Synergic effect of salivary pH baselines and low pH intakes on the force relaxation of orthodontic latex elastics

Abstract

Background: Latex elastics are still in common use due to their low cost and high flexibility to
improve sagittal discrepancies or interdigitation of teeth. Mechanical properties of elastics are
influenced by several environmental factors such as pH changes. This study evaluated similar latex
elastics to define the influence of synergic effect of intermittent low pH and various baselines pH
of saliva.
Materials and Methods: Four groups of latex elastics (3‑M Unitek, 3/16 inch) were tested (n = 15
in each group). Two groups of elastics were immersed in two tanks of artificial saliva with different
pH levels of 7 and 5, and two groups were immersed in two tanks of artificial saliva with intermittent
drop of pH to 4. The force was measured when the elastics were stretched to 25 mm. These
measurements were taken in 0, 4, 8, 12, 24, 36, and 48 h for each group. Repeated measures analysis
of variance (RMANOVA) and post‑hoc Tukey’s test were used to assess the findings. The level of
significance was 0.05%.
Results: The interaction between pH and time analyzed with RMANOVA showed no significant
differences (P > 0.05) except in 36 h (P = 0.014). The Tukey’s analysis showed that each comparison
between any two groups did not indicate significant differences (P > 0.05) except between Groups 1
and 3 and between Groups 2 and 3 (P < 0.05).
Conclusions: No significant correlation was seen between fluctuation of pH and force degradation
in latex elastic band except in 36 h.

Key Words:Orthodontic Appliances,It should be deleted.latex, orthodontic