Comparative Evaluation of Effectiveness of Calcium Hydroxide, MTA, and TheraCal LC in Indirect Pulp Capping in Primary Molars: In Vivo Study.

AIM: This investigation aimed to observe the effects of Dycal, mineral trioxide aggregate (MTA), and TheraCal LC, as indirect pulp-capping materials in primary molars. MATERIALS AND METHODS: About 75 children with lower primary molars aged between 4 and 7 years suggested for IPC were selected and randomly allocated into: Group I - Dycal, group II - MTA, and group III - TheraCal LC. An immediate postoperative radiograph was taken after the procedure. Recall examination was done after 3 and 6 months for clinical and radiographic assessment. The radiographs were digitized, and the amount of thickness of dentin was assessed using Corel Draw software. The values were tabulated and subjected to paired t-tests and independent t-tests for intra and intergroup analysis, respectively. The p-value < 0.05 was considered statistically significant. RESULTS: There was a statistically significant increase in dentin thickness in the first 3 months compared to the 6-month follow-up. At the end of the research phase, TheraCal LC had more tertiary dentin deposited than MTA, followed by Dycal. CONCLUSION: TheraCal LC can be a reliable indirect pulp-capping agent in primary teeth. CLINICAL SIGNIFICANCE: Indirect pulp capping (IPC) is a very extensively employed treatment regimen to manage extensive caries. For many decades, calcium hydroxide has been regarded as the benchmark of pulp capping materials. With several advancements in materials for restoration, TheraCal LC a resin-modified, light-cured calcium silicate-filled liner serves as a pulp-capping agent and dentin protector, promoting pulp healing and preserving vitality as an obstacle cum protector of the dental pulp complex. How to cite this article: Thomas NA, Jobe J, Thimmaiah C, et al. Comparative Evaluation of Effectiveness of Calcium Hydroxide, MTA, and TheraCal LC in Indirect Pulp Capping in Primary Molars: In Vivo Study. J Contemp Dent Pract 2024;25(4):365-371.

Apparent amylose content positively influences the quality of extruded fortified rice kernels.

The present research studies the impact of apparent amylose content (AAC) on the quality of fortified rice kernels (FRK), a health food designed to combat iron deficiency anemia by fortifying with iron, folic acid, and vitamin B12. Five FRK formulations with varying AAC (0.46-23.89 %) were prepared, and AAC influence on the extruder-system parameter and physicochemical, cooking, and textural properties of FRK was investigated. The torque, die-pressure, length, redness, and cooking time increased with an increase in AAC and were in the range of 12.55-22.81 Nm, 58.31-88.96 bar, 4.58-5.09 mm, 0.35-1.15, and 6.1-11.2 min, respectively. The other parameters, such as the breadth, whiteness index, and cooking loss decreased with an increase in AAC. Except for cohesiveness, all other textural properties of cooked FRK increased with an increase in AAC. These correlations of the FRK properties with AAC were confirmed through multivariate analysis. SEM, XRD, FTIR, and rheology supported the observed AAC trends in FRK properties. SEM showed a reduction in pores and cracks with an increase in AAC. The XRD and FTIR showed an increase in crystallinity with an increase in AAC due to better gelatinization leading to rapid retrogradation. This leads to better physical, cooking, and textural properties of FRK.

Effect of Bonding Agents on the Shear Bond Strength of Tooth-colored Restorative Materials to Dentin: An In Vitro Study.

AIM: The aim of the study is to determine the difference in the shear bond strengths to dentin among dental composite (Filtek Z350®, 3M), compomer (Dyract Flow®, Dentsply) and Giomer (Beautifil®, Shofu) with 3MTM Single BondTM Universal Adhesive (SBU) (7th generation, self-etch, single solution adhesive) and AdperTM Single Bond 2 Adhesive (ASB) (5th generation, total-etch, two solution adhesive). MATERIALS AND METHODS: Sixty extracted human permanent teeth were collected, cleansed of debris, and placed in distilled water. The samples were segregated into two groups depicting the two bonding agents-AdperTM (ASB) and 3MTM Single Bond Universal (SBU) and sub-grouped into three groups depicting the three restorative materials (Composite, Giomer, and Compomer) used. Groups were respresented as follows: Group I-ASB + Composite; Group II-ASB + Giomer; Group III-ASB + Compomer; Group IV-SBU + Giomer; Group V-SBU + Compomer; Group VI-SBU + Composite. After applying the bonding agent as per the manufacturer's instructions, following which the restorative material was placed. A Universal Testing Machine (Instron 3366, UK) was employed to estimate the shear bond strength of the individual restorative material and shear bond strengths were calculated. RESULTS: Composite bonded with SBU (group VI) displayed the greatest shear strength (11.16 ± 4.22 MPa). Moreover, Giomers and flowable compomers displayed better bond strengths with ASB compared with their SBU-bonded counterparts. CONCLUSION: These results mark the importance of careful material selection in clinical practice and the bonding agent used to achieve optimal bond strength and enhance the clinical longevity and durability of dental restorations. CLINICAL SIGNIFICANCE: From a clinical perspective, to avoid a compressive or a shear failure, it would be preferrable to use a direct composite restorative material with SBU (Single bond universal adhesive, 7th generation) to achieve maximum bond strength. How to cite this article: Kuchibhotla N, Sathyamoorthy H, Balakrishnan S, et al. Effect of Bonding Agents on the Shear Bond Strength of Tooth-colored Restorative Materials to Dentin: An In Vitro Study. J Contemp Dent Pract 2024;25(3):245-249.

Effect of microwave drying and tempering on color attributes, fissure formation, and cooking characteristics of fortified rice kernels.

Fortified rice kernels (FRK) are a vitamin-mineral enriched extruded rice-shaped product blended with raw or parboiled rice in a 1:100 ratio to prepare fortified rice. In FRK manufacturing, drying is one of the essential steps that affect the quality of FRK. In the present study, the microwave technique was explored to dry FRK continuously at 180, 360, and 540 W and with the tempering (1, 2, and 3 min) at 180 W to evaluate the effects on the drying curves, color attributes, fissure formation, and cooking characteristics. Thin layer modeling suggested the Two-term exponential model (two parameters), diffusion model (three parameters), and Midilli Kucuk (four parameters) as the best models to predict moisture based on Akaike and Bayesian information criteria. The higher MWP (360 and 540 W) significantly lowered the L* and WI while increasing the a*, b*, and BI compared to 180 W, which was undesirable. Image processing showed fissures in all FRK samples; however, 1 min and 2 min tempering could somewhat restrict the fissure. The fissures caused higher solid losses and increased splitting of kernels during cooking. It can be concluded that the low MWP (< 180W) with appropriate tempering time can be used to dry FRK. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-023-05871-4.

The effect of substance P and its common in vivo-formed metabolites on MRGPRX2 and human mast cell activation.

The tachykinin neuropeptide substance P (SP) is the canonical agonist peptide for the neurokinin 1 receptor (NK1 R). More recently, it has also been shown to activate the Mas-related G protein-coupled receptor X2 (MRGPRX2) receptor on mast cells (MCs), triggering degranulation and release of inflammatory mediators. SP undergoes rapid C-terminal truncation in vivo by a number of proteases to generate the metabolites SP(1-9)-COOH and in particular SP(1-7)-COOH. While the C terminus of SP is critical for NK1 R activation, studies have shown that the peptide polycationic N terminus is key for MRGPRX2 and mast cell activation. The study thus aimed to determine if the C-terminally truncated metabolites of SP, SP(1-9)-COOH, and SP(1-7)-COOH retained stimulatory activity at MRGPRX2. SP, SP(1-9)-COOH, and SP(1-7)-COOH were synthesized and tested on HEK293 cells expressing NK1 R or MRGPRX2, and LAD2 human mast cells, to determine the activity of SP and its metabolites in Ca2+ mobilization, degranulation, and cytokine assays. As expected from prior studies, both C-terminally truncated SP metabolites had essentially no activity at NK1 R, even at very high concentrations. In contrast, the in vivo metabolite of SP, SP(1-9)-COOH retained ability to activate MRGPRX2 across all parameters tested, albeit with reduced potency compared to intact SP. SP(1-7)-COOH did not produce any significant MRGRPX2 activation. Our results suggest that the SP metabolite, SP(1-9)-COOH, may play a regulatory role through the activation of MRGPRX2. However, given the relatively low potency of both SP and SP(1-9)-COOH at MRGPRX2, additional work is needed to better understand the biological importance of this expanded SP/MRGPRX2 pathway.

Antibody or Anybody? Considering the Role of MRGPRX2 in Acute Drug-Induced Anaphylaxis and as a Therapeutic Target.

Acute anaphylaxis to small molecule drugs is largely considered to be antibody-mediated with immunogloblin E (IgE) and mast cell activation being key. More recently, a role for drug-reactive immunoglobulin G (IgG) with neutrophil activation has also been suggested, at least in reactions to neuromuscular blocking agents (NMBAs). However, the mast cell receptor MRGPRX2 has also been highlighted as a possible triggering mechanism in acute anaphylaxis to many clinically used drugs. Significantly, MRGPRX2 activation is not dependent upon the presence of drug-recognising antibody. Given the reasonable assumption that MRGPRX2 is expressed in all individuals, the corollary of this is that in theory, anybody could respond detrimentally to triggering drugs (recently suggested to be around 20% of a drug-like compound library). But this clearly is not the case, as the incidence of acute drug-induced anaphylaxis is very low. In this mini-review we consider antibody-dependent and -independent mechanisms of mast cell activation by small molecule drugs with a focus on the MRGPRX2 pathway. Moreover, as a juxtaposition to these adverse drug actions, we consider how increased understanding of the role of MRGPRX2 in anaphylaxis is important for future drug development and can complement exploration of this receptor as a drug target in broader clinical settings.

MRGPRX2 activation in mast cells by neuromuscular blocking agents and other agonists: Modulation by sugammadex.

BACKGROUND: Neuromuscular-blocking agents (NMBAs) can cause both IgE-dependent and IgE-independent anaphylactic reactions, with activation of the mast cell receptor MRGPRX2 being important to the latter. Sugammadex, a reversal agent for certain aminosteroid NMBAs, has been proposed as an antidote for these anaphylactic events with conflicting outcomes. OBJECTIVE: We further characterize the involvement of MRGPRX2 in NMBA-induced mast cell activation and determine how this is influenced by sugammadex. We then apply these in vitro results to infer the possible utility of sugammadex in the acute management of non-IgE-dependent anaphylaxis. METHODS: The LAD2 human mast cell line and a MRGPRX2 knock-down derivative were used to validate the involvement of MRGPRX2 and to test the effect of sugammadex on mast cell activation by NMBAs and other MRGPRX2 agonists. RESULTS: All MRGPRX2 agonists tested were shown to induce MRGPRX2-dependent LAD2 mast cell calcium mobilization and cytokine release and all, apart from rocuronium, induced degranulation. Co-treatment of mast cells with sugammadex and some MRGPRX2 agonists significantly reduced cell activation, but if sugammadex was administered a few minutes following stimulation, degranulation was not attenuated. However, addition of sugammadex up to 180 min following LAD2 MRGPRX2 stimulation, significantly reduced CCL2 mRNA and protein induction. CONCLUSIONS AND CLINICAL RELEVANCE: We show that sugammadex, known to reverse muscle blockade by certain NMBAs, is also able to reduce MRGPRX2 activation by NMBAs and other, but not all, MRGPRX2 agonists. As sugammadex was ineffective in attenuating mast cell degranulation when added rapidly post MRGPRX2 activation, this suggests against the agent having efficacy in controlling acute symptoms of anaphylaxis to NMBAs caused by MRGPRX2 activation. Interestingly, however, sugammadex did impair MRGPRX2-induced CCL2 release, suggesting that it may have some benefit in perhaps dampening less well-defined adverse effects of MRGPRX2-dependent anaphylaxis associated with the more slowly elaborated mast cell mediators.

Photocatalytic and antimicrobial activities of chitosan-TiO2 nanocomposite.

Chitosan, a natural polysaccharide widely used for various biological applications due to their potential benefits. Incorporation of biomaterials with semiconductor has been exploited for waste water treatment and biological applications due to their nanometric sizes and biocompatibility of chitosan. Chitosan-Titanium dioxide (CS-TiO2) nanocomposite was synthesized and their optical, structural, spectral, thermal, morphological and elemental analyses were carried out by several techniques. The particle size of the synthesized CS-TiO2 nanocomposite was around 90nm and has a crystalline structure with anatase phase of TiO2. The prepared nanocomposite acts as a photocatalyst for the removal of rhodamine B (RhB) and congo red (CR) dyes under visible light irradiation. The pseudo first order kinetics was derived according to Langmuir-Hinshelwood (L-H) model. The nanocomposite also proved to be an excellent antimicrobial agent against Gram-positive and Gram-negative bacteria; and also show activity against fungus. The antimicrobial activity of the CS-TiO2 nanocomposites exhibits a zone of inhibition ranged between 10.333±0.5773 and 25.667±1.5275 (mm).

Pediatric brain tumors: An analysis of 5 years of data from a tertiary cancer care center, India.

BACKGROUND: Pediatric brain tumors are the most common solid tumors in children and a leading cause of mortality and morbidity in children worldwide. Even though there are enough data about the epidemiology of pediatric brain tumors in western population, there are only a few reports from developing countries like India. AIMS: To study the epidemiological patterns of brain tumors in children, to study the patterns of care, and to assess the treatment response. MATERIALS AND METHODS: A retrospective epidemiological approach is used. The records of children <18 years registered in our department from August 2006 to July 2011 diagnosed as primary brain tumors are selected. Data regarding age, sex, site of the tumor, clinical features, histology, treatment plan, and treatment response are collected. The World Health Organization classification of neoplasms was adopted. RESULTS: Of 250 cases, females (57%) slightly outnumbered males. The present study revealed that astrocytoma (52%) is the most common brain tumor in childhood. Surgery was the main modality of treatment. Chemotherapy was given to 16% of patients. Even though radiation therapy was offered to 74% of patients, only 42% completed radiotherapy. There was subjective clinical improvement in 68% of patient population after treatment. CONCLUSIONS: This is the second study from Tamil Nadu that deals with epidemiology of brain tumors. Multimodality management including surgery, chemotherapy, and radiation therapy remains the cornerstone in the management of pediatric brain tumors.