Distinctive genes and signaling pathways associated with type 2 diabetes-related periodontitis: Preliminary study.

The biological mechanisms underlying the pathogenesis of type 2 diabetes (T2DM)-related periodontitis remain unclear. This cross-sectional study evaluated the distinctive transcriptomic changes between tissues with periodontal health and with periodontitis in patients with T2DM. In this cross-sectional study, whole transcriptome sequencing was performed on gingival biopsies from non-periodontitis and periodontitis tissues from non-diabetic and diabetic patients. A differentially expressed gene (DEG) analysis and Ingenuity Pathway Analysis (IPA) assessed the genes and signaling pathways associated with T2DM-related periodontitis. Immunohistochemistry was performed to validate selected DEGs possibly involved in T2DM-related periodontitis. Four hundred and twenty and one thousand five hundred and sixty-three DEGs (fold change ≥ 2) were uniquely identified in the diseased tissues of non-diabetic and diabetic patients, respectively. The IPA predicted the activation of Phagosome Formation, Cardiac ß-adrenergic, tRNA Splicing, and PI3K/AKT pathways. The IPA also predicted the inhibition of Cholesterol Biosynthesis, Adrenomedullin, and Inositol Phosphate Compounds pathways in T2DM-related periodontitis. Validation of DEGs confirmed changes in protein expression of PTPN2, PTPN13, DHCR24, PIK3R2, CALCRL, IL1RN, IL-6R and ITGA4 in diseased tissues in diabetic subjects. Thus, these preliminary findings indicate that there are specific genes and functional pathways that may be involved in the pathogenesis of T2DM-related periodontitis.

Systemic Antibiotics and Chlorhexidine Associated with Periodontal Therapy: Microbiological Effect on Intraoral Surfaces and Saliva.

The effect of systemic antibiotics on the microbial profile of extracrevicular sites after periodontal treatment is currently the subject of research. This study evaluated the microbiological effects on different oral cavity sites of scaling and root planing (SRP) combined with antimicrobial chemical control in the treatment of periodontitis. Sixty subjects were randomly assigned to receive SRP alone or combined with metronidazole (MTZ) + amoxicillin (AMX) for 14 days, with or without chlorhexidine mouth rinse (CHX) for 60 days. Microbiological samples were evaluated by checkerboard DNA-DNA hybridization until 180 days post therapy. The adjunctive use of antibiotics plus CHX significantly reduced the mean proportions of red complex species from subgingival biofilm and saliva (p < 0.05). Furthermore, the analysis of all intraoral niches showed a significantly lower mean proportion of the red complex species in the same group. In conclusion, the concomitant use of antimicrobial chemical control (systemic and local) demonstrated a beneficial effect on the composition of the oral microbiota.

Lithium chloride stimulates bone formation in extraction socket repair in rats.

PURPOSE: Previous evidence shows that lithium chloride (LiCl), a suppressor of glycogen synthase kinase-3ß (GSK-3ß), may enhance bone formation in several medical and dental conditions. Thus, the purpose of the current study was to assess the effects of LiCl on extraction socket repair in rats. METHODS: Thirty rats were randomly assigned into a control group (administration of water; n = 15) or a LiCl group (administration of 150 mg/kg of LiCl; n = 15). LiCl and water were given every other day, starting at 7 days before the extraction of upper first molars until the end of each experiment period. Histological sections from five rats per group were obtained at 10, 20, and 30 days post-extractions. Histometrical analysis of newly formed bone (NB) and the levels of tartrate-resistant acid phosphatase (TRAP)-stained cells were evaluated at 10, 20, and 30 days post-extractions. Immunohistochemical staining for receptor activator of nuclear factor kappa-Β ligand (RANKL), osteoprotegerin (OPG), bone sialoprotein (BSP), osteocalcin (OCN), and osteopontin (OPN) was assessed at 10 days post-extractions. RESULTS: The LiCl group had a greater proportion of NB than the control group at 20 days (P < 0.05). At 30 days, the rate of TRAP-stained cells was lower in the LiCl group than in the control group (P < 0.05). At 10 days, the LiCl group presented stronger staining for OPG, BSP, OPN, and OCN, when compared to the control group (P < 0.05). CONCLUSION: Systemic LiCl enhanced extraction socket repair, stimulated an overall increase in bone formation markers, and restricted the levels of TRAP in rats.

Recent Updates on Microbial Biofilms in Periodontitis: An Analysis of In Vitro Biofilm Models.

The development of oral biofilm models has been extremely important to study the specific role of most microbial species at the early stages of periodontitis. The current knowledge on monospecies or multispecies biofilms originates mainly from the observation of in vitro dynamic or static biofilm model systems, which were engineered to mimic clinical oral conditions. In the last few decades, mounting evidence has confirmed that biofilms are the major form of bacterial lifestyle, and more importantly, that microorganisms dwelling in sessile mixed-species aggregates display completely different phenotypes and physiological characteristics than when living in planktonic pure cultures. Interspecies interactions within these communities, mediated by chemical communication systems, have been shown to affect biofilm physiology and increase antimicrobial resistance by up to 1000 fold. These aspects reinforce the importance of developing multispecies biofilm models to better understand and control biofilms. Literature reports demonstrate that while monospecies models are still most commonly used in caries research, authors have used different multispecies models to study periodontal diseases. Periodontitis is a polymicrobial biofilm-dependent disease mainly associated with Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola. Interestingly, these species hardly adhere to substrates commonly used for biofilm formation, which makes multispecies models essential for an accurate analysis of periodontitis-related biofilms. The multispecies models currently available are generally composed of 6-10 species, but a more recent 34-species model was developed to better examine the dynamics within oral biofilms. The complexity of such polymicrobial biofilm models mimics more consistently the oral microbiome and different aspects of the oral environment. Collectively, the evidence on multispecies biofilm models described herein may support future studies on the use of antimicrobials for biofilm control as well as provide research opportunities to expand the current knowledge on interspecies interactions. The present manuscript reviews the most recent updates on in vitro biofilm model systems for periodontitis.

Impact of Smoking Cessation on Periodontal Tissues.

There is cumulative evidence supporting the negative effects of smoking on periodontal tissues. Smoking cessation can be successfully accomplished through specific programs, including behaviour modification and medications, and has been suggested as a suitable way to reduce the risk of several diseases, including periodontitis. The aim of this review is to provide a concise overview of the current knowledge about the impact of smoking cessation on periodontal tissues and therapy, with data from studies published in the last 15 years. Literature was searched using Medline database from 2005 up to and including September 2020 using medical subject heading (MeSH) terms and other search terms, restricted to the English language. Studies were evaluated and summarised in a narrative review format. Results demonstrated that there is convincing evidence to support the benefits of tobacco cessation in reducing the risk of periodontitis and tooth loss. In addition, the harmful effects of smoking on periodontal tissues seem to be assuaged as the number of years since quitting increases. The existing current evidence, even limited, also shows that smoking cessation may result in additional benefits to the outcome of nonsurgical periodontal treatment. Periodontal care providers should not only check their patient's smoking habit for estimating risk of disease progression and predictability of periodontal therapy, but they should also help smokers improve their oral and systemic health by providing efficient and personalised tobacco-cessation counselling and treatment.

Metronidazole and amoxicillin for patients with periodontitis and diabetes mellitus: 5-year secondary analysis of a randomized controlled trial.

BACKGROUND: The aim of this study was to perform a 5-year follow-up analysis of a previously-published randomized trial (RCT) evaluating the 2-years effects of metronidazole (MTZ) plus amoxicillin (AMX) as adjuncts to scaling and root planing (SRP) in the treatment of periodontitis in type 2 diabetic patients. METHODS: Volunteers who received periodontal treatment in the aforementioned RCT were selected for clinical and microbiological evaluation. Patients did not receive regular supportive periodontal therapy (SPT) from 2 to 5 years post-treatment. RESULTS: Of the patients enrolled in the RCT, 43% entered this study (n = 10/control and 15/test group). Most of clinical parameter values, including the number of sites with probing depth ≥ 5 mm (primary outcome variable), were reduced at 5 years post-therapy when compared with baseline in the antibiotic-treated group (P < 0.05), but presented higher values than those at 2 years (P < 0.05). The mean proportions of microbial complexes did not differ between MTZ+AMX+SRP and SRP-only groups at 5 years post-treatment (P > 0.05). CONCLUSION: Diabetic patients treated with adjunctive MTZ+AMX were better maintained over a period of 5 years than those treated with SRP only. However, the clinical and microbiological benefits obtained up to 2 years post-treatment were not fully sustained in these patients who did not receive SPT between 2 and 5 years post-treatment.

Levels of Gene Expression of Immunological Biomarkers in Peri-Implant and Periodontal Tissues.

This study compared the gene expression of the immunoinflammatory markers interleukin (IL)-6, IL-1ß, and tumor necrosis factor alpha (TNF-α), the matrix metalloproteinases (MMP)-1, -2, -8, and -9, and the tissue inhibitors of matrix metalloproteases (TIMP)-1 and -2 in the gingival tissue of individuals with periodontal and peri-implant disease. The study population included individuals with four periodontal statuses: periodontal health (PH group, n = 20); periodontitis (P group, n = 20); peri-implant health (PIH group, n = 20), and peri-implantitis (PI group, n = 20). Gingival biopsies were collected from one tooth per patient according to the inclusion criteria of each group. The mRNA levels of IL-6, IL-1ß, TNF-α, MMP-1, MMP-2, MMP-8, MMP-9, TIMP-1, and TIMP-2 were evaluated by qPCR. The levels of IL-1ß were significantly higher in the PI group when compared to the other groups (p < 0.05), while the levels of IL-6 were significantly higher in the groups with periodontal and peri-implant disease when compared with the healthy groups (p < 0.05); however, the levels of IL-6 did not differ between the PI and P groups (p > 0.05). For all other studied biomarkers, no significant differences were observed between groups (p > 0.05). IL-6 and IL-1ß presented higher levels of mRNA in diseased periodontal and peri-implant tissues. However, the expression of metalloproteinases and their inhibitors did not differ between the different periodontal statuses.

Cytokine profiles of healthy and diseased sites in individuals with periodontitis.

OBJECTIVE: The aims of this study were: 1) to compare the levels of cytokines between healthy and diseased sites, in patients with untreated periodontitis; 2) to correlate cytokine levels with each other and with key periodontal pathogens, in healthy and diseased sites. METHODS: Paired gingival crevicular fluid (GCF) samples were obtained from two healthy (probing depth (PD) and clinical attachment level (CAL) ≤3 mm without bleeding) and two diseased sites (PD and CAL ≥5 mm with bleeding on probing [BoP]) of patients with generalized stage III/IV grade B/C periodontitis. GCF levels of eighteen cytokines and subgingival levels of seven periodontal pathogens were assessed by multiplex immunoassay and qPCR, respectively. RESULTS: A total of 112 subjects and 448 GCF samples were analyzed. The GCF levels of GM-CSF, IL-17, IL-1ß, IL-2, IL-21, IL-23 and TGF-ß were significantly higher in the diseased than in the healthy sites (p < 0.05). Levels of IL-8 and MIP-1α were significantly higher in the healthy than in the diseased sites (p < 0.05). In the healthy sites, IL-8 and MIP-1α formed an independent cluster of cytokines and, MIP-1α positively correlated with Porphyromonas gingivalis (p < 0.05). In deep sites, smoking negatively associated with GM-CSF, IL-10, IL-17, IL-23, IL-5, IL-6, IL-7, IL-8 and MIP-1α levels (p < 0.05). CONCLUSIONS: Diseased sites exhibited increased levels of T helper 17-related cytokines and TGF-ß while healthy sites presented increased levels of the chemokines, IL-8 and MIP-1α. Patients with periodontitis may not only have inflammation in diseased deep sites, but also present significant hidden subclinical inflammation in their shallow clinically healthy sites.

Evaluation of the Microbiological Profile of Alveolar Residual Screws and Cleft-Adjacent Teeth in Individuals With Complete Unilateral Fissures.

OBJECTIVE: To evaluate the microbiota profile of residual alveolar slits and teeth adjacent to the cleft in fissured individuals. DESIGNS: This study used a cross-sectional design. PARTICIPANTS: Twenty individuals, aged 14 to 24 years, who had a residual fissure in the maxillary alveolar ridge region were selected. MAIN OUTCOME MEASURES: Three sites per individual were selected for microbiological collection (the site of the residual cleft and the 2 nearest teeth). The samples were analyzed using the Checkerboard DNA-DNA hybridization technique for 73 species of bacteria. RESULTS: All the species analyzed were found in the 2 niches (slits and teeth). The bacterial species present in the largest number in the residual cracks were Prevotella melaninogenica, Prevotella nigrescens, and Streptococcus mitis. With regard to the bacterial profiles in the mesial and distal faces, the most prevalent species were P nigrescens, Veillonella parvula, and Fusobacterium nucleatum sp vicentii. The analysis of all the collected samples demonstrated very similar profiles for the mesial and distal faces, with these 2 sites even presenting the same species in greater frequencies. Higher counts of 20 bacterial species (Wilcoxon test) were observed in the dental niche, in relation to the fissure, particularly, P nigrescens, V parvula, F nucleatum sp vicentii, and Neisseria mucosa. CONCLUSION: Some species were significantly more prevalent in the residual alveolar fissures and in adjacent teeth. The comparison between the profiles of the 2 niches demonstrated large differences in the most frequent species in the teeth, and no qualitative differences with regard to specific pathogens.

Preliminary findings on the possible role of B-lymphocyte stimulator (BLyS) on diabetes-related periodontitis.

The possible role of B-cell growth and differentiation-related cytokines on the pathogenesis of diabetes-related periodontitis has not been addressed so far. The aim of this study was to evaluate the effects of diabetes mellitus (DM) on the gene expression of proliferation-inducing ligand (APRIL) and B-lymphocyte stimulator (BLyS), two major cytokines associated to survival, differentiation and maturation of B cells in biopsies from gingival tissue with periodontitis. Gingival biopsies were obtained from subjects with periodontitis (n = 17), with periodontitis and DM (n = 19) as well as from periodontally and systemically healthy controls (n = 10). Gene expressions for APRIL, BLyS, RANKL, OPG, TRAP and DC-STAMP were evaluated using qPCR. The expressions APRIL, BLyS, RANKL, OPG, TRAP and DC-STAMP were all higher in both periodontitis groups when compared to the control group (p < 0.05). Furthermore, the expressions of BLyS, TRAP and RANKL were significantly higher in the subjects with periodontitis and DM when compared to those with periodontitis alone (p < 0.05). The mRNA levels of BLyS correlated positively with RANKL in the subjects with periodontitis and DM (p < 0.05). BLyS is overexpressed in periodontitis tissues of subjects with type 2 DM, suggesting a possible role of this cytokine on the pathogenesis DM-related periodontitis.

Strontium ranelate improves alveolar bone healing in estrogen-deficient rats.

BACKGROUND: This study evaluated the impact of strontium ranelate on tooth-extraction wound healing in estrogen-deficient and estrogen-sufficient rats. METHODS: Ninety-six Wistar rats (90 days of age) were allocated into one of the following groups: sham-surgery+water (estrogen-sufficient); ovariectomy+water (estrogen-deficient), sham-surgery+strontium ranelate (625 mg/kg/d) (strontium/estrogen-sufficient); ovariectomy+strontium ranelate (625 mg/kg/d) (strontium/estrogen-deficient). Water or strontium ranelate were administrated from the 14th day post-ovariectomy/sham surgery until euthanasia. Maxillary first molars were extracted at 21 days after sham/ovariectomy surgery. Rats were euthanized at 10, 20, and 30 days post-extractions. The following parameters were analyzed inside tooth-extraction wound: proportion of newly formed bone (bone healing/BH), number of cells stained for tartrate-resistant acid phosphatase (TRAP) and immunohistochemical staining for five bone metabolism-related markers (osteocalcin [OCN], osteopontin [OPN], bone sialoprotein [BSP], osteoprotegerin [OPG] and receptor activator of NF-КB ligand [RANKL]). RESULTS: The estrogen-deficient group presented lower BH than all other groups at 20 and 30 days post-extraction (P < 0.05). The number of TRAP-stained cells was higher in the estrogen-deficient group than in estrogen-sufficient group at 30 days post-extraction (P < 0.05). The strontium /estrogen-sufficient group exhibited stronger staining for OCN, when compared to the estrogen-sufficient and estrogen-deficient groups (P < 0.05). Both strontium ranelate-treated groups presented higher staining of OPN and BSP than both untreated groups (P < 0.05). The strontium/estrogen-sufficient group demonstrated stronger staining for OPG than the estrogen-deficient group (P < 0.05). The estrogen-sufficient group and both groups treated with strontium ranelate showed lower expression of RANKL than the estrogen-deficient group (P < 0.05). CONCLUSIONS: Strontium ranelate benefited BH and the expression of bone markers in tooth-extraction wound in estrogen-deficient rats whereas its benefits in estrogen-sufficient rats were modest.

Effects of strontium ranelate on ligature-induced periodontitis in estrogen-deficient and estrogen-sufficient rats.

BACKGROUND AND OBJECTIVES: Strontium ranelate is a medication indicated for the treatment of osteoporosis that presents concomitant anti-resorptive and osteoanabolic dual biological activity. However, the effects of strontium ranelate on alveolar bone have been poorly explored. Furthermore, to date, there are no data on the effects of this medication on alveolar bone loss (BL) during conditions of estrogen deficiency. Therefore, the aim of this study was to evaluate the effects of strontium ranelate on ligature-induced periodontitis in estrogen-deficient and estrogen-sufficient rats. METHODS: Ninety-six rats were assigned to one of the following groups: sham-surgery + water (estrogen-sufficient; n = 24); ovariectomy + water (estrogen-deficient; n = 24), sham-surgery + strontium ranelate (ranelate/estrogen-sufficient; n = 24) and; ovariectomy + strontium ranelate (ranelate/estrogen-deficient; n = 24). The rats received strontium ranelate or water from the 14th day after ovariectomy until the end of the experiment. On the 21st day after ovariectomy, one first mandibular molar received a ligature, while the contralateral tooth was left unligated. Eight rats per group were killed at 10, 20, and 30 days after ligature placement. Bone loss (BL) and trabecular bone area (TBA) were analyzed in the furcation area of ligated and unligated teeth at all experimental times by histometry. Tartrate-resistant acid phosphatase (TRAP) positive cells and immunohistochemical staining for osteocalcin (OCN), osteopontin (OPN), osteoprotegerin (OPG), and receptor activator of NF-КB ligand (RANKL) were assessed in the ligated teeth at 30 days after ligature placement. RESULTS: At 10 and 30 days, ligated teeth of the estrogen-deficient group exhibited higher BL, when compared to all other groups (P < .05). At 10 days, TBAs were higher in the unligated teeth of strontium ranelate-treated groups, when compared to those of untreated groups (P < .05). At 30 days, the ligated teeth of the estrogen-deficient group exhibited lower TBA than the other groups (P < .05). There were no differences among groups regarding the number of TRAP-stained cells (P < .05). The strontium ranelate-treated groups exhibited lower expressions of OCN and RANKL than the untreated groups (P < .05). The estrogen-sufficient group presented higher staining for OPG than both treated and untreated estrogen-deficient groups (P < .05). CONCLUSIONS: Strontium ranelate prevented ligature-induced BL in an estrogen-deficiency condition and, to a certain extent, increased TBA in the presence and absence of periodontal collapse in states of estrogen deficiency and estrogen sufficiency. Furthermore, strontium ranelate also affected the expression of bone markers, appearing to have acted predominantly as an anti-resorptive agent.

Effects of a full-mouth disinfection protocol on the treatment of type-2 diabetic and non-diabetic subjects with mild-to-moderate periodontitis: one-year clinical outcomes.

OBJECTIVES: This study compared the clinical effects of a full-mouth disinfection (FMD) protocol for the treatment of mild-to-moderate periodontitis in type 2 diabetic and non-diabetic subjects for up to 1 year. Secondary aim was to evaluate the effects of this therapy on the salivary levels of periodontal pathogens between diabetics and non-diabetics. MATERIAL AND METHODS: Twenty-six type 2 diabetic subjects and 28 non-diabetic subjects with mild-to-moderate periodontitis received full-mouth scaling and root planing within 24 h, application of chlorhexidine digluconate (CHX) gel in pockets and tongue plus CHX rinses for 14 days. Clinical monitoring was performed at baseline, 3, 6, and 12 months post-therapy. Salivary levels of red complex bacterial species were evaluated at baseline, 6, and 12 months post-therapy by qPCR. RESULTS: Intention-to-treat analyses were performed for seven diabetics and three non-diabetics that did not return for the 12-month evaluation. Most clinical parameters improved significantly at 3, 6, and 12 months post-therapies for both groups (p < 0.05). Overall, there were no significant differences in clinical parameters between groups after therapy (p > 0.05). At 1 year, 39.3% and 50.0% of the non-diabetic and diabetic subjects, respectively, achieved the desired clinical endpoint for treatment (≤ 4 sites with probing depth ≥ 5 mm) (primary outcome variable) (p > 0.05). FMD did not promote changes in the salivary levels of pathogens in either of the groups (p > 0.05). Levels of T. forsythia were lower in diabetic than in non-diabetic subjects at 6 months post-therapy (p < 0.05). CONCLUSIONS: Type 2 diabetic subjects and systemically healthy subjects with mild-to-moderate periodontitis responded similarly to the proposed FMD protocol for up to 1 year. CLINICAL RELEVANCE: There is a general thought that diabetics do not answer as well as non-diabetics to periodontal treatments. However, this study showed that diabetics and non-diabetics respond equally to the FMD protocol. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02643771.

Lithium chloride assuages bone loss in experimental periodontitis in estrogen-deficient rats.

OBJECTIVES: Evidence shows that lithium, a medication commonly used for bipolar disorder treatment, presents bone anabolic activity. This study evaluated the effects of lithium chloride on periodontitis-induced bone loss (BL) and on intact alveolar bone during estrogen sufficiency and deficiency. MATERIALS AND METHODS: Rats (24/group) received sham surgery plus water (estrogen-sufficient group), ovariectomy plus water (estrogen-deficient group), sham surgery plus lithium chloride (150 mg/kg/every other day) (lithium/estrogen-sufficient group), or ovariectomy plus lithium chloride (lithium/estrogen-deficient group). One first mandibular molar received ligature, while the contralateral molar was left unligated. BL and trabecular bone area (TBA) were assessed in the furcation bone at 10, 20, and 30 days after ligature placement. Histochemical staining for TRAP and immunohistochemical staining for osteocalcin, osteopontin, osteoprotegerin, and RANKL were evaluated at 30 days after ligature placement. RESULTS: At 10 days, the estrogen-deficient group presented the highest BL (0.115 ± 0.026), while the lithium/estrogen-deficient group (0.048 ± 0.024) presented the lowest BL in the ligated teeth (p < 0.05). At 20 and 30 days, the estrogen-deficient group exhibited significantly higher BL than all the other groups (p < 0.05). The ligated teeth of the lithium/estrogen-sufficient group presented the highest TBA while those of the estrogen-deficient group presented the lowest TBA at 10 and 30 days (p < 0.05). Unligated teeth of lithium-treated groups had stronger staining for osteocalcin and osteopontin than the estrogen-deficient group (p < 0.05). Ligated and unligated teeth of the estrogen-deficient group exhibited lower expression of osteoprotegerin than the other groups (p < 0.05). Lithium-treated groups exhibited generally higher staining of RANKL than the untreated groups (p < 0.05). Unligated teeth in both estrogen-sufficient groups presented lower TRAP expression than both estrogen-deficient groups (p < 0.05). CONCLUSIONS: Lithium chloride reduced ligature-induced BL in estrogen-deficient rats and yielded an overall greater trabecular area and overexpression of bone markers in alveolar bone under normal and deficient estrogen states. CLINICAL RELEVANCE: Lithium chloride may be a promising agent to assuage alveolar bone loss related to periodontitis, especially in osteoporotic conditions.

Might smoking assuage the pro-inflammatory effect of diabetes in periodontal sites?

OBJECTIVES: This study evaluated the effects of type 2 diabetes mellitus (DM), smoking, and these two factors combined on gingival crevicular fluid levels and ratios of pro-/anti-inflammatory cytokines. Associations between cytokines with each other and with key periodontal pathogens in periodontal sites under the challenge of one or both of these risk factors were also assessed. METHODS: A total of 102 subjects with periodontitis were included in this cross-sectional study and assigned to one of the following groups: non-diabetic non-smokers (control group, n = 25), non-smokers with DM (DM group, n = 30), non-diabetic smokers (S group, n = 26), and smokers with DM (S + DM group, n = 21). The levels of 13 pro-inflammatory (IFN-γ, TNF-α, MIP-1α, GM-CSF, IL-1ß, IL-2, IL-6, IL-7, IL-8, IL-12, IL-17, IL-21, and IL-23) and 5 anti-inflammatory (IL-4, IL-5, IL-10, IL-13, and TGF-ß) cytokines were assessed in healthy and diseased sites, using multiplex immunoassay. Ratios of pro-/anti-inflammatory cytokines were obtained in all possible permutations. The levels of 7 key periodontal pathogens were evaluated by qPCR. RESULTS: Overall, the ratios of pro-/anti-inflammatory cytokines were higher in healthy and diseased sites of the DM group and in healthy sites of the S + DM group, and lower in diseased sites of the S group, compared with the control (p < .05). The proportion of the pro-inflammatory cytokines in relation to the 18 cytokines studied was higher in the DM group and lower in the S group, whereas the proportion of the anti-inflammatory cytokines was lower in both diabetic groups and higher in the S group, compared to the control (p < .05). A cluster of six common cytokines (IL-4, IL-5, IL-12, IL-13, IL-21, and IL-23) was observed in the diseased sites of all groups studied. Eight common cytokines (IL-4, IL-5, IL-12, IL-13, IL-17, IL-21, IL-23, and IFN-γ) grouped closely in the healthy sites of both diabetic groups. Significant associations between pathogens and cytokines occurred mainly in the diseased sites of the S + DM group (p < .05). CONCLUSION: Diabetes mellitus induced an overall pro-inflammatory state, while smoking mainly stimulated immunosuppression in periodontal sites. When the two risk factors overlapped, smoking seemed to partially assuage the hyperinflammatory effect of DM.

Preliminary findings on the possible role of B-lymphocyte stimulator (BLyS) on diabetes-related periodontitis

Abstract The possible role of B-cell growth and differentiation-related cytokines on the pathogenesis of diabetes-related periodontitis has not been addressed so far. The aim of this study was to evaluate the effects of diabetes mellitus (DM) on the gene expression of proliferation-inducing ligand (APRIL) and B-lymphocyte stimulator (BLyS), two major cytokines associated to survival, differentiation and maturation of B cells in biopsies from gingival tissue with periodontitis. Gingival biopsies were obtained from subjects with periodontitis (n = 17), with periodontitis and DM (n = 19) as well as from periodontally and systemically healthy controls (n = 10). Gene expressions for APRIL, BLyS, RANKL, OPG, TRAP and DC-STAMP were evaluated using qPCR. The expressions APRIL, BLyS, RANKL, OPG, TRAP and DC-STAMP were all higher in both periodontitis groups when compared to the control group (p < 0.05). Furthermore, the expressions of BLyS, TRAP and RANKL were significantly higher in the subjects with periodontitis and DM when compared to those with periodontitis alone (p < 0.05). The mRNA levels of BLyS correlated positively with RANKL in the subjects with periodontitis and DM (p < 0.05). BLyS is overexpressed in periodontitis tissues of subjects with type 2 DM, suggesting a possible role of this cytokine on the pathogenesis DM-related periodontitis.

An umbrella review on the effects of diabetes on implant failure and peri-implant diseases.

The aim of this review is to summarize the evidence on associations between diabetes mellitus (DM) and complications around dental implants. Electronic database searches of MEDLINE, EMBASE, JBI Database of Systematic Reviews and Implementation Reports, Cochrane Database of Systematic Reviews and the PROSPERO register were performed from 1990 up to and including May 2018, using MeSH terms and other keywords. Systematic reviews and meta-analyses investigating the associations of DM and implant complications (failure, survival, bone loss, peri-implant diseases, and post-surgery infection) were eligible. The quality of the included reviews was determined using the Assessment of Multiple Systematic Reviews Tool 2 (AMSTAR 2). Twelve systematic reviews were included. Implant survival rates ranged from 83.5% to 100%, while implant failure rates varied from 0% to 14.3% for subjects with DM. The three meta-analyses performed for event "implant failure" reported no statistically significant differences between diabetic and non-diabetic subjects. An apparently increased risk of peri-implantitis is reported in patients with DM. According to the AMSTAR 2 classification, 50% of the reviews were classified as being of "critically low", 25% as of "low" and 25% as of "moderate" quality. Evidence indicates high levels of survival and low levels of failure of implants inserted in patients with DM. However, DM was assessed as a whole in the majority of studies and, the actual influence of hyperglycemia on implant survival/failure is still uncertain. DM/hyperglycemia seems to be associated with a high risk of peri-implantitis. However, this conclusion is based on a limited number of systematic reviews.

The ratios of pro-inflammatory to anti-inflammatory cytokines in the serum of chronic periodontitis patients with and without type 2 diabetes and/or smoking habit.

OBJECTIVE: This study assessed the impact of chronic periodontitis (CP) and CP associated with type 2 diabetes mellitus (DM) and/or smoking on the serum ratios of pro- to anti-inflammatory cytokines. MATERIALS AND METHODS: Subjects were assigned into one of the following groups: control (n = 25, non-diabetic non-smokers with no history of periodontitis), CP (n = 26, non-diabetic non-smokers with CP), DMCP (n = 30, non-smokers with DM and CP), SCP (n = 27, non-diabetic smokers with CP), and SDMCP (n = 22, smokers with type 2 DM and CP). Serum levels of 18 cytokines were measured using multiplex immunoassays. RESULTS: Six ratios of pro-inflammatory to anti-inflammatory cytokines were significantly higher in the CP group than in the control group (p < 0.05). Eleven, seventeen and nine ratios of pro-inflammatory to anti-inflammatory cytokines were significantly higher in the DMCP, SCP and SDMCP groups than in the control group, respectively (p < 0.05). The SCP group presented higher serum ratios of tumor necrosis factor (TNF)-α/interleukin (IL)-4, TNF-α/IL-5, IL-17/IL-13 and IL-6/IL-13 (p < 0.05) than the CP group. Cluster analysis revealed a relevant cluster composed of ten cytokines (IL-17, IL-23, interferon-γ, IL-12, IL-1ß, IL-2, IL-21, IL-6, IL-4 and granulocyte-macrophage colony-stimulating factor [GM-CSF]) in the serum of subjects from the DMCP group. CONCLUSIONS: The ratios of pro- to anti-inflammatory cytokines shift to favor a pro-inflammatory status in the serum of patients with CP and even more when CP is associated with one or both risk factors. CLINICAL RELEVANCE: CP and CP associated with hyperglycemia and/or smoking might contribute to a systemic inflammatory burden and increased risk of systemic complications.

Protein and mRNA detection of classic cytokines in corresponding samples of serum, gingival tissue and gingival crevicular fluid from subjects with periodontitis.

BACKGROUND AND OBJECTIVE: Little is known about the correspondence of cytokines detected among the different biological matrices used in periodontal research and whether locally-detected cytokine mRNA can also be identified at the translated protein level. The aims of this study were to compare: (a) the detection of classic cytokines at protein level in corresponding samples of serum, gingival tissue and gingival crevicular fluid (GCF) in subjects with periodontitis and (b) the detection of cytokines at protein level in GCF and tissue with their detection at mRNA level in tissue. MATERIAL AND METHODS: Protein concentrations of IL-1ß, IL-6 and TNF-α were measured in corresponding samples of GCF, gingival tissue and serum from 125 subjects with chronic periodontitis by multiplex immunoassay. The mRNA levels of these cytokines were evaluated in the same gingival tissue by qPCR. RESULTS: The mean protein concentrations of IL-1ß and TNF-α were higher in tissue and GCF than in serum (P < 0.05). The mean protein concentration of IL-6 was higher in tissue, followed by serum and GCF, respectively (P < 0.05). Using serum as the gold standard, detection of IL-1ß in GCF and IL-6 in tissue had the highest sensitivity (100%), while detection of IL-6 in the GCF had the lowest sensitivity (77.9%). Using tissue as the gold standard, the detection sensitivities of IL-1ß, IL-6 and TNF-α were 93.6%, 78.4% and 94.2%, respectively, in GCF. Using mRNA as the gold standard, the detection of IL-1ß and IL-6 at the protein level in tissue (100.0%) had the highest sensitivity, while the detection of IL-6 in GCF (77.9%) had the lowest sensitivity. CONCLUSION: Tissue and GCF exhibited overall higher protein concentrations of cytokines than serum. GCF presented good reliability for identifying the target cytokines at protein level, when compared with detecting tissue cytokines at protein level. GCF and tissue presented high sensitivities for detecting cytokines at the protein level, when compared with detecting tissue cytokines at the mRNA level. The sensitivity for the identification of cytokines in the GCF depended on the target cytokine, where IL-6 was the least likely cytokine to be detected in this matrix.

An umbrella review on the effects of diabetes on implant failure and peri-implant diseases

Abstract The aim of this review is to summarize the evidence on associations between diabetes mellitus (DM) and complications around dental implants. Electronic database searches of MEDLINE, EMBASE, JBI Database of Systematic Reviews and Implementation Reports, Cochrane Database of Systematic Reviews and the PROSPERO register were performed from 1990 up to and including May 2018, using MeSH terms and other keywords. Systematic reviews and meta-analyses investigating the associations of DM and implant complications (failure, survival, bone loss, peri-implant diseases, and post-surgery infection) were eligible. The quality of the included reviews was determined using the Assessment of Multiple Systematic Reviews Tool 2 (AMSTAR 2). Twelve systematic reviews were included. Implant survival rates ranged from 83.5% to 100%, while implant failure rates varied from 0% to 14.3% for subjects with DM. The three meta-analyses performed for event "implant failure" reported no statistically significant differences between diabetic and non-diabetic subjects. An apparently increased risk of peri-implantitis is reported in patients with DM. According to the AMSTAR 2 classification, 50% of the reviews were classified as being of "critically low", 25% as of "low" and 25% as of "moderate" quality. Evidence indicates high levels of survival and low levels of failure of implants inserted in patients with DM. However, DM was assessed as a whole in the majority of studies and, the actual influence of hyperglycemia on implant survival/failure is still uncertain. DM/hyperglycemia seems to be associated with a high risk of peri-implantitis. However, this conclusion is based on a limited number of systematic reviews.