Estrogen regulates DNA synthesis in human gingival epithelial cells displaying strong estrogen receptor ß immunoreactivity.

BACKGROUND AND OBJECTIVE: Estrogen acts via estrogen receptor (ER) α and ß. The expression pattern of ERs and their importance in gingival tissues are not fully understood. In this study, we investigate gingival ER expression and effects of estrogen on gingival epithelial cell proliferation. MATERIAL AND METHODS: Gingival biopsies were obtained from both healthy and diseased sites in three male and three female subjects. Expression of ERα and ß was determined by immunohistochemistry. Effects of 17ß-estradiol (E(2) ) on cell proliferation, monitored by measuring DNA synthesis, were studied in cultured human gingival epithelial HGEPp.05 cells. RESULTS: Estrogen receptor ß, but not ERα, immunoreactivity was demonstrated in nuclei of epithelial cells in all layers of the gingival epithelium, but also in cells of the lamina propria. No differences were observed between male and female subjects. The same pattern, i.e. high ERß expression but no ERα expression, was observed in both healthy and diseased sites within each individual. No differences in the intensity of the ERß immunoreactive signal and the number of ERß-positive nuclei were observed between healthy and diseased gingiva. Treatment with a physiological concentration of E(2) (10 nm) had no effect on DNA synthesis in ERß- and ERα-expressing HGEPp.05 cells. In contrast, E(2) at high concentrations (500 nm and 10 µm) reduced DNA synthesis by 60-70%. CONCLUSION: Human gingival epithelial cells display strong ERß but low ERα immunoreactivity both in vivo and in culture. Estrogen attenuates gingival epithelial cell DNA synthesis at high but not low concentrations, suggesting a concentration-dependent mechanism.

Differential regulation of chemokine expression by estrogen in human periodontal ligament cells.

BACKGROUND AND OBJECTIVE: Estrogen modulates inflammatory responses, but the mechanisms involved have not yet been identified. Periodontal ligament (PDL) cells produce chemokines (a group of chemoattractant molecules that recruit leukocytes) and it has been suggested that estrogen modulates periodontal inflammation by regulating the expression of chemokines by PDL cells. Therefore, the objectives of this study were to investigate the regulation of chemokine ligand 2 [CCL2/monocyte chemoattractant protein 1 (MCP-1)], chemokine ligand 3 [CCL3/macrophage inflammatory protein-1α (MIP-1α)] and chemokine ligand 5 (CCL5/RANTES) by estrogen in human PDL cells. MATERIAL AND METHODS: PDL cells were obtained from the PDL of premolars, extracted for orthodontic reasons, from two boys and two girls (16 and 17 years of age). PDL cell CCL2, CCL3 and CCL5 mRNA transcripts were determined by quantitative real-time PCR. The concentrations of CCL2, CCL3 and CCL5 proteins were determined by ELISAs. RESULTS: Treatment with 0.5 µg/mL of lipopolysaccharide (LPS, from Escherichia coli) + 100 nm 17ß-estradiol (E(2) ) for 24 h reduced the expression of CCL3 mRNA by about 40% compared to PDL cells treated with LPS alone. Attenuation of CCL3 mRNA was not associated with a decrease in CCL3 protein within 48 h, suggesting a slow turnover of the CCL3 protein. Interindividual differences in the effects of E(2) on CCL5 mRNA expression were observed. E(2) (100 nm) increased the expression of CCL5 by 40-60% in PDL cells derived from two subjects but reduced the expression of CCL5 by about 30% in cells from another subject. CCL2 mRNA and CCL2 protein were highly expressed, but not regulated by E(2) . Similar data were observed in cells obtained from both boys and girls. CONCLUSION: Regulation, by estrogen, of chemokine expression in PDL cells shows a complex pattern involving the down-regulation as well as the up-regulation of chemokines, suggesting that estrogen exerts both anti-inflammatory and proinflammatory effects through these mechanisms.

Comparison of ready-to-use EMDOGAIN-gel and EMDOGAIN in patients with chronic adult periodontitis.

OBJECTIVES: The aim of this multicenter trial was to compare the clinical and radiographical outcome of a ready-to-use Emdogain-gel (test) with the marketed Emdogain (control). METHODS: Subjects with bilateral infrabony defects > or =4 mm deep and > or =2 mm wide according to radiographs were selected. 88 subjects with probing pocket depth (PPD) > or =6 mm > or =1 month after supervised oral hygiene and scaling participated. At baseline plaque index, bleeding on probing, PPD and probing attachment level were recorded and reproducible radiographs for computer-based bone level measurements were taken. In each subject, 1 tooth was randomly treated with the test and 1 tooth with the control gel. Examinations were repeated 8 and 16 months post-operatively. RESULTS: After 16 months, the mean test PPD was 4.1 mm and the mean control PPD 4.2 mm. The mean gain of attachment was 2.7 mm for test and 2.9 mm for the control sites, and the radiographic measurements demonstrated a mean gain of 1 mm for both test and control sites. CONCLUSION: This series of cases demonstrated a statistically significant reduction of pocket depths and gain of attachment and bone after 8 and 16 months with no difference between the 2 preparations.

Risk of severe periodontal disease in a Swedish adult population. A longitudinal study.

The aim of this study was to identify risk factors for severe periodontal disease progression in a Swedish adult population between the years 1973 and 1988-91. In 1973, a random sample of 474 dentate adults living in Jönköping County was examined clinically and radiographically. A questionnaire on demographic and socio-economic status, general health, and dental care habits was also used. During the years 1988-1991, 361 of the individuals examined in 1973 were re-examined. A total of 506 (6%) teeth or in average 1.4 teeth per subject were lost between the 2 examinations. 4 subjects had become completely edentulous. The mean loss of teeth in the different age groups 20-60 years was 0.2, 0.9, 1.4, 2.3, and 2.6, respectively. The periodontal bone level decreased by age both in 1973 and in 1988 91. The mean annual progression rate was 0.06 mm for all 357 individuals and varied between 0.04 and 0.07 mm per subject in the different age groups. The presence of periodontal disease progression was defined as bone loss of >20% at a proximal site between the 2 examinations. The most prevalent tooth types with bone loss of >20% at proximal sites were the maxillary and mandibular 2nd molars and the 1st maxillary molar, representing a % of 18.0, 12.8, and 13.5, respectively. The degree of association between severe periodontal disease progression and explanatory variables was investigated using logistic regression models. The dependent variable was no progression of periodontal disease or severe periodontal disease progression, i.e., subjects with periodontal bone loss >20% at > or =6 sites. Age was found to be correlated with severe periodontal disease progression by an odds ratio of 1.05 (CI: 1.02-1.07). The frequency of females in the group with severe bone loss was 58% and higher than in the non-progressing group, 50%. Only 9% in the group with no bone loss smoked as compared to 38% in the group of individuals with severe periodontal bone loss. % supragingival plaque, gingival inflammation, and deepened periodontal pockets (> or =4 mm) at baseline were related to severe periodontal disease progression by odds ratios of 1.03 (CI: 1.02-1.05), 1.01 (1.00-1.03), and 1.03 (1.00-1.05), respectively. In the multivariate logistic regression model, age (odds ratio 1.13 (CI: 1.06-1.19)), smoking (odds ratio 20.25 (5.07-80.83)), and % pockets > or =4 mm (odds ratio 1.15 (1.04-1.27)) remained significantly associated with severe disease progression. Furthermore, female gender and differences in income level appeared in the multivariate analysis to be related with severe bone loss, with odds ratios of 3.19 (CI: 1.02-9.97) and 8.46 (CI: 1.97-36.37), respectively.

Tooth loss and periodontal bone level in individuals of Jönköping County. A comparison between two adult populations living in the city and in the surrounding area.

Cross-sectional and longitudinal studies were performed in the community (in this paper changed to city) of Jönköping, Sweden, over a period of 20 years to follow changes in oral health and oral health behaviour. To widen our knowledge about dental health and dental care among the adult population, we expanded the study in 1993 to cover the whole county. The specific aim of the present study was to describe tooth loss (excluding third molars) and periodontal bone level in adult residents of Jönköping County and to compare these two parameters in adults living in the city of Jönköping with the same in adults living in the rest of the county. Random samples of individuals 30, 40, 50, 60, and 70 years old were selected. A total of 484 persons from the city and 1219 subjects from the rest of the county were examined. A total of 32 (7%) and 27 (2%) persons were completely edentulous in the examined populations from the city and from the rest of the county, respectively. A majority belonged to the older age groups, 60 and 70 years, with 17% of the subjects in the city being edentulous compared with 13% in the rest of the county. The mean number of missing teeth in subjects in the city versus subjects in the rest of the county was 0.75/0.95, 1.37/1.60, 3.34/2.43, 6.34/7.40, and 9.95/10.26 in 30-, 40-, 50-, 60-, and 70-year-olds, respectively. Of all the different tooth types, the average number of molars per person decreased the most with increasing age from an average of 7.79/7.83 (city/county) to 3.06/3.09 (city/county) for 30- and 70-year-olds, respectively. The proportion of subjects without molars was higher in the older age groups in both the city and the rest of the county with 4.8/10.7% and 15.6/22.0% of the 60- and 70-year-olds, respectively, lacking molars. In both populations, the mean periodontal bone level decreased with age. It was concluded that no important differences in tooth loss and periodontal health could be seen between the two populations. When organising dental care, dental health administrators could apply the findings from the population in the city to the entire county.

Risk of severe periodontal disease in a Swedish adult population. A cross-sectional study.

In this study, potential risk factors for severe periodontal disease were identified in a cross-sectional sample from the county of Jonkoping, Sweden. 547 adults 20-70 years of age were categorised clinically and radiographically by level of periodontal disease experience. These levels were used to divide the sample into groups--individuals without any reduction in periodontal bone level (60%) and those with severe periodontal bone loss (13%)--which were then used in univariate and multivariate logistic regression analyses as dependent variable. Demographic, socio-economic, general health, smoking habits, clinical, and dental care variables were used in the different regression analyses. In the univariate model, age (20-70 years) was found to be correlated with more severe periodontal disease experience (odds ratio: 1.13; 95% CI: 1.10-1.17). The association with periodontal disease was more pronounced for the older age groups (50, 60, and 70 years). A negative financial situation was also related to severe periodontal bone loss when regressed univariately (odds ratio 2.20 [95%: 1.04-4.68]). Moderate-heavy smoking (> or =10 cigarettes/day) appeared to be associated with severe periodontal destruction with an odds ratio of 9.78 (95% CI: 3.62-36.42). Of the clinical variables in the univariate model, higher mean levels of supragingival dental plaque and the presence of subgingival calculus were related to more severe periodontal disease with odds ratios of 1.02 (95%: 1.01-1.03) and 2.96 (95%: 1.50-5.88), respectively. When the same variables were regressed multivariately, age (continuous) (odds ratio 1.17 [95% CI: 1.12-1.22]), moderate-heavy smoking (odds ratio 11.84 [95% CI: 4.19-33.50]), and higher mean levels of plaque (odds ratio 1.02 [95% CI: 1.00-1.03]) remained significant. Light smoking (1-9 cigarettes/day) was not significantly associated with severe periodontal disease in the 2 regression models. The present study demonstrated that smoking, greater age, and higher mean levels of plaque are potential risk factors for severe periodontal disease in this specific population.

Root conditioning using EDTA gel as an adjunct to surgical therapy for the treatment of intraosseous periodontal defects.

The aim of this clinical study was to compare the treatment outcome following root surface conditioning using an EDTA gel preparation in conjunction with surgical therapy with that following conventional flap surgery in periodontal intraosseous defects. 36 patients, each of them contributing one intraosseous defect > or =4 mm in depth participated. Defect sites had a probing pocket depth > or =5 mm and bled on probing following hygienic treatment phase. No furcation involvement or endodontic complications were present. In the EDTA group, 18 consecutive patients, defects were treated by root conditioning with EDTA gel for 3 minutes in combination with surgical therapy. In the control group, 18 patients, conventional flap surgery was performed without root conditioning. Chlorhexidine rinsings 0.2% were prescribed following surgery for 2-3 weeks with modified oral hygiene instruction. A strict recall program was implemented including professional prophylaxis and oral hygiene reinforcement every 4-6 weeks until 6-month re-evaluation. Baseline probing pocket depths and defect depths of 7.1+/-1.3 mm and 6.9+/-1.6 mm in the EDTA group and 7.6+/-1.9 mm and 6.6+/-1.7 mm, respectively, in the control group were measured. 6-month clinical results showed a significant probing attachment level gain of 1.8+/-1.5 mm and 1.0+/-1.7 mm in the EDTA and control groups respectively. A probing bone gain of 1.0+/-1.3 mm in the EDTA group was measured with a non-significant gain of 0.4+/-1.2 mm in the control group. Radiographic analysis confirmed these results. There were no statistically significant differences in treatment outcome between the group treated by root conditioning in combination with flap surgery and conventional flap surgery alone.

Oral hygiene and gingivitis in a Swedish adult population 1973, 1983 and 1993.

The periodontal condition of the inhabitants of Jönköping County, Sweden was followed for 20 years by means of 3 cross-sectional investigations performed in 1973, 1983, and 1993. The study comprised individuals in the age groups 20, 30, 40, 50, 60, and 70 years. The number of dentate individuals was 537 in 1973, 550 in 1983, and 552 in 1993. All individuals participating in the studies were examined clinically and radiographically. They also filled out a questionnaire about dental care habits, socio-economic status, and general health. A clear reduction in the plaque score was seen between 1973 and 1983 in all age groups. With one exception, no further significant change in plaque levels was found between 1983 and 1993: the increase in plaque among the 20-year-olds was significant. In 1993 the mean % of surfaces with plaque was between 30% and 40% in all age groups. Gingivitis values corresponded well with the values of dental plaque; the same pattern with a clear reduction in gingivitis score was seen in all age groups between 1973 and 1983, and an increase in the mean frequency of gingival inflammation between 1983 and 1993 was seen in the 20-year age group. 30% of the individuals in this age group had more than 50% gingivitis in 1993 compared with 9% of the individuals in 1983. The 20-year-olds were further analyzed in a linear regression model using gingivitis as a dependent variable against some socio-economic, general health, and dental care variables associated with poor oral hygiene and gingivitis. In 1993, the most important explanatory variable was gender: significantly more males than females had higher gingivitis scores. The second most important explanatory variable was toothbrushing habits. Together they explained 10.9% of the variance. The multivariate analysis did not reveal approximal cleaning habits to be significant, probably due to their strong connection to gender and toothbrushing habits. In the 1983 sample, no significant explanatory variables were found. It was concluded from this data that it is important not only to renew but also to direct preventive guidelines more towards young adults who have no previous extensive experience of oral disease so that they will not be excluded from dental care and their dental health thereby jeopardised. In addition to preventive programmes aimed at the population as a whole, individual programmes based on risk targeting are also necessary to reduce the number of people developing dental disease and to increase the quality of dental care.

Distribution of periodontal disease in a Swedish adult population 1973, 1983 and 1993.

The aim of this study was to compare changes in periodontal status in a Swedish population over a period of 20 years. Cross-sectional studies were carried out in Jönköping County in 1973, 1983, and 1993. Individuals were randomly selected from the following age groups: 20, 30, 40, 50, 60, and 70 years. A total of 600 individuals were examined in 1973, 597 in 1983, and 584 in 1993. The number of dentate individuals was 537 in 1973, 550 in 1983, and 552 in 1993. Based on clinical data and full mouth intra-oral radiographs, all individuals were classified into 5 groups according to the severity of the periodontal disease experience. Individuals were classified as having a healthy periodontium (group 1), gingivitis without signs of alveolar bone loss (group 2), moderate alveolar bone loss not exceeding 1/3 of the normal alveolar bone height (group 3), severe alveolar bone loss ranging between 1/3 and 2/3 of the normal alveolar bone height (group 4), or alveolar bone loss exceeding 2/3 of the normal bone height and angular bony defects and/or furcation defects (group 5). During these 20 years, the number of individuals in groups 1 and 2 increased from 49% in 1973 to 60% in 1993. In addition, there was a decrease in the number of individuals in group 3, the group with moderate periodontal bone loss. Groups 4 and 5 comprised 13% of the population and showed no change in general between 1983 and 1993. The individuals comprising these groups in 1993, however, had more teeth than those who comprised these groups in 1983; on the average, the individuals in disease group 4 had 4 more teeth and those in disease group 5, 2 more teeth per subject. In 1973, these 2 groups were considerably smaller, probably because of wider indications for tooth extractions and fewer possibilities for periodontal care which meant that many of these individuals had become edentulous and were not placed in a group. Individuals in groups 3, 4, and 5 were subdivided according to the number of surfaces (%) with gingivitis and periodontal pockets (> or =4 mm). In 1993, 20%, 42%. and 67% of the individuals in groups 3, 4, and 5 respectively were classified as diseased and in need of periodontal therapy with >20% bleeding sites and >10% sites with periodontal pockets > or =4 mm. In conclusion, an increase in the number of individuals with no marginal bone loss and a decrease in the number of individuals with moderate alveolar bone loss can be seen. The prevalence of individuals in the severe periodontal disease groups (4, 5) was unchanged during the last 10 years; however, the number of teeth per subject increased.

Periodontal regeneration in class III furcation defects of beagle dogs using guided tissue regenerative therapy with platelet-derived growth factor.

We developed an effective regenerative therapy, referred to as platelet-derived growth factor-BB (PDGF-BB)-modulated guided tissue regenerative (GTR) therapy (P-GTR), capable of achieving periodontal regeneration of horizontal (Class III) furcation defects in the beagle dog. To determine its efficacy, repair and regeneration of horizontal furcation defects by P-GTR therapy and GTR therapy were compared. Chronically inflamed horizontal furcation defects were created around the second (P2) and fourth mandibular premolars (P4). After demineralization of the root surfaces with citric acid, the surfaces of left P2 and P4 were treated with PDGF-BB (P-GTR therapy) and those of contralateral teeth were treated with vehicle only (GTR therapy). Periodontal membranes were placed and retained 0.5 mm above the cemento-enamel junction for both groups. The mucoperiosteal flap was sutured in a coronal position and plaque control was achieved by daily irrigation with 2% chlorhexidine gluconate. At 5, 8, and 11 weeks, two animals each were sacrificed by perfusion with 2.5% glutaraldehyde through the carotid arteries, and the lesions were sliced mesio-distally, demineralized, dehydrated, and embedded. Periodontal healing and regeneration after GTR and P-GTR therapy were compared by histomorphometric as well as morphological analysis. Morphometric analysis for each time period was performed on the pooled samples of P2 and P4. Five weeks after both therapies, the lesions were filled primarily by tissue-free area, epithelium, inflamed tissue, and a small amount of newly formed fibrous connective tissue. At 8 and 11 weeks after P-GTR therapy, there was a statistically greater amount of bone and periodontal ligament formed in the lesions. The newly formed bone filled 80% of the lesion at 8 weeks and 87% at 11 weeks with P-GTR therapy, compared to 14% of the lesion at 8 weeks and 60% at 11 weeks with GTR therapy. Also, with P-GTR therapy there was less epithelium and tissue-free area, less inflamed tissue, and less connective tissue. Morphological analysis indicated that the defects around P2 revealed faster periodontal repair and regeneration than those around P4. While the lesions around P2 were effectively regenerated by 11 weeks even after GTR therapy, those around P4 failed to regenerate. On the other hand, P-GTR therapy further promoted periodontal repair and regeneration so that at 8 weeks the lesions around P2 and P4 demonstrated complete and nearly complete regeneration, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Assessment of risk for periodontal disease. I. Risk indicators for attachment loss.

Specific risk indicators associated with either susceptibility or resistance to severe forms of periodontal disease were evaluated in a cross-section of 1,426 subjects, 25 to 74 years of age, mostly metropolitan dwellers, residing in Erie County, New York, and surrounding areas. The study sample exhibited a wide range of periodontal disease experience defined by different levels of attachment loss. Therefore, it was possible to accurately assess associations between the extent of periodontal disease and patient characteristics including age, smoking, systemic diseases, exposure to occupational hazards, and subgingival microbial flora. Age was the factor most strongly associated with attachment loss, with odds ratios for subjects 35 to 44 years old ranging from 1.72 (95% CI: 1.18 to 2.49) to 9.01 (5.86 to 13.89) for subjects 65 to 74 years old. Diabetes mellitus was the only systemic disease positively associated with attachment loss with an odds ratio of 2.32 (95% CI: 1.17-4.60). Smoking had relative risks ranging from 2.05 (95% CI: 1.47-2.87) for light smokers increasing to 4.75 (95% CI: 3.28-6.91) for heavy smokers. The presence of two bacteria, Porphyromonas gingivalis and Bacteroides forsythus, in the subgingival flora represented risks of 1.59 (95% CI: 1.11-2.25) and 2.45 (95% CI: 1.87-3.24), respectively. Our results show that age, smoking, diabetes mellitus, and the presence of subgingival P. gingivalis and B. forsythus are risk indicators for attachment loss. These associations remain valid after controlling for gender, socioeconomic status, income, education, and oral hygiene status expressed in terms of supragingival plaque accumulation and subgingival calculus. Longitudinal, intervention, and etiology-focused studies will establish whether these indicators are true risk factors.

Periodontal status of women taking postmenopausal estrogen supplementation.

The association between supplementary estrogen intake and periodontal and gingival status in a total of 228 women 50 to 64 years of age was examined. Clinical parameters including visible supragingival plaque, subgingival calculus, probing pocket depth, clinical attachment level, alveolar bone height measurements, and number of remaining teeth were measured. Gingival status was recorded as gingival bleeding after gentle manipulation. Selected periopathogens, socio-economic, demographic, smoking habits, and health care variables were assessed. Gingival bleeding was significantly lower in the estrogen supplement group (n = 57) compared to the control group (n = 171) (P = 0.009); the estrogen group also exhibited significantly lower visible plaque levels (P = 0.030) and fewer Capnocytophaga-ssp. (P = 0.032). Dental care was more frequent (P < 0.001), and education levels were higher (P = 0.022) in the estrogen group. To investigate whether differences among the above parameters contributed to the difference in gingival bleeding, an age-adjusted analysis of covariance (ANCOVA) was used. The final ANCOVA indicated non-significant relationships for all parameters examined except estrogen intake (P = 0.044). Women taking estrogen exhibited lower gingival bleeding than the control group after correcting for these factors. The results indicate that estrogen supplementation is associated with less gingival bleeding in women aged 50 to 64, as compared to an age-matched control group.

Guided tissue regeneration and anti-infective therapy in the treatment of class II furcation defects.

The purpose of the present study was to evaluate the effect of anti-infective therapy on the success of periodontal regeneration in mandibular Class II furcation defects. Eighteen patients with mandibular bilateral Class II furcation defects were enrolled. Following an initial hygienic phase, guided tissue regeneration (GTR) was performed using an expanded polytetrafluoroethylene (e-PTFE) membrane barrier. The area was surgically exposed, thoroughly root planed, and irrigated with either tetracycline (100 mg/ml) or 0.9% saline. Post-operative care included systemic tetracycline (250 mg q.i.d.) and chlorhexidine 0.12% mouthwash twice daily. Patients were maintained on a prophylaxis schedule of every 2 weeks for the first 3 months, and monthly thereafter. Clinical parameters of probing depth (PD), probing attachment level - vertical (PAL-v), probing attachment level - horizontal (PAL-h), and target periodontal pathogens were monitored at baseline and quarterly for one year. An overall improvement in all clinical parameters was observed in both groups: probing reduction (3.1 mm), PAL-h gain (2.3 mm), and PAL-v gain (1.2 mm) were all statistically significant compared to baseline measurements. Vertical measurements were performed parallel to the long axis of the tooth with no attempt to angulate the probe into the furcation. There was no significant difference in sites receiving tetracycline. A strong positive correlation was noted between initial PD and pocket reduction (r = 0.77, P < 0.0001) and between initial PD and PAL-h gain (r = 0.54) and PAL-v gain (r = 0.45) suggesting that initial probing depth might be used to assess the regenerative potential of a given site.(ABSTRACT TRUNCATED AT 250 WORDS)

Topical application of tetracycline-HCl in human periodontitis.

Previous in vitro studies have suggested that tetracycline-HCl (TTC-HCl) is adsorbed and actively released from root dentin. The aim of the current study was to evaluate the binding to and release of TTC-HCl from human root dentin surfaces in vivo, and to evaluate the clinical utility of TTC-HCl irrigation as an adjunct to scaling and root planing. Experiment I utilized two contralateral mandibular single-rooted teeth which were examined in four adults with severe generalized periodontitis. One tooth in each patient was carefully scaled and root planed, under local anesthesia, and the other used as an unscaled control. Each subgingival root surface was irrigated for 5 min with an aqueous TTC-HCl solution at a concentration of 100 mg/ml. Gingival crevicular fluid samples were collected on paper strips for the next three weeks. The TTC-HCl concentrations in each sample were determined by the inhibition zone of B. cereus cultured on agar plates. The TTC-HCl concentrations in gingival crevicular fluid collected 15 min after irrigation were 3100 +/- 670 micrograms/ml from the scaled lesions and 4700 +/- 1300 micrograms/ml from the unscaled root surfaces. The antibiotic concentrations decreased logarithmically over the next 7 days; 1500 +/- 270 micrograms/ml and 1100 +/- 330 micrograms/ml at 2 h, 880 +/- 350 micrograms/ml and 1300 +/- 360 micrograms/ml at 6 h and 19 +/- 5 micrograms/ml and 31 +/- 26 micrograms/ml at 1 week for scaled and unscaled root surfaces, respectively. Results for week two and three indicated an average of over 8 micrograms/ml.(ABSTRACT TRUNCATED AT 250 WORDS)