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Introduction: Systemic chemotherapy is able to convert colorectal liver metastases (CRLM) that are initially unsuitable for local treatment into locally treatable disease. Surgical resection further improves survival in these patients. Our aim was to evaluate disease-free survival (DFS), overall survival, and morbidity for patients with CRLM treated with RFA following effective downstaging by chemotherapy, and to identify factors associated with recurrence and survival. Materials and methods: Included patients had liver-dominant CRLM initially unsuitable for local treatment but eligible for RFA or RFA with resection after downstaging by systemic chemotherapy. Chemotherapeutic regimens consisted predominantly of CapOx, with or without bevacizumab. Follow-up was conducted with PET-CT or thoraco-pelvic CT. Results: Fifty-one patients had a total of 325 CRLM (median = 7). Following chemotherapy, 183 lesions were still visible on CT (median = 3). Twenty-six patients were treated with RFA combined with resection. During surgery, 309 CRLM were retrieved on intraoperative ultrasound (median = 5). Median survival was 49 months and was associated with extrahepatic disease at time of presentation and recurrences after treatment. Estimated cumulative survival at 1, 3 and 4 years was 90, 63 and 45 %, respectively. Median DFS was 6 months. Twelve patients remained free of recurrence after a mean follow-up of 32.6 months. Conclusion: RFA of CRLM after conversion chemotherapy provides potential local control and a good overall survival. To prevent undertreatment, the involvement of a multidisciplinary team in follow-up imaging and assessment of local treatment possibilities after palliative chemotherapy for liver-dominant CRLM should always be considered. [ABSTRACT FROM AUTHOR]

Minimally invasive surgical techniques for gastric cancer are gaining more acceptance worldwide as an alternative to open resection. In order to assess the role of minimally invasive and open techniques in total gastrectomy for cancer, a systematic review and meta-analysis was performed. Articles comparing minimally invasive versus open total gastrectomy were reviewed, collected from the Medline, Embase, and Cochrane databases. Two different authors (JS and NW) independently selected and assessed the articles. Outcomes regarding operative results, postoperative recovery, morbidity, mortality, and oncological outcomes were analyzed. Statistical analysis portrayed the weighted mean difference (WMD) with a 95 % confidence interval and odds ratio (OR). Out of 1242 papers, 12 studies were selected, including a total of 1360 patients, of which 592 underwent minimally invasive total gastrectomy (MITG). Compared to open total gastrectomy (OTG), MITG showed a longer operation time (WMD: 48.06 min, P < 0.00001), less operative blood loss (WMD: −160.70 mL, P < 0.00001), faster postoperative recovery, measured as shorter time to first flatus (WMD −1.05 days, P < 0.00001), shorter length of hospital stay (WMD: −2.43 days, P = 0.0002), less postoperative complications (OR 0.66, P = 0.02), similar mortality rates (OR 0.60, P = 0.52), and similar rates in lymph node yield (WMD −2.30, P = 0.06). Minimally invasive total gastrectomy showed faster postoperative recovery and less postoperative complications, whereas completeness of the resection was similar in both groups. Duration of surgery was longer in the minimally invasive group. Only comparative non-randomized studies were available, further emphasizing the need for a prospective randomized trial comparing MITG and OTG. [ABSTRACT FROM AUTHOR]

High throughput experimentation in catalysis and materials science has evolved into a mature technology platform. This article provides a technology-focused mini-review of three specific exemplary highlights, such as the purification of heavy feedstocks via hydroprocessing, the debottlenecking of workflows by smart use of alternative technologies, and the development of new mass screening devices. The approaches presented here clearly demonstrate their specific potential for accelerating research and show what level of sophistication has been reached since the early beginnings. [ABSTRACT FROM AUTHOR]

Abstract: Background: Interference in everyday functioning is part of the diagnostic criteria for dementia. Questionnaires measuring “instrumental activities of daily living” (IADL) are used to measure this interference, but the psychometric quality of these questionnaires is often questioned. In addition, these questionnaires are less suited for early-onset patients. This is problematic, given the high frequency of relatively young patients in memory clinics. In this article, we describe the development and psychometric properties of a new informant-based IADL questionnaire aimed at detecting incipient dementia and appropriate for a broad age range. Methods: We defined IADL in consensus with experts and constructed items based on existing items and suggestions from experts and informants. Informants of subjects (n = 206) who visited the Alzheimer Center of the VU University Medical Center completed the questionnaire. Factor structure was investigated using classical exploratory factor analysis and item response theory. We assessed test–retest reliability in 73 informants using weighted κ values. Results: The questionnaire consisted of 75 items and was computerized to enhance ease of administration. Exploratory factor analysis supported a single-factor model, with 48.3% of the variance being explained by the first factor. We removed five items, as they did not fit the model. High internal consistency was demonstrated. Test–retest reliability showed that the majority of items (87.9%) had substantial-to-almost perfect κ values. Conclusion: The Amsterdam IADL Questionnaire (Amsterdam IADL questionnaire is a registered trademark of Alzheimer Center VU University Medical Center, Amsterdam, The Netherlands) is a 70-item informant-based computerized questionnaire aimed at detecting early dementia and early-onset dementia. Initial results show that this questionnaire is a promising new tool. [Copyright &y& Elsevier]

Objectives To investigate whether problems in instrumental activities of daily living ( IADL) can add to conventionally used clinical measurements in helping to predict a diagnosis of dementia at 1- and 2-year follow-up. Design Multicenter prospective cohort study. Setting Memory clinics in Europe. Participants Individuals aged 55 and older without dementia. Measurements IADLs were measured using pooled activities from five informant-based questionnaires. Structural equation modeling ( SEM) was used to investigate the relation between IADLs and dementia. Age, sex, education, depression, and cognitive measures (Mini-Mental State Examination and verbal memory) were included in the model. Results Five hundred thirty-one participants had baseline and 1-year follow-up assessments; 69 (13.0%) of these had developed dementia at 1-year follow-up. At 2-year follow-up, 481 participants were seen, of whom 100 (20.8%) had developed dementia. Participants with IADL disabilities at baseline had a higher conversion rate (24.4%) than participants without IADL disabilities (16.7%) (chi-square = 4.28, degrees of freedom = 1, P = .04). SEM showed that IADL disability could help predict dementia in addition to the measured variables at 1-year follow-up (odds ratio ( OR) = 2.20, 95% confidence interval ( CI) = 1.51-3.13) and 2-year follow-up ( OR = 2.11, 95% CI = 1.33-3.33). Conclusion IADL disability is a useful addition to the diagnostic process in a memory clinic setting, indicating who is at higher risk of developing dementia at 1- and 2-year follow-up. [ABSTRACT FROM AUTHOR]

BACKGROUND: The hypothesis was tested that bacterial susceptibilities in aggressive periodontitis change upon administration of systemic antibiotics as adjuncts to periodontal therapy. METHODS: In 23 subjects (average age 38.9+/-6.7 years) with aggressive periodontitis, microbial parameters were assessed prior to and 1 year after completion of comprehensive mechanical/surgical and systemic antimicrobial therapy. Following identification of five selected pathogens with the Rapid ID 32 A system, their susceptibilities towards amoxicillin/clavulanate potassium, metronidazole, and tetracycline were examined with the E-test. Antibiotics were administered according to the test results, and the minimal inhibitory concentrations (MIC90) were reevaluated after 1 year. Statistical analysis was performed on a patient basis, with the site data used for evaluation of the MIC levels. RESULTS: Bacterial MIC levels remained constant among the three antibiotic treatment groups compared with baseline. Mean MIC90 values ranged from <0.02 to 0.11 microg/ml (amoxicillin/clavulanate potassium), <0.02 to 0.27 microg/ml (metronidazole), and <0.02 to 0.11 microg/ml (tetracycline). Observed changes in susceptibility were attributed to the elimination of single bacterial taxa in the subgingival environment after antibiotic therapy. There were no statistically significant differences in clinical parameters among the treatment groups. Single tetracycline MICs were 1.5- to 6-fold enhanced compared to amoxicillin/clavulanate potassium and metronidazole. CONCLUSION: The periodontal pathogens investigated prior to and 1 year after periodontal therapy are tested sensitive to the antimicrobial agents. In aggressive periodontitis, changes in bacterial susceptibility upon the administration of systemic antibiotics are associated with the limited number of isolates tested following therapy. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Instrumental Activities of Daily Living in the Screening of Dementia in Population Studies: Comment on Castilla-Rilo," in a 2007 issue of the journal.

Background: In patients with periodontitis, a quantitative prognostic assessment is needed in order to make evidence-based decisions about retaining teeth or extracting and replacing them with a dental prosthesis., Methods: One hundred and ninety eight patients receiving active periodontal treatment in 1989 or 1990 and complying with supportive periodontal therapy (SPT) over an average of 11.8+/-2.3 years were included in the study. A generalized linear model was established and fitted via generalized estimating equations to identify predictors for tooth loss during SPT., Results: Of the 4559 teeth present at baseline, 166 (3.6%) were extracted during active treatment and 249 (5.5%) during SPT. Baseline findings of diabetes mellitus (OR=4.17), reduced alveolar bone levels (OR=1.04 for each 1% increment), increased tooth mobility (III versus 0: OR=5.52), multiple roots (OR=1.82), and non-vital pulp (OR=2.24) were significant (p<0.05) predictors for tooth loss during SPT. Based on these parameters, a prognostic model was constructed that provides estimates of tooth survival probability when periodontal therapy is rendered., Conclusion: Using a multivariate approach, a prognostic model was developed that may be of value for clinical decision making.

Objectives: In the present trial, the hypothesis was examined that the local PMN responses in untreated and treated chronic periodontitis can be differentiated by gingival crevicular fluid lysosomal enzyme activities and elastase-alpha-1-proteinase inhibitor complex., Methods: In nine subjects (average age 49.2 +/- 7.1 years) with chronic periodontitis, clinical parameters and markers of the PMN-derived inflammatory tissue response in gingival crevicular fluid (GCF) were assessed before and 6 months after surgical periodontal therapy. Myeloperoxidase (MPO), beta-N-acetyl-hexosaminidase (beta-NAH) and cathepsin D (CD) were analyzed as indicators of the PMN-associated host tissue destruction, and elastase-alpha-1-proteinase inhibitor complex (alpha-1-EPI) as the major serum protein inactivating PMN elastase. The total activities of the lysosomal enzymes MPO and beta-NAH were evaluated spectrophotometrically, the CD levels by liquid scintillation counting with [14C] hemoglobin as substrate, and the total alpha-1-proteinase inhibitor complex using a sandwich-immunoassay., Results: The clinical parameters revealed a statistical significant decrease at the 6-month reexamination. PD levels dropped from 5.40 to 2.88 mm (change 2.52 +/- 1.04 mm), the CAL scores from 6.67 to 4.43 mm (change 2.24 +/- 0.77 mm). The 30 s GCF volumes dropped from 129.8 to 68.6, displaying a change of 61.1 +/- 18.6, p

Objectives: In the present prospective trial, the PMN response following resorbable GTR barrier placement was evaluated in mandibular class II furcation lesions., Materials and Methods: In 10 patients with treated chronic periodontitis, we randomly selected the 1st molars in the mandible with buccal degree II furcation involvement for either polylactic-citric-acid-ester (PLA) or glycolide-lactic-copolymer (PGL) GTR membrane therapy. We examined contralateral healthy molar sites as untreated controls. We then evaluated the PMN-derived inflammatory tissue response at baseline, weekly up to 6 weeks post-therapy and at 12 and 24 weeks using GCF myeloperoxidase (MPO), beta-glucuronidase (betaG) and beta-N-acetyl-hexosaminidase (betaNAH)., Results: The enzyme levels increased from baseline to the 6-week examination. After the 6-week reappointment, enzyme levels dropped reaching the baseline scores at both the 12- and 24-week visit. At PGL sites, the enzyme levels decreased earlier. Compared with healthy control sites, the MPO, betaNAH and betaG tests revealed different maximum levels at week 2 and 3 (PGL) and week 4, 5 and 6 (PLA). For both of the barriers the clinical parameters revealed a sustained improvement following therapy., Conclusion: The release of PMN enzymes following placement of bioabsorbable membranes reflects the early soft tissue healing process. Our results suggest that the PMN response is barrier-dependent with the maximum response occuring at different times. However, the host response did not measureably affect the course of clinical healing.

Background, Aims: Between 4 and 8% of periodontitis patients are reported to respond poorly to conventional therapy. In these cases, adjunctive use of systemic antibiotics might be a reasonable therapeutic approach. The purpose of this study was to evaluate the effects of systemic amoxicillin/clavulanate as adjunct to periodontal surgery on the predominant subgingival microorganisms in patients not responding to mechanical therapy. Furthermore, the bacterial susceptibility to amoxicillin/clavulanate was analyzed before and after therapy in order to assess the clinical validity of pre-therapeutic susceptibility testing., Methods: In 10 periodontitis subjects with no subgingival detection of Actinobacillus actinomycetemcomitans, the predominant subgingival organisms were identified using the identification system Rapid ID 32 A as well as antibiotic susceptibility was tested utilizing the E test., Results: Porphyromonas gingivalis and Prevotella oralis were detected in 7/10 subjects and could no more recovered after therapy. Fusobacterium nucleatum and Peptostreptococcus micros were present in 5/10 patients before treatment, but could be detected in 6/10, resp. 3/10 after therapy. In 4/10 subjects harboring F. nucleatum and in 3/10 with P. micros, those organisms were not targeted by amoxicillin/clavulanate, although post-treatment testing revealed their alleged susceptibility (MICs varied from 0.023 to 0.032 microg/ml, resp. from 0.125 to 2.0 microg/ ml)., Conclusions: The results of this study suggest that the outcomes of conventional methods of susceptibility testing have to be interpreted very carefully when being used for treatment of plaque-related diseases. Furthermore, since the endpoint of systemic antibiotic treatment as adjunct to conventional therapy is elimination of F. nucleatum or P. micros in patients harboring these organisms, the use of amoxicillin/clavulanate appears not to be justified.

A. actinomycetemcomitans (Aa) can be transmitted among family members. The purpose of the present study was, to evaluate, whether A. actinomycetemcomitans is able to persist for a prolonged period of time in periodontally healthy subjects following elimination of this pathogen from diseased family members. In 14 periodontitis patients harboring Aa as well as in their 37 family members, the clinical (PPD, PAL, P1I, GI) and microbiological status (TSBV) was evaluated. After study patients received mechanical, surgical and antibiotic (3x375 mg amoxicillin+3x250 mg metronidazole/7 d) treatment, they, as well as their family members, were reassessed 3, 6, 9 and 12 months following therapy. From 13 spouses, 4 (31%) had periodontitis associated with Aa, 4 (31%) had periodontitis and no Aa, 2 (15%) were periodontally healthy and harbored Aa, 3 (23%) were healthy with no detection of Aa. From 24 off-springs, one (4%) had periodontitis associated with Aa, 8 (33%) were healthy and harbored Aa, 15 (63%) were healthy with no detection of Aa. In the 2 spouses and in 7 of the 8 offsprings being healthy, but harboring Aa, this pathogen still persisted at the 12-month appointment, after it had been eliminated from the diseased family members. Only one child became negative for Aa after 12 months. The results of this study indicate that A. actinomycetemcomitans is able to persist in the oral habitats of periodontally-healthy subjects for at least 12 months, after this pathogen had been eliminated from diseased family members. This might suggest that also in healthy family members, A. actinomycetemcomitans as a source of transmission should be eliminated to prevent reinfection.

In the present study, the antibiotic susceptibility of most prevalent micro-organisms in advanced periodontitis patients was evaluated. In 56 patients, pooled subgingival plaque samples were taken from the deepest site of each quadrant and were cultivated anaerobically. From each patient, the 4 most frequently encountered types of bacterial colonies were subcultured and identified (Rapid ID 32 A). From all bacterial species identified in the 224 subcultures, the 4 most prevalent were used for susceptibility testing to tetracycline, metronidazole and amoxicillin/clavulanate using the E Test. The most prevalent microorganisms were Fusobacterium nucleatum (38/214), Peptostreptococcus micros (33/214), Prevotella oralis (33/214) and Porphyromonas gingivalis (32/214). Regarding antibiotic susceptibility it could be shown that minimal inhibitory concentration (MIC) in all cases was below antibiotic concentrations achievable in gingival crevicular fluid. However, antibiotic resistance was seen in 3 to 29% of the investigated microorganisms.

The following communication is a case history of an 11 year-old female patient suffering from Papillon-Lefèvre syndrome. Since a massive occurrence of A. actinomycetemcomitans had been found in the subgingival microflora of the periodontal pockets, the patient was treated with repeated subgingival scaling, with an adjunct Amoxicillin and Metronidazol treatment. A bacteriological examination of the girl's family proved that several brothers and sisters as well as one parent also carried. A. actinomycetemcomitans, showing 3 different strains of this bacterium within the family. An immunohistological examination of the gingival tissue showed a massive inflammatory infiltrate which was dominated by plasma cells. The histological investigation of the first molars did not show morphological abnormalities of the root cementum. Posttreatment clinical and radiographical improvement of the periodontal conditions is reported despite the recurrent finding of A. actinomycetemcomitans.

In the present study, data from more than 550 periodontally diseased patients with more than 1100 furcation invasions were retrospectively analysed. There were apparent differences in the distribution of different furcation degrees in patient populations treated by 2 differently experienced operators. However, treatment modality patterns were rather similar. Scaling during periodontal flap surgery was the most often performed treatment procedure in degree I (97-98%) and II (75-83%) involvements. About 44% of degree III involved teeth were extracted. In order to determine the influence of degree of furcation involvement, tooth type and operator variability on treatment modality, logistic regression analysis was applied. Degree of furcation involvement was an important indicator variable in all models. Scaling as a sole measure was mainly performed in relation to degree I of furcation involvement. With every increase in degree, the odds of scaling decreased by factor 12.7. The odds of root resection was upper 1st molars 46 x higher than in wisdom teeth or lower 2nd molars with the same degree of involvement, but only 3.3 x higher than in lower 1st molars. Tunnel preparation as well as regenerative procedures were mainly confirmed to lower molars. Operator variability was only introduced as a covariate in the extraction model. hence, despite of different operator skill and severity of periodontal disease in treated populations, decision for one or the other treatment modality seems to depend essentially on degree of furcation involvement as well as tooth type.

In the present study, a total of 619 subgingival and extracrevicular samples from 66 early-onset periodontitis, 42 adult periodontitis/gingivitis and 36 treated Actinobacillus actinomycetemcomitans-associated periodontitis patients were selectively cultivated for presence of A. actinomycetemcomitans. The organism was recovered from 68% cases with early-onset periodontitis, 24% cases with adult periodontitis/gingivitis and 50% of treated patients. Associations between recovery from pooled subgingival plaque and samples from extracrevicular locations as well as between different extracrevicular samples, were not heterogeneous with regard to different groups with the exception for cheek/saliva comparisons (odds ratios: early-onset periodontitis 825; adult periodontitis 8.1; treated patients 117; 0.05 < p < 0.1). For associations between recovery of A. actinomycetemcomitans from pooled subgingival plaque/extracrevicular samples, Mantel-Haenszel's odds ratios of between 12.2 and 21.6 were calculated (p < 0.0001). The organism was isolated from 17 cheek mucosa samples of 18 patients identified as still harboring the organism after therapy. Present results point to the considerable value of cheek mucosa samples especially in treated patients to diagnose persistent A. actinomycetemcomitans colonization of the oral cavity.

In the present study, recall data of 29 patients with advanced periodontitis were utilized to calculate diagnostic test parameters for bleeding scores or increased residual probing depth on increase of periodontal probing depth of > or = 2 mm after 2 years, comparing the simple binomial and correlated binomial model. 5.6% of sites were identified, where the periodontal probing depth increased 2 mm or more during 2 years of maintenance. Within-patient correlation coefficient of sites were found to be small, in general (p < 0.02), with the exceptions for predictive value of a positive test for frequent (> or = 3/4 times) bleeding on probing and residual probing depth of > or = 4 mm (p = 0.137 and p = 0.086, respectively), and specificity for no bleeding (p = 0.151). Point estimates of test parameters generally did not differ between simple binomial and correlated binomial model. The respective standard deviations were either over- or underestimated in the simple binomial model. It was concluded that the suggestion of a limited diagnostic value of bleeding scores or increased residual postoperative probing depth to predict recurrence of periodontitis cannot be rejected after application of a correlated binomial model.

Frequent bleeding on probing (BOP) has been considered a risk factor for recurrence of periodontitis. In the present study, 29 patients with Actinobacillus actinomycetemcomitans-associated periodontitis were enrolled in a carefully performed recall system. At 6 sites per tooth, periodontal probing depth (PPD), gingival index (GI), plaque index (PlI) and BOP was assessed 6 weeks, 6 months, 1 and 2 years after comprehensive therapy. Professional toothcleaning and subgingival scaling at sites with PPD > or = 5 mm and BOP was carried out every 2nd or 3rd month. Subgingival samples from 2 sites, a pooled subgingival sample, cheek mucosa, saliva and tongue samples were selectively cultivated for A. actinomycetemcomitans after 2 years. Following active therapy, 8% sites had a PPD of > or = 4 mm, whereas 21% sites bled on probing. After 2 years, respective figures were 12 and 27%. During maintenance, frequent BOP (> or = 3 times at 4 visits) had a predictive value of 0.133 to indicate an increase in PPD of > or = 2 mm and a negative predictive value of 0.947. The predictive value of no bleeding to indicate a stable site was 0.972, the negative predictive value 0.078. There was evidence for heterogeneity of associations between increase in PPD of > or = 2 mm and > or = 3 times BOP among patients (chi 2(28) = 41.45, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Considerable problems have been reported in the eradication of Actinobacillus actinomycetemcomitans from periodontal sites. The present communication describes the 2-year results of a comprehensive combined mechanical/surgical and adjunctive minocycline (200 mg/day for 3 and another 2 weeks) treatment regimen in 28 patients with A. actinomycetemcomitans-associated periodontitis. Elimination of A. actinomycetemcomitans at periodontal sites was a prerequisite for gain of clinical attachment of > or = 2 mm or decrease of probing depth to < or = 4 mm after subgingival scaling plus minocycline (p < 0.01). Whereas 2 years after active treatment A. actinomycetemcomitans could not be detected at monitored sites in 23 patients, the organism was found on buccal mucosa and in saliva in 17 and 12 cases, respectively. One or 2 years after periodontal surgery, there was a significant association between log10-numbers of A. actinomycetemcomitans in buccal samples and numbers of residual pockets of > or = 7 mm as well as gingival sites with overt gingivitis (R2 = 0.687, p < 0.001). Present results indicate failure of an even prolonged administration of adjunctive minocycline to eliminate oral A. actinomycetemcomitans in most cases of A. actinomycetemcomitans-associated periodontitis.

Infrequent occurrence of spirochetes and rather low proportions of these organisms have been reported in localized juvenile periodontitis, where periodontal lesions often harbour large numbers of Actinobacillus actinomycetemcomitans, a suspected principal periopathogen strongly implicated in the pathogenesis of this and other forms of chronic periodontitis. We studied the association of subgingival A. actinomycetemcomitans with the morphological composition of the subgingival microbiota in a large population of patients suffering from advanced periodontitis. Subgingival plaque from the deepest pockets of every quadrant of their dentitions was sampled and pooled in 70 patients between 14 and 63 years of age, and analysed morphologically by phase-contrast microscopy. A minimum % similarity index was employed to define 4 clusters with different morphological composition of the floras. The actual proportion of A. actinomycetemcomitans was determined at 2 sites with deep periodontal pockets. All clusters harboured patients infected with A. actinomycetemcomitans. If present, in clusters predominated by motile rods or medium-sized spirochetes, the organism was found in rather low proportions (median 5.3% and 3.4%, respectively). However, the cluster with a pooled flora mainly consisting of coccoid cells revealed periodontal sites with A. actinomycetemcomitans in proportions of more than 53% (median), if the organism was present (p less than 0.01). We found a positive correlation between proportions of A. actinomycetemcomitans and cocci (R = 0.65) and negative correlations with spirochetes and motile rods (R = 0.61, R = -0.59, respectively). Cautious interpretation of subgingival plaque predominated by coccoid cells is recommended, if deep periodontal pockets and obvious signs of inflammation are present, since these pockets were found to be often infected with large numbers of A. actinomycetemcomitans.

Multiple periodontal abscesses were reported in medically compromised patients. We examined patients with a non-contributory medical history referred for the treatment of numerous periodontal abscesses. All patients had taken oral broad spectrum antibiotics 1 to 3 weeks prior to the outburst of the abscesses (8 patients: penicillin, 2 patients: tetracycline). The patients suffered from advanced periodontal disease, 82% of the examined sites showed probing depths greater than 3 mm, 56% attachment loss greater than 3 mm. Subgingival plaque samples were analysed from 2 different abscess sites. Bacteroides gingivalis (19/20), Fusobacterium nucleatum (13/20) and Streptococcus intermedius (13/20) were the most prevalent anaerobic microbiota. Strains resistant to the prescribed antibiotic were found in 55% (11/20) of the subgingival plaque samples. It was concluded that in patients with advanced periodontal disease, systemic antibiotic therapy without subgingival debridement may change the composition of the subgingival microbiota, thus favouring the outburst of multiple periodontal abscesses.

The purpose of the present study was to investigate whether functionally different macrophages are present in clinically healthy gingiva and during human experimental gingivitis. Eight male probands were introduced to an oral hygiene program until all reached mean Plaque and Gingival Index scores approaching zero. During the following 19 days all oral hygiene was abandoned. At d -14, 0, 2, 4, 7, 11 and 19 clinical indices and gingival biopsies were taken. Cryostat sections were incubated with monoclonal antibodies against mature macrophages (25F9), inflammatory macrophages (27E10) and anti-inflammatory macrophages (RM 3/1). Positive cells were counted in the inflammatory infiltrate (IF) and the connective tissue (CT). At d -14 elevated numbers of 27E10-positive cells were observed which decreased significantly at d 0 (p less than 0.018) and increased again at d 19 (p less than 0.026). Significant differences in the number of RM 3/1-positive cells were found between d 0 and d -14, 2, 4 and 7 (p less than 0.05) while no differences in the number of 25F9-positive cells were observed throughout this study. It was concluded that experimental gingival inflammation is characterized by the appearance and disappearance of functionally different macrophage subpopulations.

The main ecological niche of Actinobacillus actinomycetemcomitans (A.a.) seems to be the periodontal pocket, but it can also be isolated from supragingival plaque, buccal and tongue mucosa, or saliva. We examined toothbrushes from 21 patients, all identified as harbouring moderate to large numbers of A.a. in subgingival plaque, for contamination with this organism. 29% of the toothbrushes presented by our patients yielded detectable numbers of A.a. Immediately after toothbrushing this figure rose to 62%, but dropped to 50% after 1 h. Numbers of isolated A.a. on toothbrushes were weakly correlated with the degree of periodontal destruction, and significantly more numbers of A.a. on toothbrushes could be detected if the organism was found on mucous membranes or in saliva. There was no association with gingival inflammation, supragingival plaque nor mean numbers of isolated subgingival A.a.