Potential application of immunotherapy for modulation of pulp inflammation: opportunities for vital pulp treatment.

Caries results in the demineralization and destruction of enamel and dentine, and as the disease progresses, irreversible pulpitis can occur. Vital pulp therapy (VPT) is directed towards pulp preservation and the prevention of the progression of inflammation. The outcomes of VPT are not always predictable, and there is often a poor correlation between clinical signs and symptoms, and the events occurring at a molecular level. The inflamed pulp expresses increased levels of cytokines, including tumour necrosis factor (TNF)-α, interleukin (IL)-1α, IL-1ß, IL-4, IL-6, IL-8, IL-17 and IL-23, which recruit and drive a complex cellular immune response. Chronic inflammation and sustained cytokine release can result in irreversible pulp damage and a decreased capacity for tissue healing. Other chronic inflammatory diseases, such as psoriasis, inflammatory bowel diseases and rheumatoid arthritis, are also characterized by an dysregulated immune response composed of relatively high cytokine levels and increased numbers of immune cells along with microbial and hard-soft tissue destructive pathologies. Whilst anti-cytokine therapies have been successfully applied in the treatment of these diseases, this approach is yet to be attempted in cases of pulp inflammation. This review therefore focuses on the similarities in the aetiology between chronic inflammatory diseases and pulpitis, and explores how anti-cytokine therapies could be applied to manage an inflamed pulp and facilitate healing. Further proof-of-concept studies and clinical trials are justified to determine the effectiveness of these treatments to enable more predictable outcomes in VPT.

FoxP3+ regulatory T cells, interleukin 17 and mast cells in chronic inflammatory periodontal disease.

BACKGROUND AND OBJECTIVE: T cells are known to play a pivotal role in periodontal disease; however, less is known about the T-helper subsets of regulatory T cells (Tregs) and Th17 cells. The aim of this study was to investigate the cell types expressing FoxP3 and interleukin (IL)-17A within periodontal disease tissues and to determine gene and protein expression profiles associated with periodontitis. MATERIAL AND METHODS: A total of 10 healthy/gingivitis and 10 chronic periodontitis tissues were investigated. Immunohistochemistry and immunofluorescence techniques were used to identify the FoxP3 and IL17-positive cells and to determine the cell types respectively. Gene expression was determined using semi-quantitative polymerase chain reaction array technology that allowed the analysis of 84 pathway-focused genes known to be associated with Tregs and Th17 cells. Transforming growth factor (TGF)-ß1, IL10 and IL17A protein levels were determined using enzyme-linked immunosorbent assay. RESULTS: Double immunofluorescence labeling revealed that all FoxP3+ cells were CD4+ , while IL17+ cells were neither CD4+ nor CD8+ but were tryptase+ , suggestive of mast cells. More FoxP3+ cells than IL17+ cells were found in all the tissues examined and overall there were few IL17+ cells. Statistically significant increases in gene expression were found for STAT5A, STAT3, SOCS1, TGFß1 and IL10 in the chronic periodontitis specimens predominantly infiltrated with B cells and plasma cells when compared with healthy/gingivitis specimens predominantly infiltrated with T cells. Protein analysis demonstrated higher levels of the TGFß1 and IL10 cytokines in periodontitis tissues and in B-cell and plasma cell predominant gingival tissues than in healthy/gingivitis tissues and T-cell predominant gingival tissues. IL17A gene and protein expression was not detected in any of the tissues. CONCLUSION: Based on the findings of this study, we suggest that the source of low levels of IL17A in periodontal tissues is mast cells not Th17 cells and that Tregs may have a more prominent role in the pathogenesis of periodontal disease than Th17 cells.

Preliminary findings from the Oranga Niho dental student outplacement project.

OBJECTIVES: To examine stakeholder perspectives of the Bachelor of Dental Surgery 2012-2013 clinical outplacement programme with Maori Oral Health Providers (MOHPs) and inform the programme's ongoing development. DESIGN: A mixed methods kaupapa Maori action research project. SETTING: Six North Island MOHPs and the University of Otago Faculty of Dentistry. PARTICIPANTS AND METHODS: Online questionnaires were used to conduct a pre- and post-outplacement survey of dental students and a twice-yearly survey of all MOHP-based clinical supervisors. Paper questionnaires were used to survey adult clients and caregivers of child clients that the students treated. Data were analysed descriptively and thematically. MAIN OUTCOME MEASURES: 68 (61%) of the 112 eligible students completed the pre- and post-outplacement questionnaires; 31 clinical supervisor questionnaire responses were received representing all six MOHPs; and 426 client and 130 caregiver questionnaire responses were received from five MOHPs. RESULTS: 79% of students felt well prepared for outplacement and 75% indicated that they would consider working for a MOHP in future. Of the clinical supervisors, 93% indicated that the students were adequately prepared for outplacement, and 68%, that they would recommend one or more students for employment. However, 58% associated the outplacements with decreased productivity. More than 97% of adult clients and caregivers of child clients were pleased with the care that the students provided. CONCLUSION: Recommendations for strengthening the outplacement programme included: increasing communication between the Faculty, MOHPs and students; addressing the financial cost of the programme to the MOHPs; and providing more support for clinical supervisors.

Forkhead box P3-positive regulatory T-cells and interleukin 17-positive T-helper 17 cells in chronic inflammatory periodontal disease.

BACKGROUND AND OBJECTIVE: The role of two recently identified and closely related T-helper cell subsets - regulatory T-cells [Tregs; forkhead box P3-positive (FOXP3(+) )] and Th17 cells [interleukin-17-positive (IL-17(+) )] - in periodontal disease is yet to be determined. Tregs are essential in maintaining peripheral tolerance and regulating the immune response. Th17 cells play a critical role in several autoimmune diseases, inflammation and host defence. The aim of this study was to determine the presence of FOXP3(+) Tregs and IL-17(+) cells, and their possible spatial interaction, in diseased periodontal tissues. MATERIAL AND METHODS: Twenty-nine archival tissues with nonspecific gingival inflammation were grouped based on the intensity (minimally or intensely inflamed) and nature (T-cell predominant or B- and plasma-cell predominant) of the inflammatory infiltrate. Using double-labelling immunohistochemistry, the concomitant presence of FOXP3(+) and IL-17(+) cells was determined and their spatial relationship was established. In addition, the proportions of FOXP3(+) and IL-17(+) cells were compared between the groups. RESULTS: Of the 29 gingival specimens investigated, 17 were intensely inflamed (≥ 1000 inflammatory cells per 0.12 mm(2) ) and 12 were minimally inflamed (≤ 600 cells per 0.12 mm(2) ). Based on the percentage of CD19(+) B-cells and plasma cells collectively and CD3(+) T-cells, gingival tissues were also grouped into B- and plasma-cell-predominant gingival tissues (n = 21; 50.7% total B- and plasma cells vs. 19.1% T cells; p < 0.001) and T-cell-predominant gingival tissues (n = 8; 61.0% T-cells vs. 15.2% B- and plasma cells; p = 0.007). More FOXP3(+) cells than IL-17(+) cells were observed in all archival gingival tissues examined. A trend towards an increased number of FOXP3(+) cells was observed for intensely inflamed gingival tissues (6.7%) and for B- and plasma-cell-predominant tissues (6.4%) compared with minimally inflamed gingival tissues (4.6%) and T-cell-predominant gingival tissues (4.5%). However, no statistically significant difference in the mean percentage of FOXP3(+) cells between the groups was observed. Interestingly, FOXP3(+) cells were significantly correlated with the B- and plasma-cell/T-cell ratio in B- and plasma-cell-predominant tissues (r = 0.713, p < 0.001). Overall, there were very few IL-17(+) cells (< 1%). All IL-17(+) cells identified in this study had an ovoid/plasmacytoid morphology and were larger in size compared with adjacent inflammatory cells. IL-17(+) and FOXP3(+) cells were not adjacent to each other in any of the areas examined, suggesting that FOXP3(+) Tregs do not directly interact with IL-17(+) cells in diseased gingival tissues. IL-17(+) /FOXP3(+) cells were not detected in the tissues examined. CONCLUSION: These results show that FOXP3(+) cells are more prominent than IL-17(+) cells in periodontal disease processes, which may suggest a predominant role for FOXP3(+) cells in periodontal disease. Further studies are required to characterize these cells more precisely and to understand, in more detail, their roles in the pathophysiology of periodontal disease.

Does performance in selection processes predict performance as a dental student?

OBJECTIVE: This study investigated associations between the performance of dental students in each of the three components of the selection procedure [academic average, Undergraduate Medicine and Health Sciences Admission Test (UMAT) and structured interview], socio-demographic characteristics and their academic success in an undergraduate dental surgery programme. MATERIALS AND METHODS: Longitudinal review of admissions data relating to students entering dental education at the University of Otago, New Zealand, between 2004 and 2009 was compared with academic performance throughout the dental programme. RESULTS AND DISCUSSION: After controlling for variables, pre-admission academic average, UMAT scores and interview performance did not predict performance as a dental student. Class place in second year, however, was a strong predictor of class place in final year. Multivariate analysis demonstrated that the best predictors of higher class placement in the final year were New Zealand European ethnicity and domestic (rather than international) student status. Other socio-demographic characteristics were not associated with performance. These interim findings provide a sound base for the ongoing study. CONCLUSION: The study found important socio-demographic differences in pre-admission test scores, but those scores did not predict performance in the dental programme, whether measured in second year or in final year.

Antigen recognition and presentation in periapical tissues: a role for TLR expressing cells?

Bacteria are the prime cause of periapical diseases and root canal microbiology is a well-researched area of endodontics. Antigen-presenting cells (APCs) are present in periapical lesions of endodontic origin and play a substantial role in recognizing, processing and presenting pathogenic antigens to the adaptive immune system such as an effective and long-lasting immune response is generated against the specific pathogens. Toll-like receptors (TLRs) are germ-line encoded pathogen recognition receptors (PRR) expressed by various APCs which induce their maturation, lead to gene transcription in the nucleus and the production of several pro- and anti-inflammatory cytokines. Thirteen TLRs have been discovered, 10 of which have been identified in humans so far. Preliminary studies of dental pulp tissue have demonstrated various cell types expressing different TLRs in response to commonly encountered microorganisms. However, there is little information available regarding the expression and function of the various TLRs in human periapical lesions. This review discusses the interactions of various APCs in periapical lesions and the possible roles of different TLRs and APCs in pulp/periapical pathogen recognition and presentation to the adaptive immune system in the initiation and sustaining of periapical diseases.

Toll-like receptor 2 expression in refractory periapical lesions.

AIM: To investigate the expression of TLR2 in refractory periapical lesions. METHODOLOGY: Refractory periapical lesion biopsies were histopathologically and clinically categorized into asymptomatic periapical granuloma (n=10), symptomatic periapical granuloma (n=10) or periapical cyst (n=10) and prepared for immunohistochemical staining using antibodies to TLR2, CD3 and CD19 or staining with methyl green pyronin. Sections were viewed under light microscopy and the presence or absence of the target cells was correlated with the histopathological and clinical data. Additionally, TLR2 expression was quantified by counting TLR(+) cells. RESULTS: Various mononuclear inflammatory cells in the bacteria-induced periapical lesions were reactive to TLR2 antibody, with many showing morphological similarities to lymphocytes and plasma cells. Lymphocytes were the most numerous cells in the inflammatory infiltrate. In refractory periapical granuloma, CD3(+) T cells were more numerous, whereas in periapical cysts, CD19(+) B cells were more numerous. There was a statistically significant (P<0.05) higher expression of TLR2 in symptomatic periapical granuloma than asymptomatic periapical granuloma or periapical cyst. CONCLUSION: The presence of TLR-expressing cells in periapical granulomas and cysts provides further evidence that periapical cysts are likely to be sustained by the immune system via reaction to bacterial antigens.

Self-reported occupational health of general dental practitioners.

BACKGROUND: Limited information is available regarding the occupational health status of dentists (particularly in New Zealand), although previous research suggests that stress, hand dermatoses and musculoskeletal symptoms are common. AIMS: To determine the occupational health status of New Zealand dentists. METHODS: A nationwide postal survey of a representative sample of 750 dentists. RESULTS: There was a response rate of 77%. Most dentists (71%) reported their general health as very good or excellent; 43% rated their physical fitness as excellent or very good and 64% were happy and interested in life. Workplace bullying had been experienced by 19% and was higher for female and employee dentists and 29% had experienced a violent or abusive incident at work. Almost half of the sample (47%) had experienced at least one dermatitis-type condition in the previous 12 months. The most commonly reported sites for musculoskeletal problems experienced in the previous year were the neck (59%), lower back (57%) and shoulders (45%). Women had a higher prevalence of several occupational health problems, but were more satisfied with their overall health than male dentists. CONCLUSIONS: The majority of dentists had good general health, but physical fitness levels were not ideal. The prevalence of hand dermatoses and musculoskeletal problems are high and impact significantly on dentists' daily lives. Interventions such as reducing weight and training in optimal working methods to reduce musculoskeletal problems and injuries (such as eye or needlestick incidents) might improve the health of this workforce but further research is required.

Job stressors of New Zealand dentists and their coping strategies.

BACKGROUND: Dentistry is understood to be a stressful profession. Although there has been recent research about stress and dentistry in the UK and the Netherlands, little is known about the job stressors and coping strategies of New Zealand dentists. AIM: To investigate job stressors and coping strategies among New Zealand dentists. METHODS: A nationwide postal survey of a representative sample of 700 dentists. RESULTS: The response rate was 65%. The most commonly reported stressors were treating difficult children (52%), constant time pressure (48%) and maintaining high levels of concentration (43%). The strategies most utilized for managing work-related stress included interactions with people (78%), sports (64%) and forgetting about work (59%). Dentists who had graduated overseas reported more sources of stress than New Zealand graduates. There were differences in the strategies used by male and female practitioners to manage stress. CONCLUSIONS: There is considerable variation in the number of stressors experienced by dentists. Overseas-qualified dentists appear to be under more stress than New Zealand-trained dentists and may need greater professional support. Dentists should be encouraged to make greater use of active coping strategies.

Second opinion oral pathology referrals in New Zealand.

Referral for a second opinion is an important aspect of pathology practice, which reduces the rate of diagnostic error and ensures consistency with diagnoses. The Oral Pathology Centre (OPC) is the only specialist oral diagnostic centre in New Zealand. OPC provides diagnostic services to dentists and dental specialists throughout New Zealand and acts as a referral centre for second opinions for oral pathology specimens that have been sent to anatomical pathologists. The aim of this study was to review second opinion referral cases sent to the OPC over a 15-year period and to assess the levels of concordance between the original and final diagnoses. The findings indicated that the majority of referred cases were odontogenic lesions, followed by connective tissue, epithelial and salivary lesions. The most prevalent diagnoses were ameloblastoma and keratocystic odontogenic tumour, followed by oral squamous cell carcinoma. Discordant diagnoses were recorded in 24% of cases. Diagnostic discrepancies were higher in odontogenic and salivary gland lesions, resulting in the change of diagnoses. Second opinion of oral pathology cases should be encouraged in view of the relative rarity of these lesions in general pathology laboratories and the rates of diagnostic discrepancy, particularly for odontogenic and salivary gland lesions.

VEGF and VEGFR2 in dentigerous cysts associated with impacted third molars.

The aims of this study were to determine the presence and distribution of vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor-2 (VEGFR2) in dentigerous cysts compared with normal dental follicles as a control tissue and to evaluate endothelial cells and proliferating cells as indicators of angiogenic activity in these tissues.Twenty specimens histologically diagnosed as dentigerous cysts and 20 dental follicle specimens were included. Immunohistochemistry (IHC) using anti-VEGF and anti-VEGFR2 antibodies stained for the growth factor and its receptor, while anti-CD34 and anti-CD146 antibodies were used to identify endothelial cells. Anti-proliferating cell nuclear antigen (PCNA) antibody detected proliferating cells within the specimens. Slides were examined microscopically and results evaluated using kappa statistics, negative binomial regression and ordinal logistic regression.The mean age for patients with dentigerous cysts was 23 years and they were more common in males. Proteins for VEGF, VEGFR2, PCNA, CD34, and CD146 were expressed in all dentigerous cysts and dental follicles. VEGF and VEGFR2 were expressed on several cell types within the tissues, however there was a significantly greater percentage of positive staining in dentigerous cysts compared with dental follicles (odds ratio = 31.24, p < 0.001). CD34(+), CD146(+), and PCNA(+) cells were observed in both dentigerous cysts and dental follicles but for all markers there were significantly more positive cells in dentigerous cysts (p < 0.001); this was especially evident in cases associated with inflammation. PCNA was seen in most endothelial cells lining small thin walled blood vessels suggesting endothelial proliferation. There was a high level of intra- and inter-examiner agreement (kappa 0.77 and 0.75, respectively).VEGF and VEGFR2 and angiogenic activity are present in dental follicles and dentigerous cysts and may contribute to local bone resorption for tooth eruption or the development and progression of dentigerous cysts.

p53 expression in oral precancer and cancer.

Expression of the p53 tumour suppressor gene is a frequent finding in human malignancies, including oral cancer, and it has been detected in some potentially malignant lesions. The results of the present project showed that 35 of the 41 (85 per cent) oral mucosal lesions with histological evidence of epithelial dysplasia expressed p53, but the presence or absence of p53 staining could not be used to predict the outcome of potentially malignant oral mucosal lesions.

Silver solder "tattoo," a novel form of oral pigmentation identified with the use of field emission scanning electron microscopy and electron dispersive spectrography.

OBJECTIVE: The aim of this study was to investigate the use of field emission scanning electron microscopy and electron dispersive spectrography (SEM-EDS) to identify silver solder "tattoo." STUDY DESIGN: SEM-EDS was used to analyze material present in the connective tissue of a patient who presented with bilateral pigmentation of the mandibular lingual gingiva adjacent to the first molars. No dental restorations were present. RESULTS: SEM-EDS analysis identified silver, with no evidence of tin, copper, or mercury. The patient was wearing an orthodontic appliance where brackets had been soldered to the archwire with silver solder. It is hypothesed that the solder underwent electrolytic corrosion with subsequent regrouping of silver ions in the submucosa leading to blue-gray discoloration. CONCLUSION: Spectrography proved to be a powerful diagnostic tool in identifying the metal within the oral mucosa. Attention is drawn to this newly described lesion, which should be included as a differential diagnosis for pigmented oral mucosal lesions.

An unusual presentation of oropharyngeal mucosal plasmacytosis related to toothpaste.

OBJECTIVE: We present the case of a 59-year-old Chinese patient with an unusual presentation of mucosal plasmacytosis involving the oropharynx, related to the use of toothpaste. METHOD: Case presentation and review of English medical literature involving mucosal plasmacytosis. RESULTS: Mucosal plasmacytosis is an uncommon disease process and has been associated with hypersensitivity reactions. Most cases involve the gingival mucosa, although there have been reports of cases involving other oral mucosal sites and the upper aerodigestive tract. Our case provides an example of oropharyngeal plasmacytosis related to toothpaste. A resolution of signs and symptoms followed withdrawal of the suspected allergens. CONCLUSION: Mucosal plasmacytosis is a benign inflammatory process that may appear to be more sinister on clinical examination. Skin patch testing is a useful adjunct in confirming the diagnosis.

Tongue lesions: what can it be?

In the course of the examination of a patient their tongue is easily visualized and with the use of gauze can be gently dried, held with gauze and stretched for inspection of all aspects. This can be followed by palpation of both the tongue and the floor of mouth. In this manner, any altered tissue is likely to be detected and, with or without further investigations, a diagnosis established. Appropriate management can then be undertaken. A wide range of conditions may involve the tongue and this article outlines some of these using a classification based on aetiology.

Undifferentiated connective tissue disease.

The purpose of this article is to bring to the attention of clinicians the diagnostic difficulties encountered in some patients with connective tissue syndromes. The relevant literature is reviewed, and a case of undifferentiated connective tissue disease in a patient with an oral mucosal disorder is described.

Histomorphometric analysis of epithelial changes in chemically induced oral mucosal carcinogenesis in rats.

Quantitative analysis of rat palatal mucosa after the carcinogen 4- nitroquinoline-1-oxide had been applied to the epithelium for varying periods of time showed that there was a significant increase in epithelial thickness, due largely to an increase in thickness of the basal compartment. This alteration was measurable before epithelial dysplasia could be recognised.

Squamous cell carcinoma of the oral mucosa: a review of 244 cases in Australia.

In an attempt to extend and update information relating to oral cancer in Australia and to provide a basis for international comparison a group of 244 patients suffering from oral cancer have been studied in detail. These patients were all diagnosed in one Oral Pathology Biopsy Service used almost exclusively by oral surgeons and dentists, and although this introduced bias into the sample it had the advantage of standardising documentation. The male: female ratio (1.3 : 1) of patients with oral cancer was lower than that previously reported in Australia, but the average age of patients (60 years) was comparable with many previous reports. The floor of the mouth was the most common site of cancer. There was a significant over-representation of tobacco and alcohol consumers amongst the patients, but a group of elderly females who had never used tobacco or alcohol, yet developed oral cancer, was identified. It was of particular interest that these elderly females had significantly lower haemoglobin and serum iron levels than a sex- and age-matched control group.

Actinobacillus actinomycetemcomitans infection in the oral cavity.

An abscess that developed following the extraction of periodontally involved teeth persisted after surgical drainage and ampicillin therapy. Subsequent culture of pus from this abscess gave a pure growth of Actinobacillus actinomycetemcomitans which was resistant to ampicillin. Surgical drainage and the use of appropriate antibiotic therapy cleared the infection. The identification of A. actinomycetemcomitans and the types of infection it causes are described. The probable mechanism of infection by the bacterium is discussed. A case that illustrates the importance of the microbiologic examination of pus from dental abscesses is reported.