OBJECTIVE: Traditional retainers (both metal and fiber-reinforced composite [FRC]) have limitations, and a retainer made from more flexible ligature wires might be advantageous. We aimed to compare an experimental design with two traditional retainers. METHODS: In this prospective preliminary clinical trial, 150 post-treatment patients were enrolled and randomly divided into three groups of 50 patients each to receive mandibular canine-to-canine retainers made of FRC, flexible spiral wire (FSW), and twisted wire (TW). The patients were monitored monthly. The time at which the first signs of breakage/debonding were detected was recorded. The success rates of the retainers were compared using chi-squared, Kaplan-Meier, and Cox proportional-hazard regression analyses (α = 0.05). RESULTS: In total, 42 patients in the FRC group, 41 in the FSW group, and 45 in the TW group completed the study. The 2-year failure rates were 35.7% in the FRC group, 26.8% in the FSW group, and 17.8% in the TW group. These rates differed insignificantly (chi-squared p = 0.167). According to the Kaplan-Meier analysis, failure occurred at 19.95 months in the FRC group, 21.37 months in the FSW group, and 22.36 months in the TW group. The differences between the survival rates in the three groups were not significant (Cox regression p = 0.146). CONCLUSIONS: Although the failure rate of the experimental retainer was two times lower than that of the FRC retainer, the difference was not statistically significant. The experimental TW retainer was successful, and larger studies are warranted to verify these results.
Humans ; Kaplan-Meier Estimate ; Ligation ; Prospective Studies ; Research Design ; Survival Analysis* ; Survival Rate

Objective: Recent studies have shown a possible association between vitamin D deficiency and the severity of primary dysmenorrhea. The present study aimed to investigate the effect of vitamin D supplementation on pain and systemic symptoms in patients with primary dysmenorrhea. Methods: This double-blind, randomized, placebo-controlled trial was conducted on female students aged 18 to 32 years with primary dysmenorrhea and vitamin D deficiency (25 [OH]D <30 ng/mL). The participants (n=116) received either 50,000 IU of vitamin D3 (cholecalciferol) or placebo capsules on a weekly basis for eight consecutive weeks. The outcomes were pain intensity (scored 0 to 10), number of days with pain, number of consumed pain-relief medications (per day), and severity of systemic symptoms (fatigue, headache, nausea/vomiting, and diarrhea; total score of 0 to 12). Results: Compared with baseline, our participants who received vitamin D experienced significant reductions in pain intensity (-1.0 and -1.5 score at weeks 4 and 8, P<0.001), the number of days with pain (-1.0 day at weeks 4 and 8, P<0.001), the number of consumed pain-relief medications (-1.0 at weeks 4 and 8, P<0.001), and systemic symptoms severity (-1.0 score at weeks 4 and 8, P<0.001). No significant improvements were observed in the placebo group in terms of these outcomes. Conclusion Vitamin D supplementation in women with primary dysmenorrhea and vitamin D deficiency could improve systemic symptoms and reduce pain intensity, the number of days with pain, and the need for consuming pain-relief medications.

Objective: Recent studies have shown a possible association between vitamin D deficiency and the severity of primary dysmenorrhea. The present study aimed to investigate the effect of vitamin D supplementation on pain and systemic symptoms in patients with primary dysmenorrhea. Methods: This double-blind, randomized, placebo-controlled trial was conducted on female students aged 18 to 32 years with primary dysmenorrhea and vitamin D deficiency (25 [OH]D <30 ng/mL). The participants (n=116) received either 50,000 IU of vitamin D3 (cholecalciferol) or placebo capsules on a weekly basis for eight consecutive weeks. The outcomes were pain intensity (scored 0 to 10), number of days with pain, number of consumed pain-relief medications (per day), and severity of systemic symptoms (fatigue, headache, nausea/vomiting, and diarrhea; total score of 0 to 12). Results: Compared with baseline, our participants who received vitamin D experienced significant reductions in pain intensity (-1.0 and -1.5 score at weeks 4 and 8, P<0.001), the number of days with pain (-1.0 day at weeks 4 and 8, P<0.001), the number of consumed pain-relief medications (-1.0 at weeks 4 and 8, P<0.001), and systemic symptoms severity (-1.0 score at weeks 4 and 8, P<0.001). No significant improvements were observed in the placebo group in terms of these outcomes. Conclusion Vitamin D supplementation in women with primary dysmenorrhea and vitamin D deficiency could improve systemic symptoms and reduce pain intensity, the number of days with pain, and the need for consuming pain-relief medications.