A review on the prevention of inflammatory periimplant diseases

Background: An impressive number of dental implants are inserted worldwide. Evolution in dental implants and simplification of surgical techniques allowed a significant increase in the number of dentists involved in implant surgery. Most of them are general dentists, are not always sufficiently formed and experienced, frequently use low-quality implants, do not adopt the proper patient selective criteria, do not adequately monitor and maintain the inserted implants, and do not report their own statistics to the dental community. Consequently, the incidence of inflammatory periimplant diseases (IPDs) has progressively increased to values significantly higher than those previously indicated by the scientific literature. Materials and Methods: Two main literature searches were undertaken in October 2018 in the PubMed Website database. Only articles written in English and published from 2008 onward were considered; 'Clinical Trial,' 'Meta analysis,' 'Observational study,' 'Review,' and 'Validation study' were selected as article type filters. The following keywords were used in the searches: 'Peri implantitis prevention' and 'Dental implant failure prevention.'Results: Preventive measures are analyzed according to the different factors that can favor the occurrence of an infection. The factors are divided into (i) implant dependent, (ii) patient dependent, and (iii) surgeon dependent. Conclusions: Scientific and clinical data confirm that when materials are selected with care, patients are carefully evaluated for factors of risk and attitude to adhere to the necessary maintenance program, and operative protocols and maintenance programs are respected dental implants can be attractive and effective tools for oral rehabilitation. Nevertheless, dentists and patients should have greater awareness that in many cases the decision to utilize dental implants cannot be taken lightly

ADHESION AND BIOFILM FORMATION BY PERIODONTOPATHOGENIC BACTERIA ON DIFFERENT COMMERCIAL BRACKETS

Objective. To compare early bacterial adhesion and biofilm formation in vitro by common and uncommon periodontal pathogens on a variety of commercial brackets. Matherials and Methods Adhesion and biofilm formation in vitro of 4 bacterial strains on 15 different commercial brackets, in standard culture mediums complemented or not with either serum or human saliva was evaluated by quantitative real time PCR after extraction of bacterial DNA. Results. Materials significantly influenced bacterial adhesiveness in a species specific way. Titanium and gold brackets constantly yielded the lowest values with all tested bacteria and in all tested conditions. Bracket materials and medium of growth significantly influenced biofilm formation. Conclusions. Materials and environmental conditions significantly influence biofilm formation by periodontal pathogens at the surface of brackets. Whenever possible brackets should be kept far from the gingival margin and if this is not possible, brackets made of gold, titanium, and ceramic should be preferentially used

Inflammatory periimplant diseases and the periodontal connection question

Implant therapy has become a widespread reality in modern dentistry. Nevertheless, dental implants can fail due to different causes, among which inflammatory peri-implant diseases (IPDs) are a major challenge, with prevalences that are much higher than previously believed. Specific searches were undertaken for each question raised between October and November 2017, in the PubMed website database (US National Library of Medicine, National Institutes of Health; Bethesda, Maryland, United States). Only articles written in English and published from 2007 onward were considered initially. The following keywords were used in the searches periimplantitis (PI), periimplant mucositis (PM), dental implant failure, periimplant microbiota, periodontal microbiota, implant failure (no temporal limit), and foreign body reaction (no temporal limit). The selection process resulted in the selection of 239 articles that were analyzed in detail in elaborating this review. The reference list was limited to the 47 most relevant articles due to editorial limits of this Journal. Intrinsic differences between natural teeth and dental implants are able to give rise to inflammatory diseases that share only minor and scarcely relevant characters, and would consequently deserve different and specifically designed instruments and strategies, for both diagnosis and therapy

ADHESION AND BIOFILM FORMATION BY ORAL STREPTOCOCCI ON DIFFERENT COMMERCIAL BRACKETS

Objective. To compare early bacterial adhesion and biofilm formation in vitro by different oral streptococci on a variety of commercial brackets Materials and Methods. Adhesion and biofilm formation in vitro of 6 Streptococcus spp. on 15 different commercial brackets, in standard culture medium and in human saliva was evaluated by the MTT reduction assay. Results. Significant differences were evidenced in both early adhesion and biofilm formation among the studied brackets and between the two conditions of growth. Gold brackets resulted less prone to colonization, while composites brackets were the most prone ones. The rates of growth of the different tested species on the different tested materials were significantly different. Conclusions. The adopted experimental plan, dissecting the two phases of plaque formation on different brackets in different conditions, showed that composite brackets are more susceptible to adhesion and colonization by streptococci, while the remaining tested brackets do not show differences that could be clinically relevant. Data suggest that different personal behaviors affecting the oral environment could significantly affect colonization of brackets by cariogenic bacteria

Harnessing the power of biologic agents on the oral microbiota: a way to promote oral and systemic health?

During the long history of their evolution, higher organisms, including mammals, have learnt to take great advantage from living in close contact with selected populations of microbes.1 By living in close contact, animals and microbes underwent a progressive and mutual co-evolutive process that is believed to be a major driving force in the development of adaptive immunity of vertebrates.2 As a result of this co-evolutive process, humans and other animals are characterized by their own unique microbiomes, each consisting of many hundred species of viruses, bacteria, archaea, fungi, and protozoa, unevenly distributed to colonize the different accessible regions of the body.3 The human microbiome is believed to account for 1-3% of body weight and to comprise more than 100 trillion cells.4 The microbiota is involved in complex host-microbe and microbe-microbe interactions, thus modulating nutrient acquisition, adjusting immune system development and general homeostasis (via epigenetic modifications of host genes5), and playing the role of protective barrier to pathogens.4 When a microbiota undergoes qualitative and quantitative changes with regard to distribution in a site and metabolic activity, this condition is defined dysbiosis and is expected to be associated with local and/ or distant pathologic signs.6 Bacterial products released by a dysbiotic microbiota interact with homeostatic mechanisms of the human host and cooperate to the pathogenesis of major human diseases, including diabetes mellitus, inflammatory bowel syndrome, atherosclerosis, obesity, liver disease, and cancer.4,7 he oral microbiota is the second more abundant and one of the most diverse and unique microbial communities in the human body.8 Although many of the most relevant oral and dental diseases, including caries, periodontal and peri-implant diseases, have been long recognized as of microbial origin, only recently the application of culture independent molecular methods using 16S rRNA gene comparative analyzes enabled us to understand that they are caused by dysbiosis rather than by the action of specific pathogens.9-11 The effects of oral dysbiosis are not limited to oral tissues: periodontal diseases, for example, are among the most common human diseases and their associations with diabetes, cardiovascular disease, metabolic disease and obesity, rheumatoid arthritis, certain cancers, respiratory diseases, and cognitive disorders is now supported by increasing evidence.12 Recent molecular investigations showed that some potentially pathogenic oral bacteria (named pathobionts), as for example Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum, colonize in low numbers the oral cavity of healthy individuals, without alerting sentinel systems of mucosal defences.13,14 Conditions able to disrupt the eubiotic equilibrium promote the overgrowth of pathobionts, which suddenly become pathogens (with support from commensal

The molecular class C acid phosphatase of Chryseobacterium meningosepticum (OlpA) is a broad-spectrum nucleotidase with preferential activity on 5'-nucleotides

The olpA gene of Chryseobacterium meningosepticum, encoding a molecular class C phosphatase, was cloned and expressed in Escherichia coli. The gene encodes a 29-kDa polypeptide containing an amino-terminal signal peptide typical of bacterial membrane lipoproteins. Expression in E. coli results in a functional product that mostly partitions in the outer membrane. A secreted soluble OlpA derivative (sOlpA) lacking the N-terminal cysteine residue for lipid anchoring was produced in E. coli and purified by means of two steps of ion exchange chromatography. Analysis of the kinetic parameters of sOlpA with several organic phosphoesters revealed that the enzyme was able to efficiently hydrolyze nucleotide monophosphates, with a strong preference for 5'-nucleotides and for 3'-AMP. The enzyme was also able to hydrolyze sugar phosphates and beta-glycerol phosphate, although with a lower efficiency, whereas it was apparently inactive against nucleotide di- and triphosphates, diesters, and phytate. OlpA, therefore, can be considered a broad-spectrum nucleotidase with preference for 5'-nucleotides. Its functional behaviour exhibits differences from that of the Haemophilus influenzae OMP P4 lipoprotein, revealing functional heterogeneity among phosphatases of molecular class C

Anthropometric comparison between young Estonian and Chinese swimmers

Due to the progressive lowering of the age of peak performance among swimmers, it became important to better understand the factors influencing performance in prepuberal boys and girls. Aim of this study is to compare two different racial/ethnic groups of young swimmers, one from Nord-Europe, Estonia (Tartuma Region), and the other from China (Shanghai District) in order to assess existing differences in respect to body dimension, body fat, technical parameters of swimming performance and maximum lactate production. 26 Estonian and 7 Chinese female and 25 Estonian and 10 Chinese male, from two swimming schools, took part in the study. Anthropometric parameters were measured in accord with ISAK guidelines. BMI, Stroke Index, Stroke Length, mean velocity on a 200 m freestyle all out, and blood lactate after three minutes were measured. Significant differences exist in anthropometry between Nord-European and Asian young swimmers. These differences are more pronounced in female, with higher fat tissue in Nordic girls. Leg lengths are different between Chinese and Estonian girls having the Estonian longer legs. Hands lengths are different both in male and in female subjects. Being the Chinese groups of higher level of performance (higher mean velocity in the 200 m freestyle, such differences seems not to be as major determinants of the performance, also if they are often indicated as determinants of buoyancy and stroke efficiency

Probiotic streptococcus salivarius reduces symptoms of denture stomatitis and oral colonization by Candida Albicans

Denture stomatitis (DS) is an inflammatory status of oral mucosae frequently observed in denture wearers, and mainly associated with oral overgrowth of Candida albicans. DS is the cause of multiple visits to the dental office and is thought to enhance the risk of systemic infections. The treatment of DS mainly relies upon improvement of oral hygiene measures and prescription of topical or systemic antifungal agents, and disinfectants that, although effective, are not without drawbacks. Since, in recent years, some probiotics were investigated as a means to contrast oral colonization by Candida spp., this study was designed to preliminarily evaluate the effects of probiotic strain Streptococcus salivarius K12, in subjects affected by DS, and the duration of these effects. Fifty adult denture wearers affected by DS were enrolled and randomly divided into two groups: the experimental group was instructed to perform careful oral and denture hygiene and to assume the probiotic preparation for 30 days; the control group received only oral hygiene instructions. Patients were evaluated for signs of DS at the beginning of the study, at the end of treatment and 30 days later. Microbiological samples were obtained at the beginning of the study and at the end of treatment to quantify Candida albicans cells. Experimental treatment reduced clinical signs and symptoms of DS and the count of C. albicans. The clinical effects of experimental treatment were still evident after 30 days, suggesting that administration of probiotic strain Streptococcus salivarius K12 could be a promising approach in the treatment of DS

Migraine and cluster headache show impaired neurosteroids patterns

Background: Perturbation of neuronal excitability contributes to migraine. Neurosteroids modulate the activity of γ-aminobutyric acid A and N-methyl-d-aspartate receptors, and might be involved in the pathogenesis of migraine. Here, we measured plasma levels of four neurosteroids, i.e., allopregnanolone, epiallopregnanolone, dehydroepiandrosterone and deydroepiandrosterone sulfate, in patients affected by episodic migraine, chronic migraine, or cluster headache. Methods: Nineteen female patients affected by episodic migraine, 51 female patients affected by chronic migraine, and 18 male patients affected by cluster headache were recruited to the study. Sex- and age-matched healthy control subjects (31 females and 16 males) were also recruited. Patients were clinically characterized by using validated questionnaires. Plasma neurosteroid levels were measured by liquid chromatography-tandem mass spectrometry. Results: We found disease-specific changes in neurosteroid levels in our study groups. For example, allopregnanolone levels were significantly increased in episodic migraine and chronic migraine patients than in control subjects, whereas they were reduced in patients affected by cluster headache. Dehydroepiandrosterone and dehydroepiandrosterone sulfate levels were reduced in patients affected by chronic migraine, but did not change in patients affected by cluster headache. Conclusion: We have shown for the first time that large and disease-specific changes in circulating neurosteroid levels are associated with chronic headache disorders, raising the interesting possibility that fluctuations of neurosteroids at their site of action might shape the natural course of migraine and cluster headache. Whether the observed changes in neurosteroids are genetically determined or rather result from exposure to environmental or intrinsic stressors is unknown. This might also be matter for further investigation because stress is a known triggering factor for headache attacks in both migraineurs and cluster headache patients

The effects of dietary counseling on children with food allergy: a prospective, multicenter intervention study.

Although dietary counseling is generally recommended in children with food allergy (FA), its effect on the nutritional status of these patients has not yet been evaluated. Our nonrandomized multicenter prospective intervention study was undertaken to investigate the effects of dietary counseling on children with FA. Anthropometric data, dietary intakes, and laboratory biomarkers of nutritional status were evaluated in children with FA (aged 6 to 36 months) before and after dietary counseling, by multidisciplinary teams composed of pediatricians, dietitians, and nurses. Ninety-one children with FA (49 boys and 42 girls; mean age 18.9 months, 95% CI 16.5 to 21.3) were evaluated; 66 children without FA (41 boys and 25 girls; mean age 20.3 months, 95% CI 17.7 to 22.8) served as controls providing baseline values only. At enrollment, energy and protein intakes were lower in children with FA (91 kcal/kg/day, interquartile range [IQR]=15.1, minimum=55.2, maximum=130.6; and 2.2 g/kg/day, IQR=0.5, minimum=1.5, maximum=2.7, respectively) than in children without FA (96 kcal/kg/day, IQR=6.1, minimum=83.6, maximum=118.0; and 4.6 g/kg/day, IQR=1.2, minimum=2.0, maximum=6.1, respectively; P<0.001). A weight to length ratio <2 standard deviations was more frequent in children with FA than in children without FA (21% vs 3%; P<0.001). At 6 months following dietary counseling, the total energy intake of children with FA was similar to the baseline values of control children. Dietary counseling also resulted in a significant improvement of their anthropometric and laboratory biomarkers of nutritional status. The results of our study support the crucial role of dietary counseling in the clinical management of children with FA