Modern dentistry is turning towards natural sources to overcome the immunological, toxicological, aesthetic, and durability drawbacks of synthetic materials. Among the first biomaterials used as endosseous dental implants, mollusk shells also display unique features, such as high mechanical strength, superior toughness, hierarchical architecture, and layered, microporous structure. This review focusses on hydroxyapatite—a bioactive, osteoconductive, calcium-based material crucial for bone healing and regeneration. Mollusk-derived hydroxyapatite is widely available, cost-effective, sustainable, and a low-impact biomaterial. Thermal treatment coupled with wet chemical precipitation and hydrothermal synthesis are the most common methods used for its recovery since they provide efficiency, scalability, and the ability to produce highly crystalline and pure resulting materials. Several factors, such as temperature, pH, and sintering parameters, modulate the size, purity, and crystallinity of the final product. Experimental and clinical data support that mollusk shell-derived hydroxyapatite and its carbonated derivatives, especially their nanocrystaline forms, display notable bioactivity, osteoconductivity, and osteoinductivity without causing adverse immune reactions. These biomaterials are therefore highly relevant for specific dental applications, such as bone graft substitutes or dental implant coatings. However, continued research and clinical validation is needed to optimize the synthesis of mollusk shell-derived hydroxyapatite and determine its applicability to regenerative dentistry and beyond.

Background: The prevalence of dental caries has increased among children, largely due to nutritional habits or inadequate access to dental care. The present study aimed to investigate the prevalence of dental caries associated with various factors that lead to their appearance, such as food intake and body composition, among Romanian school-age children from two counties, Bistriţa Năsăud and Mureş. Methods: This cross-sectional study included 1100 children aged 6–10 years from two Romanian counties. Dental caries experience was assessed using the DMFT and dmft indices based on WHO criteria. Dietary intake and oral health behaviors were evaluated through a food frequency questionnaire completed by parents. Associations between dietary variables and dental caries were assessed using independent sample t-tests and Mann–Whitney U tests. A binary logistic regression model was used to estimate the likelihood of caries in the permanent dentition (DMFT > 0), with covariates including county, parental education, daily sugar intake, consumption of dairy products, body mass index (BMI), and waist-to-height ratio. Results: It was found that the children who daily consume cheese recorded a DMFT value lower than the children who did not consume (p < 0.05). Moreover, those who consume sugary foods recorded higher values of DMFT as compared with those who did not (p < 0.05). The body weight, BMI, and waist circumference are positively correlated with DMFT, but negatively with dmft (p < 0.05). The overall prevalence of caries was 79.8% in primary dentition and 63.6% in permanent dentition, with slightly higher rates observed in Bistriţa-Năsăud County compared to Mureş. It seems that the predictors of the caries’s presence among children include the mother’s education level, sugar intake frequency, and body fat ratio. Conclusions: Based on significant associations found, one can affirm that the dental caries of the Romanian school-age children is due to sugary food intake and body composition. In addition, the direct relationship between dental caries and childhood obesity showed through the correlation of BMI and dental health indices denotes that school-age children should reduce sugary foods and increase dairy products.

The evaluation of chlorhexidine-carrier nanosystems based on iron oxide magnetic nanoparticles (IOMNPs), has gained significant attention in recent years due to the unique properties of the magnetic nanoparticles (NPSs). Chlorhexidine (CHX), a well-established antimicrobial agent, has been widely used in medical applications, including oral hygiene and surgical antisepsis. This study aims to report an in vitro and in ovo toxicological screening of the synthesized CHX-NPS nanosystem, of the carrier matrix (maghemite NPSs) and of the drug to be delivered (CHX solution), by employing two types of cell lines—HaCaT immortalized human keratinocytes and JB6 Cl 41-5a murine epidermal cells. After the characterization of the CHX-NPS nanosystem through infrared spectroscopy and electronic microscopy, the in vitro results showed that the CHX antimicrobial efficacy was enhanced when delivered through a nanoscale system, with improved bioavailability and reduced toxicity when this was tested as the newly CHX-NPS nanosystem. The in ovo screening exhibited that the CHX-NPS nanosystem did not cause any sign of irritation on the chorioallantoic membrane vasculature and was classified as a non-irritant substance. Despite this, future research should focus on optimizing this type of nanosystem and conducting comprehensive in vivo studies to validate its therapeutic efficacy and safety in clinical settings.