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Najjar YM, Burhan AS, Hajeer MY, Nawaya FR. Effects of the conventional, soft start, and pulse delay modes produced by light-emitting diode device on microleakage beneath metal brackets: An in vitro comparative study. Int Orthod 2023; 21:100718. [PMID: 36516656 DOI: 10.1016/j.ortho.2022.100718] [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] [Received: 10/26/2022] [Revised: 11/25/2022] [Accepted: 11/27/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND This study aimed to evaluate microleakage beneath metal brackets cured by different light curing modes. MATERIALS AND METHODS Sixty extracted human premolars were randomly divided into three groups according to the light curing mode. Metal brackets were bonded in all groups according to the manufacturer's recommendations with a light-emitting diode device. Light curing was applied as follows: group 1: conventional mode (10 s mesial+10 s distal); group 2: soft start mode (15 s mesial+15 s distal); group 3: pulse delay mode (3 s mesial+3 s distal, followed by 3min of no photoactivation, then 9 s mesial+9 s distal). Radiant exposure was the same in all study groups. After curing, the teeth were incubated at 37 degrees for 24hours, then thermocycled 500 times. Next, they were sealed with nail varnish, immersed in methylene blue 1% for 24hours, sectioned, and examined under a stereomicroscope. Microleakage was measured at both enamel-adhesive and bracket-adhesive interfaces, and the total microleakage for each tooth was computed. Statistical analyses were performed using Kruskal-Wallis and Welch test for comparing microleakage among groups. Wilcoxon signed ranks test was used for comparing microleakage between the bracket-adhesive and enamel-adhesive interfaces. RESULTS There was no significant difference in microleakage at the bracket-adhesive interface among study groups. At the enamel-adhesive interface and total microleakage, the pulse delay group exhibited significantly lower microleakage than the conventional group. Whereas there was no significant difference between the soft start group and other study groups. In all study groups, microleakage at the enamel-adhesive interface was greater than that at the bracket-adhesive interface. CONCLUSION The pulse delay mode caused lesser microleakage than the conventional mode. This supports the use of this mode in orthodontic bonding.
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Affiliation(s)
| | - Ahmad S Burhan
- Department of Orthodontics, University of Damascus Dental School, Damascus, Syria
| | - Mohammad Y Hajeer
- Department of Orthodontics, University of Damascus Dental School, Damascus, Syria.
| | - Fehmieh R Nawaya
- Department of Pediatric Dentistry, Faculty of Dentistry, Syrian Private University, Damascus countryside, Syria
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Amiri P, Talebi Z, Semnani D, Bagheri R, Fashandi H. Improved performance of Bis-GMA dental composites reinforced with surface-modified PAN nanofibers. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2021; 32:82. [PMID: 34191135 PMCID: PMC8245374 DOI: 10.1007/s10856-021-06557-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Accepted: 06/07/2021] [Indexed: 06/13/2023]
Abstract
In the present work, polyacrylonitrile (PAN) nanofibers reinforced dental composites were investigated to achieve the improved interfacial adhesion between the PAN nanofiber and resin matrix using surface modification of nanofibers. PAN nanofibers mat were prepared by electrospinning and then, surface treated with the activated bisphenol A glycidyl methacrylate (Bis-GMA)/triethyleneglycol dimethacrylate (TEGDMA) (50/50 mass ratio) dental resin followed by photo-curing. Also, the treated nanofibers mat was milled into a powder to achieve the uniform distribution of nanofibers in the matrix resin. The reinforced dental composite were prepared by mixing the various mass fraction of the powder (0.5-15 wt%) with the Bis-GMA/TEGDMA dental monomers. The effect of weight ratio of surface-modified nanofibers to blend resin on the chemical structure, morphology, compression and flexural properties, color and polymerization shrinkage of dental composites was evaluated. The results showed that using surface-treated nanofibers with content of 5 wt% enhanced the compression strength, flexural strength, flexural modulus and work of rupture of the resultant dental composite by factors of 23%, 7%, 80%, and 145%, respectively, comparing to the unreinforced neat resin. Also, the polymerization shrinkage reduces by 37%. These significant improved properties of the dental composite could be due to the semi-interpenetration network formation between surface-modified nanofibers and resin matrix and well distribution of nanofibers in the dental resin. Further increasing the nanofiber content led to poor mechanical properties of obtained dental composites. The results also, revealed that the color of resin composite could be whiter using modified PAN nanofibers as the filler.
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Affiliation(s)
- Parisa Amiri
- Department of Textile Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | - Zahra Talebi
- Department of Textile Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran.
| | - Dariush Semnani
- Department of Textile Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | - Rouhollah Bagheri
- Department of Chemical Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
| | - Hossein Fashandi
- Department of Textile Engineering, Isfahan University of Technology, Isfahan, 84156-83111, Iran
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Kim K, Sinha J, Gao G, Childress KK, Sartor SM, Salazar AM, Huang S, Musgrave CB, Stansbury JW. High-Efficiency Radical Photopolymerization Enhanced by Autonomous Dark Cure. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c01023] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Kangmin Kim
- Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Jasmine Sinha
- Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Guangzhe Gao
- Materials Science and Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Kimberly K. Childress
- Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Steven M. Sartor
- Chemistry, University of Colorado, Boulder, Colorado 80309, United States
| | - Austyn M. Salazar
- Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Sijia Huang
- Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
| | - Charles B. Musgrave
- Chemistry, University of Colorado, Boulder, Colorado 80309, United States
- Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
- Materials Science and Engineering, University of Colorado, Boulder, Colorado 80309, United States
- National Renewable Energy Laboratory, Golden, Colorado 80401, United States
| | - Jeffrey W. Stansbury
- Chemical and Biological Engineering, University of Colorado, Boulder, Colorado 80309, United States
- Craniofacial Biology, School of Dental Medicine, Aurora, Colorado 80045, United States
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Effect of pulse width modulation-controlled LED light on the polymerization of dental composites. Dent Mater 2018; 34:1836-1845. [DOI: 10.1016/j.dental.2018.10.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 11/20/2022]
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Lima ACD, Rached-Junior FJ, Faria NSD, Messias DC, Chaves CDAL, Freitas JVD, Baratto-Filho F, Silva-Sousa YTC. Influence of Sealer and Light-Curing Units on Push-Out Bond Strength Of Composite Resin to Weakened Roots. Braz Dent J 2017; 27:430-5. [PMID: 27652706 DOI: 10.1590/0103-6440201601010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 08/12/2016] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to assess the influence of sealer and light-curing unit on regional bond strength of resin composite to the weakened roots. Ninety roots of incisors were experimentally weakened, subjected to biomechanical preparation and filled with either Endofill, AH Plus or MTA Fillapex The roots were desobturated e reinforced with resin composite and fiber post light-activated with one of the light sources: halogen at 600 mW/ cm2 (QTH-600), LED at 800 mW/ cm2 (LED-800) and LED at 1500 mW/ cm2 (LED-1500). The roots were sectioned in slices from cervical, middle and apical root-reinforcement regions and analyzed by push out test, scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Bond strength data were analyzed using three-way ANOVA and Tukey´s test (α=0.05). Specimens filled with AH Plus had higher bond strength, followed by MTA Fillapex and Endofill (p<0.05). For light-curing unit, LED-1500 presented superior bond strength than LED-800, which was higher than QTH-600 (p<0.05). The cervical region had the greatest mean values (p<0.05) while apical part showed the lowest bond strength (p<0.05). CLMS revealed remaining filling material in the dentinal tubules for all groups. The eugenol-containing sealer (Endofill) compromised the push-out bond strength of composite resin to the root dentin. Bond strength was favored in the cervical region, and when LED-1500 was used.
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Shrinkage behaviors of dental composite restorations—The experimental–numerical hybrid analysis. Dent Mater 2016; 32:e362-e373. [DOI: 10.1016/j.dental.2016.09.022] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 02/15/2016] [Accepted: 09/03/2016] [Indexed: 11/20/2022]
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Li MZ, Wang JR, Liu H, Wang X, Gan K, Liu XJ, Niu DL, Song XQ. Effects of light curing modes and ethanol-wet bonding on dentin bonding properties. J Zhejiang Univ Sci B 2016; 17:703-11. [PMID: 27604862 DOI: 10.1631/jzus.b1600055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE This study explored the effects of different light curing modes and ethanol-wet bonding on dentin bonding strength and durability. METHODS A total of 54 molars were randomly divided into three groups: Single Bond 2, Gluma Comfort Bond, and N-Bond. Based on the three light-curing modes and presence or absence of ethanol pretreatment, the samples were assigned to six subgroups: high-light mode, ethanol pretreatment+high-light mode, soft-start mode, ethanol pretreatment+soft-start mode, standard mode, and ethanol pretreatment+standard mode. All samples were bonded with resin based on the experimental groups. After 24 h and 6 months of water storage, a universal testing machine was used to measure microtensile bond strength. Scanning electron microscopy (SEM) was applied to observe mixed layer morphology. RESULTS The 24-h and 6-month microtensile bond strengths of the ethanol pretreatment groups were significantly higher than those of the non-ethanol pretreatment groups at the same light modes (P<0.05). With or without ethanol pretreatment, the microtensile bond strengths of the high-light modes were significantly lower than those of the soft-start modes and standard modes (P<0.05). The microtensile bond strengths of samples from the 6-month water storage group significantly decreased compared with those of samples from the 24-h water storage group (P<0.05). The soft-start groups and standard groups formed better mixed layers than the high-light mode groups, whereas the ethanol pretreatment groups formed more uniform mixed layers than those without ethanol pretreatment. CONCLUSIONS Ethanol-wet bonding technique, soft-start, and standard modes could improve dentin bonding properties.
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Affiliation(s)
- Mu-Zi Li
- School and Hospital of Stomatology, Jilin University, Changchun 130021, China.,Jilin Provincial Key Laboratory of Tooth Development and Remodeling, Changchun 130021, China
| | - Jin-Rui Wang
- School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - Hong Liu
- School and Hospital of Stomatology, Jilin University, Changchun 130021, China.,Jilin Provincial Key Laboratory of Tooth Development and Remodeling, Changchun 130021, China
| | - Xia Wang
- School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - Kang Gan
- School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - Xiu-Ju Liu
- School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - De-Li Niu
- School and Hospital of Stomatology, Jilin University, Changchun 130021, China
| | - Xiao-Qing Song
- School and Hospital of Stomatology, Jilin University, Changchun 130021, China
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Three-year clinical evaluation of class II posterior composite restorations placed with different techniques and flowable composite linings in endodontically treated teeth. Clin Oral Investig 2016; 21:709-716. [PMID: 27538739 DOI: 10.1007/s00784-016-1940-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 08/10/2016] [Indexed: 10/21/2022]
Abstract
OBJECTIVE The objective of this study is to evaluate the clinical performance of direct resin composite restorations placed with different techniques (incremental or bulk) and different flowable linings (conventional or bulk-fill) in endodontically treated teeth. MATERIALS AND METHODS Forty-seven pair class II (mesio-occlusal or disto-occlusal) composite restorations were placed in 37 patients. In all cavities, Adper Single Bond 2 was used. In one of the cavities of each pair, a conventional flowable composite, Aelite Flo, was applied in approximately 2 mm thick, and the remaining cavity was restored incrementally with GrandioSO. In the second cavity, a bulk-fill flowable composite, x-tra base, was applied in approximately 4 mm thick in bulk increments and the remaining 2-mm occlusal part of the cavity was restored with GrandioSO. All cavities were restored with open-sandwich technique by the same operator. At baseline and after 6-month, 1-, 2-, and 3-year follow-up visits, restorations were evaluated by modified USPHS criteria. RESULTS At 3-year recall, 33 restorations with Aelite Flo lining and 33 with x-tra base lining were available. Two restorations from each group (6.0 %) were scored as Bravo in terms of surface texture. One restoration's color match from x-tra base group scored as Bravo (3.0 %). All other evaluated criteria were scored as Alfa (100 %) for all restorations. No statistically significant difference between the two groups was found in all evaluated criteria during 3-year period (p > 0.05). CONCLUSION Bulk-filling technique showed clinically acceptable performance comparable to the incremental technique. CLINICAL RELEVANCE Restorations placed with bulk-filling technique with x-tra base lining and incremental technique with a conventional flowable lining showed highly clinical performance over 3-year period.
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LMP C, Boaro LC, LKG S, Parra DF, Lugão AB. Influence of ionizing radiation on the mechanical properties of BisGMA/TEGDMA based experimental resin. Radiat Phys Chem Oxf Engl 1993 2015. [DOI: 10.1016/j.radphyschem.2015.06.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Tauböck TT, Feilzer AJ, Buchalla W, Kleverlaan CJ, Krejci I, Attin T. Effect of modulated photo-activation on polymerization shrinkage behavior of dental restorative resin composites. Eur J Oral Sci 2015; 122:293-302. [PMID: 25039287 DOI: 10.1111/eos.12139] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2014] [Indexed: 11/30/2022]
Abstract
This study investigated the influence of modulated photo-activation on axial polymerization shrinkage, shrinkage force, and hardening of light- and dual-curing resin-based composites. Three light-curing resin composites (SDR bulk-fill, Esthet X flow, and Esthet X HD) and one dual-curing material (Rebilda DC) were subjected to different irradiation protocols with identical energy density (27 J cm(-2) ): high-intensity continuous light (HIC), low-intensity continuous light (LIC), soft-start (SS), and pulse-delay curing (PD). Axial shrinkage and shrinkage force of 1.5-mm-thick specimens were recorded in real time for 15 min using custom-made devices. Knoop hardness was determined at the end of the observation period. Statistical analysis revealed no significant differences among the curing protocols for both Knoop hardness and axial shrinkage, irrespective of the composite material. Pulse-delay curing generated the significantly lowest shrinkage forces within the three light-curing materials SDR bulk-fill, Esthet X flow, and Esthet X HD. High-intensity continuous light created the significantly highest shrinkage forces within Esthet X HD and Rebilda DC, and caused significantly higher forces than LIC within Esthet X flow. In conclusion, both the composite material and the applied curing protocol control shrinkage force formation. Pulse-delay curing decreases shrinkage forces compared with high-intensity continuous irradiation without affecting hardening and axial polymerization shrinkage.
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Affiliation(s)
- Tobias T Tauböck
- Department of Preventive Dentistry, Periodontology and Cariology, Center for Dental Medicine, University of Zurich, Zurich, Switzerland
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Baba NZ, Goodacre CJ. Restoration of endodontically treated teeth: contemporary concepts and future perspectives. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/etp.12066] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Son SA, Roh HM, Hur B, Kwon YH, Park JK. The effect of resin thickness on polymerization characteristics of silorane-based composite resin. Restor Dent Endod 2014; 39:310-8. [PMID: 25383351 PMCID: PMC4223102 DOI: 10.5395/rde.2014.39.4.310] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2014] [Accepted: 07/23/2014] [Indexed: 11/16/2022] Open
Abstract
Objectives This study examined the influence of the resin thickness on the polymerization of silorane- and methacrylate-based composites. Materials and Methods One silorane-based (Filtek P90, 3M ESPE) and two methacrylate-based (Filtek Z250 and Z350, 3M ESPE) composite resins were used. The number of photons were detected using a photodiode detector at the different thicknesses (thickness, 1, 2 and 3 mm) specimens. The microhardness of the top and bottom surfaces was measured (n = 15) using a Vickers hardness with 200 gf load and 15 sec dwell time conditions. The degree of conversion (DC) of the specimens was determined using Fourier transform infrared spectroscopy (FTIR). Scratched powder of each top and bottom surface of the specimen dissolved in ethanol for transmission FTIR spectroscopy. The refractive index was measured using a Abbe-type refractometer. To measure the polymerization shrinkage, a linometer was used. The results were analyzed using two-way ANOVA and Tukey's test at p < 0.05 level. Results The silorane-based resin composite showed the lowest filler content and light attenuation among the specimens. P90 showed the highest values in the DC and the lowest microhardness at all depth. In the polymerization shrinkage, P90 showed a significantly lower shrinkage than the rest two resin products (p < 0.05). P90 showed a significantly lower refractive index than the remaining two resin products (p < 0.05). Conclusions DC, microhardness, polymerization rate and refractive index linearly decreased as specimen thickness linearly increased. P90 showed much less polymerization shrinkage compared to other specimens. P90, even though achieved the highest DC, showed the lowest microhardness and refractive index.
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Affiliation(s)
- Sung-Ae Son
- Department of Conservative Dentistry, School of Dentistry, Pusan National University, Yangsan, Korea
| | - Hyoung-Mee Roh
- Department of Conservative Dentistry, School of Dentistry, Pusan National University, Yangsan, Korea
| | - Bock Hur
- Department of Conservative Dentistry, School of Dentistry, Pusan National University, Yangsan, Korea
| | - Yong-Hoon Kwon
- Department of Dental Materials, School of Dentistry, Pusan National University, Yangsan, Korea
| | - Jeong-Kil Park
- Department of Conservative Dentistry, School of Dentistry, Pusan National University, Yangsan, Korea
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Machado RP, Chaves CDAL, Rached-Junior FJA, Souza CJD, Messias DC, Silva-Sousa YC. Effect of Light Sources on the Bond Strength of Resin Material to Thin-walled Roots. Braz Dent J 2014; 25:225-31. [DOI: 10.1590/0103-6440201302427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 06/03/2014] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to evaluate the bond strength to the dentin of an adhesive material used for root reinforcement light activated with different sources. Roots were divided into 4 groups (n=15) according to the light source used to activate the resin reinforcement: GI, non-weakened roots (control); GII, halogen light (H) 600 mW/cm2; GIII, LED 800 mW/cm2 and GIV, LED 1500 mW/cm2. The reinforcement was done with adhesive, composite resin and fiberglass posts. After 24 h, the specimens were sectioned and the first slice of each post region was used in the push out test in a universal testing machine with a crosshead speed of 0.5 mm/min. Failure modes of the debonded specimens were examined. Data (MPa) were analyzed by ANOVA and Holm-Sidak test (=0.05). The second slice from each region was analyzed by scanning electron microscopy (SEM). LED-1500 (4.69 ± 1.74) provided bond strength similar to the control group (5.05 ± 2.63) and statistically different from H-600 (1.96 ± 0.94) and LED-800 (2.75 ± 1.90), which were similar to each other (p<0.05). Cervical (4.16 ± 2.32) and middle (4.43 ± 2.32) regions showed higher bond strength than the apical (2.25 ± 1.50) (p<0.05). There was a prevalence of adhesive failures in H-600 and LED-800 and cohesive failures in LED-1500. SEM showed the formation of long, numerous and fine tags. It was concluded that LED-1500 provided higher bond strength of resin reinforcement to the dentin.
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Dirxen C, Blunck U, Preissner S. Clinical performance of a new biomimetic double network material. Open Dent J 2013; 7:118-22. [PMID: 24167534 PMCID: PMC3807582 DOI: 10.2174/1874210620130904003] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 07/30/2013] [Accepted: 08/02/2013] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND The development of ceramics during the last years was overwhelming. However, the focus was laid on the hardness and the strength of the restorative materials, resulting in high antagonistic tooth wear. This is critical for patients with bruxism. OBJECTIVES The purpose of this study was to evaluate the clinical performance of the new double hybrid material for non-invasive treatment approaches. MATERIAL AND METHODS The new approach of the material tested, was to modify ceramics to create a biomimetic material that has similar physical properties like dentin and enamel and is still as strong as conventional ceramics. RESULTS The produced crowns had a thickness ranging from 0.5 to 1.5 mm. To evaluate the clinical performance and durability of the crowns, the patient was examined half a year later. The crowns were still intact and soft tissues appeared healthy and this was achieved without any loss of tooth structure. CONCLUSIONS The material can be milled to thin layers, but is still strong enough to prevent cracks which are stopped by the interpenetrating polymer within the network. Depending on the clinical situation, minimally- up to non-invasive restorations can be milled. CLINICAL RELEVANCE Dentistry aims in preservation of tooth structure. Patients suffering from loss of tooth structure (dental erosion, Amelogenesis imperfecta) or even young patients could benefit from minimally-invasive crowns. Due to a Vickers hardness between dentin and enamel, antagonistic tooth wear is very low. This might be interesting for treating patients with bruxism.
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Affiliation(s)
- Christine Dirxen
- Charité - Universitätsmedizin Berlin, Department of Operative and Preventive Dentistry, Assmannshauser Straße 4-6, 14197 Berlin, Germany
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Shafiei F, Akbarian S. The effect of LED curing mode on microleakage of Class V cavity restored by silorane-based composite. Acta Odontol Scand 2013; 71:1162-7. [PMID: 23294117 DOI: 10.3109/00016357.2012.757357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE This in vitro study evaluated the effect of soft-start curing mode by LED unit on the marginal microleakage of silorane composite restoration. MATERIALS AND METHODS Class V cavities were prepared on the buccal surfaces of 80 extracted molars at the cementoenamel junction and randomly divided into eight groups. In groups 1-4, four adhesive/composite combinations (silorane/silorane, silorane/Z250, Adper Single Bond/Z250, Clearfil SE Bond/Clearfil AP-X) were applied and the composites were cured under standard mode at 1500 mW/cm(2) for 20 s. In the other four groups, after applying the same adhesive/composite combinations, the composites were cured at 550 mW/cm(2) for 10 s followed at 1500 mW/cm(2) for 15 s. After 24 h of water storage and thermocycling, the specimens were placed in 1% methylene blue solution. The dye penetration was assessed under a stereomicroscope. The data were analysed using non-parametric tests. RESULTS There were no significant differences among four groups for two curing modes at the occlusal and gingival margins (p > 0.05). The soft-start curing had a positive effect on the gingival marginal sealing of group 1 (p < 0.05), but not for the other three groups (p > 0.05). CONCLUSION The beneficial effect of relatively high soft-start curing on marginal sealing of Class V restoration depends on a combination of the adhesive and composite types, having a positive effect on silorane adhesive/silorane-based composite at the gingival margin.
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Affiliation(s)
- Fereshteh Shafiei
- Department of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran
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Mikhail SS, Schricker SR, Azer SS, Brantley WA, Johnston WM. Optical characteristics of contemporary dental composite resin materials. J Dent 2013; 41:771-8. [DOI: 10.1016/j.jdent.2013.07.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 07/01/2013] [Accepted: 07/03/2013] [Indexed: 12/18/2022] Open
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Influence of light-curing mode on the erosion preventive effect of three different resin-based surface sealants. Int J Dent 2012; 2012:874359. [PMID: 22991513 PMCID: PMC3443587 DOI: 10.1155/2012/874359] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 07/09/2012] [Accepted: 08/08/2012] [Indexed: 11/17/2022] Open
Abstract
Objectives. To investigate if reducing the light-curing time (while maintaining similar energy density) of resin-based surface sealants influences their erosion-preventive potential and mechanical stability after thermomechanical loading. Methods. Dentine samples were treated as follows: group 1—untreated, groups 2–4—Seal&Protect, groups 5–7—experimental sealer, and groups 8–10—Syntac Classic system. Groups 2, 5 and 8 were light-cured for 10 s (1000 mW/cm2), groups 3, 6 and 9 for 7 s (1400 mW/cm2), and groups 4, 7, and 10 for 3 s (3200 mW/cm2). After water storage (7 d), first measurement was performed to evaluate baseline permeability of the sealants. After a thermomechanical loading (5000 cycles, 50/5°C, 12000 brushing strokes) a second evaluation of permeability was conducted (measurement 2). Permeability was tested by storing the samples in HCl (pH 2.3; 24 h) and measuring the dentine calcium release by atomic absorption spectroscopy. Results. For the first and second measurements, no influence of light-exposure time on permeability was observed (ANOVA: P > 0.05). No significant difference in the stability of the respective sealants was observed when light-cured for different durations. Conclusion. Shortening the light-curing time, while maintaining energy density constant, has no influence on permeability and stability of the investigated sealants.
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GAO BT, LIN H, ZHENG G, XU YX, YANG JL. Comparison between a silorane-based composite and methacrylate-based composites: Shrinkage characteristics, thermal properties, gel point and vitrification point. Dent Mater J 2012; 31:76-85. [DOI: 10.4012/dmj.2011-147] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Duan Y, Li J, Zhong W, Maguire RG, Zhao G, Xie H, Li D, Lu B. Effects of compaction and UV exposure on performance of acrylate/glass-fiber composites cured layer by layer. J Appl Polym Sci 2011. [DOI: 10.1002/app.34909] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Taha N, Palamara J, Messer H. Fracture strength and fracture patterns of root filled teeth restored with direct resin restorations. J Dent 2011; 39:527-35. [DOI: 10.1016/j.jdent.2011.05.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Revised: 05/10/2011] [Accepted: 05/11/2011] [Indexed: 11/24/2022] Open
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Tauböck TT, Bortolotto T, Buchalla W, Attin T, Krejci I. Influence of light-curing protocols on polymerization shrinkage and shrinkage force of a dual-cured core build-up resin composite. Eur J Oral Sci 2010; 118:423-9. [DOI: 10.1111/j.1600-0722.2010.00746.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Teixeira CS, Silva-Sousa YTC, Sousa-Neto MD. Bond strength of fiber posts to weakened roots after resin restoration with different light-curing times. J Endod 2009; 35:1034-9. [PMID: 19567329 DOI: 10.1016/j.joen.2009.04.018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 04/11/2009] [Accepted: 04/13/2009] [Indexed: 11/30/2022]
Abstract
INTRODUCTION This study evaluated the bond strength of translucent fiber posts to experimentally weakened radicular dentin restored with composite resin and polymerized with different light-exposure time. METHODS Roots of 60 maxillary incisors were used. Twenty-four hours after obturation, the filling materials of root canals were removed to a depth of 12 mm, and 4 groups were randomly formed. In 3 groups, root dentin was flared to produce a space between fiber post and canal walls. In the control group, the roots were not experimentally weakened. The flared roots were bulk restored with composite resin, which was light-activated through the translucent post for 40, 80, or 120 seconds. Posts were cemented, and after 24 hours, all roots were sectioned transversely in the coronal, middle, and apical regions, producing 1-mm-thick slices. Push-out test was performed, and failure modes were observed. RESULTS The quantitative analysis showed significant statistical difference only among groups (P < .001). Comparing the weakened/restored groups, composite light-exposure time did not influence the results. Overall, adhesive failures occurred more frequently than other types of failures. Cohesive failures occurred only in the weakened/restored roots. CONCLUSIONS Intracanal root restoration with composite resin and translucent fiber posts provided similar or higher bond strength to dentin than the control group, regardless of the light-exposure time used for polymerization.
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Cuspal deflection, strain and microleakage of endodontically treated premolar teeth restored with direct resin composites. J Dent 2009; 37:724-30. [DOI: 10.1016/j.jdent.2009.05.027] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2009] [Revised: 05/26/2009] [Accepted: 05/30/2009] [Indexed: 11/20/2022] Open
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Dalli'Magro E, Sinhoreti MAC, Correr AB, Consani RLX, Sicoli EA, Mendoça MJ, Correr-Sobrinho L. Effect of different modes of light modulation on the bond strength and knoop hardness of a dental composite. Braz Dent J 2009; 19:334-40. [PMID: 19180324 DOI: 10.1590/s0103-64402008000400009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2008] [Accepted: 09/11/2008] [Indexed: 11/22/2022] Open
Abstract
This study evaluated the bond strength and Knoop hardness of Z250 composite resin, light activated with XL2500 curing unit, using different protocols: continuous mode - high intensity (CH) (700 mW/cm(2)) for 20 s; continuous mode - low intensity (CL) (150 mW/cm(2)) for 20 s; and pulse-delay with 150 mW/cm(2) for 2(P2), 3(P3), 5(P5), 10(P10) or 15 s (P15), with a 1-min delay, followed by 700 mW/cm(2) for 20 s. For the push-out test (n=10), the bond strength values were obtained using a universal test machine at a crosshead speed of 0.5 mm/min. For Knoop hardness (n=5), the specimens were made using the same light-activation protocols. The hardness measurements were made with a hardness tester at six depths (top, 1, 2, 3, 4, and 5 mm). The data were subjected to ANOVA and Tukey's test at 5% significance level. For bond strength, CL and P5 presented significantly higher mean values (p<0.05) than the other groups. There was no statistically significant difference (p>0.05) between P2, P3, P10, P15 and CH. For Knoop hardness, CH and P15 presented the highest mean values from top surface up to 4 mm depth , while CL presented the lowest hardness mean values (p<0.05). From the depth of 3 mm to 5 mm, the mean values of all groups were significantly lower (p<0.05) than those recorded on top surface. In conclusion, for the pulse-delay method, the initial exposure time can influence bond strength and Knoop hardness of composites.
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Affiliation(s)
- Eduardo Dalli'Magro
- Dental Materials Area, Department of Restorative Dentistry, Dental School of Piracicaba, State University of Campinas, Piracicaba, SP, Brazil
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da Silveira Teixeira C, Santos Felippe MC, Silva-Sousa YTC, de Sousa-Neto MD. Interfacial evaluation of experimentally weakened roots restored with adhesive materials and fibre posts: An SEM analysis. J Dent 2008; 36:672-82. [PMID: 18555579 DOI: 10.1016/j.jdent.2008.04.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Revised: 04/26/2008] [Accepted: 04/28/2008] [Indexed: 11/25/2022] Open
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Teixeira CDS, Silva-Sousa YC, Sousa-Neto MDD. Effects of light exposure time on composite resin hardness after root reinforcement using translucent fibre post. J Dent 2008; 36:520-8. [PMID: 18485559 DOI: 10.1016/j.jdent.2008.03.015] [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] [Received: 02/01/2008] [Revised: 03/24/2008] [Accepted: 03/25/2008] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES The purpose of this in vitro study was to evaluate the Vickers hardness (VHN) of a Light Core (Bisco) composite resin after root reinforcement, according to the light exposure time, region of intracanal reinforcement and lateral distance from the light-transmitting fibre post. METHODS Forty-five 17-mm long roots were used. Twenty-four hours after obturation, the root canals were emptied to a depth of 12 mm and the root dentine was artificially flared to produce a 1mm space between the fibre post and the canal walls. The roots were bulk restored with the composite resin, which was photoactivated through the post for 40s (G1, control), 80 s (G2) or 120 s (G3). Twenty-four hours after post-cementation, the specimens were sectioned transversely into three slices at depths of 2, 6 and 10mm, corresponding to the coronal, middle and apical regions of the reinforced root. Composite VHN was measured as the average of three indentations (100g/15 s) in each region at lateral distances of 50, 200 and 350 microm from the cement/post-interface. RESULTS Three-way analysis of variance (alpha=0.05) indicated that the factors time, region and distance influenced the hardness and that the interaction timexregion was statistically significant (p=0.0193). Tukey's test showed that the mean VHN values for G1 (76.37+/-8.58) and G2 (74.89+/-6.28) differed significantly from that for G3 (79.55+/-5.18). CONCLUSIONS Composite resin hardness was significantly lower in deeper regions of root reinforcement and in lateral areas distant from the post. Overall, a light exposure time of 120 s provided higher composite hardness than the shorter times (40 and 80s).
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Hammad M, Qualtrough A, Silikas N. Extended Setting Shrinkage Behavior of Endodontic Sealers. J Endod 2008; 34:90-3. [DOI: 10.1016/j.joen.2007.10.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2007] [Revised: 10/16/2007] [Accepted: 10/23/2007] [Indexed: 10/22/2022]
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