RESUMO
BACKGROUND AND OBJECTIVE: To evaluate an intracuring method by changing the corneal curvature. MATERIALS AND METHODS: An intrastromal tunnel was created by femtosecond laser in five cadaveric sheep eyes. Dental flowable restorative composite was used to fill the tunnel. A light-emitting diode light was applied for polymerization for 20 seconds. Flat plastic material was used for pressure on the cornea during polymerization. Keratometric measurements were obtained in all eyes using a rotating Scheimpflug camera. RESULTS: Remarkable changes on the corneal curvature were observed after the intracuring method. Inferior or inferonasal flattening and opposite steepening was observed in all sheep eyes. The average flattening effect of this method was 10.6 diopters. CONCLUSION: This new application may be a promising technique for the treatment of keratoconus. The application of this technique in humans could offer improved treatment options in the future.
Assuntos
Resinas Compostas/uso terapêutico , Córnea , Ceratocone/terapia , Polimetil Metacrilato/uso terapêutico , Próteses e Implantes , Animais , Cadáver , Substância Própria , Topografia da Córnea , Ceratocone/patologia , Implantação de Prótese/métodos , OvinosRESUMO
The purpose of this study was to evaluate the influence of Hero 642 rotary Ni-Ti instruments driven at 300, 400, or 600 rpm on root canal straightening, loss of working length, and instrument breakage. Sixty mesial root canals from extracted human mandibular molars were divided into 3 groups of 20 each and were instrumented at the aforementioned rotational speeds with a crown-down technique. Using a digital intraoral radiography system directly on the images of pre- and postoperative radiographs, degrees of canal curvatures were measured and recorded. Statistical analysis showed that final canal curvatures and working lengths were significantly reduced compared with those of original values in each group (p < 0.001). However, using Hero 642 rotary Ni-Ti system at different rotational speeds had no effect on canal curvature and working length alterations (p > 0.05). No file breakage was observed in any of the groups.
