Impact of Dietary Nitrate on the Recovery of Therapy-related Vascular Health Impairments Following Standard Periodontal Aftercare Therapy: a Hypothesis-generating Subanalysis.

This follow-up study assessed the impact of a nitrate-rich diet on salivary nitrate/nitrite levels and the recovery of therapy-induced vascular impairments in a cohort of 39 periodontitis patients treated by standard subgingival mechanical plaque removal (PMPR). At baseline, saliva samples for nitrate/nitrite analysis were collected, and peripheral/central blood and augmentation pressure was documented using the Arteriograph recording system. Immediately after, PMPR vascular parameters were reassessed. All study patients received a randomly allocated supply of a lettuce beverage to be consumed for 14 days, containing either a daily dosage of 200 mg nitrate (test group, n = 20) or being void of nitrate (placebo group, n = 19). At day 14, salivary and vascular parameters were reassessed. Initial salivary and vascular parameters did not differ significantly between the groups. PMPR impaired all vascular parameters in both groups with no differences between the groups. At day 14, salivary nitrate/nitrite levels of the test group were significantly elevated compared to baseline. All vascular parameters had significantly recovered from the impairment inflicted by PMPR. In the placebo group, by contrast, salivary parameters did not differ significantly from baseline, and the recovery of impaired vascular parameters was restricted to a significant improvement of diastolic blood pressure. Correlation analysis identified a significant inverse correlation between salivary nitrate/nitrite sum and central/peripheral blood pressure and augmentation pressure. In conclusion, the data of this subanalysis suggest that increasing salivary nitrate/nitrite levels by a diet rich in nitrate may improve recovery of therapy-induced vascular impairments after PMPR.

Impact of the uninstructed use of a herbal, ayurvedic toothpaste on parameters of gingival health in periodontal aftercare patients: A randomized, double-blinded, two-arm parallel-group study.

AIM: The aim of this study was to evaluate the impact of the uninstructed use of a toothpaste containing herbal ayurvedic ingredients on parameters of gingival health in a cohort of periodontal aftercare patients affected by gingival inflammation compared to the use of a standard, non-herbal toothpaste. MATERIALS AND METHODS: The monocentric, randomized, double-blinded, two-arm parallel-group intervention was performed in a cohort of 88 periodontal aftercare patients with clinical signs of gingival inflammation. At baseline, bleeding on probing (BoP), gingival index (GI) and Quigley-Hein plaque index (QHI) were recorded. Subsequently, the study patients were randomly provided with a herbal ayurvedic toothpaste (n = 44) or a conventional, non-ayurvedic control toothpaste (n = 44) and without additional oral hygiene training instructed to use it 2× daily for the next 28 days. On day 28, BoP, GI and QHI were recorded again. RESULTS: At baseline, there were no significant differences between both groups. On day 28, mean GI and BoP scores were significantly lower (p < 0.001) compared to baseline in both groups. Differences between the groups could not be verified. Mean QHI scores did not change significantly between day 0 and day 28 in both groups. CONCLUSIONS: The impact of uninstructed toothbrushing with an ayurvedic toothpaste on the manifestation of gingival inflammation in periodontal aftercare patients is not significantly different to the use of a conventional, non-herbal toothpaste.

Sex-specific genetic factors affect the risk of early-onset periodontitis in Europeans.

AIMS: Various studies have reported that young European women are more likely to develop early-onset periodontitis compared to men. A potential explanation for the observed variations in sex and age of disease onset is the natural genetic variation within the autosomal genomes. We hypothesized that genotype-by-sex (G × S) interactions contribute to the increased prevalence and severity. MATERIALS AND METHODS: Using the case-only design, we tested for differences in genetic effects between men and women in 896 North-West European early-onset cases, using imputed genotypes from the OmniExpress genotyping array. Population-representative 6823 controls were used to verify that the interacting variables G and S were uncorrelated in the general population. RESULTS: In total, 20 loci indicated G × S associations (P < 0.0005), 3 of which were previously suggested as risk genes for periodontitis (ABLIM2, CDH13, and NELL1). We also found independent G × S interactions of the related gene paralogs MACROD1/FLRT1 (chr11) and MACROD2/FLRT3 (chr20). G × S-associated SNPs at CPEB4, CDH13, MACROD1, and MECOM were genome-wide-associated with heel bone mineral density (CPEB4, MECOM), waist-to-hip ratio (CPEB4, MACROD1), and blood pressure (CPEB4, CDH13). CONCLUSIONS: Our results indicate that natural genetic variation affects the different heritability of periodontitis among sexes and suggest genes that contribute to inter-sex phenotypic variation in early-onset periodontitis.

Impact of 0.1% octenidine mouthwash on plaque re-growth in healthy adults: a multi-center phase 3 randomized clinical trial.

OBJECTIVES: To investigate plaque inhibition of 0.1% octenidine mouthwash (OCT) vs. placebo over 5 days in the absence of mechanical plaque control. MATERIALS AND METHODS: For this randomized, placebo-controlled, double-blind, parallel group, multi-center phase 3 study, 201 healthy adults were recruited. After baseline recording of plaque index (PI) and gingival index (GI), collection of salivary samples, and dental prophylaxis, subjects were randomly assigned to OCT or placebo mouthwash in a 3:1 ratio. Rinsing was performed twice daily for 30 s. Colony forming units in saliva were determined before and after the first rinse. At day 5, PI, GI, and tooth discoloration index (DI) were assessed. Non-parametric van Elteren tests were applied with a significance level of p < 0.05. RESULTS: Treatment with OCT inhibited plaque formation more than treatment with placebo (PI: 0.36 vs. 1.29; p < 0.0001). OCT reduced GI (0.04 vs. placebo 0.00; p = 0.003) and salivary bacterial counts (2.73 vs. placebo 0.24 lgCFU/ml; p < 0.0001). Tooth discoloration was slightly higher under OCT (DI: 0.25 vs. placebo 0.00; p = 0.0011). Mild tongue staining and dysgeusia occurred. CONCLUSIONS: OCT 0.1% mouthwash inhibits plaque formation over 5 days. It therefore can be recommended when regular oral hygiene is temporarily compromised. CLINICAL RELEVANCE: When individual plaque control is compromised, rinsing with octenidine mouthwash is recommended to maintain healthy oral conditions while side effects are limited.

Status of periodontal health in German patients suffering from chronic kidney disease-Data from the GCKD study.

AIM: To assess the prevalence and severity of periodontitis in patients with moderate chronic kidney disease (CKD) and comparing the results with the self-reported periodontitis awareness of the study subjects. MATERIAL AND METHODS: The periodontal status of 270 patients with moderate CKD randomly selected from a cohort of 5,217 subjects participating in the prospective observational German Chronic Kidney Disease (GCKD) project was analysed by recording bleeding on probing (BOP), probing pocket depth (PPD) and clinical attachment level (CAL). Furthermore, the awareness of the study subjects of their periodontal conditions was evaluated by a self-reported questionnaire. RESULTS: 24.4% of the CKD study patients showed no or only mild signs of periodontal disease, 47.6% displayed moderate and 27% severe periodontitis. Questionnaire data revealed that 62.3% of the study subjects with severe periodontitis were not aware of the presence of the disease, 44.4% denied having received any systematic periodontal therapy so far, although 50% of them indicated to visit their dentist regularly for professional tooth cleanings. CONCLUSION: While the clinical study data confirm an increased prevalence of periodontitis in CKD patients, their self-reported awareness of periodontitis was low.

A genome-wide association study identifies nucleotide variants at SIGLEC5 and DEFA1A3 as risk loci for periodontitis.

Periodontitis is one of the most common inflammatory diseases, with a prevalence of 11% worldwide for the severe forms and an estimated heritability of 50%. The disease is characterized by destruction of the alveolar bone due to an aberrant host inflammatory response to a dysbiotic oral microbiome. Previous genome-wide association studies (GWAS) have reported several suggestive susceptibility loci. Here, we conducted a GWAS using a German and Dutch case-control sample of aggressive periodontitis (AgP, 896 cases, 7,104 controls), a rare but highly severe and early-onset form of periodontitis, validated the associations in a German sample of severe forms of the more moderate phenotype chronic periodontitis (CP) (993 cases, 1,419 controls). Positive findings were replicated in a Turkish sample of AgP (223 cases, 564 controls). A locus at SIGLEC5 (sialic acid binding Ig-like lectin 5) and a chromosomal region downstream of the DEFA1A3 locus (defensin alpha 1-3) showed association with both disease phenotypes and were associated with periodontitis at a genome-wide significance level in the pooled samples, with P = 1.09E-08 (rs4284742,-G; OR = 1.34, 95% CI = 1.21-1.48) and P = 5.48E-10 (rs2738058,-T; OR = 1.28, 95% CI = 1.18-1.38), respectively. SIGLEC5 is expressed in various myeloid immune cells and classified as an inhibitory receptor with the potential to mediate tyrosine phosphatases SHP-1/-2 dependent signaling. Alpha defensins are antimicrobial peptides with expression in neutrophils and mucosal surfaces and a role in phagocyte-mediated host defense. This study identifies the first shared genetic risk loci of AgP and CP with genome-wide significance and highlights the role of innate and adaptive immunity in the etiology of periodontitis.

No differences in microbiome changes between anti-adhesive and antibacterial ingredients in toothpastes during periodontal therapy.

AIM: This subgroup analysis of a 12-week randomized, double-blind, and two-center trial aimed to evaluate whether two different toothpaste formulations can differentially modulate the dental microbiome. MATERIAL AND METHODS: Forty one mild to moderate periodontitis patients used as an adjunct to periodontal treatment either a toothpaste with anti-adhesive zinc-substituted carbonated hydroxyapatite (HA) or with antimicrobial and anti-adhesive amine fluoride/stannous fluoride (AmF/SnF2 ) during a 12-week period. Plaque samples from buccal/lingual, interproximal, and subgingival sites were taken at baseline, 4 weeks after oral hygiene phase, and 8 weeks after periodontal therapy. Samples were analyzed with paired-end Illumina Miseq 16S rDNA sequencing. The differences and changes on community level (alpha and beta diversity) and on the level of single agglomerated ribosomal sequence variants (aRSV) were calculated with analysis of covariance (ANCOVA) and likelihood ratio test (LRT). RESULTS: Interproximal and subgingival sites harbored predominately Fusobacterium and Prevotella species associated with periodontitis, whereas buccal/lingual sites harbored mainly Streptococcus and Veillonella species associated with periodontal health. Alpha and beta diversity did not change noticeably differently between both toothpaste groups (P > 0.05, ANCOVA). Furthermore, none of the aRSVs showed a noticeably different change between the tested toothpastes during periodontal therapy (Padj . > 0.05, LRT). CONCLUSION: The use of a toothpaste containing anti-adhesive HA did not induce statistically noticeably different changes on microbial composition compared to an antimicrobial and anti-adhesive AmF/SnF2 formulation.

Wild-type isolates of Porphyromonas gingivalis derived from periodontitis patients display major variability in platelet activation.

In vitro studies revealed that Porphyromonas gingivalis (Pg), a pathogen intimately associated with the onset and progression of periodontitis, is able to activate platelets, thus linking periodontal inflammation with the endangerment of vascular health. As wild-type Pg strains are characterized by major genetic heterogeneity, the commonness of platelet-activating Pg strains in periodontitis patients is unknown as of yet. Therefore, this study evaluated the platelet activation capacity of wild-type Pg isolates sampled from patients with aggressive periodontitis. METHODS: Extent and velocity of platelet aggregation were determined by light transmission aggregometry. Platelet surface expression of P-selectin was measured by flow cytometry, activation of p38 MAP kinase, and protein kinase C by Western blot using phospho-specific antibodies. RESULTS: Pg isolates displayed high variability regarding extent and velocity of platelet activation, as well as the involved activating pathways. Corresponding results were observed for platelet P-selectin expression, activation of p38 MAP kinase, or protein kinase C. Inhibitors of platelet immune receptor FcγRIIA and protease-activated receptors revealed several, diverging pathways of activation. Some isolates induced platelet aggregation even in the presence of potent therapeutical platelet inhibitors. CONCLUSIONS: Chronic bacteremia involving specific, platelet-activating Pg strains may constitute a substantial hazard for the integrity of cardiovascular health.

Impact of anti-infective periodontal therapy on parameters of vascular health.

AIM: This study assessed the impact of anti-infective periodontal therapy on the status of vascular health. MATERIALS AND METHODS: Periodontal and vascular health of 55 patients with severe untreated chronic periodontitis was evaluated before and 12 months after anti-infective periodontal therapy. Observed parameters were bleeding on probing (BoP), pocket probing depth (PPD), periodontal inflamed surface area index (PISA), pulse wave velocity (PWV), augmentation index (AIx), central pulse pressure (PPao) and peripheral systolic pressure (RRsys). RESULTS: ΔPISA (baseline-12 months) correlated with ΔPWV (τ 0.21; p < .03), ΔAIx (τ 0.29; p < .002) and ΔPPao (τ 0.23; p < .02). ΔBoP% (baseline-12 months) correlated with ΔPWV (τ 0.18; p < .05) and ΔAIx (τ 0.25; p < .01), while mean ΔPPD (baseline-12 months) correlated with ΔPWV (τ 0.24; p < .01) and ΔAIx (τ 0.21; p < .03). Grouping patients evenly into three groups based on tertiles of BoP resolution after 12 months revealed a significant decrease in the observed PWV median value by -0.6 m/s (p < .04) in the best response tertile (ΔBoP ≥ 88%). In the worst response tertile (ΔBoP ≤ 66%), by contrast, significant increase in PPao (+10.5 mmHg; p < .02) and AIx (+5.5; p < .02) was observed. CONCLUSION: Efficacious resolution of periodontal inflammation may beneficially impact on vascular health.

Impact of different concentrations of an octenidine dihydrochloride mouthwash on salivary bacterial counts: a randomized, placebo-controlled cross-over trial.

OBJECTIVES: This bi-centric, placebo-controlled, randomized, evaluator-blinded, incomplete cross-over clinical phase II trial was initialized to identify the most appropriate concentration of octenidine dihydrochloride (OCT) in mouth rinses. MATERIALS AND METHODS: Rinses of 0.10, 0.15, and 0.20% OCT were compared to a saline placebo rinse regarding the reduction of salivary bacterial counts (SBCs) in 90 gingivitis patients over 4 days. Changes in plaque (PI) and gingival index (GI), taste perception, and safety issues were evaluated. RESULTS: At baseline, the first OCT (0.10, 0.15, 0.20%) rinse resulted in a decrease of SBC (reduction by 3.63-5.44 log10 colony forming units [CFU]) compared to placebo (p < 0.001). Differences between OCT concentrations were not verified. After 4 days, the last OCT rinse again resulted in a significant SBC decrease (3.69-4.22 log10 CFU) compared to placebo (p < 0.001). Overall, SBC reduction between baseline and day 4 was significantly higher in OCT 0.15 and 0.20% groups compared to OCT 0.10% and placebo. Mean GI/PIs were significantly lower in OCT groups than in the placebo group (p < 0.001). Differences in GI/PI between OCT groups were not verified. Adverse effects increased with increasing OCT concentrations. CONCLUSIONS: Considering antibacterial efficacy, frequency of adverse events, and user acceptance, 0.10% OCT was identified as the preferred concentration to be used in future clinical trials. CLINICAL RELEVANCE: Due to its low toxicity and pronounced antibacterial properties, octenidine dihydrochloride (OCT) is a promising candidate for the use in antiseptic mouth rinses. OCT concentrations of 0.10% are recommended for future clinical trials evaluating the plaque-reducing properties of OCT mouth rinses. ( www.clinicaltrials.gov , NCT022138552).

A haplotype block downstream of plasminogen is associated with chronic and aggressive periodontitis.

AIM: The intronic variant rs4252120 in the plasminogen gene (PLG) is known to be associated with aggressive periodontitis (AgP) and atherosclerosis. Here, we examined the chromosomal region spanning PLG for associations with both chronic periodontitis (CP) and AgP. MATERIALS AND METHODS: The association of PLG candidate rs4252120 was tested in a German case-control sample of 1,419 CP cases using the genotyping assay hCV11225947 and 4,562 controls, genotyped with HumanOmni BeadChips. The German and Dutch sample of AgP cases (N = 851) and controls (N = 6,836) were genotyped with HumanOmni BeadChips. The North American CP sample (N = 2,681 cases, 1,823 controls) was previously genotyped on the Genome-Wide Human SNP Array 6.0. Genotypes were imputed (software Impute v2), and association tests were performed using an additive genetic model adjusting for sex and smoking. RESULTS: Rs4252120 was not associated with CP. However, a haplotype block downstream of PLG and not in linkage disequilibrium with rs4252120 (r2  = .08) was associated with both AgP (rs1247559; p = .002, odds ratio [OR] = 1.33) and CP (p = .02, OR = 1.15). That locus was also significantly associated with PLG expression in osteoblasts (p = 6.9 × 10-5 ). CONCLUSIONS: Our findings support a role of genetic variants in PLG in the aetiology of periodontitis.

Regular consumption of Lactobacillus reuteri-containing lozenges reduces pregnancy gingivitis: an RCT.

AIM: This randomized controlled trial assessed the impact of Lactobacillus reuteri on pregnancy gingivitis in healthy women. MATERIALS AND METHODS: Forty-five healthy women (24 test/21 placebo) with pregnancy gingivitis in the third trimester of pregnancy were enrolled. At baseline Gingival Index (GI) and Plaque Index (PlI) were assessed at the Ramfjord teeth and venous blood taken for TNF-α analysis. Subsequently participants were randomly provided with lozenges to be consumed 2 × daily until birth (approx. 7 weeks) containing ≥108 CFU L. reuteri ATCC PTA 5289 and ≥108 CFU L. reuteri DSM 17938 (test) or being devoid of L. reuteri (placebo). Within 2 days after birth recording of GI, PlI and blood sampling were repeated. RESULTS: At baseline, mean GI and mean PlI did not differ significantly between both groups. In the test group mean TNF-α serum level was significantly (p < 0.02) lower than in the placebo group. At reevaluation, mean GI and mean PlI of the test group were both significantly (p < 0.0001) lower than in the placebo group. Mean TNF-α serum level did no longer differ significantly between the groups. CONCLUSIONS: The consumption of L. reuteri lozenges may be a useful adjunct in the control of pregnancy gingivitis.

Stimulation of the nitrate-nitrite-NO-metabolism by repeated lettuce juice consumption decreases gingival inflammation in periodontal recall patients: a randomized, double-blinded, placebo-controlled clinical trial.

AIM: This prospective, parallel group, two-armed, double-blind, placebo-controlled randomized trial evaluated the impact of dietary nitrate consumption on gingival inflammation in periodontal recall patients. MATERIAL AND METHODS: Forty-four (23 test/21 placebo) periodontal recall patients with chronic gingivitis were enrolled. At baseline, gingival index (GI), plaque control record (PCR) and salivary nitrate level (SNL) were recorded, followed by sub- and supragingival debridement. Subsequently, participants were randomly provided with 100 ml bottles of a lettuce juice beverage to be consumed 3× daily over 14 days, containing either a standardized amount of nitrate resulting in an intake of approximately 200 mg nitrate per day (test) or being devoid of nitrate (placebo). RESULTS: At baseline, mean GI, PCR and SNL did not differ significantly between the groups. At day 14, mean GI of the test group was significantly reduced compared to baseline and significantly lower (p = 0.002) than in the placebo group (GI 0.3 versus 0.5). Also, mean SNL in the test group was significantly higher than in the placebo group (54.0 µg/ml versus 27.8 µg/ml; p < 0.035). Mean PCR did not change significantly in both groups. CONCLUSIONS: Dietary nitrate consumption may be a useful adjunct in the control of chronic gingivitis.

Prevalence of periodontitis in individuals with human leukocyte antigens (HLA) A9, B15, A2, and B5.

OBJECTIVE: Human leukocyte antigens (HLA) have been associated with periodontitis. Previous studies revealed HLA-A9 and HLA-B15 as potential susceptibility factors, while HLA-A2 and HLA-B5 might have protective effects. The aim of the study was to verify these associations in a group of HLA-typed blood donors with previously unknown periodontal status. MATERIALS AND METHODS: In four German centers, 140 blood donors with known HLA class I status were enrolled and allocated to the following five groups: HLA-A9 (N = 24), HLA-B15 (N = 20), HLA-A2 (N = 30), HLA-B5 (N = 26), and controls (N = 40). Periodontal examination included the measurement of probing depths (PDs), clinical attachment level (CAL), bleeding on probing (BOP), and community periodontal index of treatment needs (CPITN). RESULTS: Carriers with HLA-A9 and HLA-B15 had higher values of mean PD (P < 0.0001), CAL (P < 0.0001), and BOP (P < 0.002) as well as sites with PD and CAL with ≥4 and ≥6 mm (P < 0.0003), respectively, than controls. Multiple regression analyses revealed HLA-A9, HLA-B15, and smoking as risk indicators for moderate to severe (CPITN 3-4; odds ratio (OR): 66.7, 15.3, and 5.1) and severe (CPITN 4; OR: 6.6, 7.4, and 3.8) periodontitis. HLA-A2 and HLA-B5 did not show any relevant associations. CONCLUSION: The present data support a role of HLA-A9 and HLA-B15 as susceptibility factors for periodontitis, whereas HLA-A2 and HLA-B5 could not be confirmed as resistance factors. CLINICAL RELEVANCE: Both HLA antigens A9 and B15 are potential candidates for periodontal risk assessment.

Genome-wide exploration identifies sex-specific genetic effects of alleles upstream NPY to increase the risk of severe periodontitis in men.

AIM: Periodontitis (PD) is influenced by genetic as well as lifestyle and socio-economic factors. Epidemiological studies show that men are at greater risk of severe forms of PD, suggesting interplay between sex and genetic factors. We aimed to systematically analyse patients with aggressive periodontitis (AgP) for gene-sex interactions. MATERIALS AND METHODS: Three hundred and twenty-nine German AgP cases and 983 controls were genotyped with Affymetrix 500K Arrays and were analysed by logistic regression analysis. The most significant gene-sex interaction was replicated in an independent sample of 382 German/Austrian AgP cases and 489 controls. RESULTS: Ten single-nucleotide polymorphisms (SNPs) in strong linkage disequilibrium (r(2)  > 0.85) upstream the gene neuropeptide Y (NPY) suggested gene-sex interaction (p < 5 × 10(-5) ). SNP rs198712 showed the strongest association in interaction with sex (p = 5.4 × 10(-6) ) with odds ratios in males and females of 1.63 and 0.69 respectively. In the replication, interaction of sex with rs198712 was verified with p = 0.022 (pooled p = 4.03 × 10(-6) ) and similar genetic effects. Analysis of chromatin elements from ENCODE data revealed tissue-specific transcription at the associated non-coding region. CONCLUSION: This study is the first to observe a sexually dimorphic role of alleles at NPY in humans and support previous genome-wide findings of a role of NPY in severe PD.

A large candidate-gene association study suggests genetic variants at IRF5 and PRDM1 to be associated with aggressive periodontitis.

AIM: Epidemiological and clinical studies indicated a relationship of periodontitis with rheumatoid arthritis (RA). We aimed to identify shared genetic susceptibility loci of RA and periodontitis. MATERIALS AND METHODS: Forty-seven risk genes of genome-wide significance of RA and SLE were genotyped in a German case-control sample of aggressive periodontitis (AgP), using Immunochip genotyping arrays (Illumina, 600 cases, 1440 controls) and Affymetrix 500 K Genotyping Arrays (280 cases and 983 controls). Significant associations were replicated in 168 Dutch AgP cases and 679 controls and adjusted for the confounders smoking and sex. RESULTS: Variants at IRF5 and PRDM1 showed association with AgP. Upon covariate adjustment for smoking and sex, the most strongly associated variant at IRF5 was the rare variant rs62481981 (ppooled  = 0.0012, odds ratio [OR] = 3.1, 95% confidence interval [95% CI] = 1.6-6.1; 801 cases, 1476 controls).Within PRDM1 it was rs6923419 (ppooled  = 0.004, OR = 0.7, 95% CI = 0.6-0.9; 833 cases, 1440 controls). The associations lost significance after correction for multiple testing in the replication. Both genes are implicated in beta-interferon signalling and are also genome-wide associated with SLE and inflammatory bowel disease. CONCLUSION: The study gives no definite evidence for a pathogenic genetic link of periodontitis and RA but suggests IRF5 and PRDM1 as shared susceptibility factors.

SLC23A1 polymorphism rs6596473 in the vitamin C transporter SVCT1 is associated with aggressive periodontitis.

AIM: Identification of variants within genes SLC23A1 and SLC23A2 coding for vitamin C transporter proteins associated with aggressive (AgP) and chronic periodontitis (CP). MATERIAL AND METHODS: Employment of three independent case-control samples of AgP (I. 283 cases, 979 controls; II. 417 cases, 1912 controls; III. 164 cases, 357 controls) and one sample of CP (1359 cases, 1296 controls). RESULTS: Stage 1: Among the tested single-nucleotide polymorphisms (SNPs), the rare allele (RA) of rs6596473 in SLC23A1 showed nominal significant association with AgP (p = 0.026, odds ratio [OR] 1.26, and a highly similar minor allele frequency between different control panels. Stage 2: rs6596473 showed no significant association with AgP in the replication with the German and Dutch case-control samples. After pooling the German AgP populations (674 cases, 2891 controls) to significantly increase the statistical power (SP = 0.81), rs6596473 RA showed significant association with AgP prior to and upon adjustment with the covariates smoking and gender with padj  = 0.005, OR = 1.35. Stage 3: RA of rs6596473 showed no significant association with severe CP. CONCLUSION: SNP rs6596473 of SLC23A1 is suggested to be associated with AgP. These results add to previous reports that vitamin C plays a role in the pathogenesis of periodontitis.

On the relationship between gingival biotypes and supracrestal gingival height, crown form and papilla height.

OBJECTIVES: To determine the association between gingival biotypes and supracrestal gingival height (primary aim) and its relation to crown shape and papilla height (secondary aim). MATERIALS AND METHODS: Eighty adult subjects were evaluated in this study. Based on the transparency of a periodontal probe through the buccal gingival margin, 38 subjects comprised the thin biotype group and 42 subjects comprised the thick biotype group, respectively. Three different parameters were clinically assessed: supracrestal gingival height (SGH) by bone sounding, crown width/crown length ratio and papilla height. RESULTS: No statistical difference (P > 0.05) was detected neither for the correlation between different biotypes (thick/thin) and SGH nor for the association of biotypes and crown width/crown length ratio. Papilla height was only significantly increased (P ≤ 0.05) in the area of teeth no. 21/22 for the thin periodontal biotype. Intra-examiner deviation was found to be very low for all clinical parameters (percentile agreement > 95%). CONCLUSIONS: Within the limits of this study, we found that in young Caucasians (i) soft tissue dimensions seem to be similar between biotypes (ii) and the traditional hypothesis that a thick gingiva merges with broad-short crown shape and flat papillae and a thin gingiva with a narrow-long crown shape and high scalloping, may be questionable.

Early wound healing and patient morbidity after single-incision vs. trap-door graft harvesting from the palate--a clinical study.

OBJECTIVES: The aim of this study is to compare wound healing and patient pain perception of single-incision (single-incision, modified single-incision) and trap-door surgical techniques to harvest subepithelial connective tissue grafts from the palate. MATERIAL AND METHODS: Thirty-six patients were selected for root coverage procedures with subepithelial connective tissue grafts and randomly assigned to two single-incision groups or a trap-door group (n = 12/group). One week after surgery, a modified early-wound healing index (EHI), patient pain and painkiller intake were recorded. Follow-up was performed until complete epithelialization was achieved. RESULTS: Single-incision techniques showed significantly improved early healing over trap-door approaches. Specifically, the mean EHI was 2.50 ± 1.14 for single-incision techniques, as compared to 3.33 ± 1.30 for trap door. The incidence of secondary healing was significantly lower in the single-incision groups. Concomitantly, the cumulative dosage and duration of painkiller intake were significantly reduced, as compared to the trap-door group. CONCLUSION: Within the limits of this trial, single-incision techniques can lead to improved early healing and reduced patient pain after subepithelial connective tissue graft harvesting than trap-door techniques. CLINICAL RELEVANCE: Avoiding trap-door incisions for harvesting of connective tissue grafts may reduce patient morbidity.