Composition and in vitro corrosion of orthodontic appliances

Objective: To compare metal ion release from samples welded with silver soldering and laser welding when immersed into mouthwashes with different ingredients. Materials and Methods: A total of 72 samples were prepared: 36 laser welded and 36 silver soldered. Four samples were chosen from each subgroup to study the morphologic changes on their surfaces via scanning electron microscopy (SEM). Each group was further divided into four groups where the samples were submerged into mouthwash containing sodium fluoride (NaF), mouthwash containing sodium fluoride + alcohol (NaF + alcohol), mouthwash containing chlorhexidine (CHX), or artificial saliva (AS) for 24 hours and removed thereafter. Subsequently, the metal ion release from the samples was measured with inductively coupled plasma mass spectrometry (ICP-MS). The metal ion release among the solutions and the welding methods were compared. The Kruskal-Wallis and analysis of variance (ANOVA) tests were used for the group comparisons, and post hoc Dunn multiple comparison test was utilized for the two group comparisons. Results: The level of metal ion release from samples of silver soldering was higher than from samples of laser welding. Furthermore, greater amounts of nickel, chrome, and iron were released from silver soldering. With regard to the mouthwash solutions, the lowest amounts of metal ions were released in CHX, and the highest amounts of metal ions were released in NaF + alcohol. SEM images were in accord with these findings. Conclusions: The laser welding should be preferred over silver soldering. CHX can be recommended for patients who have welded appliances for orthodontic reasons. (Angle Orthod. 2015;85:665-672.)

Section: Discussionmentioning

confidence: 99%

“…3,9 Grimsdottir et al 3 reported that facial arches prepared with silver soldering were corrosion sensitive. This outcome was thought to be related to the 300u-500uC heat applied during soldering.…”

Section: Introductionmentioning

confidence: 99%

Metal ion release from silver soldering and laser welding caused by different types of mouthwash

Erdogan

Nalbantgil

Ulkur

et al. 2014

“…In 1992, Grimsdottir et al 10 conducted an in vitro study to investigate the cytotoxicity of some metals employed in orthodontics and demonstrated the biocompatibility of stainless steel archwires. However, the orthodontic bands revealed cytotoxic effects that might be associated with the use of silver soldering and copper soldering in their fabrication.…”

Section: Introductionmentioning

confidence: 99%

Cytotoxicity of Silver Solder Employed in Orthodontics

Freitas

Oshima

Menezes

et al. 2009

Objective: To test the null hypothesis that the silver soldering employed in orthodontics is not cytotoxic for fibroblasts. Materials and Methods: This in vitro study was performed using a culture of mice fibroblasts (lineage NIH/3T3), divided into four groups (n ϭ 10 each): control, negative control (stainless steel archwire), positive control (amalgam disks), and test group (silver soldering). After cell culture in complete Dulbecco modified eagle medium and achievement of confluence in 80%, the suspension was added to the plates of 24 wells containing the specimens and incubated in an oven at 37ЊC for 24 hours. The plates were analyzed on an inverted light microscope, photomicrographs were obtained, and the results were recorded as response rates based on modifications of the parameters of Stanford according to the size of the diffusion halo of the toxic substance and quantity of cell lysis. Results:The results revealed a maximum response rate for the silver soldering group, as well as severe inhibition of cell proliferation and growth, more round cells with mostly darkened and granular aspects, suggesting lysis with cell death. A similar response was seen in the positive control group. Conclusion: The hypothesis is rejected. The silver soldering used in orthodontics represents a highly cytotoxic material for the cells analyzed. (Angle Orthod. 2009;79:939-944.)

“…In this way, sensitization to nickel develops much more easily in the presence of strong inflammation. At the inflammation site, reactive oxygen species such as hydrogen per- oxide (H 2 O 2 ) and hypochlorite (OCL Ϫ ) 4 are produced by phagocytes. 18 In the case of nickel hypersensitivity, these powerful oxidants can oxidize Ni 2ϩ to the higher oxidation states of Ni 3ϩ and Ni 4ϩ , respectively, 19 which have a far greater chemical reactivity than Ni 2ϩ .…”

Section: Discussionmentioning

confidence: 99%

“…Allergic reactions in the oral region to metals contained in dental appliances has previously been reported, [1][2][3] and increased attention has been paid to allergy to orthodontic materials. [4][5][6] Some metals com-monly used in dental practice are known allergens such as nickel, cobalt, and chromium, many of which are contained in various kinds of orthodontic material. 7 Nickel is the most typical antigen of metal-induced allergic contact dermatitis, [8][9][10] whereas a chromium allergy is estimated to occur in 10% of male subjects and 3% of female subjects.…”

Section: Introductionmentioning

confidence: 99%

Treatment of a Patient with Metal Hypersensitivity after Orthognathic Surgery

Kitaura

Fujimura

Nakao

et al. 2007

In this case report, orthodontic materials may have induced metal allergic reactions in the form of lip swelling and redness after orthognathic surgery. Two months after surgery, the patient suffered continuous lip swelling and redness. She visited a dermatological hospital and was diagnosed with herpes. However, since her symptoms did not improve after 1-month of drug therapy, a metal allergy was subsequently suggested. Patch tests conducted in the dental hospital revealed reactions to chromium, which is not used in prosthetic appliances. For confirmation, the metal composition of all prosthetic appliances was examined using a fluorescent x-ray analyzer, but no chromium was detected (copper, gold, palladium, and silver were detected). However, the orthodontic brackets, wires, and bands do contain chromium and, considering that they may have induced the metal allergic reactions, they were replaced with materials made of polymer with no metals. As a result, the lip swelling and redness improved. For retention, the anterior part of the retainer was bonded on the lingual side of the anterior lower and upper jaws. During retention, no further symptoms of hypersensitivity were observed, suggesting that the nonmetal polymer is useful for treatment of metal allergic patients.