Effects of prostaglandin E2 and D2 on cell proliferation and osteogenic capacity of human mesenchymal stem cells.

The manifestation of periodontitis-related inflammatory reaction is inevitably bound to the production of prostaglandins E2 and D2 which have been suggested to mediate osteoclastic and osteogenic effects within the affected tissue. We demonstrated the presence of PGE2 and PGD2 receptors on hMSCs on RNA level and with immunofluorescence. For each Prostaglandin, three concentrations were studied: 0.1; 0.5 or 1.0 µg/ml. A lower expression of EP1 and EP4 (PGE2 receptors 1 and 4) after stimulation with PGE2 was shown, thus a tendency to compromise osteogenic differentiation and metabolism. PGE2 induced a higher growth-rate during the first week, while a continuous inflammatory challenge determined a decrease of the proliferation of hMSCs. PGD2 inhibited cell growth irrespective of the duration of the stimulation. PGE2 and PGD2 have also negative effects on calcium deposition osteogenic, thus on differentiation of hMSCs. PGE2 and PGD2 seem to induce bone resorption also having indirectly a negative impact on the osteogenic differentiation of hMSCs. Thus, inhibitors of PGE2 and PGD2 can be used as adjunct to mechanical periodontal treatment.

Variants of the human NR1I2 (PXR) locus in chronic periodontitis.

BACKGROUND AND OBJECTIVE: Recent studies on genetic variants of the pregnane X receptor (PXR) revealed associations with the mucosal immune response. This study aimed to investigate the potential association of functional polymorphisms of the NR1I2 (PXR)-encoding gene (rs12721602, rs3814055, rs1523128, rs1523127, rs45610735, rs6785049, rs2276707 and rs3814057) with chronic periodontitis. MATERIAL AND METHODS: At total of 402 periodontitis patients and 793 healthy individuals were genotyped using PCR and melting-curve analysis. RESULTS: Frequency distribution of genotypes for the eight single nucleotide polymorphisms showed no significant difference between patients with periodontitis and controls. Among the eight tested polymorphisms, two blocks were defined showing complete or almost complete linkage disequilibrium (linkage disequilibrium block 1: rs3814055 and rs1523127; and linkage disequilibrium block 2: rs6785049, rs2276707 and rs3814057). For one haplotype (GTGAG) composed of rs12721602, rs3814055, rs1523128, rs12721607 and rs6785049, a significant association with periodontitis was found [p-value after permutation with 100,000 iterations (p(permut.)) = 0.011, odds ratio = 0.46, 95% confidence interval: 0.25-0.84) following adjustment for age, gender and smoking. CONCLUSION: A rare haplotype of the NR1I2 (PXR) locus was associated with the individual susceptibility for chronic periodontitis in a German cohort. As a result of the borderline significance and the small effect size the present results need further confirmation.

Impact of MICA-TM, MICB-C1_2_A and C1_4_1 microsatellite polymorphisms on the susceptibility to chronic periodontitis in Germany.

The major histocompatibility complex class I chain-related gene A (MICA)-TM exon 5 trinucleotide polymorphism, the MICB-C1_2_A intron 1 dinucleotide polymorphism and the tetranucleotide polymorphism C1_4_1 located in the major histocompatibility complex class I region on chromosome 6 were shown to influence various chronic inflammatory conditions. We investigated the association of these microsatellite polymorphisms with chronic periodontitis, a highly prevalent oral inflammatory disease in 389 periodontitis patients and 771 healthy controls with South German genetic background. Genotyping of the MICA-TM, MICB-C1_2_A and C1_4_1 microsatellite polymorphisms was performed by PCR amplification and fragment analysis. Global frequency distribution of MICB-C1_2_A (P = 0.006) and C1_4_1 (P = 0.028) alleles was significantly different between both study groups. Allele-specific analysis revealed that the MICA-TM allele A5 was more prevalent among male periodontitis patients [P = 0.0001; odds ratio (OR) 2.17, 95% confidence interval (CI) 1.55-3.03]. In C1_4_1 allele, three was significantly higher in healthy controls (P = 0.006; OR 0.74, 95% CI 0.60-0.91). Two haplotypes (MICA:A5-C1_4_1:5; P = 0.002; OR 2.63, 95% CI 1.46-4.74 and MICB:CA16-C1_4_1:3; P = 0.014; OR 0.68, 95% CI 0.50-0.92) showed significant differences between periodontitis patients and controls. The MICA-TM, MICB-C1_2_A and C1_4_1 microsatellite polymorphism seem to influence the individual susceptibility to chronic periodontitis in patients with German genetic background.

A 3' UTR transition within DEFB1 is associated with chronic and aggressive periodontitis.

Periodontal diseases are complex inflammatory diseases and affect up to 20% of the worldwide population. An unbalanced reaction of the immune system toward microbial pathogens is considered as the key factor in the development of periodontitis. Defensins have a strong antimicrobial function and are important contributors of the immune system toward maintaining health. Here, we present the first systematic association study of DEFB1. Using a haplotype-tagging single nucleotide polymorphism (SNP) approach, including described promoter SNPs of DEFB1, we investigated the associations of the selected variants in a large population (N=1337 cases and 2887 ethnically matched controls). The 3' untranslated region SNP, rs1047031, showed the most significant association signal for homozygous carriers of the rare A allele (P=0.002) with an increased genetic risk of 1.3 (95% confidence interval: 1.11-1.57). The association was consistent with the specific periodontitis forms: chronic periodontitis (odds ratio=2.2 (95% confidence interval: 1.16-4.35), P=0.02), and aggressive periodontitis (odds ratio=1.3 (95% confidence interval 1.04-1.68), P=0.02). Sequencing of regulatory and exonic regions of DEFB1 identified no other associated variant, pointing toward rs1047031 as likely being the causative variant. Prediction of microRNA targets identified a potential microRNA-binding site at the position of rs1047031.

MICA*055: a new allele with eight GCT repeats in the exon 5 microsatellite.

The new allele MICA*055 contains eight GCT repeats within the exon 5 MICA-TM microsatellite polymorphism.

Increased plasma concentration of surfactant protein D in chronic periodontitis independent of SFTPD genotype: potential role as a biomarker.

Surfactant protein (SP) D belongs to the family of collectins, which are humoral molecules of the innate immune system. Collectins belong to pattern recognition receptors and are present in plasma and on mucosal surfaces and recognize several microbial components, the pathogen-associated molecular patterns (PAMPs). While SP-A is primarily expressed in the lung, expression of SP-D is more widely detected including different mucosal surfaces and in serum. Therefore, SP-D is considered a functional candidate in chronic periodontitis. The present study sought to investigate whether plasma concentration of SP-D is altered in chronic periodontitis and whether polymorphisms within the SFTPD gene (Met11Thr, Ala160Thr and Ser270Thr) are associated with chronic periodontitis. The study population comprised 105 patients with chronic periodontitis and 122 healthy, unrelated control individuals. SP-D Plasma concentrations were determined using enzyme-linked immunosorbent assay test. Genotyping of SFTPD polymorphisms was performed by polymerase chain reaction and restriction fragment length polymorphism analysis. Plasma concentrations were significantly increased in patients with chronic periodontitis compared with the controls. The median plasma concentrations were 81.6 ng/ml in the patients and 52.6 ng/ml in the controls (P = 0.00051). In contrast, the three SFTPD polymorphisms displayed no significant association with chronic periodontitis; thus, the increased plasma concentrations were independent on the genotype. The study showed significantly increased SP-D plasma concentrations in patients with chronic periodontitis compared with healthy controls. Thus, SP-D can potentially be used as a biomarker for chronic periodontitis. As no significant associations of SFTPD gene polymorphisms could be detected, other mechanisms influencing SP-D serum/plasma expression might exist.

A645G (Lys216Glu) polymorphism of the bactericidal/permeability-increasing protein gene in periodontal disease.

Bactericidal/permeability-increasing protein (BPI) is a member of the pattern recognition receptors of the innate immune system and recognizes lipopolysaccharides (LPS), a bacterial component belonging to the pathogen-associated molecular patterns (PAMPs). BPI mediates the neutralization of LPS and increases the phagocytosis and cytotoxicity against bacteria. Recently, the functionally effective polymorphism A645G resulting in the amino acid alteration Lys216Glu has been described. The aim of the study was to investigate the association of the A645G polymorphism with chronic periodontal disease. The study population comprised 123 patients with periodontal disease (36 with mild, 52 with moderate and 35 with severe periodontitis) and 122 healthy, unrelated control individuals. Genotyping of the BPI gene polymorphism A645G (Lys216Glu) was performed by polymerase chain reaction and restriction fragment length polymorphism analysis. Statistical analysis was carried out employing the chi(2) test with Yates correction. Genotype and allele frequencies of the polymorphism tested herein showed no significant differences between periodontal disease as compared to the control group. The frequencies of the G allele were 52.4% in patients with periodontal disease and 49.2% in the control individuals (P = 0.528). Moreover, no significant associations could be detected after stratification for disease severity and according to gender. The present study does not give evidence for the contribution of the BPI gene to the genetic background of chronic periodontal disease.

The leukocyte count predicts the efficacy of treatment with azathioprine in inflammatory bowel disease.

INTRODUCTION: Azathioprine has variable efficacy in inflammatory bowel disease. Previous studies suggested that either neutropenia, an increase in the mean corpuscular volume, the assessment of thiopurine methyl-transferase activity or erythrocyte 6-thioguanine values might predict the treatment response. However, due to the conflicting results of the preceding studies there are yet no established laboratory values which allow an estimation of the clinical response. PATIENTS AND METHODS: 45 patients with Crohn's disease and 39 patients with ulcerative colitis were enrolled in this retrospective evaluation. After a minimum of six months therapy with azathioprine patients in remission were compared with those who did not achieve a stable remission with respect to the number of leucocytes, lymphocytes, neutrophil granulocytes and the mean corpuscular volume. RESULTS: Patients who went into remission during treatment with azathioprine displayed significantly lower leukocyte counts if compared to patients who were not in remission (p = 0.004 in Crohn's disease and 0.003 in ulcerative colitis). A similar tendency was also observed with respect to the granulocyte count (p = 0.007 in Crohn's disease and 0.004 in ulcerative colitis). The mean corpuscular volume did not correlate with the response to purine analogues. DISCUSSION: The absolute leukocyte count and the percentage of granulocytes seem to predict the response to purine analogues in inflammatory bowel disease and possibly offers a feasible and cost effective diagnostic tool for the assessment of therapeutic efficacy. Subsequent preferably prospective studies should aim to define the optimal cut-off value for the leukocyte count.

Effectiveness of 4 pulpotomy techniques--randomized controlled trial.

Pulpotomy is the accepted therapy for the management of cariously exposed pulps in symptom-free primary molars; however, evidence is lacking about the most appropriate technique. The aim of this study was to compare the relative effectiveness of the Er:YAG laser, calcium hydroxide, and ferric sulfate techniques with that of dilute formocresol in retaining such molars symptom-free. Two hundred primary molars in 107 healthy children were included and randomly allocated to one of the techniques. The treated teeth were blindly re-evaluated after 6, 12, 18, and 24 months. Descriptive data analysis and logistic regression analysis, accounting for each patient's effect by a generalized estimating equation (GEE), were used. After 24 months, the following total and clinical success rates were determined (%): formocresol 85 (96), laser 78 (93), calcium hydroxide 53 (87), and ferric sulfate 86 (100). Only calcium hydroxide performed significantly worse than formocresol (p = 0.001, odds ratio = 5.6, 95% confidence interval 2.0-15.5). In conclusion, calcium hydroxide is less appropriate for pulpotomies than is formocresol.

Serum antibodies in first-degree relatives of patients with IBD: a marker of disease susceptibility? A follow-up pilot-study after 7 years.

INTRODUCTION: Various disease-specific serum antibodies were described in patients with inflammatory bowel disease and their yet healthy first-degree relatives. In the latter, serum antibodies are commonly regarded as potential markers of disease susceptibility. The present long-term follow-up study evaluated the fate of antibody-positive first-degree relatives. PATIENTS AND METHODS: 25 patients with Crohn's disease, 19 patients with ulcerative colitis and 102 first-degree relatives in whom presence of ASCA, pANCA, pancreatic- and goblet-cell antibodies had been assessed were enrolled. The number of incident cases with inflammatory bowel disease was compared between antibody-positive and antibody-negative first-degree relatives 7 years after storage of serum samples. RESULTS: 34 of 102 (33%) first-degree relatives were positive for at least one of the studied serum antibodies. In the group of first-degree relatives, one case of Crohn's disease and one case of ulcerative colitis were diagnosed during the follow-up period. However, both relatives did not display any of the investigated serum antibodies (p=1). DISCUSSION: The findings of our pilot study argue against a role of serum antibodies as a marker of disease susceptibility in first-degree relatives of patients with inflammatory bowel disease. However, these data have to await confirmation in larger ideally prospective multicenter studies before definite conclusions can be drawn.

Prevalence of the -295 T-to-C promoter polymorphism of the interleukin (IL)-16 gene in periodontitis.

Interleukin (IL)-16 is involved in the regulation of the expression of several proinflammatory cytokines, i.e. tumour necrosis factor (TNF)alpha and interleukin (IL)-1beta. The present study aimed to determine the prevalence of the -295 promoter polymorphism of the interleukin (IL)-16 gene in periodontal disease. A total of 123 patients with periodontal disease and 122 healthy controls were genotyped for the -295 IL-16 promoter polymorphism. Genotyping has been performed by PCR and restriction fragment length polymorphism (RFLP) analysis. The frequencies of alleles and genotypes as well of haplotypes within both study groups were compared using the Pearson chi(2) test at a level of significance of 5% (P < 0.05). The distribution of genotypes for the -295 IL-16 gene polymorphism showed no significant difference between periodontitis patients and healthy control subjects (P = 0.886). Also stratification analysis according to the disease severity revealed no significant difference regarding the genotype distribution among both study groups. Herein the IL-16 -295 gene polymorphism was not associated with chronic periodontitis.

Accuracy of electronic apex locators in comparison to actual length--an in vivo study.

OBJECTIVES: The measurement precision of four electronic apex locators (Root ZX, Morita, Tokyo, Japan; Endy, Loser, Leverkusen, Germany; Justy II, Hager-Werken, Duisburg, Germany; Endox Lysis, Milan, Italy) was examined in the present in vivo study. METHODS: The root canal length of 40 single-rooted and multi-rooted teeth was determined with the four devices prior to tooth extraction. To determine the actual root canal length, the apical third was longitudinally sectioned, the root canal instrument was positioned and the apex was examined using a microscope. RESULTS: The average measurement deviation (+/-SD) in relation to the apical constriction was 0.3 mm (+/-0.6) for the Root ZX, 0.7 mm (+/-1.0) for the Endy, 0.2 mm (+/-0.7) for the Justy II and 1.3 mm (+/-1.7) for the Endox. The limit of +/-0.5 mm from the apical constriction was attained by the Root ZX in 78%, by the Endy in 67%, by the Justy II in 80% and by Endox in 31% of all measurements. CONCLUSIONS: The latest generation of apex locaters provide the clinician with an accurate and useful adjunct for the determination of root canal length.

Polymorphisms in the DLG5 and OCTN cation transporter genes in Crohn's disease.

BACKGROUND AND AIMS: Recent data suggest identification of causal genetic variants for inflammatory bowel disease in the DLG5 gene and in the organic cation transporter (OCTN) cluster, both situated in previously described linkage regions. PATIENTS AND METHODS: The polymorphisms in DLG5 (113 G-->A, 4136 C-->A, and DLG5_e26), SLC22A4 (1672 C-->T), and SLC22A5 (-207 G-->C) were assessed in 625 patients with Crohn's disease (CD), 363 patients with ulcerative colitis (UC), and 1012 healthy controls. Association with disease susceptibility, clinical phenotypes, and possible genetic interactions of these polymorphisms with disease associated CARD15/NOD2 mutations was analysed. RESULTS: No significant association of DLG5 polymorphisms with CD or UC was observed. Homozygosity for the OCTN-TC haplotype was associated with an increased CD risk (OR = 1.65), which was even greater in the presence of CARD15 mutations. Genotype-phenotype analysis revealed that this association was particularly strong in patients with colonic disease. The TC haplotype was associated with non-fistulising non-fibrostenotic disease, an earlier age of disease onset, and reduced need for surgery. CONCLUSION: Our observations argue against a role of DLG5 polymorphisms in the susceptibility for inflammatory bowel disease, whereas the OCTN polymorphisms are associated with CD. However, due to the comparable weak association observed herein, extended linkage disequilibrium analyses of these variants with the IBD5 haplotype tagged single nucleotide polymorphims might be advisable before definitive conclusions about their causative role in CD can be drawn.

Prevention of oral diseases.

The different types of hard- and soft tissues that are involved in the formation of the oral cavity are subject of numerous diseases. Albeit dental caries and periodontitis comprise the most common oral disease entities, also several premalignant and malignant conditions can occur within the oral cavity. There exists are wide armamentarium for the prevention of both, dental caries and periodontitis. Preventive strategies are even more important regarding oral malignancies since specifically these entities commonly provide only poor prognosis if not treated in early stages. The present contribution aims to present the pathogenic background of the most common oral diseases and the most effective methods for their prevention.

Toll-like receptor (TLR) 2 and 4 mutations in periodontal disease.

Toll-like receptors (TLR) are signal molecules essential for the cellular response to bacterial cell wall components. Different functional effective polymorphisms for the TLR 4 gene (Asp299Gly; Thr399Ile) and for the TLR 2 gene (Arg677Trp, Arg753Gln) have recently been described that are associated with impaired lipopolysaccharide signal transduction. A total of 122 patients with chronic periodontal disease and 122 healthy unrelated controls were genotyped for the Asp299Gly and Thr399Ile polymorphism of the TLR 4 gene and the Arg677Trp and Arg753Gln mutation of the TLR 2 gene. The mutations were identified with polymerase chain reaction followed by restriction fragment length polymorphism (RFLP) analysis. The prevalence of the Asp299Gly and the Thr399Ile mutant allele was 4.1% (10/244) and 4.5% (11/244) among periodontitis patients. For the healthy controls the prevalence was 3.3% (8/244) for the Asp299Gly (P = 0.810) and 3.7% (9/244) for the Thr399Ile mutant allele (P = 0.819). The Arg753Gln mutant allele was found in 2.9% (7/244) of the periodontitis subjects as compared to 4.1% (10/244) in the control group (P = 0.622). The Arg677Trp mutant allele was not found in any of the study subjects. Unlike in ulcerative colitis there was not observed an association between chronic periodontitis and the various mutations of the TLR 2 and 4 gene.

Toxicokinetic of HEMA in guinea pigs.

OBJECTIVE: Unconverted 2-hydroxyethylmethacrylate (HEMA) can be released from dental resin materials and can enter the body in humans. In the present study the uptake, distribution and excretion of 14C-HEMA applied via different routes were examined in vivo in guinea pigs. METHODS: HEMA (0.02 mmol/kg bw labelled with a tracer dose 14C-HEMA 0.3 Bq/g bw) was administered by gastric tube or by subcutaneous injection. Urine, feces, and exhaled carbon dioxide were collected for 24 h after administration. Guinea pigs were killed 24 h after the beginning of the experiment and various organs removed and 14C radioactivity measured. RESULTS: Low fecal 14C levels (about 2% of the dose) and urinary levels of about 15% after 24 h were noted with either route of administration. Direct measurement of exhaled CO(2) showed that about 70% of the dose left the body via the lungs. Two pathways for the metabolism of 14C-HEMA can be described. It is likely that 14C-pyruvate is formed in vivo resulting in the formation of toxic 14C-HEMA intermediates. 14C-HEMA was taken up rapidly from the stomach and small intestine after gastric administration and was widely distributed in the body following administration by each of the routes. CONCLUSIONS: Clearance from most tissues following gastric and intradermal administration was essentially complete within one day. The peak HEMA levels in all tissues examined after 24 h were at least onemillion-fold less than known toxic levels.

Clinical performance of a resin-modified glass-ionomer and a compomer in restoring non-carious cervical lesions. 5-year results.

PURPOSE: To evaluate the 5-yr clinical performance of a resin-modified glass-ionomer cement and a polyacid-modified resin composite in restoring non-carious cervical lesions. MATERIALS AND METHODS: Non-carious cervical lesions in 46 incisors, canines, and premolars were restored either with Fuji II LC (n=18) or with Dyract (n=28) in 16 healthy patients. The lesions were restored without cavity preparation strictly according to the manufacturer's instructions. The restorations were clinically evaluated single blind after 5 yrs using modified USPHS criteria. RESULTS: The percentage of Alfa ratings were as follows (Dyract/Fuji II LC): color match 81.3%/28.6%, surface texture 93.8%/21.4%, anatomic form 75.0%/28.6%, marginal integrity (enamel) 62.5%/42.9%, marginal integrity (dentin) 68.8%/28.6%, marginal discoloration (enamel) 56.3%/42.9%, marginal discoloration (dentin) 68.8%/21.5%. Five-yr data revealed a significant difference between the clinical ratings of Dyract and Fuji II LC for all criteria except marginal integrity and marginal discoloration in enamel. A total of five Dyract restorations and four Fuji II LC restorations failed within the study period. CLINICAL SIGNIFICANCE: A considerably high and almost similar overall failure rate was found for both restorative materials in restoring non-carious cervical lesions. However, retained Dyract restorations presented superior clinical performance compared to Fuji II LC restorations.