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In this work, we report a green, nontoxic, no-residue method for degradation of methylene blue (MB) using Cu-Cu2O films prepared with spinach leaves extract. The photocatalytic activity for two composite films with different copper concentrations, specifically 0.01 M and 0.05 M, was investigated under natural outdoor light which has an average irradiation of 3 mW/cm2. An overall degradation of 97.7% was achieved using the 0.05 M Cu-Cu2O composite, over a time duration of 180 min. We believe that the native oxidizing property of spinach extract played a major role in enhancing the photocatalytic activities of our films and gave them equitable reaction kinetics under natural daylight.

Introduction: preservation of sound primary tooth until eruption of the permanent successors is very important in development of normal occlusion and maintaining the arch form integrity. The study purpose were to determine the knowledge, attitude and practice regarding treating deep carious primary teeth among general dental practitioners and compared them with those of pediatric dentists in Saudi Arabia. Methods: A non-experimental, descriptive, cross sectional design was used. The study participants were general dental practitioners and pediatric dentists who are working as dental practitioners in Saudi Arabia. Inclusion criteria were; Enrolled in dental work in Saudi Arabia, between the ages of 26- 60 years old, had at least one-year work experience, and could read and understand English. The validated self-designed-structured questionnaire in English language was used as an instrument for data collection. Results: One hundred seventy participants were included in the study. Fifty percent were general dentists and 50% were pediatric dentists. The majority of participants were female (116 participants 68.2%). One hundred forty-nine of participants (87.6%) were Saudi. There was highly significant difference between general dental practitioners and pediatric dentists in all three aspect of the survey (knowledge, attitude, and practice). Conclusions: This study concluded that the knowledge, attitudes and practice regarding treating deep carious lesion in primary teeth by general dental practitioners were inadequate. Study findings indicated that general dental practitioners differ in their treatment recommendations from pediatric dentists.

Zinc oxide eugenol (ZOE) has traditionally been used as a root filling material in primary teeth pulpectomy. Calcium hydroxide and iodoform (Ca(OH)2/iodoform) may have advantages as a root canal filling material to evaluate treatment success of Ca(OH)2/iodoform pulpectomy in primary teeth compared with ZOE based on clinical and radiographical criteria. All human clinical studies reporting clinical and radiographical outcomes of Ca(OH)2/iodoform compared with ZOE in primary teeth pulpectomy were identified in digital bibliographic databases. Two authors independently selected studies and extracted relevant study characteristics. Success of treatment was based on an accomplishment of specific clinical and radiographical criteria. Meta‐analyses were performed to appraise study heterogeneity and aggregated statistics. Out of 5,000 articles identified in initial search, 15 articles met all inclusion criteria, while 10 were included in the meta‐analyses. At 6‐ and 12‐month follow‐up, there were no statistically significant differences in the clinical and radiographical success rates of Ca(OH)2/iodoform and ZOE. However, ZOE was shown to have statistically significant higher success rates at ≥18‐month follow‐up. On the basis of the findings of this systematic review, we recommend that Ca(OH)2/iodoform be utilized for pulpectomy in primary teeth nearing exfoliation; conversely, ZOE should be utilized when exfoliation is not expected to occur soon. Future randomized control clinical trials with a long‐term follow‐up are needed before a reliable conclusion can be drawn as to the best pulpectomy material. The success of pulpectomy in primary teeth depends on selecting the ideal root canal filling material. It is challenging to select the appropriate filling materials for primary teeth. ZOE or ZOE/iodoform combined with Ca(OH)2 appears to be the materials of choice if primary teeth are not nearing exfoliation. More high‐quality randomized control clinical trials with a long‐term follow‐up period are needed before a reliable conclusion can be drawn as to the best pulpectomy material in primary teeth (systematic review registration number: CRD42016037563).

Dental caries are most likely to occur on occlusal surfaces from the early eruptive stages of the tooth. In children, about 80% to 90% of dental caries are occlusal caries. Different preventive modalities are used to prevent occlusal caries. One of the methods used for occlusal caries prevention is fluoride varnish. A vast number of clinical trials have evaluated several types of sealant material and fluoride varnish to assess their ability to prevent occlusal caries in both primary and permanent dentition. The purpose of the current study was to provide an updated overview of the development, composition, mechanism of action, application, and safety of fluoride varnish, as well as its effect on occlusal caries prevention. This review of recently published studies on fluoride varnish and its effect on occlusal caries prevention shows that in children at moderate to high risk of caries, fluoride varnishes prevent occlusal caries. Both resin-based fissure sealants and fluoride varnish are effective for occlusal caries prevention for first-permanent molars. However, it was not possible to identify which one has the best effect. It is recommend that fluoride varnish is applied for children at high risk of caries two to four times per year.

In this work, silver nanoparticles (Ag NPs) were synthesized using a chemical reduction approach and a pulsed laser fragmentation in liquid (PLFL) technique, simultaneously. A laser wavelength of 532 nm was focused on the as produced Ag NPs, suspended in an Origanum majorana extract solution, with the aim of controlling their size. The effect of liquid medium concentration and irradiation time on the properties of the fabricated NPs was studied. While the X-ray diffraction (XRD) pattern confirmed the existence of Ag NPs, the UV–Vis spectrophotometry showed a significant absorption peak at about 420 nm, which is attributed to the characteristic surface plasmon resonance (SPR) peak of the obtained Ag NPs. By increasing the irradiation time and the Origanum majora extract concentration, the SPR peak shifted toward a shorter wavelength. This shift indicates a reduction in the NPs’ size. The effect of PLFL on size reduction was clearly revealed from the transmission electron microscopy images. The PLFL technique, depending on experimental parameters, reduced the size of the obtained Ag NPs to less than 10 nm. The mean zeta potential of the fabricated Ag NPs was found to be greater than −30 mV, signifying their stability. The Ag NPs were also found to effectively inhibit bacterial activity. The PLFL technique has proved to be a powerful method for controlling the size of NPs when it is simultaneously associated with a chemical reduction process.

Objectives. To evaluate the internal adaptation of recent pulp capping materials (TheraCal and Biodentine) relative to MTA when used as indirect pulp capping for primary teeth. Materials and Methods. Thirty primary molars were randomly allocated into three groups, group (A) was TheraCal, group (B) was Biodentine, and MTA was the control group (C). A standardized round class-V cavity (1.5 mm diameter and 2 mm depth) was prepared using a milling machine on the buccal surface of each tooth with the pulpal floor located on the dentin. Then, pulp-capping materials were applied. Finally, all teeth were restored by composite restoration. The internal adaptation of the pulp-capping materials to the dentinal surface was investigated by microcomputed tomography (Micro-CT) to determine the internal gap volume, and by optical coherence tomography (OCT) to determine the high-intensity reflection of light from the floor. Results. Based on Micro-CT findings, TheraCal showed significantly higher internal gap volume than both MTA and Biodentine ( p < 0.001 ), while MTA and Biodentine did not show a significant difference in the gap volume. Based on the OCT findings, TheraCal showed a significantly higher intensity of light reflection than both MTA and Biodentine ( p < 0.001 ); however, there was no significant difference between MTA and Biodentine. Pearson’s correlation test showed that there was a strong positive correlation between Micro-CT and OCT ( r = 0.686 , N = 30 , p < 0.001 ). Conclusions. Biodentine and MTA showed a comparable result in terms of their internal adaptation on the dentinal surface of the primary teeth, and both were better than TheraCal. There is a moderate to a strong positive correlation between Micro-CT and OCT in the measurement of internal adaptation of the tested pulp capping materials. OCT can be helpful and beneficial for the clinical setting and allow dentists to screen and evaluate restorations during follow-up.

AIM To assess the penetration and microleakage of a resin infiltrant for the prevention of noncavitated white lesion progression in the fissure system of permanent teeth and compare it to a conventional sealant. MATERIALS AND METHODS Sixty extracted permanent teeth with artificially produced noncavitated white lesions were randomly distributed according to the restorative material into group I (experimental) which received ICON resin infiltration, and group II (control) which received Helioseal F fissure sealant. For the penetration test, restorative materials were mixed with a fluorescent dye (eosin H) before light curing; roots were then amputated, and three buccopalatal microscopic sections were obtained from each tooth. These were dipped in 0.001 mg of ethanolic sodium fluorescence solution. Material penetration depth was assessed through confocal microscopy. Thirty teeth (15 from each group) underwent a microleakage test. Teeth were thermocycled, and then immersed in 50% silver nitrate (AgNO3) solution for 3 hours. Microleakage was evaluated using X-ray microtomography (micro-CT); AgNO3 presence between the material and the tooth surface indicated microleakage. RESULTS The mean material penetration value in teeth treated with ICON (104.8571 ± 7.63360 μm) was significantly higher than that in teeth treated with Helioseal F (5.3158 ± 3.83825 μm) (p < 0.001). The mean microleakage value in demineralized enamel treated with Helioseal F (0.2238 ± 0.12561) was significantly greater than that in demineralized enamel treated with ICON (0.0119 ± 0.0097) (p < 0.001). CONCLUSION ICON displayed more penetration and less microleakage than Helioseal F in pits and fissures of permanent teeth. CLINICAL SIGNIFICANCE Resin infiltrant showed superior retention and can provide a good alternative for adhesives and fissure sealants. How to cite this article: Al-Tuwirqi AA, Alshammari AM, Felemban OM, et al. Comparison of Penetration Depth and Microleakage of Resin Infiltrant and Conventional Sealant in Pits and Fissures of Permanent Teeth In Vitro. J Contemp Dent Pract 2019;20(11):1339-1344.

Background/purpose: Resin infiltration (RI) material ICON is used in treating early proximal caries lesions, as it depends on a micro–invasive infiltration technology. This in vitro study aimed to evaluate the effect of ICON resin infiltration (RI) on early proximal caries by comparing surface roughness and hardness before and after treatment with RI using atomic force microscopy (AFM), automated microhardness testing system (AMHTS), and scanning electron microscopy (SEM) in vitro. Materials and methods: Twenty seven premolars extracted for orthodontic reasons were sectioned buccolingually, creating 54 specimens. Each specimen was immersed in demineralizing solution to induce caries. Only teeth with “International Caries Detection and Assessment System” codes 1 and 2 were selected. The specimens were divided randomly into either AFM, AMHTS or SEM groups, which examined demineralized enamel before and after treatment with ICON. Results: The mean average surface roughness and root mean square roughness values of demineralized enamel treated with ICON were significantly higher than untreated lesions (P

Dentigerous cysts are developmental odontogenic jaw cysts. Dentigerous cysts require early detection and prompt treatment ranging from marsupialization to complete enucleation. Few of these cysts have been reported in children younger than 12 years of age. The purpose of this case report was to describe the case of an 11-year-old boy with a dentigerous cyst associated with unerupted right mandibular canine. The clinical, radiographic and histopathologic features are discussed. This case report also describes the diagnosis of a mandibular dentigerous cyst using cone beam computed tomography, successful use of conservative enucleation and explains the need for such a radical treatment approach.

In this work, we employed two nontoxic green chemistry methods to develop solution-processed copper oxide Cu x O thin films at low annealing temperature of 200 °C. The first aqueous precursor of Cu x O was prepared by mixing the copper powder with spinach leaves extract, whereas the other solution was formulated using the water-based polyol reduction method of Cu(II) nitrate. The as-prepared precursors were then spun on SiO 2 /P + Si substrates to form nanoscale Metal-Oxide-Semiconductor (MOS) capacitors by which some valuable information about the Cu x O semiconductor films and their interfaces with dielectric were acquired. Both fabricated MOS capacitors exhibited p-type polarity with negative flat-band voltages. However, the MOS based on spinach extract-Cu x O films showed small hysteresis of 100 mV, which could be attributed to its large grain size that sequentially leads to smooth interface and less trap density.

To assess the penetration and microleakage of a resin infiltrant for the prevention of noncavitated white lesion progression in the fissure system of permanent teeth and compare it to a conventional sealant.Sixty extracted permanent teeth with artificially produced noncavitated white lesions were randomly distributed according to the restorative material into group I (experimental) which received ICON resin infiltration, and group II (control) which received Helioseal F fissure sealant. For the penetration test, restorative materials were mixed with a fluorescent dye (eosin H) before light curing; roots were then amputated, and three buccopalatal microscopic sections were obtained from each tooth. These were dipped in 0.001 mg of ethanolic sodium fluorescence solution. Material penetration depth was assessed through confocal microscopy. Thirty teeth (15 from each group) underwent a microleakage test. Teeth were thermocycled, and then immersed in 50% silver nitrate (AgNOThe mean material penetration value in teeth treated with ICON (104.8571 ± 7.63360 μm) was significantly higher than that in teeth treated with Helioseal F (5.3158 ± 3.83825 μm) (ICON displayed more penetration and less microleakage than Helioseal F in pits and fissures of permanent teeth.Resin infiltrant showed superior retention and can provide a good alternative for adhesives and fissure sealants. How to cite this article: Al-Tuwirqi AA, Alshammari AM, Felemban OM

With the gradual reduction of fossil fuels, it is essential to find alternative renewable sources of energy. It is important to take advantage of substitutes that are less expensive and more efficient in energy production. Photovoltaic concentrators (CPVs) are effective methods through which solar energy can be maximized resulting in more conversion into electrical power. V-trough concentrators are the simplest types of low-CPV in terms of design as it is limited to the use of two plane mirrors with a flat photovoltaic (PV) plate. A consequence of concentrating more solar radiation on a PV panel is an increase in its temperature that may decrease its efficiency. In this work, the thermal profile of the PV plate in a V-trough system will be determined when this system is placed in different geographical locations in Saudi Arabia. The simulation is conducted using COMSOL Multiphysics software with a ray optics package integrated with a heat transfer routine. The 21st of June was chosen to conduct the simulation as it coincides with the summer solstice. The employment of wind as a cooling method for V-troughs was investigated in this work. It was found that with the increase in wind speed, the PV panel temperature dropped significantly below its optimum operating temperature. However, due to the mirrors’ attachment to the PV panel, the temperature distribution on the surface of the panel was nonuniform. The temperature gradient on the PV surface was reduced with the increase of wind speed but not significantly. Reducing the size of the mirrors resulted in a partial coverage of solar radiation on the PV surface which helped in reducing the temperature gradient but did not eliminate it. This work can assist in testing numerous cooling models to optimize the use of V-troughs and increase its efficiency especially in locations having high ambient temperatures.

Hybrid heterostructures based on 2D molybdenum disulfide (MoS2) and organic materials are an emerging class of nanomaterials with modulated properties and potential applications for optoelectronic devices. In this work, we demonstrated the ability to fabricate hybrid MoS2-Poly(pyrrole-co-o-toluidine) thin film photodetectors using facile solution process at low temperature. Photodetectors with [9:1] ratio of [MoS2:P(Py-co-OT)] exhibited an appropriate performance in terms of responsivity and detectivity within a broadband of wavelengths that range from 420 to 750 nm. An excellent responsivity of 43.9 A/W along with a high detectivity of 1.98 × 1012 Jones and average response time of 0.36 s were achieved at 750 nm irradiation under light intensity of 300 μW.cm−2.

Aim: To compare the prevalence of PEIR in Australian and Saudi Arabian children and to investigate the relationship of PEIR with dental development. Study design: Panoramic (PAN) radiographs of 842 Australian and 456 Saudi children were screened for PEIR. The dental ages of the children with and without PEIR were assessed from the PAN radiographs using the method of Demirjian and co-workers. Results: The subject prevalence of PEIR was not statistically significant between Australian (2%) and Saudi children (0.6%) (p>0.1). The teeth most commonly affected by PEIR were the mandibular second molars and premolars. Dental impaction was observed in 31% of teeth with PEIR compared to only 0.1% of control teeth (p

Copper (Cu) and copper oxide (CuxO) nanoparticles (NPs) were fabricated via a green method using Pulsed Laser Ablation in Liquid (PLAL) technique. The Q-switched Nd:YAG laser of wavelength 532 nm was focused on a solution containing pure copper powder mixed in spinach leaves extract. The effect of ablation time, ablation medium and laser irradiance on the propreties of the produced particles were investigated. Analytical methods were employed to characterize the produced particles such as X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). TEM images showed nearly spherical NPs with diameters from 1−12 nm depending on the laser parameters. Furthermore, the TEM images showed planes spacings related to Cu and CuxO NPs which were confirmed with the XRD analysis. The size of the produced NPs was affected by the irradiation time. The liquid medium did not have a great effect on the size of the fabricated NPs. However, using spinach extract supported the production of more CuxO NPs, in comparison to using distilled water. This investigation can provide guidance to a green synthesis technique for fabricating CuxO NPs using spinach leaves extract as an ablation medium.

This work suggests a mathematical model to simulate Stimulated Raman Scattering (SRS) with selective amplification of specific Stokes lines. This phenomena was observed experimentally when the laser excitation energy (EL) was above the dissociation energy of the Raman medium (DR), while the Stokes line showing amplification was in close proximity of an atomic emission line. The proposed numerical model suggests an influence of a stimulated emission factor in addition to the normal SRS behavior. This model was applied to the Raman medium of H2 gas, with the fourth harmonic of the Nd:YAG laser, 266 nm. At this wavelength, the energy of the laser excitation source is above the dissociation limit of H2 gas. In addition, the Stokes 3 line is in close proximity of the Balmer He line. A comparison between simulated and experimental results was undertaken which showed good agreement. This concluded that the proposed model, which took stimulated emission into consideration, was a good explanation for the high conversion efficiency of the third Stokes lines as compared to other observed Stokes lines. The model also aided in the understanding of the selective amplification process of specific Stokes lines and the factors that influenced it.

Pulsed Laser Ablation in Liquid (PLAL) is considered as a robust and simple technique to produce nanomaterials. The carbon-based nanomaterials were fabricated via the PLAL technique by irradiating a graphite target with a pulsed Nd:YAG laser of wavelength 532 nm. The graphite target was immersed in distilled water and irradiated for 10 minutes. The pulse length, repetition rate, and fluence were 6 ns, 10 Hz, and 0.4 J⁄(cm^2,) respectively. The structural and physical properties of the synthesized carbon-based nanomaterials were investigated by different analysis methods. The TEM images revealed diverse carbon nanostructure such as nanospheres with a mean diameter of 50 ± 9 nm, nanospheres agglomerated in the shape of a necklace with a mean diameter of 60 ± 11 nm, nanotubes with a mean diameter of 21 nm and average length of 140 nm. However, the dominance was graphene nanosheets in multi layers. EDX spectra confirmed the synthesis of high purity carbon nanostructures with low oxygen concentration. XRD spectrum indicated the presence of carbon nanostructures with the appearance of a broad peak at 2 = 25o near the graphite peak of (002) plane. This peak is attributed to the formation of stacked layers of graphene nanosheets that are not stacked in an orderly fashion. The XRD results also confirmed the absence of Graphene Oxide (GO), however, it was transformed to reduced Graphene Oxide (rGO). The transmission UV-Vis analysis showed a strong trough at 266 nm which is attributed to the presence of carbon nanostructures. In addition, FTIR analysis showed the vibration bonds related to carbon. The nanostructures produced were semi-stable with little agglomeration as was inferred from the results of the Zeta Potential. Finally, the DLS analysis confirmed the TEM results that the majority (73%) of the sample were graphene nanosheets with average length of 575 nm and smaller portion (27%) were carbon nanospheres with average diameter of 58 nm. In this work, the PLAL technique is proved to be a simple method for producing carbon-based nanomaterials. Moreover, the results confirm that the fluence of the laser beam is an important factor that affects the type of nanostructures that could be synthesized during laser ablation.

F8BT:MEH-PPV:CN-PPV semiconducting polymer blend nanoparticles (SPNs) were synthesized with different ratios by a miniemulsion route from three different conjugated polymers; two red/orange emitting polymers; poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) and poly(2,5-di(hexyloxy)cyanoterephthalylidene) (CN-PPV), and one green emitting polymer poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT). The resulting SPNs were spherical in shape as determined by transmission electron microscopy, and exhibited tuneable photoluminescence. These optical properties were attributed to the inter-chain interactions between F8BT and the MEH-PPV, and between MEH-PPV and CN-PPV within the same nanoparticle, with no direct interactions happening between the chains of F8BT and the chains of CN-PPV. Therefore, the presence of MEH-PPV within the polyblend SPNs facilitated an indirect F8BT:CN-PPV interaction that was not possible before.

Emission from the lowest quintet state of CO is observed in low power glow discharge. Intersystem crossing from the state to the state makes transition from the state to lower lying states possible. The term values for the three lower vibrational levels of the state are found to be , and above the ground level. The fundamental vibrational frequency of the state is found to be . Analysis of the relaxation pathways of excited CO molecules via the state is carried out and transition lines assigned.

Magnesium hydroxide (Mg(OH) 2 ) hexagonal nanodisks were synthesized via a facile microwave-assisted hydrothermal process and used, for the first time , as an efficient electron mediators for the fabrication of efficient ethanol chemical sensor. The synthesized hexagonal nanodisks were characterized in terms of their morphological and structural properties. The detailed morphological and structural investigations reveal that the synthesized Mg(OH) 2 hexagonal nanodisks are grown in high density, and possessing hexagonal crystal structure. Using as-synthesized Mg(OH) 2 hexagonal nanodisks, an efficient and robust ethanol chemical sensor has been fabricated which showed a very high and reproducible sensitivity of ∼6.89 ± 0.01 μA cm −2 mM −1 with a response time of less than 10 s, linear dynamic range from 0.1 μM to 10 mM and a correlation coefficient of R = 0.9957. The limit of detection (LOD) was estimated to be ∼73 nM. This work demonstrates that the simply synthesized Mg(OH) 2 nanostructures can effectively be used for the fabrication of efficient ethanol chemical sensors.