Diffraction and Waveguide Propagation of Light in Tooth Enamel

2020 ◽  
Vol 128 (8) ◽  
pp. 1311-1317
Author(s):  
V. N. Grisimov
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
A. D. Kiselev ◽  
S. V. Pasechnik ◽  
D. V. Shmeliova ◽  
A. P. Chopik ◽  
D. A. Semerenko ◽  
...  

We theoretically analyze the waveguide regime of light propagation in a cylindrical pore of a polymer matrix filled with liquid crystals assuming that the effective radial optical anisotropy is biaxial. From numerical analysis of the dispersion relations, the waveguide modes are found to be sensitive to the field-induced changes of the anisotropy. The electrooptic properties of the polymer porous polyethylene terephthalate (PET) films filled with the nematic liquid crystal 5CB are studied experimentally and the experimental results are compared with the results of the theoretical investigation.


1989 ◽  
Vol 136 (2) ◽  
pp. 97 ◽  
Author(s):  
T.M. Benson ◽  
P.C. Kendall ◽  
M.S. Stern ◽  
D.A. Quinney

Author(s):  
Ш.М. Абрамян ◽  
Е.В. Рожнова ◽  
Е.Н. Волкова ◽  
С.Н. Блохин ◽  
С.Г. Морозов

Цель. Изучение клеток иммунной системы полости рта у пациентов до проведения операции лифтинга лица, а также сопоставление этих данных с показателями, выявленными при осложнениях в послеоперационном периоде. Методика. Исследованы клетки иммунной системы полости рта 100 женщин (23-68 лет), которым перед операцией лифтинга лица проведено стоматологическое обследование и необходимое лечение при наличии кариеса дентина, клиновидного дефекта эмали зуба, хронического периодонтита или пульпита. Выделенные путем смывов десенной борозды клетки окрашивали моноклональными антителами и анализировали на проточном цитометре. Определяли уровень спонтанного и индуцированного апоптоза. Оценивали уровень фагоцитоза и генерацию супероксидного аниона нейтрофилами. Результаты. Показано, что хронические воспалительные заболевания зубов оказывают негативное влияние на состояние иммунных клеток ротовой полости, сопровождаются повышением генерации супероксидного аниона нейтрофилами, повышением уровня спонтанного и церамид-индуцированного апоптоза клеток десенной борозды. Заключение. Наличие хронической патологии зубов, даже после санации, оказывает негативное влияние на течение послеоперационного периода при проведении операции лифтинга лица, в частности, способствует увеличению времени заживления операционной раны, инфицированию раны с появлением очагов некроза в области операционного шва. The object. The study of the cells of the immune system of the oral cavity in patients before the operation of face lifting, as well as a comparison of these indicators with complications in the postoperative period. Methods. The immune cells from the oral cavity were studied in 100 women (23-68 years), who underwent a dental examination and necessary treatment if they had the dentin caries, wedge-shaped defect of tooth enamel, chronic periodontitis or pulpitis before the facial lifting operation. The immune cells have been isolated by a lavage of gingival sulcus around the damaged tooth. Results. It has been shown that chronic dental diseases made a negative contribution to the oral cavity immune cells. It has been accompanied by the elevated levels of superoxide originating from neutrophils as well as the increased levels of spontaneous and ceramide-induced apoptosis of immune cells isolated from the gingival sulcus. Conclusion. The presence of chronic pathology of teeth even in the case of the preoperative dental sanation has a negative impact on the postoperative period after face lifting, in particular, contributes to the lengthening of the surgical wound healing time, wound infection as well as the partial necrosis of suture.


2019 ◽  
Vol 15 (3) ◽  
pp. 156-158
Author(s):  
Aditi Priyamvara ◽  
Amit K. Dey ◽  
Antara Bagchi ◽  
Raveena Kelkar ◽  
Rajaram Sharma

Background: It is known that hormonal imbalances during pregnancy make women more susceptible to dental problems. High levels of progesterone and estrogen during pregnancy, lead to an increased inflammatory response to dental plaque thus causing predisposing to gum diseases such as gingivitis. If untreated, gingivitis leads to chronic periodontitis which may manifest systemically in form of cardiovascular, endocrine or even respiratory disorders. Also, hyperacidity in the oral cavity due to gastric reflux and vomiting leads to decreased pH thus damaging the tooth enamel making the oral cavity more prone to tooth decay and tooth loss. Studies also show that periodontal disease can also lead to adverse pregnancy outcomes such as pre-term and low birth weight babies. Objectives: We sought to understand the role of oral health in pregnancy. Methods: We identified major articles of interest in the field of oral health in pregnancy and drafted a mini-symposium based on relevant information. Conclusion: Regular dental visits and cognizant efforts to sustain a healthy oral environment can help women in the prevention and treatment of dental issues during pregnancy. The paper highlights the common oral manifestations during pregnancy and their local and systemic impact on the body during pregnancy. Furthermore, it also emphasizes the importance of good oral health practices to counteract the oral complications and the significance of oral health awareness in pregnant women.


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