Cytotoxic Effects of 5-Azacytidine on Primary Tumour Cells and Cancer Stem Cells from Oral Squamous Cell Carcinoma: An In Vitro FTIRM Analysis

In the present study, the cytotoxic effects of 5-azacytidine on primary Oral Squamous Cell Carcinoma cells (OSCCs) from human biopsies, and on Cancer Stem Cells (CSCs) from the same samples, were investigated by an in vitro Fourier Transform InfraRed Microscospectroscopy (FTIRM) approach coupled with multivariate analysis. OSCC is an aggressive tumoral lesion of the epithelium, accounting for ~90% of all oral cancers. It is usually diagnosed in advanced stages, and this causes a poor prognosis with low success rates of surgical, as well as radiation and chemotherapy treatments. OSCC is frequently characterised by recurrence after chemotherapy and by the development of a refractoriness to some employed drugs, which is probably ascribable to the presence of CSCs niches, responsible for cancer growth, chemoresistance and metastasis. The spectral information from FTIRM was correlated with the outcomes of cytotoxicity tests and image-based cytometry, and specific spectral signatures attributable to 5-azacytidine treatment were identified, allowing us to hypothesise the demethylation of DNA and, hence, an increase in the transcriptional activity, together with a conformational transition of DNA, and a triggering of cell death by an apoptosis mechanism. Moreover, a different mechanism of action between OSSC and CSC cells was highlighted, probably due to possible differences between OSCCs and CSCs response

Multidisciplinary evaluation of the remineralization potential of three fluoride-based toothpastes on natural white spot lesions.

OBJECTIVES This in vitro study aimed assessing the remineralization potential of three commercial fluoride-based toothpastes in permanent teeth with natural white spot lesions (WSLs). A multidisciplinary approach based on Raman microspectroscopy (RMS), Scanning electron microscopy (SEM), Energy-dispersive x-ray spectroscopy (EDS), and Vickers microhardness (VMH) was exploited. METHODS N = 12 human molars with natural WSLs in the proximal-vestibular zone were selected and divided into 4 groups (n = 3) according to the different treatments: HAF (hydroxyapatite with fluoride ions); SMF (sodium monofluorophosphate with arginine); SF (sodium fluoride with enzymes), and CTRL (untreated group). All toothpastes tested contained 1450 ppm of fluoride. Teeth samples were submitted to the following protocol: a 7-day pH cycling treatment, with two daily exposures (2 min each time) to the commercial toothpastes described above. The surface micromorphology (SEM), the chemical/elemental composition (RMS and EDS), and the Vickers microhardness (VMH) were evaluated. Statistical analysis was performed. RESULTS A remarkable remineralization of WSLs in SEM images was observed in all treated groups compared to CTRL. In particular, HAF and SF displayed higher values of VMH, phosphates amount (I960), crystallinity (FWHM960), and lower ones of C/P (I1070/I960) with respect to CTRL. Intermediate values were found in SMF, higher than CTRL but lower with respect to HAF and SF. As regards the Ca/P ratio, statistically significant differences (p < 0.05) were found between SF and the other groups. CONCLUSIONS All the tested dentifrices have shown to remineralize the WSLs. SF and HAF have comparable capability in hardness recovery and crystallinity; however, SF shows the best remineralizing potential according to both micromorphological and chemical analyses. Clinical relevance The daily use of toothpastes containing hydroxyapatite partially replaced with fluoride, sodium monofluorophosphate with arginine and sodium fluoride toothpaste associated with enzymes represents a preventive, therapeutic, effective, and non-invasive tool for remineralize WSLs

Efficacy of an All-Natural Polyherbal Mouthwash in Patients With Periodontitis: A Single-Blind Randomized Controlled Trial

Aim: This study aimed to evaluate the anti-inflammatory effect and the incidence of adverse effects of an all-natural polyherbal mouthwash in patients with periodontitis, after 3 months of use. These aims were accomplished by using full mouth bleeding score (FMBS), full mouth plaque score (FMPS), probing depth (PD) clinical attachment level (CAL) and a questionnaire recording any adverse events.Methods: The present randomized controlled clinical study considered 40 patients with moderate or severe periodontitis, randomized in two groups: a test group (TG) and a control group (CG). TG was instructed to use a polyherbal mouthwash composed of Propolis resin extract, Plantago lanceolata, Salvia officinalis leaves extract, and 1.75% of essential oils and the CG was given a placebo mouthwash. Both groups were instructed to rinse for 2 min, twice daily after their routine oral home care with the different mouthwashes. Clinical measurements of FMBS, FMPS, PD and CAL were recorded at baseline (T0) and after 3 months (T1). The incidence of adverse outcomes was recorded at every follow-up. Mann–Whitney U test and Wilcoxon signed-rank test were used for the statistical analysis (p &lt; 0.05).Results: The final study sample consisted of 34 healthy individuals, 17 individuals in each of the two groups. TG and CG showed a statistically significant reduction in FMBS (p = 0.001 TG; p = 0.002 CG), FMPS (p = 0.001 TG; p = 0.003 CG), PD (p = 0.001 TG; p = 0.011 CG) and CAL (p &lt; 0.001 TG; p = 0.020 CG) values from baseline to 3 months. The TG showed a statistically significant decrease in FMBS and FMPS compared with the CG. No adverse events or side effects were reported or observed in both groups.Conclusion: The use of polyherbal mouthwash in patients with moderate or severe periodontitis has proved safe and effective in reducing bleeding score and plaque accumulation, after 3 months, compared with placebo, although no difference between the two groups were reported on PD and CAL (both improving at T1)

Biological Oriented Immediate Loading: A New Mathematical Implant Vertical Insertion Protocol, Five-Year Follow-Up Study

One of the current major challenges in implant therapy is to minimize marginal bone loss around implants, since it can trigger bacterial colonization of the implant's neck, leading to its failure. The present study aimed (1) to scientifically validate a new mathematical rule based on soft tissues thickness, for choosing the correct implant position with respect to the bone level, in order to provide a better tissue adaptation to the abutment/implant surface to avoid bacterial invasion, and (2) to apply this mathematical rule to the Biological Oriented Immediate Loading (B.O.I.L.) surgical protocol, avoiding peri-implant bone resorption. N. 127 implants were inserted following B.O.I.L. protocol: implants were placed according to the mathematical rule Y = X - 3, which correlates the position of the implant from the bone crest level (Y) with the thickness of the soft tissues (X). All the implants were inserted in fresh extraction sockets, and immediately loaded with temporary abutments and prostheses. Bone levels were evaluated through radiographic examination just after surgical procedure (T0), and after 10 days (10D), 6 months (6M), 1 year (1Y), and 5 years (5Y). After 5 years, the implant survival rate was 100%, with a medium marginal bone loss around implants of 0.0704 mm (SD = 0.169 mm). One-way ANOVA, followed by Tukey's multiple comparison test was performed for statistical evaluations (p < 0.05). This protocol provided a safe and successful procedure, with a good soft tissue seal against bacterial challenge. The application of the mathematical rule allows the implant placement in a correct vertical position from the bone crest, avoiding bone resorption and bacterial infiltrations. Moreover, the use of Multi Unit Abutment (MUA) determined a stable biological seal, favouring the implant healing and preserving the adhesion of hemidesmosomes to the titanium of MUA

Infrared spectroscopy as a new tool for studying single living cells: Is there a niche?

FTIR spectroscopy is an analytical technique widely applied for studying the vibrational fingerprint of organic compounds. In recent years, it has been applied to many biomedical fields because of its potential to detect the composition and molecular structure of various biological materials without the need of probe molecules. The coupling of IR spectrometers with visible microscopes has led to perform the imaging analysis of non-homogeneous samples, such as tissues and cells, in which the biochemical and spatial information are close related. In this review, we report the most significant applications of FTIR to the study of cells in different conditions (fixed, dried and living) with the aim to monitor their biochemical modifications, either induced or naturally occurring

ATR-FTIR Analysis of Orthodontic Invisalign^® Aligners Subjected to Various In Vitro Aging Treatments

Clear and removable tooth aligners for orthodontics treatments have become an increasingly popular alternative to fixed appliances. Even if protocols suggest removing aligners before eating or drinking, most patients retain them when they drink beverages. Alterations in the material during the daily use could determine a reduction in the application forces, affecting the desired orthodontic movement; the knowledge of how this material reacts when subjected to different aging processes is mandatory to establish the predictability of the orthodontic treatment. According to this, the aim of the present study was to assess a new objective approach, coupling spectroscopic and chemometric tools, to evaluate the changes occurring in Invisalign® aligners, the most widely used brand, exposed in vitro to coffee, tea, Coca Cola® and UV radiation for 24 and 48 h. In particular, ATR-FTIR spectroscopy was utilized to characterize, at the molecular level, the chemical and color modifications in the surfaces of the appliances; the obtained data were submitted to PCA and one-way ANOVA and Tukey’s multiple comparison test. Moreover, a colorimetry analysis was carried out to evaluate any changes in color and transparency. Coffee and tea samples displayed the major color changes between the tested groups. The differences highlighted in the spectral features of coffee, tea and UV-treated samples were mainly ascribable to color and transparency changes, because the chemical properties remained unaltered

Non-Cariogenic Effect of Milk and Dairy Products on Oral Health in Children and Adolescents: A Scoping Review

Diet plays an important role in the etiopathology of dental caries. Milk and dairy products (DPs), especially in children and adolescents, are important sources of protein, calcium and phosphorus and could have an effect on dental and oral health. The aim of this scoping review was to analyze the scientific literature on the non-cariogenic effect of milk and DPs, with a focus on their potential to prevent dental caries in children and adolescents. PubMed, EMBASE, and Web of Science were searched for publications relevant to our topic from January 2013 to 30 September 2023. Thirty-eight studies were included in the qualitative analysis. The included studies highlight the properties of milk and DPs that contribute to enamel remineralization, exhibit antibacterial action, inhibit the growth of cariogenic bacteria, and promote a balanced oral microbiome. With regard to the addition of probiotics (PBs) and fluoride (F) to DPs, the mixed results of the studies analyzed did not allow a clear statement to be made about their non-cariogenic effects. However, several studies show that the addition of PBs can reduce cariogenic bacteria, create a protective barrier against pathogens and support the host’s natural defense mechanisms. Further long-term and high-quality studies are needed to understand the impact of milk and its constituents on oral health in order to promote effective caries prevention strategies in children and adolescents

How Can Different Polishing Timing Influence Methacrylate and Dimethacrylate Bulk Fill Composites? Evaluation of Chemical and Physical Properties

The polishing procedure is commonly performed after direct composite restorations, and little information exists regarding the right timing during which it should be performed on bulk fill composites. This study investigated the effect of polishing timing on the degree of conversion (DC), Vickers microhardness (VMH), and surface morphology of a methacrylate- (MET-) and dimethacrylate- (DMET-) based bulk fill composite, by using FT-NIR, microhardness tester, and SEM. Composite samples were divided as follows: in Group I (immediate), samples were polished immediately after curing (t 0); in Group D (delayed), samples were polished after 24 h from curing (t 24), whereas the unpolished samples were considered as controls (Group C). The DC and VMH values were evaluated before and after polishing, at t 0 and t 24. Statistical analysis was performed with a significance level set at p < 0.05. At t 0, DC increased after polishing in both tested composites (p < 0.05), while at t 24, Group I and Group D were not different. By considering VMH, in the case of MET, all groups were not different both at t 0 and t 24. On the other hand, at t 0, VMH values of DMET increased after polishing. At t 24, DMET Group I and DMET Group D were not different. Qualitative evaluations of scanning electron micrographs showed that the surface morphology of MET presented a more irregular aspect than the DMET one. In summary, since the immediate polishing of MET can improve the DC, without negatively affecting VMH, but showing an irregular surface, it is suggested to wait 24 hours before proceeding with polishing. Otherwise, for DMET, the immediate polishing could definitively be recommended, since it improves both DC and VMH, also producing a regular surface. Therefore, clinicians may always safely polish a restoration performed using DMET-based bulk fill composites in one-chair appointment, avoiding a second appointment

A spectroscopic study on orthodontic aligners: First evidence of secondary microplastic detachment after seven days of artificial saliva exposure

Clear orthodontic aligners have recently seen increasing popularity. The thermoplastic materials present several ad- vantages, even if it is known that all plastic products can be subjected to environmental and mechanical degradation, leading to the release of microplastics (MPs). Their ingestion could cause oxidative stress and inflammatory lesions. This study aims to evaluate the potential detachment of MPs by clear aligners due to mechanical friction simulated with a 7-day protocol in artificial saliva. The study was performed on orthodontic clear aligners from different manu- facturers: Alleo (AL); FlexiLigner (FL); F22 Aligner (F22); Invisalign® (INV); Lineo (LIN); Arc Angel (ARC), and Ortobel Aligner (OR). For each group, two aligners were immersed in artificial saliva for 7 days and stirred for 5 h/ day, simulating the physiological teeth mechanical friction. After 7 days, the artificial saliva was filtered; then, filters were analyzed by Raman Microspectroscopy (RMS) and Scanning Electron Microscopy (SEM), respectively to chemi- cally identify the polymeric matrix and to measure the number and size of the detected MPs. RMS spectra revealed that AL, FL, LIN, ARC, and OR aligners were composed by polyethylene terephthalate, while F22 and INV ones by poly- urethane. SEM analysis showed that the highest number of MPs was found in ARC and the lowest in INV (p < 0.05). As regards MPs' size, no statistically significant difference was found among groups, with most MPs ranging from 5 to 20 μm. Noteworthy, a highly significant correlation (p < 0.0001) was highlighted between the distribution of MPs size and the different typologies of aligners. This in vitro study highlighted for the first time the detachment of MPs from clear aligners due to mechanical friction. This evidence may represent a great concern in the clinical practice since it could impact human general health