) was statistically significantly higher in non-smokers compared with smokers in both groups. CBL (P < 0.05) was statistically significantly higher in smokers compared with non-smokers in both groups. There was no statistically significant difference in PI, BOP, PD >= 4 mm, and total CBL among smokers with IL and DL implants. Conclusions: Tobacco smoking enhances peri-implant soft tissue inflammation and CBL around IL and DL implants. Loading protocol did not show a significant effect on peri-implant hard and soft tissue status in healthy smokers and nonsmokers .