(1) Background: The treatment of dental cavities and restoration of tooth shape requires specialized materials with specific clinical properties, including being easy to model, light-cured, having a natural color, reduced shrinkage, a hardness similar to hydroxyapatite, and no leakage. The dimensional stability of resin composite materials is affected by polymerization shrinkage, degree of conversion (number of π carbon bonds converted into σ ones), thermal contraction and expansion, and interactions with an aqueous environment. (2) Methods: The materials used in our investigation were two composite resins with similar polymer matrices, but different filler (micro/nano filler). To evaluate the properties of samples, we employed the pycnometer technique (pycnometer from Paul Marienfeld Gmbh, Lauda-Königshofen, Germany), RAMAN spectroscopy technique (MiniRam Equipment from B&W Tek Inc., Plainsboro Township, NJ, USA; 785 nm laser source), SEM and EDX (FEI Inspect S.). (3) Results: The size of the filler plays an important role in the polymerization: for the pycnometric results, the larger particle filler (Sample 1) seems to undergo a rapid polymerization during the 45 s curing, while the nanoparticle filer (Sample 2) needs additional curing time to fully polymerize. This is related to a much larger porosity, as proved by SEM images. The lower degree of conversion, as obtained by Raman spectroscopy, in the same geometry means that the same volume is probed for both samples, but Sample 1 is more porous, which means less amount of polymer is probed for Sample 1. (4) Conclusions: For the two composites, we obtained a degree of conversion of 59% for Sample 1 and 93% for Sample 2, after 45 s of curing.

The aim of this study was to evaluate the quality of the bone, revealing the different phases for calcified tissues independent of the medical history of the patient in relation to periodontitis by means of in vivo Raman spectroscopy. Raman spectroscopy measurements were performed in vivo during surgery and then ex vivo for the harvested bone samples for the whole group of patients (ten patients). The specific peaks for the Raman spectrum were traced for reference compounds (e.g., calcium phosphates) and bone samples. The variation in the intensity of the spectrum in relation to the specific bone constituents’ concentrations reflects the bone quality and can be strongly related with patient medical status (before dental surgery and after a healing period). Moreover, bone sample fluorescence is related to collagen content, enabling a complete evaluation of bone quality including a “quasi-quantification” of the healing process similar to the bone augmentation procedure. A complete evaluation of the processed spectra offers quantitative/qualitative information on the condition of the bone tissue. We conclude that Raman spectroscopy can be considered a viable investigation method for an in vivo and quick bone quality assessment during oral and periodontal surgery.

This contribution takes in account investigation of dental enamel regarding “quality” of hydroxyapatite material involved in the mineralization process. Areas damaged by black stain were investigated in order to evaluate changes in chemical composition as compared to those of healthy dental enamel. Different sectors on tooth surfaces were analyzed using micro-Raman spectroscopy. The integral areas of ν₁ (960 cm⁻¹) phosphate peak as well as of B-type carbonate peak ν₂ (1070 cm⁻¹) were obtained to investigate structural differences between the specimens (healthy/unhealthy enamel tooth and different sectors on unhealthy surface tooth). A complete list of chemical specimens involved in chemical processes on dental enamel surface was obtained by Energy Dispersive x-rays (EDX) investigation. It was noticed that mineralized carbonate peak at 1070 cm⁻¹ decreased significantly for unhealthy tooth enamel or spots areas (as fluorite groups), suggesting that carbonate ions are easily dissolved in the presence of fluoride. The present study is confirming an organic origin for the dental “black stain.” The “black stain” is the result of a complex generation process from the damaged enamel, thus explaining their reappearance after the mechanical removing. A possible model for the “black stain” generation process is advanced.

(1) Background: In oral surgery, bone regeneration is achieved through various types of bone grafts or bone substitutes and its success is usually analyzed by micro-computed tomography and histomorphometry. The aim of this study was to evaluate the usefulness of Raman spectroscopy as an alternative to other techniques for bone quality evaluation during a standard oral surgery procedure. (2) Methods: The preliminary evaluation of bone augmentation during maxillary sinus floor elevation oral surgery was performed by Raman spectroscopy for several (five) patients during and after the surgery and the results were compared with postoperative data from histomorphometry, EDX and SEM analysis. (3) Results: After analyzing all the results for the bone samples according to the four methods (Raman, EDX, SEM and Histology) that were used in our study, the obtained result of the investigation provided a good augmentation process for three of the patients and partly successful augmentation process for two of the patients. The primary evaluation using Raman spectroscopy (in vivo and ex vivo investigation) was confirmed by histological results, thus having a first step for validation of Raman as a new method of imaging for dentistry. (4) Conclusions: Our results show that Raman spectroscopy could provide fast and reliable insight on bone condition during augmentation of the maxillary sinus floor. We emphasize the advantages and drawbacks of the proposed techniques as its accuracy could increase by performing larger size clinical trials. Using the Raman mapping, the method can serve as an alternative to histology.