1
|
Akiya S, Sato K, Kibe K, Tichy A, Hiraishi N, Prasansuttiporn T, Hosaka K, Foxton RM, Shimada Y, Nakajima M. Polymerization shrinkage of light-cured conventional and bulk-fill composites -The effect of cavity depth and post-curing. Dent Mater J 2023. [PMID: 37032103 DOI: 10.4012/dmj.2022-210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
Abstract
Volumetric shrinkage (VS) of conventional, bulk-fill, and core build-up resin-based composites (RBCs) of various thickness (1-5 mm) was measured using the modified bonded-disk method with confocal laser scanning microscopy. Additionally, the bottom-to-top ratio of Vickers hardness (%VH) was measured. Conventional RBCs exhibited significantly higher VS than bulk-fill and core build-up RBCs (p<0.05). As specimen thickness increased, VS relative to volume (%VS) and difference in VS at each depth (VSdepth) decreased. For conventional RBCs, there was a significant drop in VSdepth between 1 mm and 2 mm (p<0.05), and another drop was observed between 3 mm and 4 mm (p<0.05) where %VH decreased below 90%. For bulk-fill and core build-up RBCs, VSdepth decreased significantly between 2 mm and 3 mm (p<0.05), but %VH exceeded 90% even in 5 mm deep cavities. These results indicated that post-curing contributed to lower shrinkage in deeper layers, and that conventional RBCs were not adequately polymerized at the depth of over 3 mm.
Collapse
Affiliation(s)
- Satoshi Akiya
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Kento Sato
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Kouta Kibe
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Antonin Tichy
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
- Institute of Dental Medicine, First Faculty of Medicine of the Charles University and General University Hospital in Prague
| | - Noriko Hiraishi
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Taweesak Prasansuttiporn
- Department of Restorative Dentistry and Periodontology, Faculty of Dentistry, Chiang Mai University
| | - Keiichi Hosaka
- Department of Regenerative Dental Medicine, Tokushima University
- Institute of Global Affairs, Tokyo Medical and Dental University
| | - Richard M Foxton
- Institute of Global Affairs, Tokyo Medical and Dental University
- Center for Dental Education, Faculty of Dentistry, Oral & Craniofacial Sciences, King's College London
| | - Yasushi Shimada
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Masatoshi Nakajima
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
- Department of Regenerative Dental Medicine, Tokushima University
| |
Collapse
|
2
|
Maucoski C, Price RB, Rocha MG, Roulet JF, Sullivan B. Ability of short exposures from laser and quad-wave curing lights to photo-cure bulk-fill resin-based composites. Dent Mater 2023; 39:275-292. [PMID: 36868892 DOI: 10.1016/j.dental.2023.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 01/10/2023] [Accepted: 01/25/2023] [Indexed: 03/05/2023]
Abstract
OBJECTIVE This study investigated the ability of a laser, and a 'quad-wave' LCU, to photo-cure paste and flowable bulk-fill resin-based composites (RBCs). METHODS Five LCUs and nine exposure conditions were used. The laser LCU (Monet) used for 1 s and 3 s, the quad-wave LCU (PinkWave) used for 3 s in the Boost and 20 s in the Standard modes, the the multi-peak LCU (Valo X) used for 5 s in the Xtra and 20 s in the Standard modes, were compared to the polywave PowerCure used in the 3 s mode and for 20 s in the Standard mode, and to the mono-peak SmartLite Pro used for 20 s. Two paste consistency bulk-fill RBCs: Filtek One Bulk Fill Shade A2 (3 M), Tetric PowerFill Shade IVA (Ivoclar Vivadent), and two flowable RBCs: Filtek Bulk Fill Flowable Shade A2 (3 M), Tetric PowerFlow Shade IVA (Ivoclar Vivadent) were photo-cured in 4-mm deep x 4-mm diameter metal molds. The light received by these specimens was measured using a spectrometer (Flame-T, Ocean Insight), and the radiant exposure delivered to the top surface of the RBCs was mapped. The immediate degree of conversion (DC) at the bottom, and the 24-hour Vickers Hardness (VH) at the top and bottom of the RBCs were measured and compared. RESULTS The irradiance received by the 4-mm diameter specimens ranged from 1035 mW/cm2 (SmartLite Pro) to 5303 mW/cm2 (Monet). The radiant exposures between 350 and 500 nm delivered to the top surface of the RBCs ranged from 5.3 J/cm2 (Monet in 1 s) to 26.4 J/cm2 (Valo X), although the PinkWave delivered 32.1 J/cm2 in 20 s 350 to 900 nm. All four RBCs achieved their maximum DC and VH values at the bottom when photo-cured for 20 s. The Monet used for 1 s and the PinkWave used for 3 s on the Boost setting delivered the lowest radiant exposures between 420 and 500 nm (5.3 J/cm2 and 3.5 J/cm2 respectively), and they produced the lowest DC and VH values. CONCLUSIONS Despite delivering a high irradiance, the short 1 or 3-s exposures delivered less energy to the RBC than 20-s exposures from LCUs that deliver> 1000 mW/cm2. There was an excellent linear correlation (r > 0.98) between the DC and the VH at the bottom. There was a logarithmic relationship between the DC and the radiant exposure (Pearson's r = 0.87-97) and between the VH and the radiant exposure (Pearson's r = 0.92-0.96) delivered in the 420-500 nm range.
Collapse
Affiliation(s)
- Cristiane Maucoski
- Department of Restorative Dentistry, State University of Ponta Grossa, Ponta Grossa, Parana, Brazil; Department of Dental Clinical Sciences, Dalhousie University, Faculty of Dentistry, Halifax, Nova Scotia, Canada
| | - Richard Bengt Price
- Department of Dental Clinical Sciences, Dalhousie University, Faculty of Dentistry, Halifax, Nova Scotia, Canada.
| | - Mateus Garcia Rocha
- Department of Restorative Dental Science, Center of Dental Biomaterials College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Jean-François Roulet
- Department of Restorative Dental Science, Center of Dental Biomaterials College of Dentistry, University of Florida, Gainesville, FL, USA
| | - Braden Sullivan
- Department of Restorative Dentistry, State University of Ponta Grossa, Ponta Grossa, Parana, Brazil
| |
Collapse
|
3
|
Furusawa K, Kobayashi S, Yamashita A, Tichy A, Hosaka K, Shimada Y, Nakajima M. Effect of filler load on structural coloration and color adjustment potential of resin composites. Dent Mater J 2023. [PMID: 36709985 DOI: 10.4012/dmj.2022-199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The color-matching ability of single-shade composites Omnichroma (OMN) and Omnichroma Flow (OCF) is ensured by structural color, which arises from monodisperse 260 nm spherical fillers. This study evaluated how filler load influences the color adjustment potential of composite restorations to human teeth of various shades. The performance of composites containing the 260 nm spherical fillers -OMN (79 wt%), OCF (71 wt%), and experimental composites R1 (65 wt%), and R2 (60 wt%)- was compared to two conventional A2-shade composites and a transparent composite. Additionally, the translucency parameter, spectral reflectance, and light transmission properties were assessed. Composites with a lower load of the 260 nm spherical fillers exhibited lower light diffusion and lower reflectance in the yellow-to-red range (580-650 nm), which is characteristic for the structural color of OMN and OCF. The best color adjustment was achieved with OCF, presumably due to its high translucency and uniform spectral reflectance.
Collapse
Affiliation(s)
- Kiyoka Furusawa
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Shun Kobayashi
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Ako Yamashita
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Antonin Tichy
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.,Institute of Dental Medicine, First Faculty of Medicine of the Charles University and General University Hospital in Prague
| | - Keiichi Hosaka
- Department of Regenerative Dental Medicine, Tokushima University
| | - Yasushi Shimada
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University
| | - Masatoshi Nakajima
- Department of Cariology and Operative Dentistry, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.,Department of Regenerative Dental Medicine, Tokushima University
| |
Collapse
|
4
|
Labrie D, Price RB, Sullivan B, Salazar AM, Gautam D, Stansbury JW, Ferracane JL. Effect of thickness on the degree of conversion of two bulk-fill and one conventional posterior resin-based composites at high irradiance and high temporal resolution. J Mech Behav Biomed Mater 2022; 136:105489. [PMID: 36206689 DOI: 10.1016/j.jmbbm.2022.105489] [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: 07/25/2022] [Revised: 09/22/2022] [Accepted: 09/24/2022] [Indexed: 11/30/2022]
Abstract
OBJECTIVES This study: 1) measures the effect of sample thickness and high irradiance on the depth-dependent time delay before photopolymerization reaction onset; 2) determines if exposure reciprocity exists; 3) measures the conversion rate at four irradiance levels; 4) determines the time, t0, at which the maximum DC rate is reached for two bulk-fill and one conventional posterior resin-based composites (RBCs). METHODS Tetric PowerFill IVA shade (Ivoclar Vivadent) and Aura bulk-fill ultra universal restorative (SDI), and one conventional posterior resin-based composite (RBC), Heliomolar A3 (Ivoclar Vivadent), that were either 0.2 mm, 2 mm, or 4 mm thick were photocured using a modified Bluephase G4 (Ivoclar Vivadent) light-curing unit (LCU) that delivered a single emission band (wavelength centered at 449 nm). The same radiant exposure of 24 J/cm2 was delivered at irradiances ranging from 0.5 to 3 W/cm2 by adjusting the exposure time. PowerFill was also photocured for 3 s or 6 s using a Bluephase PowerCure LCU (Ivoclar Vivadent) on the 3 s mode setting. The degree of conversion (DC) was measured in real-time at a high temporal resolution at 30 °C using Attenuated Total Reflection (ATR) FTIR spectroscopy with a sampling rate of 13 DC data points per second. The DC data were analyzed using a phenomenological autocatalytic model. The RBC viscosity was measured at 21 °C and 30 °C. Light transmission through the RBC samples at 22 °C was monitored with time to calculate the extinction coefficients of the RBCs. RESULTS The time delay before photopolymerization started increased as the RBC thickness increased and the irradiance decreased. An autocatalytic model described the DC data. The time t0 was less than 77 ms for the 0.2 mm thick samples of PowerFill irradiated using the highest irradiance of 3 W/cm2. Among the three RBCs for each sample thickness and irradiance level, the PowerFill had the smallest time t0. There was a time delay of 0.59 s and 1.25 s before the DC started to increase at the bottom of 4 mm thick samples for the PowerFill and Aura, respectively, when an irradiance of 1 W/cm2 was delivered. The time delay increased to 3.65 s for the Aura when an irradiance of 0.5 W/cm2 was delivered. The extinction coefficients near 449 nm were 0.78 mm-1, 0.76 mm-1, and 1.55 mm-1 during the first 2 s after the start of photocuring of PowerFill, Aura, and Heliomolar, respectively. Only PowerFill followed exposure reciprocity. At T = 30 °C, the viscosity was 3400, 17000, and 5200 Paˑs for PowerFill, Aura, and Heliomolar, respectively. SIGNIFICANCE The time delay between when photopolymerization starts at the top and bottom of 2- or 4-mm thick RBC restorations may affect the structural integrity of the bond between the tooth and the bottom of the restoration. Only PowerFill followed exposure reciprocity between irradiance levels of 0.5 to 3 W/cm2. Exposure reciprocity did not occur for Aura or Heliomolar, neither of which are optimized for short light exposure or high irradiance conditions.
Collapse
Affiliation(s)
- Daniel Labrie
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada.
| | - Richard B Price
- Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Braden Sullivan
- Department of Dental Clinical Sciences, Dalhousie University, Halifax, Nova Scotia, B3H 4R2, Canada
| | - Austyn M Salazar
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309-0596, United States
| | - Dixa Gautam
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309-0596, United States
| | - Jeffrey W Stansbury
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309-0596, United States; Department of Craniofacial Biology, School of Dental Medicine, University of Colorado, Anschutz Medical Campus, Aurora, CO, 80045, United States
| | - Jack L Ferracane
- Department of Restorative Dentistry, Oregon Health & Science University, Portland, OR, United States
| |
Collapse
|
5
|
Bisphenol A Release from Dental Composites and Resin-Modified Glass Ionomers under Two Polymerization Conditions. Polymers (Basel) 2021; 14:polym14010046. [PMID: 35012066 PMCID: PMC8747459 DOI: 10.3390/polym14010046] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/19/2021] [Accepted: 12/21/2021] [Indexed: 01/12/2023] Open
Abstract
Bisphenol A (BPA)-based monomers are commonly contained in dental resin-based materials. As BPA is an endocrine disruptor, its long-term release from restorative composites and resin-modified glass ionomers (RM-GICs) under two polymerization conditions was measured in this study. Specimens of two conventional composites containing BPA-based monomers, two “BPA-free” composites, and two RM-GICs were polymerized from one side for 20 s at 1300 mW/cm2 or for 5 s at 3000 mW/cm2. The amounts of BPA released in artificial saliva and methanol after 1, 4, 9, 16, 35, 65, 130, and 260 days were measured using liquid chromatography–tandem mass spectrometry. The highest amounts of BPA were released from conventional composites, followed by RM-GICs, while the least was released from “BPA-free” composites. Amounts of released BPA were significantly higher in methanol and decreased gradually after the first day. Fast polymerization (5 s at 3000 mW/cm2) resulted in a significantly higher release of BPA after 1 day, but the effect of polymerization conditions was not significant overall. In conclusion, fast polymerization increased the initial release of BPA, but the released amounts were significantly lower than the current tolerable daily intake (4 μg/kg body weight/day) even in methanol, representing the worst-case scenario of BPA release.
Collapse
|