Cytotoxicity of orthodontic bonding adhesive resins on human oral fibroblasts

Abstract

There is little information concerning the cytotoxic effects of no-mix and flowable adhesives used in orthodontics. The aim of the present study was to evaluate the cytotoxic effects of a no-mix (Unite), a light-cured (Tranbond XT), and a flowable (Denfil Flow) adhesives on human oral fibroblasts. Twelve discs of each adhesive were prepared and aged for 1, 3, 5, and 7 days in Dulbecco's Modified Eagle's Medium (DMEM). Cell viability was assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the difference between the groups was tested by analysis of variance and Tukey tests (α = 0.05). After 1 day of storage, the no-mix adhesive showed moderate cytotoxic effects (P < 0.05), while the light-cured and flowable adhesives were essentially non-cytotoxic. Ageing considerably reduced the cytotoxicity of the no-mix adhesive. On days 5 and 7 of the experiment, the cell viability of three adhesives did not differ significantly (P > 0.05), but cell viability was slightly reduced on day 7. Moderate cytotoxic effects of no-mix adhesive on the first day of the experiment suggest that care should be taken to protect dentists and patients when these adhesives are being handled. Despite higher resin components, the flowable adhesive showed excellent biocompatibility.

Effect of degree of conversion on in vivo biocompatibility of flowable resin used for bioprotection of mini-implants

“…1 On the other hand, the monomers released by resins are cytotoxic to fibroblasts, 13 which can induce local and systemic reactions in patients, 14 causing epithelial proliferation, lichenoid reactions, 15 hypersensitivity, and allergic reactions. 15,16 The main cause of the cytotoxic effects of resins is the release of unpolymerized residual monomers, 2,7,11,17 which may cause severe cellular damage 3,10,17 and favor bacterial growth around the resin. 18 Studies 19,20 have demonstrated that flowable resins are more cytotoxic than traditional resin composites.…”

In Vitro Cytotoxicity Assessment of an Orthodontic Composite Containing Titanium-dioxide Nano-particles

“…The adhesive specimens were prepared in the same thickness as that used under brackets to provide data relevant to the clinical conditions. 17,25 HGF cells were selected because of their abundance in the gingiva where excess bonding material would be frequently observed. The MTT assay used in this study is a simple, sensitive, reliable and commonly used enzymatic assay to determine the cytotoxicity of various medicinal and toxic materials.…”

“…Biocompatibility of different types of orthodontic adhesives and their ingredients have been investigated in several studies and most indicated cytotoxic effects of different intensity, 17-20 due to the release of unbound molecules from the structure of cured composites. 17,21 Incorporation of nano-particles to composite structure may result in additional health hazards because of the specific structural and chemical properties of nanoparticles.…”

“…17,21 Incorporation of nano-particles to composite structure may result in additional health hazards because of the specific structural and chemical properties of nanoparticles. 22 To the best of the authors’ knowledge, there is no study regarding the biocompatibility of composites containing TiO 2 nano-particles.…”

Ortodonti̇de Kullanilan Malzemeleri̇n Si̇totoksi̇si̇tesi̇ni̇n Değerlendi̇ri̇lmesi̇

“…Diğer taraftan, adeziv kalınlığın-daki artış yetersiz aktivatör penetrasyonuna sebep olacağından homojen olmayan polimerizasyon paterni üreterek, sitotoksisiteyle sonuçlanacaktır. 32 Polimerizasyon derecesi, bir rezin adezivin ne kadar polimerize olduğunu ifade eder ve monomer moleküllerin ve materyale ulaşan ışık ve enerjinin özelliklerine bağlıdır. Polimerizasyon derecesi arttıkça, rezin adevizin çözünürlüğü ve bozulması azalmaktadır.…”