Do soft drinks affect metal ions release from orthodontic appliances?

Metal leakage from orthodontic appliances chemically alters enamel surface during experimental in vitro simulated treatment

Human enamel is composed mainly of apatite. This mineral of sorption properties is susceptible to chemical changes, which in turn affect its resistance to dissolution. This study aimed to investigate whether metal leakage from orthodontic appliances chemically alters the enamel surface during an in vitro simulated orthodontic treatment. Totally 107 human enamel samples were subjected to the simulation involving metal appliances and cyclic pH fluctuations over a period of 12 months in four complimentary experiments. The average concentrations and distribution of Fe, Cr, Ni, Ti and Cu within the enamel before and after the experiments were examined using ICP‒MS and LA‒ICP‒MS techniques. The samples exposed to the interaction with metal appliances exhibited a significant increase in average Fe, Cr and Ni (Kruskal-Wallis, p < 0.002) content in comparison to the control group. The outer layer, narrow fissures and points of contact with the metal components showed increased concentrations of Fe, Ti, Ni and Cr after simulated treatment, conversely to the enamel sealed with an adhesive system. It has been concluded that metal leakage from orthodontic appliances chemically alters enamel surface and microlesions during experimental in vitro simulated treatment.

Determination of metal ions release from orthodontic archwires in artificial saliva using inductively coupled plasma-optical emission spectrometer (ICP-OES)

Over the last decades many concerns have been raised regarding the migration of potentially toxic metals from the orthodontic appliances to the oral environment due to the dynamic dominant conditions. The current study aimed to investigate the effect of the oral environment acidity and aging time on the ion release from orthodontic archwires. For this purpose, dental archwires consisted of three different alloys were immersed in artificial saliva of varied pH values for 7 and 30 days at 37±1°C. The liquid extracts were then analyzed with inductively coupled plasma-optical emission spectrometer (ICP-OES). It was found that the released ion species and the measured concentrations were not in accordance with manufacturers’ data. Furthermore, the leachates were mainly enriched with Cr and Ni ions by decreasing the saliva pH, while most of the archwires released the highest amounts of Ni, Mn and Cr ions after 30 days aging at pH = 3.5. Independent of the material type or the aging conditions, the total release of Ni and Cr ions was within the considered average dietary intake levels.

Fluorinated Agents Effects on Orthodontic Alloys: A Descriptive In Vitro Study

Fluoride-based mouthwashes and gels are preventive measures in countering demineralization and caries but, modifying environmental acidity, can reduce the wet corrosion resistance of orthodontic alloys. To evaluate chemical stability, in vitro experiments were conducted on stainless steel and nickel–titanium wires, weighed before and after immersion in household fluorinated mouthwashes and gels, measuring weight variations and elution of metal ions from acid corrosion phenomena. Elution samples were analyzed by inductively coupled plasma mass spectrometry, detecting residual ion concentration, while surface changes were analyzed under scanning electron microscopy. Results showed stainless steel wires do not undergo significant erosion when exposed to most fluorinated mouthwashes but, at prolonged exposure, alloys elute gradually greater amounts of metals and Ni–Ti wires become more sensitive to some mouthwashes. Ions’ elution varies considerably, especially for Ni–Ti wires, if exposed to household fluorinated gels, for which significant negative values were obtained. Changes, affecting wires’ outer layer, negatively act on shiny appearance and luster, reducing corrosion resistance. Although examined orthodontic wires showed good chemical stability and low toxicity, surface corrosion from exposure to fluorinated agents was observed. Home use must be accompanied by clinician prescription and, for household dental gels, must follow manufacturers’ recommendations, ensuring prophylactic action without damaging alloys surfaces.

Brewed Robusta Coffee Increases Nickel Ion Release from Dental Alloys: An In Vitro Study

Alloys in oral cavity always interact with dynamic oral environment, such as pH, temperature, salivary conditions, and dietary habits. Coffee can further decrease pH in the oral cavity. Thus, coffee may increase the release of metal ions that may lead to various health diseases. This study aimed to quantitively investigate the effect of brewed Robusta coffee on the nickel ion release and their morphological structures; Methods: 20 alloy specimens were divided into 4 groups and placed in solutions for 48 and 168 h: (1) distilled water, (2) artificial saliva, (3) Robusta coffee, and (4) mixture of artificial saliva and Robusta coffee. AAS, XRF, and SEM were used for examinations; Results: The release of Ni²⁺ was found in all groups and robust release were found in the coffee only and mixture of coffee + artificial saliva solution after 168 h. Likewise, SEM showed that internal oxidation was high after 168 h of immersion; Conclusions: The concentration of nickel increased in saliva of low pH due to brewed coffee. Though the release of these ions is still within the tolerable amount in human body, it should be realized that it usually lasts for months or years. Dentists should be cautious when using instructions for patients with a history of allergies especially for dietary with low acidity.

Metal Ion Accumulation on Denture Teeth Following Exposure to Chlorhexidine and Different Drinks: A Spectrometric Analysis

Denture teeth are used for removable prostheses and implant-supportive restorations. The purpose of this study was to analyze the surface of artificial teeth following exposure to different liquids. Mechanical wear and the cleaning of artificial teeth were also investigated. Two groups of resin teeth were used; original surface (Group A) and surface abrasion/wear (Group B). The teeth were exposed for 24 h to water (control), cola (Group 1), coffee (Group 2), tea (Group 3), chlorhexidine (Group 4), and red wine (Group 5). Baseline measurements of liquids were taken. An x-ray fluorescence spectrometric analysis was performed. Data were evaluated using semi-quantitative descriptive analysis. The data showed approximate increases of peak intensity for Group A1-2-fold Fe, 2-fold Ni, 2.2-fold Zn; for Groups A2 and A3- less than 1.5-fold Fe, Ni, and Zn. Group B yielded similar results; however, the increases in Fe, Ni, and Zn were significantly higher in Groups 1 and 2 (ranged 2-4-fold increases in intensity). Group B3 showed little increase in Fe, Ni, and Zn. Groups A4 and A5 showed intensity increases for Zn. Groups A1-A5 showed reductions in intensity following 30 s of cleaning. A pronounced accumulation of iron, nickel, and zinc was found after exposure to liquids, especially when artificial teeth were worn down. Peak intensities were reduced following 30 s of brushing.

Salivary levels of nickel, chromium, iron, and copper in patients treated with metal or esthetic fixed orthodontic appliances: A retrospective cohort study

The purpose of this retrospective cohort study was to measure the salivary levels of nickel (Ni), chromium (Cr), iron (Fe) and copper (Cu) released from metal and esthetic fixed orthodontic appliances. Ninety patients were divided into three groups (n=30): control (those who had never undergone orthodontic treatment), metal appliance (stainless steel brackets and bands, and nitinol archwires) and esthetic appliance (polycarbonate brackets and tubes, and rhodium-coated nitinol archwires). Patients undergoing orthodontic treatment had used their appliances for periods between one and six months. Ni, Cr, Fe and Cu salivary concentrations were measured by the Total Reflection X-Ray Fluorescence technique. Kruskal-Wallis and Bonferroni-Dunn test showed that Ni (p=0.027) and Cr (p=0.040) concentrations were significantly higher for patients undergoing metallic orthodontic treatment than for the esthetic group. No significant difference regarding Ni and Cr (p=0.447) concentrations were observed between the metal and the control groups (p=0.464 and p=0.447, respectively) or between the esthetic and the control groups (p=0.698 and p=0.912, respectively). Ni and Cr concentrations were significantly influenced by the type of appliance used. Fe and Cu concentrations were not affected by the type or use of orthodontic appliances.

Associations between the consumption of carbonated beverages and periodontal disease: The 2008-2010 Korea national health and nutrition examination survey

Consumption of carbonated beverages was reported to be associated with obesity and other adverse health consequences. This study was performed to assess the relationship between the consumption of carbonated beverages and periodontal disease using nationally representative data.The data from the Korea National Health and Nutrition Examination Survey conducted between 2008 and 2010 were used; the analysis in this study was confined to a total of 5517 respondents >19 years old who had no missing values for the consumption of carbonated beverages or outcome variables. The community periodontal index greater than or equal to code 3 was defined as periodontal disease.The odds ratios of the percentage of individuals with periodontal treatment needs tended to increase with the consumption of carbonated beverages. Adjusted odds ratios and their 95% confidence intervals adjusted for various factors including age, sex, body mass index, smoking, drinking, exercise, metabolic syndrome, frequency of tooth brushing per day, use of secondary oral products, dental checkup within a year, consumption of coffee of the individuals with the consumption of carbonated beverages once or less per month, once or less per week and twice or more per week were 1.109(0.804,1.528), 1.404(1.035,1.906), and 1.466(1.059,2.029), respectively. A subgroup analysis revealed that in individuals with body mass index < 25 or waist circumference < 90 cm for males or < 80 cm for females, the prevalence of periodontal disease increased with higher consumption of carbonated beverages (P for trend < 0.05).Consumption of carbonated beverages was positively associated with the risk of periodontal disease in Korean adults. In a subgroup analysis, the individuals consuming carbonated beverages with body mass index < 25 or waist circumference < 90 cm for males or < 80 cm for females were more likely to have periodontal disease. Consumption of carbonated beverages may be considered to be an independent risk indicator for periodontal disease and periodontal health of nonobese individuals may benefit from reduction of carbonated beverage consumption.