Salivary Nickel and Chromium Levels in Orthodontic Patients with and Without Periodontitis: a Preliminary Historical Cohort Study.

Many periodontal patients may need orthodontic treatment. Alterations in oral environment particularly the reduction of pH in periodontal patients could affect metal ion release from orthodontic appliances. However, there is no study on metal ion release in periodontal patients. The aim of this preliminary study was to comparatively evaluate, for the first time, salivary levels of nickel and chromium in periodontal patients (versus healthy controls) under orthodontic treatment for 2 months. In this in vivo study, 40 subjects were evaluated. Patient selection and standardization of orthodontic treatment protocols were prospectively designed and performed. Two groups of n = 20 each (control: healthy orthodontic patients, cohort: orthodontic patients with periodontitis) underwent similar protocols of fixed orthodontic treatment for 2 months. After 2 months, salivary nickel and chromium concentrations of the case and cohort groups were measured using inductively coupled plasma mass spectrometry (ICP-MS). The values were compared between the two groups using t test. There were 10 men and 10 women in each group. The mean age of patients was 34.6 ± 3.6 years old. The salivary level of nickel was 338.2 ± 235.5 ng/ml and 182.8 ± 116.5 ng/ml in the cohort and control groups, respectively (P = 0.0118). The salivary level of chromium was 7.4 ± 3.15 ng/ml in the cohort and 6.35 ± 2.39 ng/ml in the control group (P = 0.2214). Salivary level of nickel might be considerably higher in periodontal patients undergoing 2 months of orthodontic treatment compared to orthodontic patients with healthy gingivae.

Systematic review and meta-analysis of congenitally missing permanent dentition: Sex dimorphism, occurrence patterns, associated factors and biasing factors.

PURPOSE: We aimed to summarize/analyze, comprehensively and for the first time, the literature on the prevalence of congenitally missing teeth (CMT) in males and females and the CMT pattern, taking various associated and biasing factors into account. METHODS: A search was performed independently by two authors during September 2012 till June 2013 to find all the available literature regarding CMT-associated factors and patterns comprising sex dimorphism, arches, anterior/posterior regions, unilateral/bilateral patterns, and involved teeth. The data were statistically analyzed. RESULTS: Seventy-four studies were included. The mean CMT prevalence was 6.42±2.76% in males and 7.55±2.67% in females. Overall, CMT is more prevalent in females but only in epidemiological samples, and not in orthodontic or dental patients. Enrolling orthodontic/dental patients might increase the observed CMT in boys and/or reduce it in girls. Gender dimorphism was not affected by any of the factors: time, regions, or the biasing factors. There is not a significant predominance of maxillary or mandibular involvement, although the anterior segment is more likely to be affected. CONCLUSIONS: CMT is more common in girls and in the anterior segment, regardless of the date of publication. Contrary to the commonly held belief regarding more CMT prevalence in female orthodontic patients, it was shown that in dental/orthodontic patients, CMT prevalence is higher in boys.

Rate of acquired immunity in dental students after hepatitis B vaccination.

BACKGROUND: Triple-course vaccination against hepatitis B might sometimes fail to increase antibody titers or maintain it at sufficient levels. The aim of this study was to evaluate the rate of seroprotection in dental students after receiving recombinant hepatitis B vaccine. METHODS: Anti-HBs levels of 124 dental students who had received triple-course hepatitis B vaccines (scheduled at months 0, 1, and 6) were examined. Titers ≥ 100 mIU/ml were considered as protective. Associations between age, gender and duration of being vaccinated with the titer of anti-HBs were assessed. RESULTS: The participants' mean age was 24 ± 1.3 years and 93% of them were female. The time passed from receiving the final dose was 3.5 ± 1.4 years. Fifty four percent of the students had protective immune response (95% CI 45.2% to 62.8%), 24.2% had positive but weak immune response (anti-HBs titer was between 10 and 100 mIU/ml), and the rest of the subjects (21.8%) were seronegative after receiving routine HBV vaccination. CONCLUSION: There was a considerable rate of failure in achieving or maintaining acceptable titer levels following routine vaccination against HBV. Hence, determining serum anti-HBs titer after vaccination is recommended.