Impact of adhesive application errors on dentin bond strength of resin composite

Figures & data

Table 1. Pre-treatment of dentin specimens (n = 15/group).

OptiBond FL
		Time:			Time:			Time:			Time:
Group 1 (control)	Phosphoric acid 37%	15 s	Group 2	Phosphoric acid 37%	15 s	Group 3	Phosphoric acid 37%	15 s	Group 4	Phosphoric acid 37%	15 s
	Water-spray	15 s		Water-spray	15 s		Water-spray	15 s		Water-spray	15 s
	Air-dry	3 s		Air-dry	3 s		Air-dry	3 s		Air-dry	3 s
	OptiBond FL primer	15 s		OptiBond FL adhesive	–		OptiBond FL primer	15 s		OptiBond FL primer	15 s
	Air	3 s		Light-cure	20 s		OptiBond FL adhesive	–		Air	3 s
	OptiBond FL adhesive	–					Light-cure	20 s		Light-cure	20 s
	Light-cure	20 s
Clearfil SE
		Time:			Time:			Time:			Time:
Group 1 (control)	Clearfil SE Bond primer	–	Group 2	Clearfil SE Bond bond	–	Group 3	Clearfil SE Bond primer	–	Group 4	Clearfil SE Bond primer	–
	Waiting time	20 s		Air	3 s		Waiting time	20 s		Waiting time	20 s
	Air	3 s		Light-cure	20 s		Clearfil SE Bond bond	–		Air	3 s
	Clearfil SE Bond bond	–					Air	3 s		Light-cure	20 s
	Air	3 s					Light-cure	20 s
	Light-cure	20 s
Scotchbond Universal
		Time:			Time:			Time:
Group 1 (control)	Scotchbond Universal	20 s	Group 2	Scotchbond Universal	20 s	Group 3	Scotchbond Universal	20 s
	Air	3 s		Light-cure	20 s		Air	3 s
	Light-cure	20 s

Table 2. Materials used.

Material	Composition according to the manufacturer	Manufacturer
Filtek Z250 (Lot: N783261)	Bis-GMA, UDMA, Bis-EMA, TEGDMA, zirconium/silica nonagglomerated particles	3M ESPE, St. Paul, MN, USA
OptiBond FL primer (Lot 7096704), adhesive (Lot 6921581)	primer: HEMA, GPDM, PAMM, ethanol, water, photoinitiator adhesive: TEGDMA, UDMA, GPDM, HEMA, Bis-GMA, filler, photoinitiator	Kerr, Orange, CA, USA
Clearfill SE primer (Lot 1E0348), bond (Lot 170616)	primer: MDP, HEMA, hydrophilic dimethacrylate, photoinitiator, water bond: MDP, Bis-GMA, HEMA, hydro- philic dimethacrylate, microfiller	Kuraray, Osaka, Japan
Scotchbond Universal (Lot 00729A)	MDP, Dimethacrylate resins, HEMA, Vitrebond™ Copolymer, filler, ethanol, water, initiators, silane	3M ESPE, St. Paul, MN, USA

Bis-EMA: Bisphenol-A polyethylenglycol dietherdimethacrylate; Bis-GMA: Bisphenol-A glycidylmethacrylate; GPDM: Glycerol phosphate dimethacrylate; HEMA: Hydroxyethylmethacrylate; MDP: 10-Methacryloyloxydecyl dihydrogen phosphate; METP: Methacryloyloxyethyl acid phosphate; PAMM: Phthalic acid monoethyl methacrylate; TEGDMA: Triethylene glycol dimethacrylate; UDMA: Urethane dimethacrylate.

Figure 1. (a–d) Boxplots of the shear bond strength results (The horizontal line within each box represents the median value, the lower line represents the 1st quartile, and the top line represents the 3rd quartile. The whiskers extend vertically to within 1.5 of the IQR (= the distance between the first and the third quartiles). Same letters indicate no significant differences; different letters indicate significant differences between the SBS values.) CSE = Clearfil SE, OFL = OptiBond FL, SBU = Scotchbond Universal.

Figure 2. (a-c) Failure mode 1: Cohesive in dentin; Failure mode 2: Adhesive at the dentin surface; Failure mode 3: Adhesive between adhesive system and resin composite; Failure mode 4: Cohesive in resin composite; Failure mode 5: Mixed (mixed type fracture pattern 1) to 4)).

Table 3. Shear bond strength results (mean values and standard deviations; MPa).

OptiBond FL
Groups	Mean	Standard deviation
1 (Control)	17.1^A	4.4
2 (No primer)	7.0^C	4.4
3 (No evaporation of primer)	11.3^B	2.7
4 (No adhesive)	15.7^A	4.0
Clearfil SE
Groups	Mean	Standard deviation
1 (Control)	12.1^a	5.1
2 (No primer)	5.3^b	1.3
3 (No evaporation of primer)	5.7^b	2.0
4 (No bond)	1.6^c	1.3
Scotchbond Universal
Groups	Mean	Standard deviation
1 (Control)	18.0^A	4.6
2 (No evaporation)	7.3^B	3.1
3 (No light-cure)	11.5^C	4.8
Control groups
Groups	Mean	Standard deviation
OptiBond FL	17.1^A	4.4
Clearfil SE	12.1^B	5.1
Scotchbond Universal	18.0^A	4.6

For each of the four groups of comparison (OptiBond FL, Clearfil SE, Scotchbond Universal, Control groups), same letters indicate no significant difference, different letters indicate significant difference between groups. Capital letters = results analysed with parametric tests; lower case letters = results analysed with non-parametric tests.