Use of Collagen Matrix Scaffolds as a Substitute for Soft Tissue Augmentation: Case Series.

INTRODUCTION: The presence of keratinized mucosa (KM) around natural teeth is believed to be beneficial in certain restorative, prosthetic, and orthodontic situations. Lack of adequate KM is common and predictably treated by autogenous gingival grafts (AGGs); however, AGGs have the disadvantages of harvest site morbidity, limited donor site availability, and compromised esthetics. CASE PRESENTATION: This case series presents the use of the xenogeneic porcine bilayer collagen matrix (BCM) in increasing the width of attached KM around natural teeth. Patients with a limited amount of KM, shallow vestibule, and aberrant frenum attachment were treated using this graft material. The patients were followed up to 4.5 years postoperatively and were evaluated regarding the amount of KM, gingival margin stability, and tissue esthetics. CONCLUSIONS: Within the limitations of the sample size of patients in this report, the BCM appears to be a viable alternative option to AGG for increasing the width of KM gingiva around teeth. This method resulted in gain of KM, gingival margin stability, vestibular deepening, aberrant frenum elimination, and favorable esthetics in terms of color matching, texture, and contour blending. This xenogeneic graft material could be used in cases where the autogenous graft supply is limited or in highly esthetically demanding cases. Additionally, it could be an alternative option when a second surgical site is not desired by the patient or a less invasive procedure is preferred by the clinician in certain medical conditions. Well-controlled long-term studies are required to validate our limited clinical observations.

Intestinal development and homeostasis require activation and apoptosis of diet-reactive T cells.

The impact of food antigens on intestinal homeostasis and immune function is poorly understood. Here, we explored the impact of dietary antigens on the phenotype and fate of intestinal T cells. Physiological uptake of dietary proteins generated a highly activated CD44+Helios+CD4+ T cell population predominantly in Peyer patches. These cells are distinct from regulatory T cells and develop independently of the microbiota. Alimentation with a protein-free, elemental diet led to an atrophic small intestine with low numbers of activated T cells, including Tfh cells and decreased amounts of intestinal IgA and IL-10. Food-activated CD44+Helios+CD4+ T cells in the Peyer patches are controlled by the immune checkpoint molecule PD-1. Blocking the PD-1 pathway rescued these T cells from apoptosis and triggered proinflammatory cytokine production, which in IL-10-deficient mice was associated with intestinal inflammation. In support of these findings, our study of patients with Crohn's disease revealed significantly reduced frequencies of apoptotic CD4+ T cells in Peyer patches as compared with healthy controls. These results suggest that apoptosis of diet-activated T cells is a hallmark of the healthy intestine.

The Role of Systems Biologic Approach in Cell Signaling and Drug Development Responses-A Mini Review.

The immune system is an integral aspect of the human defense system and is primarily responsible for and involved in the communication between the immune cells. It also plays an important role in the protection of the organism from foreign invaders. Recent studies in the literature have described its role in the process of hematopoiesis, lymphocyte recruitment, T cell subset differentiation and inflammation. However, the specific molecular mechanisms underlying these observations remain elusive, impeding the elaborate manipulation of cytokine sequential delivery in tissue repair. Previously, the discovery of new drugs and systems biology went hand in hand; although Systems biology as a term has only originated in the last century. Various new chemicals were tested on the human body, and studied through observation. Animal models replaced humans for initial trials, but the interactions, response, dose and effect between animals and humans could not be directly correlated. Therefore, there is a need to form disease models outside of human subjects to check the effectiveness and response of the newer natural or synthetic chemicals. These emulate human disease conditions wherein the behavior of the chemicals would be similar in the disease model and humans.

Surgical Management of Implant-Associated Gingival Fenestrations.

Soft tissue fenestrations are extremely rare in the natural dentition and have only recently been reported on dental implants. Although the pathogenesis of their formation is not completely understood, several predisposing risk factors have been identified, some of which may affect dental implants as well. This article presents a thorough review of the literature pertaining to gingival fenestration. It also describes the surgical management of lesions developed approximately six years following osseointegration of two dental implants.

Surgical Management of Implant-Associated Gingival Fenestrations.

Soft tissue fenestrations are extremely rare in the natural dentition and have only recently been reported on dental implants. Although the pathogenesis of their formation is not completely understood, several predisposing risk factors have been identified, some of which may affect dental implants as well. This article presents a thorough review of the literature pertaining to gingival fenestration. It also describes the surgical management of lesions developed approximately six years following osseointegration of two dental implants.

Regression of Calcium Channel Blocker--Induced Gingival Enlargement in the Absence of Periodontal Therapy.

AIM: To illustrate the negative effect of calcium channel blocker (CCB) drugs on the gingival tissues and the reversibility of these lesions. CASE DESCRIPTION: The authors examined a forty-eight year-old male patient with drug-induced gingival enlargement associated with diltiazem, a CCB drug. Prior to initiating the proposed periodontal treatment, the patient was advised to consult his physician, for a possible switch to a different anti-hypertensive drug. The patient returned to the clinic three months later with a significant regression of the gingival overgrowth, which was induced by the patient ceasing the prescribed regimen without medical consultation or periodontal intervention. CONCLUSION: Although CCBs are effective cardiovascular drugs, they can negatively impact the oral health by promoting gingival overgrowth in some patients. Substitution of these drugs is strongly recommended prior to any periodontal intervention in order to improve prognosis and prevent recurrence, and should be done only by the medical providers.

Lack of microbiota reduces innate responses and enhances adaptive immunity against Listeria monocytogenes infection.

The intestinal microbiota influences not only metabolic processes, but also the mucosal and systemic immune systems. Here, we compare innate and adaptive immune responses against the intracellular pathogen Listeria monocytogenes in germfree (GF) and conventional mice. We show that animals without endogenous microbiota are highly susceptible to primary infection with impaired activation and accumulation of phagocytes to the site of infection. Unexpectedly, secondary infection with otherwise lethal dose resulted in survival of all GF animals which cleared bacteria more rapidly and developed a stronger antilisterial CD8(+) memory T-cell response compared to conventional mice. In summary, lack of the intestinal microbiota impairs early innate immunity, but enhances activation and expansion of memory T cells.

The effect of long-term aspirin intake on the outcome of non-surgical periodontal therapy in smokers: a double-blind, randomized pilot study.

OBJECTIVE: The objective of this parallel, double-blind, randomized pilot study was to determine the effect of a daily dose of 325 mg of aspirin (ASA) on the clinical outcomes of scaling and root planing in a selected group of adult smokers. BACKGROUND: The response to periodontal therapy is inferior among smokers compared to non-smokers. Long-term intake of ASA has been shown to exert a positive impact on reducing both the prevalence and severity of periodontitis, among high-risk groups of subjects such as heavy smokers and diabetics. It is reasonable to assume that systemic administration of ASA in conjunction with reduction of the bacterial load by scaling and root planing may improve and prolong the benefits of periodontal therapy. To date, only few prospective interventional clinical studies have specifically addressed the periodontal needs of smokers. METHODS: The study includes 24 smokers. The following clinical parameters were measured preoperatively and at 3, 6, 9 and 12 mo postoperatively: (i) gingival index; (ii) plaque index; (iii) probing depth; (iii) probing attachment level; (iv) gingival recession; and (v) bleeding scores. Study subjects received scaling and root planing over several visits and were randomly assigned into two equal groups; a control group (C), which received a placebo and a test group (T), which took a daily dose of 325 mg ASA. No additional therapy was provided over the 1 year observation period. RESULTS: There were more statistically significant differences (p < 0.05; one- tailed) between pretest and posttest scores in the T group than in the C group. Mean percent increase in sites with probing depth 1-3 mm (T: 8.78; C: 7.21); mean percent reduction in sites with probing depth 4-6 mm (T: -7.25; C: -5.09 not statistically significant, NS); mean percent reduction in sites with probing depth ≥ 7 mm (T: -1.42; C: -02.09); mean percent reduction in sites with probing attachment level 3-4 mm (T: -3.63; C: 0.48 NS); mean percent reduction in sites with bleeding on probing (T: -12.37; C: -2.59 NS) (p < 0.05, NS). CONCLUSIONS: Daily intake of 325 mg of ASA following scaling and root planing improved treatment outcomes in smokers, without an increase in gingival bleeding tendency. ASA promoted a higher incidence of shallow pockets and more gain in attachment level.

Interplay between T(h)1 and T(h)17 effector T-cell pathways in the pathogenesis of spontaneous colitis and colon cancer in the Gαi2-deficient mouse.

Gαi2-deficient mice spontaneously develop colitis. Using xMAP technology and RT-PCR, we investigated cytokine/chemokine profiles during histologically defined phases of disease: (i) no/mild, (ii) moderate, (iii) severe colitis without dysplasia/cancer and (iv) severe colitis with dysplasia/cancer, compared with age-matched wild-type (WT) littermates. Colonic dysplasia was observed in 4/11 mice and cancer in 1/11 mice with severe colitis. The histology correlated with progressive increases in colon weight/cm and spleen weight, and decreased thymus weight, all more advanced in mice with dysplasia/cancer. IL-1ß, IL-6, IL-12p40, IL-17, TNF-α, CCL2 and CXCL1 protein levels in colons, but not small intestines increased with colitis progression and were significantly increased in mice with moderate and severe colitis compared with WT mice, irrespective of the absence/presence of dysplasia/cancer. CCL5 did not change during colitis progression. Colonic IL-17 transcription increased 40- to 70-fold in all stages of colitis, whereas IFN-γ mRNA was gradually up-regulated 12- to 55-fold with colitis progression, and further to 62-fold in mice with dysplasia/cancer. IL-27 mRNA increased 4- to 15-fold during the course of colitis, and colonic IL-21 transcription increased 3-fold in mice with severe colitis, both irrespective of the absence/presence of dysplasia/cancer. FoxP3 transcription was significantly enhanced (3.5-fold) in mice with moderate and severe colitis, but not in mice with dysplasia/cancer, compared with WT mice. Constrained correspondence analysis demonstrated an association between increased protein levels of TNF-α, CCL2, IL-1ß, IL-6 and CXCL1 and dysplasia/cancer. In conclusion, colonic responses are dominated by a mixed T(h)1/T(h)17 phenotype, with increasing T(h)1 cytokine transcription with progression of colitis in Gαi2(-/-) mice.

Management of oral melanin pigmentation.

Melanin is an endogenous pigment responsible for human tissue coloration of the skin, mucosa, hair, eyes and parts of the brain. In the skin, its function is protection from the harmful effects of UV radiation. Its purpose in oral tissues has not yet been determined. Oral pigmentation could be an esthetic issue for some patients, particularly when it is located on the anterior labial gingiva in individuals with a high smile line. This article presents and describes several different approaches for the management of oral melanin pigmentation.

Odontogenic keratocyst: a case report and review of an old lesion with new classification.

The odontogenic keratocyst (OKC) is distinctive among jaw cysts given its tendency toward recurrence and aggressive clinical behavior. This paper presents a well-documented case of OKC and a review of the diagnostic features, treatment modalities and new evidence supporting the reclassification and renaming of this unique pathologic process.

IL-13 promotes collagen accumulation in Crohn's disease fibrosis by down-regulation of fibroblast MMP synthesis: a role for innate lymphoid cells?

BACKGROUND: Fibrosis is a serious consequence of Crohn's disease (CD), often necessitating surgical resection. We examined the hypothesis that IL-13 may promote collagen accumulation within the CD muscle microenvironment. METHODS: Factors potentially modulating collagen deposition were examined in intestinal tissue samples from fibrotic (f) CD and compared with cancer control (C), ulcerative colitis (UC) and uninvolved (u) CD. Mechanisms attributable to IL-13 were analysed using cell lines derived from uninvolved muscle tissue and tissue explants. RESULTS: In fCD muscle extracts, collagen synthesis was significantly increased compared to other groups, but MMP-2 was not co-ordinately increased. IL-13 transcripts were highest in fCD muscle compared to muscle from other groups. IL-13 receptor (R) α1 was expressed by intestinal muscle smooth muscle, nerve and KIR(+) cells. Fibroblasts from intestinal muscle expressed Rα1, phosphorylated STAT6 in response to IL-13, and subsequently down-regulated MMP-2 and TNF-α-induced MMP-1 and MMP-9 synthesis. Cells with the phenotype KIR(+)CD45(+)CD56(+/-)CD3(-) were significantly increased in fCD muscle compared to all other groups, expressed Rα1 and membrane IL-13, and transcribed high levels of IL-13. In explanted CD muscle, these cells did not phosphorylate STAT6 in response to exogenous IL-13. CONCLUSIONS: The data indicate that in fibrotic intestinal muscle of Crohn's patients, the IL-13 pathway is stimulated, involving a novel population of infiltrating IL-13Rα1(+), KIR(+) innate lymphoid cells, producing IL-13 which inhibits fibroblast MMP synthesis. Consequently, matrix degradation is down-regulated and this leads to excessive collagen deposition.

CD4+FoxP3+ regulatory T cells from Gαi2-/- mice are functionally active in vitro, but do not prevent colitis.

BACKGROUND: Mice deficient in the inhibitory G protein subunit Gαi2 spontaneously develop a T helper 1 dominated colitis. We examined whether a defect in CD4(+)FoxP3(+) regulatory T cells (Treg) underpins the pathogenesis of colitis in the Gαi2(-/-) (Gαi2-deficient) colitis model. METHODOLOGY/PRINCIPAL FINDINGS: Using flow cytometry, we found that thymus and colonic lamina propria, but not spleen and mesenteric lymph nodes, of colitic Gαi2(-/-) mice contained increased frequencies of Treg, whereas FoxP3 expression intensity was similar in Gαi2(-/-) compared to Gαi2(+/-) or Gαi2(+/+) wild type (WT) mice. The frequency of CD4(+)FoxP3(+) T cells expressing CD103 was significantly increased in Gαi2(-/-) compared to WT mice. Treg in colons from WT mice clustered in the T cell areas of colonic lymphoid patches (CLP), with relatively few Treg in the lamina propria, as demonstrated by immunohistochemistry. In Gαi2(-/-) mice, CLP were not observed but lamina propria Treg were increased in number and frequency within the CD4(+) infiltrate, compared to WT mice. Using an in vitro co-culture system and flow cytometric analysis of cell division we could demonstrate that the in vitro suppressive function of WT and Gαi2(-/-) CD4(+)FoxP3(+) regulatory T cells (WT-Treg and KO-Treg) was indistinguishable, but that T effector cells (CD4(+)25(-) T cells) from Gαi2(-/-) mice were less readily suppressed than WT effectors (WT-Teff) by Treg from either source. However, neither WT nor Gαi2(-/-) Treg was able to suppress colitis induced by adoptive transfer of Gαi2(-/-) effector T cells (KO-Teff) to RAG2(-/-) recipients. The enhanced inflammatory activity of Gαi2(-/-) effectors was accompanied by increased expression of an effector/memory T cell phenotype and increased cytokine secretion, especially IL-4, IL-6 and IFN-γ. CONCLUSIONS: There is an increased frequency of Gαi2(-/-) Treg in the colon, and they demonstrate no endogenous functional defect. However, Gαi2(-/-) T effector cells are dramatically less susceptible to suppression in vitro, and in vivo, despite increased effective numbers of Treg, they cannot prevent disease.

Association of antimicrobial and clinical efficacy: periodontitis therapy with minocycline microspheres.

OBJECTIVE: The objective of this study was to investigate the association between the antimicrobial and clinical efficacy of minocycline hydrochloride microspheres when used adjunctively with scaling and root planing. METHODS: 127 subjects with moderate-to-advanced chronic periodontitis were randomly assigned to receive either minocycline microspheres plus scaling and root planing (n = 62) or scaling and root planing alone (n = 65). Deoxyribose nucleic acid analysis and clinical data were obtained at baseline and 30 days after treatment. End points included changes in the mean sum of red complex bacteria, pocket depth, number of deep pockets, bleeding on probing, and clinical attachment level from baseline to day 30. Regression analysis determined the association between microbiological and clinical efficacy. RESULTS: Minocycline microspheres plus scaling and root planing reduced pocket depth, the number of deep pockets and bleeding on probing, and increased clinical attachment level significantly more than scaling and root planing alone (p < 0.05). Comparing minocycline microspheres plus scaling and root planing with scaling and root planing alone, the number needed to treat for a 2 mm pocket depth reduction difference was 6.5. Pocket depth reduction correlated significantly with a decrease in the numbers and proportions of red complex bacteria. Minocycline microspheres significantly improved all clinical parameters compared to scaling and root planing alone. CONCLUSIONS: The addition of minocycline microspheres to scaling and root planing led to a greater reduction in the proportions and numbers of red complex bacteria. The reduction in pocket depth was significantly correlated with the reduction of the proportions and numbers of red complex bacteria. Additionally, there were statistically greater improvements in all clinical parameters examined.

Mechanical therapy with adjunctive minocycline microspheres reduces red-complex bacteria in smokers.

BACKGROUND: Smoking increases the risk for periodontal disease and reduces the healing response. We examined the antimicrobial and clinical effects of scaling and root planing (SRP) with and without minocycline HCl 1 mg microspheres (MM) relative to smoking status in subjects with periodontitis. METHODS: A total of 127 subjects (46 never smokers, 44 former smokers, and 37 current smokers) with moderate to advanced periodontitis were randomized to receive MM + SRP (N = 62) or SRP alone (N = 65). Subgingival plaque samples collected at baseline and day 30 were examined for the presence of 40 periodontal bacteria by DNA probe analysis. RESULTS: MM + SRP reduced red-complex bacteria (RCB) numbers and proportions to a greater extent than SRP alone, irrespective of smoking status. RCB numbers were not reduced by SRP in current smokers. The difference in the reduction in numbers of RCB by SRP relative to MM + SRP in current smokers was statistically significant (P <0.05). Numbers and proportions of orange complex bacteria (OCB) were reduced in all groups treated with MM + SRP. Proportions of OCB increased in current smokers treated with SRP alone. In current smokers, MM + SRP significantly reduced probing depth (PD), increased clinical attachment level (CAL), and reduced bleeding on probing (BOP) to a greater extent than SRP alone (P <0.05). CONCLUSIONS: SRP alone was ineffective at reducing numbers or proportions of RCB or OCB in current smokers, whereas MM + SRP significantly reduced both. MM + SRP also improved PD, BOP, and CAL to a greater extent than SRP alone independent of smoking status.

Minocycline HCl microspheres reduce red-complex bacteria in periodontal disease therapy.

BACKGROUND: The objective of this trial was to measure the antimicrobial effects of a minocycline HCl microsphere (MM) local drug-delivery system when used as an adjunct to scaling and root planing (SRP). DNA probe analysis for 40 bacteria was used to evaluate the oral bacteria of 127 subjects with moderate to advanced chronic periodontitis. METHODS: Subjects were randomly assigned to either SRP alone (N = 65) or MM + SRP (N = 62). The primary endpoints of this study were changes in numbers and proportions of the red-complex bacteria (RCB) and the sum of Porphyromonas gingivalis, Tannerella forsythia (formally T. forsythensis), and Treponema denticola relative to 40 oral bacteria at each test site from baseline to day 30. Numbers of RCB from the five test sites were averaged to provide a value for each subject. RESULTS: MM + SRP reduced the proportion of RCB by 6.49% and the numbers by 9.4 x 10(5). The reduction in RCB proportions and numbers by SRP alone (5.03% and 5.1 x 10(5), respectively) was significantly less. In addition, MM + SRP reduced probing depth by 1.38 mm (compared to 1.01 mm by SRP alone), bleeding on probing was reduced by 25.2% (compared to 13.8% by SRP alone), and a clinical attachment level gain of 1.16 mm (compared to 0.80 mm by SRP alone) was achieved. CONCLUSION: These observations support the hypothesis that RCBs are responsible for periodontal disease and that local antimicrobial therapy using MM + SRP effectively reduces numbers of RCBs and their proportions to a greater extent than SRP alone.

Segmented filamentous bacteria in a defined bacterial cocktail induce intestinal inflammation in SCID mice reconstituted with CD45RBhigh CD4+ T cells.

BACKGROUND: The aim was to analyze the influence of intestinal microbiota on the development of intestinal inflammation. We used the model of chronic inflammation that develops spontaneously in the colon of conventional severe combined immunodeficiency (SCID) mice restored with the CD45 RB(high) subset of CD4+T cells isolated from the spleen of normal BALB/c mice. METHODS: A CD4+CD45RB(high) subpopulation of T cells was purified from the spleen of conventional BALB/c mice by magnetic separation (MACS) and transferred into immunodeficient SCID mice. Germ-free (GF) SCID mice or SCID mice monoassociated with Enterococcus faecalis, SFB (segmented filamentous bacteria), Fusobacterium mortiferum, Bacteroides distasonis, and in combination Fusobacterium mortiferum + SFB or Bacteroides distasonis + SFB were used as recipients. SCID mice were colonized by a defined cocktail of specific pathogen-free (SPF) bacteria. Mice were evaluated 8-12 weeks after the cell transfer for clinical and morphological signs of inflammatory bowel disease (IBD). RESULTS: After the transfer of the CD4+CD45RB(high) T-cell subpopulation to SCID mice severe colitis was present in conventional animals and in mice colonized with a cocktail of SPF microflora plus SFB. Altered intestinal barrier in the terminal ileum of mice with severe colitis was documented by immunohistology using antibodies to ZO-1 (zona occludens). CONCLUSIONS: Only SFB bacteria together with a defined SPF mixture were effective in triggering intestinal inflammation in the model of IBD in reconstituted SCID mice, while no colitis was detected in GF mice or in mice colonized either with SPF microflora or monoassociated only with SFB or colonized by Bacteroides distasonis + SFB or Fusobacterium mortiferum + SFB.

Aberrant T-cell ontogeny and defective thymocyte and colonic T-cell chemotactic migration in colitis-prone Galphai2-deficient mice.

Galphai2-deficient mice, which spontaneously develop colitis, have previously been reported to have an increased frequency of mature, single positive thymocytes compared to wild-type mice. In this study we further characterized the intrathymic changes in these mice before and during overt colitis. Even before the onset of colitis, Galphai2(-/-) thymi weighed less and contained fewer thymocytes, and this was exacerbated with colitis development. Whereas precolitic Galphai2(-/-) mice had unchanged thymocyte density compared to Galphai2(+/-) mice of the same age, this was significantly decreased in mice with colitis. Thymic atrophy in Galphai2(-/-) mice involved mainly the cortex. Using a five-stage phenotypic characterization of thymocyte maturation based on expression of CD4, CD8, TCRalphabeta, CD69 and CD62L, we found that both precolitic and colitic Galphai2(-/-) mice had significantly increased frequencies of mature single-positive CD4(+) and CD8(+) medullary thymocytes, and significantly reduced frequencies and total numbers of immature CD4(+) CD8(+) double-positive thymocytes compared to Galphai2(+/-) mice. Furthermore, cortical and transitional precolitic Galphai2(-/-) thymocytes showed significantly reduced chemotactic migration towards CXCL12, and a trend towards reduced migration to CCL25, compared to wild-type thymocytes, a feature even more pronounced in colitic mice. This impaired chemotactic migration of Galphai2(-/-) thymocytes could not be reversed by increased chemokine concentrations. Galphai2(-/-) thymocytes also showed reduced expression of the CCL25 receptor CCR9, but not CXCR4, the receptor, for CXCL12. Finally, wild-type colonic lamina propria lymphocytes migrated in response to CXCL12, but not CCL25 and, as with thymocytes, the chemokine responsiveness was significantly reduced in Galphai2(-/-) mucosal lymphocytes.

The effect of weaning on the clonality of alpha beta T-cell receptor T cells in the intestine of GF and SPF mice.

In humans, intestinal antigen exposure during neonatal life influences the T-cell receptor (TCR) repertoire. To define the relative effects of bacteria and food antigens in early life, we examined TCR diversity in the intestine of SPF and GF mice. TCR repertoire was assessed at a single time point pre-, peri- and post-weaning in the small and large intestine of SPF and GF mice using spectratyping and/or TCR-beta-chain sequencing. There was good concordance of data obtained by the two techniques. In SPF mice, the repertoire was polyclonal shortly after birth in the small and large intestine. After weaning, there was a significant change towards an oligoclonal repertoire in the small intestine. There was some evidence that specific clones were shared between the small and large intestine. In contrast, in GF mice, the repertoire was oligoclonal after birth, and remained restricted. These data show: firstly, that under SPF conditions, the intestine is seeded with a diverse T-cell population that becomes oligoclonal around the time of weaning; secondly, that GF mice were oligoclonal at each time point.