Changes in Salivary pH under the Effect of Stainless Steel versus Elastomeric Ligatures in a Selected Group of Orthodontic Patients: A Randomized Clinical Trial

Abstract

Enamel demineralization is a complication of fixed orthodontic treatment. Fluctuations in pH of saliva during prolonged treatment course influence demineralization. This prospective randomized clinical trial aimed to evaluate and compare the short-term effect of stainless steel and elastomeric modules on salivary pH in patients under treatment with fixed orthodontic appliances. Whole unstimulated (resting) salivary samples were collected from 62 participants (12 males and 50 females) aged 15–40 years who met specific inclusion criteria. They were randomly allocated into two groups through computer-generated randomization before tying of ligatures at T0 (baseline), 2 weeks, 6 weeks and 12 weeks after. Each group included 31 subjects. Two commonly used archwire ligatures (stainless steel and elastomeric; SIA, Italy) were tested. Salivary pH was measured using a digital pH meter (3510, JENWAY, UK). Blinding of patients and clinicians to the intervention was impossible; blinding was applied only for outcome assessment and the statistician. Eight participants did not receive the allocated intervention for various reasons. After 6 weeks (T2) and 12 weeks (T3) from baseline, a significant decrease in salivary pH was observed (p < 0.05) in the elastomeric group compared with the stainless-steel group. The study concluded that the two archwire ligatures showed a significant difference in salivary pH during early orthodontic treatment. Elastomeric modules significantly lowered pH to an unfavorable level that may increase the risk of enamel demineralization.