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Karkehabadi H, Rahmati A, Abbaspourrokni H, Farmany A, Najafi R, Behroozi R, Rezaei-Soufi L, Abbasi R. Effect of magnesium oxide nanoparticles and LED irradiation on the viability and differentiation of human stem cells of the apical papilla. Biotechnol Lett 2024; 46:263-278. [PMID: 38326543 DOI: 10.1007/s10529-024-03471-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 12/15/2023] [Accepted: 01/26/2024] [Indexed: 02/09/2024]
Abstract
PURPOSE Currently, regenerative endodontic treatments are gaining more and more attention, and stem cells play a significant role in these treatments. In order to enhance stem cell proliferation and differentiation, a variety of methods and materials have been used. The purpose of this study was to determine the effects of magnesium oxide nanoparticles and LED irradiation on the survival and differentiation of human stem cells from apical papilla. METHODS The MTT test was used to measure the cell survival of SCAPs that had been exposed to different concentrations of magnesium oxide nanoparticles after 24 and 48 h, and the concentration with the highest cell survival rate was picked for further studies. The cells were classified into four distinct groups based on their treatment: (1) control, which received no exposure, (2) exposure to magnesium oxide nanoparticles, (3) exposure to light emitting diode (LED) irradiation (635 nm, 200 mW/cm2) for 30 s, (4) exposure simultaneously with magnesium oxide nanoparticles and LED irradiation. A green approach was employed to synthesize magnesium oxide nanoparticles. Quantitative real time PCR was used to measure the gene expression of osteo/odontogenic markers such as BSP, DSPP, ALP and DMP1 in all four groups after treatment, and Alizarin red S staining (ARS) was used to determine the osteogenic differentiation of SCAPs by demonstrating the Matrix mineralization. RESULTS The highest viability of SCAPs was observed after 24 h in concentration 1 and 10 µg/mL and after 48 h in concentration 1 µg/mL, which were not significantly different from the control group. In both times, the survival of SCAPs decreased with increasing concentration of magnesium oxide nanoparticles (MgONPs). According to the results of Real-time PCR, after 24 and 48 h, the highest differentiation of BSP, DMP1, ALP and DSPP genes was observed in the LED + MgONPs group, followed by MgONPs and then LED, and in all 3 experimental groups, it was significantly higher than control group (P < 0.05). Also, after 24 and 48 h, the density of ARS increased in all groups compared to the control group, and the highest density was observed in the MgONPs + LED and MgONPs groups. CONCLUSION This research concluded that exposure to SCAPs, MgONPs, and LED irradiation has a significant effect on enhancing gene expression of odontogenic/osteogenic markers and increasing matrix mineralization.
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Affiliation(s)
- Hamed Karkehabadi
- Department of Endodontics, Dental Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Afsaneh Rahmati
- Department of Endodontics, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Hadiseh Abbaspourrokni
- Department of Endodontics, Faculty of Dentistry, Mazandaran University of Medical Sciences, Sari, Iran
| | - Abbas Farmany
- Dental Research Center, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Rezvan Najafi
- Department of Medical Molecular and Genetics, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | | | - Loghman Rezaei-Soufi
- Department of Operative Dentistry, Dental Research Center, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Roshanak Abbasi
- Department of Endodontics, Dental Research Center, Hamadan University of Medical Sciences, Hamadan, Iran.
- Department of Endodontics, School of Dentistry, Lorestan University of Medical Sciences, Khorramabad, Iran.
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Rahmati A, Abbasi R, Najafi R, Asnaashari M, Behroozi R, Rezaei-Soufi L, Karkehabadi H. Effect of Low-Level Diode Laser and Red Light-Emitting Diode on Survival and Osteogenic/Odontogenic Differentiation of Human Dental Pulp Stem Cells. Photobiomodul Photomed Laser Surg 2024; 42:306-313. [PMID: 38546858 DOI: 10.1089/photob.2023.0127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
Background: This investigation set out to compare the impacts of low-level diode laser (LLDL) and red light-emitting diode (LED) on the survival of human dental pulp stem cells (hDPSCs) and osteogenic/odontogenic differentiation. Methods and materials: In this ex vivo experimental study, the experimental groups underwent the irradiation of LLDL (4 J/cm2 energy density) and red LED in the osteogenic medium. Survival of hDPSCs was assessed after 24 and 48 h (n = 9) using the methyl thiazolyl tetrazolium (MTT) assay. The assessment of osteogenic/odontogenic differentiation was conducted using alizarin red staining (ARS; three repetitions). The investigation of osteogenic and odontogenic gene expression was performed at two time points, specifically 24 and 48 h (n = 12). This analysis was performed utilizing real-time reverse-transcription polymerase chain reaction (RT-PCR). The groups were compared at each time point using SPSS version 24. To analyze the data, the Mann-Whitney U test, analysis of variance, Tukey's test, and t-test were utilized. Results: The MTT assay showed that LLDL significantly decreased the survival of hDPSCs after 48 h, compared with other groups (p < 0.05). The qualitative results of ARS revealed that LLDL and red LED increased the osteogenic differentiation of hDPSCs. LLDL and red LED both upregulated the expression of osteogenic/odontogenic genes, including bone sialoprotein (BSP), alkaline phosphatase (ALP), dentin matrix protein 1 (DMP1), and dentin sialophosphoprotein (DSPP), in hDPSCs. The LLDL group exhibited a higher level of gene upregulation (p < 0.0001). Conclusions: The cell survival of hDPSCs was reduced, despite an increase in osteogenic/odontogenic activity. Clinical relevance: Introduction of noninvasive methods in regenerative endodontic treatments.
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Affiliation(s)
- Afsaneh Rahmati
- Department of Endodontics, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Roshanak Abbasi
- Department of Endodontics, School of Dentistry, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Rezvan Najafi
- Department of Medical Molecular & Genetics, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Mohammad Asnaashari
- Laser Application in Medical Sciences Research Center, Department of Endodontics, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Loghman Rezaei-Soufi
- Department of Operative Dentistry, Dental Research Center, School of Dentistry, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Hamed Karkehabadi
- Department of Endodontics, Dental Research Center, Hamadan University of Medical Sciences, Hamadan, Iran
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Karkehabadi H, Rahmati A, Abbasi R, Farmany A, Najafi R, Behroozi R, Rezaei-Soufi L, Abbaspourrokni H. Effect of copper oxide nanoparticles and light-emitting diode irradiation on the cell viability and osteogenic/odontogenic differentiation of human stem cells from the apical papilla. BMC Oral Health 2023; 23:249. [PMID: 37118787 PMCID: PMC10148393 DOI: 10.1186/s12903-023-02916-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 03/28/2023] [Indexed: 04/30/2023] Open
Abstract
OBJECTIVES This experimental study aimed to assess the effect of copper oxide nanoparticles (CuONPs) and light-emitting diode (LED) irradiation on the cell viability and osteogenic/odontogenic differentiation of human SCAPs. METHODS After the culture of SCAPs, the effects of different concentrations of CuONPs on cell viability were evaluated by the methyl thiazolyl tetrazolium (MTT) assay after 24 and 48 h, and the optimal concentration was determined (n = 12). SCAPs were then divided into four groups based on the type of treatment: (I) no-treatment control group, (II) exposure to CuONPs, (III) LED irradiation (635 nm, 200 mW/cm2) for 30 s, and (IV) exposure to CuONPs combined with LED irradiation. CuONPs were synthesized by a green technique, which was based on reduction and simultaneous stability of copper ions by using the pomegranate peel extract. After treatments, the expression of osteogenic/odontogenic markers including dentin sialophosphoprotein (DSPP), bone sialoprotein (BSP), alkaline phosphatase (ALP), and dentin matrix acidic phosphoprotein 1 (DMP1) was evaluated in all four groups using quantitative real-time polymerase chain reaction (PCR) (n = 16). Also, osteogenic differentiation of SCAPs was evaluated qualitatively by alizarin red staining (ARS) to assess the matrix mineralization (n = 4). SPSS version 18 was used for data evaluation. The Kruskal-Wallis and Mann-Whitney tests were used to compare the groups. RESULTS Exposure to 1 µg/mL CuONPs resulted in maximum viability of SCAPs. Concentrations of CuONPs over 10 µg/mL significantly decreased the viability of SCAPs. Real-time PCR showed that the expression of DMP1, BSP, ALP, and DSPP in CuONPs + LED and LED groups was significantly higher than that in CuONPs and control groups at both 24 and 48 h (P < 0.05). The density of ARS increased in all experimental groups after 24 h, and in CuONPs + LED and CuONPs groups after 48 h, compared to the control group. CONCLUSION Addition of CuONPs and LED irradiation of SCAPs in the culture medium significantly enhanced their osteogenic/odontogenic differentiation.
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Affiliation(s)
- Hamed Karkehabadi
- Department of Endodontics, Dental Research Center, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Afsaneh Rahmati
- Department of Endodontics, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Roshanak Abbasi
- Department of Endodontics, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Abbas Farmany
- Dental Research Center, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Rezvan Najafi
- Department of Medical Molecular & Genetics, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | | | - Loghman Rezaei-Soufi
- Department of Operative Dentistry, Dental Research Center, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Hadiseh Abbaspourrokni
- Department of Endodontics, Faculty of Dentistry, Mazandaran University of Medical Sciences, Sari, Iran.
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Rahmati A, Abbasi R, Najafi R, Rezaei-soufi L, Karkehabadi H. Effect of diode low level laser and red light emitting diode irradiation on cell proliferation and osteogenic/odontogenic differentiation of stem cells from the apical papilla. BMC Oral Health 2022; 22:543. [PMID: 36434589 PMCID: PMC9701043 DOI: 10.1186/s12903-022-02574-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 11/08/2022] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND This experimental study aimed to assess the effect of irradiation of red light-emitting diode (LED) and Diode low-level laser (LLL) on osteogenic/odontogenic differentiation of stem cells from the apical papilla (SCAPs). MATERIALS AND METHODS SCAPs were isolated from the human tooth root. The experimental groups were subjected to 4 J/cm2 diode low level laser and red LED irradiation in osteogenic medium. The control group did not receive any irradiation. Cell viability/proliferation of SCAPs was assessed by the methyl thiazolyl tetrazolium (MTT) assay on days 1 and 2 (n = 9). Osteogenic differentiation was evaluated by alizarin red staining (ARS) (n = 3), and expression of osteogenic genes by real-time polymerase chain reaction (RT-PCR) (n = 12) on days 1 and 2. SPSS version 18 was used for data evaluation. The Kruskal-Wallis and Mann-Whitney tests were used to compare the groups at each time point. RESULTS The MTT assay showed no significant difference in cell viability/proliferation of SCAPs in the low level laser, red LED, and control groups at 24 or 48 h (P < 0.001). The ARS assessment showed that low level laser and red LED irradiation enhanced osteogenic differentiation of SCAPs. low level laser and red LED irradiation both induced over-expression of osteogenic/dentinogenic genes including alkaline phosphatase (ALP), dentin sialophosphoprotein (DSPP), dentin matrix protein 1 (DMP-1), and bone sialoprotein (BSP) in SCAPs. Up-regulation of genes was significantly greater in low level laser irradiation group than red LED group (P < 0.001). CONCLUSION Diode low level laser irradiation with 4 J/cm2 energy density and red LED irradiation enhanced osteogenic differentiation of SCAPs without adversely affecting cell viability.
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Affiliation(s)
- Afsaneh Rahmati
- grid.411950.80000 0004 0611 9280Endodontic Department, School of Dentistry, Hamadan University of Medical Science, Hamadan, Iran
| | - Roshanak Abbasi
- grid.411950.80000 0004 0611 9280Endodontic Department, School of Dentistry, Hamadan University of Medical Science, Hamadan, Iran ,grid.411950.80000 0004 0611 9280Department of Medical Molecular & Genetics, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Rezvan Najafi
- grid.411950.80000 0004 0611 9280Department of Medical Molecular & Genetics, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran ,grid.411950.80000 0004 0611 9280Dental Research Center, Department of Operative Dentistry, School of dentistry, Hamadan University of Medical Science, Hamadan, Iran
| | - Loghman Rezaei-soufi
- grid.411950.80000 0004 0611 9280Dental Research Center, Department of Operative Dentistry, School of dentistry, Hamadan University of Medical Science, Hamadan, Iran
| | - Hamed Karkehabadi
- grid.411950.80000 0004 0611 9280Endodontic Department, School of Dentistry, Hamadan University of Medical Science, Hamadan, Iran
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David-Pérez M, Ramírez-Suárez JP, Latorre-Correa F, Agudelo-Suárez AA. Degree of conversion of resin-cements (light-cured/dual-cured) under different thicknesses of vitreous ceramics: systematic review. J Prosthodont Res 2022; 66:385-394. [PMID: 34853236 DOI: 10.2186/jpr.jpr_d_20_00090] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
PURPOSE This systematic review synthesized and analyzed the scientific evidence on the degree of conversion (DC) obtained by Fourier-transform infrared spectroscopy (FTIR) of light-cured and dual-cured resinous cements, photopolymerized under different thicknesses of vitreous ceramics. STUDY SELECTION The study protocol of this systematic review was registered at the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42017069319). A comprehensive search (PubMed/MEDLINE, Scopus, EMBASE, and LILACS) was performed for papers including an in vitro design and indexed from January 2007 to December 2020 according to the study purposes. A quality appraisal (specific instrument) and descriptive analysis of the articles that met the inclusion criteria were conducted. RESULTS Nine included studies were analyzed. Two of them used feldspathic ceramics, six used lithium disilicate, and one used both (comparing different types and opacities of ceramics). Three studies found a higher DC in dual cements, while one did not find any significant differences, and five studies found a higher DC in light-cured resin cements. Light-cured cements showed a better DC in relation to dual-cured cements in vitreous ceramic restorations with thicknesses up to 2 mm. CONCLUSION According to the findings, the use of good photoactivation is the most relevant variable to achieve an adequate DC in light-cured and dual-cured resin cements. The use of vitreous ceramic restorations with a thickness of less than 2 mm (light-curing cements) shows a better DC. Standardized in vitro studies are required to generate accurate scientific evidence.
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Andrade ACM, Trennepohl AA, Moecke SE, Borges AB, Torres CRG. Viscosity modulation of resin composites versus hand application on internal adaptation of restorations. Clin Oral Investig 2022; 26:4847-4856. [PMID: 35314890 DOI: 10.1007/s00784-022-04452-7] [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: 10/21/2021] [Accepted: 03/12/2022] [Indexed: 11/24/2022]
Abstract
OBJECTIVE To compare the effect of the injection of viscosity modulated resin composites versus hand application without modulation, on the internal adaptation of different material to the gingival wall of class II preparations. MATERIALS AND METHODS Class II cavities were created on mesial and distal surfaces of 60 extracted human molars, resulting on 120 tooth preparations (n = 120). The preparations were restored with four resin composites: VIS-VisCalor (Voco); GRA-GrandioSO (Voco); FIL-Filtek One Bulk Fill (3 M/ESPE); and SON-SonicFill (Kerr). Each composite was applied by two different techniques: by hand (H) or assisted (A). For the hand technique, the material was placed into the preparation using a spatula. For the assisted technique, the resin composite was heated up to 65 °C (for VIS, GRA, and FIL) or sonicated (for SON) and injected into the preparation. After the restorative procedures, the teeth were completely demineralized to allow the restoration removal. The total area of the gingival wall and the area occupied by interfacial defects of adaptation (TDA) were measured by optical microscopy and digital software. The percentage of the area occupied by the defects (%TDA) in relation to the total area was calculated. The data were analyzed by two-way ANOVA and Tukey tests. RESULTS Significant differences were observed for the application technique (p = 0.0403) and for the materials (p = 0.0184), as well for the interaction between them (p = 0.0452). The mean (standard deviation) of %TDA and results of Tukey test for the interaction were as follows: SON/H - 1.04(0.75)a; VIS/A - 2.01(0.92)a; VIS/H - 3.62(0.99)b; GRA/A - 6.23(3.32)b; FIL/H - 7.45(3.31)bc; GRA/H - 9.21(4.53)c; SON/A - 11.26(4.04)a; FIL/A - 17.89(5.08)d. CONCLUSION The injection of heated resin composites improves the adaptation to the walls in relation to the hand technique for VisCalor and GrandioSO but worsens for Filtek One. Sonic vibration increases the number of interfacial defects for SonicFill. CLINICAL RELEVANCE The physical modulation of the resin composite viscosity can improve or worsen the material adaptation to the walls of class II restoration. It had a positive impact for VisCalor and GrandioSO but a negative for Filtek One and SonicFill.
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Affiliation(s)
- Adrielle Caroline Moreira Andrade
- Department of Restorative Dentistry, Institute of Science and Technology, Sao Paulo State University - UNESP, Av. Eng. Francisco Jose Longo, 777, Sao Jose dos Campos, São Paulo, Zip code: 12245-000, Brazil
| | - Amanda Acioli Trennepohl
- Department of Restorative Dentistry, Institute of Science and Technology, Sao Paulo State University - UNESP, Av. Eng. Francisco Jose Longo, 777, Sao Jose dos Campos, São Paulo, Zip code: 12245-000, Brazil
| | - Sabrina Elise Moecke
- Department of Restorative Dentistry, Institute of Science and Technology, Sao Paulo State University - UNESP, Av. Eng. Francisco Jose Longo, 777, Sao Jose dos Campos, São Paulo, Zip code: 12245-000, Brazil
| | - Alessandra Bühler Borges
- Department of Restorative Dentistry, Institute of Science and Technology, Sao Paulo State University - UNESP, Av. Eng. Francisco Jose Longo, 777, Sao Jose dos Campos, São Paulo, Zip code: 12245-000, Brazil
| | - Carlos Rocha Gomes Torres
- Department of Restorative Dentistry, Institute of Science and Technology, Sao Paulo State University - UNESP, Av. Eng. Francisco Jose Longo, 777, Sao Jose dos Campos, São Paulo, Zip code: 12245-000, Brazil.
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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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Bayarsaikhan E, Gu H, Hwangbo NK, Lim JH, Shim JS, Lee KW, Kim JE. Influence of different postcuring parameters on mechanical properties and biocompatibility of 3D printed crown and bridge resin for temporary restorations. J Mech Behav Biomed Mater 2022; 128:105127. [PMID: 35182913 DOI: 10.1016/j.jmbbm.2022.105127] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/08/2022] [Accepted: 02/08/2022] [Indexed: 11/25/2022]
Abstract
This study analyzed the flexural properties, Vickers hardness, degree of conversion (DC), and cell viability of 3D printed crown and bridge resin postcured using various types of postcuring equipment (PCE). 3D printed specimens were postcured for various times using different types of 3D printing PCE [for 5, 15, and 30 min using LC 3D Print Box (LC), Form Cure (FC), Cure M (CM), and Veltz 3D (VE) devices] and the VALO handheld light-curing (VA) device for 20, 40, and 60 s. Neither the flexural strength (132.27-145.79 MPa) nor the flexural modulus (1.52-1.83 GPa) differed significantly when postcuring for 30 min using the LC, FC, CM, or VE device, or for 20, 40, or 60 s of postcuring using the VA device (p > 0.05). The Vickers hardness was highest after 30 min of postcuring for all groups, and varied significantly with the postcuring time in the LC (p < 0.001) and CM (p < 0.001) groups. DC was significantly higher for the 5-min CM group (84.97 ± 4.02%) than for the GS, 30-min FC, 5-min VE, and 20-s VA groups. Cell viability of the postcured resin specimens was 56.46-92.29%, and varied significantly in the CM and VE groups according to the postcuring time (p < 0.05). Confocal laser scanning microscopy observations showed well-developed cell morphology and numerous cell-cell contacts in all groups except the GS group. This study found that the use of different types of PCE did not significantly affect the flexural properties of 3D printed crown and bridge resin, whereas there were significant variations in DC, Vickers hardness, and cell viability.
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Affiliation(s)
- Enkhjargal Bayarsaikhan
- Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Hanna Gu
- Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Na-Kyung Hwangbo
- Department of Orofacial and Oral Medicine, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Jung-Hwa Lim
- Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - June-Sung Shim
- Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Keun-Woo Lee
- Dental Hospital, VHS Medical Center, Seoul, Republic of Korea
| | - Jong-Eun Kim
- Department of Prosthodontics, College of Dentistry, Yonsei University, Seoul, Republic of Korea.
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Rocha Gomes Torres C, Caroline Moreira Andrade A, Valente Pinho Mafetano AP, Stabile de Abreu F, de Souza Andrade D, Cintra Mailart M, Aun de Barros Lima Rocha Campello de Souza ML, Guimarães Alarça Nunes L, Ariel Rodrigues de Araújo C, Di Nicoló R, Bühler Borges A. Computer-aided design and computer-aided manufacturing indirect versus direct composite restorations: A randomized clinical trial. J ESTHET RESTOR DENT 2021; 34:776-788. [PMID: 34590418 DOI: 10.1111/jerd.12820] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/31/2021] [Accepted: 09/09/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE This study compared the clinical performance of large indirect restorations (IRs) versus direct restorations (DRs) in posterior teeth. METHODS Thirty subjects received two class II restorations (n = 60), one fabricated from a precured composite block (Grandio Blocs, VOCO) for the indirect technique (IT) and the other with light-cured composite (GrandioSO, VOCO) for the direct technique (DT). For IT, the restoration was created using the computer-aided design and computer-aided manufacturer (CAD/CAM) system. For DT, the material was applied light-cured by using a layering technique. All restorations were evaluated by using the World Dental Federation criteria. RESULTS Twenty-three subjects attended the 2-year recall, and 46 restorations were evaluated. No significant differences were detected between the techniques for most parameters analyzed (p > 0.05). For "color match" at 7 days and 6 months, better results were observed for the DT. In relation to the overall scores, all restorations were esthetically acceptable after 2 years, while 93.3% of DT and 90% of IT showed acceptable function. For biological scores, 96.67% of DRs and 100% of IRs was acceptable after 24 months. Considering all properties, the success rates were 93.3% for DRs and 90% for IRs. CONCLUSIONS After 2 years, both restorations presented similar and good clinical behavior for all the properties analyzed. CLINICAL SIGNIFICANCE Light-cured direct posterior composite restorations may perform similarly to indirect composite restorations made with precured CAD/CAM composite blocks up to 2 years.
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Affiliation(s)
- Carlos Rocha Gomes Torres
- Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University-UNESP, São Paulo, Brazil
| | | | | | - Fabrícia Stabile de Abreu
- Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University-UNESP, São Paulo, Brazil
| | - Danilo de Souza Andrade
- Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University-UNESP, São Paulo, Brazil
| | - Mariane Cintra Mailart
- Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University-UNESP, São Paulo, Brazil
| | | | - Lilian Guimarães Alarça Nunes
- Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University-UNESP, São Paulo, Brazil
| | | | - Rebeca Di Nicoló
- Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University-UNESP, São Paulo, Brazil
| | - Alessandra Bühler Borges
- Department of Restorative Dentistry, Institute of Science and Technology, São Paulo State University-UNESP, São Paulo, Brazil
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Palialol AR, Martins CP, Dressano D, Aguiar FHB, Gonçalves LS, Marchi GM, Pfeifer CS, Lima AF. Improvement on properties of experimental resin cements containing an iodonium salt cured under challenging polymerization conditions. Dent Mater 2021; 37:1569-1575. [PMID: 34407920 DOI: 10.1016/j.dental.2021.08.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 08/04/2021] [Indexed: 11/19/2022]
Abstract
OBJECTIVE The use of resin cements in clinical practice entails photopolymerization through prosthetic devices, which precludes light penetration. The objective of this study was to modify experimental resin cements (ERCs) with diphenyliodonium hexafluorophosphate (DPI) in an attempt to improve chemical and mechanical properties of materials cured with reduced irradiance and final radiant exposure. METHODS A co-monomer base containing a 1:1 mass ratio of 2.2-bis[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]propane (bis-GMA) and triethyleneglycol dimethacrylate (TEGDMA) was prepared, with 1mol% of camphorquinone and 2mol% of ethyl 4-(dimethylamino)benzoate as initiator system. The resin was divided into 4 fractions according to the DPI concentrations (0, 0.5, 1 and 2mol%). The challenging polymerization condition was simulated performing the light activation (12, 23 and 46s) through a ceramic block (3mm thick). The irradiance was assessed with a calibrated spectrometer (1320mW/cm2), resulting in three levels of radiant exposure (0.58, 1.1 and 2.2J/cm2). The polymerization kinetics was evaluated in real-time using a spectrometer (Near-IR). Water sorption and solubility was analyzed and the cohesive strength of resins obtained through the microtensile test. Polymerization stress was assessed by Bioman method. RESULTS Resins containing DPI had higher degree of conversion and rate of polymerization than the control (without DPI). The use of DPI reduced water sorption and solubility, and led to higher cohesive strength compared to resins without the iodonium salt. However, the stress of polymerization was higher for experimental resins with DPI. SIGNIFICANCE Even under remarkably reduced irradiance, cements containing a ternary initiating system with an iodonium salt can present an optimal degree of conversion and chemical/mechanical properties.
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Affiliation(s)
- Alan R Palialol
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 Mail Box 52, Piracicaba, SP 13414-903, Brazil.
| | - Caetano P Martins
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 Mail Box 52, Piracicaba, SP 13414-903, Brazil.
| | - Diogo Dressano
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 Mail Box 52, Piracicaba, SP 13414-903, Brazil.
| | - Flavio H B Aguiar
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 Mail Box 52, Piracicaba, SP 13414-903, Brazil.
| | - Luciano S Gonçalves
- Department of Restorative Dentistry, School of Dentistry, Federal University of Santa Maria, Av. Roraima, 1000 - Camobi, Santa Maria, RS 97105-900, Brazil.
| | - Giselle M Marchi
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, Av. Limeira, 901 Mail Box 52, Piracicaba, SP 13414-903, Brazil.
| | - Carmem S Pfeifer
- Biomaterials and Biomechanics, Department of Restorative Dentistry, Oregon Health & Science University, Portland, OR 97239, USA.
| | - Adriano F Lima
- Dental Research Division, Paulista University, Rua Doutor Bacelar, 1212, 04026-002 SP, Brazil.
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11
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Balhaddad AA, Marghalani AA, Raderman MA, Miginsky E, Massey W, Strassler H, Anne Melo M. Hands-on training based on quantifying radiant exposure improves how dental students cure composites: Skill retention at 2-year follow-up. EUROPEAN JOURNAL OF DENTAL EDUCATION : OFFICIAL JOURNAL OF THE ASSOCIATION FOR DENTAL EDUCATION IN EUROPE 2021; 25:582-591. [PMID: 33220151 DOI: 10.1111/eje.12635] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 11/18/2020] [Accepted: 11/18/2020] [Indexed: 05/27/2023]
Abstract
INTRODUCTION The durability and longevity of composite restoration are much dependent on the accurate delivery of the energy required to polymerise the material. This study aimed to investigate the extent to which undergraduate dental students acquire and retain light-curing skills following hands-on training. MATERIALS AND METHODS Hands-on training comprises faculty tutoring for critical aspects of the light-curing procedure, such as distance and angulation of the light-curing tip. Assessments of the students' ability to deliver a specified radiant exposure to class III and I simulated RBCs using a dental simulator (MARC-PS® ) at three different time points after the training. Data were analysed using repeated measure ANOVA. RESULTS Immediately after the training, students' performance on curing was improved (p < .05). Overall, the radiant exposure increased after training, but the students lost some of the benefits with time. For curing in the anterior section (anterior sensor-class III), the mean radiant exposure values increased by approximately 20% after the training. After 2 years, the values were 15% greater than baseline values. For curing in the posterior section (posterior sensor-class I), the mean radiant exposure values increased by approximately 150% after the training. A significant decrease (p < .05) was observed; however, the radiant exposure values were still 82% greater than the baseline after 2 years. CONCLUSION A hands-on training dedicated to light-curing procedures facilitated acquisition and retention up to a 2-year follow-up of skill on how light cure composite inside the mouth. The training was more relevant for curing in posterior areas, where orientation can significantly impact light-curing. A hands-on training where the radiant exposure can be measure gave objective measurement metrics to guide the curing performance. This approach is an effective means of teaching practical skills to dental students.
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Affiliation(s)
- Abdulrahman A Balhaddad
- Dental Biomedical Science PhD Program, University of Maryland School of Dentistry, Baltimore, MD, USA
- Department of Restorative Dental Sciences, College of Dentistry, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Abdullah A Marghalani
- Department of Preventive Dentistry, Faculty of Dentistry, Um Al-Qura University, Makkah, Saudi Arabia
- Division of Pediatric Dentistry, Department of Orthodontics and Pediatric Dentistry, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - Michael A Raderman
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - Elaine Miginsky
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - Ward Massey
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - Howard Strassler
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD, USA
| | - Mary Anne Melo
- Dental Biomedical Science PhD Program, University of Maryland School of Dentistry, Baltimore, MD, USA
- Division of Operative Dentistry, Department of General Dentistry, University of Maryland School of Dentistry, Baltimore, MD, USA
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12
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Knowledge and Attitude of Dental Clinicians towards Light-Curing Units: A Cross-Sectional Study. Int J Dent 2021; 2021:5578274. [PMID: 34234828 PMCID: PMC8219411 DOI: 10.1155/2021/5578274] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 06/05/2021] [Indexed: 11/18/2022] Open
Abstract
Objectives Light curing is crucial when applying composite resin restorations. Complete polymerization of the resin depends on delivering adequate light energy to it. Dental clinicians may be unaware of the importance of proper light-curing techniques. This study aimed at evaluating and comparing the level of knowledge of general practitioners (GPs) and specialists (SPs) regarding light-curing units. Materials and Methods An electronic survey was conducted online among GPs and SPs of various specialties, working in the governmental sector in Riyadh, Saudi Arabia. Collected data were analyzed for statistical significance. Results 310 dentists were included in the study. Nearly half of the GPs (45.9%) and more than half of SPs (56.8%) use light-emitting diode (LED) type light-curing units (LCUs). 36.9% of GPs and 29.6% of SPs were unsure about the type of LCUs they use in their dental clinics. 10.8% of GPs and 8.5% of SPs knew the proper term of the power output of LCU. 52.2% of the GPs and 55.7% of SPs were wrong about advancements in technology of LED LCUs. Regarding the use of radiometer, 48.2% of SPs and 35.1% of GPs had responded wrongly, and 37.7% of SPs and 52.3% of GPs were not familiar with the device, showing a statistical significance (p=0.040). There was no statistical significance observed in the responses pertaining to their years of experience, expected for two questions. Conclusion Both GPs and SPs displayed inadequate knowledge regarding the use of LCUs. Further educational programs are recommended to spread awareness about the handling of LCUs among dental clinicians.
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13
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Backes CN, FranÇa FMG, Turssi CP, Amaral FLBD, Basting RT. Color stability of a bulk-fill composite resin light-cured at different distances. Braz Oral Res 2020; 34:e119. [PMID: 33146315 DOI: 10.1590/1807-3107bor-2020.vol34.0119] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 07/27/2020] [Indexed: 11/22/2022] Open
Abstract
The aim of this in vitro study was to evaluate the color stability of a bulk-fill (Filtek One Bulk Fill, 3M ESPE) and a conventional (Filtek Z350 XT, 3M ESPE) composite resin light-cured at different distances, before and after being submitted to staining with a coffee solution. Sixty specimens of each composite resin were prepared and light-cured at distances of 0, 2 and 4 mm, using a LED light-curing unit (Valo, Ultradent). The specimens were separated (n = 10) for immersion in either distilled water or coffee solution (10 minutes a day for 8 days) to stimulate staining. Color evaluations were performed before and after immersion in the solutions, according to CIELab (△Eab), CIEDE2000 (△E00) and the Whiteness Index for Dentistry (△WID). Kruskal Wallis and Dunn tests, Mann-Whitney tests and Wilcoxon test were applied (α = 5 %). The a* value for conventional composite resin showed a significant increase after immersion in coffee and distilled water (p < 0.05). Both composite resins showed greater b* values when immersed in coffee than in distilled water, with no significant difference among the light-activation distances (p > 0.05). There was no significant difference for L* among the light-activation distances; both resins showed significant decrease in L* after immersion in coffee (p < 0.05). Color change (△Eab, △E00) and difference in whiteness (△WID) were higher for conventional resin when immersed in the coffee solution at all the light-activation distances. Conventional composite resin presented a higher staining value than bulk-fill composite resin, regardless of the light-activation distance.
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Affiliation(s)
- Christine Nagel Backes
- Faculdade São Leopoldo Mandic - SLMandic, School of Dentistry , Department of Restorative Dentistry, Campinas , SP , Brazil
| | - Fabiana Mantovani Gomes FranÇa
- Faculdade São Leopoldo Mandic - SLMandic, School of Dentistry , Department of Restorative Dentistry, Campinas , SP , Brazil
| | - Cecilia Pedroso Turssi
- Faculdade São Leopoldo Mandic - SLMandic, School of Dentistry , Department of Restorative Dentistry, Campinas , SP , Brazil
| | | | - Roberta Tarkany Basting
- Faculdade São Leopoldo Mandic - SLMandic, School of Dentistry , Department of Restorative Dentistry, Campinas , SP , Brazil
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Lopes GV, Correr-Sobrinho L, Correr AB, Godoi APTD, Vedovello SAS, Menezes CCD. Light Activation and Thermocycling Methods on the Shear Bond Strength of Brackets Bonded to Porcelain Surfaces. Braz Dent J 2020; 31:52-56. [PMID: 32159706 DOI: 10.1590/0103-6440202003101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 09/25/2019] [Indexed: 11/21/2022] Open
Abstract
The present study was evaluated the effect of different light activation and thermocycling methods on the shear bond strength (SBS) and on the adhesive remnant index (ARI) of metal brackets bonded to feldspathic ceramic. Hundred metal brackets were bonded to 20 porcelain cylinders, divided into four groups (n=25) based on light activation and thermocycling processes. The cylinders were etched with 10% hydrofluoric acid for 60 s and coated with two layers of silane. The brackets were bonded with Transbond XT composite resin. Light activation in Groups 1 and 3 was performed during 3 s using the VALO Ortho Cordless appliance with irradiance 3,200 mW/cm2 and in Groups 2 and 4 for 40 s using Optilight Max appliance with irradiance 1,200 mW/cm². The samples were stored in deionized water at 37°C for 24 h and the samples from Groups 1 and 2 were submitted to the SBS test at a rate of 1 mm/min, whereas the samples from Groups 3 and 4 were submitted to 7,000 thermal cycles (5°/55°C) before to the SBS test. The data were assessed by two-way analysis of variance and by Tukey's test (a=0.05). No significant difference was observed between SBS means in the different light activation devices used. The samples subjected to thermocycling revealed lower SBS values (p≤0.05). There was predominance of score 0 for ARI in all groups. Therefore, the different light activation methods did not interfere in SBS, but thermocycling reduced SBS.
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Affiliation(s)
- Gustavo Vallandro Lopes
- Departament of Orthodontics, Centro Universitário da Fundação Hermínio Ometto -FHO, Araras, SP, Brazil
| | - Lourenço Correr-Sobrinho
- Departamento of Restorative Dentistry, Dental Materials, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Américo Bortolazzo Correr
- Departamento of Restorative Dentistry, Dental Materials, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | | | | | - Carolina Carmo de Menezes
- Departament of Orthodontics, Centro Universitário da Fundação Hermínio Ometto -FHO, Araras, SP, Brazil
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15
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Suliman AA, Abdo AA, Elmasmari HA. Training and experience effect on light-curing efficiency by dental practitioners. J Dent Educ 2020; 84:652-659. [PMID: 32064625 DOI: 10.1002/jdd.12113] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 01/06/2020] [Accepted: 01/30/2020] [Indexed: 11/06/2022]
Abstract
BACKGROUND Light-curing is a crucial step during the application of composite resin restorations. Composite's success depends on delivering enough light energy to the resin to achieve adequate polymerization. However, dentists are not recognizing the importance of proper light-curing technique. OBJECTIVES To measure light energy delivered to simulated restorations by preclinical dental students and dentists in internship year. To evaluate the effect of experience and training on the clinician's ability to light-cure composite restorations. METHODS A group of 50 preclinical dental students and a group of 50 internship dentists light-cured for 10 seconds, a simulated class III and class I restorations positioned in a patient simulator (MARC-Patient Simulator [BlueLight Analytics Inc., Canada]) that measured the irradiance and energy delivered by the curing light. Then participants received individualized training on optimizing their light-curing technique. They were retested after the training. Statistical analysis was done with two-way ANOVA and Tukey's test. RESULTS Participants delivered an average of 60% more energy after the instructions, which is a significant improvement (P < 0.05). The number of participants that failed to deliver the minimum amount of energy (6 J/cm²) decreased significantly from 37.5% to 2.5%. There was a significant difference in the amount of energy delivered by the Preclinical and Internship groups (P < 0.05). CONCLUSION Initially, many participants were not using the curing light properly. Light-curing technique improved with training and using a patient simulator. Experience can enhance the operator's ability to light-cure composite restorations. However, a training session can improve light-curing performance more than years of experience.
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Affiliation(s)
| | - Ahmad Ali Abdo
- Restorative Dentistry Department, College of Dentistry, Ajman University, Ajman, UAE
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16
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Suliman AA, Abdo AA, Elmasmari HA. Effect of Contamination, Damage and Barriers on the Light Output of Light-Curing Units. Open Dent J 2019. [DOI: 10.2174/1874210601913010196] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Background:
Light-curing is a crucial step during the application of composite resin restorations. The clinical success of composite depends on the Light-Curing Units (LCU) to deliver adequate light energy to polymerize the resin. However, light-curing usually does not receive the proper awareness it deserves.
Objective:
This study aims to evaluate the effect of contamination and debris of the LCU’s tip on its light output. Determine the effect of damage to the LCU’s tip such as chipping, dents and scratches. Additionally, it evaluates the effect of plastic barrier sleeves.
Methods:
Sixty LED LCUs were tested using MARC™ Resin Calibrator (BlueLight Analytic Inc., Halifax, Canada) to measure their irradiance and energy before and after cleaning their tips. They were also tested with and without a clear plastic barrier. Additionally, four damaged LCUs received new tips and were tested again. Kruskal-Wallis H and One-Way ANOVA tests were used for statistical analysis.
Results:
Cleaning the LCUs’ tips showed significant improvement, an average increase of 8.2%. However, some units increased by up to 47% in irradiance and energy values. Replacing the damaged tip with a new one significantly improved the output of the LCUs, increasing light energy by up to 73%. The barrier used in this study caused 7% reduction in the energy delivered by the LCUs. The statistical analysis showed that cleaning the LCUs and replacing their damaged tips resulted in a significant increase in energy (p<0.05).
Conclusion:
Unclean or damaged LCUs’ tips can drastically reduce the light output of the LCUs, reducing the quality of the composite restorations. Clinicians are strongly recommended to regularly monitor, clean and maintain their curing lights.
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Al-Zain AO, Eckert GJ, Platt JA. The Influence of Distance on Radiant Exposure and Degree of Conversion Using Different Light-Emitting-Diode Curing Units. Oper Dent 2019; 44:E133-E144. [DOI: 10.2341/18-004-l] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Objectives:
To investigate the influence of curing distance on the degree of conversion (DC) of a resin-based composite (RBC) when similar radiant exposure was achieved using six different light-curing units (LCUs) and to explore the correlation among irradiance, radiant exposure, and DC.
Methods and Materials:
A managing accurate resin curing-resin calibrator system was used to collect irradiance data for both top and bottom specimen surfaces with a curing distance of 2 mm and 8 mm while targeting a consistent top surface radiant exposure. Square nanohybrid-dual-photoinitiator RBC specimens (5 × 5 × 2 mm) were cured at each distance (n=6/LCU/distance). Irradiance and DC (micro-Raman spectroscopy) were determined for the top and bottom surfaces. The effect of distance and LCU on irradiance, radiant exposure, and DC as well as their linear associations were analyzed using analysis of variance and Pearson correlation coefficients, respectively (α=0.05).
Results:
While maintaining a similar radiant exposure, each LCU exhibited distinctive patterns in decreased irradiance and increased curing time. No significant differences in DC values (63.21%-70.28%) were observed between the 2- and 8-mm distances, except for a multiple-emission peak LCU. Significant differences in DC were detected among the LCUs. As expected, irradiance and radiant exposure were significantly lower on the bottom surfaces. However, a strong correlation between irradiance and radiant exposure did not necessarily result in a strong correlation with DC.
Conclusions:
The RBC exhibited DC values >63% when the top surface radiant exposure was maintained, although the same values were not reached for all lights. A moderate-strong correlation existed among irradiance, radiant exposure, and DC.
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Affiliation(s)
- AO Al-Zain
- Afnan O Al-Zain, BDS, MSD, PhD, King Abdulaziz University, Faculty of Dentistry, Restorative Dentistry Department, Jeddah, Saudi Arabia
| | - GJ Eckert
- George J Eckert, MS, Indiana University School of Medicine, Division of Biostatistics, Indianapolis, IN, USA
| | - JA Platt
- Jeffrey A Platt, DDS, MS, Indiana University, Department of Biomedical and Applied Sciences, Indianapolis, IN, USA
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18
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Cuevas-Suárez CE, Meereis CTW, D'accorso N, Macchi R, Ancona-Meza AL, Zamarripa-Calderón E. Effect of radiant exposure and UV accelerated aging on physico-chemical and mechanical properties of composite resins. J Appl Oral Sci 2019; 27:e20180075. [PMID: 30624462 PMCID: PMC6322643 DOI: 10.1590/1678-7757-2018-0075] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 09/09/2018] [Indexed: 12/04/2022] Open
Abstract
Currently, there is no consensus in terms of defining the minimum radiant exposure values necessary for achieving adequate properties of composite resin. In addition, the long-term influence that radiant exposure has on the properties of composite resins is still questionable. Objective: The objective of this study was to evaluate the effect of radiant exposure and UV accelerated aging on the physico-chemical and mechanical properties of micro-hybrid and nanofilled composite resins. Material and Methods: A nanofilled (Filtek Supreme; 3M ESPE) and a micro-hybrid composite resin (Filtek Z250; 3M ESPE) were investigated under different radiant exposures (3.75, 9, and 24 J/cm2) and UV accelerated aging protocols (0, 500, 1000, and 1500 aging hours). The degree of conversion (DC), flexural strength (FS), modulus (M), water sorption (WS), and solubility (WL) were evaluated. The results obtained were analyzed using two-way ANOVA and Tukey's test. Comparisons were performed using a significance level of α=0.05. Results: The DC, FS, and M were found to be significantly influenced by both radiant exposure and accelerated aging time. The DC and EM increased with radiant exposure in the no-aging group (0-hour aging) for both micro-hybrid and nanofilled composites, whereas no correlation was found after accelerated aging protocols. WS and WL of micro-hybrid and nanofilled composite resins were scarcely affected by radiant exposure (p>0.05), whereas they were significantly reduced by accelerated aging (p<0.001). Conclusions: Although increasing radiant exposure affected the degree of conversion and mechanical properties of micro-hybrid and nanofilled composites, no influence on the hydrolytic degradation of the material was observed. In contrast, UV accelerated aging affected both the physico-chemical and mechanical properties of the composites.
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Affiliation(s)
- Carlos Enrique Cuevas-Suárez
- Universidad Autónoma del Estado de Hidalgo, Instituto de Ciencias de la Salud, Área Académica de Odontología, Pachuca de Soto, México
| | - Carine Tais Walter Meereis
- Universidade Federal dos Vales do Jequitinhonha e Mucuri, Programa de Pós-Graduação em Odontologia, Diamantina, Minas Gerais, Brasil
| | - Norma D'accorso
- Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Orgánica, Buenos Aires, Argentina
| | - Ricardo Macchi
- Universidad de Buenos Aires, Facultad de Odontología, Departamento de Materiales Dentales, Buenos Aires, Argentina
| | - Adriana Leticia Ancona-Meza
- Universidad Autónoma del Estado de Hidalgo, Instituto de Ciencias de la Salud, Área Académica de Odontología, Pachuca de Soto, México
| | - Eliezer Zamarripa-Calderón
- Universidad Autónoma del Estado de Hidalgo, Instituto de Ciencias de la Salud, Área Académica de Odontología, Pachuca de Soto, México
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Ajaj RA, Nassar HM, Hasanain FA. Infection Control Barrier and Curing Time as Factors Affecting the Irradiance of Light-Cure Units. J Int Soc Prev Community Dent 2018; 8:523-528. [PMID: 30596043 PMCID: PMC6280572 DOI: 10.4103/jispcd.jispcd_226_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 09/18/2018] [Indexed: 11/04/2022] Open
Abstract
Objective The objective of the study is to investigate the effect of infection control barrier (ICB) and curing time on irradiance of light cure units (LCUs). Methods Irradiance (mW/cm2) of the LCUs at a government dental school were recorded with and without ICB at 0 (T0), 10 (T10), and 20 (T20) seconds using a digital radiometer. Data were analyzed using IBM® SPSS® Statistics Version 17 for Windows software for the analysis of variance and Bonferroni methods at 0.05 significance level. Results Using ICB resulted in a statistically significant effect on the irradiance mean (P < 0.01). A significant difference existed between the four different brands of LCUs at different time intervals, irrespective of the use of ICB. At T0 and T10, the mean output of Acteon mini-light-emitting diode (LED) was significantly higher than that of either the Kerr Demi Ultra or the Kavo Polylux II. At T20, E-Morlit's mean irradiance was significantly higher than that of Kerr Demi Ultra, which in turn was significantly higher than that of the Kavo PolyLux II. The mean irradiance of the LEDs was significantly higher than that of the halogens irrespective of barrier placement and at all-time points. Conclusion The ICB used in this study resulted in a statistically significant reduction in the irradiance output. No significant difference in the irradiance was found at different curing time intervals for the tested units regardless of ICB usage.
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Affiliation(s)
- Reem A Ajaj
- Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Hani M Nassar
- Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Fatin A Hasanain
- Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia
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Soares CJ, Rodrigues MDP, Oliveira LRS, Braga SSL, Barcelos LM, Silva GRD, Giannini M, Price RB. An Evaluation of the Light Output from 22 Contemporary Light Curing Units. Braz Dent J 2018; 28:362-371. [PMID: 29297558 DOI: 10.1590/0103-6440201601466] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 03/14/2017] [Indexed: 11/21/2022] Open
Abstract
This study measured the radiant power (mW), irradiance (mW/cm2) and emission spectra (mW/cm2/nm) of 22 new, or almost new, light curing units (LCUs): - Alt Lux II, BioLux Standard, Bluephase G2, Curing Light XL 3000, Demetron LC, DX Turbo LED 1200, EC450, EC500, Emitter C, Emitter D, KON-LUX, LED 3M ESPE, Led Lux II, Optilight Color, Optilight Max, Optilux 501, Poly Wireless, Radii cal, Radii plus, TL-01, VALO Cordless. These LCUs were either monowave or multiple peak light emitting diode (LED) units or quartz-tungsten-halogen LCUs used in anterior and posterior teeth. The radiant power emitted by the LCUs was measured by a laboratory grade laser power meter. The tip area (cm²) of the LCUs was measured and used to calculate the irradiance from the measured radiant power source. The MARC-Patient Simulator (MARC-PS) with a laboratory grade spectrometer (USB4000, Ocean Optics) was used to measure the irradiance and emission spectrum from each LCU three times at the sensor located on the facial of the maxillary central incisors and then separately at the occlusal of a maxillary second molar. The minimum acceptable irradiance level was set as 500 mW/cm2. Irradiance data was analyzed using two-way ANOVA and the radiant power data was analyzed by one-way ANOVA followed by Tukey test (a=0.05). In general, the irradiance was reduced at the molar tooth for most LCUs. Only the Valo, Bluephase G2 and Radii Plus delivered an irradiance similar to the anterior and posterior sensors greater than 500 mW/cm2. KON-LUX, Altlux II, Biolux Standard, TL-01, Optilux 501, DX Turbo LED 1200 LCUs delivered lower irradiance values than the recommended one used in molar region, KON-LUX and Altlux II LCUs used at the maxillary incisors. Bluephase G2 and Optilight Max delivered the highest radiant power and KON-LUX, Altlux II and Biolux Standard delivered the lowest power. The emission spectrum from the various monowave LED LCUs varied greatly. The multi-peak LCUs delivered similar emission spectra to both sensors.
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Affiliation(s)
- Carlos José Soares
- Department of Operative Dentistry, UFU - Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | | | - Laís Rani Sales Oliveira
- Department of Operative Dentistry, UFU - Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | | | - Luciana Mendes Barcelos
- Department of Operative Dentistry, UFU - Universidade Federal de Uberlândia, Uberlândia, MG, Brazil
| | | | - Marcelo Giannini
- Department of Restorative Dentistry, Piracicaba Dental School, UNICAMP - Universidade Estadual de Campinas, Piracicaba, SP, Brazil
| | - Richard Bengt Price
- Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, Canada
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21
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Kaya MS, Bakkal M, Durmus A, Durmus Z. Structural and mechanical properties of a giomer-based bulk fill restorative in different curing conditions. J Appl Oral Sci 2018; 26:e20160662. [PMID: 29364336 PMCID: PMC5777413 DOI: 10.1590/1678-7757-2016-0662] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 08/07/2017] [Indexed: 11/22/2022] Open
Abstract
Objective The main goal of this study was to compare the polymerization degree of bulk-fill giomer resin cured with three different light-curing units (LCUs): a polywave third-generation (Valo); a monowave (DemiUltra: DU); and a second-generation LED (Optima 10: Opt) LCUs by using structural and mechanical properties. Material and methods Giomer samples of 2 and 4 mm cured with three LCUs were employed in vitro analysis. The degree of curing (DC%) was determined with Fourier-Transform Infrared Spectroscopy (FTIR). Microstructural features were observed with scanning electron microscopy (SEM). Flexural strength (FS), compression strength (CS), elastic modulus and fracturing strain were determined for mechanical properties. Surface microhardness (SMH) values were also measured. Oneway ANOVA, two-way analysis of variance and Tukey multiple comparison tests were used for statistically analyzing the FS and SMH. Results DC% values were 58.2, 47.6, and 39.7 for the 2 mm samples cured with DU, Opt., and Valo LCUs, respectively. DC% values of the 4 mm samples were 50.4, 44.6, and 38.2 for DU, Opt, and Valo, respectively. SMH values were Valo, Opt<DU at top of the samples; Valo<DU, Opt at 2 mm, and DU, Valo<Opt at 4 mm depth. Giomer samples cured with Opt and DU exhibited higher FS values than Valo. CS values were similar but compressive modulus and fracturing strain (%) varied depending on the curing protocol. Conclusions Based on the results, it can be concluded that curing device and protocol strongly affect crosslinking reactions and thus DC%, SMH, compressive modulus and strain at break values. Consequently, it can be deduced that curing protocol is possibly the most important parameter for microstructure formation of highly-filled composite restoratives because it may bring some structural defects and physical frailties on restorations due to lower degree of polymerization.
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Affiliation(s)
- Mustafa Sarp Kaya
- Bezmialem Vakif University, Faculty of Dentistry, Department of Pediatric Dentistry, Istanbul, Turkey
| | - Meltem Bakkal
- Bezmialem Vakif University, Faculty of Dentistry, Department of Pediatric Dentistry, Istanbul, Turkey
| | - Ali Durmus
- Istanbul University, Faculty of Engineering, Department of Chemical Engineering, Istanbul, Turkey
| | - Zehra Durmus
- Bezmialem Vakıf University, Faculty of Pharmacy, Department of Pharmaceutical Biotechnology, Istanbul, Turkey
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22
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Geraldeli S, Soares EF, Alvarez AJ, Farivar T, Shields RC, Sinhoreti MAC, Nascimento MM. A new arginine-based dental adhesive system: formulation, mechanical and anti-caries properties. J Dent 2017; 63:72-80. [PMID: 28587978 DOI: 10.1016/j.jdent.2017.05.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 05/27/2017] [Accepted: 05/30/2017] [Indexed: 10/19/2022] Open
Abstract
Secondary caries at the margins of composite restorations has been attributed to adhesive failure and consequent accumulation of cariogenic biofilms. OBJECTIVES To develop and evaluate an etch-and-rinse adhesive system containing arginine for sustainable release and recharge without affecting its mechanical properties. Arginine metabolism by oral bacteria generates ammonia, which neutralizes glycolytic acids and creates a neutral environmental pH that is less favorable to the growth of caries pathogens, thus reducing the caries risk at the tooth-composite interface. METHODS Experimental adhesives were formulated with methacrylate monomers and arginine at 5%, 7%, and 10% or no arginine (control). Adhesives were tested for: (i) mechanical properties of true stress (FS and UTS), modulus of elasticity (E), degree of conversion (DC), Knoop hardness number (KHN) and dentin microtensile bond strength (μ-TBS), (ii) arginine release and recharge, and (iii) antibacterial activities. Data was analyzed by t-test, one-way ANOVA and Tukey's tests. RESULTS FS and UTS results showed no statistically significant differences between the 7% arginine-adhesive and control, while the results for E, DC, KHN and μ-TBS showed no difference among all groups. The 7% arginine-adhesive showed a high release rate of arginine (75.0μmol/cm2) at 2h, and a more sustainable, controlled release rate (up to 0.2μmol/cm2) at 30days. CONCLUSIONS Incorporation of 7% arginine did not affect the physical and mechanical properties of the adhesive. Arginine was released from the adhesive at a rate and concentration that exhibited antibacterial effects, regardless of shifts in biofilm conditions such as sugar availability and pH. CLINICAL SIGNIFICANCE Secondary caries is recognized as the main reason for failure of dental restorations. The development of an arginine-based adhesive system has the potential to dramatically reduce the incidence and severity of secondary caries in adhesive restorations in a very economical fashion.
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Affiliation(s)
- Saulo Geraldeli
- Department of Restorative Dental Sciences, Division of Operative Dentistry, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Eveline F Soares
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Andres J Alvarez
- College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Tanaz Farivar
- Department of Restorative Dental Sciences, Division of Operative Dentistry, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Robert C Shields
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Mario A C Sinhoreti
- Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Marcelle M Nascimento
- Department of Restorative Dental Sciences, Division of Operative Dentistry, College of Dentistry, University of Florida, Gainesville, FL, USA.
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AlShaafi MM. Factors affecting polymerization of resin-based composites: A literature review. Saudi Dent J 2017; 29:48-58. [PMID: 28490843 PMCID: PMC5411902 DOI: 10.1016/j.sdentj.2017.01.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/28/2017] [Accepted: 01/29/2017] [Indexed: 11/15/2022] Open
Abstract
AIM The aim of this review was to help clinicians improve their understanding of the polymerization process for resin-based composites (RBC), the effects of different factors on the process and the way in which, when controlled, the process leads to adequately cured RBC restorations. METHODS Ten factors and their possible effects on RBC polymerization are reviewed and discussed, with some recommendations to improve that process. These factors include RBC shades, their light curing duration, increment thickness, light unit system used, cavity diameter, cavity location, light curing tip distance from the curing RBC surface, substrate through which the light is cured, filler type, and resin/oral cavity temperature. CONCLUSION The results of the review will guide clinicians toward the best means of providing their patients with successfully cured RBC restorations.
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Affiliation(s)
- Maan M AlShaafi
- Department of Restorative Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
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Soares CJ, Rodrigues MDP, Vilela ABF, Rizo ERC, Ferreira LB, Giannini M, Price RB. Evaluation of Eye Protection Filters Used with Broad-Spectrum and Conventional LED Curing Lights. Braz Dent J 2017; 28:9-15. [DOI: 10.1590/0103-6440201701380] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 12/13/2016] [Indexed: 01/25/2023] Open
Abstract
Abstract The high irradiance and the different emission spectra from contemporary light curing units (LCU) may cause ocular damage. This study evaluated the ability of 15 eye protection filters: 2 glasses, 1 paddle design, and 12 dedicated filters to block out harmful light from a monowave (HP-3M ESPE) and a broad-spectrum (Valo, Ultradent) LED LCU. Using the anterior sensor in the MARC-Patient Simulator (BlueLight Analytics) the irradiance that was delivered through different eye protection filters was measured three times. The LCUs delivered a similar irradiance to the top of the filter. The mean values of the light that passed through the filters as percent of the original irradiance were analyzed using two-way ANOVA followed by Tukey test (a= 0.05). The emission spectra from the LCUs and through the filters were also obtained. Two-way ANOVA showed that the interaction between protective filters and LCUs significantly influenced the amount of light transmitted (p< 0.001). Tukey test showed that the amount of light transmitted through the protective filters when using the HP-3M-ESPE was significantly greater compared to when using the Valo, irrespective of the protective filter tested. When using the HP-3M-ESPE, the Glasses filter allowed significantly more light through, followed by XL 3000, ORTUS, Google Professional, Gnatus filters. The Valo filter was the most effective at blocking out the harmful light. Some protective filters were less effective at blocking the lower wavelengths of light (<420 nm). However, even in the worst scenario, the filters were able to block at least 97% of the irradiance.
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Uusitalo E, Varrela J, Lassila L, Vallittu PK. Transmission of Curing Light through Moist, Air-Dried, and EDTA Treated Dentine and Enamel. BIOMED RESEARCH INTERNATIONAL 2016; 2016:5713962. [PMID: 27446954 PMCID: PMC4944042 DOI: 10.1155/2016/5713962] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 05/16/2016] [Accepted: 06/05/2016] [Indexed: 11/17/2022]
Abstract
Objective. This study measured light transmission through enamel and dentin and the effect of exposed dentinal tubules to light propagation. Methods. Light attenuation through enamel and dentin layers of various thicknesses (1 mm, 2 mm, 3 mm, and 4 mm) was measured using specimens that were (1) moist and (2) air-dried (n = 5). Measurements were repeated after the specimens were treated with EDTA. Specimens were transilluminated with a light curing unit (maximum power output 1869 mW/cm(2)), and the mean irradiance power of transmitting light was measured. The transmission of light through teeth was studied using 10 extracted intact human incisors and premolars. Results. Transmitted light irradiance through 1 mm thick moist discs was 500 mW/cm(2) for enamel and 398 mW/cm(2) for dentin (p < 0.05). The increase of the specimen thickness decreased light transmission in all groups (p < 0.005), and moist specimens attenuated light less than air-dried specimens in all thicknesses (p < 0.05). EDTA treatment increased light transmission from 398 mW/cm(2) to 439 mW/cm(2) (1 mm dentin specimen thickness) (p < 0.05). Light transmission through intact premolar was 6.2 mW/cm(2) (average thickness 8.2 mm) and through incisor was 37.6 mW/cm(2) (average thickness 5.6 mm). Conclusion. Light transmission through enamel is greater than that through dentin, probably reflecting differences in refractive indices and extinction coefficients. Light transmission through enamel, dentin, and extracted teeth seemed to follow Beer-Lambert's law.
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Affiliation(s)
- E. Uusitalo
- Institute of Dentistry, University of Turku, 20520 Turku, Finland
| | - J. Varrela
- Institute of Dentistry, University of Turku, 20520 Turku, Finland
- City of Turku Division of Welfare, 20520 Turku, Finland
- Department of Oral Development and Orthodontics, University of Turku, 20520 Turku, Finland
| | - L. Lassila
- Department of Biomaterials Science and Turku Clinical Biomaterials Centre (TCBC), 20520 Turku, Finland
| | - P. K. Vallittu
- Institute of Dentistry, University of Turku, 20520 Turku, Finland
- City of Turku Division of Welfare, 20520 Turku, Finland
- Department of Biomaterials Science and Turku Clinical Biomaterials Centre (TCBC), 20520 Turku, Finland
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