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Notes: Abstract The nature of the relationship between dental plaque and chronic inflammatory periodontal disease (CIPD) remains unclear, although there is no doubt that plaque is the direct cause. Non–specific, specific and exogenous hypotheses have been proposed to explain plaque-host relationships. Current evidence indicates that plaque is part of the natural human microflora, one of many such in nature, and that disruption of oral microbial ecology, due primarily to diet texture changes, leads to gingivitis and periodontitis. These result in increased plaque accumulation, and particularly in increased interdental effective plaque thickness. The latter leads to alterations in plaque ecology, particularly increasing anaerobiosis, with resultant shifts in proportions of its constituent species. These shifts are responsible for the increased counts of, for example, Bacteroides gingivalis, Actinobacillus actinomycetemcomitans, Fusobacterium nucleatum, Wolinella recta, spirochaetes and others, associated with chronic periodontitis in its various forms. Measures to prevent or control chronic periodontitis should aim, not to eliminate plaque, which ignores ecology and would compromise host defence, but to restore the species distribution in plaque to that compatible with health.

Notes: Abstract. This case report of severe periodontitis concerns a young male patient with chronic idiopathic neutropenia seen between 1981 and 1983 by the School of Dental Medicine of Geneva and from 1984 to 1988 by the Eastman Dental Hospital of London. The patient was maintained by intermittent systemic antibiotics, subgingival chlorhexidine irrigation, conventional debridement, brushing, and wire-mesh and composite splinting of loose teeth. After leaving school, at the patient's express wish, the extreme downhill pattern of the periodontitis resulted in removal of affected teeth and overdenture construction. The extracted teeth and associated soft tissues were examined for relevant plaque and host response features. The intact morphotypes associated with the advancing front of the lesion were invariably Gram-negative or positive coccoid cells, or less commonly short rods, as in all documented forms of periodotitis. Connective tissue destruction was associated with a leucocyte accumulation comprising mainly polymorphonuclear neutrophils (PMN) and plasma cells. Both were observed degenerated more deeply than in routine adult periodontitis, including PMN lysosome loss and lymphocyte maturation within peripheral blood vessels. Only in one instance, one part of the superficial connective tissue of one block contained bacteria. It was concluded that the features of plaque and the lesion suggest a typical first line of defence response as in other forms of periodontitis. From the consideration of the 10 years clinical history of the patient, it is clear that non-surgical management is possible even in extreme cases, without any compromise of the patient's oral or systemic health, and in accord with the patient's wishes.

Notes: Abstract 2 strontium chloride hexahydrate-containing dentifrices (SCH), similar except for their respective abrasive systems, were compared in a 2–month randomised double-blind parallel clinical study to evaluate their comparative effectiveness in terms of cervical dentinal hypersensitivity. 2 groups of 20 subjects, each with cervical dentinal hypersensitivity, were evaluated for tactile sensitivity by Yeaple probe, air sensitivity using a dental air syringe and subjective perception of pain by means of a visual analogue scale. There was no difference between the dentifrices as regards reduction of cervical dentinal hypersensitivity at each time point. The response to both dentifrices was evident within 4 weeks of use and the degree of improvement increased throughout the 8–week study period. The results support the conclusion that changing the abrasive component of SCH dentifrices did not significantly increase or decrease the (desensitizing) activity of the original product.

Notes: Abstract The present study comprises an investigation of 7 different probe types, representing currently-marketed major designs (WHO-CPITN, Williams, Michigan), as well as available calibration systems (engraved, etched and painted markings). Width of markings, accuracy of calibration from probe tip, and tine diameter at the tip and at specified points along the tine were assessed, using a stereomicroscope at a magnification of × 40. Blind duplicate measurements of these probe tine characteristics were 100% reproducible to within 0.01 mm. There was an overall range in marking width from 0.00–1.13 mm. The best marking, in that it had no appreciable width and the highest accuracy, was the discrete transition between normal and engraved parts of probes with engraved bands. Mean inaccuracies of different probe sets varied from 0.06 to 0.22 mm. Probes from the same batch from the same production line could differ by more than 0.5 mm in calibration. Mean tip diameter ranged from 0.28 to 0.70 mm. It was concluded that probe tine diameter and calibration should be considered in addition to other variables of periodontal probing. Standardisation of tine characteristics and avoidance of the use of different types or batches in a single study should enhance the accuracy and reproducibility of periodontal probe-dependent measurements.

Notes: Abstract In this study, mycoplasma were enumerated in the gingival crevicular fluid (GCF) of gingivitis and periodontitis patients. GCF samples were obtained from the mesial (approximal) gingival crevice or periodontal pocket of the maxillary right first permanent molar. Samples were cultured anaerobically on a medium selective for mycoplasmas as well as on a non-selective medium to obtain a total anaerobic count. Mycoplasmas were present in the GCF of both gingivitis and periodontitis patients, but a greater % was obtained from the GCF of patients with periodontitis. The proportions of mycoplasma appeared to be independent of the disease activity as expressed by bleeding on probing (FBI), but to be related to probeable pocket depth, as shown by the higher %s in periodontitis than gingivitis for a given FBI. On the basis of an increased proportion in relation to disease severity, mycoplasmas would therefore appear to be amongst those micro-organisms associated with CIPD.

Notes: Abstract A redox dye, methylene blue, was compared with subgingival root surface debridement and sterile water in the treatment of adult periodontitis. Plaque and gingival indices, bleeding on probing, and microbiological samples were obtained at baseline, and at 1, 4, 8 and 12 weeks following treatment. All subjects had matched pockets in each of the 4 quadrants, of 5 mm or more. One treatment consisted of 0.1% methylene blue gel irrigated professionally at 0, 1 and 4 weeks, and by subjects at days in between up to 4 weeks, at chosen sites within a randomly selected quadrant (split-mouth design). A 2nd treatment was sterile water irrigation as above. A 3rd quadrant received subgingival debridement, and sites in the 4th received methylene blue incorporated into a slow-release device of a biodegradable collagen alginate vicryl composite. All sites showed improvements in clinical and microbiological parameters. However, no statistically significant differences between treatment types were found for clinical measurements. Although plaque index tended to increase after week 1, gingival index was reduced, as was the papilla bleeding index. Probing depth reductions were approximately 1.2 mm for all treatments. Microbiological variables showed an increase in cocci and a decrease in motile organisms for all groups, the latter reaching statistical significance for subgingival debridement. The reductions in spirochaetes were significant for subgingival debridement and methylene blue by slow-release. Culture demonstrated an increase in the aerobe:anaerobe ratio for all groups, which was statistically significant initially (weeks 1 and 4) for subgingival debridement. Methylene blue was also effective statistically in improving this ratio, both by irrigation and slow-release (week 4). Methylene blue also significantly reduced the numbers of black-pigmented anaerobes during the trial period, both by irrigation and slow–release, which sterile water and subgingival debridement failed to do. No serious adverse experiences were seen, however, significantly greater morbidity was associated with subgingival debridement. These results clearly demonstrate that in altering the microflora to one that is more compatible with periodontal health, methylene blue treatment is comparable, or even better, than the currently standard treatment of subgingival debridement, and is better tolerated.

Notes: Abstract. Subgingival plaque samples from 20 patients with chronic inflammatory periodontal disease were exposed to a commercial gel formulation containing 2 amine fluorides. The MIC of the gel for these samples ranged from 33 to 260 μ/ml with a modal value of 260 μ/ml. In each sample, the most resistant organisms (i.e., those organisms surviving at one doubling dilution below the MIC) were identified. 33 such organisms were isolated, of which 22 (67%) were strict anaerobes, and 25 (75%) were Gram negative. The 2 most frequent isolates were Bacteroides ruminicola ss. brevis and a Selenomonas species, neither of which is a recognised periodontopathogen. The gel had a rapid effect on the viability of the bacteria in the plaque samples, the 90% kill time being 17 min or less for 90% of the samples (range 〈5 to 71 min).

Notes: Abstract Part of the results of a study of subgingival plaque by darkground microscopy was used to investigate morphotype distribution at different levels within the periodontal pocket. Subgingival plaque was sampled at coronal, middle and apical levels from each of 28 approximal surfaces on 28 teeth extracted from 28 adults with untreated moderate to advanced penodontitis. Sample preparation and darkground microscopy were as described previously. The data recorded only the subgingival level at which the maximum count occurred for a given morphotype and subject. It was found that the maximum count of spirochaetes occurred most frequently at the apical level (p〈0.05) and the maximum count of‘others' at the coronal level (p〈0.05). Also, coccal counts showed a trend to increase the more apical the sample. Standardised darkground microscopy was able to show that the sampled subgingival level had a significant influence on plaque bacterial morphotype distribution, indicating the importance of accurate sampling of subgingival plaque at the most apical level.

Notes: Abstract Traditionally cervical dentinal sensitivity (CDS) has been evaluated mainly subjectively on the basis of the individual patient's subjective response, e.g., in the form of verbal rating and visual analogue scales and questionnaires. The stimuli used for evaluating this response can be grouped into 4 main categories: mechanical, chemical, electrical and thermal. This review of the literature, however, indicates that there are problems in evaluating patient subjective response to these various test stimuli used in the assessment and treatment of CDS. Opinions also vary as to the reliability of some of these methods of assessment, although recently, efforts have been made to develop controlled reproducible stimuli more suited to the evaluation of CDS. Currently no single method of eliciting and assessing CDS may be considered ideal. Further research is required to evaluate suitable methodology for the quantification of realistic test stimuli under controlled clinical conditions, whereby the subjective response may be objectively measured by the investigator.