INFLUENCE OF STORAGE MEDIA ON THE VITALITY OF STEM CELLS FROM APICAL PAPILLA

Purpose: Immediate replantation is the treatment of choice for avulsed permanent teeth. Transportation of avulsed teeth to the dentist office requires storage in suitable media, thus keeping periodontal and periapical tissues viable. Effect of different storage media on periodontal cells vitality has been thoroughly researched, but there is no available data concerning SCAP. The purpose of this study is to evaluate the storage media effect on SCAP vitality. Materials and methods: Our study includes 10 third molars of 14-17 years old patients, extracted due to orthodontic reasons. The apical papilla of those teeth is handled according to protocol, and the cell growth is maintained in DMEM. Cells are divided into 4 groups: 1-positive control group, 2- SOS Dentobox, 3 - (HBSS), 4 - negative control group. A colourimetric assay was used to determine the vital cell count in each group. Results: Signal strength of the cells, stored in SOS Dentobox, is on average 30% weaker than the positive control group cells’ signal, while the signal strength of the cells, stored in HBSS, is 65,2% weaker. Conclusion: SOS Dentobox provides better SCAP cell vitality than HBS

Comparative Analysis of Root Dentin Loss when Using Modern Mechanical Cleaning Instruments in Immature Permanent Teeth

Introduction: The full decontamination and disinfection of the root canal system is essential for the success of regenerative endodontic procedures. The current literature does not have information regarding mechanical cleaning of immature teeth with contemporary endodontic instuments.Aim: To compare the thickness and volume of the dentin removed from the roots of immature teeth after endodontic preparation using XP-endo Finisher, GentleFile Brush and a standard H-file scraping technique through micro-computed tomography.Methods: The study included 51 immature permanent molars. Endodontic access was prepared and without performing preliminary extirpation of the pulp, the teeth were divided into three groups. The first group of teeth were instrumented for two minutes with XP-endo Finisher, the second - two minutes with Gentlefile Brush, in the third group the root canals walls were scraped with a No. 40 H-file. The thickness and the volume of the removed dentin was assessed using micro-CT imaging before and after the use of the instruments.Results: There is no statistically significant difference in the mean values of thickness of dentin removed between the teeth, prepared with XP-endo finisher and Gentlefile Brush. When comparing the mean values of volume of dentin removed between the separate groups, a statistically significant difference was discovered for every compared pair with the highest volume of removed dentin in the group prepared with a hand instrument.Conclusion: The endodontic systems tested when used in immature permanent teeth remove significantly less quantity of hard dental structures compared to a hand file for scraping the root canal

Point-of-care biosensor systems for cancer diagnostics/prognostics

Polymeric nanoparticles have been introduced as a delivery vehicle for active compounds in a broad range of medical applications due to their biocompatibility, stability, controlled release of active compounds, and reduced toxicity. The oral route is the most used approach for delivery of biologics to the body. The homeostasis and function of oral cavity tissues are dependent on the activity of stem cells. The present work focuses, for the first time, on the interaction between two types of polymeric nanoparticles, poly (lactic-co-glycolic acid) or PLGA and PLGA/chitosan, and two stem cell populations, oral keratinocyte stem cells (OKSCs) and stem cells from human exfoliated deciduous teeth (SHEDs). The main results show that statistical significance was observed in OKSCs uptake when compared with normal keratinocytes and transit amplifying cells after 24 h of incubation with 5 and 10 µg/mL PLGA/chitosan. The CD117 SHED subpopulation incorporated more PLGA/chitosan nanoparticles than nonseparated SHED. The uptake for PLGA/chitosan particles was better than for PLGA particles with longer incubation times, yielding better results in both cell types. The present results demonstrate that nanoparticle uptake depends on stem cell type, incubation time, particle concentration, and surface properties

From Normal Skin to Squamous Cell Carcinoma: A Quest for Novel Biomarkers

Squamous cells carcinoma (SCC) is the second most frequent of the keratinocyte-derived malignancies after basal cell carcinoma and is associated with a significant psychosocial and economic burden for both the patient himself and society. Reported risk factors for the malignant transformation of keratinocytes and development of SCC include ultraviolet light exposure, followed by chronic scarring and inflammation, exposure to chemical compounds (arsenic, insecticides, and pesticides), and immune-suppression. Despite various available treatment methods and recent advances in noninvasive or minimal invasive diagnostic techniques, the risk recurrence and metastasis are far from being negligible, even in patients with negative histological margins and lymph nodes. Analyzing normal, dysplastic, and malignant keratinocyte proteome holds special promise for novel biomarker discovery in SCC that could be used in the future for early detection, risk assessment, tumor monitoring, and development of targeted therapeutic strategies

Standardization of clinical protocols in oral malodor research

The objective of this study is to standardize protocols for clinical research into oral malodor caused by volatile sulfur compounds (VSCs). To detect VSCs, a gas chromatograph (GC) using a flame photometric detector equipped with a bandpass filter (at 393 nm) is the gold standard (sensitivity: 5 x 10 (11) gS s (1)). The baselines of VSC concentrations in mouth air varied considerably over a week. When the subjects refrained from eating, drinking and oral hygiene including mouth rinsing, the VSC concentrations remained constant until eating. Over a 6 h period after a meal, VSC concentrations decreased dramatically (p <0.01). These results point to optimal times and conditions for sampling subjects. Several portable devices were compared with the measurements by the GCs. Portable GCs demonstrated capabilities similar to those of the GCs. We also applied the recommended protocols described below to clinical research testing the efficacy of ZnCl2 products, and confirmed that using the recommended protocols in a randomized crossover design would provide very clear results. Proposed protocols include: (a) a short-term study rather than a long-term study is strongly recommended, since the VSC concentrations are constant in the short term; (b) a crossover study would be the best design to avoid the effects of individual specificities on each clinical intervention; (c) measurements of VSCs should preferably be carried out using either a GC or portable GCs

PLGA Nanoparticles Uptake in Stem Cells from Human Exfoliated Deciduous Teeth and Oral Keratinocyte Stem Cells

Polymeric nanoparticles have been introduced as a delivery vehicle for active compounds in a broad range of medical applications due to their biocompatibility, stability, controlled release of active compounds, and reduced toxicity. The oral route is the most used approach for delivery of biologics to the body. The homeostasis and function of oral cavity tissues are dependent on the activity of stem cells. The present work focuses, for the first time, on the interaction between two types of polymeric nanoparticles, poly (lactic-co-glycolic acid) or PLGA and PLGA/chitosan, and two stem cell populations, oral keratinocyte stem cells (OKSCs) and stem cells from human exfoliated deciduous teeth (SHEDs). The main results show that statistical significance was observed in OKSCs uptake when compared with normal keratinocytes and transit amplifying cells after 24 h of incubation with 5 and 10 &micro;g/mL PLGA/chitosan. The CD117+ SHED subpopulation incorporated more PLGA/chitosan nanoparticles than nonseparated SHED. The uptake for PLGA/chitosan particles was better than for PLGA particles with longer incubation times, yielding better results in both cell types. The present results demonstrate that nanoparticle uptake depends on stem cell type, incubation time, particle concentration, and surface properties