Signal-to-noise ratios of 6 intraoral digital sensors

Abstract

Objective: The objective of this study was to compare the signal-to-noise ratios (SNRs) of 6 intraoral direct digital sensors. The sensors were Visualix 1, Visualix 2, DenOptix, Computed Dental Radiography (CDR), CDR APS, and Digora.

Study design: The sensors were exposed by using a dental x-ray machine operating at 50 kV, 8 mA and various exposure times. The phantom used was a hole measuring 1 mm in diameter and 1.25 mm in depth, drilled in a 10-mm-thick aluminum block. Digital images were transferred as 8-bit tagged image file format files and analyzed by using a personal computer.

Results and conclusions: SNR values increased up to a maximum value at a certain exposure level and then, depending on the system, either decreased or maintained a high level with increased exposure. The Digora system produced the highest SNR values over a large exposure range, whereas the Visualix 2 and DenOptix systems produced the lowest SNR values. The 2 CDR sensors produced rather high SNRs but over a very small exposure range.