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Wang L, Ku H, Kim D, Park SH. Effect of shade and thickness on the microhardness of resin-based composite specimens at different points considering curing light beam's inhomogeneity. BMC Oral Health 2024; 24:865. [PMID: 39080607 PMCID: PMC11290111 DOI: 10.1186/s12903-024-04647-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 07/23/2024] [Indexed: 08/02/2024] Open
Abstract
BACKGROUND Recent studies have reported the inhomogeneity in the light emitted by dental light-curing units (LCUs). It is essential to understand how this uneven light distribution affects the physical properties of resin-based composites (RBCs) at various points across their surfaces. This study aimed to evaluate the effect of LCU beam's inhomogeneity on the microhardness of RBCs with different shades and thicknesses. METHODS Four body (A1B, A2B, A3B, and A4B), one dentin (A3D), and one enamel shade (A3E) of RBC (Filtek Z350 XT) were examined. The specimens were fabricated in four thicknesses (1, 2, 3, and 4 mm) and subjected to a 40-second light-curing. Vickers microhardness testing was performed at the center point, and 3 mm left and right from the center at the bottom surface of each sample. The LCU beam profile was characterized using a beam profiler, while irradiance after specimen passage was measured using a spectrometer. One-way analysis of variance (ANOVA) and Tukey's post-hoc tests were used to analyze the effects of shades and thicknesses on irradiance and microhardness, respectively. One-way repeated-measures ANOVA was used to compare the microhardness across different points. Pearson's correlation analysis examined the relationship between irradiance and microhardness. RESULTS The beam profile of LCU revealed inhomogeneous light distribution. Light irradiance was decreased with both the increase in thickness and darker shade of the specimens (p < 0.05). Microhardness was found to decline with an increase in sample thickness (p < 0.05), and was consistently higher at the center point compared to the periphery, particularly in thicker (3 and 4 mm) and darker shades (A3B, A4B, and A3D). A positive correlation was found between the irradiance and microhardness across all evaluated points (p < 0.05). CONCLUSIONS Inhomogeneous light emission from LCU significantly influences the microhardness of RBC samples, depending on the thicknesses and shades. The findings underline the importance of considering LCU beam inhomogeneity in clinical settings to ensure optimal polymerization of RBC.
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Affiliation(s)
- Lan Wang
- Department of Conservative Dentistry and Oral Science Research Center, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Hyemin Ku
- Department of Conservative Dentistry and Oral Science Research Center, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea
| | - Dohyun Kim
- Department of Conservative Dentistry and Oral Science Research Center, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
| | - Sung-Ho Park
- Department of Conservative Dentistry and Oral Science Research Center, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
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Haralur SB, Alasmari TA, Alasmari MH, Hakami HM. Light Transmission of Various Aesthetic Posts at Different Depths and Its Effect on Push-Out Bond Strength, Microhardness of Luting Cement. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58010075. [PMID: 35056383 PMCID: PMC8780944 DOI: 10.3390/medicina58010075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 12/23/2021] [Accepted: 12/27/2021] [Indexed: 11/16/2022]
Abstract
Background and Objectives: One requirement for the cemented post is the light transmittance on its entire length up to the deepest portion of a root canal to ensure the complete polymerization of resin cement. This study aimed to determine the light transmission ability in different aesthetic posts at different depths and its effect on the push-out bond strength and microhardness of luting cement at the corresponding interface. Materials and Methods: Twenty endodontic posts from glass fiber posts (GFP), zirconia ceramic posts (ZCP), and highly translucent zirconium oxide posts (HTZP) were sequentially sectioned into 12.8 and 4 mm lengths after recording the light intensity using a dental radiometer. Sixty single rooted premolar teeth root canals were treated and implanted vertically in a resin block. The post space was prepared and cemented with GFP, ZCP, and HTZP posts with twenty samples each. The root portion of teeth samples were sectioned into cervical, middle, and apical portion. A universal testing machine was utilized for the push-out bond strength test for the first ten samples from each group. The remaining ten samples from each group were used for the microhardness test using a micro-indenter instrument. The data were statistically analyzed using one-way Analysis of variance and Tukey HSD tests at p < 0.05. Results: The GFP endodontic postpresented with significant highest light translucency compared to HTZP, which was significantly higher than ZCP. GFP posts showed significantly higher bond strength per unit area compared to ZCP at analogous cross sections. The hardness of luting cement was also significantly higher amongst all tested endodontic posts. Conclusions: GFP high light translucency enhanced the curing of the luting resin cement that resulted in harder cement and a stronger bond supported by hardness and push-out tests. These findings suggest that GFP is preferred to be used with light-cured luting cements for restoration of endodontically treated teeth.
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Affiliation(s)
- Satheesh B. Haralur
- Department of Prosthodontics, College of Dentistry, King Khalid University, Abha 62529, Saudi Arabia
- Correspondence: ; Tel.: +96-6555-835386
| | - Turki Abdullah Alasmari
- College of Dentistry, King Khalid University, Abha 62529, Saudi Arabia; (T.A.A.); (M.H.A.); (H.M.H.)
| | - Mohammed Hussin Alasmari
- College of Dentistry, King Khalid University, Abha 62529, Saudi Arabia; (T.A.A.); (M.H.A.); (H.M.H.)
| | - Hafiz Mohammed Hakami
- College of Dentistry, King Khalid University, Abha 62529, Saudi Arabia; (T.A.A.); (M.H.A.); (H.M.H.)
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De Angelis F, Vadini M, Capogreco M, D’Arcangelo C, D’Amario M. Effect of Light-Sources and Thicknesses of Composite Onlays on Micro-Hardness of Luting Composites. MATERIALS 2021; 14:ma14226849. [PMID: 34832251 PMCID: PMC8618162 DOI: 10.3390/ma14226849] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/10/2021] [Accepted: 11/11/2021] [Indexed: 11/18/2022]
Abstract
The aim of this study was to compare three different light-curing-units (LCUs) and determine their effectiveness in the adhesive cementation of indirect composite restorations when a light-curing resin cement is used. Two resin composites were selected: Enamel Plus HRI (Micerium) and AURA (SDI). Three thicknesses (3 mm, 4 mm and 5 mm) were produced and applied as overlays and underlays for each resin composite. A standardized composite layer was placed between underlay and overlay surfaces. Light curing of the resin-based luting composites was attained through the overlay filters using LCUs for different exposure times. All specimens were allocated to experimental groups according to the overlay thickness, curing unit and curing time. Vickers Hardness (VH) notches were carried out on each specimen. Data were statistically evaluated. The curing unit, curing time and overlay thickness were significant factors capable of influencing VH values. The results showed significantly decreased VH values with increasing specimen thickness (p < 0.05). Significant differences in VH values were found amongst the LCUs for the various exposure times (p < 0.05). According to the results, a time of cure shorter than 80 s (with a conventional quartz–tungsten–halogen LCU) or shorter than 40 s (with a high-power light-emitting diode (LED) LCU) is not recommended. The only subgroup achieving clinically acceptable VH values after a short 20 s curing time included the 3 mm-thick overlays made out of the AURA composite, when the high-power LED LCU unit was used (VH 51.0). Composite thickness has an intense effect on polymerization. In clinical practice, light-cured resin cements may result in insufficient polymerization for high thickness and inadequate times. High-intensity curing lights can attain the sufficient polymerization of resin cements through overlays in a significantly shorter time than conventional halogen light.
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Affiliation(s)
- Francesco De Angelis
- Unit of Restorative Dentistry and Endodontics, Department of Medical, Oral and Biotechnological Sciences, Dental School, “G. D’Annunzio” University of Chieti, 66100 Chieti, Italy; (F.D.A.); (C.D.)
| | - Mirco Vadini
- Unit of Restorative Dentistry and Endodontics, Department of Medical, Oral and Biotechnological Sciences, Dental School, “G. D’Annunzio” University of Chieti, 66100 Chieti, Italy; (F.D.A.); (C.D.)
- Correspondence:
| | - Mario Capogreco
- Unit of Restorative Dentistry, Endodontics and Oral Pathology, Dental Clinic, Department of Life, Health and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, Italy; (M.C.); (M.D.)
| | - Camillo D’Arcangelo
- Unit of Restorative Dentistry and Endodontics, Department of Medical, Oral and Biotechnological Sciences, Dental School, “G. D’Annunzio” University of Chieti, 66100 Chieti, Italy; (F.D.A.); (C.D.)
| | - Maurizio D’Amario
- Unit of Restorative Dentistry, Endodontics and Oral Pathology, Dental Clinic, Department of Life, Health and Environmental Sciences, University of L’Aquila, 67100 L’Aquila, Italy; (M.C.); (M.D.)
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Pechteewang S, Salimee P. Microhardness of resin cements after light activation through various translucencies of monolithic zirconia. J Adv Prosthodont 2021; 13:246-257. [PMID: 34504676 PMCID: PMC8410305 DOI: 10.4047/jap.2021.13.4.246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 08/13/2021] [Accepted: 08/20/2021] [Indexed: 11/26/2022] Open
Abstract
PURPOSE This study aimed to investigate the Vickers Hardness Number (VHN) of light- and dual cured resin cements cured through monolithic zirconia specimens (VITA YZ) of various translucencies: translucent (T); high translucent (HT); super translucent (ST); and extra translucent (XT) at 0, 24, and 48 h after curing. MATERIALS AND METHODS Four zirconia specimens from each translucency were prepared. Two light-cured resin cements (Variolink N LC; VL and RelyX Veneer; RL) and two dual-cured resin cements (Variolink N DC; VD and RelyX U200; RD) were used. The cement was mixed and loaded in a mold and cured for 20 s through the zirconia specimen. The upper surface of cements was tested for VHN using a microhardness tester at 0, 24, and 48 h after curing. The VHN were analyzed using two-way repeated, Brown-Forsythe ANOVA with Games Howell post-hoc analysis and independent t-tests (P < .05). RESULTS All cements showed significantly higher VHN from 0 h to 24 h (P < .001). At 48 h, the VHN of light-cured cements were significantly lower when cured under the T groups than under XT groups (P = .001 in VL, P = .014 in RL). At each post curing time of each translucency, VD showed higher VHN than VL (P < .05), and RD also showed higher VHN than RL (P < .05). CONCLUSION The translucency of zirconia has an effect on the VHN for light-cured resin cements, but has no effect on dual-cured resin cements. Dual-cured resin cement exhibited higher VHN than the light-cured resin cement from the same manufacturer. All resin cements showed significantly higher VHN from 0 h to 24 h.
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Affiliation(s)
- Sawanya Pechteewang
- Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Prarom Salimee
- Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
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Borges LPS, Borges GA, Correr AB, Platt JA, Kina S, Correr-Sobrinho L, Costa AR. Effect of lithium disilicate ceramic thickness, shade and translucency on transmitted irradiance and knoop microhardness of a light cured luting resin cement. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2021; 32:90. [PMID: 34338911 PMCID: PMC8328902 DOI: 10.1007/s10856-021-06562-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 07/13/2021] [Indexed: 06/02/2023]
Abstract
This in vitro study evaluates the influence of pressed lithium disilicate thickness, shade and translucency on the transmitted irradiance and the Knoop microhardness (KHN) of a light-cured resin cement at two depths. One hundred and thirty-five ceramic discs of IPS e.max Press (Ivoclar Vivadent) were fabricated and divided into twenty-seven groups (n = 5) according to the association between translucency: HT (hight translucency), LT (low translucency), and MO (medium opacity); shade: BL2, A1 and A3.5; and thickness: 0.5 mm, 1.5 mm, and 2.0 mm. One side of each ceramic disc was finished, polished and glazed. The irradiance (mW/cm²) of a multiwave LED light curing unit (Valo, Ultradent) was evaluated with a potentiometer (Ophir 10ª-V2-SH, Ophir Optronics) without (control group) or with interposition of ceramic samples. The microhardness of Variolink Esthetic LC resin cement (Ivoclar Vivadent) was evaluated after 24 h at two depths (100 μm and 700 μm). Data were submitted to ANOVA followed by Tukey's test (α = 0.05). Irradiance and KHN were significantly influenced by ceramic thickness (p < 0.0001), shade (p < 0.001), translucency (p < 0.0001) and depth (p < 0.0001). Conclusions: the interposition of increasing ceramic thicknesses significantly reduced the irradiance and microhardness of resin cement. Increased depth in the resin cement showed significantly reduced microhardness for all studied groups. Increased ceramic opacity reduced the KHN of the resin cement at both depths for all ceramic thicknesses and shades.
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Affiliation(s)
- Lincoln Pires Silva Borges
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, SP, Brazil
| | - Gilberto Antônio Borges
- Department of Dental Materials and Restorative Dentistry, University of Uberaba, Uberaba, MG, Brazil
| | - Américo Bortolazzo Correr
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, SP, Brazil
| | - Jeffrey A Platt
- Associate Professor of Dental Materials, Indiana University School of Dentistry, Indianapolis, IN, USA
| | - Sidney Kina
- Associate Professor, Kina Essential Balance Institute, Maringá, PR, Brazil
| | - Lourenço Correr-Sobrinho
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, SP, Brazil
| | - Ana Rosa Costa
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, State University of Campinas - UNICAMP, Piracicaba, SP, Brazil.
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Evaluation of Dual-Cure Resin Cement Polymerization under Different Types and Thicknesses of Monolithic Zirconia. BIOMED RESEARCH INTERNATIONAL 2019; 2019:4567854. [PMID: 30729124 PMCID: PMC6343131 DOI: 10.1155/2019/4567854] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 12/26/2018] [Indexed: 02/04/2023]
Abstract
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.
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Turp V, Turkoglu P, Sen D. Influence of monolithic lithium disilicate and zirconia thickness on polymerization efficiency of dual-cure resin cements. J ESTHET RESTOR DENT 2018; 30:360-368. [DOI: 10.1111/jerd.12390] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2018] [Revised: 04/24/2018] [Accepted: 04/25/2018] [Indexed: 02/04/2023]
Affiliation(s)
- Volkan Turp
- Department of Prosthodontics; Istanbul University; Istanbul Turkey
| | - Pinar Turkoglu
- Department of Prosthodontics; Istanbul University; Istanbul Turkey
| | - Deniz Sen
- Department of Prosthodontics; Istanbul University; Istanbul Turkey
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Moreno MBP, Costa AR, Rueggeberg FA, Correr AB, Sinhoreti MAC, Ambrosano GMB, Consani S, Correr L. Effect of Ceramic Interposition and Post-activation Times on Knoop Hardness of Different Shades of Resin Cement. Braz Dent J 2018; 29:76-81. [PMID: 29267529 DOI: 10.1590/0103-6440201801635] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 08/02/2017] [Indexed: 11/22/2022] Open
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.
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Affiliation(s)
- Marina Barrêto Pereira Moreno
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Ana Rosa Costa
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Frederick Allen Rueggeberg
- Department of Oral Rehabilitation, Section of Dental Materials, Dental College of Georgia, Augusta University, Augusta, GA, USA
| | - Américo Bortolazzo Correr
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Mário Alexandre Coelho Sinhoreti
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Gláucia Maria Bovi Ambrosano
- Department of Community Dentistry, Statistics Division, Piracicaba Dental School, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Simonides Consani
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Lourenço Correr
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
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Influence of polymerization time on properties of dual-curing cements in combination with high translucency monolithic zirconia. J Prosthodont Res 2018; 62:468-472. [PMID: 29983378 DOI: 10.1016/j.jpor.2018.06.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 06/05/2018] [Accepted: 06/10/2018] [Indexed: 11/27/2022]
Abstract
PURPOSE The aim of this in vitro study was to assess conversion degree (DC), micro-hardness (MH) and bond strength of two dual-curing resin cements employed under translucent monolithic zirconia irradiated with different time protocols. METHODS 84 square shaped samples of 1mm thickness were prepared from high translucency zirconia blocks and divided into two groups (n=24) according to the cement employed: (1) Rely-X Ultimate; (2) Panavia SA. Each group was further divided into 3 subgroups (n=8) according to the irradiation time: (a) no light; (b) 20s; (c) 120s. Light curing was performed 60s after the sample was placed on the diamond support of a FT-IR spectrophotometer with a high power multiLED lamp. Final DC% were calculated after 10min. After 24h, Vickers Test on the cement layer was performed. The same protocol was used to lute composite cylinders in order to evaluate microshear bond-strength test. ANOVA and Bonferroni tests were performed to find differences between MH and bond-strength to zirconia, while for DC% the Scheirer-Ray-Hare two-way test was used. RESULTS The two cements reached higher DC% in subgroup (b) and (c). As concern MH, statistics showed an increase in curing time was able to improve MH significantly. Bond-strength was not affected by irradiation time only for Panavia SA. CONCLUSIONS The first null hypothesis has to be rejected since DC% and MH of the dual-cements tested were influenced by the curing time. The second null hypothesis is partially rejected since the bond strength was influenced by the curing time only for Rely-X Ultimate.
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AlShaafi MM. Factors affecting polymerization of resin-based composites: A literature review. Saudi Dent J 2017; 29:48-58. [PMID: 28490843 PMCID: PMC5411902 DOI: 10.1016/j.sdentj.2017.01.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/28/2017] [Accepted: 01/29/2017] [Indexed: 11/15/2022] Open
Abstract
AIM The aim of this review was to help clinicians improve their understanding of the polymerization process for resin-based composites (RBC), the effects of different factors on the process and the way in which, when controlled, the process leads to adequately cured RBC restorations. METHODS Ten factors and their possible effects on RBC polymerization are reviewed and discussed, with some recommendations to improve that process. These factors include RBC shades, their light curing duration, increment thickness, light unit system used, cavity diameter, cavity location, light curing tip distance from the curing RBC surface, substrate through which the light is cured, filler type, and resin/oral cavity temperature. CONCLUSION The results of the review will guide clinicians toward the best means of providing their patients with successfully cured RBC restorations.
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Affiliation(s)
- Maan M AlShaafi
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
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11
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Okulus Z, Buchwald T, Voelkel A. Characterization of light-cured, dental-resin-based biocomposites. J Appl Polym Sci 2015. [DOI: 10.1002/app.42812] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Zuzanna Okulus
- Institute of Chemical Technology and Engineering; Poznań University of Technology; ul. Berdychowo 4 60-965 Poznań Poland
| | - Tomasz Buchwald
- Faculty of Technical Physics; Poznań University of Technology; ul. Piotrowo 3 60-965 Poznań Poland
| | - Adam Voelkel
- Institute of Chemical Technology and Engineering; Poznań University of Technology; ul. Berdychowo 4 60-965 Poznań Poland
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12
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Gultekin P, Pak Tunc E, Ongul D, Turp V, Bultan O, Karataslı B. Curing efficiency of dual-cure resin cement under zirconia with two different light curing units. J Istanb Univ Fac Dent 2015; 49:8-16. [PMID: 28955530 PMCID: PMC5573479 DOI: 10.17096/jiufd.97059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Accepted: 02/09/2015] [Indexed: 11/19/2022] Open
Abstract
Purpose: Adequate polymerization is a crucial factor in obtaining optimal physical properties and a satisfying
clinical performance from composite resin materials. The aim of this study was to evaluate the polymerization efficiency of
dual-cure resin cement cured with two different light curing units under zirconia structures having differing thicknesses. Materials and Methods: 4 zirconia discs framework in 4 mm diameter and in 0.5 mm, 1 mm and 1.5 mm thickness
were prepared using computer-aided design system. One of the 0.5 mm-thick substructures was left as mono-layered
whereas others were layered with feldspathic porcelain of same thickness and ceramic samples with 4 different
thicknesses (0.5, 1, 1.5 and 2.0 mm) were prepared. For each group (n=12) resin cement was light cured in
polytetrafluoroethylene molds using Light Emitting Diode (LED) or Quartz-Tungsten Halogen (QHT) light curing
units under each of 4 zirconia based discs (n=96). The values of depth of cure (in mm) and the Vickers Hardness
Number values (VHN) were evaluated for each specimen. Results: The use of LED curing unit produced a greater depth of cure compared to QTH under ceramic discs
with 0.5 and 1 mm thickness (p<0.05).At 100μm and 300 μm depth, the LED unit produced significantly greater
VHN values compared to the QTH unit (p<0.05). At 500 μm depth, the difference between the VHN values of
LED and QTH groups were not statistically significant. Conclusion: Light curing may not result in adequate resin cement polymerization under thick zirconia structures.
LED light sources should be preferred over QTH for curing dual-cure resin cements, especially for those under thicker zirconia restorations.
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Affiliation(s)
- Pınar Gultekin
- Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Turkey
| | - Elif Pak Tunc
- Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Turkey
| | - Deger Ongul
- Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Turkey
| | - Volkan Turp
- Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Turkey
| | - Ozgur Bultan
- Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Turkey
| | - Burcin Karataslı
- Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Turkey
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13
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Hardness gradients of dual-polymerized flowable composite resins in simulated root canals. J Prosthet Dent 2014; 112:1231-7. [DOI: 10.1016/j.prosdent.2014.03.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Revised: 03/28/2014] [Accepted: 03/29/2014] [Indexed: 11/16/2022]
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14
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Münchow EA, Valente LL, Peralta SL, Fernández MR, Lima GDS, Petzhold CL, Piva E, Ogliari FA. 1,3-Diethyl-2-thiobarbituric acid as an alternative coinitiator for acidic photopolymerizable dental materials. J Biomed Mater Res B Appl Biomater 2013; 101:1217-21. [PMID: 23564499 DOI: 10.1002/jbm.b.32933] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 01/10/2013] [Accepted: 02/17/2013] [Indexed: 11/09/2022]
Abstract
The ethyl-4-dimethylaminobenzoate (EDAB) is widely used as a coinitiator of the camphorquinone (CQ), but in acidic circumstances it might present some instability, reducing the polymerization efficiency of the material. Considering this, new coinitiators are being evaluated. Hence, this study evaluated the kinetic of polymerization (KP), the degree of conversion (DC), and the rate of polymerization (RP ) of experimental resin adhesives containing 1,3-diethyl-2-thiobarbituric acid (TBA) as a coinitiator of the CQ. The experimental monomeric blend was prepared with bisphenol A glycidyl dimethacrylate, 2-hydroxyethyl methacrylate, and acidic monomers. CQ was added at 1 mol % as photoinitiator. Six groups were formulated: four containing concentrations of 0.1, 0.5, 1, and 2 mol % of TBA, one without coinitiator, and the last one containing 1 mol % of EDAB (control group). The KP and the RP were performed using real-time Fourier Transform infrared spectroscopy. The group without coinitiator has not formed a polymer, whereas the addition of TBA resulted in the conversion of monomers in polymer. The DC of the adhesives was as higher as the increase in the TBA content. The group with 2 mol % of TBA presented improved DC and reactivity (RP ) than the other groups and the control one. Hence, the TBA has performed as a coinitiator of the CQ for the radical polymerization of methacrylate resin adhesives and it has improved the DC and the reactivity of the materials. Thus, it is a potential coinitiator for the photopolymerization of dental materials.
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Affiliation(s)
- Eliseu A Münchow
- Department of Operative Dentistry, School of Dentistry, Federal University of Pelotas, Rio Grande do Sul, Brazil
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15
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Cekic-Nagas I, Egilmez F, Ergun G, Kaya BM. Light transmittance of zirconia as a function of thickness and microhardness of resin cements under different thicknesses of zirconia. Med Oral Patol Oral Cir Bucal 2013; 18:e212-8. [PMID: 23385497 PMCID: PMC3613872 DOI: 10.4317/medoral.18181] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 08/05/2012] [Indexed: 02/04/2023] Open
Abstract
OBJECTIVE The objective of this study was to compare microhardness of resin cements under different thicknesses of zirconia and the light transmittance of zirconia as a function of thickness. STUDY DESIGN A total of 126 disc-shaped specimens (2 mm in height and 5 mm in diameter) were prepared from dual-cured resin cements (RelyX Unicem, Panavia F and Clearfil SA cement). Photoactivation was performed by using quartz tungsten halogen and light emitting diode light curing units under different thicknesses of zirconia. Then the specimens (n=7/per group) were stored in dry conditions in total dark at 37°C for 24 h. The Vicker's hardness test was performed on the resin cement layer with a microhardness tester. Statistical significance was determined using multifactorial analysis of variance (ANOVA) (alpha=.05). Light transmittance of different thicknesses of zirconia (0.3, 0.5 and 0.8 mm) was measured using a hand-held radiometer (Demetron, Kerr). Data were analyzed using one-way ANOVA test (alpha=.05). RESULTS ANOVA revealed that resin cement and light curing unit had significant effects on microhardness (p < 0.001). Additionally, greater zirconia thickness resulted in lower transmittance. There was no correlation between the amount of light transmitted and microhardness of dual-cured resin cements (r = 0.073, p = 0.295). CONCLUSION Although different zirconia thicknesses might result in insufficient light transmission, dual-cured resin cements under zirconia restorations could have adequate microhardness.
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Affiliation(s)
- Isil Cekic-Nagas
- Gazi University, Faculty of Dentistry, Department of Prosthodontics, Ankara, Turkey.
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16
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Reginato CF, Oliveira AS, Kaizer MR, Jardim PS, Moraes RR. Polymerization efficiency through translucent and opaque fiber posts and bonding to root dentin. J Prosthodont Res 2012; 57:20-3. [PMID: 23116926 DOI: 10.1016/j.jpor.2012.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2012] [Revised: 04/16/2012] [Accepted: 05/23/2012] [Indexed: 10/27/2022]
Abstract
PURPOSE To investigate the polymerization efficiency through translucent and opaque glass fiber posts and the bond strength of a self-adhesive resin to root dentin. METHODS Translucent and opaque silanated conical posts, identical in length, diameter and shape (n=8), were cemented to incisor bovine roots using RelyX Unicem Clicker. Photoactivation was performed only through the posts. The roots were transversally sectioned (cervical, middle and apical thirds) and the push-out test was carried out. Data were analyzed using two-way ANOVA and Fisher's LSD method (5%). Failure modes were classified under magnification. An elastomer mold of a bovine incisor root was filled with flowable composite and the posts inserted into the mold. After photoactivation through the post and removal of unpolymerized material, the polymerization efficiency was estimated by percentage of mass gain (n=5). Data were analyzed using t-test (5%). RESULTS The bond strength of the translucent post was higher than the opaque post for all root thirds. For both posts the bond strength at the cervical third was higher than at the middle and apical thirds. A predominance of adhesive failures was detected for all conditions. Mixed failures were more frequently observed for the opaque post. Almost all the composite polymerized and bonded to the extension of the translucent post, whereas polymerization of the composite was restricted to the cervical area of the opaque post. CONCLUSIONS The use of translucent post may positively influence the polymerization efficiency and bond strength of resin cement to intraradicular dentin.
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Affiliation(s)
- Cássia F Reginato
- School of Dentistry, Federal University of Pelotas, Pelotas-RS, Brazil
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17
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Vignolo V, Fuentes MV, Garrido MA, Rodríguez J, Ceballos L. Microhardness of different resin cement shades inside the root canal. Med Oral Patol Oral Cir Bucal 2012; 17:e859-64. [PMID: 22322514 PMCID: PMC3482534 DOI: 10.4317/medoral.17802] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 11/13/2011] [Indexed: 11/07/2022] Open
Abstract
Objectives: To compare microhardness along the root canal post space of two resin cements in different shades and a dual-cure resin core material.
Study Design: Root canals of 21 bovine incisors were prepared for post space. Translucent posts (X•Post, Dentsply DeTrey) were luted using one the following resin luting agent: Calibra (Dentsply DeTrey) in Translucent, Medium and Opaque shades, RelyX Unicem (3M ESPE) in Translucent, A2 and A3 shades and the dual-cure resin core material Core•X flow. All materials were applied according to manufacturers’ instructions and were all photopolymerized (Bluephase LED unit, Ivoclar Vivadent, 40s). After 24 hours, roots were transversally cut into 9 slices 1 mm thick from the coronal to apical extremes, three corresponding to each root third. Then, VHNs were recorded (100 gf, 30 s) on the resin luting materials along the adhesive interface in all sections. Data were analyzed by two-way ANOVA and SNK tests (α=0.05).
Results: A significant influence on microhardness of resin luting material in their respective shades (p<0.001), root third (p<0.001) and interactions between them was detected (p<0.001). RelyX Unicem cement showed the highest microhardness values and Calibra the lowest, regardless of the shade selected. All resin luting materials tested exhibited a significantly higher microhardness in the cervical third.
Conclusions: Microhardness of resin luting agents tested inside the canal is dependent on material brand and resin cement shade seems to be a less relevant factor. Microhardness decreased along the root canal, regardless of the shade selected.
Key words:Cement shade, degree of conversion, dual-cured resin cements, fiber posts, microhardness, root thirds.
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Affiliation(s)
- Valeria Vignolo
- Department of Stomatology, Rey Juan Carlos University, Avda. de Atenas s/n, 28922 Alcorcón, Madrid, Spain
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18
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Puppin-Rontani RM, Dinelli RG, de Paula AB, Fucio SBP, Ambrosano GMB, Pascon FM. In-depth polymerization of a self-adhesive dual-cured resin cement. Oper Dent 2011; 37:188-94. [PMID: 22166106 DOI: 10.2341/10-288-l] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aim of this study was to assess Knoop hardness at different depths of a dual-cured self-adhesive resin cement through different thicknesses of Empress Esthetic® ceramic.Flattened bovine dentin was embedded in resin. The cement was inserted into a rubber mold (0.8 x 5 mm) that was placed between two polyvinyl chloride plastic films and placed over the flat dentin and light cured by Elipar Trilight-QTH (800 mW/cm2) or Ultra-Lumelight-emitting diode (LED 5; 1585 mW/cm2) over ceramic disks 1.4 or 2 mm thick. The specimens(n=6) were stored for 24 hours before Knoop hardness (KHN) was measured. The data were submitted to analysis of variance in a factorial split-plot design and Tukey's test (a=0.05).There was significant interaction among the study factors. In the groups cured by the QTHunit, an increase in ceramic thickness resulted in reduced cement hardness values at all depths, with the highest values always being found in the center (1.4 mm, 58.1; 2 mm, 50.1)and the lowest values at the bottom (1.4 mm,23.8; 2 mm, 20.2). When using the LED unit, the hardness values diminished with increased ceramic thickness only on the top (1.4 mm,51.5; 2 mm, 42.3). In the group with the 1.4-mm-thick disk, the LED curing unit resulted in similar values on the top (51.5) and center(51.9) and lower values on the bottom (24.2).However, when the cement was light cured through the 2-mm disk, the highest hardness value was obtained in the center (51.8), followed by the top (42.3) and bottom (19.9),results similar to those obtained with the QTH curing unit (center > top > bottom). The hardness values of the studied cement at different depths were dependent on the ceramic thickness but not on the light curing units used.
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19
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Cekic-Nagas I, Ergun G. Effect of different light curing methods on mechanical and physical properties of resin-cements polymerized through ceramic discs. J Appl Oral Sci 2011; 19:403-12. [PMID: 21710093 PMCID: PMC4223794 DOI: 10.1590/s1678-77572011005000017] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Accepted: 10/26/2010] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE The aim of this study was to compare the polimerization ability of three different light-curing units (quartz tungsten halogen, light-emitting diodes and plasma arc) and their exposure modes (high-intensity and soft-start) by determination of microhardness, water sorption and solubility, and diametral tensile strength of 5 dual-curing resin cements. MATERIAL AND METHODS A total of 720 disc-shaped samples (1 mm height and 5 mm diameter) were prepared from different dual-curing resin cements (Duolink, Nexus, Bifix-QM, Panavia F and RelyX Unicem). Photoactivation was performed by using quartz tungsten halogen (high-power and soft-up modes), light-emitting diode (standard and exponential modes) and plasma arc (normal and ramp-curing modes) curing units through ceramic discs. Then the samples (n=8/per group) were stored dry in the dark at 37°C for 24 h. The Vickers hardness test was performed on the resin cement layer with a microhardness tester (Shimadzu HMV). For sorption and solubility tests; the samples were stored in a desiccator at 37°C and weighed to a constant mass. The samples were weighed both before and after being immersed in deionized water for different periods of time (24 h and 7 days) and being desiccated. The diametral tensile strength of the samples was tested in a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by nonparametric Kruskal Wallis and Mann-Whitney U tests at 5% significance level. RESULTS Resin cement and light-curing unit had significant effects (p<0.05) on microhardness, diametral tensile strength, water solubility and sorption. However, no significant differences (p>0.05) were obtained with different modes of LCUs. CONCLUSION The study indicates that polymerization of resin cements with different light-curing units may result in various polymer structures, and consequently different mechanical and physical properties.
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Affiliation(s)
- Isil Cekic-Nagas
- Department of Prosthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
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Turp V, Sen D, Poyrazoglu E, Tuncelli B, Goller G. Influence of zirconia base and shade difference on polymerization efficiency of dual-cure resin cement. J Prosthodont 2011; 20:361-5. [PMID: 21627708 DOI: 10.1111/j.1532-849x.2011.00721.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
PURPOSE The aim of this study was to investigate the polymerization efficiency of dual-cured resin cement beneath different shades of zirconia-based feldsphathic ceramic restorations. MATERIALS AND METHODS Five translucent zirconia (Zirkonzahn) discs (4.0-mm diameter, 1.2-mm height) were prepared. Feldsphathic ceramic (1.2 mm) (Noritake Cerabien Zr) in 5 shades (1M2, 2M2, 3M2, 4M2, 5M2) was applied on the zirconia discs. Twelve dual-cure resin cement specimens were prepared for each shade, using Panavia F 2.0 (Kuraray) in Teflon molds (4.0-mm diameter, 6.0-mm height), following the manufacturer's instructions. Light activation was performed through the zirconia-based ceramic discs for 20 seconds, using a quartz tungsten halogen curing device (Hilux 200) with irradiance of 600 mW/cm(2) . Immediately following light curing, specimens were stored for 24 hours in dry, light-proof containers. Vickers hardness measurements were conducted using a microhardness tester with a 50-g load applied for 15 seconds. The indentations were made in the cross sectional area at four depths, and the mean values were recorded as Vickers hardness number (VHN). Results were statistically analyzed with one-way ANOVA and Tukey HSD test (p < 0.05). RESULTS A statistically significant decrease in VHN of the resin cement was noted with increasing depth and darkness of the shade (p < 0.05). CONCLUSION Curing efficiency of dual-cure resin cement is mainly influenced by the lightness of the shades selected.
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Affiliation(s)
- Volkan Turp
- Department of Prosthodontics, Istanbul University Faculty of Dentistry, Istanbul, Turkey.
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21
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Reges RV, Costa AR, Correr AB, Piva E, Puppin-Rontani RM, Sinhoreti MAC, Correr-Sobrinho L. Effect of light-curing units, post-cured time and shade of resin cement on knoop hardness. Braz Dent J 2009; 20:410-3. [PMID: 20126910 DOI: 10.1590/s0103-64402009000500009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Accepted: 11/19/2009] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to evaluate the Knoop hardness after 15 min and 24 h of different shades of a dual-cured resin-based cement after indirect photoactivation (ceramic restoration) with 2 light-curing units (LCUs). The resin cement Variolink II (Ivoclar Vivadent) shade XL, A2, A3 and opaque were mixed with the catalyst paste and inserted into a black Teflon mold (5 mm diameter x 1 mm high). A transparent strip was placed over the mold and a ceramic disc (Duceram Plus, shade A3) was positioned over the resin cement. Light-activation was performed through the ceramic for 40 s using quartz-tungsten-halogen (QTH) (XL 2500; 3M ESPE) or light-emitting diode (LED) (Ultrablue Is, DMC) LCUs with power density of 615 and 610 mW/cm2, respectively. The Koop hardness was measured using a microhardness tester HMV 2 (Shimadzu) after 15 min or 24 h. Four indentations were made in each specimen. Data were subjected to ANOVA and Tukey's test (a=0.05). The QTH LCU provided significantly higher (p<0.05) KHN values than the LED LCU. When the post-cure times were compared for the same shade, QTH and LED at 24 h provided significantly higher (p<0.05) KHN values than at 15 min. It may be concluded that the Knoop hardness was generally dependent on the LCU and post-cure time. The opaque shade of the resin cement showed lower Knoop hardness than the other shades for both LCUs and post-cure times.
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Moraes RR, Sinhoreti MAC, Correr-Sobrinho L, Ogliari FA, Piva E, Petzhold CL. Preparation and evaluation of dental resin luting agents with increasing content of bisphenol-A ethoxylated dimethacrylate. J Biomater Appl 2008; 24:453-73. [PMID: 19033325 DOI: 10.1177/0885328208098594] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Resin luting agents in which bisphenol-A glycidyl dimethacrylate (Bis-GMA) and/or triethylene glycol dimethacrylate (TEGDMA) are replaced with increasing amounts of bisphenol-A ethoxylated dimethacrylate are prepared. Degree of conversion (DC), diametral tensile strength (DTS), Young's modulus (YM), Knoop hardness (KHN), film thickness (FT), water sorption (W(sp) ), and solubility are evaluated. Regression analyses investigate the substitution of each monomer. The most appreciable differences are detected when TEGDMA is replaced: decreased DC, DTS, and W(sp), and increased YM, KHN, and FT. For substitution of Bis-GMA, the only significant differences are reduced W(sp) and increased YM. An ideal formulation of resin cement would make use of the three monomers.
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Affiliation(s)
- Rafael R Moraes
- Department of Restorative Dentistry, Dental Materials Division Piracicaba Dental School, P.O. BOX 52, University of Campinas-UNICAMP Av. Limeira 901-13414-903-Piracicaba, SP-Brazil
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