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.

The human periodontal ligament cell: a fibroblast-like cell acting as an immune cell.

BACKGROUND: Periodontal ligament cells are fibroblast-like cells characterized by collagen production but also possessing some osteoblastic features. In the light of numerous studies presented during recent times, which show that human periodontal ligament cells also produce cytokines and chemokines in response to inflammation promoters, it is reasonable to suggest that periodontal ligament cells play a role as promoters of periodontal inflammation through these mechanisms. MATERIAL AND METHODS: The periodontal ligament, which harbours the periodontal ligament cells, is a part of the attachment apparatus comprised of periodontal ligament cells, extracellular matrix and fibres, attaching the root cement to the alveolar bone. Periodontal ligament cells are in close proximity to bacteria within the plaque and the pocket, and thus these cells are readily accessible to bacterial endotoxins and other promoters of inflammation. RESULTS: Cytokines and chemokines, released by periodontal ligament cells upon stimulation with inflammation promoters, reach the blood vessels easily thanks to rich vascularization of the periodontium stimulating recruitment of white blood cells to the site of inflammation. In addition to classical inflammatory cells, such as leucocytes, macrophages and mast cells, the periodontal ligament cells also contribute to periodontal inflammation via their production and release of cytokines and chemokines. CONCLUSION: Therefore, pharmacological treatment of periodontitis should aim to reduce the release of proinflammatory agents not only from classical inflammatory cells but also from periodontal ligament cells.

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.

LPS induces GROalpha chemokine production via NF-kappaB in oral fibroblasts.

OBJECTIVE AND DESIGN: Chemotaxis of neutrophils from blood to the inflammation process plays an important role in development of periodontal inflammation. The novel chemokine GROalpha, also named CXCL1, is a strong chemoattractant for neutrophils. Data on production and regulation of GROalpha by oral fibroblasts have not previously been presented. MATERIALS AND METHODS: GROalpha mRNA and protein levels were determined in human periodontal ligament cells and mouse gingival fibroblasts by quantitative real-time PCR and ELISA. RESULTS: We disclose that both human periodontal ligament cells and mouse gingival fibroblasts produce GROalpha in response to LPS stimulation. Stimulation with LPS for 24 h increased both mRNA for GROalpha and GROalpha protein. The steroid hormone estrogen had no effect on LPS-induced GROalpha mRNA expression. Treatment with the glucocorticoid dexamethasone attenuated LPS-induced GROalpha production, and the NF-kappaB blocker MG 132 fully prevented LPS-induced GROalpha. CONCLUSIONS: Oral fibroblasts respond to LPS stimulation by increasing GROalpha production via the transcription factor NF-kappaB, suggesting that this mechanism may be involved in development of periodontal inflammation.

Type 2 diabetes and risk for periodontal disease: a role for dental health awareness.

BACKGROUND: Several studies have found correlations between diabetes and an increased prevalence of periodontitis. OBJECTIVE: To analyse, in a group of subjects with type 2 diabetes (T2D), (i) the association between medical characteristics and severe periodontal disease and (ii) dental care habits and knowledge of oral health. METHODS: One hundred and ninety-one subjects with T2D were examined. Based on assessment of marginal bone height in panoramic radiographs, two periodontal subgroups were identified: one periodontally diseased (PD+) and one periodontally healthy (PD-) group. All subjects completed a questionnaire about their medical and oral health. RESULTS: Twenty per cent of the subjects were classified as PD+. This was verified by clinical parameters. PD+ individuals had higher haemoglobin A1c (HbA1c) levels (p=0.033) and higher prevalences of cardiovascular complications (p=0.012). They were also less likely to be of Scandinavian origin (p=0.028) and more likely to smoke (p<0.001) than the PD- group. The PD+ group rated their oral health as poor (p<0.0001) and believed that T2D had an influence on their oral status (p<0.0001). CONCLUSION: The best predictor for severe periodontal disease in subjects with T2D is smoking followed by HbA1c levels. T2D subjects should be informed about the increased risk for periodontal disease when suffering from T2D.

Differential effects of estrogen on DNA synthesis in human periodontal ligament and breast cancer cells.

BACKGROUND: It is important to clarify the biological function of the female sex hormones estrogen and progesterone in periodontal ligament cells, as these hormones may affect periodontal health. We have previously shown that human periodontal ligament cells express estrogen receptor beta (ERbeta) but not ERalpha, whereas human breast cancer cells (MCF7) express both ERalpha and ERbeta. Data on progesterone receptor (PgR) expression in human periodontal ligament cells have not been reported. OBJECTIVES: Determine PgR expression in human periodontal ligament and MCF7 cells and to investigate how estrogen affects DNA and collagen synthesis in these two cell types showing different pattern of expression for ERalpha and beta. METHODS: Periodontal ligament cells were obtained from the periodontal ligament of premolars extracted for orthodontic reasons and MCF7 cells from the American Type Culture Collection (ATCC). PgR expression was determined by immunocytochemistry. DNA and collagen synthesis was determined by [(3)H]thymidine and L-[(3)H]proline incorporation, respectively. RESULTS: PgR immunoreactivity was observed in nuclei of MCF7 but not periodontal ligament cells. Treatment with estrogen (17beta-estradiol, E(2)) at physiological concentrations for 24 h stimulated DNA synthesis by more than two times in MCF7 cells, whereas there was no effect on periodontal ligament cell DNA synthesis. The ER blocker ICI 182780 fully reversed the stimulatory effect of E(2). Not only short-term (24 h) but also long-term (5 days) treatment with E(2) lacked effect on DNA synthesis in periodontal ligament cells. Neither periodontal ligament cell viability nor collagen synthesis was affected by E(2) treatment. Identical results were observed in periodontal ligament cells from male and female subjects. CONCLUSIONS: Human MCF7 but not periodontal ligament cells express PgR, suggesting that progesterone via PgR affects MCF7 but not periodontal ligament cells. Further, estrogen stimulates breast cancer MCF7 cell proliferation, whereas it has no effect on proliferation of periodontal ligament cells, probably reflecting cell type specific ER expression pattern in these two cell types.

Immunocytochemical demonstration of estrogen receptor beta in human periodontal ligament cells.

Two transcription associated estrogen receptor (ER) subtypes have been identified and named ERalpha and ERbeta. In the present study we investigate the expression of these ER subtypes in cultured human periodontal ligament (PDL) cells by immunocytochemistry. ERbeta immunoreactivity was observed in the nuclei of about 40% of the PDL cells, while no ERalpha immunoreactivity was detected. In human breast cancer MCF-7 cells, serving as positive controls, both ERalpha and ERbeta immunoreactivities were demonstrated. No immunoreactivity was observed after omission of the primary antibodies. This study suggests that estrogen acts on gene transcription preferentially via ERbeta in human PDL cells.

Clinical outcome observed in subjects with recurrent periodontal disease following local treatment with 25% metronidazole gel.

BACKGROUND: The aim of this study was to evaluate the clinical outcome in patients with recurrent periodontal disease following treatment with 25% metronidazole gel. METHODS: Twenty subjects in a maintenance care program but with recurrent periodontal disease participated. Three months after scaling and root planing, a total of 40 sites, 2 in each patient, with probing depth > or = 5 mm were selected. One site randomly selected was treated with metronidazole gel (test) and the other site with a placebo gel (control). Baseline and follow-up measurements included plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), and clinical attachment level (CAL). RESULTS: There were no statistically significant differences in PI, GI, BOP, PD, or CAL between test and control sites. CONCLUSION: This study showed that local treatment with 25% metronidazole gel did not seem to influence the clinical healing in this group of subjects with recurrent periodontal disease.

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.

Guided tissue regeneration in the treatment of human infrabony defects. Clinical, radiographical and microbiological results: a pilot study.

The aim of the study was to evaluate the clinical, radiographical and microbiological outcome after using guided tissue regeneration (GTR) with a bioabsorbable membrane, Resolut. Subjects with bilateral infrabony defects at single rooted teeth were selected. A total of 22 teeth, 2 in each 1 of 7 patients and 4 in 2 patients, with probing pocket depth > or =5 mm, 3 months after scaling, participated. At baseline, assessments of plaque and gingival indices, bleeding on probing, probing pocket depth and probing attachment level were recorded and reproducible radiographs for computer-based bone level measurements were taken. Bacterial samples were collected to investigate the presence of periodontitis-associated bacteria, e.g., Porphyromonas/Prevotella- and Fusobactrium-like micro-organisms. One tooth was randomly treated with GTR and the contralateral with an open debridement procedure as a control. Clinical, radiographical and microbiological examinations were repeated 6 and 12 months postoperatively. Both procedures demonstrated a statistically significant improvement of gingival conditions, reduction of pocket depths and gain of attachment. When evaluating the differences between test and control teeth, none of the clinical parameters yielded statistical difference. Computer-based bone-level measurements showed only small differences in the majority of both test and control sites. The differences were not significant. Periodontitis-associated bacteria were present at baseline, but the appearance was not related to any specific site or patient and did not demonstrate any unwanted change in the 6- and 12-month samples. The findings suggest that the clinical, radiographical and microbiological improvements were not significantly enhanced with the GTR therapy.

Guided tissue regeneration for the treatment of intraosseous defects using a biabsorbable membrane. A controlled clinical study.

The aim of this controlled, clinical study was to evaluate guided tissue regeneration using a bioabsorbable membrane in periodontal intraosseous defects. Forty patients, each contributing one defect > or =4 mm in depth participated. The control group (18 individuals) received conventional flap therapy, while the test group (22 individuals) was treated using the bioabsorbable membrane, Guidor. Clinical assessments were made by one examiner, blinded with respect to treatment group, at baseline, 6 and 12 months following surgery. Baseline probing pocket depths of 7.7+/-1.4 mm in the membrane group and 7.6+/-1.9 mm in the control group were measured. Twelve month results showed a significant clinical attachment level gain in both control (1.1+/-1.8 mm), and membrane group (1.3+/-2.1 mm). Probing pocket depth reduction of 2.6+/-1.9 mm and 2.7+/-1.9 mm was observed in the respective groups. Bone sounding showed a non-significant gain of 0.4+/-1.8 mm and 0.6+/-1.4 mm at membrane and control sites, respectively. Radiographic evaluation confirmed these results. There were no significant differences found between treatment groups for any of the tested variables. Smoking had a negative effect on healing in both groups. In conclusion, clinical and radiographic results indicate that guided tissue regeneration using a bioabsorbable membrane at intraosseous defects did not predictably achieve greater clinical attachment level gain nor bone gain when compared to conventional flap therapy.

Periodontal probe precision using 4 different periodontal probes.

The aim of this study was to compare the relative intra- and inter-examiner reproducibility of 4 different periodontal probes. (1) The Hu- Friedy LL 20 Probe, a manual probe. (2) The Vivacare TPS Probe, a plastic manual probe with a standardised pressure of 0.20 N. (3) The Vine Valley Probe, an electronic probe using a standardised pressure of 0.25 N. 4. The Peri Probe Comp, a computerised electronic probe with a controlled pressure of 0.45 N in 2 mm pockets to 0.25 N in 13 mm pockets. Duplicate probing measurements were taken by 2 examiners in 10 patients on 3 index teeth, 1 molar, 1 premolar and 1 incisor at 6 sites per tooth. Teeth were selected to incorporate both shallow (< 5 mm) and deeper (> or = 5 mm) periodontal sites. The order of probes and examiners were changed in a systematic manner and measurements were repeated 1 week later to avoid bias due to examiner memory. Results show that the manual probe had the lowest degree of variation, with a correlation coefficient of 0.83. The manual and Peri Probe Comp frequently recorded deeper probing pocket depths compared to the TPS and Vine Valley probes. The results may have been influenced by the lack of familiarity with the automated probes.

Treatment of furcation defects. Guided tissue regeneration versus coronally positioned flap in mandibular molars; a pilot study.

The present study was designed to compare the healing results after treatment of buccal class II furcation defects in mandibular molars utilizing guided tissue regeneration (GTR) technique or coronally positioned flap (CPF) technique. The patient sample consisted of 8 subjects with 18 bilateral furcation defects in mandibular molars. At baseline, 6 and 12 months postoperatively assessments of plaque index, gingival index, probing pocket depths, probing attachment level and bleeding on probing were recorded. Radiographic assessment was performed using conventional radiographs and subtraction images at baseline and 12 months postoperatively. The furcation defects were randomly assigned in each patient to either the GTR or the CPF technique. 12 months postoperatively, there was a statistically significant reduction in probing pocket depths in the GTR treated teeth and a tendency to gain of probing attachment levels 6 months postoperatively. The CPF group showed a statistically significant reduction of probing pocket depths at 6 months and a tendency to reduction after 12 months. The radiological assessment demonstrated gain of interradicular bone tissue in 2 furcation defects of the GTR group. Gain of bone tissue could not be demonstrated in the CPF group. No statistically significant differences were observed between the 2 treatment modalities.

Clinical and microbiological effects of subgingival application of a chlorhexidine gel in chronic periodontitis. A pilot study.

Clinical and microbiological effects of subgingival application of a 1% chlorhexidine gel were studied. Eleven patients with chronic periodontitis participated in the study. In each patient two pairs of single rooted teeth with at least 20% attachment loss and probing depth > 4 mm were selected. Contralateral sites were randomly allocated to test and control groups receiving chlorhexidine or placebo gel respectively. The gels were applied once daily for two consecutive days. The clinical parameters comprised plaque index, gingival index, probing pocket depth and bleeding on probing. The composition of the subgingival microbiota was estimated with use of dark field microscopy. Baseline measurements were taken two weeks prior to chlorhexidine application. Microbiological and clinical parameters were further monitored 2, 7, 14 and 28 days after the last gel application. Chlorhexidine gel application did not significantly change the composition of the microflora compared to placebo application. There were no major differences in plaque and gingival indices. Effects on probing pocket depth of the chlorhexidine gel application may have been disguised by an influence from the diameter of the needle with which the application was performed. Needles with a diameter of 25G resulted in increases in probing pocket depth which indicates a possible mechanical trauma. This effect was not observed when needles with a diameter of 23G were used.

Guided tissue regeneration in the treatment of infrabony defects on maxillary premolars. A pilot study.

The present study evaluated clinically and radiographically the short-term results of the healing of infrabony defects at maxillary premolars treated according to guided tissue regeneration (GTR). 9 patients with bilateral presence of infrabony defects with or without furcation involvements at maxillary premolars were selected. At baseline assessments of plaque and gingival indices, bleeding, probing pocket depth and attachment level, and furcation measurements were recorded. Conventional radiographs were obtained in a way that assured a reproducible projection geometry. One premolar was randomly treated with GTR and the contralateral with open debridement. Clinical and radiographic examinations were performed again 6 months postoperatively. The bone tissue changes were assessed by means of conventional radiographs and subtraction images. Sites treated by both procedures demonstrated an improvement of gingival conditions and a reduction of pocket depths. A statistically significant attachment gain was obtained for the test (mean 1.2 mm), but not for the control sites (mean 0.6 mm). The differences, though, were not significant between the test and control sites. Limited improvement in furcation closure was recorded. The radiographic examination demonstrated loss of bone tissue in four sites treated with GTR. The findings suggest that the regeneration of the periodontal soft and bone tissues was not significantly enhanced with the GTR therapy.

Gingivectomy versus flap surgery: the effect of the treatment of infrabony defects. A clinical and radiographic study.

The aim of this paper was to compare the short-term results of gingivectomy (GV) and modified Widman flap (MWF) surgery in the treatment of infrabony defects. 14 patients with 68 bilateral infrabony defects were selected. At baseline, and 3 and 6 months postoperatively, assessments of oral hygiene, gingival conditions, bleeding on probing, probing pocket depth and attachment level, were recorded. Conventional radiograps were obtained in a way that assured a reproducible projection geometry. In a split-mouth design, one jaw quadrant was randomly treated with GV, while the contralateral with a MWF. The changes of the bone tissue were assessed by means of conventional and subtraction images by 2 observers. The interobserver agreement of the conventional and subtraction technique was studied. The majority of the sites demonstrated a significant improvement in gingival conditions and a reduction in bleeding. For both treatments, probing depths were reduced by an average of 3 mm, while a mean of 1.22-1.35 mm of probing attachment gain was obtained. The GV resulted in slightly more gingival recession (1.90 mm) than the MWF (1.60 mm). The radiographic examination demonstrated gain of bone in 7 defects treated with GV and in 9 defects treated with MWF. This study demonstrated that pockets associated with infrabony defects can be successfully treated by both treatment modalities. Furthermore, bone gain can occur after treatment but not in a predictable manner.

Dental health knowledge in a group of Latin American refugees in Sweden.

Sixty-nine Latin American refugees with a mean age of 31 years participated in this study. The knowledge about dental health before and after reading a self-instructional manual in Spanish was tested by questionnaires. The test persons were also interviewed about their dietary habits. The results showed an improvement of 30% of right answers after reading the manual and that a frequent sugar consumption was common. This indicates that a self-instructional manual can be of value in oral health prevention in a similar group of non-resident immigrants.

Crevicular and salivary fibronectin before and after gingivitis treatment.

The aims of this study were to assess crevicular fibronectin concentrations before and after conventional gingivitis treatment and to determine whether fibronectin concentration in whole saliva would be affected concomitantly. 10 subjects with generalized gingivitis were selected. Examinations were made before and after treatment and included measurements of clinical parameters as well as collection of samples of unstimulated saliva, stimulated saliva and crevicular material. The concentration of fibronectin was studied by an ELISA assay. Fibronectin was found in gingival crevices and in unstimulated as well as paraffin-stimulated whole saliva in pre- and post-treatment samples. There were no statistically significant differences between pre- and post-treatment concentrations of fibronectin, whether expressed as micrograms fibronectin/micrograms protein or as micrograms fibronectin/ml saliva.