فهرست مطالب susan mir mohammad rezaei

T Laser irradiation of dentin surface can affect its surface topography and roughness. Atomic force microscopy (AFM) is among the most efficient tools for determination of surface topography of natural biomolecules in nano-scales. Surface roughness affects plaque retention especially in the cervical region. This study aimed to assess and compare the obstruction of dentinal tubules and dentin surface roughness after irradiation of erbium: yttrium aluminum garnet (Er:YAG )and CO2 lasers for treatment of dentin hypersensitivity (DH) .
Five disc-shaped samples measuring 3 mm in thickness were fabricated by horizontal sectioning of the cervical area of five extracted human molars using a low speed saw. Each disc was divided into 3 segments by a bur under water coolant. The three segments of each disc were placed on a glass slide. First segment: No intervention (control group). Second segment: Er:YAG laser irradiation (2940 nm, 50 mJ, 10 Hz and 0.5 W, 30 seconds) along with water coolant. Third segment: CO2 laser irradiation (10600 nm, 80 Hz, 0.3 W, 30 seconds) along with water coolant. After that, the surfaces underwent non-contact AFM. The diameters of dentinal tubules as well as surface roughness were then measured and statistically analyzed using repeated measures ANOVA.
The surface roughness parameters (Ra, Rq) showed increased roughness after laser irradiation and this increase in roughness after Er:YAG laser application was significant compared to the control group (P = 0.048). However, CO2 laser caused no significant change in surface roughness. Also, after Er:YAG laser application, fewer open dentinal tubules were observed and the remaining open tubules had a smaller diameter.
Based on the results, Er:YAG laser irradiation obstructs the dentinal tubules and increases the dentin surface roughness. This increase in surface roughness can cause microbial plaque retention and increase the risk of caries and periodontal disease. Application of CO2 laser (compared to Er:YAG) lead to slight but clinically significant obstruction of dentinal tubules and surface roughness

A palatal defect may result from surgical resection, and its consequences could include difficulty in speech and nasal regurgitation of food and liquids. An obturator combined to speech aid prosthesis can improve nasal emission during speech, and assist in preventing nasal regurgitation of food. This article presents a clinical report of the reconstruction of palatopharyngeal function by prosthetic obturator and speech aid.

The use of osseointegrated extraoral implants for retention of extraoral prostheses, such as ears offers ideal support and retention, and improves patient''s appearance and quality of life. However, the best result may be obtained only by careful planning number, position and orientation of the implants and this article presents a method of making of a surgical stent that is simple, economic and stable during all phases of surgery. Case Report: A 26-year-old male (without any remarkable systemic disorder) presented with congenital defect in one ear. An impression was made of congenital defect in left ear, wax pattern of defect and missing ear is made, the wax prosthesis is changed into a clear acrylic resin, and on the other hand an occlusal maxillary splint is also fabricated with clear acrylic resin. The occlusal splint and the acrylic resin ear are joined together using an extraoral bar that is made of proper length of wax and also is checked on patient''s face and processed into a clear acrylic resin. By this kind of surgical guide, we can determine the best location of the implants and location of the implants will not compromise to fabricate ear prostheses with ideal form and location. This surgical guide can be used for the pretreatment of radiographic stent.