Diamond Disc Research Articles

Influence of root canal moisture on the penetration of TotalFill bioceramic sealer into the dentinal tubules: A confocal laser scanning microscopy study

Abstract Introduction: Bioceramic (BC) sealers exhibit multiple desirable biologic and physical properties. The aim of this study was to evaluate the effect of root canal moisture on the depth of TotalFill BC sealer penetration into dentinal tubules at different levels using a confocal laser scanning microscope (CLSM). Materials and Methods: The manuscript of this laboratory study has been written according to preferred reporting items for laboratory studies in endodontology 2021 guidelines. Forty single-rooted extracted human premolars were decoronated using a low-speed diamond disc, followed by root canal preparation using nickel–titanium files under copious irrigation. The samples were randomly allocated for obturation into four groups n = 10 based on the sealer and root canal moisture status. Group A: TotalFill BC sealer in wet canal, Group B: TotalFill BC sealer in dry canal, Group C: AH Plus sealer in wet canal, and Group D: AH Plus sealer in dry canal. The roots were sectioned at three different distances from the apex. The root segments were examined using CLSM to measure the extent of sealer penetration into the dentinal tubules. The data underwent analysis through a three-way mixed ANOVA test, followed by post hoc assessments (P < 0.05). Results: In wet canals, the tubular penetration of TotalFill BC sealer was notably greater than that of AH plus, with a statistically significant difference. However, AH Plus sealer had a statistically significant tubular penetration in the dry canals compared to the wet. Greater sealer penetration was observed at 5 mm from the apex, followed by 3 mm, and the least penetration depth was found at 1 mm from the apex. Conclusions: The presence of root canal moisture and distance from the apex had a significant impact on the penetration of TotalFill BC sealer into the dentinal tubules.

An In-Vitro Study to Find the of Frequency of MB2 Canal in Permanent Maxillary Molars

Present in-vitro research conducted to find out the frequency of second mesiobuccal canals in permanent maxillary molars. Eighty extracted, intact maxillary permanent molars were selected for the present study. Following that, a slow-speed diamond disc was used to divide the occlusal sections of the crowns at the cement-enamel junction. Using a safe-end diamond bur, overhanging dentin that covered the canal orifices was removed to allow straight line visibility. Under an x8 magnification, the teeth were photographed from their occlusal side. Result showed that the first and second maxillary molars, MB2 canals were found in 70% and 55%, respectively. In conclusion it is crucial during endodontic procedures on maxillary molars to cautiously check pulpal floor to detect any "extra" canals, notably the second mesiobuccal canal, by scraping away the constrictive dentin above the orifices.

Microleakage of Class II Posterior Composite Restorations with and Without use of Liners - A Comparative Study.

This study aims to compare the effect of liner on microleakage in Class II restorations at the occlusal and gingival levels when restored with a nanocomposite. A total of 60 mandibular molars were selected and divided into three groups. Cavities in Group A were restored with posterior nanocomposite without liner, samples of Group B were restored with posterior nanocomposite with flowable composite liner and in Group C samples were restored with posterior nanocomposite with resin-modified glass ionomer cement (RMGIC) liner. Samples were stored at 37°C in 100% humidity for 14 days. Samples were subsequently immersed in 0.5% methylene blue dye and then placed under water for 15 mins. Teeth were sectioned mesiodistally with a diamond disc and examined under a stereomicroscope. All the cavities exhibited dye penetration along the occlusal and gingival margins of the restored cavities. Group A showed maximum leakage compared to Groups B and C, which was statistically significant ( P = 0.001 and P < 0.0001). No significant difference in microleakage was observed between Groups B and C. Microleakage was more in gingival margins as compared to occlusal margins in all the groups. Based on the results of the present study, it may be concluded that the placement of liner beneath nanocomposite restoration results in a significant reduction in microleakage.

Effect of Various Etching Techniques on Shear Strength of Newer Generation Composites

ABSTRACT Aim: To evaluate the effect of lasers on the shear bond strength of Giomer and G-aenial flo composite using three different etching techniques. Materials and Methods: 60 Samples (extracted human premolar teeth) are cut horizontally using a diamond disk to expose a flat occlusal surface involving enamel and dentin. On exposed occlusal surfaces, etching is done by various methods. These were divided into six groups of ten samples each as follows: group I (acid etched for Giomer), group II (acid etched for G-aenial flo composite), group III (laser etched for Giomer), group IV (Laser etched for G-aenial flo composite), group V (air abrasion etched for Giomer), group VI (Air abrasion etched for G-aenial flo composite). Then, restorative material is placed and cured with light for 20 seconds. The samples were thermocycled to simulate the oral environment. The samples were subjected to a universal testing machine for bond strength testing at a cross-head speed of 3 mm/min until the restoration will fracture. Results: The intergroup comparison between both the materials using Student’s t-test gives insignificant results. The intergroup comparison between different etching techniques using two-way ANOVA tests gives insignificant results. Conclusion: Within the limitation of this study, it can be concluded that Giomer and G-aenial flo composite achieved the same shear bond strength in all the etching techniques.

Bioactivity of Calcium Silicate-Based Endodontic Materials: A Comparative in vitro Evaluation

ABSTRACT Background: Bioactivity refers to the ability of a material to interact with living organisms or biological systems in a way that elicits a specific response. In the context of materials science and medicine, bioactivity is particularly important because it can determine the suitability of material for various applications. Objective: To evaluate and compare different commercially available calcium silicate-based materials regarding: 1. Morphological and elemental analysis at the dentin/material interface. 2. Calcium and silicon release and uptake by adjacent root canal dentine by evaluating the calcium and silicon incorporation depth in adjacent root canal dentin. Materials and Methods: This study examined four calcium silicate-based cements: Biodentine, MTA Angelus, BioAggregate, and MTA Plus. One hundred extracted human teeth with intact apices and no cavities were selected. Root sections measuring 3 mm in length were created at the mid-root level using low-speed diamond discs. Bioactivity was evaluated at 1, 7, 30, and 90 days, respectively. Results: The principal composition of the interfacial dentine layer and incorporation of calcium and silicon into dentine was measured at 1, 7, 30, and 90 days. Statistical analysis was performed by multiple comparisons using post hoc Tukey HSD. Conclusion: All the materials have shown bioactivity, i.e. release of calcium, silicon, and their uptake in the adjacent dentin in the presence of phosphate-buffered saline.

Development of Novel Conditioning Method Using Thermal Shape Memory Characteristics of Polyurethane CMP Pad

Traditionally, the pad roughness has been maintained by wearing down the polyurethane pad with diamond disk. However, that method generates debris and reduces pad lifetime. This study propose a new approach to pad surface recovery by synthesizing a polyurethane-based raw material that exhibits shape memory behavior and can recover its shape upon heating. The findings suggest that the pad’s surface can be maintained by utilizing its shape memory trait and designing a system to heat the pad. The pad recovery tests were conducted using universal test machine (UTM) samples and found that, in terms of heat recovery, increasing the temperature had a greater effect than increasing the exposure time. CMP test was performed by using three conditioning potions: diamond disk conditioning, heat conditioning, and no conditioning. The results showed that pad asperity was recovered more efficiently with heat conditioning than with no conditioning (demonstrated by a 19% higher removal rate). The experimental results can be expected that combines diamond disk conditioning with heat conditioning could be a superior alternative for pad surface refreshment. Shape memory pads can return to their original form, leading to better chemical mechanical planarization (CMP) performance and an extended pad lifetime.

Enhancing the Antibacterial Effect of Erythrosine-Mediated Photodynamic Therapy with Ethylenediamine Tetraacetic Acid

This study evaluated the additive impact of ethylenediamine tetraacetic acid (EDTA) on erythrosine-mediated photodynamic therapy (PDT) against &lt;i&gt;Streptococcus mutans&lt;/i&gt; (&lt;i&gt;S. mutans&lt;/i&gt;) biofilm by measuring colony-forming units and applying confocal laser scanning microscopy. Fifty-six bovine incisors, free from dental caries or structural defects, were utilized in this study. Dentin specimens were created by cutting with a low-speed diamond disk under a continuous flow of water, resulting in dimensions of 6.0 mm × 3.0 mm × 2.0 mm. The specimens were categorized into 4 groups: Control, EDTA, PDT, and EDTA + PDT. &lt;i&gt;S. mutans&lt;/i&gt; ATCC 25175 was employed to establish biofilm on the dentin specimens. A 17% EDTA solution was applied for 1 min. For PDT, erythrosine served as the photosensitizer. Finally, a light-emitting diode source (385 - 515 nm) was employed in this study. The PDT group exhibited a significantly lower bacterial count than both the control and EDTA groups (&lt;i&gt;p&lt;/i&gt; &lt; 0.001). The EDTA + PDT group demonstrated a significantly reduced bacterial count compared to the other 3 groups (&lt;i&gt;p&lt;/i&gt; &lt; 0.001). This study demonstrated that EDTA enhances the antimicrobial efficacy of PDT on S. mutans biofilm. Even at a low concentration of photosensitizer, the combination of EDTA and PDT yields a significant antibacterial effect.

Effect of rock properties on wear and cutting performance of multi blade circular saw with iron based multi-layer diamond segments

This study is an attempt for comprehensive, combining experimental data with advanced analytical techniques and machine learning for a thorough understanding of the factors influencing the wear and cutting performance of multi-blade diamond disc cutters on granite blocks. A series of sawing experiments were performed to evaluate the wear and cutting performance of multi blade diamond disc cutters with varying diameters in the processing of large-sized granite blocks. The multi-layer diamond segments comprising the Iron (Fe) based metal matrix were brazed on the sawing blades. The segment’s wear was studied through micrographs and data obtained from the Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray (EDS). Granite rock samples of nine varieties were tested in the laboratory to determine the quantitative rock parameters. The contribution of individual rock parameters and their combined effects on wear and cutting performance of multi blade saw were correlated using statistical machine learning methods. Moreover, predictive models were developed to estimate the wear and cutting rate based on the most significant rock properties. The point load strength index, uniaxial compressive strength, and deformability, Cerchar abrasivity index, and Cerchar hardness index were found to be the significant variables affecting the sawing performance.

Analysis of the depth of penetration of an epoxy resin-based sealer following a final rinse of irrigants and use of activation systems: An in vitro study.

The objective of the study was to compare and evaluate the depth of penetration of an epoxy resin-based sealer following a final rinse of 17% ethylenediaminetetraacetic acid (EDTA) and 18% 1-hydroxyethylidene 1, 1-diphosphonate (HEDP), with diode laser and passive ultrasonic activation (PUI): an in vitro confocal laser scanning microscopy study. Fifty-two extracted human mandibular premolar teeth with single root and single canal were selected. They were disinfected in 0.1% thymol solution, cleaned of calculus and soft tissues, and stored in 0.1% thymol solution till use. All teeth were radiographed and selected as per the inclusion and exclusion criteria. The teeth were decoronated using a diamond disk under copious water spray to acquire a standardized root length of 14 mm. Working length was established by inserting a size 10-K file into each root canal until it is visible at the apical foramen and by subtracting 1 mm from the recorded length. Instrumentation of the root canal was done till master apical file size of F3 using ProTaper universal, rotary instruments. The canals were irrigated with 2 mL of 3% sodium hypochlorite between successive files. Teeth were randomly divided into four subgroups n = 12 according to the intervention. Passive ultrasonic irrigation and diode laser were used to activate the irrigants. Final irrigation was performed with distilled water. These specimens were examined using confocal laser scanning microscope (OLYMPUS FLUOVIEW FV 3000) for dentinal tubule penetration of the sealer. Two-way ANOVA test and Tukey's multiple post hoc test were used for statistical analysis. Highly significant difference was seen between the groups with EDTA and HEDP, with HEDP demonstrating the highest penetration. Among the activation techniques used in this study, PUI showed the highest penetration of the sealer. The least penetration was seen with diode laser activation and EDTA. The irrigation activation techniques significantly influence the penetration of sealer into root dentinal tubules. When penetration of sealer with different irrigation techniques and irrigants was evaluated, significant greater level of sealer penetration was attained with PUI activation of HEDP.

Evaluation of apically extruded debris using protaper universal, protaper next, one curve, Xp shaper, and edge file: An in vitro study

Introduction: Effective chemo-mechanical debridement is essential for a successful endodontic treatment. The present study aimed to determine the quantity of apical extruded debris during instrumentation by Protaper Universal (PTU), Protaper Next (PTN), One Curve, Xp Shaper, and Edge file systems. Materials and Methods: Fifty human maxillary first molars were chosen for this study. The palatal roots of teeth were decoronated using a diamond disk at length 13 mm, Then 50 samples were randomly divided to five groups (n = 10) (Group I: PTU file; Group II: PTN file; Group III: One Curve file; Group IV: XP Shaper file; and Group V: Edge file). After instrumentation, the root-cap assembly was detached from the glass vial. After that, the outer surface of the root was rinsed in the vial by 2 mL of normal saline to eliminate any debris that could have attached to it. The samples’ vials were stored in a hot air oven for 2 h at 100°C to allow moisture to evaporate before the debris was weighed with an electronic balance that had a 0.0001 g precision. Results: The data were statistically analyzed, and the greatest amount of extruded debris was in the PTU file (mean = 1.596), which had a statistically significant difference (P &lt; 0.05) with all other groups. Conclusion: Even after taking the study’s limitations into account, apical debris extrusion was observed in all groups. In contrast to the PTU file system, which exhibited the greatest value, the One Curve file system showed the lowest mean value of apical extrusion debris.

Comparative Analysis of Photosensitizer Penetration Depth in Root Canal Debridement for Endodontic Disinfection.

Microbial agents play a crucial role in periapical lesions and despite mechanical preparation, presence of persistent bacteria in root canal system is a challenge. Photodynamic therapy offers a debridement method, utilizing photosensitizers such as Curcumin, Indocyanine Green (ICG), and Methylene Blue (MB). This study aimed to assess and compare the penetration depth of these photosensitizers on the lateral surface of the root canal. The crown of 30 single-rooted teeth were separated by a diamond disc. The canals were prepared using a rotary system and were rinsed with 10 mL of 2.5% NaOCl. In order to remove the smear layer debris, 17% EDTA was placed in the root canal for 1 min, then rinsed with NaOCl and saline. The teeth were sterilized by autoclave and randomly assigned to three groups that filled with curcumin, ICG, or MB. Subsequently, they were incubated for 10 min and dried up by paper. Longitudinal sections were cut, and penetration depth of the photosensitizers in coronal, middle, and apical sections were measured using a stereomicroscope. Curcumin demonstrated a higher average penetration depth (3000 µm) than MB, and MB showed higher penetration depth than ICG. Significantly different penetration depths were observed in pairwise comparisons among all three groups (P<0.005). Curcumin with its superior average penetration depth, emerges as a promising choice for effective root canal disinfection in endodontic treatments. Consideration of these findings may enhance the selection of photosensitizers in clinical applications.

Effects of titanium (Ti) contents on the wear resistance of low-alloy steel alloys

In this study, the impact of titanium (Ti) on low-alloy steel alloys is examined, focusing on the mechanical properties of the alloy with varying Ti content levels. Heat treatment was conducted to enhance the mechanical properties and performance indicators of the casting samples. The elemental volume distribution mapping and microstructure analysis of the research samples were performed using SEM - Carl Zeiss Ultra Plus Field Emission. Subsequently, the hardness and wear resistance characteristics of samples containing Ti contents of 0, 0.1, 0.3, 0.5, 0.8, and 1.1 were evaluated post heat treatment. Notably, steel samples containing 0.3% and 0.5% Ti, exhibiting structures of ferrite, martensite, and limited bainite, demonstrated superior hardness and wear resistance properties. Abrasive wear resistance tests were conducted using a specialized device with a horizontal diamond disc. The primary objective of this research is to introduce the developed technology for the rolling mill rolls at a prominent metal manufacturing enterprise in the republic, resulting in enhanced economic efficiency through increased production volume. Consequently, achieving a hardness of HB 323 and improving wear resistance by 1.2 times were notable outcomes of the study.

An in vitro evaluation of dentinal microcrack formation during root canal preparations by three different nickel–titanium systems: ProTaper Gold, HyFlex CM, and Silk

Aim: This study aimed to compare the frequency of dentinal microcracks after root canal shaping with three different nickel–titanium (NiTi) systems, namely, ProTaper Gold (PG), HyFlex CM (HCM), and Silk. Methods: One hundred mandibular premolars with a single canal were chosen for this study. All specimens were decoronated and divided into four groups of 25 each. Teeth were mounted in the acrylic block with simulated periodontal ligaments. Group I served as a negative control Group, in which no treatment was performed. Biomechanical preparation was done in the Group II, using the Protaper gold file system. Group III, using the Hyflex CM file system and Group IV, using the Silk file system. Specimens were horizontally sectioned at 3, 6, and 9 mm from the apex using the low-speed diamond disc under water cooling. The slices were then viewed under a stereomicroscope at ×25 to determine the presence of cracks. The absence or presence of cracks was recorded, and the data were analyzed with a Chi-square test. The significance level was set at P &lt; 0.05. Results: Coronal section showed lesser crack formation in all three groups after biomechanical preparation. More number of dentinal microcracks were seen in the apical sections, followed by the middle and the coronal sections in Group II (PG), followed by Group IV (Silk), and Group III (HCM), respectively. Group II showed more microcracks at all three levels of the root canals when compared with Groups III and IV. Intergroup analysis showed no statistically significant difference in microcrack formation. Conclusion: Within the limitation of this in vitro study, it can be concluded that NiTi instruments may cause cracks on the root surface. HCM and Silk files tend to produce a less number of cracks as compared to PG instruments.

Comparative Analysis of Marginal Adaptation of Different Root Canal Sealers Using Scanning Electron Microscope

Aims:The present study aimed to evaluate and examine the degree of marginal adaptation of several root canal sealers using a scanning electron microscope (AH Plus, MTA-Fillapex, Total-Fill, and GuttaFlow Bioseal) to root dentine.&#x0D; Methods and Material:Forty extracted mandibular premolars with completely formed apices and a single root were selected. The root canals were instrumented after the decoronation of teeth. The samples (n = 10) were divided randomly into four groups. Group (1) was sealed with a resin-based sealer (AH Plus), Group (2) with an MTA-based sealer (MTA-Fillapex), Group (3) with a bioceramic sealer (TotalFill BC), and Group (4) with a silicone-based sealer (GuttaFlow Bioseal). After horizontally slicing samples with a diamond disk, marginal adaptability was evaluated using SEM.&#x0D; One-way ANOVA test and the multiple Post hoc test of Tukey was reliant on the statistical analysis of the data.&#x0D; Results: TotalFill BC has shown significantly higher marginal adaptation than MTA-Fillapex and GuttaFlow Bioseal (P &lt; 0.05). There is no significant difference between apical and coronal sections in the four tested groups under SEM (P &lt; 0.05).&#x0D; Conclusions: Total fill BC outperformed the other tested sealers in terms of marginal adaptability.

Evaluation of Modified Shell Technique in 3D Ridge Reconstruction: A Clinical and Radiographic Study

Introduction: As a result of tooth loss, alveolar ridge resorption sacrifices bone volume including bone width. In order to replace the lost dentition with implants functionally and esthetically, bone augmentation procedures are carried out. Materials and Methods: Fifteen patients were selected to treat mandibular alveolar ridge resorption with an autogenous block graft harvested using piezoelectric surgical tips and split into two shells using a diamond disk then fixated on the decorticated defective ridge. Particulate xenograft bovine bone was then inserted between the fixated shell and ridge, the second shell was used to roof the bone particles. Results: The modified shell technique could be an alternative to other ridge augmentation techniques. This study shows promising clinical and radiographic results that carry the advantages of being: safe and precise cutting using Piezoelectric tips, the statistical data showed a significant difference in 3D bone volume where no unfavorable complication was detected. Conclusion: The modified shell technique showed a reliable technique in cases of 3D ridge reconstruction since it holds the advantages of autogenous bone properties and the rigidity of the bone shells that maintain the space necessary for augmentation. The use of PRF can accelerate wound healing and minimize the risk of flap dehiscence as well as it can speed up bone formation.

Impact of Various Desensitizing Agents on the Micro-Tensile Bond Strength of Adhesive Systems: &lt;i&gt;In-Vitro&lt;/i&gt; Study

Objectives: To assess the influence of various desensitizing agents on the micro-tensile bond strength of various adhesive systems. Methods: Fifty extracted human permanent third molars, were sectioned at the cementoenamel junction in order to expose the mid-coronal dentinal tubules in parallel to the occlusal surface using a diamond disc and water coolant. The samples were divided into five groups and each sample was immersed in the respective desensitizing agent (Groups 1 to 5; Group 1- Distilled water, Group 2- Arginine calcium carbonate (Sensitive Pro-Relief Colgate- Palmolive, India, Group 3- Calcium sodium phosphosilicate (Repair and Protect, GlaxoSmithKline, India), Group 4- Strontium chloride hexahydrate 10% w/w (ICPA Health Products Ltd, India.), Group 5- Er,Cr: YSGG (Waterlase MD, Biolase, Irvine, CA, USA) with each group having a sample of n = 10. Each group was further divided into two subgroups (n = 5) based on the adhesive system (either a One-step self-etch adhesive (Xeno v+) (SE) or a two-step etch and rinse adhesive (Prime and Bond NT) (EandR)). Instron Micro tensile Tester was used to analyze the Micro-Tensile Bond Strength (MTBS) of the samples. Results: The bond strength of the control group (Group 1) was greater as compared to the other four groups, though statistically insignificant. There was a significant difference in the bond strength of the two subgroups (p&lt;0.001) One-step self-etch adhesive (SE, Xeno V+) and two-step etch and rinse adhesive (EandR; Prime and Bond NT) adhesive. Conclusion: The use of desensitizing agents does not affect the micro tensile bond strength of adhesives used for the management of restoration of Non-Cervical Carious Lesions (NCCL). Microtensile bond strength with a self-etch adhesive system was significantly lower in the desensitized dentin irrespective of the agents used.

Comparative evaluation of antimicrobial efficacy of different combinations of calcium hydroxide against Enterococcus faecalis

BackgroundThe study aims to compare the synergistic antibacterial efficacy of different combinations of calcium hydroxide as an intracanal medicament against E. faecalis.Material and methodsThe current study included four hundred extracted human permanent mandibular premolar teeth. After complete chemo-mechanical preparation, the middle third of the root was sectioned using a rotary diamond disc and a total of 400 samples were obtained. The specimens were inoculated with E. faecalis for 21 days. After that, specimens were divided into five groups (n = 80) based on materials used for the disinfection of samples: Group I, calcium hydroxide alone; Group II, calcium hydroxide + 2% chlorhexidine gel; Group III, calcium hydroxide + 2% chitosan gel; Group IV, calcium hydroxide + 0.02% silver nanoparticle gel; Group V, calcium hydroxide + Bioactive glass S53P4. Dentin shavings from the apical third were obtained from the inner third of dentin were obtained using gates glidden no.1 to the apical depth, followed by no.2, 3, 4 and 5 analyzed for E. faecalis using the culture method. One-way analysis of variance (ANOVA) was used for data analysis, followed by post-hoc Tukey's test for multiple comparisons of means to check the difference in bacterial inhibition between the groups.ResultsANOVA results revealed a significant reduction of bacterial counts in all the groups compared (p < 0.001). Intergroup comparison showed maximum bacterial reduction (p < 0.001) with calcium hydroxide + bioactive glass S53P4 compared with other groups.ConclusionSynergistic effect of calcium hydroxide showed better bacterial reduction compared to calcium hydroxide alone. Among the combinations evaluated, calcium hydroxide with bioactive glass, found to be most effective compared to other groups.

Impact of Heating Exposure on the Micro-Push-Out Bond Strength of Bioceramic Sealers

Introduction. The aim of this study was to evaluate the effect of heating of bioceramic and epoxy resin-based sealers on their micro-push-out bond strength (BS) to root canal dentin. Methods. After criterial selection, 30 human teeth were decoronated and 1-mm thick slices (n = 60) were obtained perpendicularly along tooth axis, from cervical and middle root thirds, with a diamond disc attached to a cutting machine. In each slice, three 1.0-mm diameter orifices were made. After rinsing with 17% EDTA and 2.5% NaOCl, each orifice was filled with Bio-C Sealer or BioRoot RCS or AH Plus, according to the manufacturers’ instructions. After filling, half of the slices (n = 30) were heated at 100°C for 1 min, and the other half were kept at room temperature. After 7 days-controlled storage, micro-push-out test was performed in a Universal Testing Machine. Failures were analyzed using a stereomicroscope. Statistical analysis was performed with One-Way ANOVA and post hoc Tukey (α = 5%) tests. Results. AH Plus demonstrated higher BS values after heating ( p = 0.001 ) when compared to nonheated. The other sealers did not show a statistically significant difference ( p &gt; 0.05 ). When heated, the average BS values for AH Plus were higher than for BioRoot RCS and Bio-C Sealer ( p &lt; 0.001 ). Cohesive failure mode was the most frequent, followed by adhesive and mixed ones. Conclusion. Heating provided a higher push-out BS to root dentin for AH Plus and did not influence BioRoot RCS or Bio-C sealer.

A comparative evaluation of the effect of alcoholic and non alcoholic beverages on tooth enamel surface pretreated with β-tricalcium phosphate, bioactive glass and amine fluoride: an in vitro study

Background and aims. The aim of this in vitro study is to quantitatively evaluate the effect of different alcoholic and non alcoholic beverages on the tooth enamel surface topography pretreated with various remineralizing agents using Atomic Force Microscopy.&#x0D; Methods. 120 tooth specimens were prepared from 60 freshly extracted intact human premolars by sectioning from mesial to distal surfaces using low speed diamond discs and were randomly assigned to study groups and control group. Specimens of Group I, Group II and Group III were pre-treated with β-Tri calcium phosphate, bioactive glass and amine fluoride respectively for 4 minutes for 28 days, followed by storage in artificial saliva. All the specimens were evaluated for surface roughness using Atomic Force Microscopy. The specimens were then placed in alcoholic and non-alcoholic beverages for 10 minutes for 4 days and were again analyzed by Atomic Force Microscopy.&#x0D; Descriptive statistics was performed by using the proportional or frequency distribution of the parameters. The respondents were then grouped according to the branch of specialty if any and the data was evaluated by the one-way ANOVA with post-hoc, with p value &lt;0.005.&#x0D; Results. In the present study, among the remineralizing agents tested, bioactive glass was found to be more effective than β-Tri Calcium Phosphate and Amine Fluoride. Among the demineralizing agents used in this study, the demineralization potential of Coca Cola was found to be highest, followed by wine and green tea pretreated with β -tricalcium phosphate, bioactive glass and amine fluoride.&#x0D; Conclusions. The present study concluded that all the remineralizing agents tested were found to be effective in inhibiting the demineralization caused by various alcoholic and non alcoholic beverages. Among the remineralizing agents tested, bioactive glass was found to be more effective than β-tri calcium phosphate and amine fluoride.

EKONT-2: advancement of a demonstrator for dry–mechanical decontamination of corners and inner edges in nuclear facilities

Abstract. In order to be able to dismantle nuclear power plants after decommissioning, all surfaces must be decontaminated before conventional demolition. Difficulties in decontamination are not caused by large and easily accessible areas but rather by the corners and inner edges that are difficult to access and cannot be reached with existing machines. In order to be able to decontaminate these areas, however, hand-held tools are currently being used that were developed for conventional dismantling and building renovation. In order to ensure occupational safety and to prevent the spread of contamination, these devices must be used with an external suction system. The area coverage that is already low is thus further reduced, and hard-to-reach areas are even more difficult to reach. These factors and working in protective suits make these decontamination tasks a great challenge for the workers carrying out the work. The EKONT-2 research project was launched to make this work easier and more efficient. This project, which is funded by the Federal Ministry of Education and Research (BMBF), has set itself the goal of developing an innovative, partially automated demonstrator for dry-mechanical decontamination of corners, edges and imperfections in nuclear facilities. For this purpose, different active principles have already been examined, evaluated according to scientific methods and implemented in the form of four test models. One of the test models enables material removal with high-frequency vibrations and a diamond-coated tool. The other three demonstrators remove the material with rotating diamond discs and rotate in different directions depending on the design. To realise the different directions of rotation, one of the demonstrators is equipped with a newly developed gear, for which a patent application has already been submitted. Before the devices could go into practical testing, various performance parameters were recorded and evaluated in a test stand specially developed for this purpose. In addition, the reliability of the devices could already be tested, and any problems that arose could be rectified. After this detailed test of the devices in the test stand, the test samples could be checked for their practical suitability in the Obrigheim nuclear power plant. Here, workers at SAT Kerntechnik GmbH tested the devices in a real environment and were able to give mostly positive feedback on the developed demonstrators. In addition, the feedback has revealed potential for improvement that is to be pursued and implemented in a subsequent project.