Universal cements: dual activated and chemically activated

Figures & data

Table 1. Cements used, manufacturers and chemical composition.

Products	Manufacturer	Product composition
RelyX Ultimate Clicker	3M ESPE, St. Paul, MN	Base: methacrylate monomers; Radiopaque; salinized fillings; initiator and stabilizer components; rheological additives. Catalyst: methacrylate monomers; alkaline radiopaque; initiator and stabilizer components; pigments; fluorescent dyes; rheological additives, cure in the dark; activator of the Scotchbond Universal adhesive.
Duo-Link	Bisco	Base: Bis-GMA; Triethylene glycol dimethacrylate; urethane dimethacrylate; fill the glass; catalyst; Bis-GMA. Triethylene glycol dimethacrylate; fiberglass.
Nexus 3	Kerr, Australia Pty. Ltd.	The manufacturer did not specify the composition.
RelyX ARC	3M/ESPE St. Paul, MN	Paste A: TEGDMA, Bis-GMA, zirconia silica, pigments, amine and a photoinitiator system. Paste B: Bis-GMA, TEGDMA, zirconia silica, benzoyl peroxide.

Table 2. Application according to the manufacturer’s instructions in the photoactivated groups.

Cement	Form of application
RelyX Ultimate Clicker Universal	After the application of the self-etching adhesive system Adper Scotchbond Universal (3M/ESPE), mix the paste base and the catalyst base until obtaining a homogenous paste in 20 s using a spatula. Apply to all cavity walls, position and stabilize the indirect restoration and photoactivate each face of the restoration for 20 s.
Duo-Link Universal	Apply the self-etching adhesive system All Bond. Mix the two pastes, applying directly in the preparation, position the indirect restoration by holding it firmly in place for between 20 and 30 s, remove the excess and photoactivate for 40 s.
Nexus 3 Universal	After the application of the self-etching adhesive system OptiBond All In One, apply the cement and remove the excess and photoactivate for 40 s.
RelyX ARC Conventional	After acid conditioning and the use of the adhesive system (Adper Single Bond), dispense equal proportions of cement on a disposable mixing block, mix with a spatula for 10 s, apply to the cavity and wait 5 min. Then, photoactivate for 40 s.

Table 3. Means (standard deviations) of tensile bond strength (MPa) according to the cementing agent and the activation technique.

Cementing agents	Photoactivated (DA)	Chemically activated (CA)
Duo Link Universal	11.67 ± 2.82	8.49 ± 2.18^a	p^1 = .011*
RelyX Ultimate	10.15 ± 3.20	1.43 ± 0.34^b	p^(1) < .001*
Nexus 3	10.50 ± 2.13	6.86 ± 1.27^a	p^(1) < .001*
Rely ARC	10.56 ± 4.29	7.14 ± 2.64^a	p^(1) = .046*

p = .517 p = .001*.

^a,bDifferent letters in the same column indicate statistically significant differences between the cements and by group – DA or CA – (p < .05). *Indicates a significant difference between the activation techniques per cement.