Regioselective ring opening of aziridine for synthesizing azaheterocycle.

Aziridine had different regioselective ring openings depending on the functional group of its alkyl substituent. In the case of the alkyl group bearing γ-ketone at the C2 substituent of aziridine, the ring opening by the hydroxy nucleophile from H2O occurred by attacking the aziridine carbon at the C2 position. This reaction proceeded efficiently in the presence of CF3CO2H. Interestingly, the same starting aziridine ring bearing the alkyl substituent at the C2 position with the γ-silylated hydroxy group instead of γ-ketone led to the ring-opening reaction by the same oxygen nucleophile at the unsubstituted C3 position, with the breakage of the bond between aziridine N1 nitrogen and carbon at C3. These reaction products were cyclized to afford substituted pyrrolidine and piperidine rings with representative examples of congeners of pseudoconhydrine and monomorine.

Magnitude and Impact of Workplace Violence Against Obstetric Healthcare Personnel: A Multicentre Cross-Sectional Study.

Background: Workplace violence is defined by the World Health Organization (WHO) as incidents where staff is abused, threatened or assaulted in work settings. In emergency predominated branch like obstetrics, there is a need to study the magnitude and impact of violence against healthcare workers (HCW). Materials and Methodology: This cross-sectional study was conducted in the Department of Obstetrics at 2 centres in Lucknow district, for a period of 6 months. The study population included trainee residents, senior residents, nursing staff and consultants. Standard definitions from the WHO were used to define the types of violence. The validated questionnaire was designed in English with 25 questions to understand the incidence of workplace violence, prevention policy, reporting and follow-ups of incidents and impact of violence. Results: With a response rate of 90%, 274 HCW participated in the study. In total, 172 HCW (62.7%) either faced physical or verbal assault. In 70% of incidents, patient, their relatives or public were perpetrators of violence, and the rest 30% incidents were by colleagues or management. Majority of the incidents were in emergency areas. Only 22% of the abused reported to the concerned authorities. At least 123 (71.5%) HCW were extremely dissatisfied with the action taken. Action was taken against only 9.8% of the perpetrators. None of the respondents received any training to handle workplace violence. Conclusion: There is an alarming high prevalence of workplace violence by patients and colleagues. Adequate training to handle these incidents, improvement of working environment and unconditional support from management will bring a positive work experience. Supplementary Information: The online version contains supplementary material available at 10.1007/s13224-023-01809-0.

Reliability of three pain assessment tools in children requiring dental treatment: A comparative clinical study.

Background: The appropriate intervention of pain is based on its accurate evaluation, which is a challenge in the pediatric population as they often do not have the language development or cognitive sophistication to describe it correctly. Untreated pain has a negative impact on the psychosocial well-being of children. Aim and Objectives: The study aimed to evaluate and compare the reliability of different pain assessment scales, namely, the Wong Baker Facial Pain Rating scale (WBFPS), Modified Emoji Pain Scale (MEPS), and indigenously developed indigenously made GIF Pain Scale (SPGPS) in children undergoing dental treatment under local anesthesia (LA). Materials and Methods: The study included 152 children aged 4-6 years with a Frankl behavior rating of score 3 and 4 (positive and definitely positive) requiring dental treatment under LA. After local infiltration, each child with two independent observers was asked to record the response of the current pain on the WBFPS, MEPS, and SPGPS. The reliability of the pain scales was assessed on the basis of similar responses given by all three individuals. Results: The Pearson correlation test was performed to determine the correlation among the scales. A very strong correlation was found between the WBFPS and SPGPS (r = 0.848), while a moderate correlation was found among the WBFPS and MEPS (r = 0.691). A strong correlation was found between the SPGPS and MEPS (r = 0.723). Conclusion: The SPGPS proved to be a more reliable pain assessment tool compared to the WBFPS and MEPS in clinical pediatric dentistry.

Tobacco cessation center in a dental college: An 8 year institution-based study.

Background: Oral cancer is a major health concern in the Indian subcontinent, where it ranks among the top three types of cancer in the country. Tobacco and its products have been implicated as a major etiologic factor behind cancers. It is believed that tobacco is an epidemic in itself taking the death toll to 7 million globally. In India alone, mortality because of tobacco is more than 1.3 million. Dentists are the first to notice any change in the oral cavity or come across any suspicious looking oral lesion and therefore are instrumental in primary prevention and care. Methods: The present study data are of the patients enrolled in a Tobacco Cessation Center(TCC) at a Dental College in Meerut in Meerut from May 2012 (since its inception) to March 2020. The following methods of counseling were carried out: group counseling, interactive sessions, audio-visual aids, and individual counseling sessions. Self-training for oral cavity examination was also given after every group counseling session. Behavioral counseling and pharmacological intervention were given as per Fagerström Test for Nicotine Dependence (FTND) score. At the end of 1 year, patients who quit were graded into 0, 1, and 2, with 0 for those who failed to quit, 1 for those who did completely quit, and 2 for those who reduced their habit by more than 50%. Results: The quit rate achieved was 57.6% (complete responders -43.2% and partial responders 14.4%). The relapse reported was 1.8%. Conclusion: A Tobacco cessation Center set up in a Dental College could be of great help in the primary prevention of oral cancer and can bring a drastic increase in quit rates. Proper counseling skills once nurtured in young under-graduates can boost the tobacco-free India campaign.

Comparative evaluation of antibacterial efficacy of active oxygen containing versus other dentifrices against Streptococcus mutans count in children with early childhood caries: A clinico-microbiological study.

Background: Fluoridated dentifrices have been used for the prevention of dental caries since ages. However, to avoid the risk of fluorosis, the use of newer nonfluoridated options in dentifrices has shown a great interest in reducing Streptococcus mutans (SM) in early childhood caries (ECC). Aim: The study aimed to evaluate the antimicrobial efficacy of active oxygen (AO)-based dentifrice with amine fluoride (AF)-, sodium monofluorophosphate (SMP)-, herbal (HB)-, and tricalcium phosphate (TCP)-based dentifrices on SM count in children with ECC. Materials and Methods: Two hundred and fifty children aged 3-6 years with def ≥4 were selected and randomly divided into five groups of 50 each, based on the type of dentifrices used; Group I: AO-based, Group II: TCP, Group III: SMP, Group IV: AF, and Group V: HB dentifrice, and were asked to brush twice daily for 15 days. The saliva samples were collected at baseline, and after 15 days, cultured for SM colonies count. Results: Difference in colony-forming units (CFU)/ml between baseline and 15 days was highly significant in all the five groups (P < 0.001). Significant difference was observed in SM count after 15 days between Groups I and IV (P = 0.017), while nonsignificant differences were seen when compared with Groups II, III, and V (P = 0.975, 0.137, and 0.992). Conclusions: All the dentifrices were efficacious in reducing SM count in children with ECC. Although AO dentifrice showed superior results when compared to SMP, TCP, and HB, it did not prove to be superior to AF.

Peripheral cemento-ossifying fibroma - A rare case report.

Peripheral cemento-ossifying fibroma (PCOF) is a relatively rare tumor classified between fibro-osseous lesions. PCOF is an osteogenic neoplasm that ordinarily presents as an epulis-like growth with uncertain pathogenesis. It predominantly affects young adults, with peak prevalence between the first and second decades of life. We present here the case report of a 15-year-old girl, which was previously surgically excised twice and had recurred both the times. The disease duration was 2 years and a follow-up of 1-year was done. Clinical, radiographic, and histological characteristics are discussed with recommendations regarding the treatment is provided.

Preparation of Enantiopure Non-Activated Aziridines and Synthesis of Biemamide B, D, and epiallo-Isomuscarine.

Nitrogen-containing heterocycle aziridines are synthetically very valuable for the preparation of azacyclic and acyclic molecules. However, it is very difficult and laborious to make aziridines in optically pure forms on a large scale to apply asymmetric synthesis of aza compounds. Fortunately, we successfully achieved both enantiomers (2R)- and (2S)-aziridine-2-carboxylates with the electron-donating α-methylbenzyl group at the ring nitrogen as non-activated aziridines. These starting aziridines have two distinct functional groups-highly reactive three-membered ring and versatile carboxylate. They are applicable in ring-opening or ring-transformation with aziridine and in functional group transformation to others from carboxylate. Both of these enantiomers were utilized in the preparation of biologically important amino acyclic and/or aza-heterocyclic compounds in an asymmetric manner. Specifically, this report describes the first expedient asymmetric synthesis of both enantiomers of 5, 6-dihydrouracil-type marine natural products biemamide B and D as potential TGF-ß inhibitors. This synthesis consisted of regio- and the stereoselective ring-opening reaction of aziridine-2-carboxylate and subsequent formation of 4-aminoteterahydropyrimidine-2,4-dione. One more example in this protocol dealt a highly stereoselective Mukaiyama reaction of aziridine-2-carboxylate and silyl enol ether, following intramolecular aziridine ring-opening to provide easy and facile access to (-)-epiallo-isomuscarine.

Finite free convolutions of polynomials.

We study three convolutions of polynomials in the context of free probability theory. We prove that these convolutions can be written as the expected characteristic polynomials of sums and products of unitarily invariant random matrices. The symmetric additive and multiplicative convolutions were introduced by Walsh and Szegö in different contexts, and have been studied for a century. The asymmetric additive convolution, and the connection of all of them with random matrices, is new. By developing the analogy with free probability, we prove that these convolutions produce real rooted polynomials and provide strong bounds on the locations of the roots of these polynomials.

Efficacy of Root Canal Instrumentation and Fracture Strength Assessment in Primary Molars after Preparing Two Different Shapes of Access Cavity: An Ex Vivo Histological Study.

AIM AND OBJECTIVE: To evaluate the efficacy of root canal instrumentation and fracture strength assessment in primary molars after preparing different shapes of access cavity design. MATERIALS AND METHODS: Sixty extracted primary mandibular molars with at least 2/3rd roots were randomly, equally divided into two groups based on shapes of the access cavities; Group I: Traditional access cavity (TAC), Group II: Conservative access cavity (CAC). Each group was further subdivided into two subgroups with 15 samples each. After, root canal debridement, samples in subgroup 1 were sectioned for histological evaluation of root canal instrumentation efficacy, while subgroup 2 were assessed for fracture strength using a Universal Testing Machine. The data were analyzed statistically using Mann-Whitney and post hoc Tukey tests, with a p value <0.05. RESULTS: Traditional access cavity showed statistically significant root canal debridement efficacy (p < 0.05) compared with CAC. Statistically significant differences were obtained between fracture strength values among the two groups (p < 0.05), with considerably higher fracture strength in the CAC group than TAC. CONCLUSION: Traditional access cavity design resulted in complete root canal debridement but caused weakening of tooth structure due to low fracture strength, necessitating the use of full coverage restoration postendodontic therapy. HOW TO CITE THIS ARTICLE: Singhal Y, Srivastava N, Rana V, et al. Efficacy of Root Canal Instrumentation and Fracture Strength Assessment in Primary Molars after Preparing Two Different Shapes of Access Cavity: An Ex Vivo Histological Study. Int J Clin Pediatr Dent 2021;14(4):518-524.

Total crown replacement technique: A biological treatment option for grossly destructed primary molars.

BACKGROUND: Restoration of severely damaged primary molars with very short clinical crowns is a big challenge and often extracted due to the lack of restorative options. Total crown replacement (TCR) is a novel treatment alternative for the restoration of such teeth through bonding of the biological restorations which are the sterile decoronated crowns of the extracted human teeth, obtained from a tooth bank. CASE REPORT: Presented here is a report of two cases restored with the TCR technique. A 9-month follow-up showed satisfactory results in terms of function, esthetics, gingival health, and morphology including occlusal wear. TCR can be a viable and economical alternative for restoration of severely decayed/damaged primary teeth, otherwise indicated for extraction.

Comparison of Preemptive Effect of Dexamethasone and Methylprednisolone After Third Molar Surgery: A Split-Mouth Randomized Triple-Blind Clinical Trial.

AIM: The study aimed to compare the efficacy of methylprednisolone and dexamethasone injected into masseter muscle preoperatively in surgical extraction of lower third molars. MATERIALS AND METHODS: This study was carried out on 20 patients who reported to the department of Oral and Maxillofacial surgery, Sri Rajiv Gandhi College of Dental Sciences and Hospital Bangalore, requiring surgical removal of bilateral mandibular third molars. The efficacy of corticosteroid was evaluated based on its ability to reduce pain, swelling and trismus following the surgical extraction of impacted lower third molars. RESULTS: There was no statistical difference between the two steroids with both of them achieving equal level of pain control. There was a statistically significant difference on the second postoperative day with dexamethasone showing clinically superior result. The difference in oral aperture was found to be statistically significant with dexamethasone showing a decreased reduction in postoperative mouth opening on both second and seventh day. CONCLUSION: This study conclusively proves that patient comfort levels are far better with the use of dexamethasone.

Comparison of the Conventional Band and Loop Space Maintainers with Modified Space Maintainers: A Split-mouth Randomized Clinical Trial.

AIM AND BACKGROUND: Space maintainers (SMs) are used to preserve space created by premature loss of primary teeth. The most commonly used band and loop (B&L) SMs have several demerits, e.g., non-functional, poor gingival health, limited survival, laboratory work for fabrication and multi-sitting procedure, etc. This study aimed to compare the efficacy of conventional B&L SMs with conventional tube and loop (CTL), bonded tube and loop (BTL) and bonded B&L in terms of gingival health, survival time, and patients' and parents' satisfaction. MATERIALS AND METHODS: Fifteen children between 4 years and 8 years of age with at least two fresh extraction sites of primary molars contra- or bilaterally in each child (total 30 fresh extraction sites) were included in the study. Conventional B&L on one site while bonded loop (BL)/CTL or BTL on the other site were delivered, based on random allocation. An evaluation was done at 1st, 3rd, 6th, and 9th months for survival time, gingival health, and patients'/parents' satisfaction. Results were statistically analyzed using independent t-test and Chi-square test under SPSS version 20.0 software. RESULTS: 100% B&L and CTL while only 60% BL and 80% BTL survived till the end of the study. For gingival health, statistically significant differences were obtained at 1st, 3rd, 6th, and 9th month's intervals (p < 0.05) when CTL was compared with B&L, BL, and BTL. In terms of patients' acceptance, all the SMs were well accepted by the patients. However, on the intergroup comparison, patients' acceptance was higher with bonded SMs. CONCLUSION: Conventional tube and loop SMs were found to be most efficacious in terms of survival time, gingival health, and patients' satisfaction. CLINICAL SIGNIFICANCE: To find a better alternative for the conventional B&L SMs. HOW TO CITE THIS ARTICLE: Tyagi M, Rana V, Srivastava N, et al. Comparison of the Conventional Band and Loop Space Maintainers with Modified Space Maintainers: A Split-mouth Randomized Clinical Trial. Int J Clin Pediatr Dent 2021;14(S-1):S63-S68.

Effectiveness of different behavior guidance techniques in managing children with negative behavior in a dental setting: A randomized control study.

BACKGROUND: Dental fear is a common cause of uncooperative behavior among young children, which poses a challenge in providing effective dental treatment. With the advancements in technology, several behavior guidance techniques in the form of distraction have emerged over time for managing uncooperative pediatric dental patients. AIM: The aim of this study is to compare and evaluate the effectiveness of four different behavior guidance techniques in managing uncooperative pediatric patients by measuring pre- and post-operative dental fear/anxiety levels using physiological and nonphysiological parameters. METHODOLOGY: Sixty systemically healthy children aged 5-8 years with negative behavior as per Frankl's Rating Scale, requiring restoration were included in the study and randomly divided into four equal groups (n = 15), based on the guidance techniques used: Tell-Show-Do (TSD) as a control group and audio distraction, audiovisual distraction (AVD) (virtual reality [VR]) and Mobile Phone Game Distraction as test groups. Pre- and post-intervention levels of the child's fear/anxiety were assessed using both physiological (blood pressure and pulse rate) and nonphysiological (facial image scale) parameters. The data were evaluated using t-test and one-way ANOVA test. RESULTS: A statistically significant difference was observed in both physiological and non-physiological parameters post-intervention in the groups with a maximum decrease in the AVD (VR) group. CONCLUSIONS: AVD (VR) was found to be the most effective while TSD alone as the least effective behavior guidance technique in reducing dental fear/anxiety in uncooperative pediatric dental patients.

Genetic Association of ACE2 rs2285666 Polymorphism With COVID-19 Spatial Distribution in India.

Studies on host-pathogen interaction have identified human ACE2 as a host cell receptor responsible for mediating infection by coronavirus (COVID-19). Subsequent studies have shown striking difference of allele frequency among Europeans and Asians for a polymorphism rs2285666, present in ACE2. It has been revealed that the alternate allele (TT-plus strand or AA-minus strand) of rs2285666 elevate the expression level of this gene upto 50%, hence may play a significant role in SARS-CoV-2 susceptibility. Therefore, we have first looked the phylogenetic structure of rs2285666 derived haplotypes in worldwide populations and compared the spatial frequency of this particular allele with respect to the COVID-19 infection as well as case-fatality rate in India. For the first time, we ascertained a significant positive correlation for alternate allele (T or A) of rs2285666, with the lower infection as well as case-fatality rate among Indian populations. We trust that this information will be useful to understand the role of ACE2 in COVID-19 susceptibility.

Stereoselective synthesis of 2,6-disubstituted piperidine alkaloids.

Among the large number of structurally diverse alkaloids, 2,6-disubstituted piperidine and its analogs have often been targeted when exploiting new synthetic techniques perhaps because of their strong pharmacological properties. This review outlines synthetic strategies to build the 2,6-disubstituted piperidine structural motif with a focus on stereochemical control of two substituents at C2 and C6. The key reactions in this process are then classified on the basis of how the piperidine rings were built with specific examples of natural products that control the stereochemical outcomes and their transition states.

Assessment of Intraoral Findings of Neonates, Born in and around Meerut City.

AIM: The aim of this study is to evaluate the occlusal relationships between the gum pads of neonates and to record intraoral findings in neonates and compare with the existing findings. MATERIALS AND METHODS: The oral cavities of 1,000 healthy neonates from birth to 1 month of age were examined to evaluate the occlusal relationships between the gum pads and to record other intraoral findings in neonates and compare with the existing findings. Oral findings recorded were oral mucosal cysts, Fordyce's spot, Epstein's pearls, Bohn's nodules, ankyloglossia, natal or neonatal teeth and attachment of the upper midline frenum. Relationship between the alveolar ridges was also recorded. Obtained data were evaluated and statistically analyzed using the Statistical Package for Social Sciences (SPSS) version 21.0 and Epi-info version 3.0. RESULTS: The maxillo-mandibular relationship of gum pads in approximately 97% cases, the mandible was found distal and lingual to maxilla. The presence of anterior open bite was observed in 9.1% cases. The most common intraoral finding in examined neonates was an oral mucosal cyst, 61.2%. The presence of Epstein's pearls was the next most common finding 38.3%. Fordyce's spots were found only in 1.2% of cases, while the presence of natal/neonatal teeth was only in 0.6% of cases. Ankyloglossia was present in only 0.5% neonates. Maxillary frenum was present in 79.1% of cases and it was attached on the alveolar crest. CONCLUSION: The results of the present study were in accordance with the pre-existing data. However, anterior open-bite was seen in significantly less percentage of the population. HOW TO CITE THIS ARTICLE: Niranjan MM, Srivastava N, Rana V, et al. Assessment of Intraoral Findings of Neonates, Born in and around Meerut City. Int J Clin Pediatr Dent 2020;13(1):48-52.

Clinical Evaluation of Restoration of Grossly Carious Primary Teeth Using Biological Approach.

BACKGROUND: To widen the treatment option of primary teeth with mutilated crown tooth structure but having more than two-thirds of root structure were restored by using natural tooth crowns with the help of adhesive materials. AIM AND OBJECTIVE: To restore the grossly decayed primary molars with biological crowns and to evaluate them for longevity, change in color, occlusal wear, marginal integrity, and patient/parent acceptance. MATERIALS AND METHODS: Twenty primary molars from 6 to 10 years old children were restored with biological crowns (extracted/exfoliated tooth crowns) and follow-up was done till 12 months. Data tabulated and results were statistically analyzed using Kaplan-Meier survival analysis. The statistical software SPSS 19.0 was used. RESULTS: 89.47% of biological restorations survived successfully till 12 months follow-up period. No occlusal wear was found in any of the samples, a breach in marginal integrity was seen only in 16.6% of cases, and only 5.5% of biological crowns showed discoloration (darker) at 12 months intervals. 65.00% of patients well accepted the treatment and showed satisfaction while 20.0% of patients remained neutral. Only 15% of patients experienced dissatisfaction at the end of the study. CONCLUSION: Biological restorations proved to be a viable alternative for the restoration of grossly mutilated primary molars. HOW TO CITE THIS ARTICLE: Singh P, Srivastava N, Rana V, et al. Clinical Evaluation of Restoration of Grossly Carious Primary Teeth Using Biological Approach. Int J Clin Pediatr Dent 2020;13(S-1):S55-S63.

Total Synthesis and Stereochemical Revision of Biemamides B and D.

The first expedient asymmetric synthesis of both enantiomers of 5,6-dihydrouracil-type marine natural products biemamides B and D was achieved from chiral 1-(α-methylbenzyl)aziridine-2-carboxylate. The key steps involved in the synthetic route are regio- and stereoselective aziridine ring opening via azide followed by a base-induced cyclization reaction. After comparison of ECD and optical rotation data of both synthetic enantiomers, the absolute configuration of natural biemamides B and D at the C5 position has been assigned as (-)-(5S), which is an enantiomer to the originally proposed structure (-)-(5R).

Compound Odontome: A Case Report.

INTRODUCTION: Odontomas generally appear as small, solitary, or multiple radio-opaque lesions found on routine radiographic examinations. Traditionally, odontomas have been classified as benign odontogenic tumors and are subdivided into complex or compound odontomas morphologically. Frequently, they interfere with the eruption of the teeth. CASE REPORT: This paper describes the case of a compound odontoma in a 10-year-old boy diagnosed after extraction of the retained right primary mandibular first molar in the radiograph. A surgical excision was performed and the histopathological examination revealed a compound odontome. CONCLUSION: Early diagnosis of odontomas and complete removal ensures better prognosis. HOW TO CITE THIS ARTICLE: Rana V, Srivastava N, et al. Compound Odontome: A Case Report. Int J Clin Pediatr Dent 2019;12(1):64-67.

Alkylative Ring-Opening of Bicyclic Aziridinium Ion and Its Application for Alkaloid Synthesis.

Alkylative ring-opening of bicyclic aziridinium ion generated from 4-hydroxybutylaziridine with organocopper reagent was achieved successfully to afford 2-alkylsubstituted piperidine in high or moderate yield. This method allowed carbon-carbon bond formation of "non-activated" aziridine via aziridinium ion ring-opening in regio- and stereo-selective manner for the first time. This newly developed reaction was applied for an efficient synthesis of alkaloid with the representative example of conine and epiquinamide.