Differential Response of Oral Mucosal and Gingival Cells to Corynebacterium durum, Streptococcus sanguinis, and Porphyromonas gingivalis Multispecies Biofilms.

Polymicrobial interactions with oral mucosal surfaces determine the health status of the host. While a homeostatic balance provides protection from oral disease, a dysbiotic polymicrobial community promotes tissue destruction and chronic oral diseases. How polymicrobial communities transition from a homeostatic to a dysbiotic state is an understudied process. Thus, we were interested to investigate this ecological transition by focusing on biofilm communities containing high abundance commensal species and low abundance pathobionts to characterize the host-microbiome interactions occurring during oral health. To this end, a multispecies biofilm model was examined using the commensal species Corynebacterium durum and Streptococcus sanguinis and the pathobiont Porphyromonas gingivalis. We compared how both single and multispecies biofilms interact with different oral mucosal and gingival cell types, including the well-studied oral keratinocyte cell lines OKF4/TERT-1and hTERT TIGKs as well as human primary periodontal ligament cells. While single species biofilms of C. durum, S. sanguinis, and P. gingivalis are all characterized by unique cytokine responses for each species, multispecies biofilms elicited a response resembling S. sanguinis single species biofilms. One notable exception is the influence of P. gingivalis upon TNF-α and Gro-α production in hTERT TIGKs cells, which was not affected by the presence of other species. This study is also the first to examine the host response to C. durum. Interestingly, C. durum yielded no notable inflammatory responses from any of the tested host cells, suggesting it functions as a true commensal species. Conversely, S. sanguinis was able to induce expression and secretion of the proinflammatory cytokines IL-6 and IL-8, demonstrating a much greater inflammatory potential, despite being health associated. Our study also demonstrates the variability of host cell responses between different cell lines, highlighting the importance of developing relevant in vitro models to study oral microbiome-host interactions.

A Randomized Split-Mouth Clinical Trial on Effectiveness of Amnion-Chorion Membranes in Alveolar Ridge Preservation: A Clinical, Radiologic, and Morphometric Study.

PURPOSE: Recent case reports suggest that amnion-chorion membranes (ACM) and dense polytetrafluoroethylene membranes (dPTFE) can be left exposed during ridge preservation. The aim of this study was to compare the effectiveness of these membranes in ridge preservation, particularly when they are intentionally left exposed. MATERIALS AND METHODS: A split-mouth, single-blind, randomized trial design was used to compare treatments with the two membranes in 22 nonmolar sites on the same arch. Ridge dimensions were recorded clinically and with cone beam computed tomography prior to and 3 months after ridge preservation. Postoperative discomfort was recorded with Visual Analog Scale (VAS) forms. Mixed­model analysis of variance was used to test significance. RESULTS: Clinical and radiographic ridge dimensions were not significantly different between the two treatments. ACM sites had significantly more osteoid and higher bone volume density but significantly less graft particles and bone surface density compared with dPTFE. Mineralized bone area and soft tissue area were not significantly different between the two treatments. ACM sites had significantly lower postoperative VAS scores compared with dPTFE. CONCLUSION: Intentionally exposed ACM is equally effective in ridge preservation compared with dPTFE. Additionally, ACM use may aid in reducing postoperative VAS scores, and potentially result in better quality of bone available for implant placement, as evidenced by improved histomorphometric measures.

Cross-Sectional Analysis of National Dental Residency Match Data.

The Dental Residency Match (DRM) program provides an ethical and unbiased selection process for applicants to postdoctoral dental programs, based on mutual interests of applicants and programs. The aims of this study were to conduct a descriptive analysis of DRM metrics for the years 2008 to 2015 and to test the hypothesis that there was a difference in number of ranks submitted between programs that filled all their offered positions and those that did not. DRM metrics data from years 2008 to 2015 were obtained from the National Matching Service. Trend analyses and panel data assessments were made. Six types of postdoctoral dental programs (GPR, AEGD, oral and maxillofacial surgery, pediatric dentistry, orthodontics, and dental anesthesiology) participate in the DRM program. The results showed that the number of programs participating and number of residency positions offered increased over the study period. The programs that filled all their positions ranked more applicants than the programs that did not fill their positions (p<0.05). The number of acceptable applicants increased over the study period for all programs except those in dental anesthesiology. These results suggest that participation in DRM is increasing, most programs are able to fill their positions with acceptable applicants, and programs seeking to fill all their positions need to submit a large number of ranks.

Impact of Periapical Abscess on Infectious Complications in Patients Undergoing Extracorporeal Circulation Auxiliary to Open-Heart Surgical Procedures.

OBJECTIVE: Extracorporeal circulation auxiliary to open-heart surgeries (ECAOHS) may exert nonphysiological stresses on periapical abscessed tissues leading to hematogenous spread of microbes. The aim of this report was to estimate risk of postoperative infectious complications in patients with periapical abscesses and undergoing ECAOHS. METHODS: A retrospective analysis of Nationwide Inpatient Sample (years 2009 and 2010) was conducted. All patients (aged 19 to 65 years) who underwent ECAOHS were selected. International Classification of Diseases-9-Clinical Modification codes were used to identify the presence of periapical abscess and infectious complications. Multivariable logistic regression models were used to examine the associations between the presence of periapical abscess and occurrence of infectious complications. RESULTS: A total of 265,235 patients underwent an ECAOH procedure. Of these, 431 patients had a periapical abscess. Septicemia developed in 16% of those with periapical abscess (compared with 4.2% in those without periapical abscess). Those with periapical abscess had higher rates of any of the infectious complications when compared with those without periapical abscess (30.2% vs 11.6%, respectively). After adjustment for multiple confounders, those with periapical abscess were associated with higher odds for developing septicemia (odds ratio = 2.51, 95% confidence interval = 1.06-5.91, P = .04) and any of the infectious complications (odds ratio = 2.23, 95% confidence interval = 1.08-4.59, P = .03) when compared with those who did not have periapical abscess. CONCLUSIONS: Those with periapical abscess are associated with higher odds for infectious complications when compared with those without periapical abscess.

A Risk of Bias Assessment of Randomized Controlled Trials (RCTs) on Periodontal Regeneration Published in 2013.

OBJECTIVE: The objective of this assessment is to evaluate the degree of risk of bias in randomized controlled trials published in 2013 and focusing on periodontal regeneration. METHODS: Three reviewers searched and selected the trials based on pre-defined inclusion criteria. Predictor variables [number of authors, primary objective of the study, biomaterial employed, follow-up time periods, split mouth study (yes/no), journal, year of publication, country, scale (single/multi-center) and nature of funding] were extracted and risk of bias assessment using Cochrane risk of bias tool were performed independently by the three reviewers. RESULTS: Seventeen RCTs were included in this assessment. The risk of bias in RCTs published in 2013 with a focus in periodontal regeneration varied significantly with only in less than 30% of the included trials, the overall risk of bias was found to be low, while 41% of trials were designated to have a higher degree of bias. Specifically, when looking at the domains assessed, 70% of the included trials reported an accepted method of sequence generation, blinding (whenever possible), completeness of outcome data or avoided selective outcome reporting. Meanwhile, only 47% of the included trials reported some form of allocation concealment. CONCLUSION: In this assessment, of the included 17 trials, slightly more than 40% of them had a high risk of bias, underscoring the importance of careful appraisal of trials before implementing the study interventions in clinical practice and the need for more detailed analyses.

Poor Oral Health Linked with Increased Risk of Infectious Complications in Adults with Leukemia.

OBJECTIVE: The objective of this study is to examine the impact of the presence of gingivitis/periodontitis on the occurrence of infectious complications (including septicemia, bacterial infections, and mycoses) in hospitalized leukemic adults in the United States. METHODS: A retrospective analysis of the Nationwide Inpatient Sample (NIS) for the years 2004-2010 was performed. All hospitalized leukemic patients aged 18 to 65 years were selected. The association between occurrence of gingivitis/periodontitis and infectious complications was examined by multivariable logistic regression models. A total of 135,692 hospitalizations were due to leukemias during the study period. Among these, gingivitis/periodontitis was present in 0.6%. Septicemia occurred in 27.8% of those who had gingivitis/periodontitis (compared to 19.6% in those without gingivitis/periodontitis), bacterial infections occurred in 19.5% of those who had gingivitis/periodontitis (compared to 10.1% in those without gingivitis/periodontitis), and mycoses occurred in 20.7% of those who had gingivitis/periodontitis (compared to 10.7% in those without gingivitis/periodontitis). Patients who had gingivitis/periodontitis were associated with significantly higher odds for septicemia (OR = 1.58, 95% CI = 1.14-2.19, p = 0.01), bacterial infections (OR = 2.15, 95% CI = 1.51-3.07, p<0.01), mycoses (OR = 2.16, 95% CI = 1.43-3.28, p<0.01), or any infectious complication (OR = 2.15, 95% CI = 1.63-2.84, p<0.01) when compared to their counterparts following adjustment for multiple patient and hospital-level confounding factors. CONCLUSIONS: Poor oral health (as defined by the presence of gingivitis/periodontitis) is an independent predictor of increased risk of infectious complications in hospitalized leukemic adults in the United States.

Designing a safety checklist for dental implant placement: a Delphi study.

BACKGROUND: Complications during and after dental implant placement can be a hindrance to successful treatment. Checklists are emerging as useful tools in error reduction in various fields. The authors selected a Delphi panel to explore the appropriate clinical practices involved in implant placement, with the objective of formulating a safety checklist that would aid in reducing errors. METHODS: The authors administered a Delphi method survey to an expert panel of 24 board-certified periodontists to determine if consensus existed regarding the critical steps involved in implant placement. They defined consensus as 90 percent agreement among participants. Using the Delphi data, the authors designed a safety checklist for implant placement. RESULTS: The panelists generated 20 consensus statements regarding essential steps in implant placement. The authors divided the statements into preoperative, intraoperative and postoperative phases. To determine the rationale for consensus decisions, the authors conducted a thematic qualitative analysis of responses to all open-ended questionnaire items, asking panel members how or why a particular procedure was performed. CONCLUSION: The panelists reached a consensus regarding the steps they considered critical in implant placement. Further research is needed to assess the acceptance and effectiveness of this type of checklist in a clinical setting. Practical Implications. The authors developed a checklist that may be useful in reducing errors in placement of dental implants. If effective, this checklist ultimately will aid in minimizing risk and increasing implant success rates, especially for inexperienced practitioners, dental students, surgical residents and dental implant trainees (that is, dentists undergoing training to place implants through continuing education courses).

Consensus training: an effective tool to minimize variations in periodontal diagnosis and treatment planning among dental faculty and students.

Considerable disagreements and variations exist in diagnosis and treatment planning of periodontal disease. Achieving high interrater periodontal diagnosis can prove challenging. The objectives of this study were to measure variations in periodontal diagnosis and treatment planning among predoctoral periodontics faculty members after consensus training and to compare such variation with those identified in third- and fourth-year dental students. Nine electronically stored case vignettes and survey instruments were made available to eighteen faculty members and twenty dental students under standardized conditions. A chi-square test was used to compare responses between groups, and multirater kappa tests were used to evaluate interrater agreement/reliability. Of the nine cases, only one differed between groups significantly in terms of treatment. Also, third-year students differed from fourth-year students on the diagnosis of aggressive periodontitis versus chronic periodontitis. Most respondents were able to distinguish clearly among diagnoses of chronic periodontitis, aggressive periodontitis, and gingivitis. This study established a baseline assessment of the current status of consensus after training. We will reassess variations after addressing the specific challenges identified. Programs designed and implemented to help decrease the variation in periodontal diagnosis and treatment planning among faculty members may ultimately translate into better agreement and better standardization of dental instruction.

Differential expression of TLR-2 and TLR-4 in the epithelial cells in oral lichen planus.

OBJECTIVE: Oral lichen planus (OLP) is a chronic inflammatory condition of the mucosa mediated by a complex signalling network between the keratinocytes and the sub-epithelial lymphocytes. Since OLP occurs in constantly renewing epithelium continuously exposed to commensals, we hypothesised that the epithelial cell microflora interactions may mediate the persistent inflammation. By virtue of their ability to respond to most oral commensal microorganisms, the toll like receptor-2 (TLR-2) and TLR-4 are the most widely investigated receptors in oral diseases. The overall objective of this study was to investigate the role of TLR-2 and TLR-4 in OLP. DESIGN: Systemically healthy OLP and control subjects were recruited after obtaining the institutional review board approval. Expression of TLR-2 and TLR-4 proteins and transcripts in the tissue epithelium and in the epithelial cells isolated from saliva were determined by immunohistochemistry and quantitative real-time polymerase chain reaction respectively. RESULTS: The tissue epithelium and the salivary epithelial cells expressed reduced TLR-2 and increased TLR-4 proteins and transcripts in OLP. The salivary epithelial cells from OLP subjects secreted elevated IL-12. However, upon stimulation with bacterial lipopolysaccharide the epithelial cells from OLP exhibited a mixed Th1 (IL-12) and Th2 (IL-4) response. Presence of dexamethasone significantly reduced inflammatory cytokines in the in vitro stimulated cultures of salivary epithelial cells from OLP subjects. CONCLUSION: Collectively, our data support a critical role for the host-microbial interactions in the OLP pathogenesis. The potential use of exfoliated oral epithelial cells in saliva for functional analysis exponentially increases its value as biological specimen for clinical research.