Effect of photo-polymerization mode on the degree of conversion of resin cement under different ceramic materials

SUMMARY This study investigated the effects of irradiance and exposure duration on dual-cured resin cements irradiated through ceramic restorative materials. A single light-curing unit was calibrated to three different irradiances (500, 1000, and 1500 mW/cm2) and irradiated to three different attenuating materials (transparent acryl, lithium disilicate, zirconia) with 1-mm thicknesses for 20 or 60 seconds. The changes in irradiance and temperature were measured with a radiometer (or digital thermometer) under the attenuating materials. The degree of conversion (DC) of dual-cure resin cement after irradiation at different irradiances and exposure durations was measured with Fourier transform near infrared spectroscopy. Two-way analysis of variance revealed that irradiance (p<0.001) and exposure duration (p<0.001) significantly affected temperature and DC. All groups showed higher DCs with increased exposure times (p<0.05), but there were no statistically significant differences between the groups irradiated with 1000 mW/cm2 and 1500 mW/cm2 (p>0.05). Higher-intensity irradiances yielded higher temperatures (p<0.05), but exposure time did not affect temperature when materials were irradiated at 500 mW/cm2 (p>0.05).

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Lack of Neutralization of 10-MDP Primers by Zirconia May Affect the Degree of Conversion of Dual-cure Resin Cement

Operative Dentistry ◽

10.2341/18-189-l ◽

2021 ◽

Vol 46 (1) ◽

pp. 107-115

Author(s):

DM De Paula ◽

AD Loguercio ◽

A Reis ◽

S Sauro ◽

AH Alves ◽

...

Keyword(s):

Bond Strength ◽

Testing Machine ◽

Monomer Concentration ◽

Positive Control ◽

Degree Of Conversion ◽

Resin Cement ◽

Dihydrogen Phosphate ◽

Resin Cements ◽

Low Concentrations ◽

Microshear Bond Strength

Clinical Relevance Use of zirconia primers with a low pH and a high acidic monomer concentration should be employed in combination with dual-cure resin cements that are less sensitive to an acidic environment. Primers with lower 10-MDP concentrations attain better outcomes. SUMMARY Objective: To assess the effects of different concentrations of 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) included in experimental ceramic primers on the degree of conversion (DC) and microshear bond strength (μSBS) of a dual-cure resin cement, and on the acidity neutralization potential of zirconia (ZrO2) in comparison to hydroxyapatite (HAp). Methods: Experimental ceramic primers were formulated using 5 wt%, 10 wt%, 20 wt%, or 40 wt% 10-MDP as an acidic functional monomer and camphorquinone (CQ)/amine or 1-phenyl-1,2-propanedione (PPD) as a photoinitiator system. Clearfil Ceramic Primer (Kuraray Dental, Tokyo, Japan) was used as the commercial control. Micro-Raman spectroscopy was used to assess the DC of uncured and light-cured resin cements applied onto primer-treated ZrO2 surfaces. The μSBS and pH of primers were assayed in a universal testing machine and by a digital pH meter (Tec-3MP; Tecnal, Piracicaba, Brazil), respectively. Statistical analysis was performed by one-way analysis of variance (ANOVA) and Tukey’s test (p<0.05). Results: DC was not affected until a concentration of 10% 10-MDP in CQ primer and 5% 10-MDP in PPD primer was reached, when compared with the positive control (p>0.05). Groups 10-MDP 5% in CQ and PPD primers showed the highest μSBS compared with the positive control (p>0.05); however, higher concentrations of 10-MDP induced significant DC and μSBS reduction (p<0.05). HAp neutralized 10-MDP primers, but ZrO2 provided higher acidity to the primers’ pH. Conclusion: 10-MDP monomer should be used in low concentrations in ZrO2 primers to avoid reduction of the polymerization and bond strength of resin cement.

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Color stability and degree of conversion of a novel dibenzoyl germanium derivative containing photo-polymerized resin luting cement

Journal of Applied Biomaterials & Functional Materials ◽

10.1177/2280800020917326 ◽

2020 ◽

Vol 18 ◽

pp. 228080002091732 ◽

Cited By ~ 1

Author(s):

Fahad Alkhudhairy ◽

Fahim Vohra ◽

Mustafa Naseem ◽

Mosa Mohammed Owais ◽

Abdulmajeed H Bin Amer ◽

...

Keyword(s):

Color Stability ◽

Color Difference ◽

Degree Of Conversion ◽

Resin Cement ◽

Resin Cements ◽

Luting Agents ◽

Multiple Comparison Test ◽

Luting Cement ◽

Color Components

Aim: To compare the color stability and degree of conversion (DC) of a resin cement containing a dibenzoyl germanium derivative photo-initiator (Variolink Esthetic) to resin cements containing conventional luting agents. Materials and Method: Spectrophotometry and Fourier transform infrared spectroscopy (FTIR) were used to compare the color stability and DC, respectively, of Variolink Esthetic compared to Calibra, Variolink-N, and NX3 resin cements. Ten specimens (1 × 2 mm2) of each resin cement were photo-polymerized and then subjected to color stability assessments. In addition, 30 samples of each of the four resin cements were prepared and then immersed in three staining solutions (tea, coffee, and distilled water) for two weeks. Changes in color for the immersed versus non-immersed specimens (control specimens) were determined by comparing ΔL (lightness), Δa, and Δb (color components), and an overall ΔE (color difference) obtained from spectrophotometry assays. One-way analysis of variance and a multiple comparison test (Tukey’s test) were used to analyze color stability and DC data. NX3 and Variolink Esthetic resin cements exhibited significantly lower values compared to the dual cured resin cements (Variolink-N and Calibra). Results: The highest DC values were observed among the photo-polymerized samples of Variolink Esthetic (87.18 ± 2.90%), while the lowest DC values were observed among the Variolink-N samples (44.55 ± 4.33%). Conclusion: The resin cement, Variolink Esthetic, containing a novel dibenzoyl germanium derivative photo-initiator exhibited superior color stability ( p < 0.05) and a higher DC than other resin cements containing conventional luting agents in an in vitro setting.

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Degree of conversion and surface hardness of resin cement cured with different curing units

Journal of Prosthetic Dentistry ◽

10.1016/j.prosdent.2006.03.009 ◽

2006 ◽

Vol 96 (2) ◽

pp. 128 ◽

Cited By ~ 1

Author(s):

N. Ozturk ◽

A. Usumez ◽

S. Usumez ◽

B. Ozturk

Keyword(s):

Surface Hardness ◽

Degree Of Conversion ◽

Resin Cement

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Indirect Restoration Thickness and Time after Light-Activation Effects on Degree of Conversion of Resin Cement

Brazilian Dental Journal ◽

10.1590/0103-64402013x0024 ◽

2015 ◽

Vol 26 (4) ◽

pp. 363-367 ◽

Cited By ~ 7

Author(s):

Ana Paula Almeida Ayres ◽

Carolina Bosso Andre ◽

Rafael Rocha Pacheco ◽

Adriana Oliveira Carvalho ◽

Renata Cantanhede Bacelar-Sá ◽

...

Keyword(s):

Light Exposure ◽

Degree Of Conversion ◽

Resin Cement ◽

The Self ◽

Diamond Surface ◽

Light Activation ◽

Curing Conditions ◽

Direct Light ◽

Restorative Materials ◽

Post Hoc

<p>This study evaluated the effects of indirect restorative materials, curing conditions and time on the degree of conversion (DC) of a dual-cured resin cement using infrared spectroscopy. The resin cement (RelyX Unicem 2, 3M ESPE) was applied to the diamond surface of a horizontal attenuated-total-reflectance unit and activated using one of following conditions: self-cure, direct light exposure, light exposure through indirect restorative materials (resin nano-ceramic: Lava Ultimate, 3M ESPE or feldspathic ceramic: Vita Blocks Mark II, Vita Zahnfabrik). Four thicknesses (0.5, 1.0, 1.5 or 2.0 mm) of each indirect material were analyzed, and the light-activation was performed using a blue LED light. Data (n=5) were analyzed by three-way ANOVA, Tukey's post hoc and Dunnett's tests (α=5%). No significant differences in DC were observed between indirect materials of similar thickness. All groups exhibited higher DC after 10 min than after 5 min. At both times points, the self-cure group exhibited significantly lower DC than all the light exposure groups. Only when the overlying indirect restoration had a thickness of 2 mm did DC decrease significantly. The presence of a thick, indirect restoration can decrease the DC of resin cement. DC after 10 min was higher than after 5 min. The self-cure mode yielded lower DC than the light-activating one.</p>

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Degree of conversion of dual-cured resin cement light-cured through three fibre posts within human root canals: anex vivostudy

International Endodontic Journal ◽

10.1111/j.1365-2591.2009.01565.x ◽

2009 ◽

Vol 42 (8) ◽

pp. 667-674 ◽

Cited By ~ 29

Author(s):

Y. K. Kim ◽

S. K. Kim ◽

K. H. Kim ◽

T. Y. Kwon

Keyword(s):

Degree Of Conversion ◽

Resin Cement ◽

Root Canals

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Effect of Different Thicknesses of Pressable Ceramic Veneers on Polymerization of Light-cured and Dual-cured Resin Cements

The Journal of Contemporary Dental Practice ◽

10.5005/jp-journals-10024-1688 ◽

2015 ◽

Vol 16 (5) ◽

pp. 347-352 ◽

Cited By ~ 10

Author(s):

Seok-Hwan Cho ◽

Arnaldo Lopez ◽

David W Berzins ◽

Soni Prasad ◽

Kwang Woo Ahn

Keyword(s):

Light Intensity ◽

Vickers Microhardness ◽

Storage Period ◽

Degree Of Conversion ◽

Resin Cement ◽

Cement Type ◽

Resin Cements ◽

Significant Difference ◽

Ceramic Disk ◽

Ceramic Thickness

ABSTRACT Aim This study evaluated the effects of ceramic veneer thicknesses on the polymerization of two different resin cements. Materials and methods A total of 80 ceramic veneer disks were fabricated by using a pressable ceramic material (e.max Press; Ivoclar Vivadent) from a Low Translucency (LT) ingot (A1 shade). These disks were divided into light-cured (LC; NX3 Nexus LC; Kerr) and dual-cured (DC; NX3 Nexus DC; Kerr) and each group was further divided into four subgroups, based on ceramic disk thickness (0.3, 0.6, 0.9, and 1.2 mm). The values of Vickers microhardness (MH) and degree of conversion (DOC) were obtained for each specimen after a 24-hour storage period. Association between ceramic thickness, resin cement type, and light intensity readings (mW/cm2) with respect to microhardness and degree of conversion was statistically evaluated by using analysis of variance (ANOVA). Results For the DOC values, there was no significant difference observed among the LC resin cement subgroups, except in the 1.2 mm subgroup; only the DOC value (14.0 ± 7.4%) of 1.2 mm DC resin cement had significantly difference from that value (28.9 ± 7.5%) of 1.2 mm LC resin cement (p < 0.05). For the MH values between LC and DC resin cement groups, there was statistically significant difference (p < 0.05); overall, the MH values of LC resin cement groups demonstrated higher values than DC resin cement groups. On the other hands, among the DC resin cement subgroups, the MH values of 1.2 mm DC subgroup was significantly lower than the 0.3 mm and 0.6 mm subgroups (p < 0.05). However, among the LC subgroups, there was no statistically significant difference among them (p > 0.05). Conclusion The degree of conversion and hardness of the resin cement was unaffected with veneering thicknesses between 0.3 and 0.9 mm. However, the DC resin cement group resulted in a significantly lower DOC and MH values for the 1.2 mm subgroup. Clinical Significance While clinically adequate polymerization of LC resin cement can be achieved with a maximum 1.2 mm of porcelain veneer restoration, the increase of curing time or light intensity is clinically needed for DC resin cements at the thickness of more than 0.9 mm. How to cite this article Cho S-H, Lopez A, Berzins DW, Prasad S, Ahn KW. Effect of Different Thicknesses of Pressable Ceramic Veneers on Polymerization of Lightcured and Dual-cured Resin Cements. J Contemp Dent Pract 2015;16(5):347-352.

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