Localized Energy Estimates for Wave Equations on Higher Dimensional Black Holes

A robust measure of decay and dispersion for the wave equation is provided by the localized energy estimates, which have been essential in proving, e.g. the Strichartz estimates on black hole backgrounds. We study localized energy estimates for the wave equation on (1+4)-dimensional Myers-Perry space-times, which represent a family of rotating asymptotically at black holes with spherical horizon topology and generalize the well-known Kerr space-times to higher dimensions. Because of the extra dimension, the Myers-Perry family is parameterized by two angular momentum parameters, which we assume to be sufficiently small relative to the mass of the black hole, essentially allowing us to treat the space-time as a perturbation of the Schwarzschild black hole. This investigation is motivated by the nonlinear stability problem for the Kerr family of black holes, which may be easier to understand in higher dimensions. Typically, the localized energy estimates are proved by commuting the wave operator with a suitable first-order differential operator and integrating by parts. However, the underlying black hole geometry introduces a number of difficulties related to the trapping phenomenon, which is a known obstruction to dispersion and necessitates a loss in decay. This phenomenon is manifest along the event horizon of the Schwarzschild/Kerr black holes, but its effect is rendered negligible due to the celebrated red-shift effect. More delicate analysis is required to deal with trapping that occurs along e.g., the so-called photon sphere in the Schwarzschild geometry. Localized energy estimates on higher dimensional Schwarzschild black holes were proved by Laul-Metcalfe in [34] using a single differential multiplier, but their method relies fundamentally on the fact that the trapped null geodesics lie on a sphere. On the Myers-Perry space-time, the nature of the trapped set is much more complicated and must be described in phase space rather than by position alone, and consequently a single differential multiplier is insufficient to prove the desired result. Once it is determined that all trapped geodesics lie on surfaces of constant r, we can adapt the method of Tataru and Tohaneanu in [62], which perturbs off the Schwarzschild case by instead commuting with an appropriate pseudodifferential operator to generate a positive commutator near the trapped set. This describes joint work with Parul Laul, Jason Metcalfe, and Mihai Tohaneanu [35].Bachelor of Scienc

Efficacy of Pluronic F-127 gel containing green tea catechin extract on chronic periodontitis – A clinical study

Purpose: To evaluate the efficacy of pluronic F-127 gel containing green tea catechin extract as a local drug delivery system in the treatment of chronic periodontitis. Methods: A total of 20 chronic periodontitis patients participated as per the set inclusion and exclusion criteria. Complete scaling and root planing (SRP) was done for all subjects and pluronic F-127 gel containing green tea catechin was applied on one site. The contralateral site received SRP alone. The plaque index (PI), gingival index (GI), and probing pocket depth (PPD) were recorded at baseline and on the 28th day. Results: At the 28th-day follow-up, green tea catechin tooth sites showed significantly lower mean scores (GI = 0.55, p = 0.30 and PPD = 3.35 mm) than the corresponding SRP tooth sites (GI = 1.25, PI = 1.15, and PPD = 4.40 mm) (p < 0.05). Conclusion: When compared to scaling and root planing alone, the local drug delivery gel containing green tea catechin as an adjuvant was more effective in reducing the clinical parameters of periodontitis. Keywords: Adjuvant therapy, Camellia sinensis, Local drug delivery, Periodontal pocke

Oral health knowledge and attitudes of primary school teachers toward school-based oral health programs in Abha-Khamis, Saudi Arabia

Background: The effectiveness of school-based dental health programs has been vastly reported. The objective of the present study was to assess the oral health knowledge and attitudes of primary school teachers in Saudi Arabia and to identify any barriers in implementing school oral health programs. Methodology: A pretested self-administered questionnaire was used to assess the oral health knowledge and attitudes of primary school teachers including barriers in implementing school oral health programs. Results: A total of 61 primary schools were included in the present study with responses from 1186 teachers. The mean oral health knowledge score among primary school teacher of Abha-Khamis was found to be 16 ± 2.7. The overall attitude of primary school teachers regarding implementing school-based oral health program was found to be positive on Likert scale. The responses for barriers in implementing school oral health program were almost equally distributed: lack of material resources (21%), lack of professional training (25%), lack of availability of time (25%), lack of support from school administration (22%), and teacher's attitude was least perceived as a barriers (7%). Conclusions: The oral health knowledge among primary school teachers was found to be good with positive attitudes toward school-based oral health programs. The most significant barriers in implementing a school oral health program were administrative barriers. There is a need for concerned school authorities and health policy makers to address these barriers and to promote oral health in the community

Perception of diet counseling among dental students in India

Introduction: Nutrition has always been recognized as an integral part of oral health. However, most dentists do not incorporate diet counseling in routine dental practice. The current study was set to evaluate the knowledge, attitude, and practice (KAP) on diet counseling among dental house surgeons. Materials and Methods: Interns from four different colleges (under different universities) spread across the four states of South India were selected. Of them, 220 interns who completed the questionnaires were chosen for final analysis. Results: Of the subjects, 75% agreed that nutrition was a vital component of total health care. However, only 42% of the subjects reported that they had received adequate training in diet counseling. Most of the subjects agreed that diet counseling needed to be emphasized in dental education and only 37% of the subjects expressed their confidence in rendering diet counseling to their patients. Conclusions: Students possessed not only good knowledge but also a positive attitude toward diet counseling. Lack of confidence and apprehension about financial reimbursement were two main reasons cited as obstacles for the incorporation of diet counseling in routine clinical practice

Immunization practice in patients with chronic kidney disease on haemodialysis

Background: Immunization is an important component of maintaining health and wellness in patients with chronic kidney disease. The aim of the study is to describe the awareness about the vaccination in patients with chronic kidney disease on haemodialysis and to estimate the vaccination status received in these patients on dialysis. Methods: It is a cross sectional study conducted in 83 patients diagnosed to have chronic kidney disease undergoing dialysis for at least 1 month. Demographic characteristics and comorbidity data (as self-reported) were collected and questionnaire assessment was filled about the vaccination and counselling received. Results:  The prevalence of CKD were 73.5% in males and 26.5% in females with a mean age of 48.9 years. Among the different occupations of the patient with no job/housewife was 56.6% while professional jobs were 18.1% business and non-professional source were 13.3% and agriculture related was 12.0%. Evaluation of education stated that patients educated with higher schooling had 15.6% of prevalence of CKD compared to degree holders and Masters. The different comorbidities among the studied patients were Hypertension- 84.3%, Diabetes- 47%, Stroke- 12%, Connective tissue disorder- 18.1% and COPD- 44.6%

Evaluation of Propolis Hydrogel for the Treatment of Dentinal Sensitivity: A Clinical Study

Background: Propolis is a natural resinous substance collected by honeybees, chiefly from buds and the leaves, branches, and bark of trees. Its role as a wound-healing gel has been studied, but the use of a propolis hydrogel in the treatment of dentinal hypersensitivity has not been evaluated. Dentin hypersensitivity (DH) is commonly treated via iontophoresis using fluoridated desensitizers. The aim of the present study was to compare and evaluate the effects of a 10% propolis hydrogel, 2% sodium fluoride (NaF), and 1.23% acidulated phosphate fluoride (APF) when used in conjunction with iontophoresis for the treatment of cervical dentin hypersensitivity (DH). Methods: Systemically healthy patients complaining of DH were selected for this single-centre, parallel, double-blind randomized clinical trial. Three substances were selected as desensitizers for study in the present trial: a 10% propolis hydrogel, 2% sodium fluoride, and 1.23% acidulated phosphate fluoride, all in conjunction with iontophoresis. Any decrease in DH following the application of specific stimuli was assessed at baseline, before and after application, on the 14th day following use, and on the 28th day following the intervention. Results: Intra-group comparisons show diminished values of DH at maximum post-op follow-up intervals which were significantly trimmed down from the baseline (p p p > 0.05). Conclusion: All three desensitizers have proved to be useful when used in conjugation with iontophoresis. Within the limitations of this study, a 10% propolis hydrogel can be used as a naturally occurring alternative to commercially available fluoridated desensitizers

Effect of Injectable Platelet-Rich Fibrin with a Nano-Hydroxyapatite Bone Graft on the Treatment of a Grade II Furcation Defect

Background: Periodontal diseases lead to bone loss, crestal defects and even loss of the tooth, which also further makes it difficult to replace the tooth. Autogenous bone grafts are considered the gold standard in bone regenerative procedures. This study aimed to compare and evaluate the bone regenerative effects of i-PRF (Injectable- Platelet-rich fibrin) with a bone graft and a bone graft alone in mandibular grade II furcation defects over a period of 9 months. Method: This was a comparative study of 12 participants, who were randomly selected and grouped into two groups: test and control. Following phase I therapy, both groups were subjected to open flap debridement. In the test group, after debridement, a nano-hydroxyapatite bone graft mixed with i-PRF was inserted, whereas in the control group only a nano-hydroxyapatite bone graft was inserted. The clinical parameters such as plaque index (PI), gingival index (GI), pocket probing depth (PPD), clinical attachment level (CAL), horizontal probing depth (HPD) and vertical probing depth (VPD) were recorded at baseline, 3 months, 6 months and 9 months following the surgery. The bone area fill (BAF) was assessed using intraoral periapical radiographs (IOPARs) taken at baseline and 9 months after surgery. Results: At the baseline, there was no statistically significant difference between the tested parameters. After 9 months all the clinical parameters, PI, GI, PPD, CAL, HPD and VPD as well as radiographic bone fill showed a significant increase in both the groups (p < 0.05) (PI-TGr; CGr–VPD—3.5 ± 0.54 to 0.66 ± 0.51; 3.3 ± 0.81 to 2 ± 0.63/BAF—2.9 ± 0.88 to 5.6 ± 1.10; 3.4 ± 1.39 to 3.9 ± 1.4). On comparison the test group showed better results for each clinical parameter. Conclusion: The results showed increased improvement in clinical conditions in both groups, although better results were seen in the group where i-PRF with a nano-HA bone graft was used in the furcation defect

Comparative Evaluation of Locally Administered 2% Gel Fabricated from Lemongrass Polymer and 10% Doxycycline Hyclate Gel as an Adjunct to Scaling and Root Planing in the Treatment of Chronic Periodontitis—A Randomized Controlled Trial

Background: Extracts of medicinal plant like lemongrass offer a new choice for optional antimicrobial therapy against various oral microorganisms. The objective of this study was to assess, verify, and compare the antimicrobial effectiveness of locally administered 2% lemongrass gel and 10% doxycycline hyclate gel as an adjunct to scaling and root planing (SRP) in treating chronic periodontitis. Method: This is a double-blind parallel arm randomized controlled study. Forty subjects were randomly divided into Group A and B for 2% lemongrass gel and 10% doxycycline hyclate gel, respectively. The clinical assessments of Gingival Index (GI), Plaque Index (PI), Probing Pocket Depth (PPD), and Clinical Attachment Level (CAL) together with microbial colony counts for Porphyromonas gingivalis, Actinomyces naeslundii, and Prevotella intermedia were done at baseline, 1st month, and 3rd month follow-ups. Results: The results showed there was a significant reduction in the mean scores of GI, PPD, and CAL clinical indices from baseline to the 1st and 3rd month follow-ups in both the 2% lemongrass gel and 10% doxycycline gel groups (p < 0.05). Similarly, there was significant reduction in mean CFU scores for all periodontal pathogens from baseline to 1st and 3rd month follow-ups in both the 2% lemongrass gel and 10% doxycycline gel groups (p < 0.05). Conclusions: It could be concluded that the local delivery of 2% lemongrass gel as an adjunct to scaling and root planing is effective and comparable to 10% doxycycline gel in the treatment of chronic periodontitis