Barriers in Rubber Dam Isolation Behaviour of Dental Students During Adhesive Restorative Treatments: A Cross-Sectional Study.

PURPOSE:  There are unfavorable opinions connected with rubber dam isolation amongst dental students during adhesive restorative treatments. The aim of this study was to investigate the various barriers to practicing rubber dam isolation during dental procedures and provide necessary insight towards implementation of rubber dam among undergraduate dental students in Jazan. MATERIALS AND METHODS:  A pre-validated questionnaire in English entitled Rubber Dam Isolation Survey (E-RDIS) based on the Capability Opportunity Motivation-Behaviour (COM-B) model of behavioral change wheel was responded by 226 university dental students. RESULTS:  The satisfaction of training was highest among sixth year students (Mean=3.57, p<0.001). Fourth year dental students scored higher in the capability (Mean=3.18) and were more highly motivated to use rubber dams (Mean=4.21). Third year students were more likely to use rubber dams in anterior teeth (Mean=3.52) whereas fourth year students use rubber dam in posterior teeth (Mean=3.74). Lack of motivation was found to be the significant barrier influencing rubber dam usage (odds ratio (OR)=12.1; 3.74, p<0.05). CONCLUSION:  The satisfaction with training differed among the students of different years. The rubber dam technique might be used more frequently if it were made clear to students that mastering it would be necessary for them to receive good grades.

Evaluating the Efficacy of Platelet-Rich Fibrin Matrix versus Subepithelial Connective Tissue Grafts in Dental Root Coverage: A Comparative Study Using Modified Ruben's Technique.

BACKGROUND Dental root coverage, crucial in managing gingival recessions, traditionally utilizes subepithelial connective tissue grafts. However, this approach has limitations such as donor site morbidity and graft availability. Recent studies have introduced platelet-rich fibrin (PRF) as an alternative, leveraging its regenerative potential and growth factors. Despite the promise, comparative assessments between PRF and conventional grafts remain limited. This research probes whether PRF, when used beneath a modified Ruben's mixed flap, could provide comparable or superior dental root coverage than a subepithelial connective tissue graft. MATERIAL AND METHODS We enrolled 30 patients exhibiting Miller's class I and II recession in this comparative case series. Patients were randomly assigned to receive either a connective tissue graft (15 patients) or a PRF matrix (15 patients), both covered by a modified Ruben's mixed flap. RESULTS Clinical parameters, including full mouth plaque scores, bleeding scores, probing sulcus depth, clinical attachment level, gingival position assessment, width, and thickness of attached gingiva, were assessed in both the control and test groups at baseline, 6 months, and 12 months post-surgery. Significant differences were observed at all intervals.At the 12-month mark, the control group (connective tissue graft) achieved 91% complete root coverage, while the test group (PRF matrix) achieved 86%. However, this difference was not statistically significant. CONCLUSIONS The study outcomes suggest comparable gains in root coverage and attached gingiva between the connective tissue graft and PRF matrix groups. Thus, the results support our hypothesis that a subepithelial PRF matrix can serve as a viable alternative to a subepithelial connective tissue graft for treating dental root coverage.

Nanohydroxyapatite in dentistry: A comprehensive review.

Enamel, being the hardest and the highest mineralized tissue of the human body, contains nearly 96% inorganic components and 4% organic compounds and water. Dentin contains 65% inorganic components and 35% organic and water content. The translucency and white appearance of enamel are attributed to Hydroxyapatite (HA), which constitutes the major part of the inorganic component of dental hard tissue. With the advent of nanotechnology, the application of Nanohydroxyapatite (nHA) has piqued interest in dentistry due to its excellent mechanical, physical, and chemical properties. Compared to HA, nHA is found to have superior properties such as increased solubility, high surface energy and better biocompatibility. This is due to the morphological and structural similarity of nanosized hydroxyapatite particles to tooth hydroxyapatite crystals. These nanoparticles have been incorporated into various dental formulations for different applications to ensure comprehensive oral healthcare. To prevent dental caries, several nHA based dentifrices, mouth rinsing solutions and remineralizing pastes have been developed. nHA-based materials, such as nanocomposites, nano impression materials, and nanoceramics, have proven to be very effective in restoring tooth deformities (decay, fracture, and tooth loss). The nHA coating on the surface of the dental implant helps it bind to the bone by forming a biomimetic coating. A recent innovative strategy involves using nHA to reduce dentinal hypersensitivity and to reconstruct periodontal bone defects. The purpose of the present review is to discuss the different applications of nHA in dentistry, especially in preventive and restorative dentistry, dental implantology, bleaching and dentine hypersensitivity management.

Challenges Assessment in Endodontics Among Undergraduate Students.

Objective To explore perceptions of undergraduate dental students regarding difficulties faced during endodontic procedures. Methods An e-questionnaire was sent to 57 fourth-year and 45 fifth-year dental students. It comprised questions regarding demographic data and difficulties faced during different steps of the endodontic treatment. The responses were recorded on a 5-point Likert scale. During dichotomization, responses where one and two were chosen were considered yes whereas responses where three, four, and five were chosen were considered no. The sample size (SS) calculated using the Qualtrics SS calculator was 89. Data were analyzed using SPSS version 20. Frequencies and percentages were calculated. A p-value of less than 0.05 was considered significant. The chi-square test was applied for comparison based on the students' academic year and genders. Results Ninety students responded with an 88.2% response rate. Most students reported not facing any difficulty in differentiating healthy pulp and periapex from conditions of pulp pathosis (78.9%) and periapical pathosis (75.6%). Most males found access opening and de-roofing of the pulp chamber (35.6%) and working length determination (31.1%) difficult. Females reported having difficulty mostly in mesial and distal shift radiograph techniques (55.6%) and access openings (51.1%). No statistical difference was found based on an academic year or gender except in the use of mesial and distal shift techniques for radiograph acquisition Conclusion Assessing difficulties encountered by students during endodontic therapy can aid in the development of teaching strategies for preclinical and clinical instruction. Mesial and distal shift techniques, access cavity preparation, and working length determination are areas requiring more focus in the training process.

Impact Strength of Various Types of Acrylic Resin: An In Vitro Study.

AIM: The aim of this study is to evaluate and compare the impact strength of conventional acrylic resin, high-impact acrylic resin, high-impact acrylic resin reinforced with silver nanoparticles, and high-impact acrylic resin reinforced with a zirconium oxide powder. MATERIALS AND METHODS: A total of 60 samples were prepared of dimensions 60 mm length × 7 mm width × 4 mm thickness to test impact strength. Machined stainless steel dies of the same dimension were used to form molds for the fabrication of these samples. Of 60 samples, 15 samples were prepared each from conventional acrylic resin (Group A1), high-impact acrylic resin (Group A2), acrylic resin reinforced with silver nanoparticles (Group A3), and acrylic resin reinforced with zirconium oxide powder (Group A4). Izod-Charpy pendulum impact testing machine was used. RESULTS: The impact strength of group A1 was in the range of 2.83-3.30 kJ/m2 (M = 3.12 kJ/m2, SD = 0.16), group A2 was in range of 5.10-5.78 kJ/m2 (M = 5.51 kJ/m2, SD = 0.18), group A3 was in range 3.18-3.56 kJ/m2 (M = 3.37 kJ/m2, SD = 0.11), and group A4 was in range 7.18-7.78 kJ/m2 (M = 7.5 kJ/m2, SD = 0.18). Statistical analysis using one-way ANOVA and t-test revealed significant differences (p < 0.001). CONCLUSION: High-impact acrylic resin reinforced with zirconium oxide powder has the highest impact strength. CLINICAL SIGNIFICANCE: This research sheds light on the usefulness of novel filler materials in clinical prosthodontics.

Red-Complex Bacterial Levels in Pregnant Women With Preeclampsia and Chronic Periodontitis.

OBJECTIVES: The presence of red-complex bacteria (RCB) has been associated with the occurrence of not only periodontal disease but also other systemic diseases, thereby potentiating an oral-systemic relationship. This study aimed to explore the levels of periodontal RCB in pregnant preeclamptic women with periodontal disease, potentiating the pathophysiology of a bacterial association in both periodontitis and preeclampsia. METHODS: Six hundred pregnant women (aged 20 to 35 years) in their third trimester were selected and divided into 3 groups comprising a control group (systemically and periodontally healthy pregnant women), group A (preeclamptic women with chronic periodontitis), and group B (preeclamptic women without chronic periodontitis). Demographic variables and periodontal parameters were recorded. Other variables such as systolic blood pressure (SBP) and diastolic blood pressure (DBP) and the urine protein content were also estimated. RCB, namely Porphyromonas gingivalis (Pg), Treponema denticola (Td), and Tenerella forsythia (Tf), were assessed in both subgingival plaque samples and placental samples of all the pregnant participants in the study. RESULTS: The mean weight, mean body mass index, mean SBP, mean DBP, and mean urine protein content were significantly elevated in group A and group B when compared to the control group. Preeclamptic women with chronic periodontitis (group A) had higher levels of plaque index, probing pocket depth, bleeding on probing, and clinical attachment level as compared with the other groups. The numbers of the RCB were found to be elevated in group A, out of which Pg was found to be more prevalent. CONCLUSIONS: Our findings indicate that the periodontal indices, blood pressure, and urine protein content were found to be higher in preeclamptic women with periodontitis. Hence, reducing the periodontal bacterial load in pregnant women via good oral hygiene maintenance would further reduce the putative risk of adverse pregnancy outcomes including preeclampsia in these women.

Suppression of Tumorigenicity 2 Pro-Inflammatory Biomarker Linking Diabetes Mellitus and Periodontitis: A Pilot Study.

BACKGROUND Suppression of tumorigenicity 2 (ST2) is a member of the interleukin (IL)-1 family and has 2 isoforms: ST2L, a transmembrane form, and ST2, a soluble form. IL-33 can act as an immune system alarm signal when released by damaged cells, which in turn activates other cells expressing the ST2 receptor. This can cause inflammatory cytokines to be released and produced, as well as trigger osteoclastogenesis. This study aimed to investigate the levels of soluble ST2 in gingival samples. MATERIAL AND METHODS The study population consisted of 30 individuals. The participants were divided into 3 groups: healthy participants, patients with periodontitis, and patients with periodontitis and diabetes mellitus. Periodontitis was determined using probing depth, clinical attachment loss, and gingival index. Patients with stage 2 to 4 periodontitis met the inclusion criteria. Gingival crevicular fluid (GCF) was collected for quantification of samples for ST2 levels by using an enzyme immunoassay. RESULTS The mean±standard deviation of ST2 GCF concentrations was relatively high (558.87±68.99) in the group with periodontitis and diabetes mellitus, compared with that of the periodontitis group (452.06±54.18) and healthy group (252.82±87.9). CONCLUSIONS GCF ST2 values were found to be a marker of inflammatory activities. Thus, GCF ST2 could be a potential biomarker for the diagnosis of periodontitis as well as systemic diseases, such as diabetes mellitus. This pilot study was limited by a small number of participants. To confirm the associations, more large-scale investigations should be conducted.

Dose-Dependent Effects of Melatonin on the Viability, Proliferation, and Differentiation of Dental Pulp Stem Cells (DPSCs).

(1) Background: Dental pulp stem cells (DPSCs) are derived from pulp tissue lodged within human teeth and are mesenchymal in origin. These DPSCs have been demonstrated to dissociate into clusters of various cell lineages and are very easy to isolate, culture, and expand. Melatonin, a multifaceted molecule with a spectrum of effects in the human body, is known to influence stem cell viability, proliferation, and differentiation, but little is known about the impact melatonin has on the capacity of DPSCs to differentiate into adipocytes, osteocytes, and chondrocytes. The primary objective of this research was to explore the impact that melatonin has on proliferation, and the capacity of DPSCs to differentiate into adipocytes, osteocytes, and chondrocytes. (2) Methodology: DPSCs were extracted from 12 healthy human teeth, cultured, and expanded. Flow cytometry was performed to examine the surface stem cell markers. Further, melatonin was added to the cultured DPSCs in various concentrations, to assess cytotoxicity using an MTT assay. Following this, the DPSCs were tested for their proliferative ability, as well as adipogenic, osteogenic, and chondrogenic differentiation capabilities under the influence of variable concentrations of melatonin. (3) Results: DPSCs obtained from human teeth demonstrated surface characteristics of mesenchymal stem cells, as shown by the positive expression of CD105, CD90, and CD73 markers. An MTT cytotoxicity assay revealed that melatonin was well tolerated by the cells at low (1 µM) and high (25 µM) concentrations. Assessment of DPSC cell differentiation elucidated that melatonin at 1 µM and 25 µM concentrations with the induction media stimulated DPSCs to differentiate into osteocytes, but did not have much influence on adipogenic and chondrogenic differentiation. (4) Conclusions: Melatonin could be used in stem cell and tissue engineering applications for osteogenic differentiation of DPSCs and could protect these cells due to its cytoprotective, immunomodulatory, and antioxidant roles, in addition to being an osteopromoter molecule.

Evaluation of Mesiodistal Root Angulation of Permanent Incisors, Canines, and First Pre-Molars by Orthopantomogram Dental Imaging Findings in 296 Children Aged 6-14 Years.

BACKGROUND Early pre-eruptive inclination changes of the first premolar (FP) and its associative changes with canine (C) inclination are important to predict canine impaction. This study aimed to evaluate the mesiodistal root angulation of permanent lateral incisors (LI), canines, and first molars by orthopantomogram dental imaging in 296 children ages 6-14 years at a single center in India. MATERIAL AND METHODS The total number of participants was 296, with equal numbers of boys and girls divided into 4 age groups: 6-8 years, 8-10 years, 10-12 years, and 12-14 years. Angles between lateral incisor, erupting canine, and first pre-premolar with midline were measured on an orthopantomogram (dental imaging which includes all the teeth with TMJ). The angle between the erupting C with LI and erupting C with FP was measured. Pearson's correlation was also evaluated between the movement of the erupting canine with lateral incisor and erupting canine with erupting first premolar. RESULTS There was a significant difference in the angular values of different age groups (P≤0.05). The movements between LI, C, and FP were moderately correlated boys and girls aged 6-12 years. CONCLUSIONS The findings from this study showed that in boys and girls aged 6-14 years, eruption of the upper canine tooth was synchronized with eruption of the LI and FP.

Marginal and Internal Gap of Metal Copings Fabricated Using Three Types of Resin Patterns with Subtractive and Additive Technology: An In Vitro Comparison.

This study analyzes the evidence of the marginal discrepancy and internal adaptation of copings fabricated using three types of resin patterns with subtractive (milling) and additive technology (3D printing), as it is not widely reported. Working casts (n = 15) were scanned and patterns were completed using computer-aided designing (CAD). Resin patterns were fabricated using the designed data and divided into three groups according to the method of fabrication of patterns: subtractive technology-CAD milled polymethyl methacrylate resin (Group-PMMA), additive technology [digital light processing (DLP) technique]-acrylonitrile-butadiene-styrene (ABS) patterns (Group-ABS), and polylactic acid (PLA) patterns (Group-PLA). Resin patterns were casted with Cobalt-Chromium (Co-Cr) alloy (lost wax technique). Internal and marginal gaps of the metal copings were analyzed with the replica technique under optical microscope. The Kruskal-Wallis test was used to compare values among the groups, and post hoc multiple tests confirmed the specific differences within the groups. The median marginal gap was least for CAD milled resin patterns, followed by PLA printed resin patterns and ABS printed resin patterns. There were significant differences between Group-PMMA and Group-PLA and Group-ABS (p = 0.0001). There was no significant difference between Group-PLA and Group-ABS (p = 0.899). The median internal gap was least for metal copings fabricated from Group-PLA, followed by Group-ABS and Group-PMMA. The differences were not statistically significant (p = 0.638) for the internal gap. Full metal Co-Cr copings fabricated from the milled PMMA group had a better marginal fit, followed by the PLA and ABS printed groups. Copings fabricated with the PLA printed group had the best internal fit, though the values were statistically insignificant between the groups.

Comparison of Tensile Bond Strength of Fixed-Fixed Versus Cantilever Single- and Double-Abutted Resin-Bonded Bridges Dental Prosthesis.

Resin-bonded fixed dental prostheses (RBFDP) are minimally invasive alternatives to traditional full-coverage fixed partial dentures as they rely on resin cements for retention. This study compared and evaluated the tensile bond strength of three different resin-bonded bridge designs, namely, three-unit fixed-fixed, two-unit cantilever single abutment, and three-unit cantilever double-abutted resin-bonded bridge. Furthermore, the study attempted to compare the tensile bond strengths of the Maryland and Rochette types of resin-bonded bridges. Based on the inclusion and exclusion criteria, a total of seventy-five extracted maxillary incisors were collected and later were mounted on the acrylic blocks. Three distinct resin-bonded metal frameworks were designed: three-unit fixed-fixed (n = 30), two-unit cantilever single abutment (n = 30), and a three-unit cantilever double abutment (n = 30). The main groups were further divided into two subgroups based on the retainer design such as Rochette and Maryland. The different prosthesis designs were cemented to the prepared teeth. Later, abutment preparations were made on all specimens keeping the preparation as minimally invasive and esthetic oriented. Impression of the preparations were made using polyvinyl siloxane impression material, followed by pouring cast using die stone. A U-shaped handle of 1.5 mm diameter sprue wax with a 3 mm hole in between was attached to the occlusal surface of each pattern. The wax patterns were sprued and cast in a cobalt-chromium alloy. The castings were cleaned by sandblasting, followed by finishing and polishing. Lastly, based on the study group, specimens for Rochette bridge were perforated to provide mechanical retention between resin cement and metal, whereas the remaining 15 specimens were sandblasted on the palatal side to provide mechanical retention (Maryland bridge). In order to evaluate the tensile bond strength, the specimens were subjected to tensile forces on a universal testing machine with a uniform crosshead speed. The fixed-fixed partial prosthesis proved superior to both cantilever designs, whereas the single abutment cantilever design showed the lowest tensile bond strength. Maryland bridges uniformly showed higher bond strengths across all framework designs. Within the limitations of this study, the three-unit fixed-fixed design and Maryland bridges had greater bond strengths, implying that they may demonstrate lower clinical failure than cantilever designs and Rochette bridges.

Recent Advances in the Diagnosis of Enamel Cracks: A Narrative Review.

Cracked teeth can pose a diagnostic dilemma for a clinician as they can mimic several other conditions. The constant physiological stress along with any pathological strain like trauma or iatrogenic causes can lead to the development of microcracks in the teeth. Constant exposure to immense stress can cause the progression of these often-undiagnosed tooth cracks to cause tooth fractures. This review aims to outline the etiology of tooth cracks, their classification, and recent advances in the diagnosis of enamel cracks. Diagnosing a cracked tooth can be an arduous task as symptoms differ according to the location and extension of the incomplete fracture. Early detection is critical because restorative treatment can prevent fracture propagation, microleakage, pulpal or periodontal tissue involvement, and catastrophic cusp failure. Older methods of crack detection are not sensitive or specific. They include clinical examination, visual inspection, exploratory excavation, and percussion test. The dye test used blue or gentian violet stains to highlight fracture lines. Modern methods include transillumination, optical coherence tomography Swept-Source Optical Coherence Tomography (SSOCT), near-infrared imaging, ultrasonic system, infrared thermography, and near-infrared laser. These methods appear to be more efficacious than traditional clinical dental imaging techniques in detecting longitudinal tooth cracks. Clinically distinguishing between the various types of cracks can be difficult with patient-reported signs and symptoms varying according to the location and extension of the incomplete fracture. Cracks are more common in restored teeth. Technological advances such as transillumination allow for early detection and enhanced prognosis.

Comparative Evaluation of Microleakage of Flowable Composite Resin Using Etch and Rinse, Self-Etch Adhesive Systems, and Self-Adhesive Flowable Composite Resin in Class V Cavities: Confocal Laser Microscopic Study.

The essential factor in determining the preservation of restoration is the marginal seal. Restoring cervical lesions with a resin composite has always been a challenge. Composite resins with various viscosities and different bonding systems are being researched to reduce the microleakage. Confocal laser scanning microscopy (CLSM) is the latest non-destructive technique for visualizing the microleakage. Objectives: To evaluate and compare the microleakage of Universal Flo composite resin (G-aenial) using etch and rinse adhesive system ER-2 steps (Adper Single Bond 2), self-etch adhesive system SE-1 step (G-Bond), and self-adhesive flowable composite resin (Constic) in Class V cavities using a confocal laser scanning microscope. Materials and Method: Class V cavities were prepared on 27 caries-free human extracted premolar teeth on the buccal and lingual surfaces with standardized dimensions of 2 mm height, width 4 mm, and a depth of 2 mm. After the cavity preparation, all teeth were randomly divided into three groups, namely Group-I: G-aenial Universal Flo with Single Bond 2 (n = 9 teeth); Group-II: G- aenial Universal Flo with G-Bond (n = 9 teeth), and Group-III: Constic (n = 9 teeth). The prepared and restored specimens were then subjected to thermocycling for 500 cycles in a water bath at 5 °C and 55 °C with a dwelling time of 30 s. The specimens were placed in 0.6% aqueous rhodamine dye for 48 h. Sectioning was carried out bucco-lingually and specimens were evaluated for microleakage under a confocal laser scanning microscope. Results: There was a significant difference (p = 0.009) in microleakage when comparing total etch and rinse, specifically between Adper Single Bond 2 ER-2 steps (fifth generation) and self-adhesive flowable composite resin, which is Constic. There was more microleakage in the self-etch bonding agent, particularly G-Bond, SE-1 step (seventh generation), when compared to ER-2 steps (fifth generation bonding agent); however, the results were not statistically significant (p = 0.468). The self-adhesive flowable composite resin showed more microleakage than SE-1 step and ER-2 steps. Conclusions: None of the adhesive systems tested were free from microleakage. However, less microleakage was observed in the total etch and rinse, especially Adper Single Bond 2 (ER-2 steps), than the self-etch adhesive system SE-1 step and self-adhesive flowable composite resin. Clinical significance: Constant research and technological advancements are taking place in dentin adhesives to improve the marginal seal. This has led to the evolution of total acid-etching dentin bonding agents termed as etch and rinse (ER)-2 steps (fifth generation dentin bonding agents) and self-etching (SE) 2 steps, and SE-1 step dentin bonding agents termed as the sixth and seventh generation bonding agents, respectively.

Evaluating the Effect of Tideglusib-Loaded Bioactive Glass Nanoparticles as a Potential Dentine Regenerative Material.

Dental pulp treatment is the least intrusive procedure currently available for preserving the vitality of the pulp. Several studies are underway to improve the bioactivity of pulp capping materials. Tideglusib isa potent anti-inflammatory, antioxidant, and a regenerative drug developed against Alzheimer's disease and has been shown to be effective in the treatment of dental cavities. However, its bioactive properties encapsulated within the nanoparticles as a component of pulp capping material are largely unknown. In this study, tideglusib-loaded bioactive glass nanoparticles were synthesized (tideglusib-BgNPs) and mixed at various concentrations into the calcium silicate cement to testits physiomechanical and bioactivitiescompared with biodentine (control). The calcium silicate cement with 10wgt% tideglusib-BgNPs showed comparable physiomechanical properties to that of biodentine. Additionally, the assessment of cytotoxicity and bioactivity (cell proliferation, wound healing, and cell migration assays) showed increased bioactivity in terms of better wound healing, increased proliferation, and better migration of human dental pulp stem cells than biodentine. These findings suggest new opportunities to use tideglusib-BgNPs in pulp therapy.

The Anticariogenic Efficacy of Nano Silver Fluoride.

Dental caries is a common chronic disease, and anyone can be at threat of it throughout their lifespan. In school-aged children, dental caries is the most frequent disease related with oral health. Contemporary dental caries management focuses on non-restorative, non-invasive, and micro-invasive therapeutic techniques that effectively eliminate the caries progression at the lesion level and decrease the loss of healthy tooth structure. One of these strategies is to use caries apprehending agents with antibacterial and remineralizing characteristics. Due to recent regulatory approval in the United States, the use of silver diamine fluoride (SDF) for the therapy of dental caries has received substantial interest. SDF has successfully prevented and reversed both primary tooth caries and permanent teeth root caries. Even though SDF is an effective anti-caries agent, but it is associated with certain drawbacks like gum irritation, metallic taste, and irreversible dark stains on applying on cavities. As an alternative agent Nano Silver Fluoride (NSF) is preferable because it performs like SDF without tooth staining. It has comparable preventive and antibacterial activities as SDF. Further, it is ergonomic, economic and safe in children and adults. The current article aims to highlight the superior properties of NSF as a better anti-caries agent outstripping the limitations of discoloration of SDF.

Zinc Oxide Nanoparticles: A Review on Its Applications in Dentistry.

Nanotechnology in modern material science is a research hot spot due to its ability to provide novel applications in the field of dentistry. Zinc Oxide Nanoparticles (ZnO NPs) are metal oxide nanoparticles that open new opportunities for biomedical applications that range from diagnosis to treatment. The domains of these nanoparticles are wide and diverse and include the effects brought about due to the anti-microbial, regenerative, and mechanical properties. The applications include enhancing the anti-bacterial properties of existing restorative materials, as an anti-sensitivity agent in toothpastes, as an anti-microbial and anti-fungal agent against pathogenic oral microflora, as a dental implant coating, to improve the anti-fungal effect of denture bases in rehabilitative dentistry, remineralizing cervical dentinal lesions, increasing the stability of local drug delivery agents and other applications.

Dental Caries and Oral Health Status of Psychoactive Substance Abusers.

Substance-abuse disorders are universally associated with comorbid illness. Tobacco is a widely abused substance across the globe and presents a critical public health problem. The precise correlation between tobacco use and dental caries remains unclear. Thus, the present study aimed to evaluate the correlation between tobacco use and dental caries. METHODOLOGY: Based on selection criteria, a total of 270 (age 20-50 years) participants were included in the study, and were categorized as group A (n = 135), consisting of tobacco users, and group B (n = 135), comprising healthy controls (non-users). The Decayed, Missing, and Filled index (DMFT) was used to measure caries status. The Simplified Oral Hygiene index was used to evaluate oral health. RESULTS: The tobacco group reported the use of cigarettes; smokeless tobacco in indigenous forms, such as gutka (areca nut, tobacco, and slaked lime), betel nut chewing; and a combination. Individuals with tobacco habits had a higher prevalence of dental caries (Mean DMFT 4.73 ± 4.32) compared to the non-habit group (Mean DMFT 3.17 ± 3.11 (p = 0.001). The Oral Hygiene index was significantly higher (indicating bad/poor oral hygiene) in tobacco abusers than those of non-users (p = 0.0001). Duration and frequency of tobacco use were correlated with the levels of moderate and severe caries (p = 0.001). CONCLUSION: Psychoactive substance abuse, such as smoking/smokeless tobacco consumption, is associated with higher prevalence of dental caries.

Differential effects of integrase strand transfer inhibitors, elvitegravir and raltegravir, on oligodendrocyte maturation: A role for the integrated stress response.

Regardless of adherence to combined antiretroviral therapy, white matter and myelin pathologies persist in patients with HIV-associated neurocognitive disorders, a spectrum of cognitive, motor, and behavioral impairments. We hypothesized that antiretroviral therapy alters the maturation of oligodendrocytes which synthesize myelin. We tested whether specific frontline integrase strand transfer inhibitors would alter oligodendrocyte differentiation and myelination. To model the effect of antiretrovirals on oligodendrocytes, we stimulated primary rat oligodendrocyte precursor cells to differentiate into mature oligodendrocytes in vitro in the presence of therapeutically relevant concentrations of elvitegravir or raltegravir and then assessed differentiation with lineage specific markers. To examine the effect of antiretrovirals on myelination, we treated mice with the demyelinating compound cuprizone, for 5 weeks. This was followed by 3 weeks of recovery in absence of cuprizone, during which time some mice received a daily intrajugular injection of elvitegravir. Brains were harvested, sectioned and processed by immunohistochemistry to examine oligodendrocyte maturation and myelination. Elvitegravir inhibited oligodendrocyte differentiation in vitro in a concentration-dependent manner, while raltegravir had no effect. Following cuprizone demyelination, administration of elvitegravir to adult mice reduced remyelination compared with control animals. Elvitegravir treatment activated the integrated stress response in oligodendrocytes in vitro, an effect which was completely blocked by pretreatment with the integrated stress response inhibitor Trans-ISRIB, preventing elvitegravir-mediated inhibition of oligodendrocyte maturation. These studies demonstrate that elvitegravir impairs oligodendrocyte maturation and remyelination and that the integrated stress response mediates this effect and may be a possible therapeutic target.