TY - BOOK AU - Akram Ismail Abdelrahman Ismail AU - Tarek Abdelhamid Harhash , TI - Comparison between the effect of diode Laser 980nm and LED light in two different H₂O₂ Concentrations bleaching gels : : An in vitro study / PY - 2021/// CY - Cairo : PB - Akram Ismail Abdelrahman Ismail , KW - Diode Laser 980nm KW - H₂O₂ KW - LED light N1 - Thesis (M.Sc.) - Cairo University - National Institute of Laser Enhanced Sciences - Department of Leaser Application on Oral Surgery / Dentistry; Issued also as CD N2 - Background: Color problems may affect the teeth, and the causes of these problems vary.The causes of tooth staining must be carefully evaluated for better results about the predicted color improvement, since some stains are hard to remove and may need additional intervention or multiple bleaching sessions.Tooth discolorations may be extrinsic or intrinsic. Aim: Compare between Diode laser 980 nm and LED light (420 nm- 480 nm) with two concentrations (35% - 16%) of hydrogen peroxide bleaching gel to determine the least side effects on certain tooth elements with the same tooth shade change.Materials and Methods: Fifty human freshly extracted maxillary central and lateral incisors were selected in different shades, cleaned and kept hydrated in saline solution, were used. Five experimental groups (n = 10 each group): Group (A): Diode laser 980nm with 35% H₂O₂ bleaching gel, group (B): Diode laser 980nm with 16% H₂O₂ bleaching gel, group (C): LED light (420 nm {u2013} 480 nm) with 35% H₂O₂ bleaching gel, group (D): LED light (420 nm {u2013} 480 nm) with 16% H₂O₂ bleaching gel and group (E): negative control group (untreated). Teeth shade, hue, temperature, chemical (minerals 2Ca & P3)and morphological changes were registered.Thermocouple thermometer was used to detect temperature changes, EDXS was used for detection of chemical (minerals 2Ca & P3) changes and SEM was used to detect morphological changes in enamel and dentin. Results: No significant differences in color change were seen between groups. Significant changes were seen in hue, temperature, enamel chemical content (minerals 2Ca & P3) and morphology of enamel and dentin ER -