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Go YR, Kim KM, Park SH. Influence of inhomogeneity of the polymerization light beam on the microhardness of resin cement under a CAD-CAM block. J Prosthet Dent 2022; 127:802.e1-802.e10. [PMID: 35272842 DOI: 10.1016/j.prosdent.2022.02.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 02/03/2022] [Accepted: 02/03/2022] [Indexed: 11/30/2022]
Abstract
STATEMENT OF PROBLEM The beam profile of a light polymerization unit shows an inhomogeneous distribution. Therefore, the light passing through indirect restorations may be inhomogeneous and affect the polymerization of the resin cement. PURPOSE The purpose of this in vitro study was to investigate the effects of the inhomogeneous distribution of irradiance passing through a computer-aided design and computer-aided manufacturing (CAD-CAM) block on the microhardness of resin cement. MATERIAL AND METHODS IPS e.max CAD (A3 LT, A3 HT), Celtra Duo (A3 LT), LAVA Ultimate (A3 LT), and Vita Enamic (A3 T) blocks were tested and cut into 1.0-, 1.5-, 2.0-, and 4.0-mm thicknesses (N=100). The resin cements were Variolink N base (light-polymerized) and RelyX U200 (dual-polymerized). The light transmission, irradiance, and beam profile of each block were measured. For microhardness measurement, 5 points (-4 mm, -2 mm, 0 mm, +2 mm, and +4 mm) that coincided with the distance from the center to the periphery of the tip were marked on the specimen's surface. At each point, microhardness was measured 24 hours after polymerization. Repeated measured 1-way ANOVA with the LSD test was performed to analyze the effect of measuring points on the microhardness (α=.05). RESULTS The microhardness of the resin cements decreased with an increase of the CAD-CAM block thickness (P<.05). Resin cements under a 1-mm CAD-CAM block showed relatively uniform microhardness, whereas those under 2-mm and 4-mm blocks showed inhomogeneous microhardness (P<.05). CONCLUSIONS Inhomogeneous light transmission from a light polymerization unit through CAD-CAM blocks resulted in the nonuniform microhardness of resin cement.
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Affiliation(s)
- Yu-Ra Go
- Post graduate student, Department of Conservative of Dentistry, College of Dentistry, Yonsei University, Seoul, Republic of Korea; Resident, Department of Conservative Dentistry, Veterans Health Service Medical Center, Seoul, Republic of Korea
| | - Kwang-Man Kim
- Professor, Department and research Institute of Dental Biomaterials & Bioengineering, BK21 Project, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Sung-Ho Park
- Professor, Department of Conservative of Dentistry and Oral Science Research Center, Yonsei University College of Dentistry, Seoul, Republic of Korea.
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ATEŞ G, HERSEK N. Effect of Composite or Ceramic Thickness on the Polymerization Hardness of 5 Different Dual-cured Resin Luting Cements. CUMHURIYET DENTAL JOURNAL 2021. [DOI: 10.7126/cumudj.970768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Effect of indirect restorative material and thickness on light transmission at different wavelengths. J Prosthodont Res 2019; 63:232-238. [DOI: 10.1016/j.jpor.2018.12.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 11/22/2018] [Accepted: 12/06/2018] [Indexed: 11/18/2022]
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Tuncel İ, Turp I. Effects of coloring procedures on shear bond strength between resin cement and colored zirconia. Eur Oral Res 2019; 52:122-126. [PMID: 30775714 DOI: 10.26650/eor.2018.440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/21/2017] [Accepted: 03/07/2017] [Indexed: 11/20/2022] Open
Abstract
PURPOSE Debonding is expected as a frequent failure type in zirconia restorations. Therefore the aim of the current study is to evaluate the shear bond strength between colored zirconia and resin cement. MATERIALS AND METHODS There were 11 groups evaluated each containing 12 zirconia discs (15 mm x 12 mm x 1.6 mm). Groups were colored with the colors A3, B1, C4, D2, and D4 of the VITA classical shade scale. Coloring procedure was carried out for either 3 second or 60 seconds for the study groups and the control group was left untreated. Specimens were then bonded to translucent resin cement having a thickness of 3 mm and width of 3 mm. The shear bond strength of the samples was measured in a universal testing machine with a crosshead speed of 1 mm per minute. Two-way analysis of variance and Tukey's HSD test were used for pairwise comparisons. Also paired t-test was used for comparing groups with the same color but having different shading times. RESULTS Any significant difference was not found between the shear bond strengths of samples depending on whether color or shading times. Among the groups, B1 (60 seconds of coloring) had the highest bond strength (10.05 MPa), while A3 (60 seconds of coloring) showed the lowest bond strength (6.72 MPa). However, these differences were not statistically significant. CONCLUSION Coloring zirconia did not affect the shear bond strength between zirconia and resin cement.
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Affiliation(s)
- İlkin Tuncel
- Department of Prosthodontics, University of Bezmialem, Faculty of Dentistry, İstanbul, Turkey
| | - Işıl Turp
- Department of Prosthodontics, University of Bezmialem, Faculty of Dentistry, İstanbul, 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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Prieto LT, Pimenta de Araújo CT, Araujo Pierote JJ, Salles de Oliveira DCR, Coppini EK, Sartini Paulillo LAM. Evaluation of degree of conversion and the effect of thermal aging on the color stability of resin cements and flowable composite. JOURNAL OF CONSERVATIVE DENTISTRY : JCD 2018; 21:47-51. [PMID: 29628647 PMCID: PMC5852935 DOI: 10.4103/jcd.jcd_128_17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Purpose: The aim of this in vitro study was to evaluate the color stability and degree of conversion (DC) of dual-cure and light-cure cements and flowable composites after thermal aging. Materials and Methods: A total of 50 human incisors were prepared and divided into six groups (n = 10). Veneers were fabricated using IPS Empress Direct composite resin were bonded with three types of luting agents: Light-cured, conventional dual, and flowable composite according to the manufacturer's instructions. The groups were as follows: Filtek Z350XT Flow/Single Bond 2, RelyX ARC/Single Bond 2, RelyX Veneer/Single Bond 2, Tetric N-Flow/Tetric N-Bond, and Variolink II/Tetric N-Bond. Commission Internationale de l'Éclairage L*, a* and b* color coordinates were measured 24 h after cementation procedure with a color spectrophotometer and reevaluated after 10,000 thermal cycles. To evaluate the DC 50 specimens (n = 10) of each resin material were obtained and Fourier transform infrared spectroscopy was used to evaluate the absorption spectra. Statistical analysis was performed with one-way ANOVA and Tukey's test (α = 0.05). Results: No statistically significant differences in ΔE* occurred after aging. The greatest change in lightness occurred in the Variolink II resin cement. Changes in red–green hue were very small for the same cement and largest in the Tetric N-Flow flowable resin composite, while the greatest change in blue–yellow hue was a yellowing of the RelyX ARC luting cement. RelyX ARC exhibited the highest DC, and there were no statistically significant differences in DC among the other cements. Conclusions: Resin-based luting agent might affect the final of ceramic veneer restorations. The thermal aging affected the final color of the evaluated materials, and these were regarded as clinically unacceptable (ΔE >3.3).
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Affiliation(s)
- Lúcia Trazzi Prieto
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Sao Paulo, Brazil
| | - Cíntia Tereza Pimenta de Araújo
- Department of Dentistry, Faculty of Sciences of Health, Federal University of Jequitinhonha and Mucuri Valley, Diamantina, MG, Brazil
| | - Josué Junior Araujo Pierote
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Sao Paulo, Brazil
| | | | - Erick Kamiya Coppini
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Sao Paulo, Brazil
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Fadanelli MA, Amaral FLBD, Basting RT, Turssi CP, Sotto-Maior BS, França FMG. Effect of Steam Autoclaving on the Tensile Strength of Resin Cements Used for Bonding Two-Piece Zirconia Abutments. J ORAL IMPLANTOL 2017; 43:87-93. [PMID: 27967320 DOI: 10.1563/aaid-joi-d-16-00018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to evaluate the effects of steam autoclave sterilization on the tensile strength of two types of resin cements used to bond customized CAD/CAM zirconia abutments onto titanium bases. Forty sets of zirconia abutments cemented to screwed titanium bases of implants analogs were divided into 4 groups (n = 10). Two groups were treated with a conventional chemically activated resin cement (ML, Multilink Ivoclar Vivadent) and the other two groups with a self-adhesive dual resin cement (RelyX U200, 3M ESPE). One group from each cement was submitted to steam autoclaving. The autoclave sterilization cycle was performed after 72 hours of cementation for 15 minutes at 121°C and 2.1 Kgf/cm2. The samples were subjected to tensile strength testing in a universal testing machine (200 Kgf, 0.5 mm/min), from which the means and standard deviations were obtained in Newtons. Results showed (via ANOVA and Tukey's test; α = 0.05) that in the absence of steam autoclaving, no difference was observed in tensile strength between the cements tested: ML: 344.87 (93.79) and U200: 280 (92.42) (P = .314). Steam autoclaving, however, significantly increased tensile strength for the ML: 465.42 (87.87) compared to U200: 289.10 (49.02) (P < .001). Despite the significant increase in the ML samples (P = .013), autoclaving did not affect the tensile strength of the U200 samples (P > 0.05). The authors concluded that steam autoclaving increases the mean tensile strength of the chemically activated cement compared to the dual-cure self-adhesive cement. The performance of both cements evaluated was similar if the sterilization step was disconsidered.
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Effect of Curing Mode on Shear Bond Strength of Self-Adhesive Cement to Composite Blocks. MATERIALS 2016; 9:ma9030210. [PMID: 28773334 PMCID: PMC5456680 DOI: 10.3390/ma9030210] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Revised: 03/12/2016] [Accepted: 03/15/2016] [Indexed: 11/17/2022]
Abstract
To overcome the disadvantages of computer-aided design/computer-aided manufacturing (CAD/CAM) processed indirect restorations using glass-ceramics and other ceramics, resin nano ceramic, which has high strength and wear resistance with improved polish retention and optical properties, was introduced. The purpose of this study was to evaluate the shear bond strength and fracture pattern of indirect CAD/CAM composite blocks cemented with two self-etch adhesive cements with different curing modes. Sand-blasted CAD/CAM composite blocks were cemented using conventional resin cement, Rely X Ultimate Clicker (RXC, 3M ESPE, St. Paul, MN, USA) with Single Bond Universal (SB, 3M ESPE, St. Paul, MN, USA) for the control group or two self-adhesive resin cements: Rely X U200 (RXU, 3M ESPE, St. Paul, MN, USA) and G-CEM Cerasmart (GC, GC corporation, Tokyo, Japan). RXU and GC groups included different curing modes (light-curing (L) and auto-curing (A)). Shear bond strength (SBS) analyses were performed on all the specimens. The RXC group revealed the highest SBS and the GC A group revealed the lowest SBS. According to Tukey's post hoc test, the RXC group showed a significant difference compared to the GC A group (p < 0.05). For the curing mode, RXU A and RXU L did not show any significant difference between groups and GC A and GC L did not show any significant difference either. Most of the groups except RXC and RXU L revealed adhesive failure patterns predominantly. The RXC group showed a predominant cohesive failure pattern in their CAD/CAM composite, LavaTM Ultimate (LU, 3M ESPE, St. Paul, MN, USA). Within the limitations of this study, no significant difference was found regarding curing modes but more mixed fracture patterns were showed when using the light-curing mode than when using the self-curing mode.
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Sulaiman TA, Abdulmajeed AA, Donovan TE, Ritter AV, Vallittu PK, Närhi TO, Lassila LV. Optical properties and light irradiance of monolithic zirconia at variable thicknesses. Dent Mater 2015. [DOI: 10.1016/j.dental.2015.06.016] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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10
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Cho SH, Lopez A, Berzins DW, Prasad S, Ahn KW. Effect of Different Thicknesses of Pressable Ceramic Veneers on Polymerization of Light-cured and Dual-cured Resin Cements. J Contemp Dent Pract 2015; 16:347-352. [PMID: 26162252 PMCID: PMC4659509 DOI: 10.5005/jp-journals-10024-1688] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
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/cm(2)) 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.
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Affiliation(s)
- Seok-Hwan Cho
- Assistant Professor and Director, Department of General Dental Sciences Predoctoral Prosthodontics and Biomaterials, Marquette University School of Dentistry, 1801 W Wisconsin, Ave, 53233 Milwaukee, Wisconsin, USA, Phone: (414)288-5411, e-mail:
| | - Arnaldo Lopez
- Marquette University School of Dentistry, Milwaukee Wisconsin, USA
| | - David W Berzins
- Department of General Dental Sciences, Graduate Dental Biomaterials, Marquette University School of Dentistry Milwaukee, Wisconsin, USA
| | - Soni Prasad
- Department of General Dental Sciences, Marquette University School of Dentistry, Milwaukee, Wisconsin, USA
| | - Kwang Woo Ahn
- Division of Biostatistics, Medical College of Wisconsin Milwaukee, Wisconsin, USA
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Derceli JDR, Fais LMG, Pinelli LAP. A castor oil-containing dental luting agent: effects of cyclic loading and storage time on flexural strength. J Appl Oral Sci 2015; 22:496-501. [PMID: 25591018 PMCID: PMC4307762 DOI: 10.1590/1678-775720140069] [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: 02/19/2014] [Accepted: 08/08/2014] [Indexed: 11/21/2022] Open
Abstract
Favorable results in the use of castor oil polyurethane (COP) as pulp capping, membrane material, sealer, mouthwash and in bone repair, associated with the fact that Ricinus communis is not derived from petroleum and it is abundant in Brazil, encourage researches in the development of luting agents.
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Affiliation(s)
- Juliana Dos Reis Derceli
- Department of Restorative Dentistry, Ribeirão Preto School of Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Laiza Maria Grassi Fais
- Department of Dental Materials and Prosthodontics, Araraquara Dental School, Universidade Estadual Paulista, Araraquara, SP, Brazil
| | - Lígia Antunes Pereira Pinelli
- Department of Dental Materials and Prosthodontics, Araraquara Dental School, Universidade Estadual Paulista, Araraquara, SP, Brazil
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Mendonça LMD, Pegoraro LF, Lanza MDS, Pegoraro TA, Carvalho RMD. Effects of coronal substrates and water storage on the microhardness of a resin cement used for luting ceramic crowns. J Appl Oral Sci 2014; 22:287-93. [PMID: 25141200 PMCID: PMC4126824 DOI: 10.1590/1678-775720130455] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 04/07/2014] [Indexed: 11/22/2022] Open
Abstract
Composite resin and metallic posts are the materials most employed for reconstruction
of teeth presenting partial or total destruction of crowns. Resin-based cements have
been widely used for cementation of ceramic crowns. The success of cementation
depends on the achievement of adequate cement curing.
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Affiliation(s)
| | - Luiz Fernando Pegoraro
- Department of Prosthodontics, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil
| | | | | | - Ricardo Marins de Carvalho
- Department of Oral Biological and Medical Sciences Division of Biomaterials, Frontier Clinical Research Centre, Faculty of Dentistry, University of British Columbia, Vancouver, BC, Canada
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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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Zaruba M, Göhring TN, Wegehaupt FJ, Attin T. Influence of a proximal margin elevation technique on marginal adaptation of ceramic inlays. Acta Odontol Scand 2013; 71:317-24. [PMID: 23004362 DOI: 10.3109/00016357.2012.680905] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE Evaluating the effect of a proximal margin elevation technique on marginal adaptation of ceramic inlays. METHODS Class II MOD-cavities were prepared in 40 human molars and randomly distributed to four groups (n = 10). In group EN (positive control) proximal margins were located in enamel, 1 mm above the cementoenamel junction, while 2 mm below in groups DE-1In, DE-2In and DE. The groups DE-1In, DE-2In and DE simulated subgingival location of the cervical margin. In group DE-1In one 3 mm and in group DE-2In two 1.5 mm composite layers (Tetric) were placed for margin elevation of the proximal cavities using Syntac classic as an adhesive. The proximal cavities of group DE remained untreated and served as a negative control. In all groups, ceramic inlays (Cerec 3D) were adhesively inserted. Replicas were taken before and after thermomechanical loading (1.200.000 cycles, 50/5°C, max. load 49 N). Marginal integrity (tooth-composite, composite-inlay) was evaluated with scanning electron microscopy (200×). Percentage of continuous margin (% of total proximal margin length) was compared between groups before and after cycling using ANOVA and Scheffé post-hoc test. RESULTS After thermomechanical loading, no significant differences were observed between the different groups with respect to the interface composite-inlay and tooth-composite with margins in dentin. The interface tooth-composite in enamel of group EN was significantly better compared to group DE-2In, which was not different to the negative control group DE and DE-1In. CONCLUSION Margin elevation technique by placement of a composite filling in the proximal box before insertion of a ceramic inlay results in marginal integrities not different from margins of ceramic inlays placed in dentin.
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Hong SO, Oh Y, Min JB, Kim JW, Lee BN, Hwang YC, Hwang IN, Oh WM, Chang HS. Power density of various light curing units through resin inlays with modified layer thickness. Restor Dent Endod 2013; 37:130-5. [PMID: 23431061 PMCID: PMC3569396 DOI: 10.5395/rde.2012.37.3.130] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 02/13/2012] [Accepted: 02/17/2012] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVES The purpose of this study was to enhance curing light penetration through resin inlays by modifying the thicknesses of the dentin, enamel, and translucent layers. MATERIALS AND METHODS To investigate the layer dominantly affecting the power density of light curing units, resin wafers of each layer with 0.5 mm thickness were prepared and power density through resin wafers was measured with a dental radiometer (Cure Rite, Kerr). The dentin layer, which had the dominant effect on power density reduction, was decreased in thickness from 0.5 to 0.1 mm while thickness of the enamel layer was kept unchanged at 0.5 mm and thickness of the translucent layer was increased from 0.5 to 0.9 mm and vice versa, in order to maintain the total thickness of 1.5 mm of the resin inlay. Power density of various light curing units through resin inlays was measured. RESULTS Power density measured through 0.5 mm resin wafers decreased more significantly with the dentin layer than with the enamel and translucent layers (p < 0.05). Power density through 1.5 mm resin inlays increased when the dentin layer thickness was reduced and the enamel or translucent layer thickness was increased. The highest power density was recorded with dentin layer thickness of 0.1 mm and increased translucent layer thickness in all light curing units. CONCLUSIONS To enhance the power density through resin inlays, reducing the dentin layer thickness and increasing the translucent layer thickness would be recommendable when fabricating resin inlays.
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Affiliation(s)
- Sung-Ok Hong
- Department of Conservative Dentistry, Wonkwang University College of Dentistry and Dental Research Institute, Iksan, Korea
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The Effects of Different Adhesive Agents on the Shear Bond Strength of a Self-Adhesive Resin Cement. J Appl Biomater Funct Mater 2012; 10:149-56. [DOI: 10.5301/jabfm.2012.9255] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/27/2012] [Indexed: 11/20/2022] Open
Abstract
Purpose To compare the clinical success of a self-adhesive resin cement used in combination with different adhesive bonding systems with that of a conventional dual-cure resin cement. Methods The study was performed with 136 freshly extracted molars embedded in acrylic resin blocks and 136 IPS e.max Press discs. Teeth and discs were randomly divided into four equal groups and cemented together using either RelyX ARC (ARC), RelyX Unicem (Unicem), RelyX Unicem+Adper-Prompt L-pop (L-pop), or RelyX and Unicem+Total-etch (Total-etch). Shear bond strength measurements were obtained before and after thermocycling. Following bond testing, the surfaces of one sample per subgroup (thermocycled and non-thermocycled), were assessed using scanning electron microscopy (SEM). Results Among the non-thermocylced subgroups, ARC exhibited the highest bond strength values, followed by Total Etch, Unicem and L-pop. ARC also exhibited the highest bond strength values among the thermocycled subgroups, followed by Unicem, Total-etch, and L-pop. SEM analysis clearly revealed the negative effects of thermo-cycling on the mechanical properties of adhesive agents. Conclusions RelyX Unicem may be preferable in many cases because of its simplified application and reduced technique-sensitivity.
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Oliveira M, Cesar PF, Giannini M, Rueggeberg FA, Rodrigues J, Arrais CA. Effect of temperature on the degree of conversion and working time of dual-cured resin cements exposed to different curing conditions. Oper Dent 2012; 37:370-9. [PMID: 22816499 DOI: 10.2341/11-198-l] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES This study evaluated the degree of conversion (DC) and working time (WT) of two commercial, dual-cured resin cements polymerized at varying temperatures and under different curing-light accessible conditions, using Fourier transformed infrared analysis (FTIR). MATERIALS AND METHODS Calibra (Cal; Dentsply Caulk) and Variolink II (Ivoclar Vivadent) were tested at 25°C or preheated to 37°C or 50°C and applied to a similar-temperature surface of a horizontal attenuated-total-reflectance unit (ATR) attached to an infrared spectrometer. The products were polymerized using one of four conditions: direct light exposure only (600 mW/cm(2)) through a glass slide or through a 1.5- or 3.0-mm-thick ceramic disc (A2 shade, IPS e.max, Ivoclar Vivadent) or allowed to self-cure in the absence of light curing. FTIR spectra were recorded for 20 min (1 spectrum/s, 16 scans/spectrum, resolution 4 cm(-1)) immediately after application to the ATR. DC was calculated using standard techniques of observing changes in aliphatic-to-aromatic peak ratios precuring and 20-min postcuring as well as during each 1-second interval. Time-based monomer conversion analysis was used to determine WT at each temperature. DC and WT data (n=6) were analyzed by two-way analysis of variance and Tukey post hoc test (p=0.05). RESULTS Higher temperatures increased DC regardless of curing mode and product. For Calibra, only the 3-mm-thick ceramic group showed lower DC than the other groups at 25°C (p=0.01830), while no significant difference was observed among groups at 37°C and 50°C. For Variolink, the 3-mm-thick ceramic group showed lower DC than the 1-mm-thick group only at 25°C, while the self-cure group showed lower DC than the others at all temperatures (p=0.00001). WT decreased with increasing temperature: at 37°C near 70% reduction and at 50°C near 90% for both products, with WT reduction reaching clinically inappropriate times in some cases (p=0.00001). CONCLUSION Elevated temperature during polymerization of dual-cured cements increased DC. WT was reduced with elevated temperature, but the extent of reduction might not be clinically acceptable.
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Affiliation(s)
- M Oliveira
- Department of Operative Dentistry, University of Guarulhos, Guarulhos, Brazil
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Archegas LRP, de Menezes Caldas DB, Rached RN, Soares P, Souza EM. Effect of Ceramic Veneer Opacity and Exposure Time on the Polymerization Efficiency of Resin Cements. Oper Dent 2012; 37:281-9. [DOI: 10.2341/11-134-l] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
The objective of this study was to determine the degree of conversion (DC), hardness (H), and modulus of elasticity (E) of a dual-cured resin cement, a light-cured resin cement, and a flowable resin cured through opaque or translucent ceramic with different exposure times. RelyX ARC (dual), RelyX Veneer (light-cured), and Filtek Z350 Flow resin specimens 0.5 mm thick were cured for 40, 80, and 120 seconds through 1-mm thick translucent or opaque feldspathic ceramic disks (n=10). The specimens were stored at 37°C for 24 hours. Half of each specimen was used to test the DC and the other half to test H and E. The DC was determined in a Fourier transform infrared spectrometer in absorbance mode at peaks of 1638 cm−1 and 1610 cm−1. H and E were determined using nanoindentation with one loading cycle and a maximum load of 400 mN. The data were analyzed with three-way analysis of variance (ANOVA), the Games-Howell test, and the Pearson correlation test (α=0.05). Statistically significant differences were found for all three factors (material, opacity, and exposure time), as well as interaction between them. The opaque ceramic resulted in lower DC, H, and E than the translucent ceramic for an exposure time of 40 seconds. An exposure time of 120 seconds resulted in a similar DC for all materials, irrespective of the opacity of the ceramic. Materials cured for 120 seconds had higher H and E than those cured for 40 seconds. The exposure time and opacity of the ceramic exerted an influence on the DC, H, and E of the materials evaluated.
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Lee JW, Cha HS, Lee JH. Curing efficiency of various resin-based materials polymerized through different ceramic thicknesses and curing time. J Adv Prosthodont 2011; 3:126-31. [PMID: 22053242 PMCID: PMC3204447 DOI: 10.4047/jap.2011.3.3.126] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Revised: 05/24/2011] [Accepted: 06/07/2011] [Indexed: 11/08/2022] Open
Abstract
PURPOSE The aim of this in vitro study was to examine the curing efficiency of various resin-based materials polymerized through ceramic restorations with 3 different thicknesses. Curing efficiency was evaluated by determining the surface microhardness (VHN) of the resin specimens. MATERIALS AND METHODS Four kinds of resin materials were used. Z350 (3M ESPE Filtek™ Z350: A2 Shade), Z250 (3M ESPE Filtek™ Z250: A2 Shade) and Variolink® II (VL: Ivoclar vivadent, base: transparent) either with or without a self-curing catalyst (VLC: Ivoclar vivadent, catalyst: low viscosity/transparent) were filled into the silicone mold (10 mm diameter, 1 mm thick). They were cured through ceramic discs (IPS e.max Press MO-0 ingot ivoclar vivadent, 10 mm diameter, 0.5, 1 and 2 mm thicknesses) by LED light-curing units for 20 and 40 seconds. Vicker's microhardness numbers (VHNs) were measured on the bottom surfaces by a microhardness tester. Data were analyzed using a 3- way analysis of variance (ANOVA) at a significance level of 0.05. RESULTS The thickness of ceramic disc increased, the VHNs of all four resin types were decreased (P<.05). The mean VHN values of the resins light cured for 40 seconds were significantly higher than that of LED for 20 seconds in all four resin materials (P<.05). VLC showed significantly higher VHN values than VL regardless of other conditions (P<.05). Z350 and Z250 showed higher values than VL or VLC (P<.01). CONCLUSION Thinner ceramic disc with increased curing time resulted higher VHN values of all resin materials. The use of a catalyst produced a greater hardness with all polymerization methods. Restorative resin materials (Z350, Z250) showed higher VHN values than resin cement materials (VL, VLC).
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Affiliation(s)
- Jung-Won Lee
- Department of Dentistry, College of Medicine, University of Ulsan, Ulsan, Korea
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Kilinc E, Antonson SA, Hardigan PC, Kesercioglu A. The effect of ceramic restoration shade and thickness on the polymerization of light- and dual-cure resin cements. Oper Dent 2011; 36:661-9. [PMID: 21913860 DOI: 10.2341/10-206-l] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
OBJECTIVES Inadequately polymerized resin cements may negatively affect the clinical performance of cemented all-ceramic restorations. The purpose of this in vitro study was to evaluate the effect of ceramic thickness and shade on the microhardness of various light-cured (LC) and dual-cured (DC) resin cements. The amount of light transmission through the restoration was also evaluated to correlate the results. METHODS Three different brands of resin cements (Appeal/Ivoclar; Calibra/Dentsply; Nexus 2/Kerr) were used in LC and DC forms to prepare disk-shaped samples (0.5-mm thickness × 5-mm diameter) (n=15). Study group samples were light-cured for 40 seconds (Flashlite 1401/Discus Dental) through four shades (ETC1, ETC2, ETC3, ETC4) and four thicknesses (1 mm, 2 mm, 3 mm, 4 mm) of all-ceramic ingot discs (IPS Empress Esthetic/Ivoclar). Control samples were directly cured without the presence of ceramic. The light transmission through various shades and thicknesses of ceramics was measured using a hand-held radiometer (Demetron, Kerr). Vickers microhardness measurements were performed (Micromet/Buehler) at 24 hours following dark storage in 37°C water. Correlation between ceramic shade, thickness, and light intensity readings (mW/cm2) with respect to microhardness was statistically evaluated using analysis of variance (p=0.05). RESULTS Ceramic thickness of 3 mm and/or above significantly decreased the microhardness values in all LC and DC groups (p<0.0001). Ceramic shade had a significant effect only on Calibra in both LC and DC groups (p<0.0001). Microhardness values of LC groups were significantly lower than DC groups (p<0.0001). Control groups had significantly higher hardness values in all cement groups (p<0.0001). There was a significant correlation between the amount of light transmitted and hardness (p=0.000). CONCLUSION The ceramic thickness has a more intense effect on polymerization compared to the ceramic shade. Overlying ceramic thickness of 3 mm and above was found to adversely affect the polymerization of LC and DC resin cements and therefore a 3-mm thickness was considered the critical threshold.
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Affiliation(s)
- E Kilinc
- Nova Southeastern University College of Dental Medicine, Cariology and Restorative Dentistry, Fort Lauderdale, FL, USA
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Lohbauer U, Pelka M, Belli R, Schmitt J, Mocker E, Jandt KD, Müller FA. Degree of Conversion of Luting Resins Around Ceramic Inlays in Natural Deep Cavities: A Micro-Raman Spectroscopy Analysis. Oper Dent 2010; 35:579-86. [PMID: 20945750 DOI: 10.2341/10-012-l] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
Contrary to previous evidence, the degrees of conversion of resin luting materials have been shown to reach statistically similar values in three different depths around ceramic inlays luted to natural cavities. Both dual-cure and light-cure materials have presented conversion homogeneity, although they have been shown to be material-dependent.
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Affiliation(s)
- Ulrich Lohbauer
- Dental Clinic 1, Dental Materials Lab, Friedrich-Alexander-University of Erlangen, Erlangen, Germany.
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Wegehaupt FJ, Betschart J, Attin T. Effect of sodium hypochlorite contamination on microhardness of dental core build-up materials. Dent Mater J 2010; 29:469-74. [PMID: 20668360 DOI: 10.4012/dmj.2010-007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study aimed to determine the influence of sodium hypochlorite (NaOCl) contamination on the microhardness of build-up composites. Fifty-two samples, from each of three build-up materials (LuxaCore Dual, MultiCore flow and Rebilda DC) were prepared. Half of the samples from each material were stored in physiologic saline (baseline control) while the other halves were stored in NaOCl. After 1 h, the samples were rinsed with tap water, cut axially and measured for Knoop hardness at different depth levels. The results were analysed by ANOVA and unpaired t-tests (p<0.05). Significant differences in microhardness were observed for LuxaCore Dual up to 0.2 mm, Rebilda DC up to 0.3 mm, and for MultiCore flow up to 0.4 mm under the surface level. Contact with sodium hypochlorite on build-up materials causes reduction of the microhardness. The softening is not only limited on the surface, but can also be found in deeper layers of build-up materials.
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Affiliation(s)
- Florian Just Wegehaupt
- Clinic for Preventive Dentistry, Periodontology and Cariology, University Zurich, Switzerland.
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Aguiar TR, Di Francescantonio M, Arrais CAG, Ambrosano GMB, Davanzo C, Giannini M. Influence of curing mode and time on degree of conversion of one conventional and two self-adhesive resin cements. Oper Dent 2010; 35:295-9. [PMID: 20533629 DOI: 10.2341/09-252-l] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study evaluated the effect of curing mode (auto- and dual-polymerizing mode) and time interval (5, 10 and 15 minutes) on the degree of conversion of resin cements. One conventional dual-cured resin cement (Panavia F 2.0 [Kuraray Medical Inc]) and two self-adhesive cements (RelyX Unicem [3M ESPE] and BisCem [BISCO, Inc]) were evaluated. The products (n = 5) were manipulated according to the manufacturer's instructions and applied to the surface of a horizontal attenuated reflectance unit attached to an infrared spectrometer. The materials were either light-cured for 40 seconds (dual-polymerizing mode) or allowed to auto-polymerize. The degree of conversion was calculated according to changes in the aliphatic-to-aromatic peak ratios prior to and 5, 10 and 15 minutes after light-activation or after mixing when the specimens were allowed to auto-polymerize. Data (%) were analyzed by two-way repeated measure ANOVA (curing mode and time interval) and Tukey's post-hoc test (alpha = 0.05%). The light-activating mode led to a higher degree of conversion values than the self-curing mode in self-adhesive cements (RelyX Unicem and BisCem), while there was no difference in the degree of conversion between the self- and light-cured groups of Panavia F 2.0 resin cement. All products showed a higher degree of conversion at 15 minutes postcuring than any other evaluation interval. The self-adhesive cements provide a higher degree of conversion values when light-activated. After 15 minutes of polymerization initiation, the degree of conversion was higher in all resin cements, regardless of the curing mode.
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Pereira SG, Fulgêncio R, Nunes TG, Toledano M, Osorio R, Carvalho RM. Effect of curing protocol on the polymerization of dual-cured resin cements. Dent Mater 2010; 26:710-8. [DOI: 10.1016/j.dental.2010.03.016] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 12/15/2009] [Accepted: 03/09/2010] [Indexed: 10/19/2022]
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Arrais CAG, Kasaz ADC, Albino LGB, Rodrigues JA, Reis AF. Effect of curing mode on the hardness of dual-cured composite resin core build-up materials. Braz Oral Res 2010; 24:245-9. [DOI: 10.1590/s1806-83242010000200019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Accepted: 09/08/2009] [Indexed: 11/22/2022] Open
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Hooshmand T, Mahmoodi N, Keshvad A. Microhardness of a resin cement polymerized by light-emitting diode and halogen lights through ceramic. J Prosthodont 2009; 18:411-6. [PMID: 19486456 DOI: 10.1111/j.1532-849x.2009.00449.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
PURPOSE This study evaluated the curing efficiency of light-emitting diode (LED) and halogen [quartz tungsten halogens (QTH)] lights through ceramic by determining the surface microhardness of a highly filled resin cement. MATERIALS AND METHODS Resin cement specimens (Variolink Ultra; with and without catalyst) (5-mm diameter, 1-mm thick) were condensed in a Teflon mold. They were irradiated through a ceramic disc (IPS Empress 2, diameter 5 mm, thickness 2 mm) by high-power light-curing units as follows: (1) QTH for 40 seconds (continuous), (2) LED for 20 seconds, and (3) LED for 40 seconds (5-second ramp mode). The specimens in control groups were cured under a Mylar strip. Vickers microhardness was measured on the top and bottom surfaces by a microhardness tester. Data were analyzed using analysis of variance (ANOVA) and a post hoc Bonferroni test at a significance level of p < 0.05. RESULTS The mean microhardness values of the top and bottom surfaces for the dual-cured cement polymerized beneath the ceramic by QTH or LED (40 seconds) were significantly higher than that of light-cured cement (p < 0.05). The top and bottom surface microhardness of dual-cured cement polymerized beneath the ceramic did not show a statistically significant difference between the LED and QTH for 40 seconds (p > 0.05). CONCLUSIONS The efficiency of high-power LED light in polymerization of the resin cement used in this study was comparable to the high-power QTH light only with a longer exposure time. A reduced curing time of 20 seconds with high-power LED light for photopolymerizing the dual-cured resin cement under ceramic restorations with a minimum 2-mm thickness is not recommended.
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Affiliation(s)
- Tabassom Hooshmand
- Department of Dental Materials, School of Dentistry/Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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Arrais CAG, Giannini M, Rueggeberg FA. Kinetic analysis of monomer conversion in auto- and dual-polymerizing modes of commercial resin luting cements. J Prosthet Dent 2009; 101:128-36. [PMID: 19167537 DOI: 10.1016/s0022-3913(09)60008-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Cesar A G Arrais
- Department of Operative Dentistry, School of Dentistry, University of Guarulhos, Guarulhos, São Paulo, Brazil.
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Moraes RR, Brandt WC, Naves LZ, Correr-Sobrinho L, Piva E. Light- and time-dependent polymerization of dual-cured resin luting agent beneath ceramic. Acta Odontol Scand 2008; 66:257-61. [PMID: 18618339 DOI: 10.1080/00016350802241563] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
OBJECTIVE In this study we investigated the degree of conversion (DC) of a dual-cured resin luting agent beneath a ceramic of different thickness. MATERIAL AND METHODS The luting material (RelyX) was photo-activated for 40s through ceramic disks (Empress Esthetic, 0.7, 1.4, or 2mm thick). Dual (DUC) and chemically cured (CC) control groups were obtained. A delayed exposure (DE) procedure was tested in which the material was light-activated after 5 min without using ceramic. DC (%) was measured using infrared spectroscopy at 40 s, 1, 2, 4, 6, 8, and 10 min. Light irradiance and spectrum transmitted through ceramic were measured using a power meter and a spectrometer. RESULTS A decrease in irradiance was detected with increasing ceramic thickness, but no alteration in the emission profile was observed. At 10 min, all groups showed DC higher than at 40s. No significant differences were detected for DUC compared with the groups indirectly activated through the ceramic disks. Generally, CC showed the lowest DC values. No significant effect in DC was detected for DE after 10 min. A significant increase in DC was generally detected only up to 4 min. CONCLUSIONS The luting agent was dependent on light exposure and time to obtain improved DC. Neither the indirect activation nor the DE procedure significantly influenced the final DC.
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Hofmann N, Papsthart G, Hugo B, Klaiber B. Comparison of photo-activation versus chemical or dual-curing of resin-based luting cements regarding flexural strength, modulus and surface hardness. J Oral Rehabil 2008. [DOI: 10.1111/j.1365-2842.2001.00809.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Arrais CA, Rueggeberg FA, Waller JL, de Goes MF, Giannini M. Effect of curing mode on the polymerization characteristics of dual-cured resin cement systems. J Dent 2008; 36:418-26. [PMID: 18395315 DOI: 10.1016/j.jdent.2008.02.014] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 02/20/2008] [Accepted: 02/21/2008] [Indexed: 10/22/2022] Open
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Reges RV, Moraes RR, Correr AB, Sinhoreti MAC, Correr-Sobrinho L, Piva E, Nouer PRA. In-depth polymerization of dual-cured resin cement assessed by hardness. J Biomater Appl 2008; 23:85-96. [PMID: 18194995 DOI: 10.1177/0885328207086316] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study investigates the in-depth polymerization of dual-cured resin cement (Enforce; Dentsply, shades A2, B1, and opaque). Cylindrical specimens are obtained by photo-activation through ceramic. Control samples are light-cured without using ceramic. Samples are tested after 15 min or 24 h. Knoop hardness readings are made at 100, 300, 500, and 700 microm depth. Hardness is generally dependent on the mode of activation and post-cure time. Shades A2 and B1 show higher hardness values than opaque resin. Hardness at 100 microm is higher than at 700 microm. A linear relationship between hardness and depth is observed.
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Affiliation(s)
- Rogério V Reges
- Department of Restorative Dentistry, Dental Materials Division Piracicaba Dental School, State University of Campinas Av. Limeira, 901 - 13414-903 - Piracicaba, SP, Brazil
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Karaagaclioglu L, Yilmaz B. Influence of Cement Shade and Water Storage on the Final Color of Leucite-reinforced Ceramics. Oper Dent 2008; 33:386-91. [DOI: 10.2341/07-61] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
Luting cement under 0.8 mm thick leucite-reinforced ceramic changed the final color of the ceramic and could be seen by the human eye. Therefore, clinicians may prefer to use try-in pastes or polymerized luting composite shade guides to compensate for the change in color of definitive restorations, such as laminate veneers. The final color differences between ceramics luted with cements in A1 and A3 shades were not clinically perceivable at each measurement. Within the limitations of this study, changing the color of an IPS Empress laminate veneer restoration via the shade of the cement seems not to be a preferred method.
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Tango RN, Sinhoreti MAC, Correr AB, Correr-Sobrinho L, Henriques GEP. Effect of Light-Curing Method and Cement Activation Mode on Resin Cement Knoop Hardness. J Prosthodont 2007; 16:480-4. [PMID: 17760867 DOI: 10.1111/j.1532-849x.2007.00234.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
PURPOSE To evaluate the Knoop hardness (KHN) of the resin cement Enforce activated by chemical/physical mode or physical mode solely; light-cured directly or through a 1.5 mm thick ceramic disc (HeraCeram) on shade DD2. MATERIALS AND METHODS Light-curing was carried out using a conventional quartz tungsten halogen light (QTH) (XL2500) for 40 seconds at 700 mW/cm(2); light-emitting diodes (LED) (Ultrablue Is) for 40 seconds at 440 mW/cm(2); and Xenon plasma arc (PAC) (Apollo 95E) for 3 seconds at 1600 mW/cm(2). Bovine incisors had their buccal faces flattened and hybridized. A mold was seated on these surfaces and filled with cement. A disc of the acid-etched and silanized veneering material was seated over this set for light-curing. After dry storage (24 hours at 37 degrees C), specimens (n= 10) were sectioned for KHN measurements performed in a microhardness tester (50 gf load for 15 seconds). Data were submitted to ANOVA and Tukey's test (alpha= 0.05). RESULTS The highest KHN values were obtained with LED, for both dual-cured and light-cured cement. The lowest KHN value was obtained with light-cured PAC. Light-curing with QTH resulted in hardness values similar to PAC in dual-cured groups. CONCLUSIONS Light-curing through HeraCeram can influence resin cement hardness.
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Affiliation(s)
- Rubens Nisie Tango
- Department of Restorative Dentistry, Piracicaba Dental School-UNICAMP, Sao Paulo, Brazil
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Yoshida K, Tsuo Y, Meng X, Atsuta M. Mechanical Properties of Dual-Cured Resin Luting Agents for Ceramic Restoration. J Prosthodont 2007; 16:370-6. [PMID: 17672836 DOI: 10.1111/j.1532-849x.2007.00221.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
PURPOSE The aim of the present study was to evaluate mechanical properties, including surface hardness, flexural strength, and flexural modulus, of two dual-cured resin luting agents [Clearfil Esthetic Cement (CEC) and Variolink II (VLII)] irradiated through four thicknesses of leucite ceramics (0, 1, 2, and 3 mm) and to evaluate their shear bond strength to zirconia ceramic (Cercon) using each ceramic primer. MATERIALS AND METHODS Knoop hardness was measured on a thin layer of resin luting agent on the ceramic surface. Three-point bending tests were performed after 24 hours of storage at 37 degrees C. Two differently shaped zirconia ceramic specimens with or without sandblasting with alumina were treated with each primer. The specimens were then cemented together with each resin luting agent. Half of the specimens were stored in water at 37 degrees C for 24 hours and the other half were thermocycled 5000 times. RESULTS VLII revealed statistically higher Knoop hardness and flexural modulus than CEC for each thickness of ceramic. No significant differences in flexural strength were observed between VLII and CEC for each ceramic spacer. Reduction of the mechanical properties with increase of ceramic thickness varied for each property; however, these properties were similar in the two materials. Blasting with alumina was significantly effective for increasing shear bond strength of both resin luting agents before and after thermal cycling. The use of Clearfil Ceramic Primer showed the highest shear bond strength and maintained bond durability after 5000 thermocycles. CONCLUSION Mechanical properties of CEC dual-cured resin luting agent appear adequate for ceramic restorations.
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Affiliation(s)
- Keiichi Yoshida
- Nagasaki University Graduate School of Biomedical Sciences-Applied Prosthodontics, Nagasaki, Japan.
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Arrais CAG, Giannini M, Rueggeberg FA, Pashley DH. Effect of curing mode on microtensile bond strength to dentin of two dual-cured adhesive systems in combination with resin luting cements for indirect restorations. Oper Dent 2007; 32:37-44. [PMID: 17288327 DOI: 10.2341/06-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study evaluated the microtensile bond strength (microTBS) of dual-cured adhesive systems when the different components were either light activated or left in the uncured state prior to cementation of an indirect composite restoration. Occlusal dentin surfaces of 40 human third molars were flattened. The teeth were randomly assigned to 8 groups (n = 5) according to the dual-cured systems (bonding agents/resin cements) and curing modes: All Bond 2/Duolink (AB2-BISCO Inc) and Optibond Solo Plus Dual Cure/Nexus 2 (SOLO-Kerr). Resin cements were applied to pre-cured resin composite discs (2 mm thick/Z-250/3M ESPE), which were fixed to dentin surfaces containing adhesive resin in either cured (LP) or uncured states (SP). The restored teeth were light activated according to the manufacturers' instructions (LRC-XL3000/3M ESPE) or allowed to self-cure (SRC). The restored teeth were water-stored at 37 degrees C for 24 hours. They were then both mesial-distally and buccal-lingually sectioned to obtain bonded specimens (1.2 mm2). Each specimen was tested in tension at a crosshead speed of 0.6 mm/minute until failure. Data (MPa (SD)) were analyzed by two-way ANOVA and Tukey's post-hoc test (p < .05). AB2/SP exhibited higher microTBS than AB2/LP (p = .00001); however, no significant differences were noted between SOLO/LP and SOLO/SP. Results suggested that dual-cured adhesive systems were as strong or even stronger when they were left in the uncured state prior to indirect resin composite cementation.
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Arrais CAG, Giannini M, Rueggeberg FA, Pashley DH. Microtensile bond strength of dual-polymerizing cementing systems to dentin using different polymerizing modes. J Prosthet Dent 2007; 97:99-106. [PMID: 17341378 DOI: 10.1016/j.prosdent.2006.12.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
STATEMENT OF THE PROBLEM The effectiveness of bond strength using dual-polymerizing cementing systems ([DCSs] defined as the combination of dual-polymerizing bonding agents and resin cements) used with indirect restorations has not been evaluated when used solely with the autopolymerizing mode. PURPOSE This study evaluated the in vitro microtensile bond strength (MTBS) of fourth- and fifth-generation DCSs with indirect composite restorations either light polymerized or autopolymerized. MATERIAL AND METHODS Occlusal dentin surfaces of 48 human third molars were exposed and flattened. Teeth were assigned to 8 groups (n=6) according to the DCS and polymerizing modes: All-Bond2/Duolink (AB2), Optibond/Nexus2 (OPT), Bond1/Lute-it (B1), and Optibond Solo Dual Cure/Nexus2 (SOLO). Bonding agents were applied to dentin surfaces and left in the unpolymerized state. Resin cements were applied to prepolymerized resin discs (2 mm thick/Z250), which were subsequently bonded to the dentin surfaces. The restored teeth were light polymerized according to manufacturers' instructions (PP/XL 3000) or allowed to autopolymerize (AP). Restored teeth were stored in water at 37 degrees C for 24 hours and were both mesio-distally and bucco-lingually sectioned to obtain multiple bonded beams (1.2 mm2 of cross-sectional area). Each specimen was tested in tension at a crosshead speed of 0.6 mm/min until failure. Data (MPa) were analyzed by 2-way analysis of variance and the Tukey post hoc test (alpha=.05). Failure patterns of tested specimens were analyzed using scanning electron microscopy. RESULTS The mean (SD) MTBS values (MPa) were: AB2/PP: 36.9 (6.5); AB2/AP: 32.7 (7.3); B1/PP: 38.2 (7.0); B1/AP: 13.0 (4.2); SOLO/PP: 33.2 (7.2); SOLO/AP: 23.4 (3.4); OPT/PP: 30.8 (7.5); OPT/AP: 13.1 (5.8). The AP groups showed significantly lower MTBS than the PP groups (P<.0001), except for AB2, which showed no difference between polymerization modes (P=.2608). CONCLUSION The autopolymerizing mode of some dual-polymerizing cement systems may not be effective in promoting bond strength.
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Affiliation(s)
- Cesar A G Arrais
- Department of Restorative Dentistry, Piracicaba School of Dentistry, University of Campinas, Piracicaba, Brazil
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Piwowarczyk A, Bender R, Ottl P, Lauer HC. Long-term bond between dual-polymerizing cementing agents and human hard dental tissue. Dent Mater 2007; 23:211-7. [PMID: 16494937 DOI: 10.1016/j.dental.2006.01.012] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2005] [Accepted: 01/10/2006] [Indexed: 10/25/2022]
Abstract
OBJECTIVES To examine the long-term adhesion of seven dual-polymerizing cementing agents to human dentin in vitro. METHODS Two hundred and eighty extracted non-carious human molars were ground flat to expose dentin surfaces. The bond strengths of cementing agents with their respective bonding systems were examined: one compomer cement (PermaCem), five resin cements (RelyX ARC, Panavia F, Variolink II, Nexus 2, Calibra) and one self-adhesive universal resin cement (RelyX Unicem). One subgroup (n=10) was tested after 150 days of storage in water at 37 degrees C (time t(1)), the other subgroup (n=10) was tested after 150 days of storage plus 37,500 thermal cycles (time t(2)). All specimens were stressed in shear at a constant crosshead speed of 0.5mm/min until failure. Statistical analysis was performed by ANOVA, taking effect interactions into account. The Tukey method was used for multiple paired comparisons (alpha=0.05). RESULTS The three-way ANOVA (cementing agents, polymerization methods, times of measurements) showed Variolink II to have the highest strength at 9.9+/-4.5MPa. Values were slightly higher at t(1) (5.9+/-4.7MPa) than at t(2) (4.9+/-4.2MPa) (p=0.0044). Polymerization with light activation (6.5+/-5.1MPa) yielded higher strengths than polymerization without (4.3+/-3.3MPa) (p<0.0001). Separate two-way ANOVAs for t(1) and t(2) showed that the two main effects (cementing agent, polymerization method) and their interactions differed significantly. SIGNIFICANCE Cementing agents/adhesive systems and the polymerization method influence the long-term bond to hard dental tissues.
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Affiliation(s)
- Andree Piwowarczyk
- Department of Prosthodontics, School of Dentistry, Johann Wolfgang Goethe University of Frankfurt/Main, Germany.
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Peixoto RTRC, Paulinelli VMF, Sander HH, Lanza MD, Cury LA, Poletto LTA. Light transmission through porcelain. Dent Mater 2007; 23:1363-8. [PMID: 17207526 DOI: 10.1016/j.dental.2006.11.025] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2006] [Revised: 07/07/2006] [Accepted: 11/16/2006] [Indexed: 10/23/2022]
Abstract
OBJECTIVE This study evaluates the effect of shade and thickness of porcelain in light transmission. METHODS One hundred and twenty-eight disks of Duceram porcelain were made to combine four different thicknesses (1.5; 2.0; 3.0; 4.0 mm) and eight shades (A(1); A(4); B(1); B(4); C(1); C(4); D(2); D(4)). A digital power meter (Newport Optical Power Meter was used to measure light transmission. The porcelain transmission coefficient was calculated using Lambert-Beer law, t(c)=Ce(-alphad), where t(c) is the transmission coefficient, C the contribution factor of the reflection coefficient, e a constant, alpha the absorption coefficient and d is the sample thickness. RESULTS The transmission coefficients did not vary statistically in relation to the two visible light-curing units studied. From all the samples, the colors A(1) and D(2), thickness 1.5 mm, presented the highest percentages of transmission (8%) and the shades, A(4), B(4) and C(4), thickness 4 mm, the lowest (0.5%). The relationship between the Naperian logarithm of the transmission coefficient and the samples thickness followed the Lambert-Beer law. The linear adjustment of the experimental points of the two variables, showed the absorption coefficient (alpha) and the constant value related to the reflection (C) of each porcelain shade. The reflection coefficient values of all shades did not vary statistically among themselves. SIGNIFICANCE For most shades there was a significant decrease in light transmission as the sample porcelain thickness increased. For the same thickness most shades presented statistical difference between the transmission coefficients. However, the larger the thickness, the higher the number of shades which, statistically, showed no difference.
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Affiliation(s)
- Rogéli T R C Peixoto
- Department of Restorative Dentistry, Federal University of Minas Gerais, Belo Horizonte, Brazil.
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Hikita K, Van Meerbeek B, De Munck J, Ikeda T, Van Landuyt K, Maida T, Lambrechts P, Peumans M. Bonding effectiveness of adhesive luting agents to enamel and dentin. Dent Mater 2007; 23:71-80. [PMID: 16426673 DOI: 10.1016/j.dental.2005.12.002] [Citation(s) in RCA: 191] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Revised: 12/01/2005] [Accepted: 12/01/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVES The bonding effectiveness of five adhesive luting agents to enamel and dentin using different application procedures was determined using a micro-tensile bond strength protocol (microTBS). METHODS Enamel/dentin surfaces of human third molars were flattened using a high-speed diamond bur. Composite resin blocks (Paradigm, 3M ESPE) were luted using either Linkmax (LM; GC), Nexus 2 (NX; Kerr), Panavia F (PN; Kuraray), RelyX Unicem (UN; 3M ESPE) or Variolink II (VL; Ivoclar-Vivadent), strictly following manufacturers' instructions. For some luting agents, modified application procedures were also tested, resulting in four other experimental groups: Prompt L-Pop+RelyX Unicem (PLP+UN; 3M ESPE), Scotchbond Etchant+RelyX Unicem (SE+UN; 3M ESPE), Optibond Solo Plus Activator+Nexus 2 (ACT+NX; Kerr) and K-Etchant gel+Panavia-F (KE+P; Kuraray). The experimental groups were classified according to the adhesive approach in self-adhesive (UN), etch-and-rinse (ACT+NX, NX, KE+P, SE+UN and VL when bonded to enamel) and self-etch adhesive luting agents (LM, PLP+UN, PN and VL when bonded to dentin). The specimens were stored for 24h in distilled water at 37 degrees C prior to microTBS testing. The Kruskal-Wallis test was used to determine pairwise statistical differences (p<0.05) in microTBS between the experimental groups. RESULTS When bonded to enamel, ACT+NX (15 MPa) and UN (19.6 MPa) scored significantly lower than VL (49.3 MPa), LM (49.2 MPa), PN (35.4 MPa) and SE+UN (35.2 MPa), while PLP+UN (23.5 MPa) showed a significantly lower microTBS than VL (49.3 MPa) and LM (49.2 MPa). No significant differences were noticed between VL (49.3 MPa), LM (49.2 MPa), NX (37.9 MPa), KE+PN (38.8 MPa), PN (35.4 MPa) and SE+UN (35.2 MPa). Regarding the bonding effectiveness to dentin, all luting agents bonded equally effectively (UN: 15.9 MPa; LM: 15.4 MPa; PN: 17.5 MPa; NX: 22.3 MPa), except VL (1.1 MPa), SE+UN (5.9 MPa) and ACT+NX (13.2 MPa). VL revealed an exceptionally high number of pre-testing failures, most likely due to a combined effect of not having cured the adhesive separately and an insufficiently light-cured luting agent. SIGNIFICANCE Following a correct application procedure, the etch-and-rinse, self-etch and self-adhesive luting agents are equally effective in bonding to enamel and dentin. Several factors negatively influenced bond strength such as bonding RelyX Unicem to enamel without prior phosphoric acid etching; no separate light-curing of a light-polymerizable adhesive prior to cementation, use of a light-polymerizing adhesive converted into a dual-polymerizing adhesive, and use of a dual-cure luting agent with a low auto-polymerizable potential.
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Affiliation(s)
- K Hikita
- Leuven BIOMAT Research Cluster, Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, 3000 Leuven, Belgium
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Soares CJ, da Silva NR, Fonseca RB. Influence of the Feldspathic Ceramic Thickness and Shade on the Microhardness of Dual Resin Cement. Oper Dent 2006; 31:384-9. [PMID: 16802648 DOI: 10.2341/05-51] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
Polymerization of dual resin cements is significantly more affected by thickness of feldspathic ceramic restorations than by shade.
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Affiliation(s)
- Carlos José Soares
- Operative Dentistry Department, Dental School, Federal University of Uberlândia, MG, Brazil.
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Meng X, Yoshida K, Atsuta M. Hardness Development of Dual-cured Resin Cements through Different Thicknesses of Ceramics. Dent Mater J 2006; 25:132-7. [PMID: 16706308 DOI: 10.4012/dmj.25.132] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
This study investigated the Knoop hardness of a thin layer in three dual-cured resin cements (Linkmax HV, Nexus 2, and Variolink II HV) irradiated through or not through different thicknesses (1 through 5 mm) of a machinable ceramic. Hardness was recorded at a series of time intervals up to five days, starting from the end of a light irradiation period. Increase in hardness was more rapid over the first 0.5 hour; thereafter it continued at a low rate until maximum hardness was attained. Ceramic thickness had a significant influence on hardness in all dual-cured resin cements, especially when ceramic thickness was more than 4 mm. In addition, it was noted that the polymerization of Nexus 2 seemed to be more dependent on light exposure compared with the other two materials. Variolink II HV and Linkmax HV, on the other hand, seemed to indicate the potential of being compensated by chemical curing to some degree.
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Affiliation(s)
- Xiangfeng Meng
- Division of Fixed Prosthodontics and Oral Rehabilitation, Nagasaki University, Graduate School of Biomedical Sciences, Japan
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Nalcaci A, Kucukesmen C, Uludag B. Effect of high-powered LED polymerization on the shear bond strength of a light-polymerized resin luting agent to ceramic and dentin. J Prosthet Dent 2005; 94:140-5. [PMID: 16046968 DOI: 10.1016/j.prosdent.2005.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
STATEMENT OF PROBLEM A newly introduced high-powered light-emitting diode (LED) light-polymerization unit with various polymerization modes is purported to polymerize dental resins more quickly than standard units. However, there is insufficient information about the effects of this type of light source and its polymerization modes on resin luting agents (RLAs). PURPOSE This in vitro study evaluated the effects of different modes of a high-powered LED polymerization unit on the shear bond strength of a light-polymerized RLA to ceramic and dentin. MATERIAL AND METHODS Sixty ceramic cylinders (3 x 3 mm) were fabricated from a heat-pressed ceramic (IPS Empress 2). Specimen surfaces were abraded using 600-grit silicon carbide paper and airborne-particle abraded with 50-mum desiccant alumina particles, cleaned ultrasonically, etched using hydrofluoric acid, and treated with a silane coupling agent (Ceramic primer). Sixty noncarious, freshly extracted, permanent human molar teeth were embedded in autopolymerizing acrylic resin, and their dentin surfaces were wet-ground using a grinding and polishing machine fitted with 180-grit abrasive disks. The ground dentin surfaces were then etched with 37% phosphoric acid gel, and an adhesive agent (Single Bond) was applied. Ceramic specimens (n = 15) were bonded to dentin surfaces with a dual-initiated RLA (Rely-X ARC) and individually polymerized by 1 of 4 different modes, as follows: Halogen standard mode (Control) (600 mW/cm2 for 40 seconds); high-powered LED fast mode (1100 mW/cm2 for 10 seconds); high-powered LED pulse mode (1100 mW/cm2 for 10 seconds); and high-powered LED exponential mode (1100 mW/cm2 for 20 seconds). Cemented specimens were subjected to shear loading until fracture using a universal testing machine. A stereomicroscope (x25) was used to identify the mode of fracture. Bond strength (MPa) data were analyzed using 1-way analysis of variance and the Tukey HSD test (alpha = .05). RESULTS Specimens polymerized using halogen standard mode (23.9 +/- 1.3 MPa) and LED exponential mode (23.0 +/- 1.1 MPa) had significantly higher ( P < .001) mean shear bond strengths compared with both LED fast (15.1 +/- 1.3 MPa) and pulse (14.6 +/- 1.3 MPa) modes. The Tukey HSD tests showed no significant differences in shear bond strength between specimens polymerized using high-powered LED exponential mode and halogen standard mode. Most failures were adhesive failures at the dentin-RLA interface or the RLA-ceramic interface in specimens polymerized using high-powered LED fast or pulse modes. CONCLUSION Within the limitations of this study, the shear bond strength of an RLA to ceramic and dentin was found to be similar when polymerized using halogen light in standard mode and high-powered LED light in exponential mode, whereas shear bond strength was significantly lower when polymerized using LED in fast or pulse mode.
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Affiliation(s)
- Adil Nalcaci
- Faculty of Dentistry, Ankara University, Ankara, Turkey.
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Fonseca RG, Cruz CADS, Adabo GL. The influence of chemical activation on hardness of dual-curing resin cements. Braz Oral Res 2004; 18:228-32. [PMID: 15619876 DOI: 10.1590/s1806-83242004000300009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
During the cementation of metallic restorations, the polymerization of dual-curing resin cements depends exclusively on chemical activation. This study evaluated the influence of chemical activation compared with dual-curing (chemical and light activation), on the hardness of four dual-curing resin cements. In a darkened environment, equal weight proportions of base and catalyst pastes of the cements Scotchbond Resin Cement, Variolink II, Enforce and Panavia F were mixed and inserted into moulds with cavities of 4 mm in diameter and 2 mm in height. Subsequently, the cements were: 1) not exposed to light (chemical activation = self-cured groups) or 2) photoactivated (dual-curing = dual-cured groups). The Vickers hardness number was measured at 1 hour, 24 hours and 7 days after the start time of cements' spatulation. For all the cements, the hardness values of self-cured groups were lower than those of the respective dual-cured groups at 1 hour and 24 hours. At 7 days, this behavior continued for Variolink II and Panavia F, whilst for Scotchbond Resin Cement and Enforce there was no statistical difference between the two activation modes. All cements showed a significant increase in their hardness values from 1 hour to 7 days for both activation modes. Of the self-cured groups, Scotchbond Resin Cement and Variolink II presented the highest and the lowest hardness values, respectively, for all three times tested. Within the limitations of this study, up to the time of 24 h, chemical activation alone was unable to promote similar hardness as to that obtained with dual-curing.
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Affiliation(s)
- Renata Garcia Fonseca
- Department of Dental Materials and Prosthodontics, School of Dentistry of Araraquara, São Paulo State University
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Ozyesil AG, Usumez A, Gunduz B. The efficiency of different light sources to polymerize composite beneath a simulated ceramic restoration. J Prosthet Dent 2004; 91:151-7. [PMID: 14970761 DOI: 10.1016/j.prosdent.2003.11.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
STATEMENT OF PROBLEM Inadequate polymerization diminishes the physical properties of composite and compromises material strength. Newly developed light-polymerizing units (plasma arc and high intensity halogen) operate at relatively high intensity and are purported to provide optimum properties to composites in a shorter time. PURPOSE The aim of this in vitro study was to examine the polymerization efficacy of 3 different polymerization units through a simulated ceramic restoration by determining degree of monomer conversion of a composite luting Material. MATERIAL AND METHODS A conventional halogen light, a plasma arc light, and a high-intensity halogen light were used to polymerize a composite (Variolink II) with or without catalyst. A pressable ceramic block (5 mm in diameter, 2 mm in height) was used as an interface between the polymerizing light tip and composite. The composite/veneer combination was exposed to 2 different polymerization time protocols for each polymerization unit: (1) 20 or 40 seconds for conventional halogen light, (2) 3 or 6 seconds for plasma arc light, and (3) 10 or 20 seconds (under ramp mode) for the high-intensity halogen light. Using different light units, 120 composite specimens were evaluated (n = 5). Fourier transformation infrared spectroscopy was used to determine the level of light polymerization of the resin through the ceramic material with each of the light sources immediately after polymerization or after 24 hours. Degree of conversion was calculated as a percentage of experimentally polymerized versus maximally polymerized composite. The data were analyzed by 4-factor analysis of variance (alpha = .05). Independent t tests (alpha = .05) were used to detect differences between groups defined by the specific interacting variables. RESULTS Degree of conversion values varied with the light source (P < .05), polymerization type (P < .05), testing time (P < .01), and exposure to each light source (P < .01). Significant interactions were present between light source and polymerization type (P = .00), light source and testing time (P = .007), and polymerization type and testing time (P = .004). The degree of conversion values were significantly higher in dual-polymerized specimens after 24 hours (P < .01), but there were no significant differences in light-polymerized specimens after 24 hours. The degree of conversion values achieved were significantly lower (P < .05) when specimens were dual polymerized by conventional halogen light and measured immediately (31.59 +/- 7.76). The degree of conversion values achieved were significantly (P < .05) higher with dual polymerization by high-intensity halogen measured after 24 hours (65.06 +/- 8.14). There were no other significant differences among groups. CONCLUSION The highest degree of conversion values of composite were achieved with polymerization by high-intensity halogen. The plasma arc light achieved similar polymerization of composite through ceramic material in a markedly shorter period than conventional halogen light.
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van Dijken JWV. Resin-modified glass ionomer cement and self-cured resin composite luted ceramic inlays. A 5-year clinical evaluation. Dent Mater 2003; 19:670-4. [PMID: 12901993 DOI: 10.1016/s0109-5641(03)00011-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE This study evaluated IPS Empress ceramic inlays luted with two chemical-cured luting agents, a resin-modified glass ionomer cement (Fuji Plus (F)) and a resin composite (RC) (Panavia 21 (P)). METHODS Seventy-nine ceramic inlays were placed in Class II cavities in 29 patients. At least two inlays were placed in each patient to compare the luting techniques intra-individually. In each patient half of the inlays were luted with F and the other half with P. The inlays were evaluated clinically, according to modified USPHS criteria (van Dijken, 1986), at baseline, after 6 months, and yearly during 5 years. RESULTS At 5 years, 71 inlays were evaluated. Two small partial fractures were observed at 3 years (1P, 1F). One inlay showed recurrent root caries at 4 years (P). Four inlays, two in each group showed non-acceptable color match (2P, 2F). Small defects were observed in 4 inlays (2P, 2F). A slight ditching of the cement margins was observed in both luting groups but did not seem to increase during the second half of the evaluation. No significant difference in durability was observed between the two luting agents. SIGNIFICANCE IPS Empress inlays luted with the chemical-cured RC and the resin-modified glass ionomer cement functioned satisfactory during the 5 years follow-up.
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Affiliation(s)
- Jan W V van Dijken
- Department of Odontology, Dental School Umeå, Umeå University, Umea 901 87, Sweden.
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Meyer A, Cardoso LC, Araujo E, Baratieri LN. Ceramic Inlays and Onlays: Clinical Procedures for Predictable Results. J ESTHET RESTOR DENT 2003; 15:338-51; discussion 352. [PMID: 14982661 DOI: 10.1111/j.1708-8240.2003.tb00307.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
UNLABELLED The use of ceramics as restorative materials has increased substantially in the past two decades. This trend can be attributed to the greater interest of patients and dentists in this esthetic and long-lasting material, and to the ability to effectively bond metal-free ceramic restorations to tooth structure using acid-etch techniques and adhesive cements. The purpose of this article is to review the pertinent literature on ceramic systems, direct internal buildup materials, and adhesive cements. Current clinical procedures for the planning, preparation, impression, and bonding of ceramic inlays and onlays are also briefly reviewed. A representative clinical case is presented, illustrating the technique. CLINICAL SIGNIFICANCE When posterior teeth are weakened owing to the need for wide cavity preparations, the success of direct resin-based composites is compromised. In these clinical situations, ceramic inlays/onlays can be used to achieve esthetic, durable, and biologically compatible posterior restorations.
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Affiliation(s)
- Alfredo Meyer
- Department of Operative Dentistry, Federal University of Santa Catarina, Av. Rio Branco 405, Torre 1, Sala 204, Centro, Florianópolis, Santa Catarina 88015-200, Brazil.
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Dietschi D, Marret N, Krejci I. Comparative efficiency of plasma and halogen light sources on composite micro-hardness in different curing conditions. Dent Mater 2003; 19:493-500. [PMID: 12837397 DOI: 10.1016/s0109-5641(02)00095-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVES Recent developments have led to the introduction of high power curing lights, which are claimed to greatly reduce the total curing time. This study evaluated the effectiveness of a plasma-curing device (Apollo 95 E) and a halogen device (Heliolux DLX), in different curing conditions. METHOD Vicker's micro-hardness values were performed on 1 and 2 mm thick composite discs cured in a natural tooth mold by direct irradiation or indirect irradiation through composite material (2 or 4 mm) and dental tissues (1 mm enamel or 2 mm enamel-dentin). Measures were, respectively, performed after a 1, 3, 6 s (SC, step curing mode) or 18 s (3xSC) exposure to the plasma light, and a 5, 10, 20 or 40 s exposure to the halogen light. RESULTS With the PAC light used, a 3 s irradiation in the direct curing condition was necessary to reach hardness values similar to those obtained after a 40 s exposure to the halogen light. Using the indirect curing condition, hardness values reached after an 18 s exposure (3xSC mode) with the plasma light were either equivalent or inferior to those obtained with 40 s halogen irradiation. SIGNIFICANCE Direct polymerization with the plasma light used requires longer exposure times than those initially proposed by the manufacturer. The effectiveness of plasma generated light was lowered by composite or natural tissues, and therefore requires an important increase in the irradiation time when applied to indirect polymerization. The practical advantage of this polymerization method is less than expected, when compared to traditional halogen curing.
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Affiliation(s)
- D Dietschi
- Division de Cariologie, d'Endodontie et de Pédodontie, Section de Médecine Dentaire, Faculté de Médecine, Université de Genève, 19 Rue Barthélémy Menn, 1205 Geneva, Switzerland.
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Abstract
Current ceramic materials offer preferred optical properties for highly esthetic restorations. The inherent brittleness of some ceramic materials, specific treatment modalities, and certain clinical situations require resin bonding of the completed ceramic restoration to the supporting tooth structures for long-term clinical success. This article presents a literature review on the resin bond to dental ceramics. A PubMed database search was conducted for in vitro studies pertaining to the resin bond to ceramic materials. The search was limited to peer-reviewed articles published in English between 1966 and 2001. Although the resin bond to silica-based ceramics is well researched and documented, few in vitro studies on the resin bond to high-strength ceramic materials were identified. Available data suggest that resin bonding to these materials is less predictable and requires substantially different bonding methods than to silica-based ceramics. Further in vitro studies, as well as controlled clinical trials, are needed.
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Affiliation(s)
- Markus B Blatz
- School of Dentistry, Department of Prosthodontics, Louisiana State University Health Sciences Center, New Orleans 70119, USA.
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49
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Abstract
OBJECTIVES Porcelain veneers are steadily increasing in popularity among today's dental practitioners for conservative restoration of unaesthetic anterior teeth. As with any new procedure, in vitro and in vivo investigations are required to assess the ultimate clinical efficacy of these restorations. The current literature was therefore reviewed in search for the most important parameters determining the long-term success of porcelain veneers. DATA SOURCES Laboratory studies focusing on parameters in prediction of the clinical efficacy of porcelain veneers such as the tooth preparation for porcelain veneers, the selection and type of the adhesive system, the quality of marginal adaptation, the resistance against microleakage, the periodontal response, and the aesthetic characteristics of the restorations have been reviewed. The clinical relevance of these parameters was then determined by reviewing the results of short and medium to long-term in vivo studies involving porcelain veneers performed during the last 10 years. CONCLUSIONS The adhesive porcelain veneer complex has been proven to be a very strong complex in vitro and in vivo. An optimal bonded restoration was achieved especially if the preparation was located completely in enamel, if correct adhesive treatment procedures were carried out and if a suitable luting composite was selected. The maintenance of aesthetics of porcelain veneers in the medium to long term was excellent, patient satisfaction was high and porcelain veneers had no adverse effects on gingival health inpatients with an optimal oral hygiene. Major shortcomings of the porcelain veneer system were described as a relatively large marginal discrepancy, and an insufficient wear resistance of the luting composite. Although these shortcomings had no direct impact on the clinical success of porcelain veneers in the medium term, their influence on the overall clinical performance in the long term is still unknown and therefore needs further study.
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Affiliation(s)
- M Peumans
- Department of Operative Dentistry and Dental Materials, School of Dentistry, Oral Pathology and Maxillo-Facial Surgery, Catholic University of Leuven, Belgium
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50
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Abstract
OBJECTIVES To quantify the width of the cement interface between ceramic inlays generated by the CEREC-2 CAD-CAM system and the tooth, and to determine the effect of cement viscosity on the interface width. METHODS Standardised MOD cavities were cut in 15 human premolar teeth using a custom paralleling device. A ceramic inlay was made with a CEREC-2 CAD-CAM machine for each tooth. The inlays were cemented using one of three resin-based composite systems of varying viscosity; a hybrid microfilled posterior composite, a compomer restorative and a dual-cure luting composite. The teeth were subsequently sectioned and measurements were taken at 21 key points with the aid of an image-analysis light microscopy system. RESULTS Statistical significance tests were applied to examine for difference in interface dimensions at specific points within each of the cement-groups and amongst groups. The interface space at the occlusal walls has a distinct wedge shape, being narrower at the external interface (50 microns, SD 15) than internally (211 microns, SD 38). There is no statistically significant difference in the interface dimensions of the gingival floor between the boxes that lie above and below the CEJ. There is no statistically significant difference in the width of the interface at any given point between the three cement groups. SIGNIFICANCE There is a significant improvement in the fit of CEREC-2 restorations when compared with the original CEREC system. Cements of varying viscosity (within the measured range) may be used for cementation of these inlays, without adversely affecting the width of the interface. Caution must be exercised with light-activated composite cements to ensure adequate transmission of light through the ceramic and the underlying composite cement.
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Affiliation(s)
- N Martin
- Department of Clinical Dental Sciences, University of Liverpool, L69 3BX, Liverpool, UK.
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