Space Maintainers Used in Pediatric Dentistry: An Insight of Their Biosecurity Profile by Applying In Vitro Methods

Effectiveness of traditional band and loop space maintainer vs 3D-printed space maintainer following the loss of primary teeth: a randomized clinical trial

This study evaluates the efficacy of 3D-printed band and loop space maintainers (3D-BLSMs) to mitigate concerns caused by early primary tooth loss in children when compared to their conventional equivalents. Over 9 months, 62 participants aged 6 to 12 years participated in a randomized clinical study. This study evaluated their failure rates (de-cementation, debonding, solder breakage, loop breakage, band breakage, and abutment tooth fracture), gingival health, and patient overall satisfaction. Random assignments were made to place the participants in two groups: traditional band and loop space maintainers or the 3D-BLSMs. The findings show that at 9 months, 3D-BLSMs provided significantly higher survival rates (77.4%) than conventional maintainers (51.6%, p < 0.01). Gum inflammation was mild in both groups, highlighting the need for good oral hygiene. In both groups, patient satisfaction exceeded 90%. Although there was some pain at first with 3D-BLSMs, this eventually subsided and aesthetic preferences disappeared. There were no negative consequences noted, and both groups needed ongoing dental treatment. In conclusion, with excellent patient satisfaction in both groups, 3D-printed space maintainers offer greater long-term durability in reducing dental concerns following early primary tooth loss.

A Preliminary Report Regarding the Morphological Changes of Nano-Enabled Pharmaceutical Formulation on Human Lung Carcinoma Monolayer and 3D Bronchial Microtissue

Background and Objectives: Nowadays, the development of enabled pharmaceutical nanoparticles of solid lipid type is continuously growing, because they have the potential to be used for targeted drug release leading to an increased effect of chemotherapy, being used in lung cancer nano-diagnosis and nano-therapy. The current study reports the preliminary results obtained regarding the biological effect of a new nano-enabled pharmaceutical formulation in terms of its cytotoxic and biosafety profile. Materials and Methods: The pharmaceutical formulations consist of solid lipid nanoparticles (SLN) obtained via the emulsification-diffusion method by loading green iron oxide nanoparticles (green-IONPs) with a pentacyclic triterpene (oleanolic acid-OA). Further, a complex biological assessment was performed, employing three-dimensional (3D) bronchial microtissues (EpiAirwayTM) to determine the biosafety profile of the SLN samples. The cytotoxic potential of the samples was evaluated on human lung carcinoma, using an in vitro model (A549 human lung carcinoma monolayer). Results: The data revealed that the A549 cell line was strongly affected after treatment with SLN samples, especially those that contained OA-loaded green-IONPs obtained with Ocimum basilicum extract (under 30% viability rates). The biosafety profile investigation of the 3D normal in vitro bronchial model showed that all the SLN samples negatively affected the viability of the bronchial microtissues (below 50%). As regards the morphological changes, all the samples induce major changes such as loss of the surface epithelium integrity, loss of epithelial junctions, loss of cilia, hyperkeratosis, and cell death caused by apoptosis. Conclusions: In summary, the culprit for the negative impact on viability and morphology of 3D normal bronchial microtissues could be the too-high dose (500 µg/mL) of the SLN sample used. Nevertheless, further adjustments in the SLN synthesis process and another complex in vitro evaluation will be considered for future research.

In vitro examination of fracture resistance of 3D-printed resin blocks in different diameters

Objectives:

The intraoral use of commercial printable polymers in dental patients is still a challenge due to the unknown physical properties of the materials. The present study aimed to comparably evaluate the maximum load and deflection values of three-dimensional-printed resin blocks in different diameters that can be used intraorally in dental patients.

Material and Methods:

Forty-five cylindrical resin blocks in diameters of 2 mm (Group 1, n = 15), 3 mm (Group 2, n = 15), and 4 mm (Group 3, n = 15) and lengths of 20 mm were designed and printed. The samples were placed in the universal testing device to conduct the 3-point bending test. According to the Shapiro–Wilk normality test results, Kruskal–Wallis and Mann–Whitney U tests were performed for the statistical analysis. The level of statistical significance was accepted as P < 0.05.

Results:

The values for the maximum load (N) and deflection (mm) in the study groups were 218.4 ± 31.9, 2.96 ± 0.86 in Group 3; 77.05 ± 61.5, 3.91 ± 0.92 in Group 2; and 19.67 ± 2.63, 4.06 ± 1.02 in Group 1, respectively. The mean values of maximum load for Group 3 were superior to Group 2 (P = 0.020) and Group 1 (P = 0.00). Group 2 revealed higher maximum load results than Group 1 (P = 0.003). The mean values of maximum deflection in Group 3 were lower compared to Group 2 (P = 0.014) and Group 1 (P = 005).

Conclusion:

The results of this in vitro study encourage the use of resin-printed intraoral appliances in place of conventional treatment modalities.