The relationship between enamel and dentin calibrated-radiographic-density measured by cone beam computed tomography and dental caries status in young adults

Abstract

Objective: To evaluate the relationship between caries experience measured by the decayed missing filled teeth (DMFT) index and the radiographic density of dental hard tissues measured by cone beam computed tomography (CBCT) with a novel calibration tool for individuals aged > 20 to 25 years.

Materials and methods: The sample consisted of 40 patients. Their DMFT ranged from 1 to 16 (mean = 6.5, standard deviation = 3.4). CBCT was performed for all patients, and an extracted tooth covered with self-cured acrylic resin was used as a radiographic density calibration tool. The gray values of the enamel, coronal and radical dentine regions of all the teeth were measured by two examiners. The average values of enamel and dentine radiographic density of incisors, canines, premolars and molars in each jaw and both jaws were calculated, and correlated with DMFT.

Results: The radiographic density of mandibular incisors and all incisors of both jaws had the highest Pearson correlation coefficients with DMFT (0.33 < r < 0.42, P-value = 0.016). Neither the coronal nor the radicular dentine radiographic density was correlated with the DMFT according to any examiner.

Conclusion: Enamel, not dentine, radiographic density calculated from incisors via CBCT scans was correlated with DMFT in individuals aged > 20 to 25 years. The strengths of these correlations were moderate.

Clinical relevance: The enamel radiographic density of incisors, measured by CBCT using a novel calibration tool, was correlated with dental caries status in young adults aged 20-25 years. Thus, this study provides deeper insight into the radiographic density of dental hard tissues as a determinant of dental caries. This factor is also measurable in a clinical setting.

Keywords: Cone beam computed tomography; DMFT; Dental caries; Dentine; Enamel; Radiographic density.

Fig. 1

The extracted tooth, used for calibration, was covered with pink self-cured acrylic resin in the root and translucent acrylic resin in the crown

Fig. 2

Angulation adjustment. Sagittal and coronal cursors on all windows were made parallel to the long axis of an anterior (A) and a posterior tooth (B)

Fig. 3

Studying the tooth in the axial plane. The axial slice lies just to the occlusal direction from the pulp chamber for an anterior (A) and a posterior tooth (B). The radiographic density of the coronal dentine was calculated for the anterior (C) and posterior (D) teeth

Fig. 4

Calculating the radiographic density in the sagittal plane. (A) The main sagittal slice identified for an anterior tooth. The radiographic density of the enamel and dentine in the crown of an anterior (B) and a posterior tooth (C) was calculated

Fig. 5

Calculating the radiographic density in the coronal plane. (A) Note that all the cursors in all the windows passed through the correct location for studying the radiographic density so that they were within the enamel and dentine. The radiographic density of the enamel and dentine in the frontal plane for an anterior tooth (B) and a posterior tooth (C) was studied

Fig. 6

Calculating the radiographic density of the radicular dentine. The radiographic density of the dentine in the root away from the radicular canal was calculated on the axial slice for an anterior (A) and a posterior tooth (B). (C) Ensuring that the cursors pass through the radicular dentine in all windows. The radiographic density of the radicular dentine on the sagittal slice was calculated for an anterior (D) and a posterior tooth (E). The radiographic density of the radicular dentine on the coronal slice was calculated for an anterior (F) and a posterior tooth (G)

Fig. 7

Calculating the radiographic density of the extracted tooth. (A) Angulation adjustment so that two of the three cursors pass parallel to the long axis of the tooth. The radiographic density of the enamel and dentine in the crown of the tooth on the axial (B) and sagittal (C) slices windows was calculated. The radiographic density of the radicular dentine on the coronal slices window (D) was calculated to ensure that the location was one slice apical to the pulp chamber as shown from other windows (E)

Fig. 8

Calculating the radiographic density for the trabecular bone alone and for both the cortical and trabecular bone at the angle of the mandible. (A) Angulation adjustment so that the sagittal cursor is parallel to the buccal and lingual cortices of the mandible. (B) Tracing the inferior mandibular canal. (C) Calculating the radiographic density for the trabecular bone alone and for both the cortical and trabecular bone on the sagittal slice