Effectiveness of fissure sealants on initial caries lesions (ICDAS 1-3) of permanent molars: A 4-year follow-up.

AIM: The aim of the present prospective study was to evaluate the retention and effectiveness of two types of sealants (clear vs. opaque) on early pit and fissure occlusal non-cavitated ICDAS II #1-3, caries lesions of permanent posterior teeth of children. MATERIALS AND METHODS: Study Design: 6986 pit and fissure occlusal surfaces were randomly sealed with clear or opaque sealants out of which, 5828 sealants were placed on sound and 1158 on questionable surfaces, while 3508 were clear and 3478 opaque sealants. The mean age of the sample at initial sealant placement was 9.5 (±2.9) years and the follow-up time was 12-48 months. The median (IQR, range) follow-up time was 17.9 (8.7-28.6) months. Study inclusion and exclusion criteria applied to the combined database in order to select the study sample. Teethmate™ F-1 natural and opaque sealants (Kuraray, Hattersheim am Main, Germany) were applied following the standard procedure of preparation with moisture control kept by cotton rolls handled Dri-Angles" and a 30 seconds acid-etch with 37% ortho-phosphoric acid gel was used followed by 10 sec air-water spraying washing and polymerization for 20x2 sec. Sealants were applied on sound tooth surfaces (ICDAS #0) with no visible defects or on surfaces with early caries lesions (ICDAS #1-3), randomly and interchangeably on the upper or lower Jaw. Total retention was considered when all pits and fissures were completely sealed, while partial or complete loss was scored as one code, although was registered separately. STATISTICS: Separate analyses were performed for each type of failure (loss of sealant or restoration). Cumulative probabilities of failure over time after sealant placement, overall or by specific characteristics, were calculated using the Kaplan-Meier method. Association between these characteristics and the hazard of failure were investigated using appropriate Cox proportional hazard models. RESULTS: Sealed surfaces with ICDAS II # 1-3, showed 100% higher probability of having a restoration and 60% higher probability of sealant loss, with both differences being statistically significant (aHR=2.03, p=0.046), adjusted for age, sex, type of sealant and location of surface. Opaque sealants presented statistically significant (p 0.009) higher re-application rate, while fissures had 70% statistically significant (p<0.001) higher probability for resealing with time compared to pits, with gender not affecting sealant retention while the earlier a sealant was placed on children's teeth, the more probable it was to need resealing or restoration (p <0.012). CONCLUSIONS: The therapeutic use of sealants on occlusal surfaces of posterior permanent molars with early carious lesions (ICDAS II 1-3) is inferior compared to sound surfaces, showing higher sealant failures and restorations.

Simulation-based teaching versus point-of-care teaching for identification of basic transoesophageal echocardiography views: a prospective randomised study.

In recent years, the use of transoesophageal echocardiography has increased in anaesthesia and intensive care. We explored the impact of two different teaching methods on the ability of echocardiography-naïve subjects to identify cardiac anatomy associated with the 20 standard transoesophageal echocardiography imaging planes, and assessed trainees' satisfaction with these methods of training. Fifty-two subjects were randomly assigned to one of two groups: a simulation-based and a theatre-based teaching group. Subjects undertook video-based tests comprised of 20 multiple choice questions on echocardiography views before and after receiving echocardiography teaching. Subjects in simulation- and theatre-based teaching groups scored 40% (30-40 [20-50])% and 35% (30-40 [15-55])% in the pre-test, respectively (p = 0.52). Following echocardiography teaching, subjects within both groups improved upon their pre-test knowledge (p < 0.001). Subjects in the simulation-based teaching group significantly outperformed their theatre-based group counterparts in the post-intervention test (p = 0.0002).

Phosphorylation-dependent binding of hepatitis B virus core particles to the nuclear pore complex.

Although many viruses replicate in the nucleus, little is known about the processes involved in the nuclear import of viral genomes. We show here that in vitro generated core particles of human hepatitis B virus bind to nuclear pore complexes (NPCs) in digitonin-permeabilized mammalian cells. This only occurred if the cores contained phosphorylated core proteins. Binding was inhibited by wheat germ agglutinin, by antinuclear pore complex antibodies, and by peptides corresponding either to classical nuclear localization signals (NLS) or to COOH-terminal sequences of the core protein. Binding was dependent on the nuclear transport factors importins (karyopherins) alpha and beta. The results suggested that phosphorylation induces exposure of NLS in the COOH-terminal portion of the core protein that allows core binding to the NPCs by the importin- (karyopherin-) mediated pathway. Thus, phosphorylation of the core protein emerged as an important step in the viral replication cycle necessary for transport of the viral genome to the nucleus.

Fluoride concentrations of infant foods and drinks in the United Kingdom.

Fluoride analyses of baby foods were carried out using a microdiffusion technique, which was found to be reproducible and accurate with less than 8% error. Analysis of 113 baby foods and drinks showed a wide range of fluoride concentrations: 0.01-0.31 mg F/kg for baby milk products; 0.04-0.72 mg F/kg for meat products; 0.04-0.70 mg F/kg for cereals; 0.03-0.48 mg F/kg for vegetable products; 0.03-0.07 mg F/kg for fruits; 0.02-0.28 mg F/kg for desserts, and 0.01-0.51 mg F/l for baby drinks. None of the baby foods and drinks contained fluoride of a sufficiently high concentration to be of concern or likely to contribute to enamel mottling, when used in the normal way.