Effect of a desensitizing dentifrice on the bond strength of different adhesive systems|
Nóbrega Cavalcanti, Andrea; Santos de Souza, Evangelista; dos Santos Lopes, Gabriela; Pinheiro de Freitas, Anderson; de Araújo, Roberto Paulo Correia & Mathias, Paula
Aim: This in vitro study evaluated the effect of using a dental hypersensitivity treatment on the
bond strength to dentin of etch-and-rinse and self-etching simplified adhesive systems.
40 healthy molars were used. The crowns of teeth were removed at the dentinoenamel junction,
and remaining roots were sectioned in the mesiodistal direction along their long axis, separating
the buccal and lingual/palatal halves. The segments obtained were ground, keeping the buccal
or lingual/palatal face turned downwards in order to flatten the surface and produce a standardized
smear layer. Prepared specimens were randomly distributed into 4 groups (n=10), according to
the combination of surface treatment with the desensitizing dentifrice Colgate Sensitive Pro-Relief
(Colgate Palmolive®) (test group - with dentifrice and control group - without dentifrice) and type
of simplified bonding agent (etch-and-rinse and self-etching agents). Resin composite blocks
were fabricated on the dentin surfaces, after application of bonding agents, and specimens were
sectioned into rectangular stick-shaped specimens with cross-sectional area of approximately
0.8mm2. For microtensile bond strength tests, 4 sticks were randomly selected from the central
region of specimens, and fixed to a universal test machine. Data were analyzed statistically by the
Mann-Whitney U test (a=0.05).
Results: The bond strength obtained in the group without
desensitizer (control) + etch-and-rinse agent was significantly higher compared with the other
groups. Under both experimental conditions, the self-etching agent showed weak bond strength
Conclusions: Change in the dentin substrate by obliteration of tubules in the process
of relieving dentinal sensitivity could reduce the bond strength of simplified etch-and-rinse and
self-etching bonding agents.
dentin, dentin sensitivity, adhesive systems