Odontogenic facial swelling of unknown origin

BACKGROUND: Current radiography techniques have limitations in detecting subtle odontogenic anomalies or defects that can lead to dentoalveolar and facial infections. This report examines the application of micro-CT imaging on two extracted teeth to enable detailed visualization of subtle odontogenic defects that had given rise to facial swellings. METHODS: Two extracted non-carious mandibular left primary canine teeth (73) associated with odontogenic infections were selected from healthy patients, and an intact contralateral tooth (83) from one of the patients was used as a control. All three teeth were subjected to the three-dimensional micro-CT imaging at a resolution of 20 μm. RESULTS: Tooth 73 from the first case displayed dentine pores (channels) that established communication between the pulp chamber and the exposed dentine surface. In comparison, tooth 73 from the second case had a major longitudinal crack extending from the external enamel surface into the pulp chamber. The control tooth did not display any anomalies or major cracks. CONCLUSIONS: The scope of micro-CT imaging can be extended from current in vitro applications to establish post-extraction diagnosis of subtle odontogenic defects, in a manner similar to confirming histopathological diagnoses in extracted teeth. Ongoing technological advancements hold the promise for more widespread translatory applications.S Ranjitkar, W Cheung, R Yong, J Deverell, M Packianathan, C Hal

3D printed titanium micro-bore columns containing polymer monoliths for reversed-phase liquid chromatography

The potential of 3D selective laser melting (SLM) technology to produce compact, temperature and pressure stable titanium alloy chromatographic columns is explored. A micro bore channel (0.9 mm I.D. × 600 mm long) was produced within a 5 × 30 × 30 mm titanium alloy (Ti-6Al-4V) cuboid, in form of a double handed spiral. A poly(butyl methacrylate-co-ethyleneglycoldimethacrylate) (BuMA-co-EDMA) monolithic stationary phase was thermally polymerised within the channel for application in reversed-phase high-performance liquid chromatography. The prepared monolithic column was applied to the liquid chromatographic separation of intact proteins and peptides. Peak capacities of 69-76 (for 6-8 proteins respectively) were observed during isothermal separation of proteins at 44 °C which were further increased to 73-77 using a thermal step gradient with programmed temperature from 60 °C to 35 °C using an in-house built direct-contact heater/cooler platform based upon matching sized Peltier thermoelectric modules. Rapid temperature gradients were possible due to direct-contact between the planar metal column and the Peltier module, and the high thermal conductivity of the titanium column as compared to a similar stainless steel printed column. The separation of peptides released from a digestion of E.coli was also achieved in less than 35 min with ca. 40 distinguishable peaks at 210 nm