An overview of dentin bonding agents

From the past, there has been a lot of use of the bonding agents in restorative dentistry. Choosing of bonding systems has become a challenge for the clinicians as there was a lot of advances regarding the usage of bonding agents. Each successive modification in the formulae has led to the classification of the bonding system into many “generations”. During the past few years, these bonding agents have been replaced by the same systems that are used on dentin. This change occurred because of the benefit of bonding resin to both enamel and dentin. Extensive research is still on the way to develop the best adhesive system that can produce reliable and permanent bonds to dentin

Self-sealing resin fixators in dentistry

Fixed indirect restorations bond to the prepared tooth surfaces with the use of a variety of luting agents depending upon the purpose of that rehabilitation. Success and failures of these restorations have been attributed to the quality of their bond with the tooth substrate. However, the advent of resin-based and self-adhesive resin luting agents have greatly changed this equation by altering the conventional bonding mechanisms and the durability of bond. The limited literature details of these self-adhesive resin luting agents require further exploration for the benefit of dental professionals. This review provides an overview of the composition, chemical interactions, favourable and unfavourable properties to be known for improving the scope of their utilization in dentistry

Solubility of glass ionomer cement in various acidic beverages at different time intervals: an in vitro study

Background: Glass Ionomer is a widely used cement in dentistry for luting and restoration purposes. This cement leaches a large amount of fluoride ions leading to an increase in the early solubility and disintegration in the oral fluids. The solubility of the cement is further aggravated when it is exposed to an acidic medium. Aim: This study aimed to evaluate the solubility of glass ionomer cement (GIC) in various acidic beverages at different time intervals. Materials and Methods: Four commercially available beverages and distilled water was used as immersion media. The pH of the beverages was measured using a digital pH meter. Glass ionomer cement discs were prepared and immersed in beverages for 1 day, 24 hours and 7 days. After completing the immersion time in each beverage for a specific period, the specimens were retrieved and weighed. The solubility was calculated by subtracting the weight at the specific immersion period from the initial weight of the specimen.   Results: Immersion in distilled water demonstrated less solubility compared to immersion in acidic beverages. Among the acidic beverages, GIC immersed in MAAZA showed the maximum solubility compared to the other beverages. One-Way ANOVA displayed a significant difference (p=0.000) among the beverages at different time intervals. Conclusions: This study found that the GIC immersed in fruit juices with preservatives showed more solubility at all time intervals compared to the immersion in carbonated drinks

Mineral Trioxide Aggregate: an overview of composition, properties and clinical applications

“Mineral trioxide aggregate” is a cementitious material, which is popular by its trade name MTA. It was first introduced in the year 1993 by Mohmoud Torabinejad at Loma Linda University in California, USA. MTA is a powder mixture of Portland cement clinker, bismuth oxide, and gypsum. It has gained a lot of importance in dentistry in recent years. This importance is because of its extensive use as apical restorative material as well as a medicament for Apexogenesis and Apexification treatment. As it sets by hydration process, the byproducts of insoluble calcium silicate hydrate and alkaline calcium hydroxide offer unique stability and potential to enhance hard tissue regeneration.  This article reviewed the composition, types, properties of MTA and also its applications in the practice of dentistry

BKM Lie superalgebra for the Z_5 orbifolded CHL string

We study the Z_5-orbifolding of the CHL string theory by explicitly constructing the modular form tilde{Phi}_2 generating the degeneracies of the 1/4-BPS states in the theory. Since the additive seed for the sum form is a weak Jacobi form in this case, a mismatch is found between the modular forms generated from the additive lift and the product form derived from threshold corrections. We also construct the BKM Lie superalgebra, tilde{G}_5, corresponding to the modular form tilde{Delta}_1 (Z) = tilde{Phi}_2 (Z)^{1/2} which happens to be a hyperbolic algebra. This is the first occurrence of a hyperbolic BKM Lie superalgebra. We also study the walls of marginal stability of this theory in detail, and extend the arithmetic structure found by Cheng and Dabholkar for the N=1,2,3 orbifoldings to the N=4,5 and 6 models, all of which have an infinite number of walls in the fundamental domain. We find that analogous to the Stern-Brocot tree, which generated the intercepts of the walls on the real line, the intercepts for the N >3 cases are generated by linear recurrence relations. Using the correspondence between the walls of marginal stability and the walls of the Weyl chamber of the corresponding BKM Lie superalgebra, we propose the Cartan matrices for the BKM Lie superalgebras corresponding to the N=5 and 6 models.Comment: 30 pages, 2 figure

An overview of composition, properties, and applications of Biodentine

A series of events leads to loss of tooth structure by dental caries, tooth wear and trauma, which is often replaced by inert dental materials that replace the bulk of the tooth. If pulp health is affected, a series of interventions need to be undertaken. Initially, the pulp vitality needs to be maintained. Later, elimination of infection and filling of the pulp space is necessary. When pulpal involvement occurs the choice of material has to change, and materials that interact with the pulp are indicated. Interactive materials used for dental procedures include calcium hydroxide in its various presentations and hydraulic calcium silicate cement.  Biodentine is a promising dentine substitute that has been recently introduced in dentistry. Although many other materials like Glass Ionomer Cement (GIC), composite and Mineral Trioxide Aggregate (MTA) are available for repair of dentin loss in tooth structure, none of them possesses ideal properties. Despite many advantages, MTA has been replaced by Biodentine, which is a new calcium silicate-based material, due to its limitations. It has good handling properties, short setting time, and improved mechanical properties. Biodentine was designed explicitly as a "dentine replacement," with applications ranging from endodontic repair to pulp capping

Evaluation of physico-mechanical properties of dental plaster modified with pulverized acrylic waste

Background: Dental plaster is most widely used to make temporary casts and as an investment medium during the fabrication of removable complete and partial denture prostheses. Dental plasters exhibit poor mechanical properties. Aim: This study aimed to evaluate the physico-mechanical properties of dental plaster modified with various concentrations of pulverized acrylic waste. Materials and Methods: A total of 120 specimens were fabricated using dental plaster and were divided into four groups of 30 specimens each to evaluate setting time, one-hour compressive strength, 24-hour compressive strength, and surface reproducibility. Each group was subdivided into five groups of six specimens (n=6), each with the incorporation of various concentrations of pulverized acrylic powder. The specimens incorporated with various concentrations of pulverized acrylic powder (0.5 wt%, 1.0 wt%, 5.0 wt% and 10.0 wt%) were considered as modified groups and the dental plaster with no additives was considered as a control group. The initial and final setting times were measured using a Gillmore needle apparatus, the compressive strength was measured using a universal testing machine, and the surface reproducibility was analyzed using a stereo microscope. The obtained data were subjected to statistical analysis using one-way ANOVA and post hoc analysis.   Results: The incorporation of 0.5 wt% resulted in more final and initial setting times. The one-hour and 24-hour compressive strengths of the dental plaster increased with increasing concentration of acrylic waste. Poor surface details were observed with an increase in the concentration of acrylic waste. Conclusions: The addition of acrylic waste resulted in an increase in the one-hour and 24-hour compressive strengths, decreased initial and final setting times, and poor surface reproducibility

Size at birth and cognitive ability in late life: A systematic review

Recent evidence suggests that growth restriction in utero may lead to neurocognitive disorders in late life, either through impaired brain development or adverse metabolic programming

Spontaneous mode non-invasive ventilation fails to treat respiratory failure in a patient with Multi-mincore disease: a case report

The increased morbidity and mortality resulting from respiratory failure in patients with neuromuscular disorders and/or kyphoscoliosis can be reversed with non-invasive ventilation. Spontaneous mode bilevel pressure ventilation is preferred to other modes of ventilation, due to relative ease of use, but may not be suitable for all patients. We report a 27-year old woman with Multi-minicore disease whose respiratory failure was refractory to spontaneous mode bilevel pressure ventilation. When we altered settings and provided mandatory inspiratory rise time and respiratory rate, it augmented her respiratory efforts and improved ventilation. Our case report describes the benefit of individualising non-invasive ventilation in the management of respiratory failure due to neuromuscular weakness and kyphoscoliosis

An overview of advances in glass ionomer cements

Glass-ionomer dental cements (GICs) are aesthetic direct restorative materials with anticariogenic activity. Glass-ionomers are composed of alumino-silicate glass powder and poly acrylic acid liquid. The significant characteristics of GICs among restorative materials are their ability to bond to moist tooth structure without any pre-treatment and to provide a prolonged period of fluoride release, which prevents subsequent tooth decay (caries). These characteristics, along with the materials\u27 acceptable aesthetics and biocompatibility, make them popular and desirable for use in medical and dental applications. However, GICs exhibit poor mechanical qualities and moisture sensitivity. To improve their mechanical and physical qualities, the GIC powders have undergone extensive formulation and modification. This paper provides an overview of various fillers used to enhance the mechanical and physical properties of GICs