Adenosine kinase (ADK) inhibition with ABT-702 induces ADK protein degradation and a distinct form of sustained cardioprotection.

Pharmacological inhibition of adenosine kinase (ADK), the major route of myocardial adenosine metabolism, can elicit acute cardioprotection against ischemia-reperfusion (IR) by increasing adenosine signaling. Here, we identified a novel, extended effect of the ADK inhibitor, ABT-702, on cardiac ADK protein longevity and investigated its impact on sustained adenosinergic cardioprotection. We found that ABT-702 treatment significantly reduced cardiac ADK protein content in mice 24-72 h after administration (IP or oral). ABT-702 did not alter ADK mRNA levels, but strongly diminished (ADK-L) isoform protein content through a proteasome-dependent mechanism. Langendorff perfusion experiments revealed that hearts from ABT-702-treated mice maintain higher adenosine release long after ABT-702 tissue elimination, accompanied by increased basal coronary flow (CF) and robust tolerance to IR. Sustained cardioprotection by ABT-702 did not involve increased nitric oxide synthase expression, but was completely dependent upon increased adenosine release in the delayed phase (24 h), as indicated by the loss of cardioprotection and CF increase upon perfusion of adenosine deaminase or adenosine receptor antagonist, 8-phenyltheophylline. Importantly, blocking adenosine receptor activity with theophylline during ABT-702 administration prevented ADK degradation, preserved late cardiac ADK activity, diminished CF increase and abolished delayed cardioprotection, indicating that early adenosine receptor signaling induces late ADK degradation to elicit sustained adenosine release. Together, these results indicate that ABT-702 induces a distinct form of delayed cardioprotection mediated by adenosine receptor-dependent, proteasomal degradation of cardiac ADK and enhanced adenosine signaling in the late phase. These findings suggest ADK protein stability may be pharmacologically targeted to achieve sustained adenosinergic cardioprotection.

Influence of autoclave sterilization on bond strength between zirconia frameworks and Ti-base abutments using different resin cements.

STATEMENT OF PROBLEM: Zirconia frameworks luted on titanium bases have been increasingly used for implant-supported prostheses. A reliable bond strength between the framework and the base is a key factor for clinical success. Autoclaving of the abutments before clinical use has been strongly suggested since abutments have been classified as class II medical devices. However, comprehensive knowledge on the susceptibility of the composite resin luting agents' adhesion to autoclave sterilization is lacking. PURPOSE: The purpose of this in vitro study was to assess the bond strength between zirconia frameworks and titanium bases using different composite resin luting agents with and without thermocycling and autoclaving. MATERIAL AND METHODS: A total of 200 titanium implants were copy milled and 200 zirconia frameworks (Cercon) were generated by computer-aided design and computer-aided manufacturing (CAD-CAM). They were adhesively luted using Multilink Hybrid Abutment (MHA), Panavia F2.0 (PF2), Panavia V5 (PV5), RelyX Ultimate (RXU), or Panavia SA Cement Plus (PSA). Autoclaving (134 °C, 0.21 MPa, 5.5 minutes) and thermocycling (3000 cycles, 5 °C and 55 °C) were performed. The push out bond strength was tested at a crosshead speed of 1 mm/min. Statistical analysis was performed by using the Mann-Whitney U test (α=.05) and the family-wise error rate method. RESULTS: Median bond strength values (interquartile range) after autoclaving and thermocycling ranged between 33.7 (26.7-41.8) MPa for MHA and 7.6 (7.3-8.5) MPa for PF2. MHA showed significantly higher values than all other composite resin luting agents regardless of thermocycling or autoclaving. PV5 showed equal or higher bond strength values than PSA, RXU, and PF2. Autoclaving had no significant influence on MHA or PV5, but had a negative effect on PSA and RXU. The family-wise error rate method showed that both the composite resin luting agent and autoclave sterilization had an overall influence on bond strength. CONCLUSIONS: MHA and PV5 were not significantly influenced by autoclaving and showed acceptable bond strength values. Because MHA showed significantly higher bond strength than all other materials and is released for autoclaving by the manufacturer, it is the first choice for extraoral bonding of zirconia frameworks to titanium bases. Manufacturers who state the indication of extraoral cementation of frameworks on titanium bases should also indicate whether their composite luting material is affected by autoclaving.

Oral Health Behaviour and Oral Hygiene of Dental Professionals and Laypersons - A Survey Performed in Lower Saxony, Germany.

PURPOSE: The aim of this survey-based cross-sectional study was to analyse the oral health behaviour of dental professionals and persons without professional dental knowledge (layperson group) regarding the use and selection of tools for their personal dental hygiene. MATERIALS AND METHODS: A total of 356 persons participated in the survey (dental professional group: 160; layperson group: 196). Information regarding dental hygiene habits, such as toothbrush use, toothbrushing habits, and the use of additional dental hygiene tools was determined using a standardised questionnaire. Data were analysed using the chi-squared and Wilcoxon tests, with significance set at p < 0.05. RESULTS: 93% of the dental professional group and 89% of layperson group used manual toothbrushes (p = 0.03). Power toothbrushes were used by 57% of those surveyed in the dental professional group and 37% of those in the layperson group (p < 0.01). In the dental professional group, the duration of toothbrushing was significantly longer and it was performed more often compared to layperson group (p < 0.001). The use of dental floss and interdental brushes in the layperson group (dental floss 38%, interdental brush 5%) was considerably lower than in the dental professional group (dental floss 84%, interdental brush 11%; p < 0.001). CONCLUSION: The results of the survey on oral health behaviour revealed significant differences between the groups. The acceptance of additional tools for personal dental hygiene was low, such as dental floss and interdental brushes. Given the great importance of these tools for biofilm control, they should be emphasised in motivational measures and instructions regarding oral care performed at home.

Influence of proximal box elevation technique on marginal integrity of adhesively luted Cerec inlays.

OBJECTIVES: This in vitro study evaluated the marginal quality of Lava Ultimate inlays in deep proximal cavities with and without proximal box elevation (PBE) before and after thermomechanical loading (TML). MATERIALS AND METHODS: Mesio-occluso-distal cavities with proximal boxes beneath the cementoenamel junction (CEJ) were prepared in 24 human molars. Then, one of the proximal boxes was elevated with Filtek Supreme above the CEJ. The specimens were divided into three groups (n = 8). The inlays of group A were adhesively luted to the cavities with Scotchbond Universal and Rely X Ultimate, the inlays of group B with Monobond Plus, Syntac, and Variolink II, and the inlays of group C with Clearfil Ceramic Primer and Panavia SA Cement. Epoxy resin replicas were taken before and after thermomechanical loading (1,200,000 cycles, 55 °C/5 °C, max. load 50 N). Marginal integrity at the different interfaces tooth/PBE, tooth/dentine, inlay/PBE, inlay/dentine was evaluated with scanning electron microscopy (×200). The percentage of continuous margin (% of total proximal margin length) was compared between the groups before and after TML. STATISTICS: Mann-Whitney U test (p = 0.05). RESULTS: No significant differences (p > 0.05) before and after TML were found between the three groups for bonding the inlay to dentine or to PBE composite. CONCLUSIONS: The marginal integrities of bonding inlays directly to dentine are not different from bonding inlays to a proximal box, which has been elevated by a composite filling material. For deep proximal cavities, the PBE technique could be an alternative technique to conventional methods. Clinical research is needed to confirm.

Clinical performance of a new glass ionomer based restoration system: a retrospective cohort study.

OBJECTIVES: This retrospective clinical study evaluated the suitability of a glass ionomer system as a permanent restoration material in posterior cavities. METHODS: 26 Class I (1-surface (S1)) and 125 Class II (84 2-surface (S2), 41 3- and 4-surface (S3+)) restorations were placed in permanent molars (n=94) and premolars (n=57) in 43 patients in 6 dental practices. Restorations were evaluated at 4.5× magnification using modified USPHS criteria. Statistical analysis was performed using the Pearson's Chi-square-test (p ≤ 0.05). RESULTS: The median age of the restorations was 24 months. No failures were observed. The original volume of the restoration was retained in 88.5% of the S1, in 64.2% of the S2 and in 53.7% of the S3+ restorations. A distinct volume loss in S1 restorations was evident in 3.8%. A visible and perceptible roughness was shown in 11.5% of the S1, in 14.3% of the S2 and in 24.4% of the S3+ restorations. Marginal disintegrities occurred in none of the S1, in 1.2% of the S2 and in 7.3% of the S3+ restorations. A distinct marginal discoloration was found less than 1%. CONCLUSIONS: Within the limitations of this study it can be concluded that EQUIA can be used as a permanent restoration material for any sized Class I and in smaller Class II cavities. However, results of ongoing prospective studies shall provide a more exact indication definition in Class II situations. SIGNIFICANCE: Modern glass ionomer systems may not only serve as long-term temporaries, but also as permanent restorations in posterior teeth.

Bee-venom allergy in children: long-term predictive value of standardized challenge tests.

Venom immunotherapy (VIT) is able to protect insect venom-allergic patients against life-threatening sting reactions. Standardized sting challenges can be used as a diagnostic tool to check whether VIT is required. No data are available on the long-term predictive value of sting challenge tests. The purpose of this study was to investigate the long-term predictive value of sequential bee-sting challenges with respect to the ability to predict future sting reactions in bee-venom (BV) allergic children. Between 1988 and 1992, 92 BV-allergic children had been challenged with sequential bee stings at intervals of 2-6 weeks to determine the necessity of VIT. In 1996, all 92 families were followed-up using standardized telephone interviews. Until the follow-up, 61 children (66.3%) had experienced at least one natural bee sting. Based on the results of the initial challenge tests, 13 of the 61 patients had been started on VIT. Two of these 13 (15.4%) developed systemic reactions 1 year after VIT of 5 years, of which one was mild and one was severe. Among the 48 re-stung patients who were not treated with VIT, three children (6.3%) experienced mild systemic reactions, whereas 45 children reported no more than a local reaction. The long-term predictive value of sequential bee-sting challenge tests for systemic reactions in children not treated with VIT remained at a level of 93.8% (95% confidence interval: 82.8-98.7%) even over a period of more than 6 years. Based on this data, we conclude that sequential bee-sting challenges are a powerful tool to determine the necessity for VIT in BV-allergic children.