scholarly journals Influência da polimerização adicional na microdureza de compósitos diretos para uso indireto: estudo in vitro

2020 ◽  
Vol 42 ◽  
pp. e35
Author(s):  
Carlos Henrique Camilo Marcehsan ◽  
Angela Isabel dos Santos Dullius ◽  
Angela Pellegrin Ansuj ◽  
Vinícius Pinheiro Nunes ◽  
Gislaine Rosa Biachi
Keyword(s):  
Analysis Of Variance ◽  
Composite Resin ◽  
The Other ◽  
Distilled Water ◽  
Led Light ◽  
Post Hoc

The aim of this study was to verify the effect of additional polymerization with microwave and autoclave on the microhardness of 3 different commercial brands of composite resin compared to the ceromere. Cylindrical specimens (6mm x 3mm) were made with a split matrix divided into 10 groups of 13 bodies, with: Photoactivation (LED light on the top surface-40s; photoactivation LED + microwave (500W per 3min) immersed in 100ml distilled water and Photoactivation LED + autoclave (full cycle). The Ceromere group was activated according to the manufacturer's recommendation. The specimens went through a finishing and polishing sequence being stored with a cotton moistened in distilled water for 24h. They were taken to the microhardness meter (three dentations, 50g/15s load). The analysis of variance (ANOVA) was performed with post hoc Games Howell at a level of 5%. It was verified that the ceromere did not differ from the groups Z250 photo and microwave, but was inferior to the Z250 group with autoclave, and the microhardness of this was higher than the other groups. The Tetric group was inferior to all other groups. It was concluded that the additional polymerization methods promoted an increase of the superficial microhardness of the Z250 resin and this did not present a difference of microhardness when compared to the Ceromere

Effect of Beverages on Color and Translucency of New Tooth-Colored Restoratives

2015 ◽  
Vol 40 (2) ◽  
pp. E56-E65 ◽  
Author(s):  
BL Tan ◽  
AUJ Yap ◽  
HNT Ma ◽  
J Chew ◽  
WJ Tan
Keyword(s):  
Green Tea ◽  
Analysis Of Variance ◽  
Orange Juice ◽  
Red Wine ◽  
Composite Resin ◽  
Inverse Correlation ◽  
Distilled Water ◽  
B Values ◽  
Restorative Materials ◽  
Post Hoc

ABSTRACT This investigation examined the susceptibility to staining and translucency changes of some new tooth-colored restorative materials after immersion in different beverages. The materials studied were 3M Filtek Z350XT (ZT), 3M Filtek 350XT Flowable Restorative (ZF), Shofu Beautifil Flow Plus (BF), Shofu Beautifil II (B2), 3M Ketac Nano (N100), and 3M Photac Fil (PF). Following the manufacturers' instructions, 42 samples were made from each material and placed in an incubator at 100% humidity and 37°Celsius for 24 hours. Baseline L*, a*, b* readings were taken against white and black backgrounds using a photospectrometer. The samples were then randomly assigned to be immersed in seven beverages, namely cola drink, orange juice, red wine, vodka, black coffee, green tea, and distilled water for a period of seven days. Color readings were taken again by recording the L*, a*, b* values. Data was analyzed using t-tests, one-way analysis of variance with Tukey post hoc and Pearson's correlation (p<0.05). BF generally performed as well as the conventional composite resin materials (ZT and ZF) but N100 and B2 did not. PF had the largest staining and translucency changes. Coffee, red wine, and tea resulted in the most staining and negative translucency changes. An inverse correlation between ΔE and ΔTP was observed for all materials and beverages with the exception of orange juice.

Psychophysically Based Physical Capability Limits For Right Angle Power Tool Operation

2020 ◽  
Vol 64 (1) ◽  
pp. 910-914
Author(s):  
Jonathan Valencia ◽  
Joel Cort
Keyword(s):  
Analysis Of Variance ◽  
The Other ◽  
Mixed Design ◽  
Joint Orientation ◽  
Physical Capability ◽  
Subject Variables ◽  
Group A ◽  
Repeated Analysis ◽  
Post Hoc

A psychophysical methodology was utilized to examine 40 non-skilled female participants performing right-angle power tool (RAPT) fastening tasks. A combination of two between subject variables were examined for a total of four between-subject groups: joint orientation (horizontal and vertical planes) and joint hardness (hard and soft joints). Participants were evenly distributed into one of four joint orientation- hardness groups. Within each group, a combination of three fastening strategies and three fastening frequencies were performed by each participant. The chosen target torque determined the physical capability limits (PCL). A mixed-design repeated analysis of variance with Tukey’ significance post hoc test were used to determine any significance with the measured variables ( p<0.05). Fastening strategy and frequency influenced the chosen torque magnitude. Participants chose significantly higher target torques with the Turbo Tight strategy in comparison to the other two strategies. Furthermore, participants chose to accept lower target torques and forces as fastening frequency increased.

scholarly journals Fracture resistance of simulated immature teeth after apexification with calcium silicate-based materials

2016 ◽  
Vol 10 (02) ◽  
pp. 188-192 ◽  
Author(s):  
Evren Ok ◽  
Mustafa Altunsoy ◽  
Mehmet Tanriver ◽  
Ismail Davut Capar ◽  
Abdussamed Kalkan ◽  
...  
Keyword(s):  
Analysis Of Variance ◽  
Calcium Silicate ◽  
Fracture Resistance ◽  
Composite Resin ◽  
Mineral Trioxide Aggregate ◽  
Control Group ◽  
Fiber Post ◽  
Immature Teeth ◽  
Post Hoc

ABSTRACT Objective: To compare the fracture resistance of simulated immature teeth filled with an apical barrier of mineral trioxide aggregate (MTA), Biodentine, and calcium-enriched mixture (CEM). Materials and Methods: Fifty-two single-rooted human maxillary central incisors were used. For standardization, the teeth were sectioned 6 mm above and 9 mm below the cementoenamel junction to simulate immature apex. Simulations of roots into immature apices were carried out using 1.5 mm diameter drills. The specimens were then randomly divided into three experimental groups (n = 13) and one control group (n = 13). In experimental groups, MTA, Biodentine, and CEM were placed to apical 4 mm of the simulated immature roots. The samples were stored at 37°C and 100% humidity for 1 week. A load was applied on the crown of all teeth at 135° to their long axis until fracture. The data were analyzed using one-way analysis of variance and Tukey post-hoc tests. Results: No statistically significant differences were found among MTA, CEM, and Biodentine (P > 0.05), and these groups demonstrated higher fracture resistance than control group (P < 0.05). Conclusions: Using any of the MTA, Biodentine, and CEM as an apical plug and restoring with fiber post and composite resin increases the fracture resistance of immature teeth.

scholarly journals Superelasticity and force plateau of nickel-titanium springs: an in vitro study

2016 ◽  
Vol 21 (3) ◽  
pp. 46-55 ◽  
Author(s):  
Camila Ivini Viana Vieira ◽  
Sergei Godeiro Fernandes Rabelo Caldas ◽  
Lídia Parsekian Martins ◽  
Renato Parsekian Martins
Keyword(s):  
Analysis Of Variance ◽  
In Vitro Study ◽  
Nickel Titanium ◽  
Vitro Study ◽  
Lack Of Information ◽  
Activation Force ◽  
Post Hoc

abstract Objective: This paper analyzed whether nickel-titanium closed coil springs (NTCCS) have a different superelastic (SE) behavior according to activation and whether their force plateau corresponds to that informed by the manufacturer. Methods: A total of 160 springs were divided into 16 subgroups according to their features and activated proportionally to the length of the extensible part (NiTi) of the spring (Y). The force values measured were analyzed to determine SE rates and force plateaus, which were mathematically calculated. These plateaus were compared to those informed by the manufacturer. Analysis of variance was accomplished followed by Tukey post-hoc test to detect and analyze differences between groups. Results: All subgroups were SE at the activation of 400% of Y length, except for: subgroups 4B and 3A, which were SE at 300%; subgroups 4E and 4G, which were SE at 500%; and subgroup 3C, which was SE at 600%. Subgroup 3B did not show a SE behavior. Force plateaus depended on activation and, in some subgroups and some activations, were similar to the force informed. Conclusions: Most of the springs showed SE behavior at 400% of activation. Force plateaus are difficult to compare due to lack of information provided by manufacturers.

Effect of Tooth-Whitening Procedures on Stained Composite Resins

2019 ◽  
Vol 44 (1) ◽  
pp. 65-75 ◽  
Author(s):  
JW Reinhardt ◽  
MM Balbierz ◽  
CM Schultz ◽  
B Simetich ◽  
MW Beatty
Keyword(s):  
Red Wine ◽  
Composite Resin ◽  
Color Change ◽  
Composite Resins ◽  
The Other ◽  
Time Interval ◽  
Distilled Water ◽  
Water Control ◽  
Tooth Whitening ◽  
Final Composite

SUMMARY In this laboratory study, a composite resin was stained to a visibly discernible level using both coffee and red wine over 14 days (change was considered clinically noticeable and significant when ΔEab*≥2.7). Color change was measured at one, three, seven, and 14 days of staining. Although the nature of color change was different for the two staining solutions, the overall degree of staining (ΔEab*) rendered by either coffee or wine at each time interval was not significantly different (p≥0.05). Four whitening protocols were applied to stained composites. Treatment included applications of distilled water (control), Crest Pro-Health [HD] toothpaste, Crest Whitestrips, Opalescence PF bleach (15%), and application of a fine pumice polishing (Preppies). HD toothpaste and Whitestrips were applied daily for 21 days, Opalescence was applied daily for 10 days, and polishing was applied once. Each of the whitening products, applied in a manner simulating at-home or in-office treatment, was effective in producing color improvements (lightening) over controls (p&lt;0.05), but none of the four treatments produced lightening that was significantly different from the other treatments (p≥0.05). A comparison of final composite color with that measured at baseline showed that Opalescence returned composite color to an acceptable level following exposure to both staining solutions (ΔEab*&lt;2.7), Whitestrips returned color close to baseline for wine-stained composites, and HD paste and polishing permitted residual stain to remain (ΔEab*≥2.7).

A Fluoride-containing Composite Resin—An In Vitro Study of a New Material for Orthodontic Bonding

1989 ◽  
Vol 16 (3) ◽  
pp. 207-212 ◽  
Author(s):  
P. A. Cook ◽  
C. C. Youngson
Keyword(s):  
Bond Strength ◽  
Composite Resin ◽  
Glass Ionomer Cement ◽  
In Vitro Study ◽  
The Other ◽  
Glass Ionomer ◽  
New Material ◽  
Bond Strengths ◽  
Ionomer Cement

The shear/peel bond strength of a new material, a ‘hybrid’ of a composite resin and a glass ionomer cement, was compared in vitro with the bond strengths of a composite resin and of a glass ionomer cement. The new material had a significantly greater bond strength than the other materials tested and its properties were very similar to the composite resin. Unlike the glass ionomer cement, etching of the enamel before applying the adhesive is required. The clinical indications for using this new cement are discussed.

scholarly journals Influence of Different Enamel Shades and Thickness on Chroma and Value of Dentin Vita Shade: An in vitro Comparative Assessment Study

2015 ◽  
Vol 16 (4) ◽  
pp. 304-309 ◽  
Author(s):  
N Meena ◽  
Deepak Mehta ◽  
Noor Saira Wajid Najma Hajira ◽  
P Ashwini ◽  
HL Usha
Keyword(s):  
Composite Resin ◽  
Pearson Correlation ◽  
Correlation Coefficients ◽  
Comparative Assessment ◽  
Optimum Thickness ◽  
Assessment Study ◽  
Natural Teeth ◽  
Post Hoc ◽  
One Way Anova

ABSTRACT Background The aim of the present study is to determine the influence of different enamel shades of various thickness on chroma and value of vita shade of dentin. Materials and methods Three enamel composite resin shades (Enamel white, grey and neutral) and one dentin shade (A2) from Amelogen Plus (Ultradent) was used. Ninety Enamel disk specimens of 0.5, 0.75 and 1 mm thickness and 10 mm in diameter for each shade and 90 dentin disk specimens of 2 mm in thickness and 10 mm in diameter was used for the study. The spectrophotometric values of the dentin shade with and without enamel specimens were recorded and the values were converted to CIE L*a*b values. Results Statistical analysis was done using Pearson correlation coefficients to verify the effect of thickness on Chroma and value, and the significance was evaluated by one-way ANOVA and Tukey post hoc test. Two way ANOVA and Tukey post hoc was done to verify the variation within the groups. Results revealed a significant positive correlation between thickness and chroma and a negative correlation between thickness and value. There was a statistically significant variation in between the groups. Conclusion All groups produced a significant increase in chroma with increase in thickness of enamel shade upto a thickness of 0.75 mm after which the behavior of each shade was erratic. Hence, the optimum thickness would be 0.75 mm. All groups produced a significant decrease in value with increase in thickness of enamel shade. Enamel white produced the greatest reduction in value, enamel neutral the least and enamel grey demonstrated an intermediate result. Clinical significance There is a need to have a knowledge of the effect on chroma and value when dentin is layered with different enamel shades, it is also important to understand the effect of these enamel shades at different thicknesses to better control the color and reproduce esthetic simulating natural teeth. How to cite this article Hajira NSWN, Mehta D, Ashwini P, Meena N, Usha HL. Influence of Different Enamel Shades and Thickness on Chroma and Value of Dentin Vita Shade: An in vitro Comparative Assessment Study. J Contemp Dent Pract 2015;16(4):304-309.

scholarly journals Surface Roughness of Bulk Fill Composite after Simulated Toothbrushing with Different Dentifrices

2020 ◽  
Vol 8 (D) ◽  
pp. 166-172
Author(s):  
Ahmed Mohamed Elmarakby ◽  
Mahmoud Darwish ◽  
Yasser R. Souror ◽  
Ahmed Waly
Keyword(s):  
Surface Roughness ◽  
Chemical Composition ◽  
Analysis Of Variance ◽  
Composite Resin ◽  
In Vitro Study ◽  
Resin Composites ◽  
Composite Surface ◽  
Significance Level ◽  
Composite Resin Restorations

AIM: The aim of the current in vitro study was to evaluate the changes in surface roughness of bulk fill composites after simulated toothbrushing with different dentifrices. MATERIALS AND METHODS: Three types of bulk fill resin composites were used in this study; 27 specimens of each composite resin were randomly divided into three main groups (n = 9). Each main group was further subdivided into three subgroups (n = 3). Each group was subjected to simulated toothbrushing with three different dentifrices. One-way analysis of variance was used to evaluate the effect of brushing using dentifrices on the surface roughness of each type of composite resin, followed by Tukey’s test at a significance level of p ≤ 0.5%. RESULTS: Results revealed that different effects on composite surface roughness were detected after simulating toothbrushing with different dentifrices. Lacalut toothpaste abrades more with Filtek Bulk Fill, Tetric N-Ceram then Bulk Fill SDR. Crest 3D toothpaste abrades more with Tetric N-Ceram, Bulk Fill SDR then Filtek Bulk Fill. BlanX toothpaste abrades more with Tetric N-Ceram, Bulk Fill SDR then Filtek Bulk Fill. CONCLUSION: Chemical composition of both resin composites and dentifrices plays an important role in influencing the degree of surface roughness of bulk fill composite resin restorations.

scholarly journals In Vitro Evaluation of Physical and Mechanical Properties of Light-Curing Resin Cement: A Comparative Study

2020 ◽  
Vol 14 (01) ◽  
pp. 152-156
Author(s):  
Luís Felipe Espíndola-Castro ◽  
Oscar Felipe Fonseca de Brito ◽  
Larissa Gabrielle Assis Araújo ◽  
Izabella Luiza Aragão Santos ◽  
Gabriela Queiroz De Melo Monteiro
Keyword(s):  
Color Change ◽  
Surface Hardness ◽  
Color Stability ◽  
Resin Cement ◽  
The Other ◽  
Distilled Water ◽  
Water Control ◽  
Mean Values ◽  
Significance Level

Abstract Objective The aim of study was to evaluate in vitro the surface hardness, sorption, solubility, and color stability of three light-cured resin cements, namely RelyX Veneer (RLX), Variolink Veneer (VLK), and All Cem Veneer (ACV). Materials and Methods Cylindrical samples (15 × 1 mm) were made for each group using a metallic mold (n = 10). Vickers microhardness test was performed, and average hardness was calculated from three indentations (300 gf/15s) per sample. The sorption and solubility of the materials were evaluated according to ISO 4049:2009 based on three samples weighing: initial (m 1), after immersion in distilled water for 7 days (m 2), and final (after removal of all moisture [m 3]). The color change was observed using a digital spectrophotometer, at three different time points, baseline, 1 day, and 1 week of immersion in coffee and distilled water (control). Statistical Analysis Shapiro–Wilk test was used to analyze the normality of the data, and groups were compared using Kruskal–Wallis and Mann–Whitney tests. A significance level of 5% was used. Results RLX showed the highest microhardness mean values (36.96 VHN), but higher sorption (23.2 µg/mm3) and solubility (2.40 µg/mm3), with statistically significant differences with the other groups. For color stability, higher ∆E was observed for the samples immersed in coffee (p = 0.009). The VLK resin cement presented statistically significant differences from the other groups, with higher color changes in coffee at 1 day (15.14) and after 1 week (23.65). Conclusion RLX resin cement showed better hardness results. All materials tested performed satisfactorily for sorption and solubility according to ISO 4049:2009. All materials showed high-staining values after 1 week of immersion in coffee.

scholarly journals An In Vitro Assessment of Gutta-Percha Coating of New Carrier-Based Root Canal Fillings

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Raghad Abdulrazzaq Alhashimi ◽  
Richard Foxton ◽  
Shihab Romeed ◽  
Sanjukta Deb
Keyword(s):  
Bond Strength ◽  
Analysis Of Variance ◽  
Root Canal ◽  
Microcomputed Tomography ◽  
Gutta Percha ◽  
Orthodontic Wire ◽  
In Vitro Assessment ◽  
Post Hoc ◽  
Push Out

The first aim of this paper was to evaluate the push-out bond strength of the gutta-percha coating of Thermafil and GuttaCore and compare it with that of gutta-percha used to coat an experimental hydroxyapatite/polyethylene (HA/PE) obturator. The second aim was to assess the thickness of gutta-percha around the carriers of GuttaCore and HA/PE obturators using microcomputed tomography (μCT). Ten (size 30) 1 mm thick samples of each group (Thermafil, GuttaCore, and HA/PE) were prepared. An orthodontic wire with a diameter of 0.5 mm was attached to the plunger of an Instron machine in order to allow the push-out testing of the gutta-percha coating. Five samples of (GuttaCore and HA/PE) were scanned usingμCT. The data obtained were analysed with one-way analysis of variance and Tukey post hoc test. HA/PE obturators exhibited significantly higher push-out bond strength (P<0.001) determined at 6.84 ± 0.96 than those of Guttacore around 3.75 ± 0.75 and Thermafil at 1.5 ± 0.63. GuttaCore demonstrated significantly higher bond strength than Thermafil (P<0.001).μCT imaging revealed that the thickness of gutta-percha around the experimental HA/PE carrier was homogeneously distributed. The bondability and thickness of gutta-percha coating around HA/PE carriers were superior to those of GuttaCore and Thermafil obturators.

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