Effect of Immediate Dentin Sealing on the Bonding Performance of Indirect Restorations: A Systematic Review.

The popular immediate dentin sealing (IDS) technique is used to improve the bond strength of indirect restorations. This systematic review assessed whether bond strength is affected by the type of aging conditions, bonding agents, flowable resin composites, impression materials, temporary materials, and/or resin cement used within the IDS procedure. A comprehensive database search of PubMed, Embase, Scopus, Ovid Medline, Web of Sciences, Cochrane Library, Dentistry & Oral Sciences Source, and ProQuest was carried out up to 30 January 2024 without publication year or language limitations. Only in vitro full-texts regarding the effect of IDS on bond strength were included, and the quality of their methods was assessed via a Risk of Bias (RoB) test. In total, 1023 pertinent studies were initially found, and 60 articles were selected for review after screening for the title, abstract, and full texts. IDS application improves the bond strength of indirect restorations to dentin and reduces the negative effects of temporary materials on the bond durability of final indirect restorations. Filled dentin bonding agents or combinations with flowable resin composite are preferred to protect the IDS layer from conditioning procedures.

Antibacterial and Physical Properties of PVM/MA Copolymer- Incorporated Polymethyl Methacrylate as a Novel Antimicrobial Acrylic Resin Material.

Polymethyl methacrylate (PMMA), an acrylic resin used in orthodontic appliances and removable dentures for its biocompatibility and esthetics, may harbor bacteria on its surface. The present study investigated a new PMMA formula with Gantrez: an antibacterial copolymer of methyl vinyl ether and maleic acid (PVM/MA). Samples were tested for mechanical properties (surface hardness, flexural strength, water sorption, and water solubility) and effects against Streptococcus mutans. Six groups (0%-control, 5%, 10%, 15%, 20%, and 25% Gantrez) of n = 12 were fabricated for physical property tests and analyzed with one-way ANOVA and Prism 6. From these results, three groups (0%, 5%, and 10% Gantrez) were selected for antibacterial tests, and data were analyzed with one-way ANOVA and Tukey's multiple comparison test. Adding 5% and 10% Gantrez into PMMA significantly decreased S. mutans adhesion. There was no significant difference between the control vs. 5%, 10%, 15%, and 20% Gantrez (p > 0.05) for surface hardness, the control vs. 5% Gantrez (p > 0.05) for flexural strength, and the control vs. 5 and 10% Gantrez for water sorption and water solubility. Overall, incorporating 5% Gantrez into PMMA may be a promising solution to reduce bacterial adhesion without changing the acrylic resin's physical properties.

The effect of zeolite incorporation on the physical properties of silver-reinforced glass ionomer cement.

Zeolite can impart antibacterial properties to dental materials in the long-term when incorporated with inorganic cations. However, due to its porosity, it may jeopardize the mechanical integrity of the dental material. The aim of this project was to determine the effect on physical properties when zeolite is added to commercially available Ag-reinforced Glass Ionomer Cement (GIC). Sample groups were prepared according to the percentage of zeolite-clinoptilolite (0% - control, 0.5%, 1%, 2%, and 4% wt) added to Ag-GIC. Water sorption, solubility, Vickers hardness, and flexural strength were determined. Specifically, 10 × 2 mm circular disks were fabricated for the Vickers hardness, water sorption, and water solubility tests and 25 × 5 × 2 mm bars were created for the flexural strength test. The results from the surface hardness, water sorption, and flexural strength tests suggested that adding 0.5-4% wt of zeolite to Ag-reinforced GIC did not diminish its physical properties. However, the water solubility results showed that higher concentrations (2-4% wt) of zeolite had a statistically significant increase in water solubility compared to the control. Up to 4% wt zeolite can be incorporated into Ag-reinforced GIC without compromising mechanical properties. Incorporation of 0.5-1% wt zeolite to Ag-reinforced GIC will maintain an adequate surface hardness, water sorption, and flexural strength without compromising water solubility. Further research is needed to determine the effects of higher water solubility on clinical efficacy of zeolite modified Ag-GIC. Graphical abstract.

Young children with suicidal thoughts and behaviors more likely to resolve conflicts with violence, homicide, or suicide: A study of internal working models using narratives.

There is mounting evidence that young children who express suicidal ideation (SI) have a different conceptualization of death than their peers. This study characterizes 3- to 6-year-olds' depictions of violence, death, and suicidal themes in a story completion task as a function of their history of SI. Participants were 228 children with depression (3.0-6.9 years) who completed a comprehensive psychiatric assessment and four story stem narratives. For each narrative, an interviewer began a story with a conflict that the child was encouraged to resolve. Children's resolutions were coded for standard themes and negative atypical themes including violence and homicide, accidental harm or death, and suicidal ideation/acts. Themes were examined as a function of children's SI status: active-SI (n = 25), passive-SI (n = 28), or no history of SI (n = 175). Across the narratives, 89 children described at least one negative atypical theme: violence or homicide (n = 78), accidental harm or death (n = 22), and suicide (n = 13). The responses of children with active-SI included significantly more violence or homicide than children without SI. Moreover, current active-SI predicted suicidal themes. There were no group differences in accidental harm or death, nor in common aggressive or punitive acts (e.g., hitting, yelling, spanking), indicating specificity between active-SI and more intense violence and death-related themes. In sum, young children with active SI are more likely than their depressed peers without SI to incorporate violence, homicide, and suicide into their narratives around conflict resolution. These themes appear more salient to depressed children with SI and pervasive in their thoughts and problem-solving strategies. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Effects of Zeolite as a Drug Delivery System on Cancer Therapy: A Systematic Review.

Zeolites and zeolitic imidazolate frameworks (ZIFs) are widely studied as drug carrying nanoplatforms to enhance the specificity and efficacy of traditional anticancer drugs. At present, there is no other systematic review that assesses the potency of zeolites/ZIFs as anticancer drug carriers. Due to the porous nature and inherent pH-sensitive properties of zeolites/ZIFs, the compounds can entrap and selectively release anticancer drugs into the acidic tumor microenvironment. Therefore, it is valuable to provide a comprehensive overview of available evidence on the topic to identify the benefits of the compound as well as potential gaps in knowledge. The purpose of this study was to evaluate the potential therapeutic applications of zeolites/ZIFs as drug delivery systems delivering doxorubicin (DOX), 5-fluorouracil (5-FU), curcumin, cisplatin, and miR-34a. Following PRISMA guidelines, an exhaustive search of PubMed, Scopus, Embase, and Web of Science was conducted. No language or time limitations were used up to 25th August 2021. Only full text articles were selected that pertained to the usage of zeolites/ZIFs in delivering anticancer drugs. Initially, 1279 studies were identified, of which 572 duplicate records were excluded. After screening for the title, abstract, and full texts, 53 articles remained and were included in the qualitative synthesis. An Inter-Rater Reliability (IRR) test, which included a percent user agreement and reliability percent, was conducted for the 53 articles. The included studies suggest that anticancer drug-incorporated zeolites/ZIFs can be used as alternative treatment options to enhance the efficacy of cancer treatment by mitigating the drawbacks of drugs under conventional treatment.

Antimicrobial and Mechanical Effects of Zeolite Use in Dental Materials: A Systematic Review.

OBJECTIVE: Ion-incorporated zeolite is a widely used antimicrobial material studied for various dental applications. At present, there is no other systematic review that evaluates the effectiveness of zeolite in all dental materials. The purpose of this study was to review all available literature that analyzed the antimicrobial effects and/or mechanical properties of zeolite as a restorative material in dentistry. MATERIAL AND METHODS: Following PRISMA guidelines, an exhaustive search of PubMed, Ovid Medline, Scopus, Embase, and the Dentistry & Oral Sciences Source was conducted. No language or time restrictions were used and the study was conducted from June 1, 2020 to August 17, 2020. Only full text articles were selected that pertained to the usage of zeolite in dental materials including composite resin, bonding agents, cements, restorative root material, cavity base material, prosthesis, implants, and endodontics. RESULTS: At the beginning of the study, 1534 studies were identified, of which 687 duplicate records were excluded. After screening for the title, abstract, and full texts, 35 articles remained and were included in the qualitative synthesis. An Inter-Rater Reliability (IRR) test, which included a percent user agreement and reliability percent, was conducted for each of the 35 articles chosen. CONCLUSION: Although ion-incorporated zeolite may enhance the antimicrobial properties of dental materials, the mechanical properties of some materials, such as MTA and acrylic resin, may be compromised. Therefore, since the decrease in mechanical properties depends on zeolite concentration in the restorative material, it is generally recommended to add 0.2-2% zeolite by weight.

Low-frequency blood pressure oscillations and inotrope treatment failure in premature infants.

The underlying mechanism as to why some hypotensive preterm infants do not respond to inotropic medications remains unclear. For these infants, we hypothesize that impaired vasomotor function is a significant factor and is manifested through a decrease in low-frequency blood pressure variability across regulatory components of vascular tone. Infants born ≤28 wk estimated gestational age underwent prospective recording of mean arterial blood pressure for 72 h after birth. After error correction, root-mean-square spectral power was calculated for each valid 10-min data frame across each of four frequency bands (B1, 0.005-0.0095 Hz; B2, 0.0095-0.02 Hz; B3, 0.02-0.06 Hz; and B4, 0.06-0.16) corresponding to different components of vasomotion control. Forty infants (twenty-nine normotensive control and eleven inotrope-exposed) were included with a mean ± SD estimated gestational age of 25.2 ± 1.6 wk and birth weight 790 ± 211 g. 9.7/11.8 Million (82%) data points were error-free and used for analysis. Spectral power across all frequency bands increased with time, although the magnitude was 20% less in the inotrope-exposed infants. A statistically significant increase in spectral power in response to inotrope initiation was noted across all frequency bands. Infants with robust blood pressure response to inotropes had a greater increase compared with those who had limited or no blood pressure response. In this study, hypotensive infants who require inotropes have decreased low-frequency variability at baseline compared with normotensive infants, which increases after inotrope initiation. Low-frequency spectral power does not change for those with inotrope treatment failure, suggesting dysfunctional regulation of vascular tone as a potential mechanism of treatment failure.NEW & NOTEWORTHY In this study, we examine patterns of low-frequency oscillations in blood pressure variability across regulatory components of vascular tone in normotensive and hypotensive infants exposed to inotropic medications. We found that hypotensive infants who require inotropes have decreased low-frequency variability at baseline, which increases after inotrope initiation. Low-frequency spectral power does not change for those with inotrope treatment failure, suggesting dysfunctional regulation of vascular tone as a potential mechanism of treatment failure.