NBE Sciences case studies
NBE Sciences · Put your knowledge to work in context.
The NBE Sciences exam is a discipline-based written assessment used in dental education and licensure pathways. It tests foundational biomedical science rather than clinical technique: general biology, general and organic chemistry, physics, anatomy, physiology, pathology, microbiology, and a smaller dental materials component. The NBE Sciences case studies are 5 cases and about 3,034 words.
1Betacyanin Leakage from Beetroot Tissue: Interpreting a Membrane Integrity Assay
In a lab practical, 1 cm³ cubes are cut from a fresh beetroot, rinsed in distilled water until the rinse is colorless, blotted, and placed in tubes. Each tube contains 10 mL of one of the following: distilled water at 20 °C, 40 °C, 50 °C, 60 °C, or 70 °C; or 20%, 40%, or 60% ethanol at 20 °C.
630 words, about 3 min2Preparing a Phosphate Buffer for a Temperature-Sensitive Enzyme Assay
A research assistant must prepare 500 mL of 0.10 M sodium phosphate buffer at pH 7.40 for an enzyme assay. The laboratory has solid NaH2PO4 (MW 119.98) and Na2HPO4 (MW 141.96); the second dissociation pKa is 7.20 at 25 °C.
636 words, about 3 min3Curing-Light Dose in a Deep Class II Composite Restoration
A dentist is restoring a 4 mm deep Class II cavity in a mandibular molar with a light-cured composite. The LED curing unit has an 8 mm diameter light guide and the manufacturer states an irradiance of 1,200 mW/cm² at the tip.
628 words, about 3 min4Lower Lip Numbness After Surgical Removal of an Impacted Third Molar
A 29-year-old woman undergoes surgical extraction of an impacted mandibular right third molar (tooth 38). The crown is at the cervical level of the adjacent second molar, and a CBCT shows the root apices overlapping the mandibular canal, with no visible cortical bone between the root apex and the canal.
564 words, about 3 min5Recurrent Caries and Sensitivity at a Deep Composite Margin
A 45-year-old man has a large MOD composite restoration on tooth 46 placed three years ago. He now has recurrent caries at the gingival margin, marginal staining, and cold sensitivity.
576 words, about 3 min