Interference of the assessment method in pH values of an epoxy-based cement

Resumo

Alkalinization potential is a fundamental property
of endodontic epoxy-based cements containing calcium hydroxide.
Studies have shown discrepant pH results for same materials at
different evaluation periods. A possible reason accounting for these
differences may be the assessment procedures. Objective: To evaluate
the pH value of an epoxy-based cement (Sealer 26) in different periods
of analysis, using two assessment methods. Material and methods:
Sealer 26 was manipulated and immediately placed into polyethylene
tubes (n=10, each group) and immersed in distilled water. In G1, the
tubes were kept in the same water during all experiment; and in G2,
the tubes were removed and placed into another flask with an equal
amount of water after the pH evaluation. The pH of these solutions was
measured at 24 hours, 7, 14 and 28 days. Analysis were made within
the same group according to the experimental periods and between
groups in each experimental period. Data were submitted to ANOVA
(α = 5%) and t test, respectively. Results: For G1 and G2, all periods showed different pH values (p < 0.05), except between 14 and 28
days (p > 0.05) and between 7 and 14 days (p > 0.05), respectively.
In each period, no significant differences were observed between
the groups. Conclusion: The method to obtain the pH values in
different experimental periods no interfered in the final results.
However, difference was observed when the results were analyzed
at same group.