Genes expressed in dental enamel development are associated with molar-incisor hypomineralization

Genetic disturbances during dental development influence variation of number and shape of the dentition. In this study, we tested if genetic variation in enamel formation genes is associated with molar-incisor hypomineralization (MIH), also taking into consideration caries experience. DNA samples from 163 cases with MIH and 82 unaffected controls from Turkey, and 71 cases with MIH and 89 unaffected controls from Brazil were studied. Eleven markers in five genes [ameloblastin (AMBN), amelogenin (AMELX), enamelin (ENAM), tuftelin (TUFT1), and tuftelin-interacting protein 11 (TFIP11)] were genotyped by the TaqMan method. Chi-square was used to compare allele and genotype frequencies between cases with MIH and controls. In the Brazilian data, distinct caries experience within the MIH group was also tested for association with genetic variation in enamel formation genes. The ENAM rs3796704 marker was associated with MIH in both populations (Brazil: p = 0.03; OR = 0.28; 95% C.I. = 0.06–1.0; Turkey: p = 1.22e?012; OR = 17.36; 95% C.I. = 5.98–56.78). Associations between TFIP11 (p = 0.02), ENAM (p = 0.00001), and AMELX (p = 0.01) could be seen with caries independent of having MIH or genomic DNA copies of Streptococcus mutans detected by real time PCR in the Brazilian sample. Several genes involved in enamel formation appear to contribute to MIH.     

Genetic and immunological markers predict titanium implant failure: a retrospective study

This study evaluates diagnostic markers to predict titanium implant failure. Retrospectively, implant outcome was scored in 109 subjects who had undergone titanium implant surgery, IL1A ?889 C/T (rs1800587), IL1B +3954 C/T (rs1143634), IL1RN +2018 T/C (rs419598) and TNFA ?308 G/A (rs1800629) genotyping, in vitro IL-1β/TNF-α release assays and lymphocyte transformation tests during treatment. TNF-α and IL-1β release on titanium stimulation were significantly higher among patients with implant loss (TNF-α: 256.89 pg/ml vs. 81.4 pg/ml; p < 0.0001; IL-1β: 159.96 pg/ml vs. 54.01 pg/ml; p < 0.0001). The minor alleles of the studied polymorphisms showed increased prevalence in the implant failure group (IL1A: 61% vs. 42.6% in controls, IL1B: 53.7% vs. 39.7% in controls, TNFA: 46.3% vs. 30.9% in controls, IL1RN: 58.5% vs. 52.9% in controls). Increasing numbers of risk genotypes of the studied polymorphisms were associated with an increasing risk of implant loss, suggesting an additive effect. Multiple logistic regression analysis showed positive IL-1β/TNF-α release assay scores (p < 0.0001, OR = 12.01) and number of risk genotypes (p < 0.046, OR = 1.57–6.01) being significantly and independently associated with titanium implant failure. IL-1/IL1RN/TNFA genotyping and cytokine release assay scores provide prognostic markers for titanium implant outcome and may present new tools for individual risk assessment.     

BMP2 and BMP4 variations and risk of non-syndromic cleft lip and palate

ObjectiveNon-syndromic cleft lip with or without cleft palate (CL/P) is one of the most common congenital anomalies and arises from the interaction of environmental and genetic factors. The objective of this study was to investigate the association between the BMP2 (bone morphogenetic protein 2) and BMP4 (bone morphogenetic protein 4) polymorphisms with non-syndromic CL/P to clarify the potential role of these genes in the etiology of CL/P in Iranian population.DesignThe allelic and genotypic frequencies of BMP2 rs235768 A > T and BMP4 rs17563 T > C polymorphisms were determined in 107 unrelated Iranian subjects with non-syndromic CL/P and 186 control subjects using PCR and RFLP methods, and the results were compared with healthy controls. A p-value of <0.05 was considered statistically significant.ResultsThe BMP2 rs235768 AT genotype was significantly higher (P = 0.009, OR = 3, 95% CI = 1.3–7.0) in the CL/P (59.8%) than the control group (33.3%). Similarly, the BMP4 rs17563 TC genotype were significantly higher (P = 0.008, OR = 3.7, 95% CI = 1.4–9.9) in the CL/P (70.0%) than the control group (44.6%).ConclusionThe BMP2 rs235768 A > T and BMP4 rs17563 T > C polymorphisms could be considered as the risk factor for non-syndromic CL/P in Iranian population.     

Association study for the role of Matrix metalloproteinases 2 and 3 gene polymorphisms in dental caries susceptibility

ObjectiveVarious exogenous and endogenous risk factors have been described as contributing to dental caries susceptibility. In the last decade it has been established that both pro and active forms of host derived Matrix metalloproteinases (MMPs) are present in the oral cavity. MMPs role in caries development has been hypothesized. The aim of this study was to analyse MMP2 (rs2287074) and MMP3 (rs679620) single nucleotide polymorphisms (SNPs) and their role in caries susceptibility.DesignThe two SNPs were analysed by PCR- restriction fragment length polymorphism (RFLP) in a sample of 102 ethnic Bulgarian volunteers (42 males and 60 females), all students in Sofia Medical University.ResultsStatistical analysis of the MMP2 SNP showed significant differences for the genotype frequencies between the caries free (CF, DMFT = 0) and low caries experience (LCE, DMFT ≤ 5) groups. Analysis for the non-synonymous MMP3 SNP found significant differences between both CF vs caries experience groups (LCE+ high caries experience (HCE, DMFT ≥ 5)) and LCE vs HCE groups. The presence of allele G decreased the risk of HCE about 4 times.ConclusionsMMP2 and MMP3 genes are likely to be involved in caries susceptibility in our population. However, as dental caries is a multifactorial disorder and several genes are likely to have influence on it, it is reasonable to expect that SNPs, even those proven to be functional like rs679620, potentially play a significant, but not major role in the disease outcome.     

Randomized clinical trial on effectiveness of silver diamine fluoride and glass ionomer in arresting dentine caries in preschool children

ObjectiveTo compare the effectiveness of annual topical application of silver diamine fluoride (SDF) solution, semi-annual topical application of SDF solution, and annual application of a flowable high fluoride-releasing glass ionomer in arresting active dentine caries in primary teeth.MethodsA total of 212 children, aged 3–4 years, were randomly allocated to one of three groups for treatment of carious dentine cavities in their primary teeth: Gp1-annual application of SDF, Gp2-semi-annual application of SDF, and Gp3-annual application of glass ionomer. Follow-up examinations were carried out every six months to assess whether the treated caries lesions had become arrested.ResultsAfter 24 months, 181 (85%) children remained in the study. The caries arrest rates were 79%, 91% and 82% for Gp1, Gp2 and Gp3, respectively (p = 0.007). In the logistic regression model using GEE to adjust for clustering effect, higher caries arrest rates were found in lesions treated in Gp2 (OR = 2.98, p = 0.007), those in anterior teeth (OR = 5.55, p < 0.001), and those in buccal/lingual smooth surfaces (OR = 15.6, p = 0.004).ConclusionAnnual application of either SDF solution or high fluoride-releasing glass ionomer can arrest active dentine caries. Increasing the frequency of application to every 6 months can increase the caries arrest rate of SDF application.Clinical significanceArrest of active dentine caries in primary teeth by topical application of SDF solution can be enhanced by increasing the frequency of application from annually to every 6 months, whereas annual paint-on of a flowable glass ionomer can also arrest active dentine caries and may provide a more aesthetic outcome.     

Polymorphisms in genes involved in enamel development are associated with dental fluorosis

ObjectiveTo evaluate the association between polymorphisms in DLX1, DLX2, MMP13, TIMP1 and TIMP2 genes with dental fluorosis (DF) phenotype.DesignFour hundred and eighty one subjects (108 with DF and 373 DF free) from 6 to 18 years of age were recruited. This population lived in Rio de Janeiro, a city with fluoridation of public water supplies. DF was assessed using the Deańs index modified. Only erupted permanent teeth were assessed. Genetic polymorphisms in DLX1, DLX2, MMP13, TIMP1 and TIMP2 were analyzed by real-time PCR from genomic DNA. Association between DF, genotype, and allele distribution were evaluated using chi-square and logistic regression analyses with an alpha level of 5%.ResultsDF was more prevalent in Afro-descendants than in Caucasians (p = 0.08; OR = 1.83; CI 95% = 1.18–2.82). Logistic regression analysis adjusted by the ethnicity demonstrated a statistical difference for TIMP1 genotype (p = 0.033; OR = 2.93, 95%CI, 1.09–7.90). When only the severer cases of DF were analyzed, polymorphisms in DLX1 and DLX2 were associated with DF (p < 0.05).ConclusionOur results provided evidence that polymorphisms in TIMP1, DLX1 and DLX2 genes may be associated with DF phenotypes.     

Association between MAFB rs17820943 and rs6072081 polymorphism and risk of nonsyndromic cleft lip with or without cleft palate: a meta-analysis

While there have been previous studies examining the relation between the rs17820943 and rs6072081 polymorphisms in the v-maf musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB) gene and rates of nonsyndromic cleft lip with or without cleft palate (NSCL/P), at present the results of these studies have been inconsistent. This meta-analysis therefore aimed to conduct a more robust assessment of the association between the MAFB rs17820943 and rs6072081 polymorphisms and NSCL/P risk. The Embase, Web of Science, PubMed, the China National Knowledge Internet (CNKI), and Wanfang databases were systematically searched to identify relevant studies. In total, five studies incorporating 2769 patients and 2885 controls were identified assessing the rs17820943 polymorphism and three studies incorporating 1242 patients and 1310 controls assessing the rs6072081 polymorphism were identified. This analysis revealed the MAFB rs17820943 and rs6072081 polymorphisms to be linked to a significantly reduced NSCL/P risk (rs17820943: C vs T: OR = 0.76, 95% CI = 0.70-0.82; CC vs CT: OR = 0.75, 95% CI = 0.67-0.85; CC vs TT: OR = 0.58, 95% CI = 0.49-0.67; CC + CT vs TT: OR = 0.67, 95% CI = 0.59-0.77; CT + TT vs CC: OR = 1.43, 95% CI = 1.28-1.60; rs6072081: A vs G: OR = 0.77, 95%CI = 0.68-0.86; AA vs AG: OR = 0.76, 95%CI = 0.64-0.90; AA vs GG: OR = 0.58, 95%CI = 0.45-0.74; AA + AG vs GG: OR = 0.68, 95%CI = 0.54-0.84; AG + GG vs AA: OR = 1.40, 95% CI = 1.19-1.65). The results of the present meta-analysis indicate that in an East Asian population, for both rs17820943 and rs6072081 were associated with NSCL/P.     

Antimicrobial peptides in saliva of children with severe early childhood caries

ObjectiveControversies exist regarding the relationship between the concentrations of antimicrobial peptides (AMPs) and presence of dental caries in children. Thus, the aim of this study was to examine levels of AMPs in saliva of caries-free (CF), early childhood caries (ECC) and severe early childhood caries (S-ECC) children to determine if the levels of these salivary peptides individually or in combinations were related to caries severity and mutans streptococci levels.Design36 to 60 month-old children were selected to participate in this study. Children were grouped into CF group (n = 29), ECC group (n = 25) and S-ECC group (n = 29). Saliva was collected from children for microbiological analysis by culture. Salivary concentrations of cathelicidin LL-37, human β-defensin 2 (hBD-2), human β-defensin 3 (hBD-3) and histatin-5 (HTN-5) were determined by ELISA.ResultsSalivary concentrations of AMPs did not differ among CF, ECC and S-ECC groups. Data showed positive correlations between mutans streptococci levels and salivary hBD-2 or HTN-5. Positive correlations were found between hBD-2, hBD-3, LL-37 and HTN-5. Combinations among AMPs, mainly LL-37, were positively associated with caries levels.ConclusionsSalivary concentrations of AMPs individually were not associated with the severity of early childhood caries. The stimulus of caries appears to trigger a biological response, however, with a combination of these peptides.     

Influence of tumour necrosis factor alpha on epithelial–mesenchymal transition of oral cancer cells in co-culture with mesenchymal stromal cells

Tumour progression in head and neck squamous cell carcinoma (HNSCC) is influenced by the surrounding stroma and inflammatory cytokines such as tumour necrosis factor alpha (TNF-α). The aim of this study was to test the hypothesis that TNF-α modulates the interactions of HNSCC cell line PCI-13 and bone marrow mesenchymal stromal cells (BMSCs) and influences markers of epithelial–mesenchymal transition (EMT). Following induction with TNF-α, mono- and co-cultures of BMSCs and the established HNSCC cell line PCI-13 were analyzed; protein expression of E-cadherin and vimentin and qRT-PCR expression of Snail, Twist, MMP14, vimentin, E-cadherin, and β-catenin were examined, and changes in cellular AKT signalling were analyzed. TNF-α induced a significant decrease in E-cadherin (64.5 ± 6.0%, P = 0.002) and vimentin (10.4 ± 3.5%, P = 0.04) protein expression in co-cultured PCI-13, while qRT-PCR showed a significant increase in β-catenin (BMSCs P < 0.0001; PCI-13 P = 0.0005) and Snail (BMSCs P = 0.009; PCI-13 P = 0.01). TNF-α also resulted in a down-regulation of AKT downstream targets S6 (38.7 ± 20.9%, P = 0.01), p70S6 (16.7 ± 12%, P = 0.05), RSK1 (23.6 ± 28.8%, P = 0.02), and mTOR (27.4 ± 17.5%, P = 0.004) in BMSC co-cultures. In summary, while reducing the expression of vimentin and AKT-signalling in PCI-13 and BMSC, respectively, TNF-α introduced an inflammatory-driven tumour–stroma transition, marked by an increased expression of markers of EMT.     

Association of interferon-gamma gene polymorphisms with susceptibility to oral lichen planus in the Thai population

ObjectiveInterferon-gamma (IFN-γ) is highly expressed in oral lichen planus (OLP). The IFN-γ (+874 in intron 1, rs2430561) TT genotype, which has been reported to be associated with high IFN-γ production, was hypothesized to be associated with susceptibility to OLP in the Thai population.DesignGenomic DNA samples from 74 OLP and 268 healthy controls were evaluated for IFN-γ polymorphisms by polymerase chain reaction with sequence-specific primers (PCR-SSP) and direct sequencing method.ResultsThe T allele was significantly associated with an increased risk of OLP development as compared to the A allele (OR = 1.76, P = 0.004; P_c = 0.02). The effect of the T allele was similar to an autosomal recessive disorder; the presence of TT genotype (when compared to AA and AT) conferred an OR of 2.61, P = 0.008; P_c = 0.04.ConclusionsWe found an association between IFN-γ +874A/T polymorphism and susceptibility to OLP. However, an association study utilising a larger sample size and patients from other races apart from the Asian population should be performed to further verify these findings.     

Are clustering effects accounted for in statistical analysis in leading dental specialty journals?

ObjectivesIn dental research multiple site observations within patients or taken at various time intervals are commonplace. These clustered observations are not independent; statistical analysis should be amended accordingly. This study aimed to assess whether adjustment for clustering effects during statistical analysis was undertaken in five specialty dental journals.MethodsThirty recent consecutive issues of Orthodontics (OJ), Periodontology (PJ), Endodontology (EJ), Maxillofacial (MJ) and Paediatric Dentristry (PDJ) journals were hand searched. Articles requiring adjustment accounting for clustering effects were identified and statistical techniques used were scrutinized.ResultsOf 559 studies considered to have inherent clustering effects, adjustment for this was made in the statistical analysis in 223 (39.1%). Studies published in the Periodontology specialty accounted for clustering effects in the statistical analysis more often than articles published in other journals (OJ vs. PJ: OR = 0.21, 95% CI: 0.12, 0.37, p < 0.001; MJ vs. PJ: OR = 0.02, 95% CI: 0.00, 0.07, p < 0.001; PDJ vs. PJ: OR = 0.14, 95% CI: 0.07, 0.28, p < 0.001; EJ vs. PJ: OR = 0.11, 95% CI: 0.06, 0.22, p < 0.001). A positive correlation was found between increasing prevalence of clustering effects in individual specialty journals and correct statistical handling of clustering (r = 0.89).ConclusionsThe majority of studies in 5 dental specialty journals (60.9%) examined failed to account for clustering effects in statistical analysis where indicated, raising the possibility of inappropriate decreases in p-values and the risk of inappropriate inferences.     

Rs12941170 at SOX9 gene associated with orofacial clefts in Chinese

ObjectiveNon-syndromic orofacial cleftings (NSOCs) are considered as complex trait, which results from genetic and/or environmental modifiers. Current findings could only explain small portion of the NSOCs. SOX9 gene plays an important role during craniofacial development in animal models and the Pierre Robin sequence (PRS). However, its role in non-syndromic clefts remains unknown.DesignIn this study, we selected eight SNPs in and around SOX9 gene to make maximum coverage, and genotyped them by using RFLP-PCR and ligase detection reaction (LDR) methods to test its associations among 151 NSOCs (53 NSCLP, 52 NSCLO and 46 NSCPO) from Western Han Chinese population.ResultsAllelic TDT results showed that G allele at rs12941170 of SOX9 was under-transmitted among NSOCs (p = 0.00014, OR = 0.55 and 95%CI: 0.40–0.75), which could indicate that the G allele is protective against NSOCs; parent-of-origin effect analysis showed that G allele at rs12941170 was maternally under-transmitted (p = 0.002), while there was no statistically difference between the maternal and paternal transmission of it. To test if the adjacent SNPs travel together from parents to the affected individual, we carried out the sliding window haplotype analysis, it is interesting to find that the haplotypes carrying the G allele at rs12941170 also was under-transmitted for NSOCs, NSCL/P, NSCLP and NSCPO (lowest p = 0.00033).ConclusionsThis study suggested that G allele at rs12941170 was protective, which could decrease the risk for NSOCs from Western Han Chinese population, and it will provide new reference for future research and genetic counseling in NSOCs.     

Association of ENAM gene single nucleotide polymorphisms with dental caries in Polish children

Objectives

The objective of this study was to prove the association between dental caries and single nucleotide polymorphisms (SNPs) in the ENAM gene.

Material and methods

The research was carried out in 96 children (48 with caries and 48 counterparts free of this disease), aged 20–42 months, with 11–20 erupted teeth. All children were from four day nurseries located in Poznan. The study included the dental examination to select individuals to the research and oral swab collection for molecular evaluation. Seven selected SNPs markers of the ENAM gene were genotyped, five using TaqMan probe assay (rs2609428, rs7671281, rs36064169, rs3796704, and rs12640848) and two by Sanger sequencing (rs144929717 and rs139228330).

Results

Statistically significant higher prevalence of the alternative G allele and the alternative GG homozygote in the control group in comparison with the caries group in SNP rs12640848 was observed, respectively, p = 0.0062 and 0.0010. Although the prevalence of the AG heterozygote was higher for the caries subjects in comparison with controls (OR = 2.9), and the result was statistically significant (p = 0.0010), the overall prevalence of the G allele for this SNP was significantly higher in control group (OR = 2.3; p = 0.0062).

Conclusions

The study revealed the strong association between rs12640848 marker of ENAM gene and caries susceptibility in primary teeth in children from Poznan.

Clinical relevance

The presence of SNPs in the ENAM gene may be important as suspected predictive factor of dental caries occurrence in children.

     

Influence of abutment-to-fixture design on reliability and failure mode of all-ceramic crown systems

ObjectiveEvaluate the effect of implant connection designs on reliability and failure modes of screw-retained all-ceramic crowns.MethodsCentral incisor ceramic crowns in zirconia abutments were screwed and torqued down to external hexagon (EH), internal hexagon (IH) and Morse taper (MT) implant systems. Single-load-to-fracture (SLF) test (n = 4 per group) determined three step-stress fatigue profiles with specimens assigned in the ratio of 3:2:1. Fatigue test was performed under water at 10 Hz. Use level probability Weibull curves and reliability for missions of 50,000 cycles at 400 N and 200 N were calculated (90% confidence bounds-CB). Weibull probability distribution (90% CB) was plotted (Weibull modulus vs characteristic strength) for comparison between the groups. Fractographic analyses were conducted under polarized-light microscopy and SEM.ResultsUse level Weibull probability calculation indicated that failure was not associated with fatigue in groups EH (β = 0.63), IH (β = 0.97) and MT (β = 0.19). Reliability data for a mission of 50,000 cycles at 400 N revealed significant reliability differences between groups EH (97%), IH (46%) and MT (0.5%) but no significant difference at 200 N between EH (100%) and IH (98%), and IH and MT (89%). Weibull strength distribution (figure) revealed β = 13.1/η = 561.8 for EH, β = 5.8/η = 513.4 for IH and β = 5.3/η = 333.2 for MT. Groups EH and IH exhibited veneer cohesive and adhesive failures. Group IH also presented adhesive failure at zirconia/titanium abutment insert while MT showed fracture at abutment neck.SignificanceAlthough group EH presented higher reliability and characteristic strength followed by IH and MT, all groups withstood reported mean anterior loads.     

Sex differentials in caries frequencies in Medieval London

ObjectiveTooth decay is one of the most common oral infections observed in skeletal assemblages. Sex differentials in caries frequency are commonly examined, with most studies finding that females tend to have a higher frequency of carious lesions (caries) compared to males. Less research has examined differences in caries between males and females with respect to age in past populations. Findings from living populations indicate that caries frequencies are higher in females, at least in part, because of the effects of estrogen and pregnancy. We are interested in the interaction of age, sex, and caries in medieval London, during a period of repeated famines, which might have exacerbated underlying biological causes of caries sex differentials.DesignWe examined caries in adults from two medieval London cemeteries dating to c. 1120–1539 AD: St. Mary Spital (n = 291) and St. Mary Graces (n = 80) to test the hypothesis that males and females have different caries frequencies irrespective of age. The association between maxillary molar caries and sex was tested using hierarchical log-linear analysis to control for the effects of age on caries frequencies.ResultsThe results indicate a higher frequency of maxillary molar caries in females (P < 0.00), and that the age distribution of caries differs between the sexes (P = 0.01), with a consistent increase in frequency with age for females until late adulthood, but not males.ConclusionsThe difference in caries frequencies is not explained by differences in the age distributions of the sexes. Differences in the age patterns of caries for males and females could be the result of biological factors that present during reproductive age, differences in diet, or differential access to resources during famine.     

Evaluation of the gingival inflammation in pregnancy and postpartum via 25-hydroxy-vitamin D3, prostaglandin E2 and TNF-α levels in saliva

BackgroundPhysiological changes and immunological modifications occur during pregnancy. The clinical and biological features of periodontal infections are affected by pregnancy. The aim of the present study was to evaluate saliva levels of 25-hydroxy-vitamin D3 (25(OH)D3), prostaglandin E2 (PGE₂) and TNF-alpha (TNF-α) in pregnancy, postpartum and non-pregnant controls.MethodsWhole saliva samples together with full-mouth clinical periodontal recordings were obtained from 59 pregnant, 47 post partum and 70 systemically healthy non-pregnant women. Groups were also evaluated according to the periodontal health status. 25(OH)D3, PGE₂ and TNF-α levels in the saliva samples were determined by enzyme-linked immunoassays. Data were statistically tested by nonparametrical tests.ResultsSaliva TNF-α and PGE₂ levels were significantly lower and 25(OH)D3 levels were significantly higher in the pregnant group than postpartum group (p < 0.0001). Saliva TNF-α and 25(OH)D3 levels were significantly higher and PGE₂ levels were significantly lower in the control group than postpartum group (p < 0.0001). In the pregnant healthy, gingivitis and periodontitis groups saliva TNF-α levels were significantly lower than postpartum and control counterparts (p < 0.0001, p = 0.032, p = 0.003 and p = 0.013; p = 0.027; p = 0.007, respectively). In control healthy, gingivitis and periodontitis groups saliva 25(OH)D3 levels were significantly higher than the postpartum counterparts (p < 0.0001, p < 0.0001, p = 0.002, respectively). In the control healthy and gingivitis groups saliva 25(OH)D3 levels were significantly higher than pregnant healthy and gingivitis (p < 0.0001).ConclusionsIn conclusion, within the limits of the present study it seems that pregnancy have an effect on parameters in saliva in relation to the periodontal status of the women. Further studies are required for better understanding of the impact of periodontal diseases on pregnancy or otherwise.     

The absence of an association between Interleukin 1β gene polymorphisms and recurrent aphthous stomatitis (RAS)

ObjectivesRecurrent aphthous stomatitis (RAS) is a chronic, ulcerative disease with a probable polygenic mode of inheritance and complex etiology with a strong immunological background. The aim of the present study was to determine the possible association between two single nucleotide polymorphisms (SNPs) of the IL-1β gene: IL-1β − 511 T > C (rs16944) and IL-1β + 3954C > T (rs1143634) and RAS susceptibility in a moderately large group of patients.DesignOne hundred and four patients with minor, major and herpetiform RAS and 75 healthy volunteers were genotyped at IL-1β − 511 T > C (rs16944) and IL-1β + 3954C > T (rs1143634) using the PCR-RFLP approach. The results were statistically analysed with chi-square test and test of difference between two rates of structure, with p < 0.05 assumed to be a statistically significance level (Statistica 10, StatSoft^®, Kraków, Poland).ResultsThere were no statistically significant differences in the genotype distribution for the IL-1β C[+3954]T polymorphism between the RAS and control groups. The frequency of IL-1β*T[-511]/*T[–511] homozygotes among the patients was significantly higher when compared to our study control (p < 0.0347). The results after stratification into carriers and non-carriers of C and T alleles did not clearly indicate which SNP may be considered a risk factor for RAS.ConclusionsThe genetic association between the studied SNPs of the IL-1β gene and RAS remains controversial and requires further investigation.     

DEFB1 polymorphisms and salivary hBD-1 concentration in Oral Lichen Planus patients and healthy subjects

ObjectivesThe aetiology of Oral Lichen Planus (OLP), a chronic inflammatory disease of oral mucosa, is not yet well understood. Since innate immunity may be hypothesized as involved in the susceptibility to OLP, we studied human beta defensin 1 (hBD-1) an antimicrobial peptide constitutively expressed in the saliva, looking at functional genetic variants possibly able to diminish hBD-1 production an consequently conferring major susceptibility to OLP.DesignWe analysed three DEFB1 polymorphisms at 5′ UTR, −52G > A (rs1799946), −44C > G (rs1800972), −20G > A (rs11362) and two DEFB1 polymorphisms at 3′UTR, c*5G > A (rs1047031), c*87A > G (rs1800971), with the aim of correlating these genetic variants and hBD-1 salivary level in a group of OLP patients and in healthy subjects. We also evaluated hBD-1 salivary concentrations, using ELISA, in OLP and healthy controls.ResultsWe compared hBD-1 concentrations in OLP and healthy subjects: hBD-1 concentration was significantly higher in OLP patients respect to control.When considering the correlation between DEFB1 polymorphisms genotypes and hBD-1 expression levels, significant results were obtained for SNPs −52G > A (p = 0.03 both in OLP patients and healthy individuals) and −44C > G (p = 0.02 in OLP patients).ConclusionshBD-1 production was different between OLP and healthy subjects (not age-matched with OLP). DEFB1 gene polymorphisms, −52G > A and −44C > G, correlated with hBD-1 salivary concentrations.     

Effect of tumor necrosis factor alpha (TNF-α) -308 and -1031 gene polymorphisms on periodontitis among Saudi subjects

ObjectivesPeriodontitis is an infectious disorder that leads to irreversible loss of the surrounding attachment and bone destruction. Genetic polymorphism of cytokines has been suggested to play a role in periodontitis. This case-control study aimed to investigate the relationship between periodontitis and two single nucleotide polymorphisms (SNPs): rs1800629 (-308 G/A) and rs1799964 (-1031 T/C), in the TNF-α gene promoter area.Materials and methodsPeripheral blood was used to prepare genomic DNA from 60 subjects with stage II to stage III periodontitis, as along with 65 control subjects. Polymerase chain reaction and restriction endonuclease digestion were used to genotype TNF-α SNPs.ResultsThe distribution of both genotypes and alleles of TNF-α (-308 G/A) polymorphism did not vary between periodontitis subjects and the controls (P > 0.05). However, the CT genotype and C allele of the TNF-α (-1031 T/C) polymorphism were observed more frequently in the periodontitis subjects than in the controls, while the TT genotype and the T allele were more predominant in the control subjects than in the periodontitis patients (OR: 3.149; 95% CI: 1.494–6.639; P = 0.002 and OR: 2.933; 95% CI: 1.413–6.090; P = 0.003, sequentially).ConclusionThe TNF-α (-308 G/A) polymorphism potentially has no correlation with periodontitis susceptibility, whereas the TNF-α (-1031) CT genotype and C allele might be related to periodontitis among Saudi subjects.     

Genetic association study between Interleukin 10 gene and dental implant loss

ObjectiveThree single nucleotide polymorphisms (SNPs), ?1082, ?819 and ?592, located on the promoter region of IL10 gene have been associated with high in vitro IL-10 production and autoimmune diseases. We aim to investigate whether polymorphisms in the IL10 gene would influence dental implant loss.MethodsWe evaluated a total of 277 unrelated patients, including 185 individuals presenting at least one osseointegrated implant in function for six months or more and with no implant failure, and 92 individuals presenting at least one implant loss. DNA was extracted from buccal mucosa cells and SNPs were genotyped using TaqMan^® probes-based assays.ResultsMultiple logistic regression showed association between dental implant failure with ?819(C/T) genotype (OR = 3.27; 95% CI = 1.02–10.46; p = 0.0334). However, considering the statistical significance level α = 0.004 (adjusted by Bonferroni correction of multiple comparisons), these results lost their significance. No association of dental implant loss with genotypes and alleles of the ?1082 and ?592 SNPs, as well as IL10 haplotypes in genotype/allele forms were found (p = 0.9400; p = 0.8861).ConclusionsNeither the IL10 gene polymorphisms, nor haplotypes or other covariates were associated with susceptibility to dental implant failure in the studied population.