Marginal bone loss as success criterion in implant dentistry: beyond 2 mm

AimThe aim of this study was to analyze marginal bone loss (MBL) rates around implants to establish the difference between physiological bone loss and bone loss due to peri-implantitis. Materials and methodsFive hundred and eight implants were placed in the posterior maxilla in 208 patients. Data were gathered on age, gender, bone substratum (grafted or pristine), prosthetic connection, smoking and alcohol habits, and previous periodontitis. MBL was radiographically analyzed in three time frames (5months post-surgery and at 6 and 18months post-loading). Nonparametric receiver operating curve (ROC) analysis and mixed linear model analysis were used to determine whether implants could be classified as high or low bone loser type (BLT) and to establish the influence of this factor on MBL rates. ResultsMarginal bone loss rates were significantly affected by BLT, connection type, bone substratum, and smoking. Bone loss rates at 18months were associated with initial bone loss rates: 96% of implants with an MBL of >2mm at 18months had lost 0.44mm or more at 6months post-loading. ConclusionImplants with increased MBL rates at early stages (healing and immediate post-loading periods) are likely to reach MBL values that compromise their final outcome. Initial (healing, immediate post-loading) MBL rates around an implant of more than 0.44mm/year are an indication of peri-implant bone loss progression.