Mineralization disorders with a broad range of etiological factors represent a huge challenge in dental diagnosis and therapy. Hypophosphatasia (HPP) belongs to the rare diseases affecting predominantly mineralized tissues, bones and teeth, and occurs due to mutations in the ALPL gene, which encodes tissue-nonspecific alkaline phosphatase (TNAP). Here we analyzed stem cells from bone marrow (BMSCs), dental pulp (DPSCs) and periodontal ligament (PDLSCs) in the absence and presence of efficient TNAP inhibitors. The differentiation capacity, expression of surface markers, and gene expression patterns of donor-matched dental cells were compared during this in vitro study. Differentiation assays showed efficient osteogenic but low adipogenic differentiation (aD) capacity of PDLSCs and DPSCs. TNAP inhibitor treatment completely abolished the mineralization process during osteogenic differentiation (oD). RNA-seq analysis in PDLSCs, comparing oD with and without TNAP inhibitor levamisole, showed clustered regulation of candidate molecular mechanisms that putatively impaired osteogenesis and mineralization, disequilibrated ECM production and turnover, and propagated inflammation. Combined alteration of cementum formation, mineralization, and elastic attachment of teeth to cementum via elastic fibers may explain dental key problems in HPP. Using this in vitro model of TNAP deficiency in DPSCs and PDLSCs, we provide novel putative target areas for research on molecular cues for specific dental problems in HPP.
Aim: Adjunctive systemic antibiotics may improve the outcome of mechanical periodontitis therapy. Systematic reviews revealed the lack of sufficient data and well-designed clinical trials about the efficacy of this adjunct to periodontal therapy. This protocol was designed to address demands and suggestions for further clinical trials made by recent EFP reviews. Materials and Methods: Investigation's design was a double-blind, placebo-controlled, multi-center randomized controlled trial over a 38-month period. We hypothesized that adjunctive antibiotic therapy significantly reduces (Δ50%) the occurrence of further attachment loss compared to subgingival debridement alone. The primary objective efficacy variable was the percentage of sites with a loss of clinical attachment ≥ 1.3 mm over the 24-month follow-up period. Key secondary variables were additional periodontal, microbiological and psychological parameters. Results: For eligibility 3261 patients were screened, 542 patients were recruited, and finally 406 patients completed the trial in December 2011 (power calculation revealed 350 completed cases). Conclusions: The experiences from this trial, considering demands and suggestions for clinical research from systematic reviews, showed that realization is possible. Those study designs are highly labor- and cost-intensive. Public funding will be even more important in the future to answer clinical questions on a generalizable population level. Keywords: Amoxicillin, metronidazole, RCT, periodontitis, trial design, scaling, clinically significant additional effect, multicenter study, placebo-controlled clinical study, oral health-related quality of life.
The aim of this follow-up study was, to compare the effects of mechanical periodontal therapy with or without adjunctive amoxicillin and metronidazole on the subgingival microbiome of smokers with periodontitis using 16S rDNA amplicon next generation sequencing. Fifty-four periodontitis patients that smoke received either non-surgical periodontal therapy with adjunctive amoxicillin and metronidazole (n = 27) or with placebos (n = 27). Subgingival plaque samples were taken before and two months after therapy. Bacterial genomic DNA was isolated and the V4 hypervariable region of the bacterial 16S rRNA genes was amplified. Up to 96 libraries were normalized and pooled for Illumina MiSeq paired-end sequencing with almost fully overlapping 250 base pairs reads. Exact ribosomal sequence variants (RSVs) were inferred with DADA2. Microbial diversity and changes on the genus and RSV level were analyzed with non-parametric tests and a negative binomial regression model, respectively. Before therapy, the demographic, clinical, and microbial parameters were not significantly different between the placebo and antibiotic groups. Two months after the therapy, clinical parameters improved and there was a significantly increased dissimilarity of microbiomes between the two groups. In the antibiotic group, there was a significant reduction of genera classified as Porphyromonas, Tannerella, and Treponema, and 22 other genera also decreased significantly, while Selenomonas, Capnocytophaga, Actinomycetes, and five other genera significantly increased. In the placebo group, however, there was not a significant decrease in periodontal pathogens after therapy and only five other genera decreased, while Veillonella and nine other genera increased. We conclude that in periodontitis patients who smoke, microbial shifts occurred two months after periodontal therapy with either antibiotics or placebo, but genera including periodontal pathogens decreased significantly only with adjunctive antibiotics.
In spite of the remarkable success of current preventive efforts, periodontitis remains one of the most prevalent diseases of mankind. The objective of this workshop was to review critical scientific evidence and develop recommendations to improve: (i) plaque control at the individual and population level (oral hygiene), (ii) control of risk factors, and (iii) delivery of preventive professional interventions.Discussions were informed by four systematic reviews covering aspects of professional mechanical plaque control, behavioural change interventions to improve self-performed oral hygiene and to control risk factors, and assessment of the risk profile of the individual patient. Recommendations were developed and graded using a modification of the GRADE system using evidence from the systematic reviews and expert opinion.Key messages included: (i) an appropriate periodontal diagnosis is needed before submission of individuals to professional preventive measures and determines the selection of the type of preventive care; (ii) preventive measures are not sufficient for treatment of periodontitis; (iii) repeated and individualized oral hygiene instruction and professional mechanical plaque (and calculus) removal are important components of preventive programs; (iv) behavioural interventions to improve individual oral hygiene need to set specific Goals, incorporate Planning and Self monitoring (GPS approach); (v) brief interventions for risk factor control are key components of primary and secondary periodontal prevention; (vi) the Ask, Advise, Refer (AAR) approach is the minimum standard to be used in dental settings for all subjects consuming tobacco; (vii) validated periodontal risk assessment tools stratify patients in terms of risk of disease progression and tooth loss.Consensus was reached on specific recommendations for the public, individual dental patients and oral health care professionals with regard to best action to improve efficacy of primary and secondary preventive measures. Some have implications for public health officials, payers and educators.
The aim was to determine the association between plaque and gingival inflammation reported by dietary interventions. Data of four clinical studies dealing with changed nutrition and gingival examination were reanalyzed with regard to gingival inflammation (GI), plaque (PI), and bleeding on probing (BOP). Dietary changes basically involved avoiding sugar, white flour and sweetened drinks and focusing on whole foods for 4 weeks. The control groups were to maintain their usual diet. All participants had to reduce their oral hygiene efforts. Linear regression models taking the clustering of the data due to several studies into account were applied. In total, data of 92 participants (control groups: 39, test-groups 53) were reanalyzed. While both groups showed a slight increase in dental plaque, only the test groups showed a significant decrease in inflammatory parameters: GI (mean value difference End-Baseline (Δ): −0.31 (±SD 0.36)) and BOP (Δ: −15.39% (±16.07)), both p < 0.001. In the control groups, there was a constant relation between PI and GI, while the experimental group showed a decreasing relationship in GI/PI (p = 0.016), and even an inverted relationship BOP/PI under a changed diet (p = 0.031). In conclusion, diet seems to be a determining factor how the gingiva reacts towards dental plaque.
The effect on local plaque formation of a varnish containing 1% chlorhexidine and 1% thymol (Cervitec®) was evaluated. Ten volunteers with clinically healthy oral conditions were asked to refrain from any kind of oral hygiene measures for three periods of three days. Undisturbed plaque formation was recorded during the first experimental period. At the beginning of the second period, the varnish was applied to six vestibular enamel surfaces and removed after 1 h. The third experimental period was initiated 12 weeks after varnish application to assess a potential long-term effect. During each period of plaque formation, samples were collected from the vestibular surfaces after 24 h (from teeth 15/25), after 48 h (from teeth 14/24) and after 72 h (from teeth 13/23), respectively, and evaluated for total microscopic bacterial counts (BC) and colony forming units (CFU). Microbial vitality was assessed by the plating efficiency [PE = (CFU/ BC) × 100] and directly by a vital fluorescence (VF) technique. VF of 48- and 72-hour plaque was significantly reduced after Cervitec application. An inhibitory effect by Cervitec could not be discerned 12 weeks after varnish treatment.
Summary The distribution of dermatan sulphate and chondroitin sulphate in human dental pulps has been assessed using monoclonal antibodies and immunoperoxidase localization techniques. The pulpal tissues were reacted with specific antibodies following pretreatment of the sections with chondroitinase ACII or chondroitinase ABC. Both the 4‐ and 6‐sulphated isomers of chondroitin sulphate were detected in the tissues studied. Very little derrmatan sulphate could be detected. These glycosaminoglycans appeared throughout the pulpal connective tissues with a particularly strong localization to the region adjacent to the odontoblastic and predentine layers. Such distribution strongly implicates chondroitin sulphate in the mineralization process of human dentine.
Objetivos: Estudiar la aplicabilidad clinica de la matriz dermica porcina en el tratamiento de los defectos tipo recesion.
Materiales y metodos: Se seleccionaron 28 recesiones gingivales en seis pacientes que se iban a someter a procedimientos de recubrimiento radicular utilizando una tecnica de tunel modificada y matriz dermica porcina. La profundidad y la anchura de la recesion gingival se utilizaron como parametros principales que se evaluaron al principio, asi como tras 6 y 12 meses postoperatorios. La anchura del tejido queratinizado se tomo como parametro secundario.
Resultados: A los 6 y 12 meses del postoperatorio, el recubrimiento radicular medio ascendia al 65,52% y 56,82%, respectivamente. Se consiguio un recubrimiento radicular completo en el 42,86% de los defectos tratados.
Conclusiones: La matriz dermica porcina puede utilizarse potencialmente como material de sustitucion del tejido autologo. Sin embargo, solo se consiguio un recubrimiento radicular completo en menos de la mitad de los defectos estudiados.
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