scholarly journals Self-disinfecting Alginate vs Conventional Alginate: Effect on Surface Hardness of Gypsum Cast—An in vitro Study

2017 ◽  
Vol 18 (11) ◽  
pp. 1061-1064 ◽  
Author(s):  
Ajay Nagpal ◽  
Ranjith Madhavan ◽  
Navia George ◽  
Niharika R Thummala ◽  
SV Ravi
Keyword(s):  
Stainless Steel ◽  
Clinical Practice ◽  
Infection Control ◽  
Clinical Significance ◽  
Surface Hardness ◽  
In Vitro Study ◽  
Hardness Testing ◽  
Testing Data ◽  
The Mean

ABSTRACT Introduction For the construction of any dental prosthesis, accurate impressions are necessary. Hence, we undertook the present study to evaluate and compare the surface hardness of gypsum casts poured from impressions made using conventional alginate and self-disinfecting alginate. Materials and methods A total of 30 impressions of stainless steel die were made, out of which 15 impressions were made with conventional alginate and 15 were made with selfdisinfecting alginate and poured using Type III dental stone. Thirty stone specimens were subjected for hardness testing. Data were analyzed using independent samples t-test to compare the mean surface hardness. Results Difference in surface hardness was statistically insignificant (p > 0.05). Conclusion Surface hardness of gypsum casts poured using impressions made from self-disinfecting alginate and conventional alginates were comparable. Clinical significance Self-disinfecting alginates may be employed in clinical practice as safe and effective materials to overcome the infection control issues without compromising on the properties of the material. How to cite this article Madhavan R, George N, Thummala NR, Ravi SV, Nagpal A. Self-disinfecting Alginate vs Conventional Alginate: Effect on Surface Hardness of Gypsum Cast—An in vitro Study. J Contemp Dent Pract 2017;18(11):1061-1064.

scholarly journals Evaluation of marginal fit of two allceramic copings with two finish lines

2012 ◽  
Vol 06 (02) ◽  
pp. 163-168 ◽  
Author(s):  
Gulce Subasi ◽  
Nilgun Ozturk ◽  
Inan Ozgur ◽  
Nalan Bozogullari
Keyword(s):  
Stainless Steel ◽  
Analysis Of Variance ◽  
In Vitro Study ◽  
Finish Line ◽  
Marginal Fit ◽  
Luting Agent ◽  
All Ceramic ◽  
The Mean ◽  
Line Design

ABSTRACTObjectives: This in-vitro study investigated the marginal fit of two all-ceramic copings with 2 finish line designsMethods: Forty machined stainless steel molar die models with two different margin designs (chamfer and rounded shoulder) were prepared. A total of 40 standardized copings were fabricated and divided into 4 groups (n=10 for each finish line-coping material). Coping materials tested were IPS e.max Press and Zirkonzahn; luting agent was Variolink II. Marginal fit was evaluated after cementation with a stereomicroscope (Leica MZ16). Two-way analysis of variance and Tukey-HSD test were performed to assess the influence of each finish line design and ceramic type on the marginal fit of 2 all-ceramic copings (α =.05) Results: Two-way analysis of variance revealed no statistically significant differences for marginal fit relative to finish lines (P=.362) and ceramic types (P=.065)Conclusion: Within the limitations of this study, both types of all-ceramic copings demonstrated that the mean marginal fit was considered acceptable for clinical application (≤120 μm). (Eur J Dent 2012;6:163-168)

scholarly journals In Vitro Study on Bone Heating during Drilling of the Implant Site: Material, Design and Wear of the Surgical Drill

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1921 ◽  
Author(s):  
Juan Carlos Bernabeu-Mira ◽  
Hilario Pellicer-Chover ◽  
Miguel Peñarrocha-Diago ◽  
David Peñarrocha-Oltra
Keyword(s):  
Stainless Steel ◽  
Axial Loading ◽  
In Vitro Study ◽  
Material Design ◽  
Diamond Like Carbon ◽  
Thermal Variation ◽  
Mean Values ◽  
Carbon Coated ◽  
The Mean

Objective: An in vitro study was made to compare mean thermal variation according to the material, design and wear of the surgical drills used during dental implant site preparation. Material and methods: Three study groups (stainless steel drills with straight blades; diamond-like carbon-coated drills with straight blades; and diamond-like carbon-coated drills with twisted blades) were tested to compare material, design and wear of the surgical drill in terms of overall mean values (complete sequence of drills) and specific mean values (each drill separately). The groups comprised four drills: initial, pilot, progressive and final drill. Implant site configuration was performed through an intermittent and gradual drilling technique without irrigation at 800 rpm in standardized synthetic blocks. Maximum axial loading of two kilograms was controlled by an automatic press. Each surgical drill was submitted to 50 drillings and was sterilized every five uses. A thermographic camera analyzed the mean thermal changes. The software-controlled automatic press kept systematic drilling, axial loading and operational speed constant without any human intervention. Student’s t-test, ANOVA and multiple linear regression models were performed. The level of significance was 5% (p = 0.05). Results: The overall mean comparison between the stainless steel and diamond-like carbon-coated materials showed no statistically significant differences (p > 0.05), though specific mean comparison showed statistically significant differences between the drills of the different groups (p < 0.05). The twisted blades exhibited less overall and specific mean thermal variation than straight blades for the progressive and final drills (p < 0.01). In addition, the initial and pilot drills showed a greater mean thermal change than the progressive and final drills. The mean thermal variation was seen to increase during the 50 drillings. Conclusions: Within the limitations of this study, it can be concluded that the drill material did not significantly influence the overall mean thermal variation except for the pilot drill. The drill design affected overall and specific mean thermal variation since the twisted blades heated less than the straight blades. The initial and pilot drills increased the specific mean thermal variation with respect to the progressive and final drills. In addition, all drills in each group produced a gradual increase in mean temperature during the 50 drillings.

scholarly journals A Comparative Evaluation of Static Frictional Resistance Using Various Methods of Ligation at Different Time Intervals: An In Vitro Study

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Amanpreet Singh Natt ◽  
Amandeep Kaur Sekhon ◽  
Sudhir Munjal ◽  
Rohit Duggal ◽  
Anup Holla ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Frictional Resistance ◽  
Static Friction ◽  
Significant Difference ◽  
Dry Conditions ◽  
The Mean ◽  
Time Periods

Aim. To compare and evaluate the static frictional resistance offered by the four different types of ligation methods in both dry and wet conditions and at different durations when immersed in artificial saliva.Material and Methods. Alastik Easy to Tie modules, Super Slick Mini Stix elastomeric modules, Power “O” modules, and 0.009″Stainless Steel ligatures were used to compare the static friction using maxillary canine and premolar Preadjusted Edgewise brackets with 0.022″× 0.028″slot and 0.019″× 0.025″stainless steel wires.Results. The mean frictional resistance for Alastik modules was the lowest and that of Stainless Steel ligatures was found to be highest among the four groups compared and the difference among the four groups was statistically significant (P<0.005). The mean static frictional resistance in all groups under dry conditions was lower than that under wet conditions. No statistical significant differences were found when the groups were compared at different time periods of immersion in artificial saliva.Conclusion. This study concludes that the Alastik modules showed the lowest mean static frictional forces compared to any other ligation method, though no significant difference was found for different time periods of immersion in the artificial saliva.

scholarly journals Surface Hardness of Hybrid Ionomer with Different Curing Time (In Vitro Study)

2017 ◽  
Vol 1 ◽  
Author(s):  
Arfita Sipahutar ◽  
Astrid Yudhit ◽  
Rusfian Rusfian
Keyword(s):  
Standard Deviation ◽  
Surface Hardness ◽  
In Vitro Study ◽  
Hardness Test ◽  
Curing Time ◽  
Mean Values ◽  
The Mean ◽  
One Way Anova ◽  
Group 1

<p class="AbstractContent"><strong>Objective:</strong> The aim of this study was to evaluate the surface hardness of hybrid ionomer with different curing times (20, 30, 40, and 50 seconds).</p><p class="AbstractContent"><strong>Methods</strong>: This was an experimental laboratory with posttest only group design. Twenty-four disk shape hybrid ionomer specimens with a diameter of 5 mm and 2 mm in thickness were prepared and polymerized with Quartz Tungsten Halogen (QTH) for 20, 30, 40, and 50 seconds as group 1, 2, 3, and 4 respectively. All samples were immersed in distilled water under 37°C temperature for 24 hours as initial treatment. Surface hardness test was done using Vickers Hardness Test with load 50 gf for 20 second. The Data was analyzed with one way ANOVA (<em>p </em>≤ 0.05).</p><p class="AbstractContent"><strong>Results</strong>: Using one way anova test (<em>p </em>≤ 0.05) shows the mean and standard deviation of the group 1 is 25,900 ± 2,5659VHN; group 2 is 29,800 ± 1,1983 VHN; group 3 is 31,283 ± 0,5037 VHN; group 4 is 36, 183 ± 2,3430 VHN and the obtained value <em>p </em>= 0.000 (<em>p </em>≤ 0.05).</p><p class="AbstractContent">The mean values and standard deviation were 25.900 ± 2.5659 VHN; 29.800 ± 1.1983 VHN; 31.283 ±0.5037 VHN; 6.183 ± 2.3430 VHN for group 1, 2, 3, and 4 respectively. Statistic analyzed showed a significant different among groups with <em>p</em> value =0.000 (<em>p</em> &lt; 0.05).</p><strong>Conclusion</strong> There are significant differences in surface hardness of hybrid ionomer with different curing time (20, 30,40, and 50 seconds). The longer curing time will increase the surface hardness of hybrid ionomer.

scholarly journals COMPARATIVE EVALUATION OF RETENTION AND FRACTURE RESISTANCE OF ENDODONTICALLY TREATED TEETH REINFORCED WITH THREE DIFFERENT POSTS SYSTEMS: AN IN VITRO STUDY

2020 ◽  
pp. 1-3
Author(s):  
Deebah Choudhary
Keyword(s):  
Stainless Steel ◽  
Glass Fiber ◽  
Fracture Resistance ◽  
In Vitro Study ◽  
Fracture Load ◽  
Fiber Post ◽  
Endodontically Treated Teeth ◽  
Glass Fiber Post ◽  
The Mean

Aim: To compare the retention and fracture resistance of three different pre-fabricated posts systems in endodontically treated anterior tooth. Materials and Methods: Root canal treatment was performed for all the 90 samples used in the study. After the completion of obturation, post space preparation was done accompanied by post cementation. The samples were divided into three groups depending on the post cemented (Stainless Steel, Glass fiber and Ceramic post). The samples were first evaluated for retention with a help of a three-jaw chuck, which grasped the post and tried to pull it out. The force required to dislodge each post was recorded in Newtons. To evaluate the fracture resistance, the samples were subjected to compressive loads at an angle. The load required was then recorded in Newtons. Results: The mean retention values for Stainless Steel post were significantly greater than those for Glass fiber post and Ceramic post. The mean retention values of glass-fiber post and ceramic post were not statistically different. The fracture load of the post system, it was revealed that highest mean value was seen in Stainless Steel post and was significant than ceramic post and glass-fiber post. Conclusion: Within the limitation of this study, it can be concluded that the pre-fabricated stainless steel post exhibits a significantly higher fracture resistance and also the retention was more as compared to Glass fiber post and Ceramic post.

scholarly journals Scanning Accuracy of Bracket Features and Slot Base Angle in Different Bracket Materials by Four Intraoral Scanners: An In Vitro Study

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 365
Author(s):  
Seon-Hee Shin ◽  
Hyung-Seog Yu ◽  
Jung-Yul Cha ◽  
Jae-Sung Kwon ◽  
Chung-Ju Hwang
Keyword(s):  
Stainless Steel ◽  
In Vitro Study ◽  
Sem Images ◽  
Polycrystalline Alumina ◽  
Base Angle ◽  
Accurate Expression ◽  
Dental Model ◽  
Alumina Composite ◽  
The Difference

The accurate expression of bracket prescription is important for successful orthodontic treatment. The aim of this study was to evaluate the accuracy of digital scan images of brackets produced by four intraoral scanners (IOSs) when scanning the surface of the dental model attached with different bracket materials. Brackets made from stainless steel, polycrystalline alumina, composite, and composite/stainless steel slot were considered, which have been scanned from four different IOSs (Primescan, Trios, CS3600, and i500). SEM images were used as references. Each bracket axis was set in the reference scan image, and the axis was set identically by superimposing with the IOS image, and then only the brackets were divided and analyzed. One-way analysis of variance (ANOVA) was used to compare the differences. The difference between the manufacturer’s nominal torque and bracket slot base angle was 0.39 in SEM, 1.96 in Primescan, 2.04 in Trios, and 5.21 in CS3600 (p < 0.001). The parallelism, which is the difference between the upper and lower angles of the slot wall, was 0.48 in SEM, 7.00 in Primescan, 5.52 in Trios, 6.34 in CS3600, and 23.74 in i500 (p < 0.001). This study evaluated the accuracy of the bracket only, and it must be admitted that there is some error in recognizing slots through scanning in general.

scholarly journals Shear bond strength evaluation of bonded molar tubes on fluorotic molars

2012 ◽  
Vol 83 (1) ◽  
pp. 152-157 ◽  
Author(s):  
Erika L. Silva-Benítez ◽  
Veronica Zavala-Alonso ◽  
Gabriel A. Martinez-Castanon ◽  
Juan P. Loyola-Rodriguez ◽  
Nuria Patiño-Marin ◽  
...  
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Dental Fluorosis ◽  
In Vitro Study ◽  
Mean Value ◽  
Fixed Appliance ◽  
Adhesive Remnant Index ◽  
The Mean ◽  
Electronic Microscope

Abstract Objective: To study the shear bond strength (SBS), sites of failure, and micromorphology of bonded molar tubes used on teeth affected by dental fluorosis. Materials and Methods: This in vitro study included 140 first molars classified according to Dean's index for dental fluorosis. Samples were divided into seven groups: (1) healthy teeth etched for 15 seconds, (2) teeth with moderate fluorosis (MOF) etched for 15 seconds, (3) teeth with MOF etched for 150 seconds, (4) teeth with MOF microabrasion etched for 15 seconds, (5) teeth with severe fluorosis (SEF) etched for 15 seconds, (6) teeth with SEF etched for 150 seconds, and (7) teeth with SEF microabrasion etched for 15 seconds. All samples were incubated and were then submitted to the SBS test and evaluated with the modified adhesive remnant index (ARI) and analyzed by using a scanning electronic microscope. Results: The SBS mean value for healthy enamel was 20 ± 10.2 MPa. For the group with MOF, the etched 150-second mean value was the highest (19 ± 7.6 MPa); for the group with SEF treated with microabrasion and etched for 15 seconds, the mean value was (13 ± 4.1 MPa). Significant differences (P ≤ .05) were found in the ARI between healthy and fluorosed groups. Conclusions: Fluorotic enamel affects the adhesion of bonded molar tubes. The use of overetching in cases of MOF and the combination of microabrasion and etching in SEF provides a suitable adhesion for fixed appliance therapy.

scholarly journals Impact of refrigeration on the surface hardness of hybrid and microfilled composite resins

2009 ◽  
Vol 20 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Fernando Henrique Ruppel Osternack ◽  
Danilo Biazzetto de Menezes Caldas ◽  
Rodrigo Nunes Rached ◽  
Sérgio Vieira ◽  
Jeffrey A. Platt ◽  
...  
Keyword(s):  
Room Temperature ◽  
Surface Hardness ◽  
In Vitro Study ◽  
Knoop Hardness ◽  
Composite Resins ◽  
Bottom Surface ◽  
Steel Mold ◽  
Polymerization Condition ◽  
Post Hoc

This in vitro study evaluated the Knoop hardness of the composite resins Charisma® (C) and Durafill VS® (D) polymerized in 3 different conditions: at room temperature (A) (23 ± 1°C); refrigerated at 4 ± 1°C and immediately photo-activated after removal from the refrigerator (0); and, refrigerated at 4 ± 1°C and photo-activated after a bench time of 15 min at room temperature (15). One hundred and twenty specimens (4 mm diameter and 2 mm depth) were made using a stainless steel mold and following manufacturer's instructions. All specimens were tested immediately after polymerization (I) and after 7 days of water storage in the dark at room temperature (7d). The data were subjected to ANOVA and post-hoc Tukey's test (a=0.05). On the top surface, CAI was statistically similar to C15I and DAI to D15I (p>0.05). On the bottom surface, CAI presented higher hardness values when compared to COI and C15I (p<0.05). The D groups showed no significant differences (p>0.05) on the bottom surfaces for any tested polymerization condition. After 7 days of storage, the Knoop hardness decreased significantly (p<0.05) for groups C7d and D7d except for C07d, which was not different from COI at either surface (p>0.05). D07d showed higher Knoop hardness (p<0.05) values on the top surface when compared to the other groups.

scholarly journals An in vitro comparison of the force decay generated by different commercially available elastomeric chains and NiTi closed coil springs

2007 ◽  
Vol 21 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Ana Cristina Soares Santos ◽  
André Tortamano ◽  
Sandra Regina Frazatto Naccarato ◽  
Gladys Cristina Dominguez-Rodriguez ◽  
Julio Wilson Vigorito
Keyword(s):  
Artificial Saliva ◽  
Testing Machine ◽  
In Vitro Study ◽  
Original Length ◽  
Force Decay ◽  
Decay Pattern ◽  
The Mean ◽  
Initial Force ◽  
Elastomeric Chains

This in vitro study was designed to compare the forces generated by commercially available elastomeric chains and NiTi closed coil springs, and to determine their force decay pattern. Forty elastomeric chains and forty NiTi closed coil springs were divided into 4 groups according to the following manufacturers: (1) Morelli®, (2) Abzil®, (3) TP Orthodontics® and (4) American Orthodontics®. The specimens were extended to twice their original length and stored in artificial saliva at 37°C. Initial force was measured by means of an Instron universal testing machine and then at 1, 4, 7, 14, 21, and 28 days. The results revealed that the elastomeric chains delivered a mean initial force of 347 g for Morelli®, 351 g for American Orthodontics®, 402 g for Abzil®, and 404 g for TP Orthodontics®. The NiTi closed coil springs generated a mean initial force of 196 g for American Orthodontics®, 208 g for TP Orthodontics®, 216 g for Abzil®, and 223 g for Morelli®. The mean percentage of force decay observed after 28 days for the elastomeric chains was 37.4% for TP Orthodontics®, 48.1% for American Orthodontics®, 65.4% for Morelli®, and 71.6% for Abzil®. After 28 days, the NiTi closed coil springs presented a mean percentage of force decay of 22.6% for American Orthodontics®, 29.8% for Abzil®, 30.6% for Morelli®, and 45.8% for TP Orthodontics®. At the end of the study, significant differences were observed between the elastomeric chains and the NiTi closed coil springs. The results indicated that the studied NiTi closed coil springs are more adequate for dental movement than the elastomeric chains.

Sign in / Sign up

Export Citation Format

Share Document