Influence of artificial aging and ZrO2 nanoparticle-reinforced repair resin on the denture repair strength

Background: The purpose of this study was to evaluate the effect of aging process on the tensile strength (TS) of repaired acrylic denture base using ZrO2 nanoparticles (nano-ZrO2)-reinforced autopolymerized resin. Material and Methods: A total of 240 heat-polymerized acrylic resin specimens (n=10) were prepared and sectioned creating 2 mm-repair-gap. Autopolymerized acrylic resin, pure and modified with 2.5, 5, and 7.5wt% nano-ZrO2were used for specimens repair. TS of repaired specimens were measured using the universal testing machine af-ter water immersion at 37oC for 2, 7 and 30 days. At each time interval, half the immersed specimens underwent thermo-cycling aging process (5000 cycles at 5/55°C) before TS testing. One-way ANOVA and Tukey-Kramer multiple-comparison tests were used for data analysis at ?=0.05. Results: Aging process for all groups showed significant differences in TS between unreinforced and nano-ZrO2reinforced groups (p<0.05). Within immersed nano-ZrO2-reinforced specimens, 5% group immersed for 30-days showed the highest significant TS value (p<0.05). With regards to thermocycling, 5% group showed the highest TS values after 2-days and 30-days groups while after 7-days, significant differences were found between 2.5% group and 5% and 7.5% groups (p?0.05). SEM images analysis displayed the ductile fracture type for nano-ZrO2reinforced groups.Conclusions: In summary, 5.0%-nano-ZrO2 addition to repair resin showed an improvement in tensile strength of repaired acrylic resin with different aging processes

The effect of nanodiamonds on candida albicans adhesion and surface characteristics of PMMA denture base material : an in vitro study

Candida albicans&nbsp;is the main causative pathogen of denture stomatitis, which affects many complete denture patients. Objective: To evaluate the effect of different concentrations of nanodiamonds (NDs) added to polymethyl methacrylate (PMMA) denture base material on&nbsp;Candida albicans&nbsp;adhesion as well as on surface roughness and contact angle. Methodology: Acrylic resin specimens sized 10×10×3 mm3&nbsp;were prepared and divided into four groups (n=30) according to ND concentration (0%, 0.5%, 1%, 1.5% by wt). Surface roughness was measured with a profilometer, and the contact angle with a goniometer. The effect of NDs on&nbsp;Candida albicans&nbsp;adhesion was evaluated using two methods: 1) slide count and 2) direct culture test. Analysis of variance (ANOVA) and Tukey's post hoc test were used in the statistical analyses. Results: Addition of NDs decreased the&nbsp;Candida albicans&nbsp;count significantly more than in the control group (p&lt;0.05), with a lowest of 1% NDs. Addition of NDs also significantly decreased the surface roughness (p&lt;0.05), but the contact angle remained the same. Incorporation of NDs into the PMMA denture base material effectively reduced&nbsp;Candida albicans&nbsp;adhesion and decreased surface roughness. Conclusion: PMMA/NDs composites could be valuable in the prevention of denture stomatitis, which is considered one of the most common clinical problems among removable denture wearers

The effect of nanodiamonds on candida albicans adhesion and surface characteristics of PMMA denture base material - an in vitro study

Candida albicans is the main causative pathogen of denture stomatitis, which affects many complete denture patients. Objective: To evaluate the effect of different concentrations of nanodiamonds (NDs) added to polymethyl methacrylate (PMMA) denture base material on Candida albicans adhesion as well as on surface roughness and contact angle. Methodology: Acrylic resin specimens sized 10×10×3 mm3 were prepared and divided into four groups (n=30) according to ND concentration (0%, 0.5%, 1%, 1.5% by wt). Surface roughness was measured with a profilometer, and the contact angle with a goniometer. The effect of NDs on Candida albicans adhesion was evaluated using two methods: 1) slide count and 2) direct culture test. Analysis of variance (ANOVA) and Tukey’s post hoc test were used in the statistical analyses. Results: Addition of NDs decreased the Candida albicans count significantly more than in the control group (p<0.05), with a lowest of 1% NDs. Addition of NDs also significantly decreased the surface roughness (p<0.05), but the contact angle remained the same. Incorporation of NDs into the PMMA denture base material effectively reduced Candida albicans adhesion and decreased surface roughness. Conclusion: PMMA/NDs composites could be valuable in the prevention of denture stomatitis, which is considered one of the most common clinical problems among removable denture wearers.</p

Effects of Goat Manure Fertilization on Grain Nutritional Value in Two Contrasting Quinoa (Chenopodium quinoa Willd.) Varieties Cultivated at High Altitudes

In this study, the effects of goat manure fertilization (2, 4, 8, and 12 Tn/ha) on the grain yield, organic compounds, and mineral composition of two quinoa varieties (CICA-17 and Regalona Baer) were evaluated under field conditions in Northwest Argentina. The results indicate that fertilization improved the quinoa grain yield and total protein content. Low manure doses positively affected the fatty acid (FA) profile, and significant changes were determined for the monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acid contents of CICA-17 and on the saturated fatty acid (SFA) contents of R. Baer seeds. The amino acid contents were positively affected in CICA-17 and negatively in R. Baer. Soluble sugars (glucose, fructose, and sucrose), major elements (K, Si, P, Mg, Ca, and Na), minor elements (Fe, Mn, Al, Zn, and Cu), and ultratrace elements (Cr and Li) were detected and discussed in terms of their impact on human nutrition and health. Conclusively, manure addition affected some essential amino acids, the desaturase activity, the n6:n3 and SFA/UFA ratios, the atherogenic index, soluble sugars, and mineral content, and the fatty acid metabolism of each variety was differently affected, especially the C16 and C18 desaturase activity, which responded differently to various manure doses. Manure addition is a promising alternative to improve the nutritional quality and functionality of quinoa grains, but the response is not linear.EEA FamailláFil: González, Juan A. Fundación Miguel Lillo. Instituto de Ecología, Comportamiento y Conservación; ArgentinaFil: Yousif, Sawsan K.M. Al-Baha University. College of Arts and Science in Baljurashi. Department of Chemistry; Arabia SauditaFil: Erazzu, Luis Ernesto. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Erazzu, Luis Ernesto. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Martinez Calsina, Luciana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: Lizarraga, Emilio. Fundación Miguel Lillo. Instituto de Fisiología Animal; ArgentinaFil: Lizarraga, Emilio. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Omer, Rihab M. Al-Baha University. College of Arts and Science in Baljurashi. Department of Chemistry; Arabia SauditaFil: Bazile, D. CIRAD, UMR SENS; FranciaFil: Bazile, D. University Paul Valery Montpellier 3. CIRAD, IRD; FranciaFil: Fernandez-Turiel, J.L. CSIC. Geosciences Barcelona; EspañaFil: Buedo, Sebastián E. Fundación Miguel Lillo. Instituto de Ecología, Comportamiento y Conservación; ArgentinaFil: Rejas, M. CSIC. Geosciences Barcelona; EspañaFil: Fontana, Paola Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: González, D.A. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Instituto de Bioprospección y Fisiología Vegetal (INBIOFIV); ArgentinaFil: González, D.A. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Bioprospección y Fisiología Vegetal (INBIOFIV); ArgentinaFil:Oviedo, A. Fundación Miguel Lillo. Instituto de Fisiología Animal; ArgentinaFil: Alzuaibr, Fahad Mohammed. University of Tabuk. Faculty of Science. Department of Biology; Arabia SauditaFil: Al-Qahtani, Salem Mesfer. University of Tabuk. University College of Tayma. Biology Department; Arabia SauditaFil: Al-Harbi, Nadi Awad. University of Tabuk. University College of Tayma. Biology Department; Arabia SauditaFil: Ibrahim, Mohamed F.M. Ain Shams University. Faculty of Agriculture. Department of Agricultural Botany; EgiptoFil: Van Nieuwenhove, Carina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Van Nieuwenhove, Carina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos. Laboratorio de Ecofisiología Tecnológica; Argentin

Effects of Goat Manure Fertilization on Grain Nutritional Value in Two Contrasting Quinoa (Chenopodium quinoa Willd.) Varieties Cultivated at High Altitudes

In this study, the effects of goat manure fertilization (2, 4, 8, and 12 Tn/ha) on the grain yield, organic compounds, and mineral composition of two quinoa varieties (CICA-17 and Regalona Baer) were evaluated under field conditions in Northwest Argentina. The results indicate that fertilization improved the quinoa grain yield and total protein content. Low manure doses positively affected the fatty acid (FA) profile, and significant changes were determined for the monounsaturated (MUFA) and polyunsaturated (PUFA) fatty acid contents of CICA-17 and on the saturated fatty acid (SFA) contents of R. Baer seeds. The amino acid contents were positively affected in CICA-17 and negatively in R. Baer. Soluble sugars (glucose, fructose, and sucrose), major elements (K, Si, P, Mg, Ca, and Na), minor elements (Fe, Mn, Al, Zn, and Cu), and ultratrace elements (Cr and Li) were detected and discussed in terms of their impact on human nutrition and health. Conclusively, manure addition affected some essential amino acids, the desaturase activity, the n6:n3 and SFA/UFA ratios, the atherogenic index, soluble sugars, and mineral content, and the fatty acid metabolism of each variety was differently affected, especially the C16 and C18 desaturase activity, which responded differently to various manure doses. Manure addition is a promising alternative to improve the nutritional quality and functionality of quinoa grains, but the response is not linear

Evaluation of inhaled nitric oxide (iNO) treatment for moderate-to-severe ARDS in critically ill patients with COVID-19: A multicenter cohort study

Background: Inhaled nitric oxide (iNO) is used as rescue therapy in patients with refractory hypoxemia due to severe COVID-19 acute respiratory distress syndrome (ARDS) despite the recommendation against the use of this treatment. To date, the effect of iNO on the clinical outcomes of critically ill COVID-19 patients with moderate-to-severe ARDS remains arguable. Therefore, this study aimed to evaluate the use of iNO in critically ill COVID-19 patients with moderate-to-severe ARDS. Methods: This multicenter, retrospective cohort study included critically ill adult patients with confirmed COVID-19 treated from March 01, 2020, until July 31, 2021. Eligible patients with moderate-to-severe ARDS were subsequently categorized into two groups based on inhaled nitric oxide (iNO) use throughout their ICU stay. The primary endpoint was the improvement in oxygenation parameters 24 h after iNO use. Other outcomes were considered secondary. Propensity score matching (1:2) was used based on the predefined criteria. Results: A total of 1598 patients were screened, and 815 were included based on the eligibility criteria. Among them, 210 patients were matched based on predefined criteria. Oxygenation parameters (PaO2, FiO2 requirement, P/F ratio, oxygenation index) were significantly improved 24 h after iNO administration within a median of six days of ICU admission. However, the risk of 30-day and in-hospital mortality were found to be similar between the two groups (HR: 1.18; 95% CI: 0.77, 1.82; p = 0.45 and HR: 1.40; 95% CI: 0.94, 2.11; p= 0.10, respectively). On the other hand, ventilator-free days (VFDs) were significantly fewer, and ICU and hospital LOS were significantly longer in the iNO group. In addition, patients who received iNO had higher odds of acute kidney injury (AKI) (OR (95% CI): 2.35 (1.30, 4.26), p value = 0.005) and hospital/ventilator-acquired pneumonia (OR (95% CI): 3.2 (1.76, 5.83), p value = 0.001). Conclusion: In critically ill COVID-19 patients with moderate-to-severe ARDS, iNO rescue therapy is associated with improved oxygenation parameters but no mortality benefits. Moreover, iNO use is associated with higher odds of AKI, pneumonia, longer LOS, and fewer VFDs

Mandibular implant-supported overdentures: Prosthetic overview

Implant-supported overdentures are becoming the treatment of choice for the completely edentulous mandible. They significantly improve the quality of life in edentulous patients. For this review article, the literature was searched to identify pertinent studies. No meta-analysis was conducted because of high heterogeneity within the literature. Accordingly, in this review article, the author provides an update on implant-supported mandible overdentures with regard to the number of implants, type of loading, stress–strain distribution, mode of implant-to-denture attachment, occlusal considerations and complications

The minimum inhibitory concentration of different candidal disinfecting agents

Purpose: Despite the availability of a large number of commercial denture cleansing products, only a few are used by wearers of dentures. This may be due to negligence on the part of the wearers of dentures and or the high cost of the products. We, therefore, felt inspired to study the antifungal effect of different materials usually available in the kitchen. Materials and Methods: One hundred and sixty resin acrylic samples were prepared and divided into three groups of 50 samples each and immersed into variable concentrations of: Sodium chloride (Group I), Sodium bicarbonate (Group II), and vinegar (Group III). In addition, 10 samples were immersed into water as a control group (Group IV). Minimum inhibitory concentration and the minimum immersion time needed were studied for each group. Results: The solutions were only found to be effective against Candida albicans in concentrations higher than 50 ml/200 ml, 10 g/200 ml and 5 g/200 ml of vinegar, sodium bicarbonate and sodium chloride respectively. The same concentrations were more effective when acrylic resin plates were immersed for 8 hours rather than 1 hour (P < 0.05). Conclusion: Sodium chloride, sodium bicarbonate and vinegar are not strong enough as denture cleansing agents in low concentrations. However, high concentrations used for 8 hours might be helpful for the user of dentures

Reliability of Bonded MOD Restorations in Maxillary Premolars: Microleakage and Cusp Fracture Resistance

Svrha: Ovo in vitro istraživanje provedeno je na maksilarnim pretkutnjacima kako bi se procijenili mikropropusnost i otpornost kvržica na frakturu. Materijal i metode: Uzorci su se sastojali od adhezivno vezanih direktnih ispuna i keramičkih inlaya (ranije pripremljenih umetaka), a ispitani su nakon umjetno simuliranog starenja s pomoću termičkog i okluzalnog cikličkog opterećenja. Za to je uporabljeno 66 tek izvađenih maksilarnih pretkutnjaka, a bilo ih je po šest u svakoj skupini. Zatim su izrađeni standardizirani MOD - kaviteti i podijeljeni u dvije glavne skupine, ovisno o smještaju gingivne stijenke i to jedan milimetar iznad (A1) ili jedan milimetar (A2) ispod cementno-caklinskog spoja (CCS-a). Nakon toga uzorci su podijeljeni u dvije podskupine: Z 250 kompozit za direktno postavljanje i IPS Empress – staklokeramički ispun zatvoren kompozitnim cementom Variolink II. Skupina intaktnih zuba te dvije skupine s prepariranim kavitetima A1 i A2 služile su kao kontrola. Restaurirani zubi uloženi su zatim u blokove od akrilatne smole i stavljeni u stroj za cikličko-termičko i mehaničko opterećenje. Mikropropusnost je procijenjena metodom ocjenjivanja prodora boje pod Zeissovim stereomikroskopom. Rezultati: Otpornost kvržica na frakturu ispitana je vertikalnim opterećenjem do pucanja. Srednje vrijednosti testa frakturnog opterećenja i mikropropusnosti analizirane su statistički. Proučavani ispuni nisu pokazali veću razliku u adaptaciji ispuna na caklinskim rubovima. Keramički ispuni bolje su brtvili te snažnije ojačali strukturu zuba nego kompozitni, posebice na necaklinskim rubovima. Priprema kaviteta dosta je oslabila strukturu. Zaključak: Ispuni su samo djelomice nadoknadili učinak slabljenja zbog njegove preparacije. Poboljšanje adhezivnih ispuna, tj. adaptacija i pojačanje strukture zuba, stalan su izazov u restaurativnoj dentalnoj medicini.Purpose: This in vitro investigation was performed to assess microleakage and cusp fracture resistance of maxillary premolars specimens involving composite resin direct restorations and ceramic inlay restorations. Material and methods: Specimens were tested after artificial aging provoked by thermal and occlusal load cycling. For that purpose, 66 extracted maxillary premolars were used with six premolars in each study group. Standardized MOD cavities were prepared and classified into two main groups according to gingival-margins location either 1mm above (A1) or 1 mm below (A2) the CEJ. Specimens were subdivided into two subgroups: Z250 composite resin direct restorations and IPS Empress glass ceramic restorations cemented with Variolink II resincement. Group of intact teeth specimens and two groups of A1 and A2 type prepared but not restored teeth served as control groups. Restored teeth were mounted in acrylic-resin blocks before loading and thermocycling. Microleakage was assessed by examining dye penetration scores under Zeiss-stereomicroscope. Cusp fracture resistance was performed using vertical static loading until failure. The fracture-load test mean values and microleakage results were statistically analyzed. Results: Investigated restorations showed insignificant difference in adaptation at enamel margins. Ceramic restorations showed better sealability and tooth structure reinforcing effects than composite restorations, especially at non-enamel margins. Conclusions: Cavity preparation produced significant weakening effect. Restorations just partly compensated weakening effect of cavity preparation. Upgrading the performance of adhesive restorations in terms of adaptation and tooth structure reinforcement poses a continuing challenge to restorative dentistry