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Removable prosthodontics are often associated with mechanical troubles in daily use, such as fracture or deformation. These troubles render prostheses unusable and reduce wearers' QOL. Various reinforcements are used to prevent such problems, but consensus on reinforcement has not been reached. This review aimed to summarise the effects of reinforcement and to propose favourable reinforcement based on material, design and position in the prostheses. Initially, 139 articles were selected by electronic and manual searches. After exclusion of 99 articles based on the exclusion criteria, 40 articles were finally included in the review. Electronic searches were performed for articles published from 2005 to 2015 in PubMed, EMBASE, MEDLINE and Cochrane Library, and manual searches were performed in 10 journals relevant to the topic of removable prosthodontics. For in vitro studies, certain dental alloys and fibres were mainly used. Their forms were different, including complicated forms in dental alloys and various forms in fibres. The materials were examined for mechanical properties like fracture strength, flexural strength and elastic modulus and compared with one another or without reinforcement. There were a few clinical studies and one longitudinal study. Cast metal reinforcement seemed to be most favourable in terms of fracture toughness and stiffness. The most favourable forms differed depending on the prostheses, but placement around thin and deformable areas was effective. However, randomised or longitudinal clinical reports and comparative clinical studies on the use of reinforcement were still lacking and such studies are necessary in the future. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine a longitudinal clinical performance of magnetic attachments used for natural overdenture abutments. The study included 131 patients who had used removable prostheses (complete overdentures 31%, partial dentures 69%) more than 5 years (40-90 years old) with 211 magnetic attachments on natural abutments (Magfit 400 or 600; Aichi Steel co., Aichi, Japan) treated in 15 clinics using a standardized protocol. Analyses were performed on the degree of patient satisfaction regarding retention, complications of magnets (corrosion, detachment from denture base), abutments (pain during mastication, periodontal pocket formation, inflammation, mobility), and dentures (fracture etc.). Ninety-seven percent of patients were satisfied with the retention and stability of their dentures. No corrosion of magnet was observed, and 19 magnets were detached. Most frequent complication of abutments was periodontal pocket formation (52%), followed by the inflammation (29%), increase in mobility (27%) and pain (4%). Magnetic attachment on natural tooth abutments provided a viable and long-term treatment option. [ABSTRACT FROM AUTHOR]

The structural design of removable partial dentures (RPDs) is critical for preventing distortion of the prosthesis, protecting abutment teeth and residual ridges as well as for high masticatory performance. The aim of this study was to clarify the feasibility and utility of a computer-aided designing (CAD) system with finite element analysis (FEA) for molar teeth arrangement in unilateral distal extension base RPDs. The shapes of artificial teeth and residual ridge were measured and converted into point group data. Solid models were created from surface-modelled point group data in a 3D surface CAD format. An occlusal rim was created on the residual ridge mucosa and the occlusal rim - residual ridge mucosa model with FEA function was created. Stress distribution on the residual ridge mucosa was compared by changing the loading point. The artificial teeth were then arranged in locations with the lowest amount of stress. After building an artificial teeth – saddle – residual ridge mucosa model, stress distribution in the residual ridge mucosa was re-evaluated by simulating occlusal force. On the occlusal rim - residual ridge mucosa model, stress was reduced when the loading point was located around the buccal shelf where functional cusps of artificial teeth were charted. It was confirmed that stress distribution in the residual ridge mucosa was equalized on the artificial teeth – saddle – residual ridge mucosa model. This system might be clinically useful tool for designing RPDs if FEA-guided designing of retainers and connectors can be added. [ABSTRACT FROM AUTHOR]

This study investigated associations between temporomandibular joint (TMJ) sounds and occlusal force or masticatory performance stratified by posterior occlusal supports in older Japanese adults. The subjects consisted of 1646 independently living people over 60 years. Masticatory performance, occlusal force, TMJ sounds and maximal mouth opening were examined. Posterior occlusal supports were classified by the Eichner Index. The prevalence of TMJ sounds was 27·7%, limitation of mouth opening (<40 mm) was 7·9% and TMJ pain was only 1·5%. In the Eichner C group, TMJ sounds were significantly associated with lower occlusal force (OR = 3·20, P = 0·046) and lower masticatory performance (OR = 3·18, P = 0·041) after controlling for gender and age. These associations were not found in the Eichner A and B groups. Within the limitations of this study, the presence of TMJ sounds, even if they were symptomless, was associated with impairment of masticatory function in older adults with reduced occlusal support. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the influence of coping heights on the strain around the abutment teeth and at the middle part of mandibular overdentures, using strain gauges. A mandibular edentulous model with a silicone artificial mucosa of thickness 2 mm was made. Two artificial roots were embedded on both sides in the canine position. The coping had a dome-shaped upper surface at a height of 0, 2, 4 and 6 mm. On the lingual polished surface of the overdenture, three strain gauges were attached in the left canine position at the vertical level corresponding to the top of the 6, 4 and 2 mm copings and two strain gauges were attached in the middle section (upper and lower). A vertical loading of 49 N was applied on the occlusal surface of first premolar, first molar and second molar. When loading on the first premolar adjacent to an abutment, the largest tensile strain was observed on the overdenture surface close to the top of each coping, independent of coping heights. When loading on the first premolar on the opposite side, the tensile strains around the coping were remarkably smaller. In the middle part of the overdenture, the compressive strains became larger by reducing the coping height or loading on distal point. The largest tensile strain was observed on the overdenture surface close to the top of copings, independent of coping heights. [ABSTRACT FROM AUTHOR]

Recently, a newly developed magnetic attachment with stress breaker was used in retentive components in overdentures. Excessive lateral stress has a more harmful effect on natural teeth than axial stress, and the magnetic attachment with stress breaker is expected to reduce lateral forces on abutment teeth and protect it teeth from excessive stress. However, the properties of this retainer have not yet been determined experimentally. This study compares the lateral forces on abutment teeth for three retainers under loading on the denture base in a model study. A mandibular simulation model is constructed to measure lateral stress. Three types of retentive devices are attached to the canine root. These devices include the conventional root coping, the conventional magnetic attachment and the new magnetic attachment with stress breaker. For each retentive device, load is generated on the occlusal table of the model overdenture, and the lateral stress on the canine root and the displacement of the overdenture measured. The magnetic attachment with stress breaker does not displace the denture and exhibits lower lateral stress in the canine root than conventional root coping and magnetic attachments. [ABSTRACT FROM AUTHOR]

The Wilms’ tumour suppressor gene (WT1) encodes a zinc finger-containing nuclear protein essential for kidney and urogenital development. Initially considered a transcription factor, there is mounting evidence that WT1 has a role in post-transcriptional processing. Using the interspecies heterokaryon assay, we have demonstrated that WT1 can undergo nucleocytoplasmic shuttling. We have also mapped the region responsible for nuclear export to residues 182–324. Our data add further complexity to the role of WT1 in trancriptional and post-transcriptional regulation. [Copyright &y& Elsevier]

1. Phytoncides are volatile substances released mainly from trees. We studied whether phytoncides can reduce stress responses in stroke-prone spontaneously hypertensive rats (SHRSP). 2. Under the restraint stress, SHRSP exposed to phytoncides showed lower blood pressure than those without the exposure (186.8 +/- 3.9 vs 207.7 +/- 3.4 mmHg, respectively, P < 0.01 by Student's t-test). 3. Consistent with the observation above, the plasma concentration of catecholamines under the restraint stress was lower in the phytoncides group than in the control group. 4. Based on these results, we concluded that phytoncides reduced the cardiovascular response to restraint stress in SHRSP.

1. Adrenomedullin-2 (AM2) is a novel peptide originally found in a fish and it is structurally related to mammalian AM or fish AM1. Cloning of AM2 cDNA in the mouse, rat and human has been successful. In the present study, the vasodilatory effect of synthetic human AM2 was analysed in isolated artery ring preparations of porcine. 2. Vasodilatory effect of AM2 was the most potent in the coronary artery, followed by the carotid and supramesenteric arteries, but absent in the femoral, pulmonary and renal arteries. 3. The effect of AM2 was equipotent with that of human AM/AM1 in these arteries. 4. AM2-induced relaxation was inhibited by human CGRP (8-37), but not by human AM/AM1 (22-52), suggesting that the vasodilatory response to AM2 is mediated through the CGRP1 receptor. 5. AM2 may share the same receptor (complex) with AM/AM1 for the vasorelaxation. This is the first report of the vasodilatory responses to AM2 in isolated vasculature.

1. To understand the roles of a putative hypertension gene in the chromosome 1 quantitative trait locus (QTL) region, the response to restraint stress was studied in strains congenic for this QTL. 2. To establish congenic strains, the QTL region was introgressed from stroke-prone spontaneously hypertensive rats (SHRSP)/Izm to Wistar-Kyoto/Izm (WKY/Izm) rats by repeated backcrossing. Two congenic strains (WKYpch1.0 and WKYpch1.1) were established to cover the whole QTL region between D1Wox29 and D1Arb21 (approximately 40 cM) and a smaller region between D1Smu11 and D1Arb21 (approximately 10 cM), respectively. After telemetry probes were implanted, rats were exposed to restraint stress to investigate the blood pressure response. 3. Basal blood pressure measured by radiotelemetry differed significantly between WKY rats and WKYpch1.0 (103 +/- 10 and 116 +/- 4 mmHg, respectively; P = 0.002 by anova). When exposed to restraint stress, WKYpch1.0 showed a greater increase in blood pressre than did WKY rats. The exaggerated response in the WKYpch1.0 strain was abolished by chemical sympathectomy using guanethidine. The WKYpch1.1 rats did not differ significantly from WKY rats either in basal blood pressure or in the response to restraint stress. 4. In conclusion, a QTL for high blood pressure was successfully introgressed in the established congenic strain, WKYpch1.0. A gene (or genes) in the chromosome 1 QTL region modulates the cardiovascular responses to restraint stress in these congenic rats, probably through the sympathetic nervous system.

Over-expression of the c-myb gene and expression of activated forms of myb are known to transform haemopoietic cells, particularly cells of the myeloid lineage. Truncations or mutations that disrupt the negative regulatory domain (NRD) of the Myb protein confer an increased ability to transform cells. Although it has proved difficult to link mutations in c-MYB to human leukaemia, no studies investigating the presence of mutations within the c-MYB NRD have been reported. Therefore, we have performed mutational analysis of this region, using polymerase chain reaction-single-stranded conformation polymorphism and sequence analysis, in 26 patients with acute or chronic myeloid leukaemia. No mutations were detected, indicating that mutation of this region of the Myb protein is not common in the pathogenesis or progression of these diseases.

1. The effects of a formula of traditional Chinese medicine, TBL-1, on collagen-induced arthritis (CIA) were investigated in DBA/1J mice. 2. From 4 weeks after the first immunization with bovine type II collagen (CII), TBL-1 or indomethacin was administered orally for 13 weeks. 3. Clinical scores of CIA were decreased by both TBL-1 and indomethacin intervention compared with the control CII-immunized group. 4. Radiographic scores of phalangeal destruction were markedly improved by TBL-1 intervention (P < 0.001), but indomethacin failed. 5. The suppressive effects of TBL-1, but not indomethacin, were manifested in reduced serum anti-CII antibody titres (P < 0.001). 6. These findings suggest that TBL-1 may play a role in regulating some immune responses in the present arthritis model.