Tooth Surface Research Articles

Intelligent Inspection Method and System of Plastic Gear Surface Defects Based on Adaptive Sample Weighting Deep Learning Model.

After injection molding, plastic gears often exhibit surface defects, including those on end faces and tooth surfaces. These defects encompass a wide range of types and possess complex characteristics, which pose challenges for inspection. Current visual inspection systems for plastic gears suffer from limitations such as single-category defect inspection and low accuracy. There is an urgent industry need for a comprehensive and accurate method and system for inspecting defects on plastic gears, with improved inspection capability and higher accuracy. This paper presents an intelligent inspection algorithm network for plastic gear defects (PGD-net), which effectively captures subtle defect features at arbitrary locations on the surface compared to other models. An adaptive sample weighting method is proposed and integrated into an improved Focal-IoU loss function to address the issue of low inspection accuracy caused by imbalanced defect dataset distributions, thus enhancing the regression accuracy for difficult defect categories. CoordConv layers are incorporated into each inspection head to improve the model's generalization capability. Furthermore, a dataset of plastic gear surface defects comprising 16 types of defects is constructed, and our algorithm is trained and tested on this dataset. The PGD-net achieves a comprehensive mean average precision (mAP) value of 95.6% for the 16 defect types. Additionally, an online inspection system is developed based on the PGD-net algorithm, which can be integrated with plastic gear production lines to achieve online full inspection and automatic sorting of plastic gear defects. The entire system has been successfully applied in plastic gear production lines, conducting daily inspections of over 60,000 gears.

Regenerative potential of mesoporous silica nanoparticles scaffold on dental pulp and root maturation in immature dog’s teeth: a histologic and radiographic study

ObjectiveTo evaluate histologically and radiographically the potential of dog’s immature roots with apical periodontitis to regenerate after regenerative endodontic treatment using mesoporous silica nanoparticles (MSNs) with/without bone morphogenic protein (BMP-2) as scaffolds.MethodsIn 4 mongrel dogs, 56 immature teeth with 96 roots were infected, resulting in necrotic pulps and periapical pathosis. According to the evaluation time (Group I = 30 days and Group II = 90 days), 90 roots were divided into two equal groups (45 roots each) and 6 roots used to replace any lost root during the procedure. The two main groups were further divided according to treatment protocol into 5 subgroups (9 roots each): blood clot (BC subgroup), mesoporous silica nanoparticles scaffold only (MSNs subgroup), mesoporous silica nanoparticles impregnated with BMP2 (MSNs + BMP2 subgroup), infected teeth without treatment (+ ve control subgroup) and normal untouched teeth (-ve control subgroup). All teeth surfaces were coated with Tincture iodine and calcium hydroxide was applied prior to treatment protocols. Then, teeth were restored with glass ionomer filling to seal the remaining part of the access cavity. Radiography evaluation of the increase in root length, root thickness and occurrence of apical closure were performed. Following the sacrifice of the two dogs at each time of evaluation, histopathological analysis was performed and included the inflammatory cells count, bone resorption, tissue ingrowth, deposition of hard tissue, and closure of the apical part. All data were statistically analyzed.ResultsCompared to BC subgroup, MSNs and MSNs + BMP-2 subgroups exhibited significant higher increase in root length and thickness as well as higher vital tissue in-growth and new hard tissue formation in group II (P < 0.05). MSNs + BMP-2 subgroup had significant higher increase in root length and thickness as well as significant lower inflammatory cell count than MSNs subgroup in both groups (P < 0.05). There were no significant differences between MSNs and MSNs + BMP-2 subgroups regarding new hard tissue formation in both groups and apical closure in group I (P > 0.05).ConclusionMSNs with/without BMP-2 scaffolds enabled the continuing growth of roots in immature teeth with necrotic pulps and periapical pathosis. Addition of BMP-2 to MSNs scaffold improved its outcome in regenerative endodontics.Clinical relevanceMSNs with/without BMP-2 scaffolds may alternate blood clot for regenerative endodontic treatment of immature teeth with necrotic pulps.

Aggregatibacter actinomycetemcomitans: From the Oral Cavity to the Heart Valves.

Aggregatibacter actinomycetemcomitans (A. actinomycetecomitans) is a Gram-negative bacterial species that is an essential component of the oral microbiota. Due to its aggregative properties, it plays a role in the pathogenesis of human diseases. The presence of the surface proteins Fim, Briae, and microvesicles enables the bacterium to adhere to the epithelial surface and the tooth's surface. The presence of leukotoxin A (LtxA), which plays an important role in the pathogenicity of the bacterium, has been associated with both periodontitis and the etiology of rheumatoid arthritis (RA). A. actinomycetecomitans is also associated with several other systemic diseases and complications, such as endocarditis and different abscesses. In addition to leukotoxin A, A. actinomycetecomitans possesses several different virulence factors, including bacteriocins, chemotaxis inhibitory factors, cytotoxic factors, Fc-binding proteins, immunosuppressive factors, lipopolysaccharide collagenase, fibroblast inhibitory factors, antibiotic resistance determinants, adhesins, invasive factors and factors that inhibit the function of polymorphonuclear leukocytes. The ability of A. actinomycetemcomitans lipopolysaccharide to induce macrophages to secrete the interleukins IL-1, IL-1β, and tumor necrosis factor (TNF) is of considerable importance. The primary etiologic factor in the pathogenesis of periodontal disease is the oral biofilm colonized by anaerobic bacteria. Among these, A. actinomycetemcomitans occupies an important place as a facultative anaerobic bacterium. In addition, A. actinomycetemcomitans possesses many virulence factors that contribute to its potential to cause cancer. This article provides an overview of the virulence factors of A. actinomycetecomitans and its association with various systemic diseases, its oncogenic potential, and the treatment options for infections caused by A. actinomycetecomitans.

Influence of discrete laser surface melting on scuffing resistance of W6Mo5Cr4V2 steel gear

The gear transmission system is advancing towards high-speed and heavy-duty applications. Among the main failure modes of the system, tooth surface scuffing due to increased tooth surface temperature has emerged as a prominent concern in mechanical transmission. Addressing the enhancement of gear scuffing resistance has thus become an urgent challenge in this field. This paper utilized discrete laser surface melting (DLSM) treatment to create discrete laser surface melted (DLSMed) units on the surface of W6Mo5Cr4V2 steel gears, resembling the radial ribs found on the surface of Limaria basilica. The paper investigated the size, hardness, residual austenite content, and residual stress of the DLSMed units at varying current intensities and laser frequencies. Microstructural observations were conducted on the DLSMed units, followed by gear scuffing experiments performed on the Forschungsstelle für Zahnräder und Getriebebau (FZG) testing machine. The experimental findings revealed that the change in laser frequency had a clearly weaker impact on the size of the DLSMed unit compared to current intensity. The DLSMed unit consisted of two parts: the melting zone (MZ) and the heat-affected zone (HAZ), with equiaxed and dendritic microstructures, respectively. Both zones exhibited refinement with increasing current intensity and laser frequency. Moreover, the microhardness of the DLSMed unit showed significant improvement compared to that of as-received gears. The scuffing resistance of DLSMed gears was found to be closely linked to their initial surface roughness. Residual stress formation in DLSMed gears was attributed to thermal stress and microstructural stress. The distribution pattern of DLSMed units had varying effects on the scuffing load-carrying capacity of DLSMed gears. Specifically, DLSMed gears with transverse distribution of DLSMed units demonstrated a 12.5% improvement in anti-scuffing performance compared to those with longitudinal distribution. Finally, this paper elucidated the mechanism through which DLSM enhances the scuffing resistance of W6Mo5Cr4V2 steel gears.

Reliability of impedance spectroscopy versus digital radiograph and ICDAS-II in occlusal caries detection: a prospective clinical trial

The traditional methods in early caries detection had many limitations. So, this study aimed to evaluate the clinical performance of alternating current impedance spectroscopy ACIST in comparison with digital radiograph and ICDAS-II in detection of occlusal carious lesions. Occlusal surfaces of molar and premolar teeth from 40 adult participants were examined by two observers using three diagnostic methods: (1) international caries detection and assessment system (ICDAS-II) (2) digital radiograph (DR) and (3) Cariescan Pro device (ACIST). Agreement analysis and the difference in sensitivities and specificities were evaluated. The results showed an excellent agreement in the different groups. The difference from the visual tactile against ACIST scoring for enamel caries detection, was statistically significant (p = 0.012) and the agreement was moderate (k = 0.509). For dentinal caries the difference was not statistically significant (p > 0.05) and the agreement was similarly moderate (k < 0.6). The difference from the digital radiograph against ACIST scoring, for enamel caries, digital radiography had significantly higher sensitivity and specificity than ACIST (p < 0.001) while for dentinal caries detection and overall, ACIST had higher sensitivity and digital radiography had higher specificity and the difference was statistically significant (p < 0.001). Visual-tactile examination is a considered as feasible and valid technique for occlusal caries detection, digital radiography is superior to ACIST in diagnosing enamel caries, but it could underestimate the caries depth, ACIST is a reliable tool for detecting occlusal caries in dentin.

Let the black tea and green tea take care of your oral health — A short review of the antimicrobial activity of black tea and green tea extracts on

Dental caries is a major global concern and source of great trouble worldwide. It is one of the most common chronic oral diseases in the world that affects both adults and children. The prevalence of DMFT index as a diagnostic criterion in the estimation of dental caries in the age group of 3–18 years was found to be 57%, whereas in patients aged above 18 years, it was much higher that is 77%.Many studies have been carried out all over the world to find the cause behind it, and the main cause, which was well accepted by the people, was the action of pathogenic bacterial microflora such as ( in the oral cavity on the tooth surfaces. These bacteria strongly adhere to the tooth surface and produce lactic acid after fermentation of sucrose and various carbohydrates, which is responsible for the cavitation in the teeth. Many experiments and efforts have been made to remove from the oral cavity, like antibiotics, oral drugs, and more, which are beneficial but have side effects after long-term use, such as vomiting, diarrhea, resistance, teeth staining, etc.That's why search ended at tea which is becoming a popular beverage and a widely consumed drink these days that has anti-streptococcal properties with least of side effect.India's tea usage changed over time from being a colonial export to a regular beverage. With over 29% of the global tea production, India is one of the world's biggest producers and consumers. In India, tea has long been closely linked to the medicinal herbs that have long been used for both therapeutic purposes and general well-being.

Chemical composition, cytotoxicity, antimicrobial, antibiofilm, and anti-quorum sensing potential of Mentha Piperita essential oil against the oral pathogen Streptococcus mutans

ABSTRACT Dental caries is a highly prevalent oral disease affecting billions of individuals globally. The disease occurs chemically as a result of breakdown of the tooth surface attributed to metabolic activity in colonizing biofilm. Biofilms, composed of exopolysaccharides and proteins, protect bacteria like Streptococcus mutans, which is notable for its role in tooth decay due to its acid-producing abilities. While various antimicrobial agents may prevent biofilm formation, these drugs often produce side effects including enamel erosion and taste disturbances. This study aimed to examine utilization of the Mentha piperita essential oil as a potential antibiofilm activity agent against S. mutans. M. piperita oil significantly (1) reduced bacterial biofilm, (2) exhibited a synergistic effect when combined with chlorhexidine, and (3) did not induce cell toxicity. Chemical analysis identified the essential oil with 99.99% certainty, revealing menthol and menthone as the primary components, constituting approximately 42% and 26%, respectively. Further, M. piperita oil eradicated preformed biofilms and inhibited biofilm formation at sub-inhibitory concentrations. M. piperita oil also interfered with bacterial quorum sensing communication and did not produce any apparent cell toxicity in immortalized human keratinocytes (HaCaT). M. piperita represented an alternative substance for combating S. mutans and biofilm formation and a potential combination option with chlorhexidine to minimize side effects. An in-situ performance assessment requires further studies.

Potency of Strawberry Extract (Fragaria X Annanassa) as Stain Removal Strips Against Extrinsic Stain on the Surface of the Teeth of Adolescents Aged 18-25 Years

Extrinsic stain is a staining of teeth that is attached directly to the surface of the tooth. Disorders caused by stains are causing aesthetic problems that can have a considerable psychological impact, especially if they occur in the anterior tooth. Stains are difficult to clean just by brushing your teeth. Utilizing natural strawberry ingredients as Stain Removel Strips for an alternative to cleaning extrinsic stains on the surface of teeth. Objective: Proven administration of Stain Removal Strips strawberry extract (Fragaria x Ananassa) effectively cleans extrinsic stains on the surface of teeth. Method: This study used the Quasy experimental method with a pretest posttest design with control group. Research sampling was carried out by purposive sampling. The sample consisted of 20 people divided into 2 groups. The control group with 6% hydrogen peroxide strips and the intervention group with 40% strawberry extract stain removal strips twice a day with a duration of 30 minutes for 7 days. Results: The results showed that giving strawberry extract Stain Removal Strips was 40% effective in cleaning extrinsic stains on day 3 and day 7 against extrinsic stains on the tooth surface with values of p = 0.009 and p = 0.002 (p &lt; 0.05) compared to the control group. Conclusion: Stain Removal Strips 40% strawberry extract has potential as an alternative to cleaning extrinsic stains on tooth surfaces.

Virtual bracket removal: a comparative assessment of different software packages

BackgroundHigh precision intra-oral scans, coupled with advanced software, enable virtual bracket removal (VBR) from digital models. VBR allows the delivery of retainers and clear aligners promptly following debonding, thus reducing the patients' appointments and minimizing the likelihood of tooth movement. The objective of this study was to compare the enamel surface before bonding and after VBR using three different Computer-aided design (CAD) software and to compare their accuracy.MethodsMaxillary scans of 20 participants starting orthodontic treatment were selected for inclusion in the study, who exhibited mild to moderate crowding and required bonding of brackets on the labial surface of permanent maxillary teeth (from the maxillary left first molar to the maxillary right first molar). Two intra-oral scans were conducted on the same day, before bonding and immediately after bonding using CEREC Omnicam (Sirona Dental Systems, Bensheim, Germany). The virtual removal of the brackets from the post-bonding models was performed using OrthoAnalyzer (3Shape, Copenhagen, Denmark), Meshmixer (Autodesk, San Rafael, Calif, USA), and EasyRx (LLC, Atlanta, GA, USA) software. The models that underwent VBR were superimposed on the pre-bonding models by Medit Link App (Medit, Seoul, South Korea) using surface-based registration. The changes in the enamel surface following VBR using the three software packages were quantified using the Medit Link App.ResultsThere was a significant difference among the 3Shape, Meshmixer, and EasyRx software in tooth surface change following VBR. Specifically, EasyRx exhibited lower levels of accuracy compared to the other two VBR software programs (p<.001, p<.001). A significant difference in enamel surface change was observed between tooth segments across all software groups, in both incisors and molars, with VBR of the molars exhibiting the lowest level of accuracy (3Shape p=.002, Meshmixer p<.001, EasyRx p<.001). Regarding the direction of tooth surface changes following VBR, it was observed that all three groups exhibited a significant increase in the percentage of inadequate bracket removal across all teeth segments.Conclusions3Shape and Meshmixer manual VBR software were found to be more accurate than EasyRx automated software, however, the differences were minimal and clinically insignificant.

Effect of tooth surface wear on dynamic characteristics of spur gear transmission system

The meshing stiffness and system dynamic characteristics caused by gear wear fault are studied. Firstly, potential energy method was used to model and solve the meshing stiffness of gears and the effect of wear on the meshing stiffness and static transfer error was analyzed. A 6-dof spur gear dynamics model was established considering various nonlinear factors, and the dynamic responses of the spur gear system under various wear degrees were analyzed by using time domain, spectrum, phase plane, and Poincare mapping. Finally, the visual test platform of the gear box is built, and the wear condition and dynamic response of the gear box under different wear cycles are analyzed. Results show that the meshing stiffness of gear decreases due to wear, and the meshing stiffness of double tooth decreases more than that of single tooth. In addition, the static transmission errors caused by wear changes periodically with meshing frequency. Wear causes the vibration response of gear system to become complex gradually, and the nonlinear of the system is enhanced, which changes from single period motion to quasi period motion. Results can provide theoretical support for gear wear reduction, life extension, vibration reduction, and noise reduction and lubrication improvement.

Measurement method of spherical radius size of differential planetary gear tooth surface based on 3D vision

Abstract In order to accurately measure the spherical radius dimensions of planetary gear tooth surfaces, we propose a non-contact measurement method based on 3D vision technology. Firstly, the point cloud data of the planetary gear captured by the laser 3D profiler is preprocessed, and the tooth surface point cloud is extracted. Next, based on the structural characteristics of the planetary gear tooth surface, a uniform slicing and sampling algorithm is used to extract circular contour points where the tooth surface point cloud intersects with the slicing planes. These points are then projected onto a two-dimensional plane, where an improved RANSAC algorithm is used to precisely fit each circular cross-section. Contour points associated with significant fitting errors are removed based on a set tolerance value. Finally, an improved differential evolution algorithm is used to perform a three-dimensional spherical fitting on the contour points that meet the tolerance criteria, achieving accurate measurement of the spherical radius of the planetary gear tooth surfaces. Experimental results demonstrate that the repeatability error of the proposed method is ±0.02 mm, with a maximum absolute error of 0.026 mm and an average measurement time of 4.76 s. The method exhibits high robustness and measurement accuracy, meeting practical engineering measurement requirements.

Evaluation of Lateral and Vertical Gingival Displacement Produced by Three Different Gingival Retraction Systems using Impression Scanning: An in-Vivo Original Study

Isolation of the prepared margin along with control of gingival fluid and haemorrhage is an important factor to register finish lines, which can be achieved by displacing the gingiva away from the abutment which helps in better visualization of the prepared tooth surface. This study utilized digital scanning of rubber based impression material to compare the amount of gingival displacement produced by 3M ESPE capsule, plain retraction cord and impregnated retraction cord.  Aims: The aim of the study was to compare lateral and vertical gingival displacement produced by the three materials  Settings and Design: Case-Control  Methods and Material: Twenty participants requiring a full coverage restoration were selected. Gingiva around each tooth requiring a crown was retracted using the three materials and a rubber based impression was made. The impression was scanned using EXOCAD software to obtain readings for gingival displacement for control group, non- impregnated cord, impregnated cord and retraction paste.  Statistical analysis used: The scores were analysed in SPSS software using one way ANNOVA and post hoc analysis  Results: Significant difference was seen among all trial groups when compared to control. Highest mean vertical displacement was seen in clinical trial II (non- impregnated cord) followed by trial III ( retraction paste).  Conclusions: Impregnated cord and retraction paste both produced adequate retraction for the margings to be registered. Use of paste was less time consuming and less traumatic for the patient and therefore can be substituted for retraction cords.

Innovative insights into nanofluid-enhanced gear lubrication: Computational and experimental analysis of churn mechanisms

This study offers unique insights into the churn lubrication mechanism in gear transmission systems through the utilization of nanofluids for the first time. Various performance parameters of the prepared nanofluid lubrication oil are measured, along with the discussion of suspension stability. Based on the overset mesh method and VOF multiphase flow model, a rotating fluid domain calculation model considering the nanofluid-air two-phase is proposed. The high-speed nanofluid lubrication experiment platform is established to track churn phenomena and identify the oil volume fraction on the gear surface. Comparing simulation results with experimental data confirms the calculation accuracy in depicting oil flow and churn lubrication. Result shows that the interaction between droplets and the gear surface involves splash, rebound, adhesion, and diffusion. The nanofluid exhibits improved adsorption, resulting in a higher oil volume fraction. When the rotation speed is increased, intensified oil spatter and atomization are observed. The ranking of nanofluid lubrication performance is Al2O3, SiO2, Fe3O4, CuO, and TiO2 particles, which are approximately aligned with contact angle magnitudes. For 3 % nanoparticles concentration, less oil is swung off, more is drawn into the gear meshing zone, and subsequently squeezed out. Image recognition results align with numerical simulation, indicating that the oil distribution of nanofluid is better than that of base fluid lubrication. This work serves as a foundational exploration for future nanofluid lubrication and heat dissipation, offering insights into preventing oil film rupture, tooth surface wear, gluing and other failure mechanisms.

A Mathematical Modeling of Computer Numerical Control Skiving Process for Manufacturing Helical Face Gears Using Sensitivity Matrix Combined With Levenberg–Marquardt Algorithm

Abstract Currently, numerous studies have applied gear skiving processes to produce face gear. However, there remains a significant challenge in achieving a flexible computing model for manufacturing a precise tooth surface for face gear. This study proposes a novel mathematical model that combines the cutter modification method and computer numerical control (CNC)-axis motion modification methods within a unified “closed-loop optimization.” This approach aims to enhance the tooth surface accuracy of skived helical face gears by determining optimal coefficients. Applying the Levenberg–Marquardt algorithm and sensitivity matrix enables the calculation of new polynomial coefficients, ensuring the attainment of gear surfaces with an accuracy grade of B6 (according to the ANSI/AGMA 2009-B01 standard) for each target surface. The proposed methodology involves the generation of a helical skiving cutter using a corrected rack. Subsequently, the cutting path on the CNC machine is optimized by incorporating additional motions expressed in polynomials. A comprehensive skiving simulation is conducted to achieve the desired face-gear surface, which is corrected by specified polynomial coefficients. The proposed model is validated through numerical and machining simulations using vericut software. The results affirm the practicality and efficacy of our approach in achieving the desired accuracy in producing helical face gears through power skiving processes.

Early diagnosis of early childhood caries: A simple novel tool (MAAC charts) for parents and caretakers

Early Childhood Caries (ECC) is a condition associated with nearly 123 risk factors. Among all the risk factors, enamel defects or enamel hypoplasia (ED/EH) has been shown to be the primary risk factor. ED/EH comprises the earliest changes that manifest on newly erupted primary tooth surfaces soon after its eruption. ED/EH appears as white lines or patches, either as demarcated or diffuse opacities on the enamel surface. It is often observed on the labial and buccal surfaces of the newly erupted primary maxillary incisors. A simple self-report tool for mothers/caretakers, healthcare professionals, and primary care workers to diagnose early changes in ECC may facilitate early diagnosis. The MAAC chart was developed to prevent ECC in children with cleft lip and palate. These charts, primarily developed to educate parents, caregivers, healthcare professionals, and primary health care providers, illustrate the variations in ED/EH on the enamel surface (demarcated and diffuse opacities on various maxillary teeth) as a collage of pictures organized as incisors and canines. This paper describes a novel and simple, tool called ‘MAAC charts’ providing guidance on early signs of Early childhood caries (ECC) for health professionals, parents and caretakers. MAAC charts can be useful for Pediatric dentists while providing anticipatory guidance during early first dental visits in their office. Pediatric dentists can suggest paediatricians to use these MAAC charts, in vaccinations clinics and various in/out patient settings to provide oral health related anticipatory guidance. Pediatric dentists can use these MAAC charts in large scale public health campaigns focused on preventing ECC.

Effect of bionic texture on the lubrication efficiency and mechanical efficiency loss for rotating gears

In order to enhance lubrication effectiveness and transmission efficiency in gear transmission, it is imperative to minimize mechanical efficiency losses and frictional wear of the gears during the lubrication process. This paper proposes a bionic design scheme for the tooth surface structure of gears based on the surface texture of bay scallop shells, considering the operational conditions within the gearbox. Firstly, the microstructure of the bay scallop shell surface is analyzed, and a bionic gear mapping model based on the bay scallop shell surface is established. Meanwhile, the oil coverage rate and convective heat transfer coefficient of gear surfaces with different textures was analyzed using finite element analysis. The results showed that the oil coverage rate of gear tooth surfaces with bionic fringes surpassed that of conventional gear lubrication. Thirdly, based on the jet lubrication test calculation, it is proposed that the bionic gear exhibits a lower mechanical efficiency loss and wear mass compared to conventional gears, while the mechanical efficiency loss and wear mass of arc groove gear type lower than that of vertical groove gears. Finally, the optimal structure of the arc groove gear was predicted through orthogonal data analysis, and the validity of the data prediction was verified through experiments and simulations. The optimal combination of texture parameters for the arc groove gear is as follows: a texture depth of 225 μm, a texture width of 275 μm, a texture interval of 275 μm, and a texture length of 1600 μm. As a result, compared with the conventional gear, the lubrication efficiency of the optimized gear is increased by 41.98%, heat dissipation efficiency increased by 32.21%, and mechanical efficiency loss is decreased by 89.39%, the wear mass is reduced by 74.33%.

Fabrication and Characterization of Electrospun Ocimum sanctum and Curcumin-Loaded Nanofiber Membrane for the Management of Periodontal Disease: An In Vitro Study.

Background Periodontal disease is a chronic inflammatory condition that gradually deteriorates the supportive tissues of teeth, eventually leading to tooth loss. Mechanical debridement stands as the gold standard method for treating periodontitis. However, antimicrobial therapy is recommended for optimal results when used alongside mechanical debridement. Numerous studies have investigated local drug delivery as an adjunct to mechanical debridement of affected tooth surfaces. Ocimum sanctum exhibits anti-inflammatory, antioxidant, and antimicrobial properties. Similarly, curcumin, as documented in the literature, demonstrates a broad spectrum of anti-inflammatory and antimicrobial effects. Electrospinning has demonstrated itself to be a highly effective method for fabricating drug-loaded fibers. Electrospun nanofibers containing Ocimum sanctum and curcumin are expected to exhibit greater efficacy due to their increased surface area, facilitating the dispersion of larger quantities of drugs, and their ability to control drug release when employed as a local drug delivery system. This study aims to fabricate and characterize the properties of nanofiber membranes loaded with Ocimum sanctum and curcumin using the electrospinning technique. Methods About 50 mg each of Ocimum sanctum and curcumin were blended with 15% polyvinyl alcohol and 2% chitosan polymer in a 4:1 ratio and left to stir overnight. A 10 mL syringe was filled with this solution, and an 18 G blunt-end needle charged at 15.9 kV was used for extrusion. Continuous fibers were collected onto a collector plate positioned 12 cm from the center of the needle tip, at a flow rate of 0.005 mL/min. The morphology of the fabricated membrane was assessed through scanning electron microscopy (SEM), the strength of the material was assessed through tensile strength analysis using INSTRON, an Electropuls E3000 Universal Testing Machine(INSTRON, Norwood, MA), and the drug release pattern was analyzed using Jasco V-730 UV-visible spectrophotometer(Jasco, Easton, MD). Results The morphology of this nanofiber showed a random distribution of fibers with no bead formation. The average diameter of the membrane was 383±102 nm, and the tensile strength of this material was 1.87 MPa. The drug release pattern showed an initial burst release of Ocimum sanctum, followed by a controlled release in subsequent hours. However, curcumin showed very little drug release because of its solubility. Conclusion In summary, the Ocimum sanctum and curcumin-loaded nanofibers exhibited robust tensile strength, a controlled drug release profile, and uniform drug distribution within the nanofiber membrane. Consequently, it can be concluded that curcumin nanofibers and electrospun Ocimum sanctum serve as valuable agents for local drug delivery in the treatment of periodontitis.

Comparative Evaluation of Microbial Adhesion on Provisional Crowns Fabricated With Milled Polymethyl Methacrylate (PMMA) and Conventional Acrylic Resin: A Prospective Clinical Trial.

Introduction Provisional prosthetic restorations play a crucial role in dentistry by protecting dentinal tubules, offering thermal insulation, and ensuring a precise fit during dental treatments. Computer-aided design and computer-aided manufacturing (CAD/CAM) have improved polymethyl methacrylate (PMMA), enhancing its mechanical properties such as hardness and resistance compared to traditional methods. However, bacterial accumulation remains a challenge due to inherent surface roughness. This study aims to assess and compare Streptococcus mutans adhesion on milled PMMA and conventional self-cure acrylic resin, providing insights into their microbial interaction dynamics. Materials and methods This study was a prospective trial approved by the Institutional Human Ethical Committee (SRB-IHEC) (registration number: IHEC/SDC/PROSTHO-2104/24/045) and registered in the Clinical Trial Registry, India (registration number: CTRI/2024/05/068196). The study involved 20 patients requiring single crowns in the right and left molar regions. Two groups were established: Group I (the milled PMMA group) and Group II (the conventional PMMA group). Criteria for participant selection and exclusion were set. A total of 120 swab samples from the buccal mucosa and tooth surfaces were collected before tooth preparation (the baseline) at one week and three weeks. Culture for S. mutans was done, and colony-forming units were counted. Data analysis was carried out using IBM SPSS Statistics for Windows, Version 26 (Released 2019; IBM Corp., Armonk, New York, United States). An independent sample t-test was employed to compare the two materials for crowns. To analyze changes over time within each group, a repeated-measures analysis of variance (ANOVA) was conducted. When the ANOVA test indicated significance, Tukey's post-hoc test was utilized for pairwise mean comparison. The level of significance was set at P < 0.05. Results The mean colony-forming units (CFU) counts for the milled PMMA group were 4.46 ± 0.167 CFU at baseline, 4.163 ± 0.058 CFU at one week, and 3.87 ± 0.19 CFU at three weeks. The mean CFU counts for the conventional PMMA group were 4.41 ± 0.13 CFU at baseline, 4.29 ± 0.114 CFU at one week, and 4.16 ± 0.108 CFU at three weeks. At baseline (before cementation), there was no difference between milled PMMA and conventional PMMA (P = 0.578). After one week, a significant difference between milled PMMA and conventional PMMA was observed (P < 0.005). After three weeks, a significant difference between milled PMMA and conventional PMMA persisted (P < 0.005). Conclusion There was a significant reduction in microbial adhesion in both the milled and conventional PMMA groups. However, milled PMMA demonstrated a greater decrease in microbial adhesion as compared to conventional PMMA.

Micro- and Macroscopic Analysis of Fatigue Wear of Gear Wheel Top Layer-An Impact Analysis of Thermochemical Treatment.

Today, there are many diagnostic methods and advanced measurement techniques enabling the correct diagnosis and assessment of the type and degree of wear of cogwheels (gears, pumps, etc.). The present study presents an analysis of the surface defects of a cogwheel of an oil pump prototype (3PW-BPF-24). The test object operated for a certain number of hours under controlled operating and environmental parameters. The damage to the surface layer was caused by fatigue phenomena and previous thermo-chemical treatment. On the basis of the significant percentage share (~30%) of residual austenite in the volume of the diffusion layer, a hypothetical conclusion was drawn about the suboptimal parameters of the thermo-chemical treatment process (in relation to the chemical composition of the analyzed pinion). A large number of research studies indicate that the significant presence of residual austenite causes a decrease in tooth surface hardness, the initiation of brittle cracks, a sharp decrease in fatigue strength, an increase in brittleness and a tendency to develop surface layer cracks during operation. High-resolution 3D scans of randomly selected pitting defects were used in the detailed study of the present work. It was indicated that the analysis of the morphology of surface defects allowed some degree of verification of the quality of the heat/chemical treatment. The martensitic transformation of residual austenite under controlled (optimum) repeated heat treatment conditions could significantly improve the durability of the pinion (cogwheel). In the case analyzed, the preferred treatment was the low-temperature treatment. The paper concludes with detailed conclusions based on the microscopic and macroscopic investigations carried out.

"Effect of different Tooth Surface Finish on Marginal Adaptation of Laminate Veneers”-an In Vitro Study

"Effect of different Tooth Surface Finish on Marginal Adaptation of Laminate Veneers”-an In Vitro Study