The neutralising and stimulatory effects of antimicrobial peptide LL-37 in human gingival fibroblasts.

OBJECTIVES: To investigate the effects of LL-37, a broad spectrum antimicrobial peptide expressed in periodontal tissues, on human gingival fibroblast responsiveness to microbial challenge and to explore the direct effects of LL-37 on human gingival fibroblasts. DESIGN: The effect of LL-37 on bacterial lipopolysaccharide-induced expression of Interleukin (IL-6) and chemokine C-X-C motif ligand (CXCL) 8 was determined by enzyme linked immunosorbent assay (ELISA). LL-37's influence on bacterial lipopolysaccharide-induced IκBα degradation was investigated by western blot. DNA microarray analysis initially determined the direct effects of LL-37 on gene expression, these findings were subsequently confirmed by quantitative polymerase chain reaction and ELISA analysis of selected genes. RESULTS: Bacterial lipopolysaccharide-induced IL-6 and CXCL8 production by human gingival fibroblasts was significantly reduced in the presence of LL-37 at concentrations in the range of 1-10 µg/ml. LL-37 led to a reduction in lipopolysaccharide-induced IκBα degradation by Escherichia coli lipopolysaccharide and Porphyromonas gingivalis lipopolysaccharide (10 µg/ml). LL-37 (50 µg/ml) significantly altered the gene expression of 367 genes in human gingival fibroblasts by at least 2-fold. CXCL1, CXCL2, CXCL3, Interleukin-24 (IL-24), CXCL8, Chemokine (C-C motif) Ligand 2, and Suppressor of Cytokine Signalling 3 mRNA were significantly upregulated by LL-37. LL-37 also significantly stimulated expression of CXCL8, hepatocyte growth factor and CXCL1 at the protein level. CONCLUSION: LL-37 plays an important regulatory role in the immunomodulatory activity of gingival fibroblasts by inhibiting lipopolysaccharide -induced expression of inflammatory cytokines and directly stimulating the expression of an array of bioactive molecules involved in inflammation and repair.

Efficacy of direct pulp capping for management of cariously exposed pulps in permanent teeth: a systematic review and meta-analysis.

BACKGROUND: The outcome of vital pulp treatment after carious pulp exposure is multifactorial and related to the procedure, biomaterial and pre-operative pulpal diagnosis. OBJECTIVES: To conduct a systematic review and meta-analysis determining the outcome of direct pulp capping (DPC) in mature permanent teeth with a cariously exposed pulp and a clinical diagnosis of reversible pulpitis, and ascertain whether the capping material influences the outcome. METHODS: Sources: MEDLINE Ovid-SP, Cochrane Central Register of Controlled Trials (CENTRAL), International Clinical Trials Registry Platform (ICTRP), ClinicalTrials.gov, Embase and Web of Science until April 2020. Inclusion: Prospective, retrospective cohort studies and randomized trials investigating DPC outcome or comparing different capping materials after carious pulp exposure. Exclusion: Primary teeth, mechanical, traumatic or not specified pulp exposure, teeth with irreversible pulpitis or no pulpal diagnosis. Risk of bias assessed using Cochrane and modified Downs and Black quality assessment checklist. Meta-analysis on combined clinical/radiographic outcome was performed using a random effect model. Success was defined as absence of signs and symptoms of irreversible pulpitis, apical periodontitis or loss of pulp vitality. RESULTS: Quality assessment highlighted four non-randomized studies to be of fair and five of poor quality. Four randomized trials had a high risk of bias. The pooled success rate differed based on material and follow-up. Calcium hydroxide success rate was 74% at 6-months, 65% at 1-year, 59% at 2-3 years and 56% at 4-5 years. Mineral trioxide aggregate (MTA) success was 91%, 86%, 84% and 81% at the same time points. Biodentine success was 96% at 6-months, 86% at 1 year and 86% at 2-3 years. The meta-analysis revealed MTA had better success than calcium hydroxide at 1-year (OR 2.66, 95% CI; 1.46- 4.84, P = 0.001) and 2- to 3-year follow-up (OR 2.21, 95% CI; 1.42-3.44, P = 0.0004). There was no difference between MTA and Biodentine. DISCUSSION: These results were based on poor methodological quality studies. The effect size for of MTA vs Ca(OH)2, although modest, was consistent with narrow CI. CONCLUSIONS: Low-quality evidence suggests a high success rate for direct pulp capping in teeth with cariously exposed pulps with better long-term outcomes for MTA and Biodentine compared with calcium hydroxide.

An audit on technical quality of root fillings performed by undergraduate students.

AIM: To evaluate radiographically the technical quality of root fillings performed by undergraduate dental students and to assess whether students were exposed to an appropriate endodontic case mix during their clinical training. METHODOLOGY: A retrospective audit was undertaken evaluating the clinical records of patients who underwent endodontic procedures during the period from September 2015 to June 2016 in the Dental School at Queen's University Belfast, UK. Two final-year dental students were trained and calibrated to evaluate postoperative intra-oral periapical radiographs of completed root canal treatments using specific assessment criteria. Data were presented as frequencies, percentage and mean ± standard deviation (SD). Comparisons of treatment outcomes between groups (posterior and anterior teeth) were calculated using Fisher's exact test, and the level of significance was set at P < 0.05. Intra- and interexaminer reproducibility was assessed by Kappa statistics. RESULTS: A total of 222 teeth and 381 canals were assessed, and of those, 253 (66%) of the root fillings were found to be acceptable in all the assessment parameters, namely taper, length and lateral adaptation of the root filling. Subanalysis of individual root filling parameters revealed that 372 canals (97%) exhibited good taper, and 275 canals (72%) were considered to be of an appropriate length, with 89 canals (23%) found to be underfilled and 17 canals (5%) overfilled. Overall 346 (91%) of canals had good lateral condensation. Students treated both single and multirooted teeth, and there was no significant association between tooth type and the quality of root filling provided (P > 0.05). CONCLUSIONS: In the majority of the teeth treated by undergraduate students at Queen's University Belfast, the technical quality of the root filling was acceptable and students were exposed to an appropriate case mix for endodontic training.

Interferon-γ stimulates CD14, TLR2 and TLR4 mRNA expression in gingival fibroblasts increasing responsiveness to bacterial challenge.

OBJECTIVE: To investigate the potential effects of IFN-03A5 on the responsiveness of human gingival fibroblasts to bacterial challenge. DESIGN: mRNA and protein expression of CD14, TLR2 and TLR4 in human gingival fibroblasts was detected by quantitative polymerase chain reaction (Q-PCR) and flow cytometry. The effect of preincubation with IFN-03A5 on subsequent bacterial LPS-induced expression of IL-6 and IL-8 by gingival fibroblasts was determined by ELISA. Bacterial LPS-induced IκBα degradation in human gingival fibroblasts was investigated by western blot. RESULTS: Human gingival fibroblasts express CD14, TLR2 and TLR4 mRNAs. IFN-03A5, but not IL-103B2, induced mRNA expression of all three receptors and the expression of membrane bound CD14 protein. Pre-incubation of fibroblasts with IFN-03A5 and subsequent stimulation with Escherichia coli LPS or Porphyromonas gingivalis LPS led to increased production of IL-6 and IL-8. LPS-induced pro-inflammatory cytokine production was abrogated by a blocking antibody to CD14. Both E. coli LPS and P. gingivalis LPS induced IκBα degradation in human gingival fibroblasts. CONCLUSION: Our data indicate that IFN-03A5 primes human gingival fibroblasts, through the upregulation of CD14 expression, which results in increased responsiveness to bacterial LPS challenge, as determined by pro-inflammatory cytokine production.