Radiopacity of resin-based CAD/CAM blocks assessed by areal grayscale pixel value measurement.

PURPOSE: This study assessed radiopacity of resin-based computer-aided-design/computer-aided-manufacturing (CAD/CAM) materials by areal grayscale pixel value measurement. METHODS: Radiopacities of six resin-based CAD/CAM block materials and resin composite were evaluated and compared to that of enamel and dentin. Specimens of 1-mm thickness were placed on photostimulable phosphor plate and irradiated with digital x-ray unit. On the radiographic image, regions of interests were determined for each specimen and areal grayscale pixel values were measured. Elemental analysis was performed with energy-dispersive x-ray spectroscopy (EDS) on field emission scanning electron microscope (FESEM) images of the specimens. Data were analyzed statistically (α = 0.05). RESULTS: Radiopacity values of the restorative materials were significantly different from each other (P < 0.05). Radiopacity values of two resin-based CAD/CAM materials were significantly lower than that of dentin (P < 0.05). All tested restorative materials contain zirconium, three materials contain barium, and only resin composite contains lanthanum. CONCLUSION: Four CAD/CAM materials with higher amounts of zirconia or barium (>18%) had radiopacity values significantly higher than the dentin; while two materials with lower amounts of zirconia (<4%) and/or no-barium, had radiopacity values significantly lower than the dentin. EDS analysis suggests materials containing elements with higher atom numbers such as zirconia and barium could exhibit higher radiopacity.

Corticosteroid injection in treatment of persistent oral lichen planus: Three cases.

Oral lichen planus (OLP) is a chronic inflammatory disease with unknown etiology. There are many clinical types of OLP. OLP cases are often asymptomatic; however, atrophic or erosive forms may cause sensitivity, burning, and discomfort. The best model of the OLP treatment modality is to evaluate the restorations that may lead to oral mucosa hypersensitivity as the first step. Local corticosteroid injection therapy may be preferred to eliminate the possible systemic side effects of systemic corticosteroid medication in patients with OLP. The aim of this case series is to evaluate treatment alternatives in OLP.

Evaluation of genial tubercle anatomy using cone beam computed tomography.

The purpose of this study was to characterize the anatomy of the genial tubercle using cone beam computed tomography (CBCT). The morphology and detailed anatomy of the genial tubercle were assessed retrospectively in 201 patients (101 females, 100 males) using CBCT images. The parameters examined were the height (GH) and width (GW) of the genial tubercle, the distance from the lower incisors to the superior border of the tubercle (I-SGT), the distance from the inferior margin of the tubercle to the inferior margin of the mandible (IGM-IBM), and the anterior mandible thickness (AMT). Statistical analysis was performed to assess relationships among these parameters, gender, and orthodontic malocclusion (P < 0.05). The values obtained were GH 7.3-8.7 mm, GW 7.9-9.2 mm, I-SGT 7.1-9.1 mm, IGM-IBM 8.3-10.1 mm, and AMT 14.0-16.2 mm. GH, GW, and I-SGT showed no significant differences between genders (P > 0.05). However, IGM-IBM was larger for class III than for class I and class II male patients, and larger than for class I female patients. AMT in class III patients was greater than in class I and II patients (P < 0.05). The use of CBCT, which employs less radiation, is important for dental professionals, especially those performing surgery for obstructive sleep apnea (OSA), in order to avoid possible surgical complications.