Esthetic restorative materials and glass ionomer cements: Influence of acidic drink exposure on bacterial adhesion

Objective:
The purpose of this research was to evaluate and compare bacterial adhesion on five esthetic restorative materials, three
glass ionomer cements (GIC), and two GIC with coat. All the materials were considered after acidic drink exposure.
Materials and
Methods:
Thirty cylindrical sample of each of the 10 materials were prepared and then divided into three groups: group 1 (baseline),
Group 2 (1 day in acidic soft drink), and Group
3 (7
days in acidic soft drink). Bacterial suspension of
Streptococcus
mutans
was cultured and deposited onto each material, and the adhesion was evaluated through the colony‑forming units determination.
One‑way ANOVA and Bonferroni’s
post
hoc
tests were applied to estimate significant differences between the esthetic materials.
Results:
The highest amount of
S.
mutans
was recorded in Group
3 and the lowest in Group 1 (baseline). In general, the GIC
showed bacterial adhesion values higher than the ones related to composites both in Group 2 than in Group 3. Acidic soft drinks
lead a time‑dependent degradation of restorative materials causing an increase of the surface
rugosity.
In fact, a general increase
in
S.
mutans
cells adhesion to treated samples was observed.
Conclusions:
The use of acidic soft drink resulted in a degradation
of the surface layer of the restorative material with consequent increase of bacterial adhesion. The GIC can be considered a more
friendly environment for bacterial adhesion. This is true in particular if acid substances have already deteriorated the surface.