scholarly journals Effect of Sterilization (Autoclave) on Wear of Tungsten-Carbide Burs Coated With Diamond Particles With Different Thicknesses

2021 ◽  
Vol 13 (4) ◽  
pp. 119-123
Author(s):  
Zahra Khamverdi ◽  
Ebrahim Yarmohammadi ◽  
Behzad Tolaminejad ◽  
Anahita Barghilashgari
Keyword(s):  
Standard Deviation ◽  
Tungsten Carbide ◽  
In Vitro Study ◽  
Plasma Coating ◽  
Dental Instruments ◽  
Diamond Particles ◽  
Study Results ◽  
Significant Difference ◽  
Dental Burs

Background: Extending the lifespan and improving the physical properties of dental burs as the most extensivly used instruments have been the subject of several studies. One of the proposed methods is using surface coatings for the burs. Since the dental instruments are reused, they require sterilization. One of the possible causes of the damage to dental burs is autoclaving process. This study aimed to investigate sterilization (autoclave) effect on wear of diamond coated tungsten-carbide burs with different thicknesses. Methods: In this in vitro study, 40 tungsten-carbide dental burs (IQ DENT, Poznan, Poland) were selected, out of which 20 burs were coated with 1.5-μm-like diamond particles, and 20 burs were coated with 3.5-μm by PVD method using Swin Plasma Coating Machine. Then, the burs were randomly divided into four groups (n=10) as follow: G1: 1.5 μm thickness coated burs without sterilization; G2: 3.5 μm thickness coated burs without sterilization; G3: 1.5 μm coated with sterilization; and G4: 3.5μm thickness coated burs with sterilization. Their weights were measured before wear test.Wear test was performed and then they were re-weighted. Data were analyzed using SPSS software (version 21) as well as Two-way ANOVA and Tukey HSD supplementary tests (α=0.05). Results: Mean and standard deviation of the burs weights without sterilization in the control groups were 7.31±2.63 and 7.96±1.61 mg, respectively; and mean and standard deviation of the burs weights in the sterilization groups were 7.06±0.98 and 7.12±1.11 mg, respectively. The study results showed that "sterilization application" and "thickness of coated layer" were the main factors and their intraction had no statistically significant difference (P=0.589). Conclusions: The sterilization process had no effect on wear of diamond coated tungsten-carbide burs with different thicknesses.

scholarly journals Evaluation of sealing between abutment and inner connection of cone morse dental implant

2018 ◽  
Author(s):  
Derivaldo Moura Gois Filho ◽  
Vanessa Tavares de Gois-Santos ◽  
Ronaldo Santos Silva ◽  
Antônio Carlos Marqueti ◽  
Arthur Rodriguez Gonzalez Cortes ◽  
...  
Keyword(s):  
Dental Implants ◽  
Treatment Success ◽  
In Vitro Study ◽  
Study Results ◽  
Significant Difference ◽  
Group 2 ◽  
Dental Abutments ◽  
Scanning Electron ◽  
Group 1

Introduction: The adaptation of prostheses fixed over implants involves biomechanical aspects that are directly associated with treatment success. Objective: The aim of this in vitro study was to evaluate the presence of microgaps in the abutment/inner connection interface of cone morse dental implants. Materials and methods: Two groups of implants were analyzed. The first group (n = 16) employed single-manufacturer dental implants and abutments, whereas the second group (n = 16) combined multi-manufacturer materials. The sets were analyzed through scanning electron mi­croscopy, wherein microgaps between the implant connection and the abutment were observed. Results: Group 1 had an average microgap of 5.69 μm (SD ± 8.46 μm). Group 2 had an average microgap of 1.24 μm (SD ± 0.44 μm). A significant difference was found between the two groups (p = 0.002). Conclusion: Within the limitations of this study, results suggest that the group formed by multi-manufacturer implants and abutments (group 2) had smaller microgap values, and, therefore, a higher in vitro adaptation of components. DESCRIPTORS | Dental Implants; Dental Abutments; Scanning Electron Microscopy.

Comparison of Fracture Strengths among different Commonly Placed Anterior Esthetic Restorations for Primary Dentition: An in vitro study

2021 ◽  
Vol 45 (3) ◽  
pp. 171-176
Author(s):  
Brent Lin ◽  
Amit Khatri ◽  
Michael Hong
Keyword(s):  
Fracture Strength ◽  
Testing Machine ◽  
In Vitro Study ◽  
Vitro Study ◽  
Anterior Teeth ◽  
Study Results ◽  
Luting Cement ◽  
Significant Difference ◽  
All Ceramic

The purpose of this study was to determine and compare the shear force (N) required to fracture or dislodge an all-ceramic zirconia-based crown using different luting cement with those of polycarbonate crown and strip crown for the primary anterior teeth in vitro. Study design: Four groups of esthetic restoration for primary anterior teeth were tested for fracture strength: 1) Fifteen all-ceramic zirconia-based crowns cemented with glass ionomer cement, 2) Fifteen all-ceramic zirconia-based crowns bonded with a self-adhesive resin cement, 3) Fifteen polycarbonate crowns cemented with a polymer reinforced zinc-oxide eugenol and 4) Fifteen resin strip crowns. All restorations were placed and cemented on reproductions of dies in an independent laboratory at Delhi, India. All samples underwent loading until fracture or dislodgement with the Universal Testing Machine. The force in Newton (N) required to produce failure was recorded for each sample and the type of failures was also noted and characterized. One-way analysis of variance (ANOVA) test and the Tukey and Scheffe’s post hoc comparisons were used for statistical analyses. Results: In this invitro study, results were measured in Newtons (N). Group 1 (410.9±79.5 N) and Group 2 (420.5±57.8 N) had higher fracture strength than Group 3 (330.3±85.6 N) and Group 4 (268.4±28.2 N). These differences were statistically significant at P≤.05 among the sample groups. No significant difference was found between groups 1 and 2 (P = 0.984) nor between groups 3 and 4 (P =0.104). Among type of failures, majority of restoration fractures for zirconia-based crowns and resin strip crowns were due to cohesive failures and polycarbonate crowns had predominantly mixed failures. Conclusions: Under the limitations of this in vitro study, it could be concluded that all-ceramic zirconia-based crowns attained the highest fracture strength among all restorative samples tested regardless of the type of luting agent employed (P<.01). Cohesive failures were commonly observed in the zirconia crowns and resin strip crowns, whereas polycarbonate crowns revealed predominately mixed failures.

scholarly journals Evaluation of Enamel Surface after Removal of Adhesive Resin: An in Vitro Study

2018 ◽  
Vol 8 (2) ◽  
pp. 12-16
Author(s):  
Geeta Pyakurel ◽  
Gazi Shamim Hassan ◽  
Mahmood Sajedeen
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Tungsten Carbide ◽  
In Vitro Study ◽  
T Test ◽  
Enamel Surface ◽  
Adhesive Resin ◽  
Significant Difference ◽  
And Tungsten

Introduction: Preservation of the enamel surface during the removal of orthodontic appliance is an essential aspect for clinicians. However, various therapeutic measures can affect the enamel surface. The objective of the research is to evaluate the roughness of enamel surface after the removal of adhesive resin. Materials & Method: 40 extracted human premolar teeth were randomly divided into two groups and the enamel surfaces were initially subjected to profilometer for the assessment of surface roughness. Following bracket bonding, debonding was done and adhesive resin was removed by stainless steel bur in Group A and tungsten carbide bur in Group B. Again, the surface roughness was measured by profilometer. Independent t-test was performed to compare the enamel surface roughness between two groups and paired t-test to compare the enamel surface roughness within the groups. Result: The mean average surface roughness of stainless steel bur was 27.009 ± 4.8420 μm and tungsten carbide was 31.426 ± 5.0956 μm. The result showed that there was significant difference in enamel surface roughness between two groups. Conclusion: The roughness values were found to be significantly decreased with the use of stainless steel bur (SS) than tungsten carbide bur (TC).

scholarly journals Influence of Intra-Oral Scanner (I.O.S.) on The Marginal Accuracy of CAD/CAM Single Crowns

2019 ◽  
Vol 16 (4) ◽  
pp. 544 ◽  
Author(s):  
Francesco Ferrini ◽  
Gianpaolo Sannino ◽  
Carlo Chiola ◽  
Paolo Capparé ◽  
Giorgio Gastaldi ◽  
...  
Keyword(s):  
Standard Deviation ◽  
In Vitro Study ◽  
Mean Value ◽  
Vitro Study ◽  
Computer Assisted ◽  
Marginal Gap ◽  
Significant Difference ◽  
Cad Cam ◽  
True Definition

The aim of this in vitro study was to compare the quality of digital workflows generated by different scanners (Intra-oral digital scanners (I.O.S.s)) focusing on marginal fit analysis. A customized chrome-cobalt (Cr-Co) implant abutment simulating a maxillary right first molar was fixed in hemi-maxillary stone model and scanned by eight different I.O.S.s: Omnicam® (Denstply Sirona, Verona, Italy) CS3500®, CS3600®, (Carestream Dental, Atlanta, GA, USA), True Definition Scanner® (3M, St. Paul, MN, USA), DWIO® (Dental Wings, Montreal, Quebec, Canada), PlanScan® (Planmeca Oy, Helsinki, Finland), 3D PROGRESS Plus® (MHT, Verona, Italy), TRIOS 3® (3Shape, Copenhagen, Denmark). Nine scans were performed by each tested I.O.S. and 72 copings were designed using a dental computer-assisted-design/computer-assisted-manufacturing (CAD/CAM) software (exocad GmbH, Darmstadt, Germany). According to CAD data, zirconium dioxide (ZrO2) copings were digitally milled (Roland DWX-50, Irvine, CA, USA). Scanning electron microscope (SEM) direct vision allowed for marginal gap measurements in eight points for each specimen. Descriptive analysis was performed using mean, standard deviation, and median, while the Kruskal–Wallis test was performed to determine whether the marginal discrepancies were significantly different between each group (significance level p < 0.05). The overall mean marginal gap value and standard deviation were 53.45 ± 30.52 μm. The minimum mean value (40.04 ± 18.90 μm) was recorded by PlanScan®, then 3D PROGRESS Plus® (40.20 ± 21.91 μm), True Definition Scanner® (40.82 ± 26.19 μm), CS3500® (54.82 ± 28.86 μm) CS3600® (59,67 ± 28.72 μm), Omnicam® (61.57 ± 38.59 μm), DWIO® (62.49 ± 31.54 μm), while the maximum mean value (67.95 ± 30.41 μm) was recorded by TRIOS 3®. The Kruskal–Wallis tests revealed a statistically significant difference (p-value < 0.5) in the mean marginal gaps between copings produced by 3D PROGRESS Plus®, PlanScan, True Definition Scanner, and the other evaluated I.O.S.s. The use of an I.O.S. for digital impressions may be a viable alternative to analog techniques. Although in this in vitro study PlanScan®, 3D PROGRESS Plus® and True Definition Scanner® may have showed the best performances, all I.O.S.s tested could provide clinically encouraging results especially in terms of marginal accuracy, since mean marginal gap values were all within the clinically acceptable threshold of 120 μm.

Antimicrobial Activity of Glass Ionomer Cements with Chlorhexidine and Propolis: An In Vitro Study

2019 ◽  
Vol 14 (04) ◽  
pp. 168-170
Author(s):  
Makbule Tugba Tuncdemir ◽  
Ayşe Ruveyda Ugur ◽  
Bilgen Ozdemir
Keyword(s):  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
Inhibition Zone ◽  
Glass Ionomer ◽  
Study Results ◽  
Significant Difference ◽  
Restorative Materials ◽  
Mueller Hinton Agar ◽  
Liquid Preparation

AbstractThe aim of this study was to evaluate the antibacterial effect of conventional glass ionomer cement with the addition of antibacterial constituents in its liquid preparation. Two groups of glass ionomers prepared with propolis and chlorhexidine and a third group without any additive used as control were sterilized by low-temperature hydrogen peroxide plasma sterilizer at the sterilization unit. Seven to eight disk-shaped restorative materials of each group were placed on the Mueller Hinton Agar with sheep blood 5% v/v, on which Streptococcus mutans inoculated. The plates were incubated at 37°C in 5% CO2 for 24 to 48 hours. After 24-hour and 48-hour-incubation, inhibition zone diameters of each restorative materials were measured. No distinct inhibition zone was reported; only a slight zone (6 mm) around the contact surfaces of each material was observed after the 24-hour and 48-hour incubations. No significant difference was observed in the inhibition zone diameters between the two test groups and control. Within the limitations of this study, results revealed that there was no antibacterial difference among glass ionomers prepared with propolis and chlorhexidine.

Comparative Study to Evaluate the Surface Detail Reproduction of Dental Stone after Immersion in Various Different Disinfectant Solutions, Under Stereomicroscope 10 X Magnification –An In-Vitro Study

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
Rathika Rai ◽  
M. A. Easwaran ◽  
K. T. Dhivya
Keyword(s):  
Sodium Hypochlorite ◽  
In Vitro Study ◽  
Control Group ◽  
Immersion Method ◽  
Significant Difference ◽  
Surface Irregularities ◽  
Disinfectant Solution ◽  
Surface Detail ◽  
Group B

Aim: To evaluate the surface detail reproduction of dental stone this is immersed in different disinfectant solution and studied under stereomicroscope. Methodology: Total number of 30 specimens of dental stone (Type III) were made with measurements of 1.5cm diameter and 1cm height .This samples are divided in to 3 groups group A,B,C. were A is immersed in Distilled water which was taken as control group ;B is immersed in 2% Glutaraldehyde and C is immersed in 5%sodium hypochlorite. Each specimen were immersed in the disinfectant solution for 15 minutes and dried under room temperature for 24 hrs. After 24 hrs each specimens are studied under stereomicroscope for surface details. Result: The results showed no significant difference in the surface irregularities and porosities for a group 1 and group 2 except group 3 which showed significant increase in the porosities, surface irregularities and erosions after disinfection with 5% NaHOCl by immersion method. Conclusion: The surface detail reproduction capacity of die stone was adversely affected when 5% Sodium hypochlorite was used as disinfectant solution when compare d to control group and 2% Glutaraldehyde

scholarly journals Marginal and Internal Fit of Ceramic Prostheses Fabricated from Different Chairside CAD/CAM Systems: An In Vitro Study

2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee
Keyword(s):  
Computer Aided Design ◽  
In Vitro Study ◽  
Vitro Study ◽  
Marginal Gap ◽  
Significant Difference ◽  
Cad Cam ◽  
Ceramic Crowns ◽  
Internal Fit ◽  
Cam Systems

The purpose of this in vitro study was to evaluate marginal and internal fits of ceramic crowns fabricated with chairside computer-aided design and manufacturing (CAD/CAM) systems. An experimental model based on ISO 12836:2015 was digitally scanned with different intraoral scanners (Omnicam (CEREC), EZIS PO (DDS), and CS3500 (Carestream)). Ceramic crowns were fabricated using the CAD/CAM process recommended by each system (CEREC, EZIS, and Carestream systems; N = 15). The 3-dimensional (3D) marginal and internal fit of each ceramic crown was measured using a 3D inspection software (Geomagic control X). Differences among the systems and various measurements were evaluated using the Kruskal–Wallis test. Statistically significant differences were validated using pairwise comparisons (α = 0.05). Occlusal gaps in the CEREC, EZIS, and Carestream groups were 113.0, 161.3, and 438.2 µm, respectively (p < 0.001). The axial gaps were 83.4, 78.0, and 107.9 µm, respectively. The marginal gaps were 77.8, 99.3, and 60.6 µm, respectively, and the whole gaps were 85.9, 107.3, and 214.0 µm, respectively. Significant differences were observed with the EZIS system compared with the other two systems in terms of the marginal gap sizes. The CEREC system showed no significant differences among the four measured regions. However, the EZIS and Carestream systems did show a statistically significant difference (p < 0.05). All three systems were judged to be capable of fabricating clinically acceptable prostheses, because the marginal gap, which is the most important factor in the marginal fit of prostheses, was recorded to be below 100 µm in all three systems.

Assessment of mechanical and biocompatible performance of ultra-large nitinol endovascular devices fabricated via a low-energy laser joining process

2021 ◽  
pp. 088532822110195
Author(s):  
Moataz Elsisy ◽  
Mahdis Shayan ◽  
Yanfei Chen ◽  
Bryan W Tillman ◽  
Catherine Go ◽  
...  
Keyword(s):  
Laser Power ◽  
In Vitro Study ◽  
Spot Size ◽  
Laser Joining ◽  
Study Results ◽  
Energy Laser ◽  
Joining Process ◽  
Endovascular Devices ◽  
Low Energy Laser

Nitinol is an excellent candidate material for developing various self-expanding endovascular devices due to its unique properties such as superelasticity, biocompatibility and shape memory effect. A low-energy laser joining technique suggests a high potential to create various large diameter Nitinol endovascular devices that contain complex geometries. The primary purpose of the study is to investigate the effects of laser joining process parameters with regard to the mechanical and biocompatible performance of Nitinol stents. Both the chemical composition and the microstructure of the laser-welded joints were evaluated using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). In vitro study results on cytotoxicity demonstrated that the joining condition of 8 Hz frequency and 1 kW laser power showed the highest degree of endothelial cell viability after thermal annealing in 500°C for 30 min. Also, in vitro study results showed the highest oxygen content at 0.9 kW laser power, 8 Hz frequency, and 0.3 mm spot size after the thermal annealing. Mechanical performance test results showed that the optimal condition for the highest disconnecting force was found at 1 Hz frequency and 1 kW power with 0.6 mm spot size. Two new endovascular devices have been fabricated using the optimized laser joining parameters, which have demonstrated successful device delivery and retrieval, as well as acute biocompatibility.

scholarly journals In vitro study of human osteoblast proliferation and morphology on orthodontic mini-implants

2015 ◽  
Vol 85 (6) ◽  
pp. 920-926 ◽  
Author(s):  
Ricardo Carvalho Bueno ◽  
Roberta Tarkany Basting
Keyword(s):  
Chemical Composition ◽  
In Vitro Study ◽  
Chemical Components ◽  
Control Group ◽  
Osteoblast Proliferation ◽  
Mini Implants ◽  
Significant Difference ◽  
Implant Anchorage ◽  
Positive Effect

ABSTRACT Objective:  To evaluate the proliferation and morphology of human osteoblasts cultured on two brands of mini-implants after 24, 48, and 72 hours, in addition to the chemical composition found on their surface. Materials and Methods:  Two brands of mini-implant (Morelli and Neodent) were evaluated; polystyrene was used as a control group (n  =  3). Osteoblasts were cultured on the surface of sterilized mini-implants in a CO2 incubator at different time periods (24, 48, and 72 hours). Osteoblast proliferation was quantified by scanning electron microscopy using up to 5000× magnification, and cell morphology was analyzed by a single observer. For the chemical analysis, spectroscopy X-ray fluorescence was used to identify and quantify chemical components on the surface of the mini-implants. Results:  Two-way ANOVA showed no significant interaction between the factors studied (P  =  0.686). A Tukey test revealed no significant difference in osteoblast proliferation between the mini-implants at all studied periods; however, a difference in cell proliferation was detected between the Neodent and the control group (P  =  .025). For all groups, time had a direct and positive effect on osteoblast proliferation (P &lt; .001). The significant elements present in both brands of mini-implants were titanium, aluminum, vanadium, and iron. Conclusions:  Osteoblast proliferation was present on the mini-implants studied, which increased over time; however, no significant difference between brands was observed. No difference was seen between the mini-implants evaluated in terms of chemical composition. Cell adhesion after 72 hours suggests that areas of bone remodeling can be achieved, thus initiating the process of mini-implant anchorage.

A novel intracranial exchange guidewire improves the navigation of various endovascular devices: An in vitro study of challenging situations

2021 ◽  
pp. 159101992110573
Author(s):  
Naoki Kaneko ◽  
Ariel Takayanagi ◽  
Hamidreza Saber ◽  
Lea Guo ◽  
Satoshi Tateshima
Keyword(s):  
Giant Aneurysm ◽  
In Vitro Study ◽  
Target Vessel ◽  
Success Rates ◽  
Intracranial Stenting ◽  
Aneurysm Neck ◽  
Significant Difference ◽  
Aneurysm Model ◽  
Endovascular Devices

Objective Neuroendovascular procedures rely on successful navigation and stable access to the target vessel. The Stabilizer is a 300 cm long exchange wire with a 0.014 diameter and a soft, flexible stent at the distal end designed to assist with navigation and device delivery. This study aims to assess the efficacy of the Stabilizer for navigation in a variety of challenging environments. Methods The efficacy of the Stabilizer was evaluated using three challenging vascular models: a giant aneurysm model, a severe tortuosity model, and an M1 stenosis model. The Stabilizer was compared with a conventional wire during navigation in each model. Results In the giant aneurysm model, there was no significant difference of success during straightening of a looped wire and significantly higher success rates when advancing an intermediate catheter with the Stabilizer beyond the aneurysm neck compared to a conventional guidewire. The Stabilizer also significantly increased success rates when advancing an intermediate catheter through a model with severe tortuosity compared to a conventional guidewire, as well as exchange maneuver for intracranial stenting in a stenosis model compared to an exchange wire. Conclusions In our experimental model, the Stabilizer significantly improved navigation and device delivery in a variety of challenging settings compared to conventional wires.

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