Evaluation of Radiopaque Markers for Edentulous Patients using Computed Tomography

Objectives: Diagnosis and treatment planning for edentulous patients requires 3-dimensional radiographic evaluation of bone resorption. Because computed tomography (CT) has good reproducibility and high accuracy, it generally provides exact form measurements. However, it is difficult to obtain exact measurement of a jawbone sectional form in cases of edentulous patients. With the increased use of CT for diagnosis of edentulous patients, there is a need for development of radiopaque markers with low artifact production for radiographic examination. The purpose of the present study was to evaluate the CT characteristics of silicone materials for form measurement of edentulous jawbone.

Methods: The specimens of the following 6 silicone materials were used: Fit Checker (FC), Exafine regular (ER), Cortex fine (CF), Memoreg2 (MR), Correct PULS (CP), Realbite (RB). FC, ER and CF are used for impressions, and MR, CP and RB are used for maxillomandibular records. Spiral CT data was performed with the following settings: voltage, 120 kV; current, 25 mA; slice thickness, 1 mm; table speed, 1 mm/s. CT values were compared among the 6 silicone materials. Statistical analysis was performed using the Mann-Whitney U-test at a significance level of p =0.05.

Results: Among the silicone materials used for impressions, FC had the greatest CT value. FC had a significantly higher CT value than EF and CF (p<0.05). Among the silicone materials used for maxillomandibuler records, CP had the lowest CT value. CP had a significantly lower CT value than MR and RB (p<0.05).

Conclusions: Among the silicone materials used for impression, FC appears to be the most suitable for markers in edentulous jawbone measurement using CT. The CT values of MR and RB were approximately equal to the CT value of bone, indicating that they are the most suitable materials for maxillomandibular records.