Effects of eye dominance on shade matching and color perception among the dentist population

Objectives

The purpose of this study was to evaluate the influence of eye dominance on color perception, and shade matching.

Materials and Methods

A total of 104 participants were selected for the study. There were 3 groups: Group I: 3rd and 4th year dental students and interns (n = 40); Group II: postgraduates (n = 34); Group III: senior residents and faculty members (≥ 6 years of clinical experience) (n = 30). All participants were evaluated for congenital color blindness with Ishihara plates, their dominant eye with Mile's test, and their color perception with the Farnsworth-Munsell 100 hue test. The shade guide test was used for shade matching with a second corresponding set of Vitapan classical shade guides.

Results

The results of Mile's test revealed that 60.6% were right-eye dominant and 39.4% were left-eye dominant. There was a statistically significant difference among all participants between the dominant eye and the non-dominant eye in shade matching.

Conclusions

The dominant eye has a positive effect on shade matching and the ability to match shades becomes better with an increase in clinical experience.

Prediction of patient's neurological recovery from cervical spinal cord injury through XGBoost learning approach

Due to the diversity of patient characteristics, therapeutic approaches, and radiological findings, it can be challenging to predict outcomes based on neurological consequences accurately within cervical spinal cord injury (SCI) entities and based on machine learning (ML) technique. Accurate neurological outcomes prediction in the patients suffering with cervical spinal cord injury is challenging due to heterogeneity existing in patient characteristics and treatment strategies. Machine learning algorithms are proven technology for achieving greater prediction outcomes. Thus, the research employed machine learning model through extreme gradient boosting (XGBoost) for attaining superior accuracy and reliability followed with other MI algorithms for predicting the neurological outcomes. Besides, it generated a model of a data-driven approach with extreme gradient boosting to enhance fault detection techniques (XGBoost) efficiency rate. To forecast improvements within functionalities of neurological systems, the status has been monitored through motor position (ASIA [American Spinal Injury Association] Impairment Scale [AIS] D and E) followed by the method of prediction employing XGBoost, combined with decision tree for regression logistics. Thus, with the proposed XGBoost approach, the enhanced accuracy in reaching the outcome is 81.1%, and from other models such as decision tree (80%) and logistic regression (82%), in predicting outcomes of neurological improvements within cervical SCI patients. Considering the AUC, the XGBoost and decision tree valued with 0.867 and 0.787, whereas logistic regression showed 0.877. Therefore, the application of XGBoost for accurate prediction and decision-making in the categorization of pre-treatment in patients with cervical SCI has reached better development with this study.

Complex-compound Odontome with 526 Denticles: A Unique Case Report

Aim

To report a unique case presentation of a complex-compound odontome with 526 denticles.

Background

Odontoma is a hamartoma of the jaws that has both epithelial and mesenchymal components differentiating to form enamel and dentin. It is of compound and complex types. Rarely, the features of both the types are present together in what is called the compound-complex type of odontoma.

Case description

The case report discussed here is that of a 7-year-old boy who presented with a compound-complex odontoma in the right posterior mandibular region.

Conclusion

Timely diagnosis and prompt surgical treatment aid in preventing complications and bony expansion. Thus, proper histopathological examination is essential for the confirmation of odontoma. Recurrence of odontoma is rare and usually has a favorable prognosis if diagnosed early.

Clinical significance

The odontome contained 526 denticles, the maximum reported in the literature so far, making this a case of extreme clinical significance.

How to cite this article

Marimuthu M, Prabhu AR, Kalyani P, et al. Complex-compound Odontome with 526 Denticles: A Unique Case Report. Int J Clin Pediatr Dent 2022;15(6):789-792.

A phytomass-inspired carbon and its importance as an antibacterial agent against human pathogens

Background

Imprudent use of antimicrobial drugs has resulted in the microbial resistance among the known microbes and hence we foresee a pressing need towards the development of novel, low-cost, and high potent antimicrobials which should be munificent by nature. In the pursuit of the above, phosphoric acid activated low-cost carbon was produced from a renewable phytomass precursor viz., leaves of Vitex negundo L. plant and explored for its antibacterial efficacy against four human pathogens viz., S. aureus, S. pyogenes (Gram-positive bacteria), and E. coli, P. aeruginosa (Gram-negative bacteria) by adopting well diffusion method. Carbon yield, burn-off, phase purity, elemental composition, particle morphology, and surface functionalities have been studied by ultimate elemental analysis, X-ray diffractometry, elemental analysis, scanning electron microscopy, and Fourier transform infrared spectrophotometry respectively. Minimal inhibition concentration (MIC) was also followed. Plausible mechanism of killing the pathogens by the above activated carbon was also provided.

Results

Vitex negundo leaves derived activated carbon (VNLAC) was found to contain large number of O-, S- and N-containing surface groups which are supposedly responsible for bestowing antibacterial properties to the carbon derived from Vitex negundo leaves. It has emerged as a potential antibacterial agent for many Gram-negative as well as Gram-positive bacteria. The inhibition zone of mean diameters ranged from 9 to 25 mm against all the pathogens was significantly (p < 0.05) less than that of the control viz., ciprofloxacin. Thus, the fundamental experimental results may extend the limits of carbon sources but also the conventional idea of obtaining active carbon to apply in technologies where carbon is inevitable.

Conclusion

The work not only demonstrates the promising potential of VNLAC as an efficient antibacterial agent but also presents a feasible mechanism of action of removing pathogens. Vitex negundo-derived carbon may become a cheap substitute for cost-prohibitive drugs. The findings of the work illustrate an easy choice as an antibacterial for topical application at infected sites.

Oncogenes and their Role in Oral Oncogenesis - A Survey

Background: Oral squamous cell carcinoma [OSCC] is the most common malignancy of the oral cavity. The etiological agents for OSCC are tobacco, betel quid, smoking, and alcohol. Oral cancer also has a genetic basis that is mediated by oncogenes.  Aim: The aim of the survey was to evaluate the knowledge about the role of oncogenes in oral oncogenesis among undergraduate dental students.  Materials and Methods: The study was a questionnaire-based survey and the respondents were to fourth year or interns of an undergraduate dental school. The sample size of the study was 100 and simple random sampling was used for choosing the sample population. The collected data was validated, tabulated, and analyzed with Statistical Package for Social Sciences for Windows, version 20.0 (SPSS Inc., Chicago, IL, USA), and results were obtained. Results and Conclusion: 25% of the respondents were fourth-year students and 75% were interns. About 98% of respondents were aware of the genetic basis of oral cancer. However, their knowledge about the role of oncogenes in oral cancer was very limited. A statistically significant association [P<0.05] was seen between the year of study and knowledge about oncogenes. Hence, measures have to be taken to impart knowledge about oncogenes for better diagnosis and targeted therapy.

Platelet Rich Plasma - Platelet Counts and Application - A Literature Review

Platelet rich plasma (PRP) is a novel method of using plasma concentrated with platelets for wound healing and tissue regeneration. Platelet rich plasma is prepared from the venous blood using a differential centrifugation technique. It involves a separation spin and a concentration spin, yielding platelet rich plasma. PRP products have been classified into 4 types depending upon major cell constituent and fibrin density upon activation. These are as follows: Pure PRP, Leukocyte and PRP, Pure PRF, Leukocyte and PRF. PRF differs from PRP in that it is rich in a high density fibrin network after activation. PRP is abundant in a variety of growth factors such as VEGF, PDGF, TGF, EGF, and Interleukin-1. Literature consists of reports by different authors about the platelet yield of PRP centrifuged by different systems. A number of factors have also been quoted to influence the platelet concentration in platelet rich plasma. Hence, the aim of this review is to discuss the platelet concentration in PRP centrifuged by different systems and to observe for variations if any.

Conjugation of ampicillin and enrofloxacin residues with bovine serum albumin and raising of polyclonal antibodies against them

AIM

The aim of this study is to test the potency of bovine serum albumin (BSA) conjugated ampicillin (AMP) and enrofloxacin (ENR) antigens in eliciting an immune response in rats using indirect competitive enzyme-linked immunosorbent assay (icELISA).

MATERIALS AND METHODS

AMP and ENR antibiotics were conjugated with BSA by carbodiimide reaction using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as a cross-linker. The successful conjugation was confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Sprague-Dawley rats were immunized with the conjugates and blood samples were collected serially at 15 days time interval after first immunization plus first booster, second booster, third booster, and the fourth sampling was done 1½ month after the third booster. The antibody titres in the antisera of each antibiotic in all the four immunization cycles (ICs) were determined by an icELISA at various serum dilutions ranging from 1/100 to 1/6400.

RESULTS

Analysis of antibiotic-BSA conjugates by sodium dodecyl sulfate polyacrylamide gel electrophoresis and coomassie blue staining revealed high molecular weight bands of 85 kDa and 74 kDa for AMP-BSA and ENR-BSA respectively when compared to 68 kDa band of BSA. Both the antibiotic conjugates elicited a good immune response in rats but comparatively the response was more with AMP-BSA conjugate than ENR-BSA conjugate. Maximum optical density 450 value of 2.577 was recorded for AMP-BSA antisera, and 1.723 was recorded for ENR-BSA antisera at 1/100(th) antiserum dilution in third IC.

CONCLUSION

AMP and ENR antibiotics proved to be good immunogens when conjugated to BSA by carbodiimide reaction with EDC as crosslinker. The polyclonal antibodies produced can be employed for detecting AMP and ENR residues in milk and urine samples.

Correlation Analysis in the Benzylation of Sulfur Nucleophiles

In the nucleophilic substitution reaction of benzyl bromides with three sulfur nucleophiles a linear relationship between the nucleophile discrimination parameter (s) and the Hammett substituent constant (σ) is observed.

Decavanadate possesses alpha-adrenergic agonist activity and a structural motif common with trans-beta form of noradrenaline

Decavanadate, an inorganic polymer of vanadate, produced contraction of rat aortic rings at a relatively high concentration compared to phenylephrine, an agonist of alpha-adrenergic receptor. This effect was blocked by two known alpha-adrenergic receptor antagonists, prazosin and phenoxybenzamine. Decavanadate, formed by possible dimerization of V5 under acid conditions, possessed a structural feature of two pairs of unshared oxygen atoms at a distance of 3.12 A, not found in its constituents of V4 or V5. A structural motif of O..O..O using such oxygen atoms is recognized in decavanadate. This matches with a similar motif of N..O..O that uses the essential amino and hydroxyl groups of the side-chain and the m-hydroxyl group in trans-beta form of noradrenaline. The interaction of such a structural motif with the membrane receptor is likely to be the basis of the unusual noradrenaline-mimic action of decavanadate.

NADH oxidation is stimulated by an intermediate formed during vanadyl-H2O2 interaction

Addition of NADH decreased the oxygen release that accompanied oxidation of vanadyl by H2O2. The added NADH was oxidized rapidly and oxygen was consumed with a stoichiometry of 1:1 for NADH/O2. Small concentrations of H2O2 were sufficient to trigger this oxygen-consuming NADH oxidation which terminated on exhaustion of either NADH or vanadyl. The oxidation of NADH increased proportionately with concentration of NADH and vanadyl. The oxidation products of vanadyl were found to be a mixture of vanadate oligomers and peroxovanadates. The reaction was sensitive to catalase, SOD, histidine and EDTA. Using ESR spectroscopy with DMPO as the spin trap, an adduct corresponding to DMPO-OH was detected in these phosphate-buffered reaction mixtures. Participation of hydroxyl radicals in NADH oxidation, however, seems doubtful because even high concentrations of ethanol, methanol, mannitol, formate and benzoate, known to scavenge these radicals, did not block the reaction. The results indicate that peroxovanadate intermediates formed during vanadyl oxidation by H2O2 play a key role in the oxidation of NADH.

A novel phenomenon of burst of oxygen uptake during decavanadate-dependent oxidation of NADH

Oxidation of NADH by decavanadate, a polymeric form vanadate with a cage-like structure, in presence of rat liver microsomes followed a biphasic pattern. An initial slow phase involved a small rate of oxygen uptake and reduction of 3 of the 10 vanadium atoms. This was followed by a second rapid phase in which the rates of NADH oxidation and oxygen uptake increased several-fold with a stoichiometry of NADH: O2 of 1:1. The burst of NADH oxidation and oxygen uptake which occurs in phosphate, but not in Tris buffer, was prevented by SOD, catalase, histidine, EDTA, MnCl2 and CuSO4, but not by the hydroxyl radical quenchers, ethanol, methanol, formate and mannitol. The burst reaction is of a novel type that requires the polymeric structure of decavanadate for reduction of vanadium which, in presence of traces of H2O2, provides a reactive intermediate that promotes transfer of electrons from NADH to oxygen.

Polyvanadate-stimulated NADH oxidation by plasma membranes--the need for a mixture of deca and meta forms of vanadate

Polyvanadate solutions obtained by extracting vanadium pentoxide with dilute alkali over a period of several hours contained increasing amounts of decavanadate as characterized by NMR and ir spectra. Those solutions having a metavanadate:decavanadate ratio in the range of 1-5 showed maximum stimulation of NADH oxidation by rat liver plasma membranes. Reduction of decavanadate, but not metavanadate, was obtained only in the presence of the plasma membrane enzyme system. High simulation of activity of NADH oxidation was obtained with a mixture of the two forms of vanadate and this further increased on lowering the pH. Addition of increasing concentrations of decavanadate to metavanadate and vice versa increased the stimulatory activity, reaching a maximum when the metavanadate:decavanadate ratio was in the range of 1-5. Increased stimulatory activity can also be obtained by reaching these ratios by conversion of decavanadate to metavanadate by alkaline phosphate degradation, and of metavanadate to decavanadate by acidification. These studies show for the first time that both deca and meta forms of vanadate present in polyvanadate solutions are needed for maximum activity of NADH oxidation.

Characterization of oxygen free radicals generated during vanadate-stimulated NADH oxidation

The oxidation of NADH and accompanying reduction of oxygen to H2O2 stimulated by polyvanadate was markedly inhibited by SOD and cytochrome c. The presence of decavanadate, the polymeric form, is necessary for obtaining the microsomal enzyme-catalyzed activity. The accompanying activity of reduction of cytochrome c was found to be SOD-insensitive and therefore does not represent superoxide formation. The reduction of cytochrome c by vanadyl sulfate was also SOD-insensitive. In the presence of H2O2, all the forms of vanadate were able to oxidize reduced cytochrome c, which was sensitive to mannitol, tris and also catalase, indicating H2O2-dependent generation of hydroxyl radicals. Using ESR and spin trapping technique only hydroxyl radicals, but not superoxide anion radicals, were detected during polyvanadate-dependent NADH oxidation.