RESUMEN
BACKGROUND: Monomers of methacrylates used in restorative dentistry have been recently reported to induce DNA double-strand breaks (DSBs) in human gingival fibroblasts (HGFs) in vitro. Because such monomers may penetrate the pulp and oral cavity due to the incompleteness of polymerization and polymer degradation, they may induce a similar effect in vivo. DSBs are the most serious type of DNA damage and if misrepaired or not repaired may lead to mutation, cancer transformation and cell death. Therefore, the protection against DSBs induced by methacrylate monomers released from dental restorations is imperative. MATERIAL/METHODS: We examined the protective action of chitosan oligosaccharide lactate (ChOL) against cytotoxic and genotoxic effects induced by monomers of the model adhesive consisting of 55% bisphenol A-diglycidyl dimethacrylate (Bis-GMA) and 45% 2-hydroxyethyl methacrylate (HEMA). We evaluated the extent of DSBs by the neutral comet assay and the phosphorylation of the H2AX histone test. RESULTS: ChOL increased the viability of HGFs exposed to Bis-GMA/HEMA as assessed by flow cytometry. ChOL decreased the extent of DSBs induced by Bis-GMA/HEMA as evaluated by neutral comet assay and phosphorylation of the H2AX histone. ChOL did not change mechanical properties of the model adhesive, as checked by the shear bond test. Scanning electron microscopy revealed a better sealing of the dentinal microtubules in the presence of ChOL, which may protect pulp cells against the harmful action of the monomers. CONCLUSIONS: ChOL can be considered as an additive to methacrylate-based dental materials to prevent DSBs induction, but further studies are needed on its formulation with the methacrylates.
Asunto(s)
Bisfenol A Glicidil Metacrilato/toxicidad , Quitosano/metabolismo , Roturas del ADN de Doble Cadena , ADN/efectos de los fármacos , Cementos Dentales/toxicidad , Lactatos/metabolismo , Metacrilatos/toxicidad , Oligosacáridos/metabolismo , Animales , Bisfenol A Glicidil Metacrilato/química , Supervivencia Celular/efectos de los fármacos , Quitosano/química , Quitosano/farmacología , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Fibroblastos/fisiología , Encía/citología , Histonas/metabolismo , Humanos , Lactatos/química , Lactatos/farmacología , Metacrilatos/química , Estructura Molecular , Oligosacáridos/química , Oligosacáridos/farmacología , Resistencia al CorteRESUMEN
We report the case of a 49-year-old patient with megalocornea and coexisting corneal astigmatism. The corneal diameter in the right eye was 15.0 mm and in the left eye, 14.9 mm. In both eyes, a nuclear sclerotic cataract developed, with the tendency toward cortical mass swelling in the right eye. The aim of surgical treatment was to remove the cataract with simultaneous correction of corneal astigmatism by implanting an Acrysof toric intraocular lens (IOL). Intraocular lens stabilization was obtained by suturing it to an capsular tension ring (CTR) in the anterior chamber. The IOL-CTR complex was rotated into the lens capsule and aligned with the steep meridian of corneal astigmatism. The surgical technique provides a stable refractive and functional effect in patients with megalocornea and coexisting cataract and corneal astigmatism.