Glass Ionomer Cements for the Restoration of Non-Carious Cervical Lesions in the Geriatric Patient

Effect of E-glass fibers addition on compressive strength, flexural strength, hardness, and solubility of glass ionomer based cement

BACKGROUND

In dentistry, glass-ionomer cements (GICs) are extensively used for a range of applications. The unique properties of GIC include fluoride ion release and recharge, chemical bonding to the tooth's hard tissues, biocompatibility, a thermal expansion coefficient like that of enamel and dentin, and acceptable aesthetics. Their high solubility and poor mechanical qualities are among their limitations. E-glass fibers are generally utilized to reinforce the polymer matrix and are identified by their higher silica content.

OBJECTIVES

The purpose of the study was to assess the impact of adding (10 wt% and 20 wt%) silane-treated E-glass fibers to traditional GIC on its mechanical properties (compressive strength, flexural strength, and surface hardness) and solubility.

METHODS

The characterization of the E-glass fiber fillers was achieved by XRF, SEM, and PSD. The specimens were prepared by adding the E-glass fiber fillers to the traditional GIC at 10% and 20% by weight, forming two innovative groups, and compared with the unmodified GIC (control group). The physical properties (film thickness and initial setting time) were examined to confirm operability after mixing. The evaluation of the reinforced GIC was performed by assessing the compressive strength, flexural strength, hardness, and solubility (n = 10 specimens per test). A one-way ANOVA and Tukey tests were performed for statistical analysis (p ≤ 0.05).

RESULTS

The traditional GIC showed the least compressive strength, flexural strength, hardness, and highest solubility. While the GIC reinforced with 20 wt% E-glass fibers showed the highest compressive strength, flexural strength, hardness, and least solubility. Meanwhile, GIC reinforced with 10 wt% showed intermediate results (P ≤ 0.05).

CONCLUSION

Using 20 wt% E-glass fiber as a filler with the traditional GIC provides a strengthening effect and reduced solubility.

Novel electro-spun fabrication of blended polymeric nanofibrous wound closure materials loaded with catechin to improve wound healing potential and microbial inhibition for the care of diabetic wound

Diabetic wound infections caused by the multiplication of infectious pathogens and their antibiotic resistance. Wound infection evident by bacterial colonization and other factors, such as the virulence and host immune factors. In this context, we need discover appropriate treatment and effective antibiotics for wound infection control. Considering this, we synthesized catechin-loaded polyvinyl alcohol/Chitosan (PVA/CS) based nanofiber for multifunctional wound healing. The physicochemical and biological properties of fabricated nanofiber, were systematically evaluated by various spectroscopy and microscopy techniques. The CA@PVA/CS nanofiber exhibited a high level of antibacterial and antioxidant effects. The nanofibers showed effective control in gram-positive and negative wound infectious bacterial multiplication at the lowest concentration. Based on the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability study CA@PVA/CS nanofiber shows excellent biocompatibility against L929 cells. In wound, scratch assay results revealed that the CA@PVA/CS treated group shows enhanced cell migration and cell proliferation within 48 h. The synthesis of antioxidant, antibacterial, and biocompatible nanofiber exposes their potential for effective wound healing. Current research hypothesized catechin loaded PVA/CS nanofiber could be a multifunctional and low-cost material for diabetic wound care application. Fabricated nanofiber would be improved skin tissue regeneration and public health hygiene.

Do bioactive materials show greater retention rates in restoring permanent teeth than non-bioactive materials? A systematic review and network meta-analysis of randomized controlled trials

OBJECTIVES

To answer the following research question: does the clinical evaluation of restorations on permanent teeth with bioactive materials show greater retention rates than those with non-bioactive materials?

MATERIALS AND METHODS

A search strategy was used in the following databases: MEDLINE via PubMed, Scopus, Web of Science, LILACS, BBO, Embase, The Cochrane Library, and OpenGrey. Randomized controlled trials (RCTs), with a minimum of 2-year follow-up and evaluating at least one bioactive material in permanent teeth were included. Risk of bias was detected according to the Cochrane Collaboration tool for assessing the risk of bias (RoB 2.0), and network meta-analysis was performed using a random-effects Bayesian-mixed treatment comparison model.

RESULTS

Twenty-seven studies were included. The success of the restorations was assessed using modified USPHS system in 24 studies and the FDI criteria in 3 studies. Network meta-analysis revealed three networks based on restoration preparations. Resin composites were ranked with higher SUCRA values, indicating a greater likelihood of being the preferred treatment for class I, II, and III restorations. In class V, resin-modified glass ionomer cement was ranked with the highest value.

CONCLUSION

Bioactive restorative materials showed similar good clinical performance in terms of retention similarly to conventional resin composites.

CLINICAL SIGNIFICANCE

The findings must be interpreted with caution because many RCT on restorative materials aim to verify the equivalence of new materials over the gold standard material rather than their superiority. The present systematic review also suggests that new RCT with longer follow-up periods are necessary.

Dental innovations which will influence the oral health care of baby boomers

From the widespread use of smartphones and tablets to the multitude of applications available, older adults are showing an interest in utilizing technology to maintain their independence and to improve their quality of life. As technology continues to advance and be incorporated into many day-to-day activities, the baby boom generation will see these changes affecting the way they access and utilize dental services. Innovative toothbrushes and chemotherapeutics are continuing to be developed and utilized by many older adults. Within the dental office, older adults are seeing greater application of technology in every day dental procedures. These include the use of teledentistry, artificial intelligence (AI), innovative restorative materials, digitization of fixed and removable prosthodontics, cone beam computed tomography (CBCT) scans to guide dental implant placement and endodontic procedures. There is also new technology to aid in cancer detection and shielding during cancer treatment. Improved communication between the medical and dental fields has become increasingly necessary to facilitate effective patient care and a few innovative healthcare systems have begun to consolidate these services. Overall, the baby boom generation will continue to see dental innovations that will change the way they experience everyday life and dental services.

Bioactive Materials for Direct and Indirect Restorations: Concepts and Applications

Currently, minimally invasive restorations could be made in dentistry applying adhesive materials and adhesion principles to the dental structures. Following this philosophy, endodontic interventions have been avoided largely, preserving hard tissues, and maintaining dental vitality. Advances in biologically favorable bioactive materials enabled clinicans to induce repair and regeneration of dental tissues. Such materials are primarily used for pulp protection and cementation of indirect restorations. This review highlights current bioactive materials available, principles of bioactivity and their mechanisms of action.

Titanium dioxide nanotubes added to glass ionomer cements affect S. mutans viability and mechanisms of virulence

This in vitro study evaluated the impact of TiO2 nanotubes (n-TiO2) incorporated into glass ionomer cement (GIC) on Streptococcus mutans (S. mutans) characteristics at cellular and molecular levels. n-TiO2, synthesized by the alkaline method (20 nm in size), was added to Ketac Molar EasyMix® at 0%, 3%, 5%, and 7% by weight. S. mutans strains were cultured on GIC disks with addition or not of n-TiO2 for 1, 3, and 7 days and the following parameters were assessed: inhibition halo (mm) (n=3/group); cell viability (live/dead) (n=5/group); cell morphology (SEM) (n=3/group); and gene expression by real-time PCR (vicR, covR, gtfB, gtfC, and gtfD) (n=6/group). The data were analyzed by the Kruskal-Wallis test, repeated-measures ANOVA or two-way ANOVA, and Tukey's and Dunn's post-hoc tests (α=0.05). The agar diffusion test showed a higher antibacterial property for 5% n-TiO2 compared with 3% and 7% (p<0.05) with no effect of time (1, 3, and 7 days). The cell number was significantly affected by all n-TiO2 groups, while viability was mostly affected by 3% and 5% n-TiO2, which also affected cell morphology and organization. Real-time PCR demonstrated that n-TiO2 reduced the expression of covR when compared with GIC with no n-TiO2 (p<0.05), with no effect of time, except for 3% n-TiO2 on vicR expression. Within-group and between-group analyses revealed n-TiO2 did not affect mRNA levels of gtfB, gtfC, and gtfD (p>0.05). Incorporation of n-TiO2 at 3% and 5% potentially affected S. mutans viability and the expression of key genes for bacterial survival and growth, improving the anticariogenic properties of GIC.

Comparison of microleakage between different restorative materials to restore marginal gap at crown margin

Background

An occurrence of secondary caries around the indirect restoration margin is reported to remain a leading cause of failures.

Objective

This study aimed to test the interfacial microleakage of conventional glass-ionomer (CGI), resin-modified glass ionomer (RMGI) and Nano-hybrid composite (CR) restorations at a full veneer margin crown.

Methods

Ninety human extracted molar teeth were divided into three groups (n = 30). Each group was subdivided into three subgroups (n = 10) according to the extent of the structural defects; The structural defect in G1 had a depth of 1.5 mm, width and length at 2 mm and 1 mm intrusion within the crown cervical margin. The corresponding structural defect dimension values for G2 were 2, 5, 4 and 2 mm with defects extending onto the root structure. Meanwhile, G3: structural deficiency of 2 mm depth, 3 mm width and 3 mm length and with 1.5 mm extension into the prepared teeth. These structural defects in each subgroup were restored with CGI, RMGI and CR. Artificial carious lesion formation was induced at the cervical finish line with a demineralizing solution. The artificial carious lesions were restored as per the group distribution. Subsequently, teeth samples were prepared and cemented with Nickel-chromium full coverage restorations utilizing glass-ionomer luting cement. Teeth samples were thermocycled, isolated with nail varnish, and immersed in 0.1% methylene blue for 24 h. The teeth samples were sectioned longitudinally, dye penetration was evaluated with a stereomicroscope. The data were analyzed with Kruskal–Wallis and Mann–Whitney U tests.

Results

CGI-G1 recorded the highest micro-leakage score at 1.450; while CR-G3 recorded the least score (0.350). At a cementum-restoration interface, CR-G1 (0.850) documented the lowest micro-leakage; RMGI-G3 had a greater value at 1.700.

Conclusions

The hybrid CR could be effectively used to restore the restoration of a marginal gap around crown margins.

Numerical Three-dimensional Finite Element Modeling of Cavity Shape and Optimal Material Selection by Analysis of Stress Distribution on Class V Cavities of Mandibular Premolars

Aim:

Adhesive restoration does not depend primarily on the configuration of the shape of the cavity. Under varying loading conditions, it is essential to know the stress concentration and load transfer mechanism for distinct cavity shapes. The aim of this study was to evaluate and compare the biomechanical characteristics of various cavity shapes, namely oval, elliptical, trapezoidal, and rectangular shapes of class V cavities on mandibular premolars restored with amalgam, glass ionomer cement, and Cention N using three-dimensional (3D) finite element analysis.

Materials and Methods:

A 3D prototype of a mandibular premolar was generated by Digital Imaging and Communications in Medicine (DICOM) images obtained from the cone beam computed tomography and imported to 3D modeling software tool, SpaceClaim. The four distinct load magnitudes of 100, 150, 200, and 250N were applied as a pressure load perpendicular to the lingual plane of the lingual cusp of the occlusal surface (normal load) and at 45° to same (oblique load). The stress distribution patterns and the maximum von Mises stresses were analyzed and compared.

Results:

The occlusal stresses were distributed from the force loading point in an approximate actinomorphic pattern, and when the force load was close to the margin, the stress was much greater.

Conclusion:

Ovoid cavity showed lesser stress concentration and deformation for each of the tested restorative material.