Shear Bond Strength of Bulk-Fill Composites to Resin-Modified Glass Ionomer Evaluated by Different Adhesion Protocols

Figures & data

Table 1 List of Materials Used in the Study

Material	Company	Composition
Restorative materials
GC Fuji II LC^® resin-reinforced glass ionomer, shades A1, A3	GC Corp., Tokyo, Japan	2-hydroxyethyl methacrylate (HEMA) 25–50% Polybasic carboxylic acid 5–10% Urethane dimethacrylate (UDMA) 1–5% Dimethacrylate 1–5%
Filtek^TM One Bulk Fill posterior composite [FOBF], shade A2	3M ESPE, St. Paul, MN, USA	AFM (dynamic stress-relieving monomer), AUDMA, UDMA and 1, 12-dodecane-DMA Fillers: a combination of a non-agglomerated/non-aggregated 20-nm silica filler, a non-agglomerated/non-aggregated 4- to 11-nm zirconia filler, an aggregated zirconia/silica cluster filler (comprised of 20-nm silica and 4- to 11-nm zirconia particles) and a ytterbium trifluoride filler consisting of agglomerate 100-nm particles. Inorganic filler: 76.5% by weight (58.5% by volume).
Tetric^®N-Ceram Bulk Fill composite [TNCBF], shade A2	Ivoclar Vivadent AG, Schaan, Liechtenstein	Bis-GMA, Bis-EMA and UDMA, light initiator (Ivocerin^®) Fillers: Barium aluminum silicate glass with two different mean particle sizes; isofillers comprised of cured dimethacrylates, ytterbium fluoride, and spherical mixed oxide. Inorganic filler: 75% by weight, (61% by volume) and 17% polymer fillers or Isofillers.
Filtek^TM Z350 XT composite [Z350XT], shade A2	3M ESPE, St. Paul, MN, USA	Bis-GMA, UDMA, TEGDMA, PEGDMA, bis-EMA(6) resins. Fillers: Average cluster particle size of 0.6 to 10 microns, non-agglomerated/non-aggregated 20-nm silica filler, non-agglomerated/non-aggregated 4- to 11-nm zirconia filler, and aggregated zirconia/silica cluster filler. Inorganic fillers: 78.5% by weight (63.3% by volume).
Adhesive systems
OptiBond™ Solo Plus [OB] total-etch adhesive system	Kerr Dental, Orange, CA, USA	Ethyl alcohol: 20–25% Alkyl dimethacrylate resins: 55–60% Barium aluminoborosilicate glass: 5–10% Fumed silica (silicon dioxide): 5–10% Sodium hexafluorosilicate: 0.5–1%
CLEAR FIL SE BOND2 [CFSE] self-etch adhesive system	Kuraray Corp., Tokyo, Japan	Primer: 10-MDP, HEMA, hydrophilic dimethacrylate, photo-initiator, water. Bond: HEMA, 10-MDP, Bis-GMA, hydrophobic dimethacrylate, initiator, accelerator, silanated colloidal silica.
3M^TM Single Bond Universal [SBU] adhesive system	3M ESPE, St. Paul, MN, USA	MDP phosphate monomer, HEMA, ethanol, Vitrebond copolymer, filler, water, initiators, dimethacrylate resins, silane.

Table 2 Mean Values of Shear Bond Strength for the Resin-Based Composite Materials Within Each Adhesion Protocol Group

Adhesion Protocol	Type of Composite Material Mean Values of SBS (SD) in MPa
	FOBF	TNCBF	Z350XT
NT	5.05 (0.69)^aA	5.58 (0.60)^aA	6.41 (049)^bA
OB	13.79 (0.72)^aB	14.30 (1.08)^aB	10.27 (0.60)^bB
CFSE	13.48 (0.48)^aB	14.06 (1.03)^aBC	12.09 (1.07)^bC
SBU-TE	11.79 (0.99)^aC	13.05 (0.53)^bC	12.07 (0.52)^aC
SBU-SE	13.88 (0.66)^aB	14.20 (1.03)^abBC	12.72 (1.02)^acC

Notes: Different lower-case superscript letters, in the same row, indicate statistically significant differences between composite materials within each adhesion protocol group (P<0.05). Different upper-case superscript letters, in the same column, indicate statistically significant differences between adhesion protocols within each composite resin material group (P<0.05).

Abbreviations: SBS, shear bond strength; SD, standard deviation; FOBF, Filtek One Bulk Fill; TNCBF, Tetric-N Ceram Bulk Fill; Z350XT, Filtek Z350 XT; NT, no treatment; OB, OptiBond Solo Plus; CFSE, Clear Fil SE Bond 2; SBU-TE, Single Bond Universal in total-etch mode; SBU-SE, Single Bond Universal in self-etch mode.

Figure 1 Bar chart representing mean values of shear bond strength for the adhesion protocol groups compared with the cohesive control group. * Statistically significant compared with the cohesive group (P<0.05).

Abbreviations: SBS, shear bond strength; FOBF, Filtek One Bulk Fill; TNCBF, Tetric-N Ceram Bulk Fill; Z350XT, Filtek Z350 XT; NT, no treatment; OB, OptiBond Solo Plus total-etch system; CFSE, Clear Fil SE Bond 2 self-etch system; SBU-TE, single bond universal in total-etch mode; SBU-SE, single bond universal in total-etch mode.

Figure 2 Stacked bar chart that displays the distribution of modes of failure in adhesion protocol groups.

Abbreviations: FOBF, Filtek One Bulk Fill; TNCBF, Tetric-N Ceram Bulk Fill; Z350XT, Filtek Z350 XT; NT, no treatment; OB, OptiBond Solo Plus total-etch system; CFSE, Clear Fil SE Bond 2 self-etch system; SBU-TE, single bond universal in total-etch mode; SBU-SE, single bond universal in total-etch mode.