Crestal bone changes around titanium implants: A methodologic study comparing linear radiographic with histometric measurements

Generally, endosseous implants can be placed according to a nonsubmerged or a submerged technique and in 1-piece or 2-piece configurations. Recently, it has been shown that peri-implant crestal bone reactions differ significa ntly radiographically as well as histometrically under such conditions and are dependent on a rough/smooth implant border in 1-piece implants and on t he location of a microgap (interface) between the implant and the abutment/ restoration in 2-piece configurations. The purpose of this study was to eva luate whether standardized radiography as a noninvasive clinical diagnostic method correlates with peri-implant crestal bone levels as determined by h istometric analysis. Fifty-nine implants were placed in edentulous mandibul ar areas of 5 foxhounds in a side-by-side comparison in both submerged and nonsubmerged techniques. Three months after implant placement, abutment con nection was performed in the submerged implant sites. At 6 months, all anim als were sacrificed, and evaluations of the first bone-to-implant contact ( fBIC), determined on standardized periapical radiographs, were compared to similar analyses made from nondecalcified histology. it was shown that both techniques provide the same information (Pearson correlation coefficient = 0.993; P <.001). The precision of the radiographs was within 0.1 mm of the histometry in 73.4% of the evaluations, while the level of agreement fell to between 0.1 and 0.2 mm in 15.9% of the cases. These data demonstrate in an experimental study that standardized periapical radiography can evaluate crestal bone levels around implants clinically accurately (within 0.2 mm) in a high percentage (89%) of cases. These findings are significant because crestal bone levels can be determined using a noninvasive technique, and b lock sectioning or sacrifice of the animal subject is not required. In addi tion, longitudinal evaluations can be made accurately such that bone change s over various time periods can be assessed. Such analyses may prove benefi cial when trying to distinguish physiologic changes from pathologic changes or when trying to determine causes and effects of bone changes around dent al implants.