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Kincses D, Jordáki D, Szebeni D, Kunsági-Máté S, Szalma J, Lempel E. Effect of Ceramic and Dentin Thicknesses and Type of Resin-Based Luting Agents on Intrapulpal Temperature Changes during Luting of Ceramic Inlays. Int J Mol Sci 2023; 24:ijms24065466. [PMID: 36982546 PMCID: PMC10057599 DOI: 10.3390/ijms24065466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/06/2023] [Accepted: 03/10/2023] [Indexed: 03/16/2023] Open
Abstract
The adhesive cementation of ceramic inlays may increase pulpal temperature (PT) and induce pulpal damage due to heat generated by the curing unit and the exothermic reaction of the luting agent (LA). The aim was to measure the PT rise during ceramic inlay cementation by testing different combinations of dentin and ceramic thicknesses and LAs. The PT changes were detected using a thermocouple sensor positioned in the pulp chamber of a mandibular molar. Gradual occlusal reduction obtained dentin thicknesses of 2.5, 2.0, 1.5, and 1.0 mm. Light-cured (LC) and dual-cured (DC) adhesive cements and preheated restorative resin-based composite (RBC) were applied to luting of 2.0, 2.5, 3.0, and 3.5 mm lithium disilicate ceramic blocks. Differential scanning calorimetry was used to compare the thermal conductivity of dentin and ceramic slices. Although ceramic reduced heat delivered by the curing unit, the exothermic reaction of the LAs significantly increased it in each investigated combination (5.4–7.9 °C). Temperature changes were predominantly influenced by dentin thickness followed by LA and ceramic thickness. Thermal conductivity of dentin was 24% lower than that of ceramic, and its thermal capacity was 86% higher. Regardless of the ceramic thickness, adhesive inlay cementation can significantly increase the PT, especially when the remaining dentin thickness is <2 mm.
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Affiliation(s)
- Dóra Kincses
- Department of Restorative Dentistry and Periodontology, Faculty of Dentistry, University of Pécs Medical School, PTüzér Street 1, 7623 Pécs, Hungary
| | - Dóra Jordáki
- Department of Restorative Dentistry and Periodontology, Faculty of Dentistry, University of Pécs Medical School, PTüzér Street 1, 7623 Pécs, Hungary
| | - Donát Szebeni
- Department of Restorative Dentistry and Periodontology, Faculty of Dentistry, University of Pécs Medical School, PTüzér Street 1, 7623 Pécs, Hungary
| | - Sándor Kunsági-Máté
- Department of Organic and Medicinal Chemistry, Faculty of Pharmacy, University of Pécs, Honvéd Street 1, 7624 Pécs, Hungary
- János Szentágothai Research Center, Ifjúság Street 20, 7624 Pécs, Hungary
| | - József Szalma
- Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, University of Pécs Medical School, Tüzér Street 1, 7623 Pécs, Hungary
| | - Edina Lempel
- Department of Restorative Dentistry and Periodontology, Faculty of Dentistry, University of Pécs Medical School, PTüzér Street 1, 7623 Pécs, Hungary
- Correspondence: ; Tel.: +36-(72)-536402
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Babaier R, Haider J, Silikas N, Watts DC. Effect of CAD/CAM aesthetic material thickness and translucency on the polymerisation of light- and dual-cured resin cements. Dent Mater 2022; 38:2073-2083. [DOI: 10.1016/j.dental.2022.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/11/2022] [Accepted: 11/11/2022] [Indexed: 11/27/2022]
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Intrapulpal temperature changes during the cementation of ceramic veneers. Sci Rep 2022; 12:12919. [PMID: 35902776 PMCID: PMC9334278 DOI: 10.1038/s41598-022-17285-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 07/22/2022] [Indexed: 12/03/2022] Open
Abstract
Adhesive cementation of ceramic veneers may increase pulpal temperature (PT) due to the combined effect of heat generated by the curing unit and the exothermic reaction of the luting agent (LA). PT increase may induce pulpal damage. The aim was to determine the PT rise during the luting of ceramic veneers (CV) of different thicknesses with light- or dual-curing (LC, DC) adhesive cements as well as pre-heated restorative resin-based composites (PH-RBC). For this a thermocouple sensor was positioned in the pulp chamber of a prepared maxillary central incisor. LC, DC adhesive cements and PH-RBCs heated to 55 °C were used for the luting of CVs of 0.3, 0.5, 0.7, and 1.0 mm thicknesses. The exothermic reaction of LAs added significantly to the thermal effect of the curing unit. PT change ranged between 8.12 and 14.4 °C with the investigated combinations of LAs and ceramic thicknesses (p ≤ 0.01). The increase was inversely proportional to the increasing CV thicknesses. The highest rise (p ≤ 0.01) was seen with the polymerization of PH-RBCs. Temperature changes were predominantly influenced by the composition of the LA, which was followed by CV thickness.
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Yang B, Huang Q, Holmes B, Guo J, Li Y, Heo Y, Chew HP, Wang Y, Fok A. Influence of curing modes on the degree of conversion and mechanical parameters of dual-cured luting agents. J Prosthodont Res 2019; 64:137-144. [PMID: 31862437 DOI: 10.1016/j.jpor.2019.06.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 06/02/2019] [Accepted: 06/10/2019] [Indexed: 11/28/2022]
Abstract
PURPOSE To investigate the effects of different curing modes, including tack cure, on the degree of conversion (DC) and mechanical parameters of dual-cured luting agents for all-ceramic restorations. METHODS Immediate light curing, intermittent light curing (2-s tack cure and a 1-min interval before the main cure), delayed light cuing (2-min delay) and chemical or no light curing were used to cure two dual-cured luting agents, RelyX Unicem and PermaCem 2.0, through a 1.5-mm thick lithium disilicate ceramic slide. DC (n=3), micro-hardness (n=5), shrinkage strain (n=4) and shrinkage stress (n=3) were measured under the aforementioned curing modes. The data were analyzed using two-way ANOVA and post-hoc Tukey HSD test, with the level of significance set at α=0.05. RESULTS For both luting agents, all the light-curing modes produced similar final DC, but using chemical cure only could significantly reduce the DC. The mechanical parameters followed a similar pattern. There were positive but nonlinear correlations between DC and the other mechanical parameters, with the increase in these parameters with DC being slower initially. CONCLUSIONS Provided adequate light curing is applied to a dual-cured luting agent, delaying the light curing or using a tack cure first to facilitate seating of a restoration may not have a significant impact on the luting agent's final degree of conversion. However, using chemical cure only may result in inadequate cure of the luting agent and is recommended only for highly opaque restorations.
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Affiliation(s)
- Bo Yang
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, 56 Lingyuan West Road, Guangzhou 510055, China.
| | - Qin Huang
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, 56 Lingyuan West Road, Guangzhou 510055, China.
| | - Brian Holmes
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis 55455, USA.
| | - Jiawen Guo
- State Key Laboratory of Military Stomatology, Department of Prosthodontics, School of Stomatology, Fourth Military Medical University, Xi'an 710032, China.
| | - Yuping Li
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis 55455, USA.
| | - Young Heo
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis 55455, USA.
| | - Hooi Pin Chew
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis 55455, USA.
| | - Yan Wang
- Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Stomatology, 56 Lingyuan West Road, Guangzhou 510055, China.
| | - Alex Fok
- Minnesota Dental Research Center for Biomaterials and Biomechanics, School of Dentistry, University of Minnesota, Minneapolis 55455, USA.
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Mendonça LMD, Ramalho IS, Lima LASN, Pires LA, Pegoraro TA, Pegoraro LF. Influence of the composition and shades of ceramics on light transmission and degree of conversion of dual-cured resin cements. J Appl Oral Sci 2019; 27:e20180351. [PMID: 31365707 PMCID: PMC6690711 DOI: 10.1590/1678-7757-2018-0351] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 02/01/2019] [Indexed: 12/22/2022] Open
Abstract
Objective Since the transmittance of ceramics can influence the degree of conversion (DC) of resin cements, ceramics composition and shade should be considered in the selection of resin cement. This in vitro study aimed to evaluate the effect of the transmittance of different composition, opacities and shades of ceramics on the degree of conversion of two dual-cured resin cements. Methodology Sixty discs were prepared from low translucency (LT) and medium opacity (MO) lithium disilicate ceramic, and zirconia ceramic (Z). Each group was subdivided into 5 subgroups (n=4) in shades A2, A3.5, B2, C2 and D3. The transmittance measurement was performed in a spectrophotometer. The Variolink II and Rely X U200 resin cements were photoactivated by LED (1400 mW/cm2) for 40 s through the ceramic discs and without the discs (control group). The DC was measured with infrared FTIR spectroscopy, immediately after light activation. Data were analyzed with Kruskall-Wallis and one-way ANOVA, following post-hoc comparisons by Tukey test and Pearson’s correlation test (P<0.05). Results LT ceramic exhibited higher transmittance values compared to MO and Z ceramics. LTA2 and LTB2 showed statistically higher transmittance values compared to MOA2, MOA3.5 and ZA3.5. For Variolink II, the ceramic interposition did not influence the DC, since there were no statistical differences between groups with ceramic interposition and the control group. For Rely X U200 cement, the interposition of some ceramics types/shades (LTA3.5, MOA2, MOA3.5 and ZA3.5) significantly decreased the DC values compared to control group. A positive correlation was found between the ceramic transmittance and DC values of both tested cements. Conclusions. The transmittance and DC values of the cements were influenced by composition and shades of the ceramics. The higher the transmittance of ceramics, the higher the DC values for both cements.
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Affiliation(s)
| | - Ilana Santos Ramalho
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departmento de Prótese e Periodontia, Bauru, São Paulo, Brasil
| | | | - Laís Alcântara Pires
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departmento de Prótese e Periodontia, Bauru, São Paulo, Brasil
| | - Thiago Amadei Pegoraro
- Universidade do Sagrado Coração, Faculdade de Odontologia, Departamento de Prótese, Bauru, São Paulo, Brasil
| | - Luiz Fernando Pegoraro
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departmento de Prótese e Periodontia, Bauru, São Paulo, Brasil
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Lanza MDS, Andreeta MRB, Pegoraro TA, Pegoraro LF, Carvalho RMD. Influence of curing protocol and ceramic composition on the degree of conversion of resin cement. J Appl Oral Sci 2018; 25:700-707. [PMID: 29211292 PMCID: PMC5701541 DOI: 10.1590/1678-7757-2016-0270] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 03/20/2017] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE Due to increasing of aesthetic demand, ceramic crowns are widely used in different situations. However, to obtain long-term prognosis of restorations, a good conversion of resin cement is necessary. To evaluate the degree of conversion (DC) of one light-cure and two dual-cure resin cements under a simulated clinical cementation of ceramic crowns. MATERIAL AND METHODS Prepared teeth were randomly split according to the ceramic's material, resin cement and curing protocol. The crowns were cemented as per manufacturer's directions and photoactivated either from occlusal suface only for 60 s; or from the buccal, occlusal and lingual surfaces, with an exposure time of 20 s on each aspect. After cementation, the specimens were stored in deionized water at 37°C for 7 days. Specimens were transversally sectioned from occlusal to cervical surfaces and the DC was determined along the cement line with three measurements taken and averaged from the buccal, lingual and approximal aspects using micro-Raman spectroscopy (Alpha 300R/WITec®). Data were analyzed by 3-way ANOVA and Tukey test at =5%. RESULTS Statistical analysis showed significant differences among cements, curing protocols and ceramic type (p<0.001). The curing protocol 3x20 resulted in higher DC for all tested conditions; lower DC was observed for Zr ceramic crowns; Duolink resin cement culminated in higher DC regardless ceramic composition and curing protocol. CONCLUSION The DC of resin cement layers was dependent on the curing protocol and type of ceramic.
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Affiliation(s)
| | - Marcello Rubens Barsi Andreeta
- Universidade Federal de São Carlos, Departamento de Engenharia de Materiais, Laboratório de Materiais Vítreos, São Carlos, SP, Brasil
| | - Thiago Amadei Pegoraro
- Universidade do Sagrado Coração, Departamento de Prótese e Implantodontia, Bauru, SP, Brasil
| | - Luiz Fernando Pegoraro
- Universidade de São Paulo, Faculdade de Odontologia de Bauru, Departamento de Prótese e Periodontia, Bauru, SP, Brasil
| | - Ricardo Marins De Carvalho
- University of British Columbia, Faculty of Dentistry, Department of Oral Biological and Medical Sciences, Division of Biomaterials, Vancouver, Canada
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Novais VR, Raposo LHA, Miranda RRD, Lopes CDCA, Simamoto PC, Soares CJ. Degree of conversion and bond strength of resin-cements to feldspathic ceramic using different curing modes. J Appl Oral Sci 2017; 25:61-68. [PMID: 28198977 PMCID: PMC5289401 DOI: 10.1590/1678-77572016-0221] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 09/26/2016] [Indexed: 11/26/2022] Open
Abstract
Resin cements have led to great advances in dental ceramic restoration techniques because of their ability to bond to both dental structures and restorative materials.
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Affiliation(s)
- Veridiana Resende Novais
- Universidade Federal de Uberlândia, Faculdade de Odontologia, Departamento de Dentística e Materiais Odontológicos, Uberlândia, MG, Brasil
| | - Luís Henrique Araújo Raposo
- Universidade Federal de Uberlândia, Faculdade de Odontologia, Departamento de Oclusão, Prótese Fixa e Materiais Odontológicos, Uberlândia, MG, Brasil
| | | | | | - Paulo Cézar Simamoto
- Universidade Federal de Uberlândia, Faculdade de Odontologia, Departamento de Oclusão, Prótese Fixa e Materiais Odontológicos, Uberlândia, MG, Brasil
| | - Carlos José Soares
- Universidade Federal de Uberlândia, Faculdade de Odontologia, Departamento de Dentística e Materiais Odontológicos, Uberlândia, MG, Brasil
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Lopes CDCA, Rodrigues RB, Silva ALFE, Simamoto Júnior PC, Soares CJ, Novais VR. Degree of Conversion and Mechanical Properties of Resin Cements Cured Through Different All-Ceramic Systems. Braz Dent J 2015; 26:484-9. [DOI: 10.1590/0103-6440201300180] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 07/07/2015] [Indexed: 12/21/2022] Open
Abstract
Abstract: The aim of this study was to verify the degree of conversion (DC), Vickers microhardness (VH) and elastic modulus (E) of resin cements cured through different ceramic systems. One 1.5-mm-thick disc of each ceramic system (feldspathic, lithium dissilicate and zircônia veneered with feldspathic) was used. Three dual-cured (Allcem, Variolink II and RelyX U200) and one chemically-cured (Multilink) resin cements were activated through ceramic discs. For dual-cured resin cements was used a conventional halogen light-curing unit (Optilux 501 at 650 mW/cm2 for 120 s). Samples cured without the ceramic disc were used as control. The samples were stored at 37 °C for 24 h. ATR/FTIR spectrometry was used to evaluate the extent of polymerization in the samples (n=5). Micromechanical properties - VH and E - of the resin cements (n=5) were measured with a dynamic indentation test. Data were statistically analyzed with two-way ANOVA, Tukey's test and Pearson's correlation (α=0.05). DC was affected only by the type of resin cement (p=0.001). For VH, significant interaction was detected between resin cement and ceramic (p=0.045). The dual-cured resin cements showed no significant differences in mean values for E and significantly higher values than the chemically-cured resin cement. The degree of conversion and the mechanical properties of the evaluated resin cements depend on their activation mode and the type of ceramics used in 1.5 mm thickness. The dual-cured resin cements performed better than the chemically-cured resin cement in all studied properties.
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Chang HS, Hong SO. Effects of layering technique on the shade of resin overlays and the microhardness of dual cure resin cement. Braz Oral Res 2014; 28:S1806-83242014000100233. [PMID: 24918368 DOI: 10.1590/1807-3107bor-2014.vol28.0016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 04/22/2014] [Indexed: 11/21/2022] Open
Abstract
The purpose of this study was to assess the color of layered resin overlays and to test the early microhardness of dual cure resin cement (DCRC) light cured through the layered resin overlays. Resin overlays of 1.5 mm thickness were fabricated with the A3 shade of Z350 (Group 1L), the A3B and A3E shades of Supreme XT (Group 2L), and the A3, E3, and T1 shades of Sinfony (Group 3L) using one, two, and three layers, respectively (n=7). Each layer of the resin overlays was set in equal thickness. The color of the resin overlays was measured with a colorimeter and compared with an A3 shade resin denture tooth. DCRC was light cured through the resin overlays, and the early microhardness of the DCRC was measured. The ΔE value between the denture tooth and the resin overlays and the Vickers hardness number (VHN) of the DCRC were analyzed with one-way ANOVA and Tukey's HSD test. The color differences were 8.9±0.5, 5.3±1.0, and 7.3±0.5 and the VHNs were 19.4±1.1, 21.1±0.9, and 29.3±0.6 for Groups 1L, 2L, and 3L, respectively. Therefore, to match the designated tooth color of resin inlays and to increase the early microhardness of DCRC, layered resin inlays are more appropriate than single-dentin-layer resin inlays. However, the translucent layer should be used cautiously because the color difference of resin inlays with a translucent layer was affected more than those without a translucent layer.
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Affiliation(s)
- Hoon-Sang Chang
- Department of Conservative Dentistry, School of Dentistry, Chonnam National University, Gwangju, Korea
| | - Sung-Ok Hong
- Department of Conservative Dentistry, School of Dentistry, Wonkwang University, Iksan, Korea
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Mainardi MDCAJ, Giorgi MCC, Lima DANL, Marchi GM, Ambrosano GM, Paulillo LAMS, Aguiar FHB. Effect of energy density and delay time on the degree of conversion and Knoop microhardness of a dual resin cement. ACTA ACUST UNITED AC 2014; 6:53-8. [PMID: 24510456 DOI: 10.1111/jicd.12075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 06/09/2013] [Indexed: 11/29/2022]
Abstract
AIM In the present study, we evaluated the influence of the photo-curing delay time and energy density on the degree of conversion and the Knoop microhardness of a resin cement. METHODS Seventy-eight samples were assigned to 13 groups (n = 6), one of which received no light curing (control). The samples were made of a dual-cured resin cement (RelyX ARC) with the aid of a Teflon matrix, submitted to one of the following energy densities (J/cm²): 7, 14, 20, and 28. Delay times were immediate (0), 1 min, or 2 min. After 24 h, the degree of conversion and microhardness were measured at three segments: cervical, medium, and apical. Data were submitted to three-way anova and Tukey's and Dunnett's tests, the latest of which was used to compare the control to the experimental groups. RESULTS No interaction was observed between delay time and energy density regarding the degree of conversion. The cervical segment showed the highest values, while the apical showed the lowest. Microhardness values concerning the cervical segment in all groups were statistically different from that obtained for the control. CONCLUSION A high-irradiance light-curing unit allows for a reduced irradiation exposure time with a short delay time, aimed at tooth restorations using a dual-cured resin cement.
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Chang HS, Kim JW. Early hardness and shear bond strength of dual-cure resin cement light cured through resin overlays with different dentin-layer thicknesses. Oper Dent 2013; 39:398-406. [PMID: 24191869 DOI: 10.2341/13-122-l] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The purpose of this study was to investigate whether dentin-layer thickness of resin overlays could affect the early hardness and shear bond strength of dual-cure resin cement (DCRC, RelyX ARC) after light curing with light curing units (LCUs) of various power densities: Optilux 360 (360), Elipar Freelight 2 (FL2), and Elipar S10 (S10). Resin overlays were fabricated using an indirect composite resin (Sinfony) with a dentin layer, an enamel layer, and a translucent layer of 0.5 mm thickness each (0.5-0.5-0.5) or of 0.2 mm, 0.5 mm, and 0.8 mm thickness (0.2-0.5-0.8), respectively. The DCRC was light cured for 40 seconds through the overlays, and surface hardness and shear bond strength to bovine dentin were tested 10 minutes after the start of light curing. Surface hardness was higher when the DCRC was light cured through the 0.2-0.5-0.8 combination than when the DCRC was light cured through the 0.5-0.5-0.5 combination with all LCUs. The ratio of upper surface hardness of DCRC light cured through resin overlays relative to the upper surface hardness of DCRC light cured directly was more than 90% only when the DCRC was light cured with S10 through the 0.2-0.5-0.8 combination. The shear bond strength value was higher when the DCRC was light cured with S10 through the 0.2-0.5-0.8 combination than when light cured with S10 through the 0.5-0.5-0.5 combination. This study indicates that reducing the dentin-layer thickness while increasing the translucent-layer thickness of resin inlays can increase the photopolymerization of DCRC, thereby increasing the early bond strength of resin inlays to dentin.
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Souza EJ, Borges BCD, Oliveira DCRS, Brandt WC, Hirata R, Silva EJNL, Sinhoreti MAC. Influence of the curing mode on the degree of conversion of a dual-cured self-adhesive resin luting cement beneath ceramic. Acta Odontol Scand 2013; 71:444-8. [PMID: 22630602 DOI: 10.3109/00016357.2012.690571] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE To evaluate the effect of the delayed photoactivation and ceramic barrier on the degree of conversion (DC) of self-adhesive resin cement. MATERIALS AND METHODS Circular specimens (5 mm in diameter × 1 mm in thickness) of the RelyX U-100 resin cement were made using the following curing protocols (n = 10): (G1) 40 s beneath a IPS Empress II ceramic; (G2) 40 s of direct photocuring; (G3) 80 s beneath the ceramic; (G4) 80 s of direct photocuring; (G5) self-curing; (G6) 5 min in the absence of light (self-curing) followed by transceramic photocuring for 40 s; (G7) 5 min in the absence of light (self-curing) followed by transceramic photocuring for 80 s. All the specimens were photoactivated by LED (800 mW/cm(2)). After 24 h of dry storage, the DC was measured by FTIR, on the top surface of the specimens. Data were submitted to one-way ANOVA and Tukey test (p ≤ 0.05). RESULTS Direct photocuring with no ceramic interposition, regardless of the curing time (40 s and 80 s) promoted the highest conversion mean (56.79 ± 1.19 and 59.98 ± 2.93, respectively) and the 5 min delay time for the transceramic photocuring presented a similar mean compared to the immediate transceramic photocuring. The DC was influenced by the ceramic barrier, decreasing the conversion values (49.72 ± 1.91 for 40 s and 52.36 ± 2.50 for 80 s), with no statistical difference from the groups with the previous 5 min of photoactivation delay. The self-cure only showed the worst DC values. CONCLUSION Direct photocuring provided a higher degree of conversion for the self-adhesive resin cement. The delayed light activation did not influence the degree of conversion for the resin cement tested.
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Affiliation(s)
- Eduardo José Souza
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, São Paulo, Brazil.
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13
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Hwang IN, Hong SO, Lee BN, Hwang YC, Oh WM, Chang HS. Effect of a multi-layer infection control barrier on the micro-hardness of a composite resin. J Appl Oral Sci 2013; 20:576-80. [PMID: 23138746 PMCID: PMC3881790 DOI: 10.1590/s1678-77572012000500014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 09/13/2012] [Indexed: 11/22/2022] Open
Abstract
Objective The aim of this study was to evaluate the effect of multiple layers of an
infection control barrier on the micro-hardness of a composite resin. Material and Methods One, two, four, and eight layers of an infection control barrier were used to
cover the light guides of a high-power light emitting diode (LED) light curing
unit (LCU) and a low-power halogen LCU. The composite specimens were
photopolymerized with the LCUs and the barriers, and the micro-hardness of the
upper and lower surfaces was measured (n=10). The hardness ratio was calculated by
dividing the bottom surface hardness of the experimental groups by the irradiated
surface hardness of the control groups. The data was analyzed by two-way ANOVA and
Tukey's HSD test. Results The micro-hardness of the composite specimens photopolymerized with the LED LCU
decreased significantly in the four- and eight-layer groups of the upper surface
and in the two-, four-, and eight-layer groups of the lower surface. The hardness
ratio of the composite specimens was <80% in the eight-layer group. The
micro-hardness of the composite specimens photopolymerized with the halogen LCU
decreased significantly in the eight-layer group of the upper surface and in the
two-, four-, and eight-layer groups of the lower surface. However, the hardness
ratios of all the composite specimens photopolymerized with barriers were <80%.
Conclusions The two-layer infection control barrier could be used on high-power LCUs without
decreasing the surface hardness of the composite resin. However, when using an
infection control barrier on the low-power LCUs, attention should be paid so as
not to sacrifice the polymerization efficiency.
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Affiliation(s)
- In-Nam Hwang
- Department of Conservative Dentistry and Dental Science Research Institute, School of Dentistry, Chonnam National University, Gwangju, Korea
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Prieto LT, Souza EJ, Araújo CTP, Lima AF, Dias CTDS, Paulillo LAMS. Knoop hardness and effectiveness of dual-cured luting systems and flowable resin to bond leucite-reinforced ceramic to enamel. J Prosthodont 2012; 22:54-8. [PMID: 22938145 DOI: 10.1111/j.1532-849x.2012.00898.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
PURPOSE The aim of this study was to evaluate the Knoop microhardness and microshear bond strength (MSBS) of dual-cured luting systems and flowable resin bonded to leucite-reinforced ceramics and enamel. MATERIALS AND METHODS Eighty bovine incisors were randomly divided into four groups per test (microhardness and microshear; n = 10) according to the bonding procedure: Excite DSC/Variolink, Clearfil SE Bond/Panavia F, Adper Scotchbond Multi-Purpose Plus/RelyX ARC, and Adper Single Bond 2/Filtek Z350 Flow. For the KHN measurement, the cement was applied on the enamel surface and light-cured through a ceramic disk (5 mm diameter × 1.2 mm thick). Five indentations were performed in each specimen and measured at HMV-2. For the microshear test, two cylinders of a leucite-reinforced ceramic (1 mm diameter × 2 mm height) were bonded to the enamel substrate in accordance with the bonding procedures previously established. One cylinder was tested 24 hours after cementation, and the other was subjected to thermocycling (2000 cycles) and then submitted to an MSBS test. The data from the hardness and bond strength tests were subjected to one- and two-way repeated-measures analysis of variance (ANOVA), respectively, and to Tukey's test (α= 0.05). RESULTS Scotchbond/RelyX ARC presented higher values of bond strength, while Single Bond/Z350 Flow showed lower values. The thermocycling promoted a reduction in the bond strength values for all groups. Panavia F presented higher values of KHN, and the flowable resin presented the lowest. RelyX ARC and Variolink presented intermediate values on hardness evaluation. CONCLUSIONS For ceramic cementation, dual-cured resin luting systems promoted more reliable bonding and microhardness values than the flowable resin.
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Affiliation(s)
- Lúcia Trazzi Prieto
- Department of Restorative Dentistry, Piracicaba Dental School - State University of Campinas, Piracicaba, Brazil
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