Could Low-dose Cone-beam CT be Used for Endodontic Intraoperative Diagnosis?

INTRODUCTION: Cone-beam computed tomography (CBCT) allows three-dimensional evaluation and has high diagnostic accuracy of endodontic conditions. Considering that the most indicated protocol for endodontics should have smaller field-of-view and higher spatial resolution, a higher radiation dose may be associated. Thus, this study evaluated the accuracy of an optimized CBCT protocol for the detection of intraoperative endodontic complications. METHODS: An image phantom was custom-made with a human mandible covered with Mix-D and forty mandibular first molars. The teeth were subdivided into 4 groups of endodontic complications which were simulated. All teeth were individually inserted into the left second molar socket of the phantom and CBCT images were acquired with OP 300 unit adjusted to a field-of-view of 6 × 4 cm, 90kVp, and 2 dose protocols: low and high. Furthermore, a titanium implant, a tooth with endodontic treatment, and a cobalt-chromium post were inserted into the empty sockets adjacent to the teeth of interest and additional images were acquired. Four endodontists evaluated the images and indicated the presence of endodontic complications on a 5-point scale. Sensitivity, specificity, and area under the receiver operating characteristic curve were obtained. The different groups were compared by ANOVA and Tukey tests (α = 0.05). RESULTS: In most conditions, irrespective of the presence of metallic materials, the values of accuracy, sensitivity, specificity, and area under the receiver operating characteristic curve did not differ significantly (P > .05) between the dose protocols. CONCLUSIONS: Optimized CBCT protocols should be considered for the detection of intraoperative endodontic Diagnostic complications.

Integrated review of resource recovery on aerobic granular sludge systems: Possibilities and challenges for the application of the biorefinery concept.

Aerobic Granular Sludge (AGS) is a biological treatment technology that has been extensively studied in the last decade. The possibility of resource recovery has always been highlighted in these systems, but real-scale applications are still scarce. Therefore, this paper aimed to present a systematic review of resources recovery such as water, energy, chemicals, raw materials, and nutrients from AGS systems, also analyzing aspects of engineering and economic viability. In the solid phase, sludge application in agriculture is an interesting possibility. However, the biosolids' metal concentration (the granules have high adsorption capacity due to the high concentration of extracellular polymeric substances, EPS) may be an issue. Another possibility is the recovery of Polyhydroxyalkanoates (PHAs) and Alginate-like exopolymers (bio-ALE) in the solid phase, emphasizing the last one, which has already been made in some Wastewater Treatment Plants (WWTPs), named and patented as Kaumera® process. The Operational Expenditure (OPEX) can be reduced by 50% in the WWTP when recovery of ALE is made. The ALE recovery reduced sludge yield by up to 35%, less CO2 emissions, and energy saving. Finally, the discharged sludge can also be evaluated to be used for energetic purposes via anaerobic digestion (AD) or combustion. However, the AD route has faced difficulties due to the low biodegradability of aerobic granules.