The anisotropy in the optical constants of quartz crystals for soft X-rays.

The refractive index of a y-cut SiO2 crystal surface is reconstructed from orientation-dependent soft X-ray reflectometry measurements in the energy range from 45 to 620 eV. Owing to the anisotropy of the crystal structure in the (100) and (001) directions, a significant deviation of the measured reflectance at the Si L 2,3 and O K absorption edges is observed. The anisotropy in the optical constants reconstructed from these data is also confirmed by ab initio Bethe-Salpeter equation calculations for the O K edge. This new experimental data set expands the existing literature data for quartz crystal optical constants significantly, particularly in the near-edge regions.

The influence of stress and anxiety on the response of non-surgical periodontal treatment.

AIM: The aim of this study was to evaluate the influence of stress and anxiety on the response to non-surgical periodontal treatment (NPT) in patients with chronic periodontitis. METHOD: Sixty-six patients (mean age 46.1 +/- 8 years) were assigned to three groups: control group, probing pocket depth (PPD) or=4 and 6 mm, n=20. Stress, state anxiety (SA) and trait anxiety (TA) and plaque index (PI), gingival index, PPD and clinical attachment level (CAL) were recorded at baseline and 3 months after NPT. RESULTS: TA scores were different among groups at baseline and after NPT. TA was related to periodontitis at baseline and after NPT. PI was associated with the SA at baseline. The reduction of frequency of CAL >6 mm was correlated with TA after adjusting for confounders. Stressed subjects did not show reduction of frequency of PPD >6 mm (T1), CAL 4-6 mm and CAL >6 mm (T2). CONCLUSIONS: The data suggest an influence of trait of anxiety and stress on the response to NPT.

The relationship of stress and anxiety with chronic periodontitis.

AIM: This case-control study investigates the relationship of stress and anxiety with periodontal clinical characteristics. METHOD: Seventy-nine selected patients (mean age 46.8+/-8 years) were assigned to three groups in accordance with their levels of probing pocket depth (PPD): control group (PPD< or =3 mm, n=22), test group 1 (at least four sites with PPD > or =4 mm and < or =6 mm, n=27) and test group 2 (at least four sites with PPD >6 mm, n=30). An inclusion criterion of the study required that patients presented a plaque index (PI) with a value equal to or larger than 2 in at least 50% of dental surfaces. All subjects were submitted to stress and anxiety evaluations. Stress was measured by the Stress Symptom Inventory (SSI) and the Social Readjustment Rating Scale (SRRS), while the State-Trait Anxiety Inventory (STAI) was used to assess anxiety. Clinical measures such as PI, gingival index (GI), PPD and clinical attachment level (CAL) were collected. Patient's medical history and socioeconomic data were also recorded. RESULTS: The mean clinical measures (PI, GI, PPD and CAL) obtained for the three groups, were: control group, 1.56+/-0.32, 0.68+/-0.49, 1.72+/-0.54 and 2.04+/-0.64 mm; group 1, 1.56+/-0.39, 1.13+/-0.58, 2.67+/-0.67 and 3.10+/-0.76 mm, group 2, 1.65+/-0.37, 1.54+/-0.46, 4.14+/-1.23 and 5.01+/-1.60 mm. The three groups did not differ with respect to percentage of clinical stress, scores of the SRRS, trait and state anxiety. Frequency of moderate CAL (4-6 mm) and moderate PPD (4-6 mm) were found to be significantly associated with higher trait anxiety scores after adjusting for socioeconomic data and cigarette consumption (p<0.05). CONCLUSIONS: Based on the obtained results, individuals with high levels of trait anxiety appeared to be more prone to periodontal disease.