The objective of the Colgate-Palmolive project is to characterize the organic content and its distribution at the crystalline level in human enamel. This includes determining the distribution of proteins throughout the enamel, distinguishing the differences in composition between young and old adult teeth, and analyzing how protein composition impacts the mechanical properties of enamel within the context of aging. Raman spectroscopy was conducted to analyze the mineral composition of enamels following KOH or NaOCl deproteinization treatments, with control conditions used to isolate the impacts of protein on enamel properties. Additionally, Vickers indentation was conducted to analyze the mechanical properties of enamel following each treatment, with respect to the distance between enamel surface and the dentin enamel junction. These techniques jointly characterized the distribution of proteins within dental enamel and how it impacts mechanical behavior. 

Concrete is the most widely used structural material globally due to its strength and durability, with demand steadily increasing. Ordinary Portland cement (OPC) is the primary binder in cementitious materials and participates in hydration reactions that contribute to the compressive strength. Unfortunately, the production of cement is responsible for ~8% of global CO₂ emissions, driving efforts to reduce its use in concrete and other cementitious materials. Consequently, supplementary cementitious materials (SCMs), such as zeolite, are being explored to reduce, but not entirely eliminate, cement in industrial settings. Zeolite is a naturally-occurring microporous pozzolanic mineral that has the propensity for replacing cement through strengthening and densifying mechanisms. It also has capability for carbon capture, which can contribute to further reduction of atmospheric CO₂. However, the effect of zeolite on carbonation reactions in concrete is not well characterized. Pozzolanic and carbonation reactions can synergize to cause concrete and mortar (concrete sans large aggregates) to further densify and strengthen over time, but they compete for the use of calcium hydroxide, a hydration byproduct. This research investigates the effect of replacing up to 30% cement in concrete with natural zeolite on the carbonation of mortar composites over a curing period of 28 days. Carbonation is conducted through elevated pressure and CO₂ concentration, rather than ambient pressure. The effect of zeolite is measured using microCT for porosity analysis, compressive testing for strength, and pH indication of cross-sections for carbonation depth. Results indicate that the porosity decreases while carbonation depth increases with zeolite content. The zeolite addition contributes to the reduction of compressive strength, ranging from 71.6 to 37.7 MPa. Overall, carbonation enhances strength, correlating with carbonation depth, but this trend is more evident under ambient carbonation (2.78% strength increase after four weeks) than under pressurized carbonation, where no distinct trend is observed.

Tooth whitening is a rapidly growing sector in oral health, yet the interactions between chemical whitening products and the tooth microstructure remain complex and not fully understood. This study investigates how natural changes in the enamel microstructure and composition with age affect tooth whitening efficacy. Specifically, we are looking at the enamel of teeth from different age groups that are treated with the whitening agents potassium hydroxide (KOH) and bleach (NaOCl). Using Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy, we assess key compositional parameters, including organic-mineral ratios and carbonate-phosphate ratios, as both techniques reveal characteristic spectral “fingerprints” of enamel. Preliminary results indicate observable changes in the molecular structure of enamel post-treatment, emphasizing the need for balancing product efficacy with enamel preservation. This research not only advances tooth whitening technologies but also contributes to broader dental care practices for a range of ages, ensuring safer and more effective dental products for consumers.