Page 7 - SPEMD_60-4

Revista Portuguesa de Estomatologia,
Medicina Dentária e Cirurgia Maxilofacial

rev port estomatol med dent cir maxilofac. 2019;60(4):155-162

Original research

Surface properties after chemical aging of
chlorhexidine delivery systems based on acrylic resin

c
a
a
a
b
Joana Costa , Ana Bettencourt , Ana Madeira , Luís Nepomuceno , Jaime Portugal ,
c,
Cristina Bettencourt Neves *
a Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal
b Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Lisbon, Portugal
c Oral and Biomedical Sciences Research Unit (UICOB), Faculdade de Medicina Dentária, Universidade de Lisboa, Lisbon, Portugal

a r t i c l e i n f o a b s t r a c t
Article history: Objectives: To evaluate the effect of chlorhexidine incorporation on the surface free energy
Received 13 August 2019 and microtensile bond strength of three reline acrylic resins, after chemical aging.
Accepted 5 November 2019 Methods: For each of the studies, six experimental groups were set according to reline resin
Available online 20 December 2019 and chlorhexidine incorporation [Kooliner – 0% vs. 2.5% chlorhexidine; Ufi Gel Hard and
Probase Cold – 0% vs. 5% chlorhexidine]. The specimens were submitted to a chemical aging
Keywords: process for 4 weeks (pH fluctuation in artificial saliva, cycles of 6 hours at pH=3 and 18 hours
Acrylic resins at pH=7). For the first study, 42 specimens were prepared (n=7) and, after chemical aging, the
Chlorhexidine surface free energy was calculated. For the adhesive strength study, 36 denture base resin
Denture stomatitis cubes were prepared and reline resin was applied to them according to the experimental
Surface tension group (n=6). Five sticks (1×1 mm section) were obtained from each specimen and submitted
Tensile strength to chemical aging followed by microtensile test (1 kN; 1 mm/min). Data were analyzed with
Kruskal-Wallis and Mann-Whitney non-parametric tests (α=0.05).
Results: Differences (p<0.05) were observed between resins, both in surface energy and in
bond strength. The chlorhexidine incorporation did not affect the surface energy of neither
of the resins and also did not affect the bond strength of Kooliner and Ufi Gel Hard (p>0.05).
Incorporating 5% chlorhexidine (p=0.004) decreased the Probase Cold bond strength to the
denture base resin.
Conclusions: After chemical aging, chlorhexidine incorporation only negatively affected the
bond strength of Probase Cold. (Rev Port Estomatol Med Dent Cir Maxilofac. 2019;60(4):155-162)
© 2019 Sociedade Portuguesa de Estomatologia e Medicina Dentária.
Published by SPEMD. This is an open access article under the CC BY-NC-ND license
(http://creativecommons.org/licenses/by-nc-nd/4.0/).

* Corresponding author.
E-mail address: cristina.neves@fmd.ulisboa.pt (Cristina Bettencourt Neves).
http://doi.org/10.24873/j.rpemd.2019.12.688
1646-2890/© 2019 Sociedade Portuguesa de Estomatologia e Medicina Dentária. Published by SPEMD.
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).