Photoacoustic tomography versus cone-beam computed tomography versus micro-computed tomography: Accuracy of 3D reconstructions of human teeth

Objectives: In this in-vitro study, teeth were imaged using photoacoustic tomography (PAT), cone-beam computed tomography (CBCT), and micro-computed tomography (µ-CT). The study had the aim: to identify the best wavelength for PAT images to determine the accuracy of the three imaging methods and to determine whether PAT images of teeth can achieve acceptable reconstruction quality.  
Methods: Nineteen human mandibular single-rooted incisors were extracted from patients with trauma or periodontitis. To determine the best wavelength for acquiring photoacoustic images, all 19 teeth were scanned in vitro with PAT, using different laser wavelengths between 680 and 960 nm. The images were analyzed using image analysis software. To assess the accuracy of PAT and compare it with the accuracy of CBCT, each tooth was also scanned in vitro using CBCT and the reference standard technique of µ-CT. Subsequently, three different three-dimensional models, one for each imaging technique, were created fo...,
1.1 Sample preparation 

This study was conducted in compliance with the Declaration of Helsinki, and the use of extracted human teeth was approved by the Medical Ethics Committee of the University of Wuerzburg (application number 15/15). All patients provided written informed consent for the use of their teeth.
Nineteen human single-rooted incisors were extracted from the mandible of patients with trauma or periodontitis. After extraction, the teeth were cleaned by means of an ultrasonic scaler (SONICflex LUX 2000L, KAVO; Biberach, Germany). After cleaning, the teeth were stored for seven months in a 1% chloramine-T solution at 5ºC to prevent bacterial colonization.

1.2  Experimental Setup: µ-CT

To acquire µ-CT images, the teeth were scanned using a µ-CT device (MetRIC: Micro and Region of Interest CT, Fraunhofer IIS; Wuerzburg, Germany, Fig. 1a). The setup for µ-CT acquisition, which compromises source, sample, and detector (anode material: tungsten), is shown in Fig. 1a.
To acqu...,