Assembly and Disassembly of Supramolecular Hypervalent Iodine Macrocycles via Anion Coordination.

This study explores the dynamic self-assembly and disassembly of hypervalent iodine-based macrocycles (HIMs) guided by secondary bonding interactions. The reversible disassembly and reassembly of HIMs are facilitated through anion binding via the addition of tetrabutylammonium (TBA) salts or removal of the anion by the addition of silver nitrate. The association constants for HIM monomers with TBA(Cl) and TBA(Br) are calculated and show a correlation with the strength of the iodine-anion bond. A unique tetracoordinate hypervalent iodine-based compound was identified as the disassembled monomer. Last, the study reveals the dynamic bonding nature of these macrocycles in solution, allowing for rearrangement and participation in dynamic bonding chemistry.

Production of two Nasal Sounds by Speakers with Cleft Palate.

Many speakers with cleft palate develop atypical consonant productions, especially for pressure consonants such as plosives, fricatives, and affricates. The present study investigated the nature of nasal sound errors. The participants were eight female and three male speakers with cleft palate between the ages of 6 to 20. Speakers were audio-recorded, and midsagittal tongue movement was captured with ultrasound. The speakers repeated vowel-consonant-vowel with the vowels /α/, /i/, and /u/ and the alveolar and velar nasal consonants /n/ and /η/. The productions were reviewed by three listeners. The participants showed a variety of different placement errors and insertions of plosives, as well as liquid productions. There was considerable error variability between and within speakers, often related to the different vowel contexts. Three speakers co-produced click sounds. The study demonstrated the wide variety of sound errors that some speakers with cleft palate may demonstrate for nasal sounds. Nasal sounds, ideally in different vowel contexts, should be included in articulation screenings for speakers with cleft palate, perhaps more than is currently the case.

Perceptual, durational and tongue displacement measures following articulation therapy for rhotic sound errors.

Outcomes of articulation therapy for rhotic errors are usually assessed perceptually. However, our understanding of associated changes of tongue movement is limited. This study described perceptual, durational and tongue displacement changes over 10 sessions of articulation therapy for /ɹ/ in six children. Four of the participants also received ultrasound biofeedback of their tongue shape. Speech and tongue movement were recorded pre-therapy, after 5 sessions, in the final session and at a one month follow-up. Perceptually, listeners perceived improvement and classified more productions as /ɹ/ in the final and follow-up assessments. The durations of VɹV syllables at the midway point of the therapy were longer. Cumulative tongue displacement increased in the final session. The average standard deviation was significantly higher in the middle and final assessments. The duration and tongue displacement measures illustrated how articulation therapy affected tongue movement and may be useful for outcomes research about articulation therapy.

Core-Shell Nanoparticles for Pulmonary Drug Delivery.

Nanoscale drug delivery systems have provoked interest for application in various therapies on account of their ability to elevate the intracellular concentration of drugs inside target cells, which leads to an increase in efficacy, a decrease in dose, and dose-associated adverse effects. There are several types of nanoparticles available; however, core-shell nanoparticles outperform bare nanoparticles in terms of their reduced cytotoxicity, high dispersibility and biocompatibility, and improved conjugation with drugs and biomolecules because of better surface characteristics. These nanoparticulate drug delivery systems are used for targeting a number of organs, such as the colon, brain, lung, etc. Pulmonary administration of medicines is a more appealing method as it is a noninvasive route for systemic and locally acting drugs as the pulmonary region has a wide surface area, delicate blood-alveolar barrier, and significant vascularization. A core-shell nano-particulate drug delivery system is more effective in the treatment of various pulmonary disorders. Thus, this review has discussed the potential of several types of core-shell nanoparticles in treating various diseases and synthesis methods of core-shell nanoparticles. The methods for synthesis of core-shell nanoparticles include solid phase reaction, liquid phase reaction, gas phase reaction, mechanical mixing, microwave- assisted synthesis, sono-synthesis, and non-thermal plasma technology. The basic types of core-shell nanoparticles are metallic, magnetic, polymeric, silica, upconversion, and carbon nanomaterial- based core-shell nanoparticles. With this special platform, it is possible to integrate the benefits of both core and shell materials, such as strong serum stability, effective drug loading, adjustable particle size, and immunocompatibility.

Nanostructured Lipid Carriers of Donepezil Hydrochloride for the Treatment of Alzheimer's Disease.

BACKGROUND: Alzheimer's Disease (AD) is a long-term brain disorder that worsens over time. A cholinesterase inhibitor called Donepezil HCl (DNZ) is used to treat and control AD. Due to its failure to reach the appropriate concentration in the brain cells, its efficacy upon oral administration is limited, and thus investigation of alternative administration route is necessary. OBJECTIVE: The objective of this study was to develop donepezil HCl-loaded Nanostructured Lipid Carriers (NLCs) that can bypass the blood-brain barrier and thus be directly delivered to the brain through the nasal route. This method improves availability at the site of action, reduces the negative effects of oral medication, and ensures an expedited commencement of action. METHOD: High-pressure homogenization and ultrasonication were used to formulate NLCs. Glyceryl Monostearate (GMS) as a solid lipid, Tween 80 as a surfactant, and Poloxamer 407 as a co-- surfactant were used. In this study, argan oil was employed as a liquid lipid as well as a penetration enhancer. RESULTS: The chosen NLCs displayed a particle size of 137.34 ± 0.79 nm, a PDI of 0.365 ± 0.03, and a zeta potential of -10.4 mV. The selected formulation showed an entrapment efficiency of 84.05 ± 1.30% and a drug content of 77.02 ± 0.23%. The concentration of the drug in the brain after intravenous and intranasal administration of DNZ NLCs at 1 h was found to be 0.490 ± 0.007 and 4.287 ± 0.115, respectively. Thus, the concentration of DNZ achieved in the brain after intranasal administration of DNZ NLCs was approximately 9 times more than the concentration when administered by intravenous route. CONCLUSION: The DNZ-loaded NLCs, when administered via nasal route, showed markedly improved drug availability in the brain, suggesting an efficient drug delivery strategy to treat Alzheimer's disease.

Fixed orthodontic appliances in the management of severe dental trauma in mixed dentition: a case report.

We describe a case of complex trauma to the early mixed dentition in which tooth avulsion, intrusion, extrusion and lateral luxation were managed effectively using a fixed, non-rigid orthodontic splint after treatment with a traditional wire-composite splint had failed. The use of orthodontic brackets and flexible wires provided several advantages, such as the ability to splint severely malpositioned teeth; easy assessment without removing the splint; slow, gentle repositioning of traumatized teeth; and gradual reestablishment of the arch form allowing for ease of future prosthodontic rehabilitation. Therefore, orthodontic appliances should be considered as a viable option for managing complex dental trauma.

Gingival microleakage of class V composite restorations with fiber inserts.

AIM: This study investigated the effect of different fiber inserts (glass and polyethylene), bonding agents, and resin composites on the gingival margin microleakage of class V composite restorations. MATERIALS AND METHODS: Sixty premolars were sterilized and mounted in acrylic resin bases. Class V cavities were prepared buccally and lingually, 1 mm below the cementoenamel junction, comprising 12 groups (n = 10). In the experimental groups fiber inserts were cut and placed at the gingival seat, while the control groups had no inserts. Combinations of two composite materials, Filtek-Z250 and Filtek-LS (3M-ESPE), and four bonding agents, Clearfil SE bond (Kuraray) (C), Scotch Bond Multipurpose (3M-ESPE) (SB), Prime and Bond NT (Dentsply) (PB), and Filtek-LS (3M-ESPE) (LS) were used. Restorations were incrementally inserted and polymerized for 40s. Specimens were then stored in distilled water for 7 days and thermocycled for 500 cycles. Teeth surfaces were sealed with nail polish except for 1 mm around restoration margins and immersed in 2% red procion dye. Teeth were then sectioned buccolingually and dye penetration was assessed with five-point scale. Data were statistically-analyzed by Kruskal-Wallis, ANOVA and Tukey's tests (α = 5%). RESULTS: Mean microleakage scores varied from 0.40 (Groups C, C with polyethylene, LS, LS with polyethylene) to 1.50 (SB). CONCLUSION: Different bonding agents led to differences in microleakage scores where C and LS showed significantly lower microleakage than PB. SB had highest mean microleakage score, however, incorporation of fibers resulted in significant reduction in microleakage. CLINICAL SIGNIFICANCE: Class V resin composite restorations bonded with a total-etch adhesive had a significant reduction in mean microleakage scores when glass or polyethylene fibers were placed at the gingival cavo-surface margin. In contrast, for two self-etch adhesive systems, the incorporation of fibers had no significant effect on mean microleakage scores.

An ultrasonographic investigation of cleft-type compensatory articulations of voiceless velar stops.

Ultrasound imaging was used to investigate the articulation of the voiceless velar stop [k] in five speakers with compensatory articulation related to cleft palate. The perceptual evaluation of the acoustic realization and the visual assessment of the tongue movement for the target sound were made by three examiners. The analysis revealed a variety of different compensatory strategies that included glottal stops, pharyngeal stops, midpalatal stops and glottal and velar co-productions. One patient produced palatal click sounds together with a midpalatal stop. The ultrasound imaging also revealed covert articulatory movements that would have been missed in a purely perceptual analysis. The analysis of the ultrasound images points to subphonemic aspects of cleft-type compensatory articulation that are important to understand for speech therapy.

Guiding unerupted teeth into occlusion: case report.

Delayed eruption of a permanent tooth may be a significant concern for children in the mixed dentition stage and their parents. This report describes the orthodontic management of a case in which an unerupted tooth was guided into occlusion during the mixed dentition stage, rather than waiting until the permanent dentition stage to perform comprehensive treatment. The article includes a description of the treatment mechanics for this process, which can be readily accomplished by general dentists.

A single appliance for the correction of digit-sucking, tongue-thrust, and posterior cross bite.

Clinical management of non-nutritive sucking habits and the resulting dentofacial changes often require multiple appliances to correct, leading to increased treatment time and costs. The aim of this paper was to introduce a single appliance combining a Teflon roller, a slow palatal expander, and a tongue crib appliance that is designed to correct the: (1) sucking habit; (2) anterior open bite; (3) posterior crossbite; (4) tongue thrust; and (5) molar relationships without the need for multiple treatment strategies. Moreover, the fixed-removable design ensures patient compliance, yet allows the appliance to be easily removed by the clinician for adjustments.

Vital Autotransplantation and Orthodontic Treatment of Ectopic Maxillary Canines.

The purpose of this article was to present the case of a 13-year-old patient with impacted, ectopic, permanent maxillary canines that were repositioned into their natural positions via autotransplantation without endodontic treatment and aligned into ideal occlusion via orthodontic treatment. The autotransplanted canines demonstrated normal masticatory function, physiologic mobility, and long-term tooth vitality. Clinical considerations, clinical procedures, and the rationale behind this alternative approach in managing this common growth and developmental dental anomaly are also discussed.

Antidepressant effects of ketamine and ECT: A pilot comparison.

BACKGROUND: To compare the antidepressant effects and cognitive adverse effects of intravenous ketamine infusion and Electro-convulsive therapy (ECT) in persons with severe depressive episodes. METHODS: This assessor-blinded randomized control trial included 25 patients (either sex; 18-65 years) meeting ICD-10 criteria for severe depression (bipolar or unipolar). Patients received either ECT (n = 13) or intravenous infusions of ketamine hydrochloride (0.5 mg/kg over 45 min; n = 12) for six alternate day sessions over a period of two weeks. Severity of depression was assessed at baseline and on every alternate day of intervention using the Hamilton Depression Rating Scale (HDRS) and self-reported Beck Depression Inventory (BDI). RESULTS: Baseline socio-demographic and clinical variables including HDRS (ECT: 25.15±6.58; Ketamine: 23.33±4.05, p = 0.418) and BDI (ECT: 37.07±6.58; Ketamine: 33.33±9.29; p = 0.254) were comparable. Repeated-measures analysis of variance revealed that ECT patients showed significantly greater reduction in HDRS (group*time interaction effect; F = 4.79; p<0.001) and BDI scores (group*time interaction effect; F = 3.83; p<0.01). ECT patients had higher response rate than ketamine patients [HDRS: ECT- 13/13(100%) vs ketamine- 8/12 (66.70%); p = 0.04]. This was true for remission as well [ECT- 12/13(92.30%) vs ketamine- 6/12(50%), p = 0.030; both HDRS and BDI]. Performance on Digit Symbol Substitution Test (as part of the Battery for ECT-Related Cognitive Deficits scale) significantly improved in ketamine patients (p = 0.02) while that in ECT patients worsened non significantly (p = 0.30). LIMITATIONS: Relatively small sample size; higher proportion of dropouts in the Ketamine arm. CONCLUSION: This study favoured ECT over ketamine for a better efficacy over six treatment sessions in severe depression. The results need to be replicated in larger studies. TRIAL REGISTRATION: CTRI/2019/09/021184.

Lack of oral care policies in Toronto daycares.

OBJECTIVES: Currently, there is a deficit of information on policies regarding oral hygiene practices in Toronto daycares. It is unknown if any tooth-brushing programs are in existence and if children are permitted to follow professional advice on oral hygiene. The main objectives of this investigation were to a) determine the prevalence of oral care policies in daycares and b) examine the availability of resources. METHODS: Telephone interviews were conducted with daycare supervisors using a pretested questionnaire. Summary statistics and the chi-square test were used to analyze the results. RESULTS: Two hundred forty-nine questionnaires were completed (response rate of 99.6 percent), representing 38 percent of the total daycare population (650) in Toronto. Eighty-three percent did not have a policy on oral care and 11 percent would not cede to requests from parents or medical professionals to brush teeth. However, 50 daycares indicated that their centers used to have a tooth-brushing program, and most (79 percent) were open to establishing an oral care policy. Fifteen percent reported not having proper sinks for tooth brushing. CONCLUSIONS: Many daycares do not have a policy regarding oral hygiene. A policy that encourages and provides guidance on safe tooth-brushing procedures is needed and may improve the oral health of preschool children.

Conservative Management of Fused and Geminated Permanent Anterior Teeth.

The purpose of this case report is to present an eight-year-old patient with a permanent right central incisor that was fused with a supernumerary tooth as well as a geminated permanent left central incisor, and to describe the surgical-orthodontic-restorative management of the resultant malocclusion in the developing dentition. The fused teeth were split, mesiodistal widths of both central incisors were reduced, and the incisors were orthodontically aligned into an ideal occlusion. Both maxillary central incisors maintained vitality and normal masticatory function. We also discuss the physiological basis of the treatment plan, the clinical considerations, and how problems associated with double teeth can be managed conservatively with minimally invasive treatments for an esthetically pleasing result. (J Dent Child 2019;86(3):164-8).

Early childhood caries and access to dental care among children of Portuguese-speaking immigrants in the city of Toronto.

OBJECTIVE: To determine the influence of accessibility of dental services and other factors on the development of early childhood caries (ECC) among Toronto children 48 months of age or younger with at least one Portuguese-speaking immigrant parent. METHODS: This population-based case-control study involved 52 ECC cases and 52 controls (i.e., without ECC) identified from community centres, churches and drop-in centres by a process of network sampling. Caries status (dmft/s) was assessed by clinical examination. Access to dental care and risk factors for ECC were determined through a structured interview with the Portuguese-speaking parent. RESULTS: Forty (77%) of the children with ECC but only 28 (54%) of controls had never visited a dentist. Thirty (58%) mothers of children with ECC but only 13 (25%) mothers of controls had not visited a dentist in the previous year. Bivariate analyses revealed that low family income, no family dentist, no dental insurance, breastfeeding, increased frequency of daily snacks and low parental knowledge about harmful child feeding habits were associated with ECC. Non-European-born parents and parents who had immigrated in their 20s or at an older age were 2 to 4 times more likely to have a child with ECC than European parents and those who had immigrated at a younger age. Lack of insurance, no family dentist and frequency of snacks were factors remaining in the final logistic regression model for ECC. CONCLUSIONS: The strongest predictors of ECC in this immigrant population, after adjustment for frequent snack consumption, were lack of dental care and lack of dental insurance. These findings support targeting resources to the prevention of ECC in children of new immigrants, who appear to experience barriers to accessing private dental care and who are exposed to many of the determinants of oral disease.

Detection of interproximal demineralized lesions on human teeth in vitro using frequency-domain infrared photothermal radiometry and modulated luminescence.

Frequency-domain photothermal radiometry (FD-PTR or PTR) is used to detect mechanical holes and demineralized enamel in the interproximal contact area of extracted human teeth. Thirty-four teeth are used in a series of experiments. Preliminary tests to detect mechanical holes created by dental burs and 37% phosphoric acid etching for 20 s on the interproximal contact points show distinct differences in the signal. Interproximal contact areas are demineralized by using a partially saturated acidic buffer system. Each sample pair is examined with PTR before and after micromachining or treating at sequential treatment periods spanning 6 h to 30 days. Dental bitewing radiographs showed no sign of demineralized lesion even for samples treated for 30 days. Microcomputer tomography (micro-CT), transverse microradiography (TMR), and scanning electron microscopy (SEM) analyses are performed. Although micro-CT and TMR measured mineral losses and lesion depths, only SEM surface images showed visible signs of treatment because of the minimal extent of the demineralization. However, the PTR amplitude increased by more than 300% after 80 h of treatment. Therefore, PTR is shown to have sufficient contrast for the detection of very early interproximal demineralized lesions. The technique further exhibits excellent signal reproducibility and consistent signal changes in the presence of interproximal demineralized lesions, attributes that could lead to PTR as a reliable probe to detect early interproximal demineralization lesions. Modulated luminescence is also measured simultaneously, but it shows a lower ability than PTR to detect these interproximal demineralized lesions.

Short-term cytotoxicity assessment of components of the epiphany resin-percha obturating system by indirect and direct contact millipore filter assays.

The Epiphany Resin-Percha Obturating System was assessed for cytotoxicity, compared with gutta-percha and AH-Plus sealer. Specimen disks (Resilon, gutta-percha), filled glass rings (sealers), or imbibed cellulose disks (primer, thinning resin) were placed over Millipore filters in direct or indirect contact with HeLa cell monolayer, incubated for 2 hours, and stained with tetrazolium blue. Cytotoxicity was rated by the surrounding unstained zone: none (0 mm), mild (12 mm). Data were analyzed with one-way ANOVA and post hoc pairwise t tests. Unstained zones indicating moderate cytotoxicity were significantly larger (p < 0.05) for Epiphany primer than for thinning resin and for freshly mixed AH-Plus than for Epiphany sealer. Set sealers (24 and 48 hours), gutta-percha, and Resilon elicited noncytotoxic responses. In conclusion, cytotoxicity of set Epiphany sealer and Resilon was comparable with that of set AH-Plus and gutta-percha. Cytotoxicity of freshly mixed Epiphany sealer, primer, and thinning resin did not exceed that of freshly mixed AH-Plus.

Prevalence of oral diseases in Shwachman-Diamond syndrome.

The aim of this study was to determine the prevalence and severity of oral diseases in patients with ShwachmanDiamond syndrome (SDS). Thirty-five persons with SDS were compared to 20 healthy controls. A cross-sectional survey was carried out using self-reporting questionnaires and dental radiographs collected from the subjects and their dentists. Overall, oral diseases were more prevalent among subjects with SDS when compared to controls (p < 0.001). Persons with SDS also had more caries in both primary (p < 0.03) and permanent dentitions (p < 0.01), and also had delayed dental development (p < 0.04). Oral soft tissue pathoses, such as recurrent oral ulcerations (p < 0.00) and gingival bleeding upon brushing (p < 0.00), were significantly more prevalent in subjects with SDS. Pain on eating was also more frequent amongst persons with SDS (p < 0.008) and was often associated with oral ulcerations (p < 0.002). In conclusion, based on self-completed subject and dentist questionnaires, diseases of oral hard and soft tissues were more prevalent and severe in persons with SDS when compared with healthy controls.

Vital Autotransplantation and Orthodontic Treatment of a Transmigrant Mandibular Canine.

The purpose of this study was to present the case of a 14-year-old patient with an apically closed, transmigrated permanent canine that was autotransplanted into its natural position without endodontic treatment and orthodontically aligned into ideal occlusion. The transplanted canine maintained long-term tooth vitality, physiologic mobility, and normal masticatory function. Also discussed are the clinical considerations and rationale behind this treatment, the clinical procedure, and factors for successully implementing this alternative approach in managing this relatively common developmental dental anomaly.