Orthodontic Adhesives Induce Human Gingival Fibroblast Toxicity and Inflammation

Abstract

Objective: To test the null hypothesis that the resin base and the resin hybrid glass ionomer base adhesives do not cause inflammation after contacting primary human gingival fibroblasts in vitro. Materials and Methods:The resin base and resin hybrid glass ionomer base adhesives were used to treat human gingival fibroblasts to evaluate the survival rate using MTT colorimetric assay to detect the level of cyclooxygenase-2 (COX-2) mRNA by reverse transcription polymerase chain reaction (RT-PCR) technique and COX-2 protein expression using Western blot analysis. The results were analyzed using one-way analysis of variance (ANOVA). Tests of differences of the treatments were analyzed using the Tukey test and a value of P Ͻ .05 was considered statistically significant. Results:The paste and primer of the resin base adhesive and the liquid of glass ionomer adhesive showed decreasing survival rates after 24 hours of treatment (P Ͻ .05). All orthodontic adhesives induced COX-2 protein expression in human gingival fibroblasts. The exposure of quiescent human gingival fibroblasts to adhesives resulted in the induction of COX-2 mRNA expression. The investigations of the time-dependent COX-2 mRNA expression in adhesive-treated human gingival fibroblasts revealed different patterns. Conclusions:The hypothesis is rejected. For orthodontic patients with gingival inflammation, except for those with oral hygiene problems, the activation of COX-2 expression by orthodontic adhesive may be one of the potential mechanisms.

Cytotoxicity of Three Light-Cured Orthodontic Adhesives

“…Orthodontic adhesives are used to glue attachments directly to the tooth surface. An ideal orthodontic adhesive should have good chemical and physical properties, non-irritating to surrounding tissue, and easy to manage [2]. However, biocompatibility of dental materials is usually neglected in dental practice.…”

Comparison of two methods of visual magnification for removal of adhesive flash during bracket placement using two types of orthodontic bonding agents

“…In addition, orthodontic bonding agents are known to be toxic to human gingival fibroblasts, thereby causing inflammation and gingival hyperplasia even in the presence of good oral hygiene. 11 Therefore, careful removal of the bonding agent would reduce the risk of demineralization during orthodontic treatment.…”

Comportement en milieu buccal

“…Tous les systèmes de colles orthodontiques (à base de résine ou de verre-ionomères chargé en résine) pour brackets en contact avec des fibroblastes gingivaux in vitro provoquent l'expression de la protéine cyclooxygénase-2 (COX-2). Il est donc probable que, sauf en cas de problèmes d'hygiène, l'activation de l'expression de la COX-2 par les adhésifs orthodontiques soient un mécanisme potentiel de développement de l'inflammation gingivale [56].…”