The role of acquired host immunity in periodontal diseases.

The aim of this narrative review is to relate the contribution of European researchers to the complex topic of the host immune system in periodontal disease, focusing on acquired immunity. Other chapters in this volume will address the genetics and autoantibody responses and other forms of immunity to periodontal disease. While the contribution of European authors is the focus, global literature is included in this descriptive narrative for contextual clarity, albeit many with European co-authors. The topic is relatively intense and is thus broken down into sections outlined below, tackled as descriptive narratives to enhance understanding. Any attempt at a systematic or scoping review was quickly abandoned given the descriptive nature and marked variation of approach in almost all publications. Even the most uniform area of this acquired periodontal immunology literature, antibody responses to putative pathogens in periodontal diseases, falls short of common structures and common primary outcome variables one would need and expect in clinical studies, where randomized controlled clinical trials (RCTs) abound. Addressing 'the host's role' in immunity immediately requires a discussion of host susceptibility, which necessitates consideration of genetic studies (covered elsewhere in the volume and superficially covered here).

Expression of Toll-like receptor and cytokine mRNAs in feline odontoclastic resorptive lesion (FORL) and feline oral health.

Feline odontoclastic resorptive lesion (FORL) is a common chronic inflammatory condition whose aetiopathogenesis remains unclear. FORL affects 20-75% of cats and causes excruciating pain and tooth loss. The purpose of this study was to evaluate chronic inflammation in FORL by assessing differences in Toll-like receptor (TLR) and cytokine transcripts in gingival tissues between diseased and healthy cats. Gingival tissue samples were collected from 14 healthy cats with no known clinical signs of oral disease and 41 cats with FORL. Levels of mRNA encoding TLR2, TLR3, TLR4, TLR7, TLR9 and the cytokines interleukin-1ß (IL-1ß), IL-4, IL-6, IL-10, IL-12, interferon-γ (IFN-γ) and tumour necrosis factor-α (TNF-α) was evaluated using quantitative real-time PCR. Statistical significance of the results was assessed using non-parametric tests. Levels of TLR and cytokine transcripts were upregulated in gingival tissue from cats with FORL as compared with healthy gingival tissue: TLR2, TLR3 and TLR9, p ≤ 0.001; TLR4 and TLR7, p ≤ 0.01; IFN-γ, IL-4, IL-6, IL-10, IL-12, IL-1ß and TNF-α, p ≤ 0.001). In conclusion, expression of TLR and both pro- and anti-inflammatory cytokines were significantly increased, confirming an ongoing chronic inflammatory response to the microbiome in FORL. It is likely that dysbiosis of the oral microbiota in cats with FORL activates the innate immune response, leading to active inflammation that results in tooth resorption.

Microbiome analysis of feline odontoclastic resorptive lesion (FORL) and feline oral health.

Introduction. Feline odontoclastic resorptive lesion (FORL) is one of the most common and painful oral diseases of the cat. It is characterised by tooth resorption due to destructive activity of odontoclasts. FORL can result in tooth loss. While the aetiology of FORL is not clearly understood, it is thought to be multifactorial and bacteria are likely to play a major role.Hypothesis. Dysbiosis of the normal feline oral microbiota leads to an alteration in commensal bacteria populations, which results in the development of FORL.Aim. The purpose of the current study was to determine the composition of the microbiomes associated with feline oral health and FORL.Methodology. Supragingival plaque was collected from 25 cats with a healthy oral cavity and 40 cats with FORL. DNA was extracted from each sample, the V4 region of the 16S rRNA gene amplified by polymerase chain reaction and amplicons sequenced. Diversity and species richness analyses were performed, principal component analysis was used to explore differences between the oral microbiomes of healthy cats and those with FORL, and linear discriminant analysis effect size was used to assess differences between the groups.Results. The six most abundant bacterial genera identified were Bergeyella, Capnocytophaga, Lampropedia, Morexella, Porphyromonas and Treponema. Two-step cluster analysis of the data identified two FORL sub-groups (FORL-1, FORL-2). The FORL-2 sub-group was very similar to the healthy group, whilst the FORL-1 sub-group was clearly different from both the FORL-2 sub-group and the healthy groups. In this analysis, Capnocytophaga (P <0.001) and Lampropedia (P <0.01) were found at significantly lower levels and Porphyromonas at a slightly higher level in the FORL-1 sub-group compared to the healthy and FORL-2 sub-groups. Microbial diversity was found to be less in the FORL-1 sub-group than in the healthy group. Lampropedia sp., a phosphate-accumulating oral commensal species, was significantly lower in the FORL-1 sub-group.Conclusion. The oral microbiota associated with the FORL-1 sub-group is distinct from that found in the healthy group and FORL-2 sub-group. Lampropedia species may influence the local calcium-phosphate ratio, which could be a factor in tooth and bone resorption observed in FORL.

Effects of smoking on non-surgical periodontal therapy in patients with periodontitis Stage III or IV, and Grade C.

BACKGROUND: To evaluate possible effects of smoking on clinical, biochemical, and microbiological outcomes of non-surgical periodontal treatment in patients with periodontitis Stage III or IV and Grade C. METHODS: Conventional quadrant-wise non-surgical periodontal treatment was performed and whole-mouth periodontal measurements were recorded at baseline, 1, 3, and 6 months after completion of treatment. Saliva, gingival crevicular fluid, subgingival plaque, and blood samples were obtained at the same time points. Inflammatory cytokine levels, presence, and quantities of 11 different bacterial species were determined. Smoking status was validated by cotinine assay. RESULTS: Fourteen smoker and 13 non-smoker patients completed the study protocol and revealed similar clinical findings except for the higher plaque scores in the non-smokers at 6 months (P <0.01). Significant differences were found between the study groups in biofluid cytokine levels at 1 and 3 months (P <0.01). Gram-negative bacteria were more abundant in the smokers at baseline and so were Gram-positive bacteria in the non-smokers (P <0.01). Gram-negative bacteria repopulated in the smokers faster than in the non-smokers (P <0.01). CONCLUSIONS: The present findings suggest that smoker patients with periodontitis Stage III and IV, Grade C respond well to the non-surgical periodontal treatment during the 6-month follow-up. However, smokers exhibit faster repopulation of Gram-negative bacteria.

Do Adhesive Flash-free Brackets Affect Bacterial Plaque in Patients with Adequate Oral Hygiene? A Randomised Controlled Clinical and Microbiological Assessment.

PURPOSE: To compare adhesive flash-free (FF) and adhesive pre-coated (APC) brackets in terms of plaque retention and constituents, gingival biomarkers and enamel demineralisation. MATERIALS AND METHODS: Fifty adolescents (mean age ± SD; 14.23 ± 0.15 years, age range: 13-18 years) were randomly distributed to receive FF or APC ceramic brackets in the maxillary right or left quadrant. Plaque and gingival indices, quantitative light-induced fluorescence (QLF) imaging, gingival crevicular fluid (GCF) and plaque sampling were performed at baseline and at 1, 2 and 3 months (T0, T1, T2, T3) after bracket placement. QLF was repeated following debonding. GCF samples were analysed for biomarkers by immunoassay and plaque by real-time PCR for bacterial content. Data were analysed using the Wilcoxon test on dependent samples and 2-tailed ANOVA. RESULTS: Plaque index, gingival index and fluorescence changes were similar for the two adhesive-bracket systems. GCF volumes and interleukin (IL)-1ß levels increased compared to baseline (p < 0.05). IL-17A levels and RANKL:OPG ratios were similar in both groups. In dental plaque, Aggregatibacter actinomycetemcomitans numbers were higher in the APC group at T3. Fusobacterium nucleatum (Fn) counts statistically significantly decreased at T1 and T3 as compared to T0 in the FF group (p < 0.05 and p < 0.01, respectively), whereas Fn counts increased in the APC group at T3 (p < 0.01). Porphyromonas gingivalis, Streptococcus oralis and total bacterial counts were significantly higher in the APC group than in the FF group at T3 (p < 0.01). CONCLUSION: In orthodontic patients with good oral hygiene, the quantity of plaque on adhesive flash-free brackets and conventional brackets did not differ, but the constituents of plaque differed, with less pathogenic bacteria detected around adhesive flash-free brackets. Further studies also including a group of individuals with poor oral hygiene and longer follow-up periods may better clarify the issue.

Cholinergic signalling mechanisms and early implant healing phases in healthy versus generalized aggressive periodontitis patients: A prospective, case-control study.

AIMS: Periodontal diseases negatively affect implant osseointegration. Perturbations in non-neuronal cholinergic signalling mechanisms are associated with periodontitis; however, their role in generalized aggressive periodontitis (GAgP) is unknown. The aim of this prospective case-control study was to determine the relationship between non-neuronal cholinergic signalling mechanisms, secreted Ly-6/uPAR-related protein-1 (SLURP-1), interleukin-17 (IL-17) family cytokines and healing of dental implants in health and GAgP. MATERIAL AND METHODS: Thirteen GAgP patients and seven periodontally healthy individuals (PH) were recruited. Peri-implant crevicular fluid (PICF) was obtained at baseline and 1 month post-placement. Acetylcholine (ACh) levels and cholinesterase activity were determined biochemically. SLURP-1, IL-17A and IL-17E levels were determined by ELISA. Marginal bone loss (MBL) at 1 and 6 months post-placement was determined radiographically. RESULTS: The concentration of ACh, cholinesterase activity and IL-17A levels was elevated in PICF of patients with GAgP compared to PH individuals at baseline and 1 month post-placement. The concentration of ACh and cholinesterase activity levels in PICF correlated with levels of IL-17A and MBL around implants 1 month post-placement in patients with GAgP. CONCLUSIONS: Non-neuronal cholinergic mechanisms may play a role in the aetiopathogenesis of GAgP and may directly or indirectly, through modulation of IL-17A, influence early implant osseointegration and potential long-term implant survival.

Plaque Accumulation and Inflammation Adjacent to Restorations of Amorphous Calcium Phosphate-containing Composite in Early Childhood Caries.

PURPOSE: To evaluate the clinical, biochemical, and microbiological reactions to nanocomposite containing amorphous calcium phosphate (ACP) in comparison to a traditional composite restorative material in early childhood caries. MATERIALS AND METHODS: Eighteen teeth were restored with the test material (ACP-containing resin) and 18 teeth were restored with the control material (traditional composite, TC) in fourteen paediatric patients using a split-mouth design. One caries- and restoration-free intact tooth in each patient was selected as the healthy control. Gingival crevicular fluid (GCF) and supragingival plaque samples were collected at baseline before the treatment and also on days 1, 7, 14 and 30 after treatment. Unstimulated whole saliva samples were obtained from each patient at baseline, and 1 and 6 months after restoration. GCF and saliva samples were assayed for IL-17A, IL-17F IL-17A/F, IL-17E, OPG and RANKL levels by ELISA, and plaque composition was assessed using RT-PCR. RESULTS: Clinical evaluation indicated no statistically significant differences between the two restorative materials according to the FDI criteria surface lustre, material retention and marginal adaptation properties. Pro-inflammatory IL-17 levels decreased statistically significantly at 6 months compared to baseline and 1-month values (p < 0.05). The baseline pro-inflammatory IL-17 cytokine levels in GCF samples around the carious teeth were higher than those obtained around the healthy teeth (p < 0.05), but similar in GCF from the ACP-test and TC teeth. Microbiological findings were similar in the ACP and T groups. CONCLUSION: It may be suggested that both ACP-containing and traditional resin composites show similar antimicrobial and biochemical effects in early childhood caries.

Evaluating Streptococcus mutans Strain Dependent Characteristics in a Polymicrobial Biofilm Community.

Aim: The purpose of this study was to investigate strain dependent differences of the cariogenic biofilm forming Streptococcus mutans within both simple and complex communities. Methods: A mono-species containing representative S. mutans clinical isolates (caries and non-caries), and a multispecies in vitro caries biofilm model containing Lactobacillus casei, Veillonella dispar, Fusobacterium nucleatum and Actinomyces naeslundii, and either of two representative S. mutans clinical isolates (caries and non-caries), was developed as a comparison model. Compositional analysis of total and live bacteria within biofilms, and transcriptional analysis of biofilm associated virulence factors were evaluated by live/dead PCR and quantitative PCR, respectively. Scanning electron microscopy (SEM) was used to analyze the architecture of biofilm. One-way analysis of variance and t-tests were used to investigate significant differences between independent groups of data. Results: Within a mono-species biofilm, different S. mutans strains responded similarly to one another during biofilm formation in different carbohydrate sources, with sucrose showing the highest levels of biofilm biomass and galactose showing the lowest. Within the polymicrobial biofilm system, compositional analysis of the bacteria within the biofilm showed that S. mutans derived from a caries-free patient was preferentially composed of both total and viable L. casei, whereas S. mutans derived from a caries patient was dominated by both total and viable S. mutans (p < 0.001). Normalized gene expression analysis of srtA, gtfB, ftf, spaP, gbpB, and luxS, showed a general upregulation within the S. mutans dominant biofilm. Conclusion: We were able to demonstrate that individual strains derived from different patients exhibited altered biofilm characteristics, which were not obvious within a simple mono-species biofilm model. Influencing the environmental conditions changed the composition and functionality S. mutans within the polymicrobial biofilm. The biofilm model described herein provides a novel and reproducible method of assessing the impact on the biofilm microbiome upon different environmental influences.

Clinical associations between acetylcholine levels and cholinesterase activity in saliva and gingival crevicular fluid and periodontal diseases.

AIM: The oral mucosa possesses a non-neuronal cholinergic system. This study aimed to determine clinical evidence for a role of cholinergic mechanisms in the pathogenesis of periodontal diseases. MATERIALS AND METHODS: Fifty healthy participants, 52 patients with gingivitis and 49 with periodontitis were recruited. Full periodontal parameters were recorded and saliva and gingival crevicular fluid (GCF) collected. Levels of acetylcholine and inflammatory mediators were quantified using commercially available assay kits. Acetylcholinesterase and butyrylcholinesterase activities were measured using a published biochemical assay. RESULTS: Acetylcholine levels are significantly elevated in saliva and GCF, whereas GCF levels of butyrylcholinesterase activity are significantly decreased, in patients with periodontal diseases. Acetylcholine levels in saliva and GCF correlated positively with clinical markers of disease severity and with increased levels of IL-17A and IL-17F. In contrast, butyrylcholinesterase activity levels in GCF showed significant negative correlations with clinical markers of disease severity and IL-17A and IL-17F levels. None of the findings were due to smoking. CONCLUSIONS: Elevated acetylcholine levels and reduced butyrylcholinesterase activity are clinically associated with periodontal diseases and elevated levels of IL-17A and IL-17F. Therefore, non-neuronal cholinergic mechanisms may influence IL-17 biology and the aetiopathogenesis of periodontal diseases and therefore are possible therapeutic targets.

Evaluation of tissue levels of Toll-like receptors and cytokine mRNAs associated with bovine periodontitis and oral health.

Bovine periodontitis is a progressive and purulent infection associated with an anaerobic subgingival biofilm, which induces irreversible damage to the dentition of affected animals. The aetiopathogenesis of the disease is unclear and treatment and control of the disease process in cattle are almost unknown. The aim of this study was to investigate the innate immune response by quantifying expression of Toll-like receptor (TLR) and cytokine genes in gingival tissue samples from cattle with and without periodontitis. Postmortem biopsies of gingival tissues were collected from 20 cattle with periodontitis and 20 cattle with no clinical signs of periodontal lesions. Tissue expression of TLR2, TLR4, TNF-α, IFN-γ, IL-1ß and IL-4 genes were determined using quantitative real-time PCR. Statistically significant increases in mRNA levels encoding TLR2 (p = 0.025), TLR4 (p = 0.037), TNF-α (p = 0.025), IFN-γ (p = 0.014), IL-1ß (p < 0.001) and IL-4 (p = 0.014) were observed in animals with periodontitis when compared to periodontally healthy animals. Increased levels of TLRs and inflammatory cytokines in periodontal tissue indicate an induction of the innate immune response of cattle and suggest that a substantial microbial challenge may be involved in the aetiopathogenesis of bovine periodontitis.

Microbiomes associated with bovine periodontitis and oral health.

Periodontitis is an infectious polymicrobial, immuno-inflammatory disease of multifactorial aetiology that has an impact on the health, production and welfare of ruminants. The objective of the present study was to determine the microbial profiles present in the gingival sulcus of cattle considered periodontally healthy and in the periodontal pocket of animals with periodontitis lesions using high-throughput bacterial 16S rRNA gene sequencing. Subgingival biofilm samples were collected from 40 cattle with periodontitis and 38 periodontally healthy animals. In total, 1923 OTUs were identified and classified into 395 genera or higher taxa. Microbial profiles in health differed significantly from periodontitis in their composition (p < 0.0001, F = 5.30; PERMANOVA) but no statistically significant differences were observed in the diversity of healthy and periodontitis microbiomes. The most prevalent taxa in health were Pseudomonas, Burkholderia and Actinobacteria, whereas in disease these were Prevotella, Fusobacterium and Porphyromonas. The most discriminative taxa in health were Gastranaerophilales, Planifilum and Burkholderia, and in disease these were Elusimicrobia, Synergistes and Propionivibrio. In conclusion, statistically significant difference exists between the microbiome in bovine oral health and periodontitis, with populations showing 72.6% dissimilarity. The diversity of the bacteria found in health and periodontitis were similar and bacteria recognised as periodontal pathogens showed increased abundance in disease. In this context, the main components of bacterial homeostasis in the biofilm of healthy sites and of dysbiosis in periodontal lesions provide unprecedented indicators for the evolution of knowledge about bovine periodontitis.

Intraoral versus extraoral cementation of implant-supported single crowns: Clinical, biomarker, and microbiological comparisons.

OBJECTIVES: Implant supported single metal-ceramic crowns cemented either extraorally or intraorally were comparatively evaluated by clinical, radiologic, biomarker, and microbiological parameters. MATERIALS AND METHODS: Twelve patients with bilateral single tooth gap in the maxillary posterior region received two locking-taper implants; 4.5 mm width, 8 mm length. Selection of intraoral (IOC) or extraoral cementation (EOC) using screwless titanium abutments was done randomly. Peri-implant crevicular fluid (PICF), gingival crevicular fluid (GCF) samples were collected from the implants, adjacent teeth, and bleeding on probing, soft tissue thickness, keratinized tissue width were recorded before starting the prosthetic procedures (baseline) and 3, 6 months after implant loading. Crestal bone loss was measured on radiographs taken immediately and 6 months after cementation. Cytokine levels, amounts of bacteria were determined in PICF/GCF samples. Data were tested by appropriate statistical analyses. RESULTS: Clinical findings were similar in the crowns cemented extraorally or intraorally at all times (P < .05). PICF and GCF data were similar. At 3 month, interleukin-17E and osteoprotegerin levels were lower in the intraorally cemented crowns. CONCLUSION: Extraorally and intraorally cemented crowns exhibited similar crestal bone loss after loading. Higher amount of osteoprotegerin at 3 month at the EOC than the IOC sites might bode well for good osseointegration.

Microbiome of peri-implantitis affected and healthy dental sites in patients with a history of chronic periodontitis.

OBJECTIVE: To determine the composition of the microbiome of peri-implantitis sites and corresponding dental sites in subjects with a history of chronic periodontitis. DESIGN: Clinical and radiographic examination assessed the periodontal/peri-implant disease status. Plaque samples were collected from one diseased implant with peri-implantitis, functional for at least two years and healthy sites in ten non-smokers who had received periodontal treatment prior to implant placement. Following DNA extraction, the bacteria present in each sample were determined by high-throughput sequencing of V3-V4 region of the 16S rRNA gene using the Illumina MiSeq platform. OTUs were picked using QIIME. Differences between dental and implant sites were determined using linear discriminant analysis, effect size and diversity analyses were conducted using PAST v3.02. RESULTS: The microbiomes of healthy samples were more diverse than those found in disease, although disease was associated with a higher abundance of taxa relative to health. The genera Actinobacillus and Streptococcus were most closely associated with health, whereas Prevotella and Porphyromonas were most discriminative for disease. Synergistetes were highly associated with peri-implantitis. CONCLUSION: In patients with a history of periodontitis, putative periodontal pathogens prevailed in the microbiome of diseased implants. Diseased implants and corresponding healthy sites appear to have distinct microbiological ecosystems.

The Anti-Adhesive Effect of Curcumin on Candida albicans Biofilms on Denture Materials.

The use of natural compounds as an alternative source of antimicrobials has become a necessity given the growing concern over global antimicrobial resistance. Polyphenols, found in various edible plants, offers one potential solution to this. We aimed to investigate the possibility of using curcumin within the context of oral health as a way of inhibiting and preventing the harmful development of Candida albicans biofilms. We undertook a series of adsorption experiments with varying concentrations of curcumin, showing that 50 µg/ml could prevent adhesion. This effect could be further synergized by the curcumin pre-treatment of yeast cells to obtain significantly greater inhibition (>90%, p < 0.001). Investigation of the biological impact of curcumin showed that it preferentially affected immature morphological forms (yeast and germlings), and actively promoted aggregation of the cells. Transcriptional analyses showed that key adhesins were down-regulated (ALS1 and ALS3), whereas aggregation related genes (ALS5 and AAF1) were up-regulated. Collectively, these data demonstrated that curcumin elicits anti-adhesive effects and that induces transcription of genes integrally involved in the processes related to biofilm formation. Curcumin and associated polyphenols therefore have the capacity to be developed for use in oral healthcare to augment existing preventative strategies for candidal biofilms on the denture surface.

Biomarkers and Bacteria Around Implants and Natural Teeth in the Same Individuals.

BACKGROUND: This cross-sectional study assesses cytokine levels in peri-implant crevicular fluid (PICF)/gingival crevicular fluid (GCF) and a selection of subgingival/submucosal plaque bacteria from clinically healthy or diseased sites in the same individuals. METHODS: Samples from 97 implants/teeth (58 implants [19 healthy, 20 mucositis, 19 peri-implantitis] and 39 natural teeth [19 healthy, 12 gingivitis, eight periodontitis] in 15 systemically healthy patients were investigated by immunoassay and real-time polymerase chain reaction. Samples were obtained first, with probing depth, clinical attachment level, bleeding on probing, plaque index scores, and keratinized tissue width then recorded. Data were analyzed by Wilcoxon, Mann-Whitney U, and permutation tests on dependent, independent, and mixed dependent and independent samples and Spearman correlation. RESULTS: Interleukin (IL)-1ß levels were significantly higher in PICF samples of healthy implants than in GCF samples of healthy teeth (P = 0.003), and soluble receptor activator of nuclear factor-κB ligand (sRANKL) concentrations were significantly higher in the gingivitis than the mucositis group (P = 0.004). Biomarker levels were similar in peri-implantitis and periodontitis groups (P >0.05). Actinomyces naeslundi and Streptococcus oralis levels were significantly higher in the healthy implant group than in healthy teeth (P <0.05). Prevotella intermedia and Treponema denticola (Td) levels were lower in the mucositis group than the gingivitis group (P <0.05). Prevotella oralis and S. oralis levels were significantly higher in the periodontitis group (P <0.05), and Td levels were significantly higher in the peri-implantitis group (P <0.05). CONCLUSION: There were many similarities but, crucially, some differences in biomarker levels (IL-1ß and sRANKL) and bacterial species between peri-implant and periodontal sites in the same individuals, suggesting similar pathogenic mechanisms.

Prevalence of feline calicivirus in cats with odontoclastic resorptive lesions and chronic gingivostomatitis.

Feline odontoclastic resorptive lesion (FORL) and feline chronic gingivostomatitis (FCGS) are two of the most common diseases of the feline oral cavity. While evidence is emerging that FCGS is caused by gingival inflammation initiated and perpetuated by the oral microbiota, little is known in this regard for FORL. Feline calicivirus (FCV) has been associated with the presence of FCGS and is thought to play a role in the initiation of this disease. In this study, the incidence of FCV was investigated in cats with FORL and FCGS, and compared to unaffected controls. FCV was detected by viral culture. The incidence of FCV was as follows: 6 (24.0%) of 24 control cats, 9 (22.5%) of 40 cats with FORL and 15 (60.0%) of 25 cats with FCGS were positive for FCV. There was a significant difference in FCV incidence between all the groups (p=0.003) but none between the control group and the FORL group. However, significant differences were observed in the incidence of FCV between control and FCGS (p=0.010) and between FORL and FCGS (p=0.006). It is concluded that although FCV may be associated with FCGS, it appears unlikely to play a role in FORL.

The application of phenotypic microarray analysis to anti-fungal drug development.

Candida albicans metabolic activity in the presence and absence of acetylcholine was measured using phenotypic microarray analysis. Acetylcholine inhibited C. albicans biofilm formation by slowing metabolism independent of biofilm forming capabilities. Phenotypic microarray analysis can therefore be used for screening compound libraries for novel anti-fungal drugs and measuring antifungal resistance.

Candida albicans biofilm heterogeneity does not influence denture stomatitis but strongly influences denture cleansing capacity.

Approximately 20 % of the UK population wear some form of denture prosthesis, resulting in denture stomatitis in half of these individuals. Candida albicans is primarily attributed as the causative agent, due to its biofilm -forming ability. Recently, there has been increasing evidence of C. albicans biofilm heterogeneity and the negative impact it can have clinically; however, this phenomenon has yet to be studied in relation to denture isolates. The aims of this study were to evaluate C. albicans biofilm formation of clinical denture isolates in a denture environment and to assess antimicrobial activity of common denture cleansers against these tenacious communities. C. albicans isolated from dentures of healthy and diseased individuals was quantified using real-time PCR and biofilm biomass assessed using crystal violet. Biofilm development on the denture substratum poly(methyl methacrylate), Molloplast B and Ufi-gel was determined. Biofilm formation was assessed using metabolic and biomass stains, following treatment with denture hygiene products. Although C. albicans was detected in greater quantities in diseased individuals, it was not associated with increased biofilm biomass. Denture substrata were shown to influence biofilm biomass, with poly(methyl methacrylate) providing the most suitable environment for C. albicans to reside. Of all denture hygiene products tested, Milton had the most effective antimicrobial activity, reducing biofilm biomass and viability the greatest. Overall, our results highlight the complex nature of denture- related disease, and disease development cannot always be attributed to a sole cause. It is the distinct combination of various factors that ultimately determines the pathogenic outcome.

Effect of gingival inflammation on the inflammatory response in patients with idiopathic uveitis.

OBJECTIVES: This study aimed to investigate the levels of 11 oral species in plaque samples and cytokine levels in biofluid samples of patients with idiopathic uveitis (IU) and systemically healthy individuals (H) with or without gingival inflammation. MATERIAL & METHODS: Twenty-one patients with IU (n = 21), and 22 systemically healthy individuals (n = 22) were enrolled in the study. Clinical periodontal measurements were recorded. Cytokine levels in the biofluid samples were determined by ELISA. Bacterial gene copy numbers were determined by qPCR on plaque microbial DNA preparations. RESULTS: According to two-step cluster analysis, anova and t-test: GCF, serum and salivary TNF-α, IL-17A, IL-17A/E; GCF and serum IL-6; salivary IL-17F, and salivary and serum IL-17A/F levels were higher in the IU group than the H group (p < 0.05). However, serum IL-10 and IL-17E levels were higher in the H group than the IU group (p < 0.05). A. actinomycetemcomitans, F. nucleatum, S. oralis, A. naeslundii, and V. dispar counts were higher in IU group compared to H group (p < 0.05). CONCLUSION: Altered local and systemic cytokine profiles are associated with differences in the microbial plaque composition in IU. Anti-inflammatory cytokines; IL-10, IL-17E are reduced in patients with IU and Th-1 and Th-17 driven inflammatory responses in biofluids are altered.