Oral health and dental care of older persons-A systematic map of systematic reviews.

OBJECTIVES: To examine the current knowledge on oral health status and dental care of older persons through a systematic mapping of systematic reviews of low or moderate risk of bias. BACKGROUND: Geriatric dentistry covers all aspects of oral health and oral care of older persons. Oral health is part of general health and contributes to a person's physical, psychological and social wellbeing. METHODS: A literature search was performed in three different databases (PubMed, The Cochrane Library and Cinahl) within 12 domains: Dental caries, periodontitis, Orofacial pain and temporomandibular joint (TMJ) pain, mucosal lesions, oral motor function, dry mouth, halitosis, interaction between oral status and other medical conditions, ability to interrelate and communicate, quality of life, ethics and organisation of dental care for older persons. Systematic reviews were identified and scrutinised, highlighting scientific knowledge and knowledge gaps. RESULTS: We included 32 systematic reviews of which 14 were judged to be of low/moderate risk of bias. Most of the domains lack systematic reviews with low or moderate risk of bias. In two of the domains evidence was identified; in institutionalised people aged 65 or older, effective oral hygiene can prevent pneumonia. Furthermore, there is an evidence of a relationship between malnutrition (protein energy-related malnutrition, PEM) and poor appetite and edentulousness. CONCLUSIONS: There is an urgent need for further research and evidence-based knowledge within most domains in geriatric dentistry and in other fields related to oral health and dental care for older persons striving for multi-disciplinary research programmes.

Enzyme kinetics by GH7 cellobiohydrolases on chromogenic substrates is dictated by non-productive binding: insights from crystal structures and MD simulation.

Cellobiohydrolases (CBHs) in the glycoside hydrolase family 7 (GH7) (EC3.2.1.176) are the major cellulose degrading enzymes both in industrial settings and in the context of carbon cycling in nature. Small carbohydrate conjugates such as p-nitrophenyl-ß-d-cellobioside (pNPC), p-nitrophenyl-ß-d-lactoside (pNPL) and methylumbelliferyl-ß-d-cellobioside have commonly been used in colorimetric and fluorometric assays for analysing activity of these enzymes. Despite the similar nature of these compounds the kinetics of their enzymatic hydrolysis vary greatly between the different compounds as well as among different enzymes within the GH7 family. Through enzyme kinetics, crystallographic structure determination, molecular dynamics simulations, and fluorometric binding studies using the closely related compound o-nitrophenyl-ß-d-cellobioside (oNPC), in this work we examine the different hydrolysis characteristics of these compounds on two model enzymes of this class, TrCel7A from Trichoderma reesei and PcCel7D from Phanerochaete chrysosporium. Protein crystal structures of the E212Q mutant of TrCel7A with pNPC and pNPL, and the wildtype TrCel7A with oNPC, reveal that non-productive binding at the product site is the dominating binding mode for these compounds. Enzyme kinetics results suggest the strength of non-productive binding is a key determinant for the activity characteristics on these substrates, with PcCel7D consistently showing higher turnover rates (kcat ) than TrCel7A, but higher Michaelis-Menten (KM ) constants as well. Furthermore, oNPC turned out to be useful as an active-site probe for fluorometric determination of the dissociation constant for cellobiose on TrCel7A but could not be utilized for the same purpose on PcCel7D, likely due to strong binding to an unknown site outside the active site.

Gingivitis and periodontitis are related to repeated high levels of circulating tumor necrosis factor-alpha in patients with rheumatoid arthritis.

BACKGROUND: Several studies have indicated a relationship between rheumatoid arthritis and periodontal disease. The aim of this study was to investigate the association between the circulating proinflammatory mediators tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta, prostaglandin E(2), serotonin, rheumatoid factor, and periodontitis in patients with rheumatoid arthritis. METHODS: Nineteen patients, 17 women and two men, with rheumatoid arthritis were included. These patients had been examined repeatedly (average of three times) with regard to inflammatory markers and mediators from blood samples. Their teeth, excluding third molars, were examined with regard to number, clinical attachment level (CAL), probing depth (PD), and gingival bleeding on probing (BOP). Assessment of furcation involvement and increased tooth mobility was also made. All patients were non-smokers. Thirty healthy individuals, 20 women and 10 men, were included as a reference regarding TNF-alpha. RESULTS: Patients with high levels of time-averaged TNF-alpha from repeated plasma samples had a higher frequency of BOP as well as increased CAL and PD compared to those with low levels. CONCLUSION: Gingivitis and periodontitis are related to high levels of circulating TNF-alpha in patients with rheumatoid arthritis.

Characterization of micromachined ultrasonic transducers using light diffraction tomography.

This paper demonstrates that light diffraction tomography can be used to measure the acoustic field of micromachined ultrasonic transducers (MUT) in cases in which standard methods like hydrophone and microphone measurements fail. Two types of MUTs have been characterized with the method, one air-coupled capacitive MUT (cMUT) and one waterloaded continuous wave (CW) miniature multilayer lead zirconate titanate (PZT) transducer. Light diffraction tomography is an ultrasound measurement method with some special characteristics. Based on the interaction of light and ultrasound, it combines light intensity measurements with tomography algorithms to produce a measurement system. The method offers nonperturbing pressure measurements with high spatial resolution. It has been shown that, under certain circumstances, light diffraction tomography can be used as an absolute pressure measurement method with accuracy in the order of 10% in water and 13% in air. The results show that air-coupled cMUTs in the frequency range of about 1 MHz as well as the extreme near field of a miniaturized CW 10 MHz water-loaded transducer were successfully characterized with light diffraction tomography.

Longevity of posterior resin composite restorations in adults ­ A systematic review.

OBJECTIVE: To conduct a systematic review of the literature on the longevity of posterior resin composite restorations in adults. MATERIAL AND METHODS: A systematic literature search was conducted according to pre-determined criteria for inclusion and exclusion. The studies selected were prospective clinical trials with a minimum follow-up time of 4 years, 40 restorations per experimental group and an annual attrition rate of less than 5%. Initially, abstracts and full-text articles were assessed independently and the assessment was subsequently agreed on by five reviewers. The methodological quality of the studies was assessed according to the Swedish Council on Health Technology Assessment (SBU) standard checklist for determining the extent to which studies meet basic quality criteria. RESULTS: In all, the literature search identified 4275 abstracts and 93 articles were read in full-text. There were eighteen studies which met the criteria for inclusion, eight of which were included in the analysis. There were 80 failures of restorations with a total follow-up time at risk for failure of 62,030 months. The overall incidence rate for all causes of failure was 1.55 lost restorations per 100 restoration years. The most common biological reason for failure (a total of 31 restorations) was secondary caries, with or without fracture of the restoration. The quality of the evidence was low. CONCLUSIONS: In an efficacy setting, the overall survival proportion of posterior resin composite restorations is high. The major reasons for failure are secondary caries and restoration fracture which supports the importance of adequate follow-up time. CLINICAL SIGNIFICANCE: The overall survival proportion of posterior composite restorations was high, but the results cannot be extrapolated to an effectiveness setting. The importance of adequate follow-up time is supported by the finding that secondary caries often occurred after 3 years or later.