Notes: The decay of Escherichia coli in a sandy loam soil, amended with enhanced and conventionally treated biosolids, was investigated in a field experiment following spring and autumn applications of sewage sludge. Control soils, without the application of biosolids, were also examined to determine the background indigenous populations of E. coli which are present in the environment. The survival of indigenous E coli and populations of E coli applied to soil in biosolids, is assessed in relation to environmental factors influencing pathogen-decay processes in soil.

Notes: Abstract It is generally believed that Supragingival plaque control has little effect on the subgingival micro flora of deep periodontal pockets. However, this may not be true for moderately deep pockets (4–5 mm), which may represent a pathological state between gingivitis and marginal periodontitis. In 6 patients with poor oral hygiene and severe gingival inflammation, 4 matched sites (1 in each quadrant), were chosen which demonstrated at least 20% spirochetes and 15% black-pigmented Gram-negative bacilli. During the first 12 weeks (phase 1), Supragingival calculus was removed from the right half of the mouth and then the teeth were professionally cleaned three times a week. At the beginning of phase 2, Supragingival calculus was also removed from the left quadrants and the entire mouth was subjected to the same protocol used in phase 1. At no time did patients receive oral hygiene instructions. Clinical parameters were assessed and microbiological samples were taken at 3-week intervals. Samples were submitted to darkfield microscopy and anaerobic culturing. Analysis by multiple linear regression and the Wilcoxon signed-rank test revealed significant changes in the composition of the subgingival microbiota at cleaned sites. While Gram-positive organisms increased proportionally, a number of putative periodontal pathogens, such as P. gingivalis and spirochetes decreased.

Notes: Abstract The present study was designed to determine the threshold pressure value to be applied in provoking bleeding on probing (BOP) in clinically healthy gingival units. 12 female dental hygiene students volunteered for the study. They were selected on the basis of excellent oral hygiene standards, absence of probing depths 〉 3 mm and absence of caries or dental restorations on smooth and proximal tooth surfaces. Applying a probing force of 0.25, 0.5, 0.75 and 1.0 N in one of the 4 jaw quadrants, respectively, on 2 different occasions with an interval of 10 days, bleeding on probing was assessed. Oral hygiene and gingival conditions were determined using the criteria of the plaque control record and the gingival index. On the basis of the BOP values, obtained using the lowest probing force (0.25 N), the subjects were divided into 2 groups: group 1 (“minimal BOP” value) consisted of 6 subjects yielding practically no bleeding (mean BOP = 0.9%) at both examinations, while the subjects of group 2 (“low BOP” value) had slightly higher BOP% (mean BOP =13.4%). Both groups showed significant increase in mean BOP% with increasing probing force (0.9%-36.1% in group 1 and 13.4%-47.0% in group 2). Regression analysis revealed an almost linear correlation and a high correlation coefficient between BOP% and probing force. The comparison of the regression lines of the 2 groups showed almost identical slope inclination. However, slight differences in slope inclination were found for different sites: approximal sites clearly yielded steeper regression lines than buccal/oral sites. The results of the study demonstrated that the BOP test using uncontrolled forces may result in a proportion of false positive readings and that a strong possibility exists for the traumatization of clinically healthy gingival tissues if a probing force exceeding 0.25N is applied.

Notes: Abstract A clinical study was conducted among 200 adult males and females to compare the intrusive gingival index (GI) for estimating gingivitis with the non intrusive and only visually applied papillary-marginal-gingivitis index (PMGI). The GI examinations were performed by a senior examiner with long experience and a junior examiner, while the PMGI was graded by only a senior examiner with long experience. A 4th examiner was included for grading bleeding sites by gentle intrusion at the orifice of the gingival crevice. Following the baseline examination by all examiners, the subjects were randomly assigned to either a group that received an oral prophylaxis immediately or to a group that received an oral prophylaxis 6 weeks after the baseline. All subjects were regraded by all examiners 4 days after the 2nd group received a prophylaxis. This delayed prophylaxis design created a difference in the responses between treatment groups. Both the GI examiners and the PMGI examiner concluded there was significantly less gingivitis in the group receiving a prophylaxis second. There were also significantly fewer bleeding sites in the group receiving a prophylaxis second as determined by both GI examiners and the bleeding-sites examiner.

Notes: Abstract The aim of the present study was to investigate stereologically the histologic alterations occurring during gingival healing after experimental gingivitis and to compare clinical parameters with histological findings. 8 dental students volunteered for the investigation. After a prophylaxis, they performed optimal oral hygiene to reach mean plaque and gingival indices approaching zero. They then abolished all oral hygiene procedures for a period of 21 days. After this experimental gingivitis phase, they again performed optimal oral hygiene for 8 days to restore gingival health. At days 0. 1, 2, 4, and 8 after experimental gingivitis, the plaque index (PII), the gingival index (GI) and the gingival exudate flow rate (GEFR) were assessed and their buccal gingiva was biopsied. Point counting procedures were performed at 2 different levels of magnification on light microscopic sections to estimate the volume fractions of epithelium, infiltrated and non-infiltrated connective tissue, and collagen. The relative numbers of fibroblasts, polymorphonuclear neutrophils. lymphocytes, plasma cells and macrophages were estimated by counting the number of profiles of these cells in a specific connective tissue area adjacent to the apical end of the junctional epithelium. A rapid drop in the PII was noted with increasing time after oral hygiene, followed by a slower decrease in the GI and GEFR scores. The histological picture during the entire experiment was that of an initial gingival lesion. At day 0, no chronic inflammation of the gingiva characterized by a predominance of plasma cells was observed. After resumption of oral hygiene when the relative cell numbers at day 0 and day 8 were compared, only an increase in the PMN population was observed. As GI and GEFR scores decreased no significant changes were noted in the relative numbers of the various cell types. These observations suggest that the “physiogenesis during experimental health” appears first clinically and then histologically, and hence, it may take more than 8 days to observe significant variations in cell populations.

Notes: Abstract The purpose of this study was to determine the clinical response to local delivery of tetracycline in relation to clinical and microbiological conditions of the other teeth. 4 deep pockets were monitored in 19 subjects with multiple deep periodontal lesions and high counts of P. gingivalis. In 9 patients (XT) only 2 of the selected lesions were treated by placement of tetracycline fibers (Actisite®). while the rest of the dentition was left untreated. In the other 10 patients, all teeth were supragingivally scaled and then treated by application of polymeric tetracycline HCl containing fibers, the whole dentition was subject to full mouth scaling and root planing, and the patients rinsed with 0.2% chlorhexidine (FT). A significant reduction in mean PPD was observed in all treated sites after two months. This reduction was maintained over the following 4 months. The magnitude of the effect was significantly greater in the FT group (1.74 mm) than in the LT group (0.88 mm). The mean attachment level changes were similar after 2 months in locally and fully treated subjects. A tendency of relapse was noted for treated sites in LT patients from month 2 to 6. A level of statistical significance was not reached for this effect. Data from measurements recorded at 6 sites around all teeth in the full mouth treated patients were analyzed using multiple linear regression. This analysis showed local changes in PPD and AL were significantly and strongly correlated with the baseline value of the respective parameter at the same site. In addition, more pocket depth reduction was noted if a site was not bleeding on probing at 6 months, if the location of a site was not approximal and if the tooth was not a second molar. Sites located on second molars showed also less AL gain than sites located on other teeth. Smokers showed significantly less reduction in PPD and significantly less AL gain. Furthermore, if subjects had a high % of pockets deeper than 4 mm at baseline they showed significantly less attachment gain.

Notes: Abstract. The aims of the present study were to assess radiographically the effects of scaling/root planing combined with antibiotic therapy using tetracycline fibers (TCF): (II) on alveolar bone density and linear discriptors and (II) on supracrestal soft tissue density, 19 subjects with generalized adult periodontitis (with at least 20 teeth present, at least 4 teeth with pockets 〉4 mm and bleeding upon controlled force probing) and high cultural counts of Porphyromonas gingivalis were recruited from a pool of 57 patients. The full mouth treatment group (FT) consisted of 10 patients, who underwent a full mouth supra-gingival scaling and prophylaxis treatment and were instructed to rinse 2× daily with a 0.1% chlorhexidine solution. 1 week later, tetracycline-hydrochloride-containing fibers (Actisite® periodontal fiber) were applied around all teeth. After 7–12 days, the fibers were removed and all teeth were scaled and root planed under local anaesthesia. The chlorhexidine rinsing continued for another 2 months. In 9 subjects (local treatment group LT), 2 teeth with periodontal lesions with pocket probing pepth (PPD) ≥5 mm were treated by placement of tetracycline fibers, which remained in place for 7 to 12 days. Upon removal of the fibers, scaling and root planing was performed on these 2 teeth, while the rest of the dentition renamed untreated, and no chlorhexidine rinse was applied, 2 of the untreated teeth revealing similar periodontal lesions were chosen to represent sites affected by untreated periodontitis (NT). In this group, a limited local treatment was performed (2 teeth) with the inherent potential for recolonization from the untreated pocket sites. Standardized periapical radiographs were obtained from the 4 monitored sites within each patient at baseline (before treatment) and 2 and 6 months thereafter. One radiograph was exposed in a standard way for bone assessment. The second radiograph was underexposed, at about a 1/5 of the original exposure time to allow the evaluation of soft tissue. Mean changes in the near parameters and changes in density (CADIA) observed at multiple sites within each patient and treatment group were used as the best estimate of treatment outcome. Over the observation period of 6 months, a significant difference in bone height changes was found between the untreated sites (median loss –0.29 mm) and the sites from full-mouth treated patients (median gain 0.24 mm p=0.008). When comparing the baseline to the 6 months radiographs, a loss in bone density was observed for the untreated group (median=–2.13 CADIA), Both treatment groups revealed a gain in density (median= 1.58 and 2.43 CADIA for the locally and the full–mouth treated groups, respectively). Differences in density were significant, both between the nontreated and locally treated sites (p= 0.026) and between the nontreated sites and the sites from the full mouth treated patients (p=0.002). The analysis of the soft tissues showed a similar pattern of changes in density to those seen in the bone defect. At 2 months, there was a tendency for loss in density for the nontreated group (median=–0.17 CADIA) that continued over the 6 month period (median =–0.31 CADIA), A significant increase in density was observed for the full–mouth treated sites (median = 1.57 and 0.64 CADIA for the 2 and 6 months radiographs, respectively), A significant increase was also observed for the locally treated group when compared to the untreated sites (median=0.13 and 0.10 CADIA for the 2 and 6 months radiographs, respectively). Comparing untreated sites with full–mouth treated sites, a significant difference was observed for CADIA measurements (p〈0.001). No significant difference was observed comparing locally treated and untreated sites (p=0.24). It was concluded that scaling and root planing combined with TCF therapy can result in increased bone density and alveolar bone height. Full-mouth treatment seemed to result in more pronounced gains compared to local treatment. Untreated sites continued to lose alveolar bone height and density, CADIA of supracrestal soft tissue ROI paralleled the remodelling observed in bone ROI, This is the first controlled study revealing that CADIA of soft tissue ROI in series of underexposed standardized radiographs may render additional valuable information on remodelling of periodontal tissues after therapy.

Notes: Abstract The purpose of the present investigation was to study the topographical distribution of plaque formation using chlorhexidine digluconate (CH) as a mouthrinse and in oral irrigators during experimental gingivitis.Forty dental students (aged 22–26) with clean teeth and healthy gingivae abolished oral hygiene oral period of 3 weeks (Löe et al. 1965). During this period the participants were randomly assigned to one of five groups, Group A rinsed daily with 30 ml of a placebo and Group B with 30 ml 0.1% chlorhexidine digluconate. In Groups C and E a fractionated jet irrigator was used for the daily application of 600 ml placebo (C) or O.05% CH (E); 600 ml of 0.05% CH was also used in a monojet irrigator (Group D). At the start, after 1, 2 and 3 weeks of no oral hygiene and 1 week following reinstituted oral hygiene, plaque was assessed using the Plaque Index (Silness &. Löe 1964) and gingival health was scored according to the criteria of the Gingival Index (Löe & Silness 1963). The discoloration of the teeth was determined using a set of color photos.During the experiment all groups reached plaque levels that were significantly different from each other. The highest PII were seen in the placebo rinsing group (A) followed by placebo irrigation (C). Plaque was significantly reduced in the CH groups. However, rinsing (B) formed significantly more plaque than using the oral irrigator (D, E). Group E showed the least amount of plaque. In addition, the interproximal PII were equally low as the buccal and lingual. With CH (B, D, E), gingivitis did not develop except for some interproximals in Group B. A fractionated jet irrigator was more effective for the application of CH than rinsing.

Notes: Abstract. The aim of the present study was to assess the influence of a 1-month period of chlorhexidine digluconate (CHX) rinses on the remodelling activity of periodontal tissues adjacent to an extraction wound. From 12 patients assigned to the test group rinsing 2 × daily with 15 ml of 0.12% CHX solution (Peridex®) starting 2 days after tooth extraction and from 11 patients assigned to the control group rinsing with a placebo solution, standardized radiographs were available taken immediately after tooth extraction and 1, 2, 3 and 6 months thereafter. Computer assisted densitometric image analysis (CADIA) was applied in order to quantify changes in density during the healing phase after tooth extraction. Regions of interest (ROI) were chosen for CADIA covering supracrestal periodontal soft tissue adjacent to the extraction wound. ROIs were also defined on crestal alveolar bone adjacent to the extraction wound. In the active group, 15/20 sites demonstrated an increase in alveolar bone density between months 1 and 6 (mean CADIA value 6.7 ± 10.0), whereas in the control group 11/21 sites demonstrated a loss in density (mean CADIA values -1.4 ± 10.5). Similar observations were made when the ROIs covering supracrestal periodontal tissues were analyzed (mean CADIA values 7.8 ± 8.4 for the experimental group and –0.3 ± 10.5 for the control group). These differences were statistically significant (p 〈 0.04). The digitized series of standardized radiographs were also evaluated for changes in bone height. The distances from the alveolar bone crest to reference points were measured in mm within the baseline: the 1, 2, 3 and 6 month radiographs. Whereas the control group rinsing with a placebo solution lost almost 1 mm of bone height over 6 months after tooth extraction, it was obvious that in the patients rinsing with the CHX solution, the crestal alveolar bone level was maintained. It was concluded that the administration of 0.12% chlorhexidine rinses for 1 month following tooth extraction resulted in a beneficial healing effect on the periodontal conditions of teeth adjacent to the extraction site.

Notes: Abstract. The aim of the present study was to evaluate periodontal tissue alterations during the maintenance phase following GTR therapy. 18 patients (average age 54 years, range 39–79 years) with 19 local periodontal defects were monitored longitudinally using clinical periodontal parameters and radiographic assessments of bone level changes. 6 out of originally 24 patients were not available at the 4-year examination (2 patients were unwilling to participate and in 4 patients root amputations or tooth extractions had to be performed). Evaluations were perfomed at baseline. 3 months, 1 year and 4 years following GTR therapy (using non-resorbable Gore-Tex® Periodontal Material). The changes observed at the deepest site of each tooth treated by GTR were compared to those encountered in the entire dentition. Supportive periodontal therapy was performed according to the patient's individual needs between 3 and 12 times between the 1 and 4 years examination. The plaque index and the gingival index at the 4 years examination were assessed and had increased to almost double the value of baseline, although the BOP remained lower compared to baseline data. Between the 1 and 4 years examinations, 1.27 mm of clinical attachment was lost as a mean. Regarding the site of each tooth treated with GTR with the initially deepest probing pocket depth, 1.42 mm of clinical attachment was lost during the maintenace phase. However, compared to baseline data, 1.37 mm of new attachment could be maintained. The clinical attachment level was maintained within ±1 mm in 12 out of 19 sites during the 4 years of maintenance. At 7 sites, a loss between 2 and 5 mm occurred during the maintenance phase. Compared to the baseline values, 4 sites had lost ≥2 mm of clinical attachment resulting in a net loss. Between the 1 and 4 years observation, no significant change in bone height was observed. Multiple regression analyses showed correlations between the maintenance of the new attachment (expressed as change in probing attachment level) and a combination of factors such as number of recall visits during maintenance phase, age of the patient and % of loser sites in the corresponding dentitions. It was concluded that a low incidence of gingival inflammation was a. prerequisite for the maintenance of attachment levels gained by the GTR technique.