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1.
BMC Oral Health ; 24(1): 543, 2024 May 09.
Artículo en Inglés | MEDLINE | ID: mdl-38724952

RESUMEN

BACKGROUND: In complex teeth like maxillary premolars, endodontic treatment success depends on a complete comprehension of root canal anatomy. The research on mandibular premolars' root canal anatomy has been extensive and well-documented in existing literature. However, there appears to be a notable gap in available data concerning the root canal anatomy of maxillary premolars. This study aimed to explore the root canal morphology of maxillary premolars using cone-beam computed tomography (CBCT) imaging, considering age and gender variations. METHODS: From 500 patient CBCT scans, 787 maxillary premolar teeth were evaluated. The sample was divided by gender and age (10-20, 21-30, 31-40, 41-50, 51-60, and 61 years and older). Ahmed et al. classification system was used to record root canal morphology. RESULTS: The most frequent classifications for right maxillary 1st premolars were 2MPM1 B1 L1 (39.03%) and 1MPM1 (2.81%), while the most frequent classifications for right maxillary 2nd premolars were 2MPM1 B1 L1 (39.08%) and 1MPM1 (17.85%). Most of the premolars typically had two roots (left maxillary first premolars: 81.5%, left maxillary second premolars: 82.7%, right maxillary first premolars: 74.4%, right maxillary second premolars: 75.7%). Left and right maxillary 1st premolars for classes 1MPM1 and 1MPM1-2-1 showed significant gender differences. For classifications 1MPM1 and 1MPM1-2-1, age-related changes were seen in the left and right maxillary first premolars. CONCLUSION: This study provides novel insights into the root canal anatomy of maxillary premolars within the Saudi population, addressing a notable gap in the literature specific to this demographic. Through CBCT imaging and analysis of large sample sizes, the complex and diverse nature of root canal morphology in these teeth among Saudi individuals is elucidated. The findings underscore the importance of CBCT imaging in precise treatment planning and decision-making tailored to the Saudi population. Consideration of age and gender-related variations further enhances understanding and aids in personalized endodontic interventions within this demographic.


Asunto(s)
Diente Premolar , Tomografía Computarizada de Haz Cónico , Cavidad Pulpar , Maxilar , Humanos , Diente Premolar/diagnóstico por imagen , Diente Premolar/anatomía & histología , Masculino , Femenino , Adolescente , Maxilar/diagnóstico por imagen , Maxilar/anatomía & histología , Cavidad Pulpar/diagnóstico por imagen , Cavidad Pulpar/anatomía & histología , Adulto , Arabia Saudita , Persona de Mediana Edad , Niño , Estudios Transversales , Adulto Joven , Factores Sexuales , Factores de Edad
2.
Scientifica (Cairo) ; 2024: 9990562, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38690100

RESUMEN

Background: As people live longer, there is an increasing need for hard tissue regeneration and whole-tooth regeneration. Despite the advancements in the field of medicine, the field of regenerative dentistry is still challenging due to the complexity of dental hard tissues. Cross-disciplinary collaboration among material scientists, cellular biologists, and odontologists aimed at developing strategies and uncovering solutions related to dental tissue regeneration. Methodology. A search of the literature was done for pertinent research. Consistent with the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) 2020 Statement, the electronic databases looked at were PubMed, Science Direct, Scopus, and Google Scholar, with the keyword search "hard dental tissue regeneration." Results: Database analysis yielded a total of 476 articles. 222 duplicate articles have been removed in total. Articles that have no connection to the directed regeneration of hard dental tissue were disregarded. The review concluded with the inclusion of four studies that were relevant to our research objective. Conclusion: Current molecular signaling network investigations and novel viewpoints on cellular heterogeneity have made advancements in understanding of the kinetics of dental hard tissue regeneration possible. Here, we outline the fundamentals of stem hard dental tissue maintenance, regeneration, and repair, as well as recent advancements in the field of hard tissue regeneration. These intriguing findings help establish a framework that will eventually enable basic research findings to be utilized towards oral health-improving medicines.

3.
J Fluoresc ; 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38683267

RESUMEN

To explore the possible impact of 2-Phenylbenzimidazole-5-sulfonic acid (PBSA) on the function of a sunscreen, in this work we investigate the binding of copper metal ions (Cu2+) to PBSA. Due to the existence of an intrinsic interaction phenomenon between Cu2+ ions and PBSA molecules, the photoluminescence (PL) quenching arises owing to the charge transfer from PBSA to Cu2+ ions. The mechanism of fluorescence quenching is probed experimentally following excitation at 306 nm by evaluating various quenching parameters with the help of the Stern-Volmer plot. Through the assessment of the values of the Stern-Volmer constant ( K SV = 45.2 M - 1 ) and bimolecular quenching rate constant ( k q = 0.77 × 10 10 M - 1 . s - 1 ), it is deduced that the dynamic mode of PL quenching is operative between PBSA and Cu2+ ions. We evaluate the number of binding sites (n = 1) that advocate the presence of a single binding site in PBSA for Cu2+ ions. The numerical value of standard Gibbs free energy change, Δ G o ~ -27.485 kJ.mol-1 implies the spontaneous binding between Cu2+ ions and PBSA molecules. The results obtained give an insight into the mechanism of metal-induced PL quenching of water soluble PBSA sunscreen.

4.
J Clin Pediatr Dent ; 48(2): 64-71, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38548634

RESUMEN

Tooth avulsion is a frequently encountered dental emergency. Children are commonly reported group due to frequent sports activities, trauma, accidents and falls. Prompt emergency management is vital for long term success and to avoid morbidity. The study was aimed to assess the understanding of intern dentists about the emergency handling of avulsed teeth cases as mostly they are first responders among health care personnel. In this study a fourteen-item questionnaire with predefined responses was shared as online Google survey form with intern dentists of 5 different dental teaching hospitals of Islamabad, Pakistan. The duration of the study was 6 months (01 March 2022 to 31 August 2022). The questions were intended to collect personal information and to check level of knowledge and awareness about the management of avulsed tooth among the dental interns. The data was analyzed by statistical methods and is presented through tables and descriptive methods. In total, 152 participants completed the shared questionnaire. The vast majority (71%) of them were aware of the initial management of avulsed teeth, 49% were aware of the ideal transport medium for an avulsed tooth, (43%) were aware of the critical time for successful replantation, while (62%) had knowledge of the multiple factors responsible for the outcome of the tooth replantation. For majority of the statements, female participants had better knowledge as compared to their male counterparts. Statistically significant difference was noted for the statement "If you found the knocked-out tooth and it is dirty what will be your initial approach?" with female participants having better knowledge as compared to the male (p value = 0.005). Based on our study results, generally dental interns are well-informed but still lack expected level of awareness regarding the proper management protocol for avulsed tooth. Hence, improvement is needed regarding the effective handling of avulsed teeth cases.


Asunto(s)
Avulsión de Diente , Niño , Humanos , Masculino , Femenino , Avulsión de Diente/terapia , Conocimientos, Actitudes y Práctica en Salud , Reimplante Dental/métodos , Estudios Transversales , Encuestas y Cuestionarios , Odontólogos
5.
PeerJ ; 12: e16863, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38313036

RESUMEN

Background: Caries risk (CR) assessment tools are used to properly identify individuals with caries risk and to improve preventive procedures and programs. A tool such as CAMBRA determines the precise protective factors of caries and identifies an individual's specific therapeutic intervention. The purpose of this study was to assess the caries risk using the CAMBRA protocol among the general population of Pakistan. Methods: This multicentre analytical study was conducted in ten dental hospitals in different provinces of Pakistan and the caries risk assessment was carried out using a questionnaire that was designed using the Caries Management by Risk Assessment (CAMBRA) protocol. All 521 participants were intra-orally examined to assess oral hygiene status and the presence of disease. Multiple logistic regression test was performed for analysis. Results: A higher number of participants (61.2%) were found to be in the moderate risk category of caries risk assessment. The males are 51% less likely to have caries compared to the females (AOR = 0.49, P = 0.081). The majority of participants (71.3%) had one or more disease indicators, with white spots and visible cavities. Those with visible, heavy plaque were 13.9 times more likely to have caries compared to those without (AOR = 13.92, P < 0.001). Those using calcium and phosphate during the last 6 months were 90% less likely to have caries compared to those not using them (AOR = 0.10, P < 0.001). There was no significant interaction between all eight risk factors retained in the final model (P > 0.05), the Hosmer and Lemeshow Test P < 0.001, classification accuracy = 87.1%, and AUC = 91.2%. Conclusion: The caries risk among the general population of Pakistan is moderate, with significant variation among age groups, education levels, and socioeconomic status.


Asunto(s)
Susceptibilidad a Caries Dentarias , Caries Dental , Masculino , Femenino , Humanos , Pakistán/epidemiología , Medición de Riesgo/métodos , Factores de Riesgo , Caries Dental/diagnóstico , Estudios Multicéntricos como Asunto
6.
Scientifica (Cairo) ; 2024: 9918914, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38225940

RESUMEN

Background: Soft denture lining materials act as a cushion between the denture base and tissues. Alongside having many advantages, its main problem is candida growth due to its rubbery and porous texture. Many interventions have been performed to halt the growth of candida within soft lining materials such as the use of antifungal therapy and strict oral and denture hygiene but there are consequences such as recurrence, drug resistance, and toxicity related to these interventions. Since natural agents such as aloe vera and chitosan have been proven to have antibacterial and antifungal properties with minimum adverse effects, this study aimed to study the effectiveness of chitosan and aloe vera powders incorporated within denture soft lining materials against candida adherence. Methodology. A total of 60 soft-lining material samples were prepared that were equally divided into three groups, viz., group 1 (chitosan incorporation), group 2 (aloe vera incorporation), and group 3 (control). Candida was obtained from the microbiology lab to form a candidal suspension, diluted in 0.9% NaCl to match the McFarland standard bacteriologic solution. Samples were incubated at 37°C for 24 hours in test tubes containing 100 mL of the candidal suspension and 9.9 mL of the previously prepared Sabouraud dextrose agar. Crystal violet stain was used to stain the adhering cells by fixing them with methanol 80%. For each sample, the adhering candida cells were counted on three standard fields by using an inverted light microscope, and the mean of those fields was recorded. Results: The mean value for samples containing aloe vera was 41.15, while the mean values for samples containing chitosan and the control group were 16.05 and 79.1, respectively. Of all the three groups, aloe vera powder had a significant efficacy against candida growth as compared to the chitosan and control groups (P value = 0.001). Conclusion: Both herbal agents were effective against candida growth. In comparison, aloe vera was more effective against candida growth compared to chitosan.

7.
Artículo en Inglés | LILACS, BBO - Odontología | ID: biblio-1529145

RESUMEN

Abstract Objective: To identify the factors affecting clinical performance among dental students and to help addressing these problems. Material and Methods: A cross-sectional study in which students of third and final year of dentistry participated. Data was collected from June 2022 till September 2022. Data was collected from the third and final year dental students of both public and private dental colleges within the Pakistan using a purposive sampling technique. Results: A total of 372 dental students participated in this study. Thirty eight (31.9%) students belonged to third year while 81 (68.1%) were final year students from government college. For the private dental college, 121 (47.8%) were third year students while 132 (52.2%) were final year students. Majority of the participants were males from both the colleges. 42.9% of government dental students and 26.5% of private dental students agreed on well-preparedness of clinical instructors. 5.5% from private and 21.0% from government dental colleges agreed that adequate personal protective equipment were present in clinical departments. Conclusion: From this study, it is concluded that there should be focus more focus on the factors to enhance clinical skills, supervision of students in clinical practice to help addressing the problems faced during learning and performance in a clinical environment, to produce self-confident, motivated, knowledgeable, skillful and a professional dental graduates.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Estudiantes de Odontología , Salud Laboral , Evaluación del Rendimiento de Empleados , Pakistán/epidemiología , Estudios Transversales/métodos , Encuestas y Cuestionarios , Interpretación Estadística de Datos , Aprendizaje Basado en Problemas
8.
Artículo en Inglés | LILACS, BBO - Odontología | ID: biblio-1535009

RESUMEN

ABSTRACT Objective: To assess the prevalence of burnout among dental students of public and private institutions in Khyber Pakhtunkhwa and Punjab, Pakistan. Material and Methods: A cross-sectional descriptive survey was conducted at five public and private dental institutions from June 2021 to May 2022. A validated twelve-item closed-ended Burnout Clinical Subtype Questionnaire was distributed among the dental students of two private and two public institutes in Pakistan. The research questions focused on demographic information and students' academic experiences. Data analysis is presented through tables and descriptive methods. Results: A total of 274 dental undergraduate students - second (42.3%), third (35.4%), and final (22.3%) academic year participated in this study. The mean age of the respondents was 21.9, with the range of 20-26 years. Most participants were females (74.1%) compared to the males (25.9%). The findings for burnout syndrome among dentistry students and students in the private and public sectors were not significant. Conclusion: In the current study, burnout levels among dental undergraduates, both private and public, were low.


Asunto(s)
Humanos , Masculino , Femenino , Adulto , Facultades de Odontología , Estrés Psicológico/prevención & control , Estudiantes de Odontología , Agotamiento Profesional/prevención & control , Pakistán/epidemiología , Estudios Transversales/métodos , Encuestas y Cuestionarios , Estadísticas no Paramétricas
9.
Cureus ; 15(10): e47390, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38022006

RESUMEN

Background During the COVID-19 pandemic, universities worldwide pivoted to distance education, primarily online, using various blended learning tools. In the contemporary era, characterized by widespread high-speed internet and the ubiquity of social media (SM), SM has become an essential tool, especially among students. This study aimed to assess the perception, impact, and preferences of various SM platforms for learning among health sciences students in the post-COVID-19 era. Methodology The study was conducted at constituent colleges of Jouf University and Northern Border University between January and June 2022. Responses from 560 students were assessed using a self-administered, pre-validated questionnaire comprising 31 questions. These questions addressed students' perceptions, preferences, and learning modes derived from SM. Descriptive and inferential statistics evaluated the influence of SM on student learning. Results On average, students spent 3.18 hours daily on SM. YouTube (41.1%) and Instagram (37.1%) emerged as the most preferred platforms for learning. A significant 86.4% of students utilized SM for accessing subject-related texts and watching related videos. Moreover, 78.6% believed that SM platforms enhanced their subject knowledge following lectures. Logistic regression analysis indicated maximum learning benefits for students who used SM between two to three hours daily. Conclusion Social media platforms, when used judiciously, can enhance the learning experience for health sciences students in the post-COVID era. While offering opportunities to acquire new knowledge and skills, care must be taken to prevent misuse, abuse, or related health hazards.

10.
Photochem Photobiol ; 2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-37961822

RESUMEN

Apart from biocompatibility, ZnO quantum dots (QDs) are considered to be an efficient luminescence material due to their low cost and high redox potential. Here, we report the synthesis of ZnO QDs by using five different functionalizing ligands like mercaptoacetic acid (MAA), 3-mercaptopropionic acid (MPA), octadecene (ODE), ethylene glycol (EG), and oleyl amine (OLA) and fabricate their assemblies with graphene oxide (GO). We investigate the role of functionalizing ligands as a surface modifier of ZnO QDs for their attachment to GO. The steady-state photoluminescence (SSPL) and time-resolved photoluminescence (TRPL) analyses demonstrate the photoluminescence (PL) quenching of ZnO QDs in ZnO QDs-GO assembly. The highest reduction in PL intensity is observed with ZnO QDs-GO assembly with EG as a surface functionalizing ligand. Cyclic voltammetry (CV) analysis confirms the feasibility of charge transfer from ZnO QDs to the GO. The maximum (79.43%) charge transfer efficiency (ECT ) is observed in the case of ZnO-MAA-GO as compared to other assemblies. This means the thiol group-containing ligands facilitate charge transfer as compared to hydroxyl and amine group ligands. This leads to the conclusion that charge transfer in ZnO QDs-GO assemblies depends strongly on the nature of surface ligands.

11.
Medicina (Kaunas) ; 59(11)2023 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-38003997

RESUMEN

Background and Objectives: This review focuses on reviewing studies from the literature regarding the effects of deep margin elevation on the surrounding periodontium. Materials and Methods: A review of the literature was carried out using the following online databases: Embase, The Cochrane Library, MEDLINE-PubMed and Google Scholar. Our search was limited to articles from 2010 to 2023. The search terms consisted of keywords and MeSH terms, which were 'deep margin elevation', 'coronal margin relocation', 'periodontium' and 'periodontal tissues'. The literature was searched thoroughly by two reviewers. Initially, the titles of the articles were extracted. After removing irrelevant and duplicate articles, abstracts were assessed for relevant articles. Finally, the reviewers analyzed full-text articles. Results: A total of twelve articles, including one randomized clinical trial, three systematic reviews, two prospective cohort, three case series, one a clinical study, one pilot study and one a retrospective study, were selected and analyzed. Conclusions: The review suggests potential benefits of Deep Margin Elevation (DME) over surgical crown lengthening due to reduced invasiveness, yet conclusive effects on periodontal tissue remain unclear, warranting further studies on clinical parameters and inflammatory biomarkers.


Asunto(s)
Ligamento Periodontal , Periodoncio , Humanos , Estudios Prospectivos , Proyectos Piloto , Estudios Retrospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto
12.
J Clin Pediatr Dent ; 47(4): 35-39, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37408344

RESUMEN

It is imperative to manage children with empathy and concern for their well-being in order to carry out any dental procedure smoothly. Owing to the inherent fear of dental operatory, behaviour management of children is an important aspect of pediatric dental care. Many techniques are available to help manage the behaviour of children. It is, however important to educate parents about these techniques and to get their cooperation for these techniques to be used on their children.This study aimed to familiarize the parents with non-pharmacological behavior management techniques and to determine the parental acceptance of such techniques in children seeking dental treatment in specialty care dental units. A total of 303 parents were evaluated through online questionnaires in this research. They were shown videos of randomly selected non-pharmacologic behaviour management techniques including tell-show-do, positive reinforcement, modelling and voice control. Parents were asked to watch the videos and give their response on seven-items inquiring about their acceptance levels regarding the respective techniques. The responses were recorded on a Likert scales ranging from strongly disagree to strongly agree. According to parental acceptance score (PAS), positive reinforcement was the most accepted technique whereas voice control was the least acceptable technique. Majority of the parents were more receptive towards those techniques that involved a healthy and friendly communication between a dentist and the pediatric patient such as, positive reinforcement, tell show do and modelling. Most significantly the people having low socio-economic status (SES) in Pakistan were more acceptable of voice control than people with high SES.


Asunto(s)
Conducta Infantil , Restricción Física , Niño , Humanos , Estudios Transversales , Padres , Atención Odontológica
13.
J Clin Pediatr Dent ; 47(4): 80-85, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37408350

RESUMEN

Orthodontic treatment requires the cooperation of patients as well as orthodontists. Therefore, the aim of the study was to investigate and address the challenges and barriers orthodontists have in achieving the desired orthodontic results, as well as make recommendations for ways to address the stated problems and introduce new innovative technologies to the area of orthodontics. This qualitative study wasbased on the grounded theory. Twelve orthodontists participated in face-to-face interviews, which were primarily comprised of open-ended questions. Data analysis was carried out manually using the "by hand" method. Orthodontists between the age group of 29-42 were interviewed. The answers varied depending on the years of experience of the interviewees. Teenagers and boys were found to be most non-compliant with the treatment. The average treatment span ranged between 6 months for mild cases up to 3 years for severe orthodontic cases occurring most commonly in government hospitals. Patient compliance plays a major role in orthodontics. Poor oral hygiene maintenance, brackets breakage by patients, and missed appointments were the major concerns mentioned by participants and hindered getting the desired results. Patients' main worries were related to the cost of therapy, premolar extractions, the length of treatment, and the possibility of relapse. Patient counseling and reinforcement at the start of the treatment can help to overcome the challenges and barriers in orthodontics since patient motivation is a very important factor in obtaining the desired results. It is recommended to conduct more training sessions for the orthodontists in order to introduce them to new technological paradigms.


Asunto(s)
Ortodoncia , Masculino , Humanos , Adulto , Niño , Adolescente , Ortodoncistas , Atención Odontológica , Encuestas y Cuestionarios
14.
PeerJ ; 11: e15677, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37520257

RESUMEN

This study aims to formulate experimental vinylpolysiloxane (VPS) impression materials and compare their elastic recovery and strain-in-compressions with three commercial VPS materials (Aquasil, Elite, and Extrude). Five experimental materials (Exp), two hydrophobic (Exp-I and II) and three hydrophilic (Exp-III, IV and V) were developed. Exp 1 contained vinyl-terminated poly-dimethyl siloxane and a conventional cross-linking agent (poly methylhydrosiloxane), while Exp- II contained a novel cross-linking agent that is tetra-functional dimethyl-silyl-ortho-silicate (TFDMSOS). Exp III-V (hydrophilic materials) were formulated by incorporating different concentrations of non-ionic surfactant (Rhodasurf CET-2) into Exp II formulation. Measurement of elastic recovery and strain-in-compression for commercial and experimental materials were performed according to ISO4823 standard using the calibrated mechanical testing machine (Tinius Olsen). One-way analysis of variance (one-way ANOVA) and Tukey's post-hoc (HSD) test were used for statistical analysis and a p-value of ≤ 0.05 was considered significant. Exp-I has statistically similar values to commercial VPS. The Exp-II showed the highest elastic recovery, while % elastic recovery was reduced with the addition of the non-ionic surfactant (Rhodasurf CET-2). The % reduction was directly related to the concentration of Rhodasurf CET-2. In addition, Exp II had significantly higher strain-in-compression values compared to Exp-I and commercial materials. These values were further increased with the addition of a non-ionic surfactant (Rhodasurf CET-2) was added (Exp-III, IV and V).


Asunto(s)
Surfactantes Pulmonares , Siloxanos , Siloxanos/química , Tensoactivos/química , Ensayo de Materiales , Lipoproteínas , Materiales de Impresión Dental
15.
J Org Chem ; 88(15): 11056-11068, 2023 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-37462323

RESUMEN

A palladium-catalyzed direct C-H arylation of indolines at C-7 position has been achieved at near-ambient temperature. The reaction was carried out with aryltriazene as a stable aryl source and electron shuttle to sustainably release aryl radical in situ under the action of promoter, and pyrimidine as a detachable directing group for the synthesis of 7-arylindolines under oxidant- and ligand-free conditions. Notably, this catalytic system can also be applied to the direct and site-selective arylation of tetrahydroquinolines (C-8) and carbazoles (C-1).

16.
J Fluoresc ; 33(6): 2523-2529, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37314535

RESUMEN

In this article, we report the synthesis of graphene quantum dots (GQDs) by hydrothermal method and surface modified CdS quantum dots (QDs) via the colloidal method and the fabrication of their dyad. The CdS QDs functionalized by mercaptoacetic acid (MAA) attach to the GQDs via electrostatic interactions. Spectral overlapping between the emission spectrum of GQDs and the absorption spectrum of CdS QDs allows efficient Förster resonance energy transfer (FRET) from GQDs to the CdS QDs in the GQDs-CdS QDs dyads. The magnitude of FRET efficiency (E) and the rate of energy transfer (kE) assessed by the photoluminescence (PL) decay kinetics are ~61.84% and ⁓3.8 × 108 s- 1, respectively. These high values of FRET efficiency and energy transfer rate can be assigned to the existence of strong electrostatic interactions between GQDs and CdS QDs, which arise due to the presence of polar functionalities on the surface of both GQDs and CdS QDs. The understanding of energy transfer in the luminescent donor-acceptor FRET system is of significant importance and the practical implications of such FRET systems could overall improve the efficiency of photovoltaics, sensing, imaging and optoelectronic devices.

17.
RSC Adv ; 13(28): 19096-19105, 2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37362335

RESUMEN

In this article, we report the band gap tuning of ternary ZnCdS quantum dots (QDs) by varying the concentration of the capping ligand, mercaptoacetic acid (MAA). The functionalization of QDs leads to the control of their size and band gap due to the quantum confinement effect, causing blue shift in the absorption and photoluminescence (PL) spectra with a gradual change in the concentration of the capping ligand from 0.5 to 2.5 M. Ensulizole (2-phenylbenzimidazole-5-sulfonic acid) is an important organic ultraviolet (UV) filter that is frequently used in sunscreen cosmetics. An effective overlapping of the PL spectrum of ensulizole and the absorption spectrum of QDs with 2.5 M MAA is achieved. A formidable decrease in the PL intensity and the PL lifetime of ensulizole promotes an efficient Förster resonance energy transfer (FRET) from sunscreen ensulizole to the QDs. The magnitude of the FRET efficiency (E) is ∼70%. This very high value of E is the signature of the existence of a very fast energy transfer process from ensulizole to the MAA functionalized ZnCdS QDs. The dyad system consisting of ZnCdS QDs and ensulizole sunscreen can serve as a prototype model to develop a better understanding of the photochemistry of ensulizole and consequently the formulation of more efficient sunscreen cosmetics.

18.
Phys Chem Chem Phys ; 25(26): 17410-17419, 2023 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-37350276

RESUMEN

The combination of halide perovskite NCs with graphene to design heterostructures has proven to be a promising candidate for energy applications, optoelectronics, and photocatalysis. Efficient light energy absorption in perovskite NC-graphene heterostructures is of fundamental importance owing to their optoelectronic applications. A detailed understanding of the important process for device action, particularly interfacial charge transfer (CT), has thus far lingered subtly. This study describes the influence of the different surface functionalities of graphene on the CT dynamics in FAPbBr3 NCs attached to functionalized graphene heterostructures. Functionalized graphenes i.e., graphene oxide (GO) and amino acids (alanine (Ala), tyrosine (Tyr) and cysteine (Cys)) functionalized GO, were synthesized. By assembling the heterostructures of functionalized graphene with NCs, the quenching of photoluminescence (PL) of the FAPbBr3 NCs was observed. The photo-generated hole transfer from FAPbBr3 to functionalized graphene is responsible for PL quenching, which is supported by time-resolved photoluminescence (TRPL) and cyclic voltammetry (CV) analysis. Our study revealed that the rate of CT and charge transfer efficiency (ECT) strongly depend on the nature of the functionalizing moieties. The highest hole transfer efficiency for NC-functionalized graphene heterostructures was observed in the case of cysteine-functionalized GO (88.84%) and the lowest with GO (38.15%). This suggests that cysteine-functionalized graphene is the best hole acceptor amongst all functionalized graphenes. This study offers a method to regulate energetics and investigate the extent of hole transfer in perovskite NCs and functionalized graphene heterostructures. These findings tend to draw new directions to stimulate advance research regarding the fundamental understanding of hole transfer in surface-modified donor-acceptor heterostructures for light harvesting assemblies, especially solar cells.

19.
BMC Oral Health ; 23(1): 291, 2023 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-37189077

RESUMEN

BACKGROUND: The clinician should have complete knowledge of the normal anatomy of the root as well as complexities in the root canal configuration for a better outcome, as missed or improper handling of the canal system can lead to the failure of an entire endodontic procedure. The present study aims to assess the morphology of roots and canals in permanent mandibular premolars in the Saudi subpopulation with a new classification system. METHODS: The present study includes 1230 mandibular premolars (645 first premolars and 585-second premolars) from 500 CBCT images of the patients, including retrospective data. iCAT scanner system (Imaging Sciences International, Hatfield, PA, USA) was used to obtain the images; scanning of 8 × 8 cm images was performed at 120 KVp and 5-7 mA with a voxel size of 0.2 mm. The new method of classification presented by Ahmed et al. 2017 was used to record and classify the root canal morphology, followed by recording the differences regarding the age and gender of the patients. Comparison of canal morphology in lower permanent premolars and its association with gender and age of the patients was done by Chi-square test/ Fisher exact test; the significance level was set at 5% (p ≤ 0.05). RESULTS: The left mandibular 1st and 2nd premolars with one root were 47.31%, with two roots were 2.19%. However, three roots (0.24%) and C-shaped canals (0.24%) were reported only in the left mandibular 2nd premolar. The right mandibular 1st and 2nd premolars with one root were 47.56%, with two roots were 2.03%. The overall percentage of the number of roots and canals in the first and second premolars 1 PM 1 (88.38%), 2 PM 1 B 1 L 1 (3.5%), 2 PM B 1 L 1 (0.65%), 1 PM 1-2-1 (3.08%), 1 PM 1-2 (3.17%), 1 PM 1-2-1-2 (0.24%), 3 PMMB 1 DB 1 L1 (0.48%). However, the C-shaped canals (0.40%) were reported in right and left mandibular second premolars. No statistically significant difference was reported between mandibular premolars and gender. A statistically significant difference was reported between mandibular premolars and the age of the study subjects. CONCLUSION: Type I (1 TN 1) was the major root canal configuration in permanent mandibular premolars, which was higher among males. The CBCT imaging provides thorough details about the root canal morphology of lower premolars. These findings could support diagnosis, decision-making, and root canal treatment, for dental professionals.


Asunto(s)
Tomografía Computarizada de Haz Cónico Espiral , Masculino , Humanos , Diente Premolar/diagnóstico por imagen , Diente Premolar/anatomía & histología , Estudios Retrospectivos , Arabia Saudita , Cavidad Pulpar/diagnóstico por imagen , Cavidad Pulpar/anatomía & histología , Raíz del Diente/diagnóstico por imagen , Raíz del Diente/anatomía & histología , Tomografía Computarizada de Haz Cónico/métodos , Mandíbula/diagnóstico por imagen
20.
Medicina (Kaunas) ; 59(4)2023 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-37109636

RESUMEN

Background and objectives: Endodontic surgery has evolved over the last two decades. The use of state-of-the-art guided endodontic surgical procedures produces a predictable outcome in the healing of lesions of endodontic origin. The main objective of this review paper is to define and characterize guided surgical endodontics as well as its benefits and drawbacks by reviewing the most recent relevant scientific literature. Methods: A literature search was conducted using multiple databases comprising of MEDLINE (via PubMed), EMBASE, and Web of Science. The terms used for the search were 'guided endodontics', 'surgical endodontics', and 'endodontic microsurgery'. Results: In total, 1152 articles were obtained from the analysis of the databases. Unrelated articles from the available full text of 388 articles were excluded. A total of 45 studies were finally included in the review. Conclusions: Surgical-guided endodontics is a relatively new area of study that is still maturing. It has many applications such as root canal access and localization, microsurgical endodontics, endodontic retreatment, and glass fiber post removal. Additionally, it does not matter how experienced the operator is; the procedure can be completed for the patient in less time and provides greater accuracy and safety than conventional endodontics.


Asunto(s)
Endodoncia , Tratamiento del Conducto Radicular , Humanos , Tratamiento del Conducto Radicular/métodos , Endodoncia/métodos , Microcirugia/métodos
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