Mandibular bone mass density in a medieval population and its relationship with stable isotopes δ13C and δ15N.

The aim of this study was to compare the level of bone mass in digital orthopantomograms in two populations (medieval and current) using two radiomorphometric indexes, and to correlate the mandibular bone mass value, in the medieval mandible population, with stable isotope data δ13C and δ15N. An observational, cross-sectional, and analytical study on mandibles from two diachronic groups, 15 mandibles from the medieval settlement of La Torrecilla (Granada, Spain) and 15 mandibles from current patients at the Faculty of Dentistry of the University of Granada (Spain), matched by age and sex was conducted. The bone mass density was determined using the Mandibular Cortical Width Index (MCW) and the Mandibular Panoramic Index (PMI) in digital panoramic radiographs. In the medieval group, the values of bone mass density were correlated with those of two stable isotopes (δ13C and δ15N). The mean value of MCW in mm in the medieval group was 3.96 ± 0.60 (mean ± standard deviation) and in the current group was 4.02 ± 1.01. The PMI was 0.33 ± 0.06 and 0.35 ± 0.08 in the medieval and current groups respectively, with similar results in both groups (p = 0.820 and p = 0.575). A negative correlation was found between both morphometric indices and the δ15N isotope (rs = 0.56, p = 0.030 and rs = 0.61, p = 0.016, respectively). The bone mass density in mandibles belonging to the two compared populations, determined by two quantitative radiomorphometric indices, is similar. Within the medieval population, there is an inverse correlation between the δ15N value and bone mass density.

Virtual indentation of the empty capsid of the minute virus of mice using a minimal coarse-grained model.

A minimal coarse-grained model for T=1 viral capsids assembled from 20 protein rigid trimers has been designed by extending a previously proposed form of the interaction energy written as a sum of anisotropic pairwise interactions between the trimeric capsomers. The extension of the model has been performed to properly account for the coupling between two internal coordinates: the one that measures the intercapsomer distance and the other that gives the intercapsomer dihedral angle. The model has been able to fit with less than a 10% error the atomic force microscopy (AFM) indentation experimental data for the empty capsid of the minute virus of mice (MVM), providing in this way an admissible picture of the main mechanisms behind the capsid deformations. In this scenario, the bending of the intercapsomer dihedral angle is the angular internal coordinate that can support larger deformations away from its equilibrium values, determining important features of the AFM indentation experiments as the elastic constants along the three symmetry axes of the capsid and the critical indentations. From the value of one of the parameters of our model, we conclude that trimers in the MVM must be quite oblate tops, in excellent agreement with their known structure. The transition from the linear to the nonlinear regimes sampled in the indentation process appears to be an interesting topic for future research in physical virology.

Clinical comparison of marginal fit of ceramic inlays between digital and conventional impressions.

PURPOSE: The aim of this stuldy was to compare the clinical marginal fit of CAD-CAM inlays obtained from intraoral digital impression or addition silicone impression techniques. MATERIALS AND METHODS: The study included 31 inlays for prosthodontics purposes of 31 patients: 15 based on intraoral digital impressions (DI group); and 16 based on a conventional impression technique (CI group). Inlays included occlusal and a non-occlusal surface. Inlays were milled in ceramic. The inlay-teeth interface was replicated by placing each inlay in its corresponding uncemented clinical preparation and taking interface impressions with silicone material from occlusal and free surfaces. Interface analysis was made using white light confocal microscopy (WLCM) (scanning area: 694 × 510 µm2) from the impression samples. The gap size and the inlay overextension were measured from the microscopy topographies. For analytical purposes (i.e., 95-%-confidence intervals calculations and P-value calculations), the procedure REGRESS in SUDAAN was used to account for clustering (i.e., multiple measurements). For p-value calculation, the log transformation of the dependent variables was used to normalize the distributions. RESULTS: Marginal fit values for occlusal and free surfaces were affected by the type of impression. There were no differences between surfaces (occlusal vs. free). Gap obtained for DI group was 164 ± 84 µm and that for CI group was 209 ± 104 µm, and there were statistical differences between them (p = .041). Mean overextension values were 60 ± 59 µm for DI group and 67 ± 73 µm for CI group, and there were no differences between then (p = .553). CONCLUSION: Digital impression achieved inlays with higher clinical marginal fit and performed better than the conventional silicone materials.

Cone-beam Computed Tomography Analysis of the Root Canal Morphology of Mandibular Incisors Using Two Classification Systems in a Spanish Subpopulation: A Cross-Sectional Study.

OBJECTIVE: This study evaluated the root and canal morphology in permanent mandibular incisors teeth using cone-beam computer tomography imaging in a Spanish subpopulation, and compared these findings with ipsilateral (similarity) and contralateral (symmetry) incisors. In addition, the position of canal splitting was measured. METHODS: A total of 229 datasets comprising four mandibular teeth each (n=916 incisors) were analysed using Vertucci and Ahmed et al. classifications, and, the similarity and symmetry were calculated. The distance from the cemento-enamel junction (CEJ), and the most coronal canal divergence was measured (if present). The role of sex was also assessed. The Cochran Q Test, LOGIS PROC in SUDAAN, Chi-square, and Kappa were used for the different comparisons. A p-value of less than 0.05 was considered significant. RESULTS: All incisors were single-rooted and no significant differences regarding root canal morphology were found according to the sex of the subjects included in the database. The most common morphology was Vertucci type I/Ahmed et al. 1MI1(65.3% for central and 66.8% for lateral incisors respectively), followed by type III/1MI1-2-1 (31% for central and 30.6% for lateral incisors). 1.8% of the samples were considered as non-classifiable with Vertucci but were classified with codes using the Ahmed et al. system. Similarity values were 74.7% for the left side, and 74.2% for the right side, whereas symmetry values were 90% for central and 84.3% for lateral incisors. In the presence of divergences, the main (SD) distances from the CEJ were for type II/1MI1-2-1 3.8+-0.8 (centrals) 4.0+-0.7 mm (laterals); for type V/1MI1-2 this value ranged between 6.0+-1.8 and 5.5+-1.5 mm, whereas values for 1MI1-2-3-2-1 were 1.8 and 2.1 mm. No significant differences were found when the position of the most coronal divergence was compared between lateral and central incisors for the different morphologies. CONCLUSION: A high prevalence of Vertucci I/Ahmed et al. 1MI1 configuration was present in mandibular incisors from Spanish individuals. Similarity and symmetry were common, particularly for central incisors. The position of the coronal splitting of the canals varied according to the root canal morphology.

Fracture Resistance Comparative Analysis of Milled-Derived vs. 3D-Printed CAD/CAM Materials for Single-Unit Restorations.

The aim of this study was to evaluate and compare the fracture resistance of a single-unit fixed prosthesis, using a CAD/CAM PMMA material and two printed materials (3DPPa and 3DPPb). A typodont with a specific preparation for a full crown was used; a digital impression was made with a state-of-the-art scanner (PrimeScanTM, Dentsply-SironaTM, New York, NY, USA), and a full coverage restoration was designed using a biogeneric design proposal by means of specific software (InLAB 22.1, Dentsply-Sirona, NY, USA). Sixty crowns were prepared, divided into three groups according to the material: 3DPPa (n = 20), 3DPPb (n = 20), both 3D-printed from the .STL file with a resolution of 50 µm, and PMMA (n = 20) milled-derived, which were subjected to a thermocycling process. A universal testing machine (Universal/Tensile Testing Machine, Autograph AGS-X Series) with integrated software (TRAPEZIUM LITE X) equipped with a 20 kN load cell was used to determine the fracture resistance. Significant differences were found by Kruskal-Wallis test and multiple comparisons (p < 0.05) in fracture resistance between materials. The fracture resistance for the PMMA material was higher, and the standard deviation was lower (x = 1427.9; sd = 36.9 N) compared to the 3DPPa (x = 1231; sd = 380.1 N) and 3DPPb (x = 1029.9; sd = 166.46 N) prints. The restorations from the milled-derived group showed higher average fracture resistance than the provisional restorations obtained from the printed groups. However, the results demonstrated that all three materials analyzed in single-unit restorations are capable of withstanding the average masticatory forces.

Randomized clinical trial on the clinical effects of a toothpaste containing extra virgin olive oil, xylitol, and betaine in gingivitis.

To determine the effects on gingival bleeding, dental biofilm, and salivary flow and pH in patients with gingivitis of using toothpaste with extra-virgin olive oil (EVOO), xylitol, and betaine in comparison to a placebo or commercial toothpaste. This controlled, double blinded, and multicenter randomized clinical trial included patients with gingivitis randomly assigned to one of three groups: test group (EVOO, xylitol, and betaine toothpaste), control group 1 (placebo toothpaste), or control group 2 (commercial toothpaste). Percentage supragingival biofilm and gingival bleeding were evaluated at baseline (T0), 2 months (T2), and 4 months (T4), measuring non-stimulated salivary flow and salivary pH. Comparisons were performed between and within groups. The final study sample comprised 20 in the test group, 21 in control group 1, and 20 in control group 2. In comparison to control group 1, the test group showed significantly greater decreases in gingival bleeding between T4 and T0 (p = 0.02) and in biofilm between T2 and T0 (p = 0.02) and between T4 and T0 (p = 0.01). In the test group, salivary flow significantly increased between T2 and T0 (p = 0.01), while pH alkalization was significantly greater between T4 and T0 versus control group 2 (p = 0.01) and close-to-significantly greater versus control group 1 (p = 0.06). The toothpaste with EVOO, xylitol, and betaine obtained the best outcomes in patients with gingivitis, who showed reductions in gingival bleeding and supragingival biofilm and an increase in pH at 4 months in comparison to a commercial toothpaste.

Chemical Characterization, Antioxidant Capacity and Anti-Oxidative Stress Potential of South American Fabaceae Desmodium tortuosum.

It has been proposed that oxidative stress is a pathogenic mechanism to induce cytotoxicity and to cause cardiovascular and neuronal diseases. At present, natural compounds such as plant extracts have been used to reduce the cytotoxic effects produced by agents that induce oxidative stress. Our study aimed to evaluate the antioxidant and cytoprotective capacity of Desmodium tortuosum (D. tortuosum) extract in the co- and pre-treatment in EA.hy926 and SH-SY5Y cell lines subjected to oxidative stress induced by tert-butylhydroperoxide (t-BOOH). Cell viability, reactive oxygen species (ROS), nitric oxide (NO), caspase 3/7 activity, reduced glutathione (GSH), glutathione peroxidase (GPx), glutathione reductase (GR), and molecular expression of oxidative stress biomarkers (SOD2, NRF2 and NFκB1) and cell death (APAF1, BAX, Caspase3) were all evaluated. It was observed that the D. tortuosum extract, in a dose-dependent manner, was able to reduce the oxidative and cytotoxicity effects induced by t-BOOH, even normalized to a dose of 200 µg/mL, which would be due to the high content of phenolic compounds mainly phenolic acids, flavonoids, carotenoids and other antioxidant compounds. Finally, these results are indicators that the extract of D. tortuosum could be a natural alternative against the cytotoxic exposure to stressful and cytotoxic chemical agents.

Synthesis of fluorescent chalcones, photophysical properties, quantitative structure-activity relationship and their biological application.

The development of fluorescent pigments is an area of interest in several research fields due to their high sensitivity. In the current study-eight known and three new N,N-dimethylamino-chalcones (12a-k) were synthesized with good yields using the Claisen-Schmidt reaction. For each molecular system, the photophysical properties, including the maximum absorption wavelength (λAbsorption), molar absorption coefficient (ε), maximum excitation wavelength (λExcitation), maximum emission wavelength (λEmission), Stokes Shift (Δλ), fluorescence quantum yield (Φfl), fluorescence lifetime (τfl), radiative and non-radiative rate constants (kR and kNR, respectively) were evaluated. Variations in each of these properties were analyzed depending on the substituents present on each compound. To relate the chemical structures of the synthesized compounds to their photophysical properties, Hansch analysis (2D-QSPR) was applied. As a result of Hansch analysis, we found different photophysical properties related to molecular orbitals and the energy of their derivatives (Highest Occupied Molecular Orbital-HOMO, Lowest Unoccupied Molecular Orbital-LUMO, Difference between LUMO-HOMO-ΔLH, Chemical potential-µ, Hardness-η, Softness-S, and electrophilic global index-ω) as well as to the atomic charges on atoms C5, Cα, Cß, and CO. The application of this type of analysis has made it possible to understand and subsequently design new molecules with defined photophysical properties. Finally, the compounds were use as fluorescent pigment to get living cell imaging on breast cancer cells, obtaining the compound 12a as promissory alternative.

Improving bitter pit prediction by the use of X-ray fluorescence (XRF): A new approach by multivariate classification.

Bitter pit (BP) is one of the most relevant post-harvest disorders for apple industry worldwide, which is often related to calcium (Ca) deficiency at the calyx end of the fruit. Its occurrence takes place along with an imbalance with other minerals, such as potassium (K). Although the K/Ca ratio is considered a valuable indicator of BP, a high variability in the levels of these elements occurs within the fruit, between fruits of the same plant, and between plants and orchards. Prediction systems based on the content of elements in fruit have a high variability because they are determined in samples composed of various fruits. With X-ray fluorescence (XRF) spectrometry, it is possible to characterize non-destructively the signal intensity for several mineral elements at a given position in individual fruit and thus, the complete signal of the mineral composition can be used to perform a predictive model to determine the incidence of bitter pit. Therefore, it was hypothesized that using a multivariate modeling approach, other elements beyond the K and Ca could be found that could improve the current clutter prediction capability. Two studies were carried out: on the first one an experiment was conducted to determine the K/Ca and the whole spectrum using XRF of a balanced sample of affected and non-affected 'Granny Smith' apples. On the second study apples of three cultivars ('Granny Smith', 'Brookfield' and 'Fuji'), were harvested from two commercial orchards to evaluate the use of XRF to predict BP. With data from the first study a multivariate classification system was trained (balanced database of healthy and BP fruit, consisting in 176 from each group) and then the model was applied on the second study to fruit from two orchards with a history of BP. Results show that when dimensionality reduction was performed on the XRF spectra (1.5 - 8 KeV) of 'Granny Smith' apples, comparing fruit with and without BP, along with K and Ca, four other elements (i.e., Cl, Si, P, and S) were found to be deterministic. However, the PCA revealed that the classification between samples (BP vs. non-BP fruit) was not possible by univariate analysis (individual elements or the K/Ca ratio).Therefore, a multivariate classification approach was applied, and the classification measures (sensitivity, specificity, and balanced precision) of the PLS-DA models for all cultivars evaluated ('Granny Smith', 'Fuji' and 'Brookfield') on the full training samples and with both validation procedures (Venetian and Monte Carlo), ranged from 0.76 to 0.92. The results of this work indicate that using this technology at the individual fruit level is essential to understand the factors that determine this disorder and can improve BP prediction of intact fruit.

Sensitive fluorescent chemosensor for Hg(II) in aqueous solution using 4'-dimethylaminochalcone.

Mercury (Hg) is an element with high toxicity, especially to the nervous system, and fluorescent pigments are used to visualize dynamic processes in living cells. A little explored fluorescent core is chalcone. Herein, we synthesized chalcone (2E)-3-(4-(dimethylamino)phenyl)-1-phenylprop-2-en-1-one (8) and assessed its photophysical properties. Moreover, the application of this chemosensor in aqueous media shows a selective fluorescence quenching effect with Hg(II). The figures of merit for the chemosensor were calculated to be LOD = 136 nM and LOQ = 454 nM, as well as a stoichiometry of 1:1. Furthermore, the association constant (Ka) and fluorescence quenching constant (KSV) were calculated using the Benesi-Hildebrand and Stern-Volmer equations to be Ka= 9.08 × 104 and KSV= 1.60 × 105, respectively. Finally, by using a computational approach, we explain the interaction between chalcone (8) and Hg(II) and propose a potential quenching mechanism based on the blocking of photoinduced electron transfer.

Prevention of Occupational Hazards Due to Asbestos Exposure in Dentistry. A Proposal from a Panel of Experts.

Asbestos in all its forms is a Group 1 material agent with proven carcinogenic effects in the human being since 1977. Exposure to asbestos can be considered unsafe. The use of asbestos in the field of dentistry had a common use in the manufacture of dental prostheses in the 1960s and 1970s. Taking into account the long induction period of this agent and the plausibility for being a risk factor in dentistry, the objective of this study is to propose a plan for the prevention of occupational risks due to asbestos exposure in dentistry by means of the contribution of a panel of experts. An Expert Panel (EP) approach was used in which a group of nine experts identified and documented the use of asbestos in the dental profession. EP was created and followed the protocol in accordance with the EuropeAid Assessment Guidelines. As a result of this study, EP documented the common use and sources of asbestos in dentistry in prosthetic materials, dental dressings, and in the coating of casting cylinders. EP also created a consensus document on the priority measures for the Plan for the Prevention of Risks from Asbestos in Dentistry, based on previous reports from the European Commission Senior Labour Inspectors' Committee. The document concluded that obtainment of information, receiving specific training on the subject and performing epidemiological studies, and the proper risk assessments were the priority measures to adopt.

Patients with periodontitis and erectile dysfunction suffer a greater incidence of major adverse cardiovascular events: A prospective study in a Spanish population.

BACKGROUND: Periodontitis and erectile dysfunction (ED) have been linked with cardiovascular disease. The association of periodontitis and ED with the occurrence of major adverse cardiovascular events has not been previously assessed. The aim of this study was to determine if the presence of periodontitis and ED has any effect on the incidence of major adverse cardiovascular events. METHODS: Male patients that attended the Urology service were enrolled in a prospective study. Erectile dysfunction was diagnosed according to the International Index of Erectile Function. Sociodemographic data and periodontal clinical parameters were gathered (pocket probing depth, clinical attachment loss, bleeding on probing (BoP), plaque index and number of teeth) at baseline. Major adverse cardiovascular events occurred both before and during the follow-up time were registered. Bivariate analyses, as well as a multivariate analysis were performed, adjusting for potential confounders. RESULTS: A total of 158 patients were included, with a mean follow-up of 4.2 years. A greater number of major adverse cardiovascular events occurred in the group that presented periodontitis and ED (P = 0.038). After adjusting by age and previous cardiovascular disease in the multivariate analysis, the annual major adverse cardiovascular event rate was estimated to be 3.7 times higher in the same group (P = 0.049). Other periodontal clinical variables together with ED supported these results and were close to statistical significance. CONCLUSIONS: Patients with periodontitis and ED, adjusted by age and a cardiovascular disease, showed 3.7 times more risk of suffering major adverse cardiovascular events after mean follow-up of 4.2 years.

Global issues in setting legal limits on soil metal contamination: A case study of Chile.

The establishment of legal limits for soil contamination with trace elements is a global issue that has not yet been resolved. However, the resolution of any global problem begins at the national level. In this vein, we present the case of Chile, the world's leading copper producer, where soil contamination by trace elements in mining areas has been severe. We evaluated the magnitude of the ecological and human health risks from exposure to arsenic (As), copper (Cu), zinc (Zn), and lead (Pb) in soils of the La Ligua and Petorca basins, two important mining areas in Chile. Contrary to what might be expected in soils affected by Cu mining activities, As was identified as the most hazardous element in the studied soils, both in terms of ecological and human health risks. On the other hand, Chile does not currently have specific legislation establishing legal limits on soil contamination with trace elements. Since Chile is geochemically similar to New Zealand, Mexico, and Italy, we used the limits of these three countries as benchmarks. We determined the background concentrations of As, Cu, Zn, and Pb in the soils of the two river basins under study and found that they tend to exceed the limits established by foreign laws. We also found that the differences in background elemental concentrations in the studied soils were primarily due to the varied lithology of soil-forming rocks. This means that absolute "one-limit-fits-all" values of element concentrations may not be adequate to regulate the level of soil contamination in areas affected by mining. As a fundamental first step, it is necessary to establish background soil concentrations of trace elements in each river basin in Chile. It is clear that Chile urgently needs to move from rubber-stamping foreign laws to the development of national legislation on soil metal contamination.

Minimal Design Principles for Icosahedral Virus Capsids.

The geometrical structures of single- and multiple-shell icosahedral virus capsids are reproduced as the targets that minimize the cost corresponding to relatively simple design functions. Capsid subunits are first identified as building blocks at a given coarse-grained scale and then represented in these functions as point particles located on an appropriate number of concentric spherical surfaces. Minimal design cost is assigned to optimal spherical packings of the particles. The cost functions are inspired by the packings favored for the Thomson problem, which minimize the electrostatic potential energy between identical charged particles. In some cases, icosahedral symmetry constraints are incorporated as external fields acting on the particles. The simplest cost functions can be obtained by separating particles in disjoint nonequivalent sets with distinct interactions, or by introducing interacting holes (the absence of particles). These functions can be adapted to reproduce any capsid structure found in real viruses. Structures absent in Nature require significantly more complex designs. Measures of information content and complexity are assigned to both the cost functions and the capsid geometries. In terms of these measures, icosahedral structures and the corresponding cost functions are the simplest solutions.

Delivery of Health Care by Spanish Dental Hygienists in Private and Public Dental Services during the COVID-19 De-Escalation Phase (June 2020): A Cross-Sectional Study.

BACKGROUND: The first wave of the COVID-19 pandemic in Spain posed a major challenge for Spanish dental professionals. The objective of this work is to describe the dental hygienists' work status and employment patterns during the de-escalation phase in order to analyse the standards of knowledge, compliance with official recommendations, and dental activities both in the public health service and in the private sector. MATERIAL AND METHODS: A cross-sectional questionnaire was answered by Spanish dental hygienists via WhatsApp, Facebook, and Instagram. The questionnaire was piloted before it was distributed and carried out during June 2020. RESULTS: Here, 517 dental hygienists were surveyed, of which 86.2% followed the official recommendations to avoid contagion and 63.8% agreed with the gradual return to work by limiting the use of aerosols. Private dental hygienists identified more with returning to work without restrictions (14.5%) versus those working for the public service (1.2%) (p < 0.005). CONCLUSIONS: Dental hygienists' return to work has involved different strategies, aimed at controlling infection and guaranteeing the safety of patients and the rest of the dental team. The availability of personal protective equipment, the adaptation of clinical infrastructure, and patient care management have differed between professionals working in the private and public sectors.

Periodontal Treatment by Dental Undergraduate Students: Assessment of the Patient's Oral Quality of Life - A Prospective Pilot Study.

PURPOSE: To assess the impact of nonsurgical periodontal treatment, performed by undergraduate dental students, on oral health-related quality of life of patients with periodontitis. MATERIALS AND METHODS: An observational, prospective, single-arm cohort study with pre­post test involving 31 undergraduate dental students was performed. A complete periodontal examination was performed before and after receiving nonsurgical periodontal treatment. The main independent clinical variables assessed were the degree of periodontal inflammation and the number of teeth with periodontitis. Oral health-related quality of life was assessed before and after treatment through the Oral Impacts on Daily Performances (OIDP) questionnaire. The association between the extent of periodontal treatment (measured as number of treated teeth) and final OIDP score was assessed, adjusting for age, sex, and baseline OIDP, in a multiple regression model. RESULTS: Thirty-four patients were enrolled and treated by the undergraduate students. The mean OIDP value (global absolute score), representing the severity and frequency of the impacts, decreased from 26.2 to 12 after treatment. The mean percentage of impact, representing the number dimensions affected by oral health (global percent score), was reduced from 13% to 6%. However, no association between the number of treated teeth and post-treatment OIDP score was observed after adjusting for age, sex, and baseline OIDP score. CONCLUSION: Nonsurgical periodontal treatment performed by undergraduate dental students improved the oral health-related quality of life of periodontal patients, although no statistically significant association was found between the extent of periodontal treatment and the final OIDP score.

Spanish Dentists' Awareness, Knowledge, and Practice Regarding COVID-19: A Multiple Regression Analysis.

INTRODUCTION: During the first months of the coronavirus disease 2019 (COVID-19) pandemic, Spain had the highest mortality rate and the second-highest infection rate in the world. OBJECTIVE: To analyze the occupational situation of dentists, hygienists, and dental auxiliary staff during the peak of the pandemic, after the state of alarm was declared in Spain, and when the state of alarm was declared. In addition, a possible relationship between the geographical distribution of infected people and the availability of individual protection systems was investigated. MATERIAL AND METHODS: A cross-sectional questionnaire was answered by 6470 dentists and dental staff via WhatsApp and social media. RESULTS: A total of 1 in 4 dental professionals ceased working completely. Of those that kept working, 25.28% of dentists and 19.61% of hygienist-auxiliary were equipped with filtering face piece (FFP) 2 masks (P < .05), and 61.8% complied with the official protection recommendations set by the General Council of Dentists of Spain. Nearly 59.4% of respondents had symptoms, but only 1.5% of dentists were tested, with 14% of dentists in isolation at the time of response. Overall, it is suggested that 10% of dental professionals may have been in direct contact with the coronavirus. CONCLUSIONS: Direct contact of Spanish dental health professionals with severe acute respiratory syndrome coronavirus disease 2 (SARS CoV-2) has been high during the most active phase of the pandemic. Dental professionals did not have personal protective equipment (PPE) necessary to care for patients, a situation that justified the reduction in scheduled dental care and only emergencies being treated. The Spanish geographical regions with the highest number of contagions had the least amount of individual protective resources (FFP2 and FFP3 masks).

Peri-implant radiographic bone level and associated factors in Spain.

OBJECTIVES: To evaluate radiographic bone level (RxBL) at dental implants and its associated factors in Spain. MATERIAL AND METHODS: This cross-sectional study was performed by a network of sentinel dentists from regions of Spain. RxBL was defined as the distance from the implant shoulder to the first clearly visible contact between the implant surface and the bone. Radiographic measurements were performed by two trained and experienced periodontists. Implant and patient data were also collected. Descriptive, bivariate, discriminative and multivariate analyses were done. RESULTS: A total of 49 sentinel dentists provided data 275 patients. Mean RxBL from 474 implants (5-13 years) was 1.87 mm (range: 0.00-13.17 mm). Statistically significant associations between RxBL and clinical output variables (bleeding on probing, oedema, plaque, probing depth, suppuration, keratinized tissue) were found. In the multiple regression analysis, statistically significant associations for RxBL were found for smoking habit, implant diameter, years of follow-up and type of prosthesis (p < 0.01). CONCLUSIONS: Peri-implant RxBL ranged from 0 to 13.17 mm. It was significantly associated with clinical output variables and with some potentially predictor variables, at patient- (smoking >10 cigarettes/day) and implant- (diameter, years of follow-up, Toronto bridge) levels.

Hyaluronic acid reduces inflammation and crevicular fluid IL-1ß concentrations in peri-implantitis: a randomized controlled clinical trial.

PURPOSE: This study investigated the effects of hyaluronic acid (HA) on peri-implant clinical variables and crevicular concentrations of the proinflammatory biomarkers interleukin (IL)-1ß and tumor necrosis factor (TNF)-α in patients with peri-implantitis. METHODS: A randomized controlled trial was conducted in peri-implantitis patients. Patients were randomized to receive a 0.8% HA gel (test group), an excipient-based gel (control group 1), or no gel (control group 2). Clinical periodontal variables and marginal bone loss after 0, 45, and 90 days of treatment were assessed. IL-1ß and TNF-α levels in crevicular fluid were measured by enzyme-linked immunosorbent assays at baseline and after 45 days of treatment. Clustering analysis was performed, considering the possibility of multiple implants in a single patient. RESULTS: Sixty-one patients with 100 dental implants were assigned to the test group, control group 1, or control group 2. Probing pocket depth (PPD) was significantly lower in the test group than in both control groups at 45 days (control 1: 95% CI, -1.66, -0.40 mm; control 2: 95% CI, -1.07, -0.01 mm) and 90 days (control 1: 95% CI, -1.72, -0.54 mm; control 2: 95% CI, -1.13, -0.15 mm). There was a trend towards less bleeding on probing in the test group than in control group 2 at 90 days (P=0.07). Implants with a PPD ≥5 mm showed higher levels of IL-1ß in the control group 2 at 45 days than in the test group (P=0.04). CONCLUSIONS: This study demonstrates for the first time that the topical application of a HA gel in the peri-implant pocket and around implants with peri-implantitis may reduce inflammation and crevicular fluid IL-1ß levels. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03157193.

Efficacy of dental floss with ellipsoidal knots vs conventional dental floss for plaque removal: A split-mouth randomized trial.

OBJECTIVES: To compare clinical efficacy for plaque removal between dental floss with soft ellipsoidal knots and conventional floss. MATERIALS AND METHODS: We studied 33 university students (29 females and 4 males, 13 of them undergraduate/postgraduate students of dentistry), including regular and sporadic (less once/wk) users of dental floss, with interproximal spaces ≤1 mm, who used floss with and without knots in a randomized manner following a split-mouth design. The Modified Navy Plaque Index (RMNPI) by Rustogi et al. was applied to determine the total removed plaque (TPI) and that removed in the gingival area (GPI) and interproximal spaces (IPI). RESULTS: The reduction in GPI was greater with the knotted vs conventional floss in all cases (14.77 ± 12.38; 64.79% vs 17.38 ± 13.66; 57.51%) and especially among no floss users (12.469 ± 10.98; 68.02% vs 15.833 ± 11.88; 58.55%). No statistically significant difference between floss types was found in TPI and IPI (globally or by floss utilization frequency) or in the mean GPI of floss users. CONCLUSION: Floss with ellipsoidal knots showed similar efficacy to remove plaque in patients with less experience of flossing (but without statistically significant differences) compared with flossing themselves with conventional floss, and it may be an optimal solution for patients starting to use dental floss and for those with a lesser or only sporadic history of floss utilization.