Enhancing the Therapeutic Potential of Mesenchymal Stem Cells with Light-Emitting Diode: Implications and Molecular Mechanisms.

This study evaluated the effects of light-emitting diode (LED) on mesenchymal stem cells (MSCs). An electronic search was conducted in PubMed/MEDLINE, Scopus, and Web of Science database for articles published from 1980 to February 2020. Ten articles met the search criteria and were included in this review. The risk of bias was evaluated to report quality, safety, and environmental standards. MSCs were derived from adipose tissue, bone marrow, dental pulp, gingiva, and umbilical cord. Protocols for cellular irradiation used red and blue light spectrum with variations of the parameters. The LED has been shown to induce greater cellular viability, proliferation, differentiation, and secretion of growth factors. The set of information available leads to proposing a complex signaling cascade for the action of photobiomodulation, including angiogenic factors, singlet oxygen, mitogen-activated protein kinase/extracellular signal-regulated protein kinase, Janus kinase/signal transducer, and reactive oxygen species. In conclusion, although our results suggest that LED can boost MSCs, a nonuniformity in the experimental protocol, bias, and the limited number of studies reduces the power of systematic review. Further research is essential to find the optimal LED irradiation parameters to boost MSCs function and evaluate its impact in the clinical setting.

Evaluation of cervico-occlusal dimensions of maxillary and mandibular incisor brackets for lingual orthodontics.

AIM: The purpose of this study was to analyze the cervico-occlusal dimensions of brackets used in lingual orthodontics for maxillary and mandibular central and lateral incisors, to compare them with the numbers informed by the manufacturer. MATERIALS AND METHODS: The brackets were placed in a template and analyzed by scanning electron microscopy (SEM), evaluating the images with the aid of a software that allowed determination of reference points, tracing of lines on the bracket images and measurement of the distances. RESULTS: Brackets manufactured by Dm Ceosa Hiro, Tecnident PSWb and Dentaurum Magic did not present statistically significant differences between the mean values of slot heights and the values informed by manufacturers. Conversely, the brands Ormco 7th generation, Ormco STb, GAC Innovation L, ORJ-ORG, Tecnident, Ormco STb LSW and Adenta evolution STL exhibited statistically significant differences. CONCLUSION: In general, there was a deficiency in the standar-dization of cervico-occlusal measurements of slots of the brackets analyzed. CLINICAL SIGNIFICANCE: Manufacturers should be attentive to the quality control of their materials. Future studies will analyze the actual clinical influence of these findings on the orthodontic mechanics.