A Novel Predictive Examination for Vital Bone in Grafted Sinus

Objectives: Introduction: In the 1980s Boyne and James described the bone grafting technique for the maxillary sinus, in order to solve the lack of bone and allow the installation of dental implants. This surgery was known as “Sinus Lift”. Still many questions of this procedure remain unanswered. One of the most important questions is: which is the best moment for implant installation?
Aim: To analyze whether there is a correlation between radiographic density and vital bone quantity.
Methods:
Methodology: Ten patients (3 male, 7 female, mean age 51) referred for “sinus lift”, with inorganic bovine bone (Bio-Oss, Giestlich®, Switzerland) were included. Twenty Implants were installed after 7-11 months of sinus lifting using a trephine for collecting a sample of tissue. Two scanned radiographs of the same patient (with and without the implant) were superimposed in layers using Adobe Photoshop software CS5. The areas of the implants were selected. The layers of the radiographs with the implants were then removed, resulting in the transfer of the implant area on the previous x-ray (without the implant). The radiographic density of this area was measured with a grayscale using Adobe Photoshop software CS5 and correlated to histomorphometric findings.
The Pearson correlation coefficient (r) was used to check for correlation between histomorphometric data and grayscale (radiographic density).

Results: Results: One implant was lost. Histomorphometric analysis showed an average percentage of vital bone was of 50.06%, the non-vital 40.17% and 9.44% for soft tissue. There was a strong (0.70) positive correlation between the radiographic density and the amount of vital bone.
Conclusions: Conclusions: The scanned periapical radiography showed potential application as a predictive non-invasive examination of vital bone percentage available after sinus floor elevation.