Evaluation of the accuracy of spiral tomographic technique in estimating the height of maxillary alveolar bone for implant placement

Introduction: Before placing the dental implant, the surgeon needs to know the real height of bone in the site. Improper assessment of the distance between implant and vital structures can cause trauma to vital structures. The aim of this study was to determine the spiral tomography accuracy in evaluation of bone height in the posterior maxilla for placement of dental implants.Materials and Methods: In this descriptive cross-sectional study of 30 patients referring for implant placement 28 locations were selected for implant placement. All the patients underwent spiral tomography techniques and bone heights were reported. After implant placement the patients underwent panoramic radiographic techniques. Since the dental implant height was known the magnification of the panoramic radiographic technique in that area was determined. The bone height on the radiogram was determined in the area using a ruler at a magnification of ×3. Then the actual bone height was determined. Data was analyzed with paired t-test (α = 0.05). Results: Comparison of the values reported by the tomographic technique with the actual bone heights revealed a measurement error of 0.7 mm by the tomographic technique, which was statistically significant (p value = 0.031).Conclusion: Spiral tomography can accurately determine height of bone from the maxillary alveolar crest to the floor of the maxillary sinus, preventing damage to the maxillary sinus. Therefore, this radiographic technique can be used to determine the size of the implant needed to increase success rate. Key words: Dental implant, Radiology, Spiral tomography.