scholarly journals Evaluation of Dual-Cure Resin Cement Polymerization under Different Types and Thicknesses of Monolithic Zirconia

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Pinar Turkoglu ◽  
Deniz Sen
Keyword(s):  
Vickers Hardness ◽  
Resin Cement ◽  
Different Types ◽  
Monolithic Zirconia ◽  
Different Depths ◽  
Post Hoc ◽  
One Way Anova

Purpose. The aim of the present study was to investigate the effects of the type and thickness of the zirconia material on the microhardness of the underlying dual-cure resin cement. Materials and Methods. Eight disk-shaped zirconia specimens with a 4-mm diameter and four varying thicknesses (0.5, 1.0, 1.5, and 2.0 mm) were fabricated from two different monolithic zirconia materials: posterior monolithic zirconia (Prettau) and anterior monolithic zirconia (Prettau Anterior). Dual-cure resin cement specimens with a 4-mm diameter and 5-mm height were prepared using Teflon cylinder molds and activated by light beneath the eight zirconia disks and without any zirconia disk for 20 s (n=12). A total of 108 specimens were embedded in acrylic. Vickers hardness of each specimen was measured at three different depths using a microhardness device with a 50-g load. All data were statistically evaluated using three-way ANOVA, one-way ANOVA, independent samples t-tests, and Bonferroni corrected post hoc tests (α=.05). Results. Dual-cure resin cement’s microhardness was significantly higher for the samples polymerized beneath anterior monolithic zirconia compared to posterior monolithic zirconia. The hardness decreased as the thickness increased for both types of zirconia; the latter was attributed to an attenuated curing efficiency. Conclusion. Microhardness of the dual-cure resin cement is influenced by both the type and the thickness of the monolithic zirconia restoration. Polymerization efficiency for resin cement cured under anterior monolithic zirconia may be superior to cured beneath posterior monolithic zirconia.

scholarly journals Biaxial flexural strength of different types of monolithic zirconia

2019 ◽  
Vol 22 (1) ◽  
pp. Process
Author(s):  
Shereen Ahmed Nossair ◽  
Tarek Salah ◽  
Kamal Khaled Ebeid
Keyword(s):  
Flexural Strength ◽  
Zirconia Ceramic ◽  
Group 4 ◽  
Dental Esthetics ◽  
Biaxial Flexural Strength ◽  
Different Types ◽  
Monolithic Zirconia ◽  
Group 5 ◽  
Group 2 ◽  
Post Hoc

Objective: This study was designed to evaluate the biaxial flexural strength (BFS) of different types of unshaded and shaded monolithic zirconia. Material and Methods: 120 monolithic zirconia ceramic discs were fabricated. They were divided into twelve groups (n=10), Group 1; Bruxzir unshaded, Group 2; Bruxzir shaded A2, Group 3; Bruxzir anterior white, Group 4; Bruxzir anterior shade A2, Group 5; Prettau unshaded, Group 6; Prettau shaded with A2 coloring liquid, Group 7; Prettau anterior white, Group 8; Prettau anterior shaded with A2 coloring liquid, Group 9; Katana HT white, Group 10; Katana HT shade A2, Group 11; Katana ST white, Group 12; Katana ST shade A2. All discs were milled using a dental milling machine, and had final dimensions after sintering of 15 mm diameter and 1 mm thickness. BFS was tested using piston on three ball technique. Results:  One-way ANOVA revealed significant differences among the 12 groups. Tukey post-hoc tests revealed no significant differences between the groups 3, 4, ,7 ,8 11, and 12. However, they all had BFS values that are significantly lower than all other groups. Group 2 showed statistically significant higher BFS values when compared to group 3,4, 7, 8, 11, and 12 while it showed statistically significant lower values when compared to groups 1, 5, 6, 9, and 10. Conclusion: Increase in the yttria content in zirconia led to a decrease in its BFS. Shading of zirconia did not have a significant effect on the final strength of zirconia. KeywordsDental ceramics; Dental esthetics; Flexural strength; Shaded zirconia. 

scholarly journals Effect of Ceramic Interposition and Post-activation Times on Knoop Hardness of Different Shades of Resin Cement

2018 ◽  
Vol 29 (1) ◽  
pp. 76-81 ◽  
Author(s):  
Marina Barrêto Pereira Moreno ◽  
Ana Rosa Costa ◽  
Frederick Allen Rueggeberg ◽  
Américo Bortolazzo Correr ◽  
Mário Alexandre Coelho Sinhoreti ◽  
...  
Keyword(s):  
Light Exposure ◽  
Knoop Hardness ◽  
Resin Cement ◽  
Cross Sectional ◽  
Commercial Resin ◽  
Cure Time ◽  
Different Depths ◽  
Activation Times ◽  
Post Hoc ◽  
Made In

Abstract The aim of this study was to evaluate Knoop hardness of different shades of a resin cement light-cured directly or through ceramic discs, measured 15 min or 24 h after light exposure, and at different depths. Specimens of a commercial resin cement (Variolink Veneer) in seven shades, were fabricated in an elastomeric mold, covered with a mylar strip, a 0.7 mm thick ceramic disc (IPS e.max Press) was placed and the cement was light-activated for 20 s using a blue LED (Radii-Cal). The cured resin cement specimens were transversely wet-flattened to their middle portion and microhardness (Knoop) values were recorded at 15 min after light exposure and after deionized water storage at 37 ºC for 24 h. Five indentations were made in the cross-sectional area at 100 and 700 μm depths from the top surface. Ten specimens were made for each test conditions. Data were submitted to ANOVA split-plot design (shade, post-cure time, mode of activation and depth), followed by Tukey post hoc test (α=0.05). Significant differences for shade (p<0.0001), mode of activation (p<0.001), post-cure time (p<0.0001) and depth (p<0.0001) were detected. No significant interactions (p>0.05) were found, except for shade x post-cure time (p<0.0045) and mode of activation x post-cure time (p<0.0003). Resin cement shade has a significant effect on Knoop hardness. Indirect activation through a ceramic material reduced significantly Knoop hardness. Hardness Knoop significantly increased after 24 h in all cements shades compared to values obtained after 15 min. Resin cement depth significantly reduced Knoop hardness.

scholarly journals Comparison of Orthodontic Bracket Debonding Force and Bracket Failure Pattern on Different Teeth In Vivo by a Prototype Debonding Device

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Tamzid Ahmed ◽  
Norma Ab Rahman ◽  
Mohammad Khursheed Alam
Keyword(s):  
Failure Pattern ◽  
Point Scale ◽  
Orthodontic Bracket ◽  
Adhesive Remnant Index ◽  
Significant Difference ◽  
Different Types ◽  
Post Hoc ◽  
Bracket Failure ◽  
One Way Anova

Objective. To compare the orthodontic bracket debonding force and assess the bracket failure pattern clinically between different teeth by a validated prototype debonding device. Materials and Method. Thirteen (13) patients at the end of comprehensive fixed orthodontic treatment, awaiting for bracket removal, were selected from the list. A total of 260 brackets from the central incisor to the second premolar in both jaws were debonded by a single clinician using a validated prototype debonding device equipped with a force sensitive resistor (FSR). Mean bracket debonding forces were specified to ten (10) groups of teeth. Following debonding, Intraoral microphotographs of the teeth were taken by the same clinician to assess the bracket failure pattern using a 4-point scale of adhesive remnant index (ARI). Statistical analysis included one-way ANOVA with post hoc Tukey HSD and independent sample t -test to compare in vivo bracket debonding force, Cohen’s kappa ( κ ), and a nonparametric Kruskal-Wallis test for the reliability and the assessment of ARI scoring. Results. A significant difference ( p < 0.001 ) of mean debonding force was found between different types of teeth in vivo. Clinically, ARI scores were not significantly different ( p = 0.921 ) between different groups, but overall higher scores were predominant. Conclusion. Bracket debonding force should be measured on the same tooth from the same arch as the significant difference of mean debonding force exists between similar teeth of the upper and lower arches. The insignificant bracket failure pattern with higher ARI scores confirms less enamel damage irrespective of tooth types.

scholarly journals Generational motivation and preference for reward and recognition

2015 ◽  
Vol 4 (3) ◽  
pp. 259-270
Author(s):  
Donné Close ◽  
Nico Martins
Keyword(s):  
South African ◽  
Measuring Instruments ◽  
Reward Structure ◽  
Facilities Management ◽  
Flexible Approach ◽  
Different Types ◽  
The One ◽  
Reward And Recognition ◽  
Post Hoc ◽  
One Way Anova

Generation sub-groups have been and continue to be stereotyped as requiring different approaches in the workplace and elsewhere with regard to what keeps them motivated and satisfied. Two measuring instruments were distributed electronically to all staff of a South African Facilities Management firm. The one-way ANOVA was conducted with post-hoc tests to establish which factors display statistically significant differences between generations. The findings demonstrated that certain generation sub-groups have preferences for different types of reward, reward categories, and have different perceptions about what types of reward attracts, motivates and retains employees. The main recommendation is that the company needs to adopt a flexible approach to reward and recognition that allows employees to tailor their reward structure to their own needs.

scholarly journals Bulk-Fill Direct Restorative Materials: An In Vitro Assessment of Their Physio-Mechanical Properties

Oral ◽  
2021 ◽  
Vol 1 (2) ◽  
pp. 75-87
Author(s):  
Hui Woon Yeo ◽  
May Yeh Loo ◽  
Mariam Alkhabaz ◽  
Kai Chun Li ◽  
Joanne Jung Eun Choi ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Wear Testing ◽  
Restorative Materials ◽  
Different Depths ◽  
Bonferroni Test ◽  
In Vitro Assessment ◽  
High Level ◽  
Post Hoc ◽  
One Way Anova

Bulk-fill restorative material has gained popularity in clinical practice, due to their perceived timesaving aspect. Objective was to compare the properties of bulk-fill direct restorative materials. Filtek Z350 (CR), Filtek One Bulk Fill Restorative (BF), Fuji IX and EQUIA Forte (EF) were compared. Thirty specimens from each material were prepared according to ISO 4049 for three-point flexural strength. Elastic moduli and hardness (n = 20) were evaluated using nanoindentation. Depth of cure (DC) (n = 20) was measured for BF at three different depths (2, 3, 4 mm) and at two irradiation times (20 and 40 s). Wear testing was carried out for three different periods (3, 6, 12 month(s)). All specimens were stored in 37 °C water for 24 h prior to testing. Results were evaluated using one-way ANOVA followed by a post hoc Bonferroni test (p < 0.05). BF and CR showed a significantly higher flexural strength than other groups (p < 0.05), and the highest Weibull modulus was found in CR. BF showed sufficient DC with at least 85%, at all thicknesses. CR and BF also had a high level of translucency than EF and Fuji IX. Significant differences in flexural strength were found among all materials except between Fuji IX and EF. While all material tested are suitable for use clinically, BF and CR have superior properties than GIC based bulk-fill.

scholarly journals The Influence of Three Different Digital Cement Spacers on the Marginal Gap Adaptation of Zirconia-Reinforced Lithium Silicate Crowns Fabricated by CAD-CAM System

2021 ◽  
Vol 11 (22) ◽  
pp. 10709
Author(s):  
Gil Ben-Izhack ◽  
Asaf Shely ◽  
Sarit Naishlos ◽  
Ari Glikman ◽  
Liad Frishman ◽  
...  
Keyword(s):  
Regions Of Interest ◽  
Lithium Silicate ◽  
Marginal Gap ◽  
Cad Cam ◽  
Monolithic Zirconia ◽  
Bonferroni Test ◽  
Ceramic Crowns ◽  
Post Hoc ◽  
One Way Anova ◽  
Electronic Microscope

Background: This study compared the influence of three different radial spacers (60,90,120 microns) on the marginal gap adaptation by using computer-aided manufacturing (CAD-CAM) for producing monolithic zirconia reinforced lithium silicate (ZLS) ceramic crowns. Methods: A total of 45 abutment acrylic teeth were divided into three groups of different radial spacers (60, 90, and 120 microns). In each group 15 teeth were scanned by Omnicam intra oral scanner and ZLS crowns were ground. For each unit the marginal gap was evaluated at four regions of interest by scanning electronic microscope (SEM). To compare the marginal gap between the three groups a one-way ANOVA with post-hoc Bonferroni test was preformed (α = 0.05). Results: The marginal gap for a 60 microns (162.99 ± 16.25 µm) radial spacer was found significantly higher than 90 (41.85 ± 3.57 µm) and 120 (41.85 ± 5.3 µm) microns radial spacers (p < 0.05). Between 90- and 120-micron radial spacers no difference was obtained. (p < 0.05). Conclusions: A radial spacer of 60 microns showed a significantly higher marginal gap compared to 90 and 120 microns and was not clinically accepted (>120 microns). For both 90 and 120 microns the marginal gap was clinically accepted (<120 microns) with no difference between the groups. The radial spacer which should be optimum for CELTRA® DUO crowns is 90 microns.

scholarly journals A comparative study of biaxial flexural strength and Vickers microhardness of different zirconia materials: Effect of glazing and thermal cycling

2015 ◽  
Vol 18 (2) ◽  
pp. 19 ◽  
Author(s):  
Esra Salihoglu Yener ◽  
Mutlu Ozcan ◽  
Ender Kazazoglu
Keyword(s):  
Flexural Strength ◽  
Thermal Cycling ◽  
Vickers Hardness ◽  
Vickers Microhardness ◽  
Testing Machine ◽  
Clinical Importance ◽  
Zirconia Ceramics ◽  
Biaxial Flexural Strength ◽  
Monolithic Zirconia ◽  
One Way Anova

<p class="western" lang="en-GB" align="left"><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Objective:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">This study evaluated the effect of glazing and thermal cycling on biaxial flexural strength and Vickers hardness of different zirconia core materials. </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Material and </strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Methods: </strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">Disc shaped zirconia specimens (15 mm x </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">1.15 mm</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">) were fabricated out of three systems (ZirkonZahn, Cercon, </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">Ceramill</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">) according to each manufacturer`s instructions. The specimens of each system were randomly divided into initially 2 groups. While half of the specimens were glazed, the other half was left unglazed. Each group was further divided into 4 subgroups to be subjected to thermal cycling (0-control, 1000, 3000, 5000 cycles, 5-55 ºC). Biaxial flexural strength was tested in a universal testing machine (1 mm/min). Another set of unglazed zirconia specimens were made and tested for Vickers microhardness with and without thermocycling (0-control, 1000, 3000, 5000 cycles, 5-55 ºC). Data were statistically analyzed using one-way ANOVA, two-way ANOVA and Tukey’s test (</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">p &lt;</span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"> 0.05). </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Results:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"> In non-aged conditions (11034-1388 MPa), glazing significantly decreased the biaxial flexural strength of all zirconia ceramics (845.65-897.35 MPa) (p = 0.000). While in the non-glazed groups, all thermal cycling regimens significantly decreased the biaxial flexural strength (864-1156 MPa) (p=0.000), in glazed groups thermal cycling did not affect the results (829.4-854.9 MPa) (p = 0.405). Compared to the non-aged group (1414.1 VHN), thermal cycling decreased the Vickers hardness significantly only for Cercon (1365.9 VHN) (p = 0.005). </span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>Conclusion:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"> Glazing decreased the biaxial flexural strength of the zirconia ceramics tested. Unglazed zirconia ceramics were weaker against thermal cycling compared to glazed ones. For monolithic zirconia restorations, this information may have clinical importance.</span></span></p><p class="western" align="justify"><span style="font-family: 'Times New Roman', serif;"><span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>K</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB"><strong>eywords:</strong></span></span><span style="font-family: Arial, sans-serif;"><span lang="en-GB">Biaxial flexural strength; Glazing; Thermal cycling; Vickers microhardness; Zirconia.</span></span></span></span></p>

scholarly journals Pengaruh lama aplikasi bahan remineralisasi casein phosphopeptide amorphous calcium phosphate fluoride (CPP-ACPF) terhadap kekerasan email

2016 ◽  
Vol 2 (3) ◽  
pp. 141 ◽  
Author(s):  
Miftah Wiryani ◽  
Billy Sujatmiko ◽  
Rini Bikarindrasari
Keyword(s):  
Vickers Hardness ◽  
Artificial Saliva ◽  
T Test ◽  
Control Group ◽  
Application Time ◽  
Hardness Tester ◽  
Significant Difference ◽  
Post Hoc ◽  
One Way Anova ◽  
Paired T Test

The effect of application time of CPP-ACPF on enamel hardness. Remineralization process can increase the hardness of enamel due to demineralization process. CPP-ACPF is a material used for enhancing remineralization. However, the application time of CPP-ACPF remain controversial among previous studies. This study was aimed to investigate the effect of various application times of CPP-ACPF on enamel hardness. Thirty premolar teeth were mounted on self cure acrylic resin, and were divided into 5 groups. Demineralization process was performed, and enamel hardness (pre-est) was measured by Vickers Hardness Tester. Remineralization was performed using CPP-ACPF in various application times: 3, 15, 30, 60 minutes, and the control group was only immersed in artificial saliva for 60 minutes, then enamel hardness was measured (posttest). Data were analyzed using paired t-test, one-way ANOVA, and post-hoc Bonferroni. The result of paired t-test showed that all the groups, except the control group, have an increasing enamel hardness that was statistically significant. One-way ANOVA results showed no statistically significant difference among the groups at pretest, but one-way ANOVA results showed statistically significant difference at posttest. Post hoc Bonferroni showed that the significantly difference at posttest occurred between all the treatment groups against the control group, but there were no significant differences between the 3 minutes group to 15 minutes group, between 15 minutes group to 30 minutes group, and between 30 minutes group to 60 minutes group. It was concluded that various application times of CPP-ACPF had an effect on increasing enamel hardness. ABSTRAKProses remineralisasi dapat meningkatkan kekerasan email yang menurun akibat demineralisasi. Bahan remineralisasi yang ideal adalah CPP-ACPF. Terdapat perbedaan lama aplikasi CPP-ACPF dalam berbagai penelitian, selain itu total lama aplikasi yang dibutuhkan CPP-ACPF dalam mekanisme remineralisasi belum diketahui. Penelitian ini dilakukan untuk mengetahui pengaruh lama aplikasi CPP-ACPF terhadap kekerasan email. Tiga puluh mahkota gigi premolar yang ditanam dalam resin akrilik self cure dibagi menjadi lima kelompok, kemudian dilakukan proses demineralisasi. Kekerasan email kemudian diukur menggunakan alat Vickers Hardness Tester. Proses remineralisasi menggunakan CPP-ACPF dilakukan pada masing-masing kelompok dalam berbagai lama aplikasi yaitu 3 menit, 15 menit, 30 menit, 60 menit, serta perendaman dalam saliva buatan selama 60 menit (kontrol). Kekerasan email kemudian diukur kembali (posttest). Data diuji secara statistik menggunakan t-test berpasangan, one-way ANOVA dan post hoc Bonferroni. Hasil paired t-test menunjukkan bahwa seluruh kelompok, kecuali kelompok kontrol, mengalami peningkatan rata-rata kekerasan email secara signifikan. Hasil uji one-way ANOVA pada pretest menunjukkan tidak ada perbedaan kekerasan email yang signifikan. Hasil uji one-way ANOVA pada posttest menunjukkan terdapat perbedaan kekerasan email yang signifikan. Hasil uji post Hoc Bonferroni menunjukkan bahwa terdapat perbedaan kekerasan email yang signifikan pada seluruh kelompok perlakuan terhadap kelompok kontrol, tetapi perbedaan kekerasan email antara kelompok lama aplikasi 3 menit dengan 15 menit, antara lama aplikasi 15 menit dengan 30 menit, serta antara lama aplikasi 30 menit dengan 60 menit tidak menunjukkan perbedaan kekerasan email yang signikan. Kesimpulan penelitian ini adalah berbagai lama aplikasi CPP-ACPF berpengaruh terhadap peningkatan kekerasan email.

scholarly journals AN IN VITRO STUDY TO EVALUATE THE TEAR STRENGTH OF AUTOCLAVABLE PVS, SMART WETTING PVS AND CONDENSATION SILICONE AND COMPARE THEM UPON AUTOCLAVING AND DISINFECTION.

2020 ◽  
pp. 67-70
Author(s):  
Garima Gothwal ◽  
Hemant Kumar Sharma ◽  
Kusum Singh ◽  
Richa Sengar
Keyword(s):  
Statistical Analysis ◽  
Testing Machine ◽  
In Vitro Study ◽  
Tear Strength ◽  
Universal Testing ◽  
Impression Materials ◽  
Different Types ◽  
Post Hoc ◽  
One Way Anova

Aim: The tear strength of three different types of elastomeric impression materials was measured after disinfection and sterilization. Material and Method: Dumb-bell shaped Tear strength specimens were prepared according to ISO 34-1 standardization. Ninety samples were prepared followed by disinfection and sterilization and tested with trouser piece method on Instron universal testing machine at a speed of 10 mm/min. One-way ANOVA, followed by Tukey post hoc test was used for statistical analysis. Results: No signicant difference was found when AFFINIS, SPEEDEX and AQUASIL were compared individually. When materials were compared with each other signicant difference was present, highest AQUASIL while SPEEDEX and AFFINIS almost alike. Conclusion: It was concluded that tear strength of AQUASIL was the highest. Disinfection and autoclaving had no signicant inuence on the three materials and showed adequate tear strength.

scholarly journals Degree of Conversion of a Resin Cement Light-Cured Through Ceramic Veneers of Different Thicknesses and Types

2014 ◽  
Vol 25 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Patrício Runnacles ◽  
Gisele Maria Correr ◽  
Flares Baratto Filho ◽  
Carla Castiglia Gonzaga ◽  
Adilson Yoshio Furuse
Keyword(s):  
Ftir Spectroscopy ◽  
Degree Of Conversion ◽  
Resin Cement ◽  
Resin Cements ◽  
Different Types ◽  
Light Curing ◽  
One Way Anova

During the cementation of ceramic veneers the polymerization of resin cements may be jeopardized if the ceramics attenuate the irradiance of the light-curing device. The aim of this study was to evaluate the effect of different types and thicknesses of ceramic veneers on the degree of conversion of a light-cured resin-based cement (RelyX Veneer). The cement was light-cured after interposing ceramic veneers [IPS InLine, IPS Empress Esthetic, IPS e.max LT (low translucency) and IPS e.max HT (high translucency) - Ivoclar Vivadent] of four thicknesses (0.5 mm, 1.0 mm, 1.5 mm and 2.0 mm). As control, the cement was light-cured without interposition of ceramics. The degree of conversion was evaluated by FTIR spectroscopy (n=5). Data were analyzed with one-way ANOVA and Tukey's test (α=0.05). Significant differences were observed among groups (p<0.001). The degree of conversion was similar to the control for all light-cured groups with interposition of ceramics of 0.5 mm and 1.0 mm (p>0.05). Among 1.5-mm-thick veneers, IPS e.max LT was the only one that showed different results from the control (p<0.05). At the thickness of 2.0 mm, only the IPS e.max LT and HT veneers were able to produce cements with degrees of conversion similar to the control (p>0.05). The degree of conversion of the evaluated light-cured resin cement depends on the thickness and type of ceramics employed when veneers thicker than 1.5 mm are cemented.

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