Contact allergies to dental materials in patients.

BACKGROUND: Concerns regarding contact allergies and intolerance reactions to dental materials are widespread among patients. Development of novel dental materials and less frequent amalgam use may alter sensitization profiles in patients with possible contact allergy. OBJECTIVES: To analyse current sensitization patterns to dental materials in patients with suspected contact allergy. METHODS: This retrospective, multicentre analysis from the Information Network of Departments of Dermatology (IVDK) selected participants from 169 834 people tested in 2005-2019 and registered with (i) an affected area of 'mouth' (and 'lips'/'perioral'), (ii) with the dental material in question belonging to one of three groups (dental filling materials, oral implants or dentures or equivalents) and (iii) with patch-testing done in parallel with the German baseline series, (dental) metal series and dental technician series. RESULTS: A total of 2730 of 169 834 tested patients met the inclusion criteria. The patients were predominantly women (81.2%) aged ≥ 40 years (92.8%). The sensitization rates with confirmed allergic contact stomatitis in women (n = 444) were highest for metals (nickel 28.6%, palladium 21.4%, amalgam 10.9%), (meth)acrylates [2-hydroxyethyl methacrylate (HEMA) 4.8%] and the substances propolis (6.8%) and 'balsam of Peru' (11.4%). The most relevant acrylates were HEMA, 2-hydroxypropyl methacrylate, methyl methacrylate, ethylene glycol dimethacrylate and pentaerythritol triacrylate. Few men were diagnosed with allergic contact stomatitis (n = 68); sensitization rates in men were highest for propolis (14.9%) and amalgam (13.6%). CONCLUSIONS: Allergic contact stomatitis to dental materials is rare. Patch testing should not only focus on metals such as nickel, palladium, amalgam and gold, but also (meth)acrylates and the natural substances propolis and 'balsam of Peru'.

Interleukin-10 and Interleukin-1ß Cytokines Expression in Leukocytes of Patients with Chronic Peri-Mucositis.

BACKGROUND The purpose of the present research is to analyze the effect of polyphenols and flavonoids substrat (PFS) from plants Calendula officinalis, Salvia fruticosa, Achillea millefolium, and propolis as immunomodulatory in the production of interleukin (IL)-1ß and IL-10 in peripheral blood leukocytes medium (PBLM) in patients who were diagnosed with mucositis of peri-implant tissue compared to patients with healthy implant tissue. It was hypothesized that IL-1ß and IL-10 contribute to the inflammation processes noticed in the diseases of peri-implant tissues. MATERIAL AND METHODS Sixty non-smoking patients were included in this study: patients with healthy implants (HP group) and patients with peri-implant mucositis (MP group). Peri-mucositis was diagnosed by radiologic and clinical examination. The PBLM from MP were treated with PFS at various concentrations. The levels of IL-10 and IL-1ß excreted by the PBLM stimulated and unstimulated with viable Porphyromonas gingivalis test-tube were committed by the enzyme amplified immunoassay sensitivity method. RESULTS Unstimulated and stimulated PBLM and treatment with 5.0 mg/mL or 10.0 mg/mL of PFS in the MP group produced significantly higher levels IL-10 (P<0.001) that analogous mediums of the HP group. The levels of IL-1ß decreased more considerably in the stimulated PBLM of the MP group than in those of HP group (P<0.001) after the treatment with PFS at only 10.0 mg/mL concentration. CONCLUSIONS Theses results suggest that the solution of PFS might offer a new potential for the development of a new therapeutic path to prevent and treat peri-implant mucositis.

Evaluation of the relationship between salivary concentration of anti-heat shock protein immunoglobulin and clinical manifestations of Behçet's disease.

OBJECTIVE: This study investigated the relationship between the concentration of anti-heat shock protein (HSP) 60 antibody in resting saliva and the severity of Behçet's disease (BD). METHOD: Sixty-five patients diagnosed with BD at Tokyo Medical and Dental University Hospital were enrolled in this study. Based on clinical severity scores, patients were categorized as having mild, moderate, or severe BD. Periodontal status was evaluated with the Community Periodontal Index (CPI), and anti-HSP60 antibody concentrations in resting saliva were measured with an enzyme-linked immunosorbent assay. RESULTS: The mean antibody concentration in patients in the moderate group was significantly higher than concentrations in the mild and severe groups. No significant difference was found between the mild and severe groups. Gingival inflammation, identified with the CPI, was associated with a higher antibody concentration. The antibody concentration in patients who had stomatitis for more than 2 weeks was significantly higher than in those with stomatitis for less than 2 weeks. The antibody concentration in patients who had taken colchicine was significantly lower than that in subjects who had not. CONCLUSION: These results suggest that the concentration of anti-HSP60 antibody in resting saliva may be effective as a non-invasive indicator for the diagnosis (screening) and prognostication of BD.

The relationship between oral mucositis and levels of pro-inflammatory cytokines in serum and in gingival crevicular fluid in allogeneic stem cell recipients.

PURPOSE: Oral mucositis (OM) is a severe side effect of conditioning for allogeneic hematopoietic stem cell transplantation (HSCT). The aim of the present study was to investigate the relationship between oral mucositis and the levels of pro-inflammatory cytokines-both in serum and in gingival crevicular fluid (GCF), in relation to different conditioning regimens. METHODS: We analyzed the levels of pro-inflammatory cytokines IL-1ß, TNF-α, IL-6, and IL-7, as well as anti-inflammatory cytokine IL-10 in gingival crevicular fluid (GCF) and in serum from 43 HSCT patients. Twenty-five received reduced intensity conditioning (RIC) and 18 received myeloablative conditioning (MAC). Cytokine levels were determined in GCF and serum before the start of conditioning, and 1 week and 1 month after HSCT. All patients experienced OM with a median score of 2.1 and median peak on day 11. RESULTS: There was a significant correlation between OM and MAC (p = 0.035). There were no significant differences in GCF volume at the three time points examined. The levels of IL-6 in GCF increased 1 week after transplantation and then returned to baseline (p < 0.001). The levels of IL-10 in GCF decreased after HSCT (p < 0.001) and remained unchanged. The levels of IL-6 in serum significantly (p < 0.001) increased 1 week after HSCT and decreased to baseline levels after 1 month. The levels of IL-10 in serum significantly (p = 0.02) increased 1 month after HSCT. CONCLUSION: No correlations between cytokine levels in gingival crevicular fluid and oral mucositis were observed. There was a correlation between severity of OM score and increase in IL-6 in serum. No correlations between cytokine levels in gingival crevicular fluid and in serum were observed.

Saliva versus peri-implant inflammation: quantification of IL-1ß in partially and totally edentulous patients.

The aim of this study was to investigate the potential use of salivary IL1ß in early-stage diagnostics of peri-implant inflammation in partially and totally edentulous patients rehabilitated with dental implants. Patients were classified according to peri-implant probing depth and bleeding upon probing in groups of healthy individuals or in groups of individuals with peri-implant inflammation. Data on plaque index, clinical attachment loss, suppuration, and mobility were also assessed. Saliva was collected without stimulation, and the levels of IL-1ß were determined by ELISA. Healthy groups demonstrated significantly lower levels of IL-1ß compared with the inflammation groups. No difference in IL-1ß levels was observed between partially edentulous or totally edentulous patients. Salivary IL-1ß may be useful for the diagnosis and monitoring of early peri-implant inflammation, particularly in edentulous patients.

The role of probiotic therapy on clinical parameters and human immune response in peri-implant diseases: a systematic review and meta-analysis of randomized clinical studies.

Background: Peri-implant diseases (peri-implant mucositis and peri-implantitis) are pathologies of an infectious-inflammatory nature of the mucosa around dental implants. Probiotics are microorganisms that regulate host immunomodulation and have shown positive results in the treatment of peri-implant diseases. The objective of the systematic review and meta-analysis was to evaluate the efficacy of probiotics in the treatment of peri-implant oral diseases. Methods: According to the PRISMA guidelines, the research question was established: Are probiotics able to favorably modify clinical and immunological biomarkers determinants of peri-implant pathologies? and an electronic search of the databases MEDLINE/PubMed, Embase, Cochrane Central, Web of Science, (until December 2023) was performed. Inclusion criteria were established for intervention studies (RCTs), according to the PICOs strategy in subjects with peri-implant pathology (participants), treated with probiotics (intervention) compared to patients with conventional treatment or placebo (control) and evaluating the response to treatment (outcomes). Results- 1723 studies were obtained and 10 were selected. Risk of bias was assessed using the Cochrane Risk of Bias Tool and methodological quality using the Joanna Briggs Institute for RCTs. Two meta-analyses were performed, one to evaluate probiotics in mucositis and one for peri-implantitis. All subgroups were homogeneous (I2 = 0%), except in the analysis of IL-6 in mucositis (I2 = 65%). The overall effect was favorable to the experimental group in both pathologies. The analysis of the studies grouped in peri-implantitis showed a tendency to significance (p=0.09). Conclusion: The use of probiotics, as basic or complementary treatment of peri-implant diseases, showed a statistically significant trend, but well-designed studies are warranted to validate the efficacy of these products in peri-implant pathologies.

Interleukins 1ß and 10 expressions in the periimplant crevicular fluid from patients with untreated periimplant disease.

PURPOSE: To analyze the interleukin (IL)-1ß and IL-10 expressions in periimplant crevicular fluid (PICF) in healthy and diseased regions to elucidate the inflammatory process around implants and its influence on clinical diagnosis. MATERIALS AND METHODS: PICF samples from 30 patients were analyzed for IL-1ß and IL-10 concentrations by enzyme-linked immunosorbent assay. Patients were divided in Groups A (health), B (mucositis), and C (periimplantitis). Plaque accumulation, periodontal phenotype (PP), depth on probing, and history of periodontitis (HP) were evaluated. RESULTS: IL-1ß levels were lower in healthy group compared with Groups B (P < 0.0005) and C (P < 0.001). IL-10 levels were higher in Groups A compared with B (P = 0.033) and C (P = 0.0001). Patients with HP and thin PP had 9 and 4.5 times more chance of presenting disease, respectively. CONCLUSIONS: Lower IL-1ß and higher IL-10 levels characterized healthy periimplant conditions, which demonstrate the anti-inflammatory predominance in sites without disease signs. IL-10 levels decrease significantly according to increase of disease status. Therefore, its levels can differentiate healthy, mucositis, and periimplantitis. Thin PP and HP are associated with periimplant disease. These findings suggest the use of ILs as a biochemical marker for early diagnosis of periimplant disease.

Proinflammatory cytokines during the initial phase of oral mucositis in patients with acute lymphoblastic leukaemia.

OBJECTIVE: The aim of the study was to compare the production of proinflammatory cytokines during the initial phase of mucositis in patients with acute lymphoblastic leukaemia. METHODS: A randomized, controlled clinical trial was carried out. Cytokine levels were determined in blood and saliva using ELISA, three times after the administration of methotrexate and only once in the control group. RESULTS: Comparison of the results showed significant differences for IL-6 and TNF-α in blood and IL-6 in saliva. CONCLUSION: It would seem that 96 h is an ideal time for determining the parameters evaluated both in blood and in saliva.

[A retrospective study of oral adverse events with colorectal cancer chemotherapy using bevacizumab].

PURPOSE: We encountered serious oral mucositis in some patients undergoing colorectal chemotherapy with bevacizumab. We retrospectively investigated the role bevacizumab plays in the occurrence of oral mucositis. SUBJECTS AND METHODS: Between January 2008 and December 2009, we encountered 11 patients for whom chemotherapy with bevacizumab had resulted in oral mucositis. The patients included 5 men and 6 women, with a mean age of 67. 9 years(range, 62-76 years). Among the patients, 5 had grade 1 oral mucositis, 3 had grade 2, and 3 had grade 3. We analyzed the risk factors, grades, symptoms, and treatments of oral mucositis in these patients. RESULTS: In 6 patients, bevacizumab was administered in combination with mFOLFOX6, and in 5 patients, bevacizumab was administered in combination with FOLFIRI. Seven patients had undergone prior treatment without the occurrence of serious oral mucositis. With respect to oral health, 8 patients had periodontal disease, 7 had dental caries, 3 wore dentures, 3 exhibited poor oral self-care, and 2 had diabetes; in addition, 2 patients were smokers. Symptoms of oral mucositis included mucosal reddening in 11 patients, oral mucosal erosion or ulcer in 7, fungus infection in 6, aphtha in 7, pseudomembrane formation in 3, and poor oral intake in 2. All the patients had oral mucositis at the occlusal line of the buccal mucosa. The treatment for oral mucositis included polaprezinc. CONCLUSION: Because many factors influence the development of oral mucositis, determining the specific cause of oral mucositis is difficult. Bevacizumabmay possibly decrease the VEGF levels in saliva and delay wound healing in oral mucositis. Therefore, oral mucositis may be caused not only by diabetes and poor oral self-care but by bevacizumab.

Periodontitis as a potential risk factor for peri-implantitis.

OBJECTIVES: To review the literature regarding the possible association between a previous history of periodontitis and peri-implantitis. MATERIAL AND METHODS: A search of MEDLINE as well as a manual search of articles were conducted. Publications and articles accepted for publication up to January 2008 were included. RESULTS: Out of 951 papers retrieved, a total of three papers were selected for the review. Thus, the available evidence for an association between periodontitis and peri-implantitis is scarce. CONCLUSIONS: Based on three studies with a limited number of patients and considerable variations in study design, different definitions of periodontitis, and confounding variables like smoking that not been accounted for, this systematic review indicates that subjects with a history of periodontitis may be at greater risk for peri-implant infections. It should, however, be stressed that the data to support this conclusion are not very robust.

Effect of anti-infective mechanical therapy on clinical parameters and cytokine levels in human peri-implant diseases.

BACKGROUND: The objectives of this study were to clinically and immunologically assess the effects of mechanical anti-infective therapies for mucositis and peri-implantitis and to compare the levels of cytokines in untreated and treated peri-implant diseased sites to healthy ones. METHODS: Titanium dental implants were assigned to one of the following groups: healthy (n = 10) = control; mucositis (n = 10) = mechanical debridement using abrasive sodium carbonate air-powder and resin curets; and peri-implantitis (n = 20) = open surgical debridement using abrasive sodium carbonate air-powder and resin curets. Visible plaque accumulation, marginal bleeding, bleeding on probing, suppuration, and probing depth were assessed at baseline for all groups and at 3 months after therapies for diseased groups. At these times, the total amounts of interleukin (IL)-4, -10, and -12, tumor necrosis factor-alpha (TNF-alpha), receptor activator of nuclear factor-kappa B ligand (RANKL), and osteoprotegerin (OPG) in the peri-implant crevicular fluid (PICF) were measured by enzyme-linked immunosorbent assay. RESULTS: At 3 months, the anti-infective treatments resulted in a significant improvement in all clinical parameters for mucositis and peri-implantitis (P <0.05). Moreover, the total amounts of TNF-alpha in PICF were significantly higher in untreated diseased implants compared to healthy ones, and the OPG/RANKL ratio was higher for healthy implants than for untreated peri-implantitis (P <0.05). TNF-alpha levels were significantly reduced for both diseased groups (P <0.05), achieving the same level as the healthy group at 3 months after therapies (P >0.05). CONCLUSION: The proposed anti-infective therapies may locally modulate the levels of TNF-alpha and the OPG/RANKL ratio and improve clinical parameters around peri-implant tissues.

On inflammation-immunological balance theory-A critical apprehension of disease concepts around implants: Mucositis and marginal bone loss may represent normal conditions and not necessarily a state of disease.

BACKGROUND: Oral implants have displayed clinical survival results at the 95%-99% level for over 10 years of follow up. Nevertheless, some clinical researchers see implant disease as a most common phenomenon. Oral implants are regarded to display disease in the form of mucositis or peri-implantitis. One purpose of the present article is to investigate whether a state of disease is necessarily occurring when implants display soft tissue inflammation or partially lose their bony attachment. Another purpose of this article is to analyze the mode of defense for implants that are placed in a bacteria rich environment and to analyze when an obtained steady state between tissue and the foreign materials is disturbed. MATERIALS AND METHODS: The present article is authored as a narrative review contribution. RESULTS: Evidence is presented that further documents the fact that implants are but foreign bodies that elicit a foreign body response when placed in bone tissue. The foreign body response is characterized by a bony demarcation of implants in combination with a chronic inflammation in soft tissues. Oral implants survive in the bacteria-rich environments where they are placed due to a dual defense system in form of chronic inflammation coupled to immunological cellular actions. Clear evidence is presented that questions the automatic diagnostics of an oral implant disease based on the finding of so called mucositis that in many instances represents but a normal tissue response to foreign body implants instead of disease. Furthermore, neither is marginal bone loss around implants necessarily indicative of a disease; the challenge to the implant represented by bone resorption may be successfully counteracted by local defense mechanisms and a new tissue-implant steady state may evolve. Similar reactions including chronic inflammation occur in the interface of orthopedic implants that display similarly good long-term results as do oral implants, if mainly evaluated based on revision surgery in orthopedic cases. The most common mode of failure of orthopedic implants is aseptic loosening which has been found coupled to a reactivation of the inflammatory- immune system. CONCLUSIONS: Implants survive in the body due to balanced defense reactions in form of chronic inflammation and activation of the innate immune system. Ten year results of oral and hip /knee implants are hence in the 90+ percentage region. Clinical problems may occur with bone resorption that in most cases is successfully counterbalanced by the defense/healing systems. However, in certain instances implant failure will ensue characterized by bacterial attacks and/or by reactivation of the immune system that now will act to remove the foreign bodies from the tissues.

The dentist's role in the prevention and management of necrotizing stomatitis in the immunosuppressed.

Advances in transplant medicine and availability of effective immunosuppressive regimens have dramatically improved survival for patients afflicted with end-stage organ failure. However, chronic immunosuppression predisposes transplant patients to infection caused by a wide spectrum of endogenous or exogenous pathogens as well as necrotizing periodontal conditions. This article reviews clinical features, diagnosis, and management of necrotizing stomatitis in the context of therapeutic immunosuppression and discusses the integral function of dentists in eliminating oral foci of infection in preparation for transplantation as well as life-long maintenance of oral health post-transplant. We also present a renal transplant patient who developed massive soft and hard tissue necrosis in the anterior mandible. Disproportionate periodontal destruction in relation to local factors raised suspicion of iatrogenic overimmunosuppression, and he was hospitalized for management of profound neutropenia.

Evaluation of the efficacy of the subcutaneous low recombinant feline interferon-omega administration protocol for feline chronic gingivitis-stomatitis in feline calicivirus-positive cats.

We investigated the clinical effectiveness of subcutaneous (SC) administration of recombinant feline interferon-omega (rFeIFN-ω) at a dose of 1 M unit (MU)/kg body weight (bw) for the treatment of feline chronic gingivitis-stomatitis (FCGS) in cats infected with feline calicivirus (FCV). Among the 17 cats used in this study, there were 13 FCV-positive cats (FCVI group), which were subcutaneously injected with rFeIFN-ω. The remaining four FCV-positive cats (FCVC group) were treated with SC corticosteroid. SC injection of rFeIFN-ω was given once daily on days 1, 2, 3, 7, 8, 9, 14, and 21. Corticosteroid was subcutaneously injected at a dose of 1.0 mg/kg bw, at the same intervals as rFeIFN-ω. Clinical symptoms (salivation, pain at opening the mouth, halitosis, mandibular lymphadenopathy, and all four symptoms combined [defined as "total clinical symptoms"]) and stomatitis (the degree and extent of inflammation, bleeding from the lesion, and all three items combined [defined as "total stomatitis"]) were scored on days 0, 7, 14, 21, and 28. FCV RNAs was quantified by real-time polymerase chain reaction and the percent increase in viral copy numbers was calculated using the values on days 0 and 28. In the FCVI group, significant differences were observed in the score for clinical symptom (salivation) score and in the total clinical symptom score within the group (P = 0.018 and 0.008, respectively). Significant differences within the group were also observed in the scores for the degree and extent of inflammation in stomatitis and in the total stomatitis score (P = 0.003, 0.007, and 0.003, respectively). The total score, defined as the clinical score plus the stomatitis score, was on days 7, 14, 21 and 28 than on day 0 (p = 0.006, .0003, 0.002 and 0.002, respectively). In the FCVI group, significant difference was observed between on days 0 and on 21 (p = 0.023). The percentage change in the number of polymerase chain reaction cycles required to amplify the viral RNA was positive (indicating viral reduction) in the FCVI group, but was negative in the FCVC group. These results demonstrate that SC administration of rFeIFN-ω under the current protocol improves stomatitis by inhibiting FCV proliferation in FCV-positive cats with FCGS.

p38 MAPK signaling in oral-related diseases.

Multiple dental diseases are characterized by chronic inflammation, due to the production of cytokines, chemokines, and prostanoids by immune and non-immune cells. Membrane-bound receptors provide a link between the extracellular environment and the initiation of intracellular signaling events that activate common signaling components, including p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and nuclear factor (NF)-kappaB. Although ERK pathways regulate cell survival and are responsive to extracellular mitogens, p38 MAPK, JNK, and NF-kappaB are involved in environmental stress responses, including inflammatory stimuli. Over the past decade, significant advances have been made relative to our understanding of the fundamental intracellular signaling mechanisms that govern inflammatory cytokine expression. The p38 MAPK pathway has been shown to play a pivotal role in inflammatory cytokine and chemokine gene regulation at both the transcriptional and the post-transcriptional levels. In this review, we present evidence for the significance of p38 MAPK signaling in diverse dental diseases, including chronic pain, desquamative disorders, and periodontal diseases. Additional information is presented on the molecular mechanisms whereby p38 signaling controls post-transcriptional gene expression in inflammatory states.

Review: allergic contact stomatitis.

Allergic contact stomatitis (ACS) is an oral mucosal immunoinflammatory disorder variably characterized clinically by erythematous plaques, vesiculation, ulceration, and/or hyperkeratosis and by pain, burning sensation, or itchiness. ACS is brought about by a T cell-mediated, delayed hypersensitivity immune reaction generated by a second or subsequent contact exposure of an allergen with the oral mucosa, in a genetically susceptible, sensitized subject. Lichenoid contact reaction is a variant of ACS brought about by direct contact with the oral mucosa of certain metals in dental restorations. The features of ACS are neither clinically nor histopathologically specific, so the diagnosis is usually presumptive and can only be confirmed by resolution of the inflammation after withdrawal or removal of the suspected causative allergen. When ACS is suspected but an allergen cannot be identified, patch testing is necessary. In persistent cases, topical corticosteroids are the treatment of choice, but for severe and extensive lesions, systemic corticosteroid and systemic antihistamines may be indicated. In this short review, we highlight the clinical, immunologic, and histopathological features of ACS, and provide some guidelines for diagnosis and management.

Clinical, Immune, and Microbiome Traits of Gingivitis and Peri-implant Mucositis.

Tissues surrounding dental implants and teeth develop clinical inflammation in response to microbial stimuli. However, the literature suggests that differences exist in the microbial insult and inflammatory responses leading to gingivitis and peri-implant mucositis. In this pilot study, the authors use for the first time a systems biology approach to comprehensively evaluate clinical parameters, selected inflammatory markers, and the microbiome of subject-matched tooth and implant sites during native inflammation and in response to experimental plaque accumulation. Fifteen subjects with 2 posterior implants and corresponding contralateral teeth were examined at enrollment; at day 0, after reinstitution of gingival/mucosal health; at days 7, 14, and 21, during stent-mediated oral hygiene (OH) abstention; and at day 42, after resumption of OH. The subgingival microbiome was evaluated via 16S rRNA gene sequencing and 8 selected inflammatory markers measured in crevicular fluid. Comparison of teeth and implants via general linear models based on orthogonal polynomials showed similar responses in clinical parameters, inflammatory mediators, and proportions of individual microbial taxa during OH abstention. Implants, however, accumulated less plaque and underwent more heterogeneous shifts in microbiome structure. A multilevel, within-group, sparse partial least squares analysis of covariation of microbial, inflammatory, and clinical parameters throughout all study visits found inflammation around teeth and implants positively correlated with IL-1 alpha and IL-1 beta and with the proportions of Selenomonas, Prevotella, and 5 species-level phylotypes. Gingivitis, however, showed a stronger positive correlation with lactoferrin and IL-1ra and a stronger negative correlation with Rothia. Peri-implant mucositis, on the contrary, correlated positively with certain microbial taxa not associated with gingivitis by a previous study or the current one. In summary, differences existed between implants and tooth sites in microbiome evolution during OH abstention and in the correlation of specific inflammatory mediators and microbial taxa with clinical inflammation. Common biological features, however, were also identified for gingivitis and mucositis.

Analysis of CD15, CD57 and HIF-1α in biopsies of patients with peri-implantitis.

Peri-implantitis is an infectious disease characterized by inflammation of the tissues surrounding the implant, bleeding on probing with or without suppuration, and bone loss. Peri-implant lesions contain a leukocyte infiltrate of plasma cells, lymphocytes, macrophages and neutrophils. A survey of the literature did not show any studies reporting an association between hypoxia and peri-implantitis. The aim of the present cross-sectional study was to evaluate histological changes and immunostaining for CD15, CD57 and HIF-1α in the peri-implant mucosa of patients with and without peri-implantitis. Mucosal biopsies were obtained from 18 patients with peri-implantitis and 10 control subjects without peri-implantitis at a private health care center between 2010 and 2012. The sections were fixed in 10% buffered formalin, processed and embedded in paraffin for histopathological and immunohistochemical study. Acanthosis, spongiosis and exocytosis were observed in both groups, with no significant difference between them. The peri-implantitis group showed increased immunostaining for CD15, a neutrophil marker, and HIF-1α, a tissue hypoxia marker, but no significant difference in immunostaining for CD57, a Natural Killer cell marker. The increase in neutrophil (CD15) and hypoxia (HIF-1α) markers in patients with peri-implantitis suggests an active participation of neutrophils and hypoxia in the pathogenesis of this disease. Since the present study was the first to evaluate the expression of CD15, CD57 and HIF-1α in peri-implant tissues, further studies should be performed to better understand the role of these molecules in peri-implantitis.

Implant wear induces inflammation, but not osteoclastic bone resorption, in RANK(-/-) mice.

Signaling of RANK (receptor activator of nuclear factor kappa B) through its ligand RANKL appears critical in osteolysis associated with aseptic loosening (AL). The purpose of this study was to investigate the role of RANK in a murine osteolysis model developed in RANK knockout (RANK(-/-)) mice. Ultra high molecular weight polyethylene (UHMWPE) debris was introduced into established air pouches on RANK(-/-) mice, followed by implantation of calvaria bone from syngeneic littermates. Wild type C57BL/6 (RANK(+/+)) mice injected with either UHMWPE or saline alone were included in this study. Pouch tissues were collected 14 days after UHMWPE inoculation for molecular and histology analysis. Results showed that UHMWPE stimulation induced strong pouch tissue inflammation in RANK(-/-) mice, as manifested by inflammatory cellular infiltration, pouch tissue proliferation, and increased gene expression of IL-1beta, TNFalpha, and RANKL. However, the UHMWPE-induced inflammation in RANK(-/-) mice was not associated with the osteoclastic bone resorption observed in RANK(+/+) mice. In RANK(+/+) mice subjected to UHMWPE stimulation, a large number of TRAP(+) cells were found on the implanted bone surface, where active osteoclastic bone resorption was observed. No TRAP(+) cells were found in UHMWPE-containing pouch tissues of RANK(-/-) mice. Consistent with the lack of osteoclastic activity shown by TRAP staining, no significant UHMWPE particle-induced bone resorption was found in RANK(-/-) mice. A well preserved bone collagen content (Van Gieson staining) and normal plateau surface contour [microcomputed tomography (microCT)] of implanted bone was observed in RANK(-/-) mice subjected to UHMWPE stimulation. In conclusion, this study provides the evidence that UHMWPE particles induce strong inflammatory responses, but not associated with osteoclastic bone resorption in RANK(-/-) mice. This indicates that RANK signaling is essential for UHMWPE particle-induced osteoclastic bone resorption, but does not participate in UHMWPE particle-induced inflammatory response.

Therapeutic Efficacy of Fresh, Autologous Mesenchymal Stem Cells for Severe Refractory Gingivostomatitis in Cats.

UNLABELLED: Mesenchymal stem cells (MSCs) are a promising therapy for immune-mediated and inflammatory disorders, because of their potent immunomodulatory properties. In this study, we investigated the use of fresh, autologous, adipose-derived MSCs (ASCs) for feline chronic gingivostomatitis (FCGS), a chronic, debilitating, idiopathic, oral mucosal inflammatory disease. Nine cats with refractory FCGS were enrolled in this pilot study. Each cat received 2 intravenous injections of 20 million autologous ASCs, 1 month apart. Oral biopsies were taken before and at 6 months after the first ASC injection. Blood immune cell subsets, serum protein, and cytokine levels were measured at 0, 1, 3, and 6 months after treatment to assess immunomodulatory effects. Seven of the 9 cats completed the study. Five cats responded to treatment by either complete clinical remission (n=3) or substantial clinical improvement (n=2). Two cats were nonresponders. Cats that responded to treatment also exhibited systemic immunomodulation demonstrated by decreased numbers of circulating CD8+ T cells, a normalization of the CD4/CD8 ratio, decreased neutrophil counts, and interferon-γ and interleukin (IL)-1ß concentration, and a temporary increase in serum IL-6 and tumor necrosis factor-α concentration. No clinical recurrence has occurred following complete clinical remission (follow-up of 6-24 months). In this study, cats with <15% cytotoxic CD8 T cells with low expression of CD8 (CD8lo) cells were 100% responsive to ASC therapy, whereas cats with >15% CD8lo cells were nonresponders. The relative absence of CD8lo cells may be a biomarker to predict response to ASC therapy, and may shed light on pathogenesis of FCGS and mechanisms by which ASCs decrease oral inflammation and affect T-cell phenotype. SIGNIFICANCE: This study is the first to demonstrate the safety and efficacy of fresh, autologous, adipose-derived stem cell systemic therapy for a naturally occurring, chronic inflammatory disease in cats. The findings demonstrate that this therapy resulted in complete clinical and histological resolution or reduction in clinical disease severity and immune modulation in most cats. This study also identified a potentially useful biomarker that could dictate patient enrollment and shed light on immune modulation mechanism. As a naturally occurring animal model, FCGS also provides a strategic platform for potentially translatable therapy for the treatment of human oral inflammatory disease.