Synthesis of 6-alkoxy and 6-hydroxy-alkyl amine derivatives of braylin as vasorelaxing agents.

Braylin (10b) is a 8,8-dimethyl chromenocoumarin present in the plants of the family Rutaceae and Meliaceae and possesses vasorelaxing and anti-inflammatory activities. In this study, six 6-alkoxy (10b, 15-19), and twelve 6-hydroxy-alkyl amine (20a-20l) derivatives of braylin (11 and 12) were synthesized to delineate its structural requirement for vasorelaxing activity. The synthesized compounds were evaluated for vasorelaxation response in preconstricted intact rat Main Mesenteric Artery (MMA). The compounds showed l-type VDCC channel blockade depended and endothelium-independent vasorelaxation within the range of Emax < 50.00-96.70 % at 30 µM. Amongst all, 6-alkoxy derivatives were more active than 6-hydroxy-alkyl amine derivatives. The structural refinements about braylin showed that deletion of its methoxy group or homologation beyond ethoxy group presented deleterious effect on vasorelaxation response of braylin. Interestingly, substituting the ethoxy group in 10b presented the best activity and selectivity towards l-type VDCC channel blockade, a specific target cardiovascular function.

Synthesis of amide derivatives of 3-aryl-3H-benzopyrans as osteogenic agent concomitant with anticancer activity.

The present study reports a series of 3-aryl-3H-benzopyran-based amide derivatives as osteogenic agents concomitant with anticancer activity. Six target compounds viz 22e, 22f, 23i, and 24b-d showed good osteogenic activity at 1 pM and 100 pM concentrations. One of the potential molecules, 24b, effectively induced ALP activity and mRNA expression of osteogenic marker genes at 1 pM and bone mineralization at 100 pM concentrations. These molecules also presented significant growth inhibition of osteosarcoma (MG63) and estrogen-dependent and -independent (MCF-7 and MDA-MB-231) breast cancer cells. The most active compound, 24b, inhibited the growth of all the cancer cells within the IC50 10.45-12.66 µM. The mechanistic studies about 24b showed that 24b induced apoptosis via activation of the Caspase-3 enzyme and inhibited cancer cell migration. In silico molecular docking performed for 24b revealed its interaction with estrogen receptor-ß (ER-ß) preferentially.

Lupus Erythematosus Tumidus Associated With Hemophagocytosis.

ABSTRACT: A case of lupus erythematosus tumidus (LET), a subtype of chronic cutaneous lupus erythematosus, in an 85-year-old woman who presented with discrete indurated erythematous plaques over the face and upper chest is described. A skin biopsy showed features in keeping with a diagnosis of LET. Unusually however, the lymphocytic infiltrate contained frequent macrophages that demonstrated hemophagocytosis. Most of the phagocytosed cells were lymphocytes, but there was also evidence of erythrophagocytosis. The presence of conspicuous hemophagocytosis has only rarely been reported in skin biopsies of patients with autoimmune conditions. These include systemic lupus, neonatal lupus and dermatomyositis, and on 2 occasions in cases of nonspecified cutaneous lupus erythematosus. To the best of our knowledge, hemophagocytosis as a feature of LET has not been previously described in the literature.

Occupational Localized Cutaneous Argyria With Pseudo-Ochronosis in a Jeweler.

ABSTRACT: A case of localized argyria in a 36-year-old female jeweler is described who presented with 2 discrete and asymptomatic bluish-black pigmented macules on the pulp of her left middle finger. A skin biopsy from both lesions demonstrated deposition of brown/black pigmented granules along the basement membrane zone of eccrine glands, blood vessels, nerves, and the dermo-epidermal junction fully in keeping with silver deposition. In addition, there was yellow-brown deposition seen within the interstitial dermis mimicking an early form of ochronosis, so called "pseudo-ochronosis." This latter feature is rarely described in cases of argyria. Transmission electron microscopy and energy dispersive x-ray spectroscopy confirmed the presence of electron dense particles up to 150 nm in diameter and the presence of silver, respectively. On further questioning, the patient had a history of localized and chronic exposure to silver, which specifically involved holding and manipulating silver wires and rings over the left middle finger. This case highlights an unusual and rare presentation of localized argyria in a jeweler. In addition, our case showed preferential silver deposition on dermal elastic fibers which has not been previously described in the literature.

Synthesis and evaluation of substituted 8,8-dimethyl-8H-pyrano[2,3-f]chromen-2-one derivatives as vasorelaxing agents.

A series of substituted 8,8-dimethyl-8H-pyrano[2,3-f]chromen-2-ones (chromeno-coumarin hybrids) was synthesized from scopoletin (11) as vasorelaxing agents. The synthesized compounds 21a-f, 22, 23a-e and scopoletin (11) were evaluated for vasorelaxation in endothelium intact rat main mesenteric artery (MMA). Compounds 11, 21a, 21c-f and 22 showed significant vasorelaxation in precontracted MMA within the range of EC50 value 1.58-5.02 µM. These derivatives presented 29.40-70.89 fold increased sensitivity for experimental tissue compared to scopoletin (11), the parent molecule. Among others, 22 was found to be the most active compound which had EC50 1.58 µM with 70.89 fold increased sensitivity. The mechanistic evaluation of 22 showed that it exerted vasorelaxation through Ca2+-activated K+ (BKca) channel and the effect was endothelium-independent.

Synthesis of Polycyclic Ether-Benzopyrans and In Vitro Inhibitory Activity against Leishmania tarentolae.

Construction of a focused library of polycyclic ether-benzopyrans was undertaken in order to discover new therapeutic compounds that affect Leishmania growth and infectivity. This is especially of interest since there are few drug therapies for leishmaniasis that do not have serious drawbacks such high cost, side effects, and emerging drug resistance. The construction of these polycyclic ether-benzopyrans utilized an acetoxypyranone-alkene [5+2] cycloaddition and the Suzuki-Miyaura cross-coupling. The multi-gram quantity of the requisite aryl bromide was obtained followed by effective Pd-catalyzed coupling with boronic acid derivatives. Compounds were tested in vitro using the parasitic protozoan, Leishmania tarentolae. Effects of concentration, time, and exposure to light were evaluated. In addition, the effects on secreted acid phosphatase activity and nitric oxide production were investigated, since both have been implicated in parasite infectivity. The data presented herein are indicative of disruption of the Leishmania tarentolae and thus provide impetus for the development and testing of a more extensive library.

Effect of ethanolic extract of Quisqualis indica L. flower on experimental esophagitis in albino Wistar rats.

Quisqualis indica L., Syn. Combretum indicum (L.) DeFilipps., known as Rangoon creeper or Chinese Honeysuckle, is an abundant source of phenols and flavonoids thathave crucial role in free radical scavenging. Therefore, here we investigated whether extract of Q. indica flower has any role against esophagitis through scavenging of free radical oxygen species. In this study, we elucidated the effect of ethanolic flower extract of Q. indica on experimental esophagitis in albino Wister rats. The fasted animals divided into six groups and received carboxymethyl cellulose (CMC) (0.25%, 3 mL/kg, Sham control) or toxic control or pantoprazole (30 mg/kg) or flower extract of different doses (100, 200 and 300 mg/kg) were subjected to pylorus and fore stomach ligation. All the animals were sacrificed after 8 h and evaluated for various parameters such as total acidity, free acidity, gastric pH, volume of gastric juices and esophagitis index. Esophageal tissues were subjected to estimation of various oxidative stress parameters like malonaldehyde (MDA), glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and protein carbonyl (PC). In a separate experiment, in vitro antioxidant assays such as DPPH and H2O2 assays, total phenolic and flavonoid contents were also conducted. The results revealed that treatments with pantoprazole and flower extracts significantly inhibited the gastric secretion, total acidity and esophagitis index. Various oxidative stress parameters also restored to normal level in the treated groups. This action could be due to the presence of higher phenolic and flavonoid contents. All these findings collectively suggest that the flower extract of Q. indica possibly possess anti-esophagitis potential.

Outcome Of Distally Based Sural Artery Flap For Distal Third Of Leg And Foot Defects.

BACKGROUND: Due to precarious blood supply, skin coverage for defects of leg, heel, dorsum of foot and the ankle has been a complicated task for plastic surgeons & orthopaedic surgeons. The present study aimed to prospectively evaluate the outcome of distally based sural flap for coverage of defects distal third of leg, ankle & foot. METHODS: In this study 15 patients with soft tissue defects on distal third of leg in (n=2), heel (n=4), medial malleolus (n=3), lateral malleolus (n=1), Achillis tendon (n=2), anterior ankle (n=2) and in dorsum of foot (n=1) were operated for coverage of defect by distally based sural flap. All the cases were done as secondary procedures. RESULTS: All the flaps showed good results except five minor complications. Three flaps showed superficial skin necrosis and two showed partial tip necrosis. CONCLUSIONS: Distally based sural artery flap is very useful in covering the defects of lower leg, heel and dorsum of foot. It is reliable, easy to raise with minimal morbidity to the patient. This flap does not sacrifice any of the major vessels of the limb and hence it is very safe flap.

Synthesis of 3,5-dihydroxy-7,8-dimethoxy-2-(4-methoxyphenyl)benzopyran-4-one derivatives as anticancer agents.

Different alkyl amide (15a-l) and alkyl amine (16a-e) derivatives of 7,8-dimethoxy-3-hydroxy-2-(4-methoxyphenyl)benzopyran-4-one were synthesized and evaluated for their anticancer activity against five different cancer cell lines using SRB assay. Compounds 15e, 15i, 15j and 16a-e showed significant anticancer activity within the range of IC50 2.58-34.86µM. The most promising molecule, 16c, was further analyzed for its effect on cell cycle and apoptosis of estrogen receptor positive cancer cells (MCF-7 cells) which showed that 16c triggered apoptosis in MCF-7 cells and arrested cells population at sub-G0 (apoptotic) and G2M phase. In tubulin polymerization assay, 16c interfered with kinetics of tubulin polymerization.

Cytotoxicity of alkaloids isolated from Argemone mexicana on SW480 human colon cancer cell line.

CONTEXT: Argemone mexicana Linn. (Papaveraceae) has been used as traditional medicine in India and Taiwan for the treatment of skin diseases, inflammations, bilious, fever, etc. Some alkaloids of A. mexicana have been screened for their cytotoxicity on different cancer cell lines. OBJECTIVE: The study investigates potential cytotoxic effects of alkaloids isolated from aerial part of A. mexicana on SW480 human colon cancer cell line. MATERIALS AND METHODS: Six alkaloids, 13-oxoprotopine, protomexicine, 8-methoxydihydrosanguinarine, dehydrocorydalmine, jatrorrhizine, and 8-oxyberberine were isolated from the methanol extract of A. mexicana. Cytotoxicity of these alkaloids was studied on SW480 human colon cancer cell line at 1, 25, 50, 75, 100, 125, 150, and 200 µg/mL for 24 and 48 h. Cells were seeded in a 96-well micro-plate at a concentration of 2 × 10(4) cells per well and MTS assay was performed to assess cytotoxicity in terms of cell viability. RESULTS: At 200 µg/mL, protomexicine and 13-oxoprotopine showed mild cytotoxicity (∼24-28%) whereas dehydrocorydalmine exhibited moderate cytotoxicity (∼48%). 8-Oxyberberine was mildly cytotoxic (∼27%) at 24 h but was more potent (∼76%) at 48 h. Jatrorrhizine and 8-methoxydihydrosanguinarine were most potent (∼95-100%) in inhibiting the human colon cancer cell proliferation showing complete reduction in cell viability. DISCUSSION AND CONCLUSION: This is the first study on the effect of these alkaloids on SW480 human colon cancer cell line. This study indicates that some alkaloids of A. mexicana strongly inhibit the cell proliferation in human colon cancer cells, and it might be a basis for future development of a potent chemotherapeutic drug.

Next-Generation Sequencing (NGS): Platforms and Applications.

The demand for accurate, faster, and inexpensive sequencing of deoxyribonucleic acid (DNA) is increasing and is driving the emergence of next-generation sequencing (NGS) technologies. NGS can provide useful insights to help researchers and clinicians to develop the right treatment options. NGS has wide applications in novel fields in biology and medicine. These technologies are of great aid to decode mysteries of life, to improve the quality of crops to detect the pathogens, and also useful in improving life qualities. Thousands to millions of molecules can be sequenced simultaneously in parallel using various NGS methods. NGS can identify and characterize the microbial species more comprehensively than culture-based methods. Recently, the NGS approach has been used for oral microbial analysis.

Efficacy of Infraclavicular Brachial Plexus Block Alone Versus Combination With Suprascapular Nerve Block in Patients Undergoing Shoulder Surgeries: A Single-Blind, Randomized Trial.

Background and aim The regional anesthesia technique is commonly used for upper extremity surgery as an alternative to general anesthesia. The study aimed to compare the efficacy of infraclavicular brachial plexus block (BPB) and a combination of infraclavicular brachial plexus block with suprascapular nerve block for postoperative analgesia in patients undergoing shoulder surgeries. Method A total of 62 patients of both sexes with the American Society of Anaesthesiologists (ASA) physical status I/II/III, aged between 18 and 65 years, and undergoing shoulder surgery, were included in this prospective, single-blinded, randomized controlled trial. Patients were equally allocated into two groups: 31 in group A and 31 in group B. After pre-anesthetic evaluation, the purpose and protocol of the study were explained to patients, and informed consent was obtained. Thirty-one patients in group A were given infraclavicular brachial plexus block using 30 ml 0.375% bupivacaine while 31 patients in group B were given a combination of infraclavicular brachial plexus block using 30 ml 0.375% bupivacaine and suprascapular nerve block using 5 ml 0.375% bupivacaine. Blocks were given using ultrasound guidance and a peripheral nerve stimulator; the suprascapular block was given in the sitting position while the infraclavicular block was provided in the supine position. General anesthesia was administered in the operation theatre in the supine position after the administration of blocks. The pain was assessed using the visual analog scale (VAS) and the satisfaction score was assessed by the numeric rating scale (NRS). The Mann-Whitney U test was applied for comparison of pain between the two groups. The chi-square test was utilized for comparing the categorical variables. Result The postoperative pain was significantly lower (p<0.001) in group B as compared to group A at all the periods of observation, i.e., 0h (2.77±0.72 vs. 5.42±0.77), 6h (3.89±0.70 vs. 5.94±0.73), 12h (5.66±0.93 vs. 6.58±0.88), and 24h (6.16±0.80 vs. 6.74±0.90). These findings illustrate that group B patients who received a combination of infraclavicular brachial plexus block and suprascapular nerve block for shoulder surgeries had better pain relief than group A patients who received only the infraclavicular approach. The mean NRS score of patient satisfaction in group B (7.26±0.58) was significantly higher (p<0.001) in comparison to group A (6.16±0.64). Diaphragmatic palsy was observed in only one case in group A and none in group B. No other complication was observed in any of the patients during the study period. Conclusion The combination of infraclavicular brachial plexus block and suprascapular nerve block displays a positive postoperative analgesic profile with less usage of rescue analgesic doses and better patient satisfaction after shoulder surgery.

To Determine the Quality of Life in Indian Women After Peripartum Hysterectomy Using a Hindi Version of the SF-36 Questionnaire.

Objective: The objective of the study was to determine the quality of life in women after peripartum hysterectomy using a Hindi version of the SF-36 questionnaire. Background: There are long-term effects on quality of life in women after peripartum hysterectomy. The effects on physical, mental, and social functioning have a prolonged recovery. No studies have been done in Indian women after peripartum hysterectomy to evaluate quality of life. Methods: Patients who underwent peripartum hysterectomy from January 2017 to May 2021 were contacted to participate in the study. To determine the quality of life post-surgery, a Hindi version of the 36-item Short-Form Health Survey (SF-36) was used for a face-to-face personal interview-based assessment. The participants were divided into two groups based on the duration between surgery and the interview. The aggregate scores for the eight components of SF-36 were calculated, and responses were analyzed. Results: Out of the 138 post-hysterectomy women, 118 were enrolled in the study. Women who could not be contacted [14 (10.14%)] and those who died post-procedure [6 (4.35%)] were excluded. Out of the total, 43 assessed participants were within 2 years of surgery, and 75 were after 2 years of surgery. The group that was assessed after 2 years of surgery had a significantly lower quality of life in six, out of the eight aspects of SF-36 domains. Conclusion: Women after peripartum hysterectomy undergo a prolonged recovery phase with effects on physical, mental, and social functioning. A multi-disciplinary long-term follow-up including physiotherapy and psychotherapy is required and that should be guided by a dedicated clinical team.

An in vivo evaluation of different methods of working length determination.

OBJECTIVE: The purpose of this in vivo study was to compare the ability of digital tactile, digital radiographic and electronic methods to determine reliability in locating the apical constriction. MATERIALS AND METHODS: Informed consent was obtained from patients scheduled for orthodontic extraction. The teeth were anesthetized, isolated and accessed. The canals were negotiated, pulp chamber and canals were irrigated and pulp was extirpated. The working length was then evaluated for each canal by digital tactile sensation, an electronic apex locator (The Root ZX) and digital radiography. The readings were then compared with post-extraction working length measurements. RESULTS: The percentage accuracy indicated that EAL method (Root ZX) shows maximum accuracy, i.e. 99.85% and digital tactile and digital radiographic method (DDR) showed 98.20 and 97.90% accuracy respectively. CLINICAL SIGNIFICANCE: Hence, it can be concluded that the EAL method (Root ZX) produced most reliable results for determining the accurate working length.

Congenital anterior urethral valves and diverticula.

AIMS OF STUDY: Anterior urethral valves (AUVs) are rare congenital anomalies causing lower urinary tract obstruction in children. The present study highlights the clinical approach in identifying the condition and its treatment options. METHOD: Single centre, retrospective study of children. RESULT: Over a 16 year duration, 14 children were diagnosed with AUVs and diverticula with a mean age of 15 months. Clinical features included straining at micturation and a palpable penile swelling. Diagnosis was confirmed with voiding cystourethrogram and cystoscopy. An open surgical procedure was performed in 12 cases and endoscopic intervention done in one. On follow up 13 patients showed restoration of a normal voiding stream and normal renal function. One child died of chronic renal failure due to a delayed presentation, severe back-pressure changes, urinary ascites, and urosepsis. One patient developed a small urethrocutaneous fistula that healed spontaneously. CONCLUSION: AUV, though rare, should be recognizable due to the combination of a poor urinary stream and visible swelling in the ventral aspect of penis. Open surgical excision is the method of choice, and the outcome is excellent. LEVEL OF EVIDENCE: Level IV.

Effect of Erector Spinae Block and Pectoralis Block on Quality of Recovery and Analgesia After Modified Radical Mastectomy: A randomised controlled study.

Objectives: Post-operative pain after a modified radical mastectomy ranges from moderate to severe. Pectoralis (PECS) block has been found to be more effective than erector spinae block in reducing pain and the consumption of rescue analgesia in the post-operative period. This study aimed to compare the effect of erector spinae block and PECS block on the quality of recovery after modified radical mastectomy using the quality of recovery (QoR-40) score. Methods: This randomised controlled study was conducted at King George's Medical University, Lucknow, India, from 9th October 2020 to 9th October 2021. After general anaesthesia, patients were given blocks according to computer-generated randomisation: Group I: PEC I and PEC II (PECS) blocks; Group II: erector spinae plane (ESP) block; and Group III: control group (no intervention). The QoR-40 score was observed on the morning of the surgery and after 24 hours. Time to rescue analgesia and the total consumption of rescue analgesia in the first 24 hours were also observed. Results: A total of 90 patients were included (30 in each group). In the post-operative period after 24 hours, global QoR-40 scores were 183.64 ± 6.36, 179.68 ± 6.38 and 171.37 ± 6.88 in the PECS, ESP and control groups (P <0.0001). But there was no statistically significant difference between the QoR scores of PECS and ESP group patients (P = 0.0551). The total requirement of rescue analgesic was significantly lower in the PECS group (137.28 ± 31.46 mg) than in the ESP (189.46 ± 42.98 mg) and control (229.57 ± 46.80 mg) groups (P <0.0001). Time to first rescue analgesia was significantly higher in the PECS group (6.53 ± 2.78 hours) than in the ESP (4.05 ± 2.91 hours) and control (2.15 ± 1.51 hours) groups (P <0.0001). Conclusion: Both ESP and PECS blocks were effective in improving the QoR score and in reducing the consumption of rescue analgesia after modified radical mastectomy.

Short-Term Adverse Drug Reactions to Antiretroviral Therapy in Children with HIV: A Cohort Study.

OBJECTIVES: To carry out an active surveillance for adverse drug reactions (ADRs) in children with HIV infection newly initiated on antiretroviral therapy (ART), determine risk factors for their occurrence, and assess their influence on adherence to ART. METHODS: All children newly initiated on ART from 1st March 2014 to 30th June 2019 at a tertiary care children's hospital in New Delhi, were actively monitored for ADRs to ART for a period of 6 mo after ART initiation. The frequency, spectrum, and severity of ADRs, their influence on adherence, and risk factors for their occurrence were analyzed. RESULTS: Among the 174 enrolled children, ADRs were observed in 78 (44.8%) children during the first 6 mo after ART initiation. Total numbers of episodes of ADR observed were 108 (0.62 episodes of ADR/child). Sixty percent of events were of grade 1 severity, 19.4% events were of grade 2 and 3 each, while 1 (0.9%) event was of grade 4 severity. Adherence to ART was adversely affected in 21.8% of ADRs. Gastrointestinal symptoms (49.1%) were most frequent among all the events observed. Zidovudine, lopinavir/ritonavir, efavirenz and nevirapine based regimes were significantly associated with hematological, gastrointestinal, neurological, and dermatological ADRs, respectively. Children with immunological suppression were at a higher risk of developing ADRs as compared to those without it [RR 1.9 (95% CI (1.1-3.2)]. CONCLUSIONS: ADRs to ART are very frequent; most of them are mild and self-limiting. However, they can adversely impact adherence to ART. Anticipatory guidance, ongoing monitoring, and provision of symptomatic treatment will help tide over most ADRs and reduce their adverse impact upon ART adherence.

Comparison of single and multiple file rotary endodontic instruments for debris and irrigant extrusion: An in vitro study.

Aim: The aim of this study was to assess and compare the quantity of apically debris which was extruded apically by TruNatomy (TN), ProTaper Next (PTN), HyFlex electric discharge machining (EDM), and HyFlex controlled memory (CM), following root canal preparation. Materials and Methods: Sixty extracted single-canal mandibular premolars were used. The root canal preparation was done with TN, HyFlex EDM, PTN, or HyFlex CM files. The preweight debris, which was extruded apically, was collected in the Eppendorf tube and later on incubated at 670°C for 3 days and weighed again to record the extruded debris. Results: The result showed that there was a significant reduction in debris extrusion by TN system, followed by PTN system, HyFlex EDM, and maximum extrusion in HyFlex CM (P < 0.05). Between the PTN and TN groups as well as between the HyFlex EDM and HyFlex CM groups, statistically significant difference was not observed (P > 0.05). Conclusion: Apical debris extrusion is the inherent nature of the all file systems. Nevertheless, the TN file system produced substantially minimum debris extrusion among other systems compared in the study.

Evaluating the Efficacy of Certain Intermediate Irrigants in Preventing Precipitate Formed Due to Sodium Hypochlorite and Chlorhexidine Within the Root Canal System: An In Vitro Study.

AIM: Root canal irrigation using a mixture of sodium hypochlorite (NaOCL) and chlorhexidine gluconate (CHX) might cause a precipitate to develop. This study aims to check the efficacy of sodium thiosulfate and normal saline as irrigating solutions. MATERIALS AND METHODS: Roots of 45 teeth were biomechanically prepared, and the teeth were then tested. A size 15k file was introduced to the point where the apical foramen could be visible in order to provide an accurate reading of the working length. As a precaution against irrigating solutions leaking out, the specimens' tips were sealed with modeling wax before being instrumented. Each group's root canals were instrumented with #F4 hand Protaper (Dentsply Sirona, USA) as recommended by the manufacturer. Between instrumentation, The canals were lubricated with ethylenediamine tetraacetic acid (EDTA) and irrigated with 2.5% sodium hypochlorite (RC Help, Prime Dental, Mumbai, India). Fifteen samples were randomly assigned to one of three experimental categories based on the middle watering arrangement used: Group 1 (control), Group 2 (saline irrigant), and Group 3 (3.86% sodium thiosulfate). The jewel plate was submerged in water to cool it down, while two longitudinal scores were made on the root's buccal and lingual surfaces. We used a stereomicroscope to examine the exposed surfaces of the root trench in the coronal, middle, and apical thirds for the orange-earthy colored material (Stereozoom Nikon magnifying lens under 20X amplification), and we used the Mann-Whitney U test and the Kruskal Wallis test during our thorough analysis. RESULTS: The precipitation generated in the coronal, middle, and apical thirds had significantly different thicknesses. While precipitation did occur in all three regions, it was at a much lower rate in the apical third compared to the coronal and middle regions. In Group 1, the control group, the precipitate was thicker than in Groups 2 (saline irrigant) and 3 (3.86% sodium thiosulfate). CONCLUSION: Sodium thiosulfate, which is a biocompatible solution, can be used as an intermediate irrigant as it shows less precipitate as compared to saline.

Effect of remineralizing agent on laser and nonlaser bleached enamel surfaces subjected to erosion: An in vitro study.

Aim: Assessment of remineralizing agent's effect on laser and nonlaser bleached enamel surfaces subjected to erosion. Materials and Methods: In this study, 80 extracted human permanent anteriors were collected and divided into 4 groups with 20 teeth per sample. Enamel specimen of 3 mm × 3 mm were made using polyvinyl chloride rings and acrylic and randomly divided into four groups. Then the specimens were subjected to initial microhardness test using Vicker's hardness tester (AVK-CO, Mitutoyo, Japan). Two indentations were placed at 100 mm from one another in the center of all the samples. Bleaching with laser and without laser using hydrogen peroxide was performed followed by remineralization in the groups (Groups 1a and 2a) and then were subjected to erosion. The final hardness was measured using the above method used for initial microhardness. Results: Microhardness in the remineralized groups showed least variation. The group in which laser bleaching was performed along with remineralization as compared with nonlaser bleaching group with remineralization showed improvement in microhardness but the data was not statistically significant. A significant difference was noted between the laser and remineralization group when compared with the groups in which no remineralization was done. Conclusion: After bleaching the enamel surface is more prone to erosion, so to improve the microhardness of bleached enamel a remineralizing agent should be used. A combination of diode laser bleaching and remineralizing agents leads to improved microhardness of the bleached enamel thus proving this combination to be efficacious.