Microstructural Evaluation of the Mineralized Apical Barrier Induced by a Calcium Hydroxide Paste Containing Iodoform: A Case Report.

INTRODUCTION: A 65-year-old man had nonsurgical retreatment using an iodoform and calcium hydroxide paste in a maxillary left canine with persistent apical periodontitis. An apical mineralized barrier (AMB) was observed 3-months postoperatively. Unfortunately, the tooth was extracted due to a cementum tear. This provided an opportunity to analyze the AMB histologically, as there is a lack of previous reports on its microstructure. METHODS: After extraction and removal of the granulation tissue from the root surface, the canine was processed, and observed using micro-computed tomography (µCT) and light microscopy. Thereafter, the specimen was resin-embedded specimen was evaluated by scanning electron microscopy, micro-X-ray fluorescence spectroscopy and Raman spectroscopy to understand the mechanism and nature of the AMB formation during apical healing. RESULTS: Nonsurgical retreatment was clinically successful based on the absence of clinical symptoms of apical periodontitis and the radiographic presence of an AMB. The AMB was opaque and could be readily differentiated from dentin under a light microscope. Micro-computed tomography analysis revealed that the AMB had the same mineral density as dentin. Scanning electron microscopy revealed that the AMB had two distinct layers based on the size of the calcified particles. Elemental mapping using micro-X-ray fluorescence spectroscopy showed that the localization of calcium and phosphorus differed between AMB and other areas of biomineralization. Raman spectral mapping revealed that the surface layer of the AMB consisted of collagen, calcium carbonate, and hydroxyapatite. CONCLUSIONS: This study explored new analytical methods for elucidating the apical wound-healing process and the nature of the mineralized repair. The findings provided detailed information on the AMB highlighting a bilaminar structure with high calcium components higher on the inside and a brightness similar to cementum not dentin and the presence of hydroxyapatite.

Efficacy of antibiotic and iodoform pastes in non-instrumental endodontic treatment of anterior primary teeth-Protocol for a randomized controlled clinical.

The maintenance of the deciduous tooth until its physiological exfoliation occurs is one of the main objectives of pediatric dentistry. Endodontic treatment in deciduous teeth resulting from carious or traumatic lesions with pulpal involvement is often necessary and we often find it difficult to perform it, due to the difficult control of the child, the internal anatomy of the root canals, and root resorptions. The non-instrumental endodontic treatment technique (NIET) associated with antimicrobial drugs has advantages such as shorter chair time and less complexity than the conventional technique in which root canal instrumentation is performed. The aim of this study is to carry out a controlled and randomized clinical trial to compare the effectiveness of (NIET) in primary teeth associated with the use of two obturator pastes. One hundred and twenty necrotic deciduous teeth of children aged between 3 and 6 years will be selected; and the teeth will be divided into two groups. In Group 1 and Group 2, root canals will not be instrumented, just irrigated and filled with the respective pastes, antibiotic (CTZ) and iodoform (Guedes-Pinto). Presence of fistula and mobility will be clinically evaluated. The evaluations will be carried out in both groups on the day of treatment and in periods of 1, 3 and 6 months after treatment. For the main outcome, the tooth will be the unit of analysis and the Kaplan-Meier test will be performed to estimate the survival rates of the included teeth. For comparison between the two groups, Student's t test or Mann-Whitney test will be performed, depending on the normality of the data. In addition, Poisson regression analyzes will be carried out, in order to allow the evaluation of the influence of some variables on the results. For all analyses, the significance value will be adjusted to 5%. Trial registration: NCT04587089 in ClinicalTrials.gov. Approval date: May 15, 2023.

One-pot Dess-Martin periodinane-mediated oxidative deprotection and olefination of trimethylsilyl-protected pyranosides and pyranoses.

The selective functionalization of carbohydrates provides a powerful method for introducing structural complexity, allowing access to unique drug scaffolds with distinctive pharmaceutical profiles. Herein, we describe an efficient and selective carbon-carbon bond forming reaction of a variety of common trimethylsilyl-protected pyranosides and pyranoses at C-6 using a one-pot Dess-Martin periodinane-mediated oxidation deprotection. This is followed by addition of stabilized and non-stabilized ylides to generate alkenoate carbohydrates and related analogs in good to moderate yields. We also report on the rapid deprotection of the remaining trimethylsilyl ether groups in near quantitative yields using an acidic resin-mediated ethanolysis.

Role of iodoform in jaw lesions: a systematic review.

Iodoform formulations are used as packing material following the surgical removal of jaw lesions. The purpose of this review was to explore the evidence and efficacy of iodoform-based dressings. We have systematically reviewed published articles according to the PRISMA statement. The search was conducted in PubMed, Google Scholar, Semantic Scholar, and the Cochrane Library database for articles mentioning the use of iodoform as dressing material for jaw lesions from January 2000 to March 2022. Finally, 92 studies were included. A total of 386 patients whose ages ranged from five months to 86 years (male n = 180, female n = 117). Different formulations of iodoform used were BIPP (n = 67), Whitehead's varnish (n = 17), iodoform (n = 7) and, iodine (n = 1) for its antiseptic properties. An iodoform impregnated gauze pack was changed once a week, most commonly, for a stipulated duration, until complete healing of the cavity. In the present review, iodoform was used, most commonly, in pathological cavities following surgical treatment of ameloblastoma and odontogenic keratocyst. Toxicity was reported in two studies. Based on the current review, iodoform is relatively safe and can be used in the management of extensive jaw lesions in which secondary healing is expected. Prospective and randomised control trials are recommended to assess the efficacy of various formulations and to delineate the timeframe for patient compliance.

Structure-Directing Interplay between Tetrel and Halogen Bonding in Co-Crystal of Lead(II) Diethyldithiocarbamate with Tetraiodoethylene.

The co-crystallization of the lead(II) complex [Pb(S2CNEt2)2] with tetraiodoethylene (C2I4) gave the co-crystal, [Pb(S2CNEt2)2]∙½C2I4, whose X-ray structure exhibits only a small change of the crystal parameters than those in the parent [Pb(S2CNEt2)2]. The supramolecular organization of the co-crystal is largely determined by an interplay between Pb⋯S tetrel bonding (TeB) and I⋯S halogen bonding (HaB) with comparable contributions from these non-covalent contacts; the TeBs observed in the parent complex, [Pb(S2CNEt2)2], remain unchanged in the co-crystal. An analysis of the theoretical calculation data, performed for the crystal and cluster models of [Pb(S2CNEt2)2]∙½C2I4, revealed the non-covalent nature of the Pb⋯S TeB (-5.41 and -7.78 kcal/mol) and I⋯S HaB (-7.26 and -11.37 kcal/mol) interactions and indicate that in the co-crystal these non-covalent forces are similar in energy.

Copper Hydride-Catalyzed Enantioselective Olefin Hydromethylation.

The enantioselective installation of a methyl group onto a small molecule can result in the significant modification of its biological properties. While hydroalkylation of olefins represents an attractive approach to introduce alkyl substituents, asymmetric hydromethylation protocols are often hampered by the incompatibility of highly reactive methylating reagents and a lack of general applicability. Herein, we report an asymmetric olefin hydromethylation protocol enabled by CuH catalysis. This approach leverages methyl tosylate as a methyl source compatible with the reducing base-containing reaction environment, while a catalytic amount of iodide ion transforms the methyl tosylate in situ into the active reactant, methyl iodide, to promote the hydromethylation. This method tolerates a wide range of functional groups, heterocycles, and pharmaceutically relevant frameworks. Density functional theory studies suggest that after the stereoselective hydrocupration, the methylation step is stereoretentive, taking place through an SN2-type oxidative addition mechanism with methyl iodide followed by a reductive elimination.

A Comparative Study on Alvogyl and a Mixture of Black Seed Oil and Powder for Alveolar Osteitis: A Randomized Double-Blind Controlled Clinical Trial.

Introduction: Alveolar osteitis (AO) is the most common complication faced by exodontia patients and is usually seen 24-74 hours after tooth extraction, heralded by severe throbbing pain. Nigella sativa is commonly known as black seed known to have anti-inflammatory and antibacterial properties along with other reparative properties that enhance bone formation. This study aimed to evaluate and compare the effects of Alvogyl and a mixture of Nigella sativa powder and oil in the treatment of dry sockets. Materials and Methods: Sixty patients above the age of 18 and below 70 years, from both genders, who underwent extraction of teeth and were clinically diagnosed with a dry socket at the clinic of the College of Dentistry, Jouf University, Saudi Arabia, were included in this study. Pain scores were assessed after placement of the dressing at the following intervals: 5 minutes, 30 minutes, 60 minutes, 2nd day, 4th day, and 7th day. Patients were randomly allocated to three groups, namely, Group 1 (Alvogyl), Group 2 (mixture of Nigella sativa's powder and oil), and Group 3 (control). Pain relief and healing of the socket were compared between the three groups. The collected data were subjected to statistical analysis through Spearman's correlation test, independent t-test, ANOVA, and post hoc test. Results: A mixture of Nigella sativa powder and oil showed a statistically significant difference in relieving pain compared to the Alvogyl group. A mixture of Nigella sativa's powder and oil required fewer dressings when compared to the Alvogyl group. Conclusion: A mixture of Nigella sativa powder and oil is the more efficacious dressing material for the management of dry sockets compared to Alvogyl. It provides immediate and complete pain relief and fewer numbers of repeated visits.

Single-Micelle and Single-Zinc-Particle Imaging Provides Insights into the Physical Processes Underpinning Organozinc Reactions in Water.

Micelles on the surfaces of individual metallic zinc particles are imaged by fluorescence microscopy with sensitivity up to single micelles. These micelles are made fluorescent to enable imaging, through the incorporation of boron dipyrromethene fluorophores as representative organic molecular "cargo". Highlighting an advantage of this in situ and sensitive fluorescence technique, the same micelles are not visible by ex situ scanning electron microscopy/energy dispersive X-ray spectroscopy analysis. Examination of micellar solutions with zinc reveals an aging process: micelles do not immediately adhere to the zinc surfaces upon mixing but rather build up over time. Furthermore, at longer times, smaller zinc particles become fully encased in micelle "shells". Once adhered, micelles remain in the local regions of the zinc surface for the duration of the imaging experiments (>2 h). Single micelles are imaged in solution, and their molecular contents are characterized. Two-color fluorescence crossover experiments show that micelles adhered to the surface of the zinc exchange molecular contents with micelles in solution, achieving molecular exchange equilibrium in ∼2.5 h. Unique (non-ensemble averaged) exchange kinetics are displayed by micelles at different locations on the zinc surface, consistent with exchange kinetics of single micelles or small local clusters of micelles. The aging of the micellar solutions and the rate of exchange while on the surface of the zinc suggest that micelle mass transport processes may contribute to overall reaction barriers in sustainable organozinc cross-coupling reactions in micellar water. The observed aging of the system suggests routes for improvement of preparative, bench-scale synthetic reactions involving micellar preparations of organozinc compounds.

Chemoselective and Diastereoselective Synthesis of C-Aryl Nucleoside Analogues by Nickel-Catalyzed Cross-Coupling of Furanosyl Acetates with Aryl Iodides.

Canonical nucleosides are vulnerable to enzymatic and chemical degradation, yet their stable mimics-C-aryl nucleosides-have demonstrated potential utility in medicinal chemistry, chemical biology, and synthetic biology, although current synthetic methods remain limited in terms of scope and selectivity. Herein, we report a cross-electrophile coupling to prepare C-aryl nucleoside analogues from readily available furanosyl acetates and aryl iodides. This nickel-catalyzed modular approach is characterized by mild reaction conditions, broad substrate scope, excellent ß-selectivity, and high functional-group compatibility. The exclusive chemoselectivity with respect to the aryl iodide enables efficient preparation of a variety of C-aryl halide furanosides suitable for various downstream transformations. The practicality of this transformation is demonstrated through the synthesis of a potent analogue of a naturally occurring NF-κB activator.

Efficacy of an iodoform-based filling material for pulpectomy of primary teeth: A 24-month non-inferiority randomized clinical trial.

AIM: The aim of this non-inferiority randomized clinical trial was to compare the efficacy of an iodoform-based paste (Guedes-Pinto -(GP)) as a filling material in pulpectomies of primary teeth, and a standard material composed by calcium hydroxide and iodoform (CaOH/Iodof paste; Vitapex® ). DESIGN: A total of 104 teeth from 61 children (3-8 years old) were randomly allocated to two groups according to filling materials. Children were followed up for 24 months. The primary endpoint was the treatment success rate evaluated through clinical and radiographic examinations at follow-up, and the secondary outcome was the analysis of the canal filling quality. Differences in the proportion of treatment success was calculated based on 95% confidence intervals (95% CI) and with the Miettinen and Nurminen method in the intention-to-treat population, considering a -20% of the non-inferiority limit. RESULTS: From 104 randomized teeth, 102 were followed up after 24 months (attrition rate of 1.9%). The success rate of teeth treated with the GP paste was 86.8% (95% CI: 69.9-94.9) and 78.4% (95% CI: 61.8-89.1) with the CaOH/Iodof paste. Consequently, a non-inferiority of the GP paste was observed when compared to the CaOH/Iodof paste (P < .001). CONCLUSION: The GP paste has a non-inferior success rate than the CaOH/Iodof paste used as filling material for pulpectomy in primary teeth.

Targeted knockout of the gene OsHOL1 removes methyl iodide emissions from rice plants.

Iodine deficiency represents a public health problem worldwide. To increase the amount of iodine in the diet, biofortification strategies of plants have been tried. They rely on the exogenous administration of iodine to increase its absorption and accumulation. However, iodine is not stable in plants and can be volatilized as methyl iodide through the action of specific methyltransferases encoded by the HARMLESS TO OZONE LAYER (HOL) genes. The release of methyl iodide in the atmosphere represents a threat for the environment due to its ozone depletion potential. Rice paddies are among the strongest producers of methyl iodide. Thus, the agronomic approach of iodine biofortification is not appropriate for this crop, leading to further increases of iodine emissions. In this work, we used the genome editing CRISPR/Cas9 technology to knockout the rice HOL genes and investigate their function. OsHOL1 resulted a major player in methyl iodide production, since its knockout abolished the process. Moreover, its overexpression reinforced it. Conversely, knockout of OsHOL2 did not produce effects. Our experiments helped elucidating the function of the rice HOL genes, providing tools to develop new rice varieties with reduced iodine emissions and thus more suitable for biofortification programs without further impacting on the environment.

Initial Observation of Factors Interfering with the Treatment of Alveolar Osteitis Using Hyaluronic Acid with Octenidine-A Series of Case Reports.

Alveolar osteitis (AO) is a common complication following the extraction of the teeth, particularly the lower third molars. It starts within a few days after the extraction and manifests mainly as pain in the extraction site. Several strategies of treatment are available in order to relieve pain and heal the extraction wound. Recently, a novel medical device combining hyaluronic acid (HA) and octenidine (OCT) was introduced for the treatment of AO. This series of case reports aims to summarize the initial clinical experiences with this new device and to highlight factors possibly interfering with this treatment. The medical documentation of five patients with similar initial situations treated for AO with HA + OCT device was analyzed in detail. Smoking and previous treatment with Alveogyl (Septodont, Saint-Maur-des-Fossés, France) were identified as factors interfering with the AO treatment with the HA + OCT device. In three patients without these risk factors, the treatment led to recovery within two or three days. The patient pretreated with Alveogyl and the smoker required six and seven applications of the HA + OCT device, respectively. According to these initial observations, it seems smoking and previous treatment with Alveogyl prolong the treatment of AO using the HA + OCT device that, in turn, shows a rapid effect if these risk factors are not present.

Ag-exchanged mesoporous chromium terephthalate with sulfonate for removing radioactive methyl iodide at extremely low concentrations in humid environments.

The development of efficient adsorbents to remove radioactive methyl iodide (CH3I) in humid environments is crucial for air purification after pollution by nuclear power plant waste. In this work, we successfully prepared a post-synthetic covalent modified MIL-101 with a sulfonate group followed by the ion-exchange of Ag (I), which is well characterized by diffuse reflectance FT-IR spectroscopy, X-ray photoelectron spectroscopy (XPS) and the hydrophobic index (HI). After modification of the MOFs, we applied functionalized MIL-101 obtained by either one-pot synthesis (MIL-101-SO3Ag) or a post-synthetic modification process (MIL-101-RSO3Ag, R = NH(CH2)3) to remove the CH3I at an extremely low concentration (0.31 ppm) in an environment with very high relative humidity (RH 95%). Enhanced hydrophobicity of the surface-modified MIL-101 was evaluated by examining the HI with the competitive adsorption of water and cyclohexane vapor, with a high surface area maintained, as confirmed by Ar physisorption. Interestingly, the post-synthetically modified MIL-101-RSO3Ag showed exceptional adsorption performance as determined by its decontamination factor (DF = 195,350) at 303 K and RH 95%. This performance was in comparison to Ag (I)-exchanged 13X zeolite and MIL-101-SO3Ag, which include much higher amounts of Ag. Furthermore, MIL-101-RSO3Ag retained ~94-100% of its fresh adsorbent performance during five cycle repetitions.

Vanadium removal by cationized sawdust produced through iodomethane quaternization of triethanolamine grafted raw material.

In this study, two-step surface modification of sawdust using triethanolamine (at 180 °C) and iodomethane (at 42 °C) was performed to produce a novel quaternized biosorbent, TEA-I-SD. The characterization studies revealed significant morphological changes in the sawdust and successful quaternization with a nitrogen content of 5.75%. The highest vanadium removal (96.2%) was achieved at pH 4 (dosage 1 g/L, initial vanadium concentration 19.1 mg/L). Equilibrium was achieved within 8 h of contact time and the adsorption kinetics were well fitted with the pseudo-second-order model. Both film diffusion and intra-particle diffusion contributed to the adsorption process, while the latter was the rate-limiting step. The maximum vanadium adsorption capacity of TEA-I-SD (35.0 mg/g, pH 4) was close to the theoretical value obtained from the Langmuir model. The best fit was achieved with the Redlich-Peterson model, exhibiting a monolayer adsorption phenomenon. Tests with real mine water containing 11 mg/L of vanadium also confirmed its high removal (91.3%, dosage 1 g/L) using TEA-I-SD at pH 4. The TEA-I-SD could be reused three times without significant capacity loss after regeneration, although the desorption efficiency was rather low (synthetic solution: 38.5-40.5% and mine water: 26.2-43.1%).

One year clinical success of pulpectomy in primary molars with iodoform-calcium hydroxide paste.

OBJECTIVES: In order to retain primary molars, eg with irreversible pulpitis or pulp necrosis, pulpectomy can be an alternative to extraction. However, reports on the success of pulpectomies in primary teeth vary widely in the literature. Thus, the objective of this study was not only to analyze the success rate of primary tooth pulpectomy 12 months posttreatment in the setting of a specialized clinic, but also to identify and analyze various factors that modify the outcome. METHOD AND MATERIALS: Between 2012 and 2018, a total of 76 dental records of the Department of Preventive and Pediatric Dentistry at the University of Greifswald fulfilled the inclusion criteria, resulting in a 1-year analysis of 62 primary molars with an idoform-calcium hydroxide paste as root canal filling material almost exclusively covered by a stainless steel crown as restoration. RESULTS: The pulpectomy treatment was successful after 1 year in 93.5%, with a significantly higher survival for mandibular primary molars (100.0% vs 83.3%; chi-square test P = .01). Apart from the very few cases in the mixed dentition, no other factors related to the patient (sex, caries level, general health conditions, distance to clinic), tooth (first or second primary molar, pulpal and periapical condition before treatment), or treatment (indication, academic qualification of the operator, number of visits) proved to be of significance for the treatment outcome due to the overall high success rate. CONCLUSION: Pulpectomies for pulpally involved or even necrotic primary molars followed by stainless steel crowns as restoration should be considered as a treatment option, especially in the mandible. (Quintessence Int 2021;52:528-537; doi: 10.3290/j.qi.b1244443).

Outcomes of Calcium Hydroxide with Iodoform Pulpectomies in Primary Teeth.

Purpose: To assess retrospectively the success rate of calcium hydroxide with iodoform as a filling material in pulpectomies of primary molars with irreversible pulpitis or pulp necrosis, and to evaluate factors that affect outcomes.
Methods: This study consisted of records of 73 patients with primary molars treated with pulpectomy with high quality radiographs. Treatment was considered successful clinically if the tooth was not extracted and radiographs showed a decrease or no change in preexisting pathologic radiolucent defects.
Results: Follow-up ranged from three to 39 months (median: 21.5 months). The success rate of teeth restored with a stainless steel crown (SSC) on the same appointment (88.9 percent) was higher than for teeth that received a temporary restoration (P =0.001). There was no statistically significant difference between the success rate and the extent of resorption of root canal filling material. Primary second molars had a higher success rate than first molars (P =0.018). No difference was found between the level of pulpectomy filling and treatment success (P =0.17).
Conclusion: Pulpectomies done with calcium hydroxide and iodoform had an overall success rate of 74 percent. If restored with an SSC, the success rate increased to 88.9 percent. Resorption of the paste did not affect the success rate.

Spatial distribution and biogeochemical cycling of methyl iodide in the Yellow Sea and the East China Sea during summer.

Methyl iodide (CH3I) released from ocean is an important carrier of iodine, which plays an important role in ozone depletion in the atmosphere. Depletion of ozone has increased the amount of ultraviolet radiation that reaches the earth's surface and recent global warming has caused oceanic acidification as well as dust events, but how these environmental changes will affect CH3I concentration in the ocean is unclear. In this study, the spatial distributions and sources of CH3I in the atmosphere, seawater, and sediment porewater were measured in the Yellow Sea (YS) and the East China Sea (ECS) between June and July 2018. Higher concentrations in the atmosphere, seawater, and sediment were found in the YS than in the ECS, and surface seawater emissions were discovered to be the major contributors of atmospheric CH3I concentrations. Anthropogenic pollutants could explain significant spatial variation in the distribution of CH3I. High concentrations of CH3I in sediment porewater increased diffusion into bottom waters, with diffusive fluxes of 0.2-6.5 nmol m-2 d-1. Preliminary results during the in situ seawater incubation experiments showed that the photochemical production rate of CH3I ranged from 0.008 to 0.214 pmol L-1 h-1 under ultraviolet light, and an enhancement emission of CH3I from phytoplankton occurred with the addition of dust, while a reduction of CH3I appeared under lower pH conditions.

Inability of GSTT1 to activate iodinated halomethanes to mutagens in Salmonella.

Drinking water disinfection by-products (DBPs), including the ubiquitous trihalomethanes (THMs), are formed during the treatment of water with disinfectants (e.g., chlorine, chloramines) to produce and distribute potable water. Brominated THMs (Br-THMs) are activated to mutagens via glutathione S-transferase theta 1 (GSTT1); however, iodinated THMs (I-THMs) have never been evaluated for activation by GSTT1. Among the I-THMs, only triiodomethane (iodoform) has been tested previously for mutagenicity in Salmonella and was positive (in the absence of GSTT1) in three strains (TA98, TA100, and BA13), all of which have error-prone DNA repair (pKM101). We evaluated five I-THMs (chlorodiiodomethane, dichloroiodomethane, dibromoiodomethane, bromochloroiodomethane, and triiodomethane) for mutagenicity in Salmonella strain RSJ100, which expresses GSTT1, and its homologue TPT100, which does not; neither strain has pKM101. We also evaluated chlorodiiodo-, dichloroiodo-, and dibromoiodo-methanes in strain TA100 +/- rat liver S9 mix; TA100 has pKM101. None was mutagenic in any of the strains. The I-THMs were generally more cytotoxic than their brominated and chlorinated analogues but less cytotoxic than analogous trihalonitromethanes tested previously. All five I-THMs showed similar thresholds for cytotoxicity at ~2.5 µmoles/plate, possibly due to release of iodine, a well-known antimicrobial. Although none of these I-THMs was activated by GSTT1, iodoform appears to be the only I-THM that is mutagenic in Salmonella, only in strains deficient in nucleotide excision repair (uvrB) and having pKM101. Given that only iodoform is mutagenic among the I-THMs and is generally present at low concentrations in drinking water, the I-THMs likely play little role in the mutagenicity of drinking water.