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Bone Remodeling around Implants Placed in Augmented Sinuses in Patients with and without History of Periodontitis

BACKGROUND
Susceptible individuals may be more prone to bone loss after augmentation procedures.


PURPOSE
Identify plausible clinical and biological factors influencing apical and marginal bone remodeling at implants placed in augmented sinuses, in patients with and without history of periodontitis.


MATERIALS AND METHODS
This prospective cross-sectional clinical study analyzed implant bone levels in a group of 104 patients with and without history of periodontitis undergoing 139 sinus augmentation procedures. Marginal and apical bone loss (MBL/ABL) was measured post-loading using a standardized digital technique. Measurements were taken preoperatively, at second stage implant uncovery, one year after loading and at an average of 53-months follow-up. Odds ratios were calculated to evaluate risks factors of contributing variables, such as, smoking, history of periodontitis, membrane perforation, surgical approach, grafting material, use of PRP, and implant design/dimensions.


RESULTS
Patients with history of periodontitis were 8.43 times more likely to present more than 2mm of MBL than patients without it (p =.041; CI95%: 1.09-65.12). Smokers were 4.97 times more likely to present over 2 mm of MBL than non-smokers (p =.003; CI95%: 1.70-14.54). Sinus membrane perforations were 11.4 times more likely to present ABL than those without perforation (p = 0.007; CI95%: 1.94-66.93). Mean MBL/ABL after 1-year post-loading and at last control were 0.49/0.56 mm and 0.67/0.46 mm, respectively. The use of a collagen membrane to cover the antrostomy and only xenograft as grafting material decreased ABL by 0.9 mm. The combination of autologous/xenograft bone was 4.04 times more likely to present higher ABL than xenograft alone (p = 0.023; CI95%: 1.21-13.45). Overall implant survival/success rates were 94.39%/91.33%, respectively.


CONCLUSIONS
Smoking and previous history of periodontitis negatively affects implant MBL. Sinus membrane perforation was associated with higher ABL. Lack of association between bone remodeling at marginal and apical areas suggests that they are different and independent processes.