IADR Abstract Archives

Polymerization of Dual Cure and Phorocuring Bulk-Fill Composites

Objectives: To investigate the degree of conversion (DC%), depth of cure (DPC) and microhardness (MH) of bulk-fill composites.
Methods: Materials tested were Fill-Up! (Coltene), Tetric EvoCeram BF (Ivoclar), SDR (Dentsply), SonicFill (Kerr). Flat dentin surfaces were obtained from extracted non-carious human molars. A cylindrical mold (height: 8mm; diameter: 5mm) obtained from a putty polyvinyl-siloxane impression material was positioned on the dentin surface. After application of the adhesive system (ParaBond-Coltene), composites were placed into the mold in bulk and polymerized for 20s with a LED curing light (Coltolux SPEC3) from the top of the cylinder. After 24h molds were removed and composite cylinders were sectioned perpendicularly to the top surface to expose the composite depth. Micro-Raman spectra of the specimens were collected using a Raman equipment (Renishaw InVia) at 1mm intervals from the bottom to the composite surface. Spectra were acquired over the spectral region of 400 to 1900cm^-1. Micro-Raman spectra of the uncured and cured composites were collected to identify reference and reaction peaks [605cm^-1 (C-O-O); 1610cm^-1(aromatic ring); 1640cm^-1(C=C) group]. DC% was calculated using the ratio between reactive and internal reference peak intensities. MH assessment was measured on the same specimens analyzed with micro-Raman at 1mm intervals from the bottom to the composite surface with a Vickers microhardness tester (Leica Microsystem) at a 200g load for 10s. Data were statistically analyzed with Kruskal-Wallis and Mann-Whitney tests.
Results: Results are summarized in Table 1. Fill-Up!, Tetric EvoCeram BF and SDR showed an adequate DC% at all depths, but MH significantly decreased at higher depths for all materials except for Fill-Up!, which was the only composite with a comparable MH at all depths. SonicFill could not be polymerized beyond 6mm.
Conclusions: DC%, DPC and MH of bulk-fill composites were material-dependent. Fill-Up! was the only material showing a uniform DC%, DPC and MH at all depths.

Division: AADR/CADR Annual Meeting
Meeting: 2018 AADR/CADR Annual Meeting (Fort Lauderdale, Florida)
Location: Fort Lauderdale, Florida
Year: 2018
Final Presentation ID: 0274
Abstract Category|Abstract Category(s): Dental Materials 2:Polymer-based Materials

Authors

Cadenaro, Milena ( University of Trieste , Trieste , Italy ; IRCCS Burlo Garofolo , Trieste , Italy )

Navarra, Chiara ( University of Trieste , Trieste , Italy )

Fanfoni, Lidia ( University of Trieste , Trieste , Italy )

Mazzoni, Annalisa ( University of Bologna , Bologna , Italy )

Turco, Gianluca ( University of Trieste , Trieste , Italy )

Breschi, Lorenzo ( University of Bologna , Bologna , Italy )

Financial Interest Disclosure: NONE

SESSION INFORMATION

Poster Session
Dental Materials: Polymer-based Materials I
Thursday, 03/22/2018 , 11:00AM - 12:15PM

TABLES

Table 1. Degree of Conversion and Microhardness of the tested bulk-fill composites

DC%	Fill-Up!		SDR		SonicFill		Tetric EvoCeram BF
depth (mm)	mean	st. dev.	mean	st. dev.	mean	st. dev.	mean	st. dev.
1	59.7a	5.4	53.1a	6.8	71.9a	8.1	69.6a	4.1
2	63.7a	5.1	58.8a	4.5	67.3a	5.2	71.6a	3.0
3	62.5a	5.0	56.8a	5.5	61.8b	8.3	69.4a	4.1
4	60.3a	5.6	55.7a	5.5	54.8c	11.7	69.0a	3.9
5	61.7a	6.1	53.8a	4.9	49.2c	13.8	68.2a	3.6
6	66.4a	9.1	50.3a	10.3	40.6d	15.6	67.8a	4.2
7	59.5a	7.6	51.7a	4.0	28.0e	12.9	63.7b	4.5
8	61.5a	6.5	50.0a	4.6	n.a.	n.a.	61.0b	5.1
Microhardness	Fill-Up!		SDR		SonicFill		Tetric EvoCeram BF
depth (mm)	mean	st. dev.	mean	st. dev.	mean	st. dev.	mean	st. dev.
1	71.4A	18.5	52.6A	12.0	78.4A	6.9	64.3A	4.3
2	67.4A	19.1	47.7A	6.0	76.5A	8.8	61.1A	5.6
3	64.9A	9.4	49.7A	7.4	78.1A	11.2	63.3A	4.1
4	61.5B	8.8	46.0AB	5.3	69.7B	6.9	58.5AB	1.9
5	62.7AB	10.7	51.7A	9.6	66.0B	6.3	55.5B	3.2
6	65.4A	16.6	48.0A	7.9	56.8C	10.1	53.1B	3.3
7	66.7A	14.4	43.9B	6.7	n.a.	n.a.	49.7C	2.7
8	66.6A	14.0	42.6B	8.0	n.a.	n.a.	44.2D	4.4

DC% and MH means and standard deviations of the tested materials at all depths. Same letters indicate no statistical difference between the different depths (p>0.05) for each material (lowercase letters refer to DC%; uppercase letters refer to microhardness).