Considerable resources are expended in dealing with dental disease easily prevented with better oral hygiene. The study hypothesis was that an evidence-based intervention, framed with psychological theory, would improve patients' oral hygiene behavior. The impact of trial methodology on trial outcomes was also explored by the conducting of two independent trials, one randomized by patient and one by dentist. The study included 87 dental practices and 778 patients (Patient RCT = 37 dentists/300 patients; Cluster RCT = 50 dentists/478 patients). Controlled for baseline differences, pooled results showed that patients who experienced the intervention had better behavioral (timing, duration, method), cognitive (confidence, planning), and clinical (plaque, gingival bleeding) outcomes. However, clinical outcomes were significantly better only in the Cluster RCT, suggesting that the impact of trial design on results needs to be further explored.

Epidemiological studies suggest that a single moderate-to-severe traumatic brain injury (TBI) is associated with an increased risk of neurodegenerative disease, including Alzheimer's disease (AD) and Parkinson's disease (PD). Histopathological studies describe complex neurodegenerative pathologies in individuals exposed to single moderate-to-severe TBI or repetitive mild TBI, including chronic traumatic encephalopathy (CTE). However, the clinicopathological links between TBI and post-traumatic neurodegenerative diseases such as AD, PD, and CTE remain poorly understood. Here, we describe the methodology of the Late Effects of TBI (LETBI) study, whose goals are to characterize chronic post-traumatic neuropathology and to identify in vivo biomarkers of post-traumatic neurodegeneration. LETBI participants undergo extensive clinical evaluation using National Institutes of Health TBI Common Data Elements, proteomic and genomic analysis, structural and functional magnetic resonance imaging (MRI), and prospective consent for brain donation. Selected brain specimens undergo ultra-high resolution ex vivo MRI and histopathological evaluation including whole-mount analysis. Co-registration of ex vivo and in vivo MRI data enables identification of ex vivo lesions that were present during life. In vivo signatures of postmortem pathology are then correlated with cognitive and behavioral data to characterize the clinical phenotype(s) associated with pathological brain lesions. We illustrate the study methods and demonstrate proof of concept for this approach by reporting results from the first LETBI participant, who despite the presence of multiple in vivo and ex vivo pathoanatomic lesions had normal cognition and was functionally independent until her mid-80s. The LETBI project represents a multidisciplinary effort to characterize post-traumatic neuropathology and identify in vivo signatures of postmortem pathology in a prospective study.