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Notes: The stretching and bending of polished and industrial-grade metallurgical surfaces changes the appearance of the specimen's surface. The changes in surface structure can be detected in the polarized light scattered from the surface cracks and other defects, which act as scattering centers. In order to interpret light scattering signals from complex surfaces, we first examine the nature of light scattered from a perfect mirror surface, a degraded mirror, a line on a mirror, a randomly sanded surface, and, finally, the industrial grade metal surfaces damaged by stretching and bending.

Notes: We have analyzed the jet-cooled torsional spectra of the S1–S0 transitions for the seven monomethyl indoles. The potential curves which describe the hindered internal rotation in both the ground and excited states are modeled with the form: V(φ)= 1/2 ∑n Vn(1−cos nφ). The changes in the torsional potential upon electronic excitation can be interpreted as arising from changes in the electron density adjacent to the methyl rotor. We present evidence that the methyl rotor is then a unique probe with which to obtain information about the detailed electronic structure of the parent indole molecule. This approach provides new evidence for the assignment of the first excited electronic state of indole observed in the vapor phase to 1Lb.

Notes: The two-photon excitation spectrum of the 1Au(S1)–1Ag(S0) transition in trans-glyoxal is observed in the region of 21 800–25 400 cm−1. The excitation source is the H2 Raman shifted output of a pulsed dye laser. The source yields tunable output from 0.7 to 1.4 μm and enables both one- and two-color two-photon spectra to be observed. These spectra are complementary to the well known one-photon spectra for this transition. However, the two-photon selection rules cause much of the vibrational structure to be simplified. Many of the observed bands belong to the torsional mode, ν7, revealing vibrational quanta up to 12 in the excited state and 8 in the ground state. The two-photon rotational contours for a number of transitions are calculated for comparison with the observed spectra.

Notes: A vibrational analysis for the excitation and fluorescence spectra of the S1–S0 transition in jet-cooled indole and N-deuterated indole is presented. This analysis yields the frequencies for eight low-lying S1 vibrational modes of both isotopic species. Single vibronic level fluorescence spectra also enable us to refine many of the S0 vibrational frequencies. Quantum interference effects in the energy-resolved fluorescence decays for one vibrational level of S1 indole are observed as a result of picosecond laser excitation. Through analysis of the fluorescence spectra and the modulated fluorescence decays, the coupling responsible for the quantum beats was found to result from a zero-order in-plane mode coupled to a level which is described by several zero-order out-of-plane modes. The effect of the deuterium substitution on the quantum beats is also investigated.

Notes: Abstract The aim of the present study was to evaluate the effect of a strict supragingival plaque control regimen on bacterial repopulation following scaling and root planing. 7 patients with moderate to severe inflammatory periodontal disease received a full-mouth scaling and subgingival curettage. Using a split-mouth design. 2 sites of opposite quadrants were submitted to professional supragingival plaque control 3 × a week while the contralateral sites served as controls. Clinical and bacterial examination were performed on days 7, 14. 28, 49, 56, 63 and 70 following therapy. All clinical parameters (PII, GI, probing depth, attachment levels) showed significant improvement after scaling and root planing. Shifts in the subgingival bacterial population observed by dark field were also noticed following curettage: there was a decrease in the proportions of spirochetes and motile rods and an increase in that of coccoid cells. However, bacterial distribution tended to return to base line values towards the end of the observation period. No difference in the pattern of bacterial recolonization of the subgingival area could be detected between the sites under strict supragingival plaque control and the control sites.

Notes: Abstract The aim of this study was to evaluate the effect of supragingival plaque control on the composition of the subgingival microflora. 8 subjects with moderate to severe periodontitis were chosen for the study. Sites with periodontal destruction (GI 〉 2; probing depth 〉 6.5 mm; vertical alveolar bone loss on radiographs) were submitted to professional plaque control 3 × a week for 3 weeks. Contralateral sites received no prophylaxis and served as controls. Patients maintained usual oral hygiene during the observation period: it consisted exclusively of tooth brushing once or twice a day with no use of interdental cleaning aids. Clinical examination and bacterial sampling were performed every week. At the end of the study. PII scores for the experimental sites showed a marked diminution compared with the control sites. No variations were observed in GI or probing depth in test or control sites during the study. The composition of subgingival plaque in both groups showed no significant variations during that period.

Notes: Abstract 38 first or second lower molars from 16 patients showing furcation involvements of degrees 1 and 2 were treated after motivation and hygiene instruction, either by subgingival curettage, or by the modified Widman surgical procedure or by furcation plasty. The plaque index, the gingival index of inflammation and the depth of interproximal and interradicular pockets were recorded before and up to 1 year after the 3 therapeutical procedures. The above clinical indices were also followed for 1 years in 15 lower molars from 7 untreated patients. A quantitative radiographical analysis of the interradicular bone was performed in all patients, by using superposable identical radiographs and a computer-assisted photodensitometric technique.In the 3 groups of treated patients, the clinical scores were, in general, improved by the 3 therapeutic modalities. In the furcation areas, the plaque index was always higher on the lingual side, whereas the depth of “horizontal” pockets was always greater on the buccal side. Except for the lesions treated by furcation plasty, no change could be noticed clinically in the depths of vertical or horizontal penetration of a periodontal probe in the furcation areas. The quantitative radio-graphic analysis, however, clearly showed a loss in the first 2 mm of superficial bone during the 2 months following the 3 therapeutical procedures: this loss was followed by a statistically significant recovery and, for the group treated by curettage, even by a net gain during the 6 to 12 months following therapy. The radiographical density of the deeper layer of bone did not change in the group treated by curettage only. It showed a loss in the first 2 months following the 2 surgical procedures but a statistically significant recovery in the months thereafter.As for the group of untreated patients, at the examinations performed initially, 6 months, 1 and 2 years later, the number of plaque-free and non-bleeding sites in the furcation areas was lower on the lingual as compared to the buccal side, whereas the frequency distribution of furcation involvements was similar on both aspects. No significant changes were found in the various clinical parameters throughout the 2 years of the study. On the contrary, a significant loss of average density of the superficial layer of interradicular bone was already measured on the superposable radiographs 6 months after the initial examination and was found to increase thereafter. No changes of radiodensity could be measured for the deeper layer of bone. The statistical analysis on the relationship between probing scores and radiographical measurements failed to show any predictability between clinical probing measurements and bone loss in the furcation areas.

Notes: Abstract Superposable radiographs of lower molar areas were obtained by means of a specially designed film holder and a gnathostat maintained in a constant position with respect to long-cone radiological equipment. A quantitative evaluation of the bone mass in the interradicular area was obtained by scanning the area under a photodensitometer. A photodensitometric scan of the image of an aluminium wedge adapted to each radiograph was also performed. This allowed the transformation, with the aid of a computer, of the photodensitometric recording of bone into a tracing of mm of aluminium equivalents. The reproducibility and precision of the method were verified by comparing magnifications of repeated radiographs, by photodensitometric readings of radiographs developed in different batches and by repeated quantitative readings of the same film. The method allowed one, for instance, to follow quantitatively the healing of a radiographically visible periapical lesion. It was also used to evaluate quantitatively, in the interradicular area, bone changes which could not be seen with the naked eye.

Notes: In physiological and pathological conditions, the pH of the crevicular fluid may play a significant role on the structure and function of the gingival crevice. In the present investigation the pH of human crevicular fluid was determined by a new microanalytical technique. The fluid was collected in 32 sites (19 patients) with capillary tubes. The tip of a double barreled, neutral carrier based microelectrode, highly selective for H+ ions was introduced directly into the capillary tubes containing either the samples or the reference solutions. In each sampling site, the GI and the crevicular fluid volume were recorded and correlated with the pH. As the inflammation increased, an elevation of pH from 6.90 to as much as 8.66 was observed. These values have been measured at 20°C in absence of CO2.Whether this increase is due to the bacterial flora or to any metabolic activity in the crevice area is not clear at the moment.