[Is self-confidence a factor for successful breastfeeding?]. / Les mères confiantes en elles allaitent-elles plus longtemps leur nouveau-né ?

CONTEXT: Maternal self-confidence and self-efficacy in breastfeeding are recognized as factors positively associated with the initiation and duration of breastfeeding. OBJECTIVE: To evaluate the importance of this association using the Breast Feeding Self-Efficacy Scale (BSES). METHOD: This prospective study was conducted in 2012 in the Jeanne-de-Flandre maternity department in the Lille University Hospital (France). During their time in the maternity department, breastfeeding mothers who participated in the study completed the BSES, a brief self-assessment of their feelings of self-efficacy relating to breastfeeding. They then received follow-up telephone interviews at 1 and 3 months postpartum. RESULTS: One hundred and forty-nine mothers were included in the study. Breastfeeding rates were 86.5% at 1 month and 60% at 3 months. The BSES score of mothers who continued to breastfeed at 1 and 3 months was significantly higher than the score of mothers who had already weaned their children, with an AUROC of 0.72 at 3 months. This confirmed the reliability of the BSES for predicting adherence to breastfeeding. The BSES score of mothers who had previously breastfed was significantly higher than for those breastfeeding for the first time. The threshold score for the BSES was determined as 116/165. CONCLUSION: It is important that mothers who lack confidence in their ability to breastfeed be identified early, whether on the maternity ward or even before this point. The value of BSES-based breastfeeding support intervention needs to be evaluated through randomized trials.

Three-dimensional pore-scale modelling of dentinal infiltration.

Dentine is the fundamental substrate of restorative dentistry, and its properties and characteristics are the key determinants of restorative processes. In contemporary restorative techniques, bonding to Dentine is created by the impregnation of the demineralised dentine by blends of resin monomers. In this paper, a numerical model of dentinal infiltration is proposed. The aim is to follow the resin front and to point out the optimal parameter set. The main tool is a level set technique to follow the evolving interface. It is coupled with the Navier-Stokes equation where capillary effect gives rise to the appearance of a new term in the variational approach than discretised by finite elements. Using an appropriate geometry representing demineralised dentine, the moving front is observed. First, a simulation of porosimetry test is achieved in order to validate the model. The two expected pore sizes are detected and the simulation also points out limitations of mercury intrusion porosimetry test in an educational way. Then a wetting fluid (representing the dental resin) is numerically infiltrated. In the dentinal porous network, capillarity is taken into account in our model by including a capillary term. A crucial conclusion is drawn from this study: resin application time by practitioners is sufficient if, in the infiltration process, the wetting phase is the resin.

Self-etching increases matrix metalloproteinase expression in the dentin-pulp complex.

In adhesive restorations, one major problem is hybrid layer degradation. At present, this deterioration is explained by the activation of the endogenous matrix metalloproteinases (MMPs) present in dentin due to the acidic property of adhesive systems. We hypothesized that self-etching adhesive should also stimulate the expression of MMPs in odontoblasts. In cultured tooth slices, we evaluated the changes in MMP-2 and proMMP-9 expression in the dentin-pulp complex after self-etching adhesive treatment on dentin cavities in immunochemistry and by zymography. The treatment resulted in increased MMP-2 expression in odontoblasts, as shown by immunohistochemistry. Zymography showed increased proMMP-9 and MMP-2 in dentin under self-etching treatment when pulp was present. These results showed that self-etching adhesive stimulates the secretion of MMPs from the dentin-pulp complex and, more precisely, by odontoblasts, suggesting that odontoblasts participate in hybrid layer degradation.

Bond strengths of nine current dentine adhesive systems to primary and permanent teeth.

The aim of this study was to compare the shear bond strength (SBS) of nine dentine bonding systems (DBS) of different classes to human primary and permanent dentine. Flat dentine occlusal surfaces were produced on human molars (100 primary, 100 permanent) by wet grinding on a 800-grit SiC paper. Nine DBS were applied following the manufacturers' instructions: One total etch multi-step system: Scotchbond Multipurpose Plus (3M/ESPE); Four total etch one-bottle system: Prime &Bond 2.1 (Dentsply), One Step (Bisco), Scotchbond 1 (3M/ESPE), and OptibondSolo Plus (Kerr); Three two-step self-etching primer systems: Clearfil Liner Bond 2 (Kuraray), Clearfil SE Bond (Kuraray), and Prime &Bond NT with NRC (Dentsply); An 'all-in-one' self-etching system: Prompt L-Pop (3M/ESPE). Composite (Z100; 3M/ESPE) cylinders (2 mm diameter, 3 mm high) were polymerized on the treated dentine surfaces and the specimens were stored at 37 degrees C for 24 h prior to testing. Twenty experimental groups were produced and tested. Statistical analysis revealed both a substrate and a bonding system effect. Two adhesive systems (One Step, Prime &Bond NT) had significantly higher bond strengths on permanent than on primary dentine. There was an effect of dentine bonding system on the mode of fracture. Although eight of the 10 DBS tested exhibited higher median SBS values on permanent dentine than on primary dentine, the dependent pairwise comparison identified a significant difference only for two groups. The use of simplified bonding systems does not necessarily result in improved bond strength to primary or to permanent dentine.

Influence of drying and HEMA treatment on dentin wettability.

OBJECTIVES: The aim of this study was to evaluate the effect of drying time and primer pre-application (35% HEMA in water) on water spreading/infiltration on dentin. METHODS: Freshly extracted molars were embedded in resin and sectioned on their coronal side. Flat occlusal dentin surfaces were prepared using wet SiC paper from nos. 80-4000. A computerized contact angle device complementing a special software (Wingoutt) was used to measure the contact angle (theta) kinetics of a reference liquid (pure H(2)O) in the ten groups each of ten dentin surfaces during 120 s: Gp1: etched (37% phosphoric acid for 15 s) and blot-dried; Gp2: 3 s dried; Gp3: 5 s air-dried; Gp4: 10 s air-dried; Gp5: 20 s air-dried; Gp6: 30 s air-dried; Gp7: 1 min dried with hair dryer; Gp8: 5 s air-dried and HEMA treated; Gp9: 30 s air-dried followed by HEMA treatment; Gp10: HEMA treated prior to 30 s air-drying. three drops were applied on each sample. 40 contact angles were recorded for each drop with a frequency of one measure every 3 s. A one-way ANOVA test was used for data analysis. A PLSD test was conducted to identify statistical differences between pairs of groups at a reliability level of 95%. RESULTS: At each measurement time, air-drying, whatever its duration, significantly decreased the wetting ability of the pure water on the etched dentin in comparison with the blot-dried group. The contact angle increases with drying time. No significant differences in water contact angle were obtained between 3, 5 and 10 s in spite of a slight decrease in the spreading/infiltration ability of water the longer the drying time. HEMA increases the spreading/infiltration ability of water on 5 or 30 s air-dried etched dentin surfaces; 30 s air-drying did not alter the spreading/infiltration ability of the water on etched and HEMA treated dentin. SIGNIFICANCE: Dentin hydrophobicity increases depending on air-drying time. HEMA-based primer allows to prevent collagen collapse, which may be created by air-drying and partly rewet the collapsed collagen network.

Meta-analytical review of factors involved in dentin adherence.

Literature data on adherence tests of dentin-bonding systems (DBS) may differ widely, even for the same DBS. The problem of bond testing is that materials are seldom compared with a standard, and experimental conditions often vary. We sought to identify the parameters that influence this variability. Using inclusion and exclusion criteria, we conducted a meta-analytical review of 75 articles, published between 1992 and 1996 in SCI reviews, that give bond strength data for 15 dentin-bonding agents of the so-called third and fourth generations. Seventeen selected parameters were classified into four groups: Group A includes factors related to the dentin substrate (i.e., nature of teeth); group B, composite and bonding area (i.e., composite stiffness); group C, storage conditions of the bonded samples (i.e., thermocycling); and group D, test design (i.e., crosshead speed). For each report, the experimental features, the bond strength means and standard deviations, and the failure mode were extracted and tabulated. Statistical Analysis System software was used to perform Pearson correlation analysis and analysis of variance, with bond strength as the dependent variable and experimental conditions as the independent variables. The meta-analytical review highlighted the significant influence of various parameters in the different groups: origin of dentin, types of teeth, pulpal pressure, tooth storage temperature, maximum storage time of teeth, and dentin depth in group A; type and stiffness of composite and bonding area in group B; storage of bonded samples (medium, temperature, and time) in group C, and testing mode and crosshead speed in group D. A significant positive correlation was observed between the mean bond strength and the rate of cohesive failure. It can be concluded from this study that some of these parameters should be controlled by the use of a standardized protocol. Unfortunately, the substrate-related variables are more difficult to control, even though their influence is consistent.

Reliability of in vitro microleakage tests: a literature review.

PURPOSE: The literature contains conflicting data about in vitro microleakage evaluations and their usefulness and reliability. No standardization has yet been established. Here we consider features of published studies that might affect the results of the in vitro microleakage tests. MATERIALS AND METHODS: We reviewed 144 in vitro microleakage studies, published in 14 international reviews between 1992 and 1998, which comprised 917 sets or groups of experiments. The published studies were entered in a database and compared using selected literature criteria: sample, cavities, restoration procedures, thermocycling and mechanical cycling, evaluation method. RESULTS: The methods employed vary widely. The most frequent methodological choices (%) were (1) specimen storage after extraction: duration (unspecified, 59.2), medium (distilled or deionized water, 33.8), temperature (unspecified, 52.2), additives (none, 47.0); (2) aging method (79.1): duration before aging (< 24 h, 35.9); medium and temperature of storage before aging (distilled or deionized water, 26.8; 37 degrees C, 54.3); (3) medium of cycling (tap water, 50.5), number of cycles ([250-500], 34.6), number of baths (2, 84.0), bath temperature (5 degrees C to 55 degrees C, 60.6), immersion dwell time (30 s, 44.3); (4) tracer: type (basic fuchsin, 40.7), time of immersion (after thermocycling and/or mechanical cycles, 64.1), immersion duration (basic fuchsin: 24 h, 59.5); assessment of dye penetration of sections (91.7): direction (perpendicular, 88.5), number (1, 47.1). CONCLUSION: The great variability in the methods used in these 144 studies prevented meta-analysis and comparison of the results, thus reducing the value of these methods.

[Effect of water storage and intrapulpal pressure on microleakage of three restorative materials]. / Nedvesség, valamint a szimulált intrapulpalis nyomás hatása az esztétikus tömóanyagok széli záródására.

Three different restorative materials, Z100 composite, F2000 compomer and Vitremer glass ionomer cement are currently proposed for Class V restorations. The aim of this in vitro study was to evaluate the influence of water storage and the simulated intrapulpal pressure (sIP) on the quality of the margins of class V restorations located both in enamel and dentin. The water resorption of restorative materials containing hydrophilic groups (compomers and glass ionomer cements) can favourably modify the marginal sealing ability by hydroscopic expansion. The influence of the sIP was specific to the material. While F2000 compomer and Vitremer glass ionomer cement were un-influenced by sIP, with Z100 composite a significant difference could be observed. It was concluded that F2000 compomer and Vitremer glass ionomer cement showed significantly less microleakage, which means a better marginal sealing ability than Z100 composite.

Influence of surface treatment on adherence energy of alloys used in bonded prosthetics.

Usually, shear or tensile tests are used to assess bond strengths between resin and metal. In this study, a cleavage test, the Double Cantilever Beam test, was performed to measure the adherence energy in air and in water between a 4-META resin, and five alloys (palladium, palladium-silver, gold, cobalt-chromium and nickel-chromium alloys) whose surfaces have been treated by sandblasting only or by two methods of silica coating (Silicoater MD, Rocatec) or by painting with a primer (V-Primer). Results showed that, after storage in water, it is difficult to divide the studied alloys into a dental base alloys group and a noble alloys group. Therefore, the silica coating has significantly limited the propagation of fissures in water. Higher values of adherence energy were recorded with the Rocatec system except with the palladium alloy which must be treated with the Silicoater MD system. The treatment with V-Primer was sensitive to hydrolytic attack.

Correlation of topography to bond strength of etched ceramic.

PURPOSE: Bonding techniques are commonly used today to ensure the durability of porcelain laminate veneers and ceramic inlay-onlays, which are esthetically pleasing solutions to the problem of dental restoration. Acid etching and silanization of porcelain have been widely used to enhance the retention between bonding resins and ceramic restorations. The purpose of this study was to evaluate the effect of surface modifications with 10% hydrofluoric acid gel and a coupling agent (a dual component silane) on the bond strength of 2 dental feldspathic ceramics (GC and PVS) bonded with an unfilled resin (Super-Bond). MATERIALS AND METHODS: Eighty samples of GC and eighty samples of PVS were built for a mechanical study. Mechanical tests were conducted using a Lloyd T 6000 R tensile machine, which determined the bond strengths of the 2 ceramics after different surface treatments (etching or silanization). In the next part of the study, 10 surfaces of GC and 10 surfaces of PVS were studied with a scanning mechanical microscope to evaluate the action of hydrofluoric acid gel on the roughness of the 2 ceramics. RESULTS: Etching ceramic with hydrofluoric acid gel increased the developed surface of feldspathic ceramics, especially for PVS, but this treatment was not sufficient to obtain the highest shear bond strength. The highly positive influence of silanization was shown, particularly for GC ceramic bonded with an unfilled resin. CONCLUSION: Silane combined with the action of hydrofluoric acid gel is the most effective surface treatment for ceramic.

Water resistance of resin-bonded joints with time related to alloy surface treatment.

OBJECTIVES: This paper attempts to study the resistance of resin-bonded metallic joints to damage in water with time. METHODS: Unlike the shear or tensile test, a cleavage test (Double Cantilever Beam test) allows us to follow the crack propagation in water, according to the fracture mechanics concept. Moreover, it is possible to follow the kinetic degradation of the metal/resin interface because this test is not totally destructive to the assembly. We have worked on 18 batches according to the nature of the alloys (Pd, Pd-Ag, Au, Co-Cr and Ni-Cr) and the surface treatment (sandblasting, Silicoater MD, Rocatec, V-Primer). The crack length was measured over a period of 20 days. The results are expressed in terms of adherence energy. RESULTS: The adherence energy dramatically decreased with time in water. The slope of the regression straight line appears to be a good criterion for evaluating the durability of the alloy/adhesive interface. We have demonstrated the importance of silica coating and, especially, the effectiveness of the Rocatec system upon the degree of hydrolytic degradation, and have shown how the development of cracks depends upon surface treatment.

Surface energy of etched ceramic.

PURPOSE: In a previous article the authors examined the evolution of the bond strengths of 2 dental feldspathic ceramics. The objective of the present study was to evaluate the effect of surface modifications with hydrofluoric acid gel (concentration 10%) on the surface energy of 2 dental feldspathic ceramics (GC and PVS). MATERIALS AND METHODS: For an energy characterization, 30 samples of GC and 30 samples of PVS were built. This study comprised the measurement of contact angles to determine the work of adhesion (WA) of the 2 ceramics. The evolution of the work of adhesion depended on the action of the hydrofluoric acid gel on the roughness of the surface of the 2 ceramics. RESULTS: In a polished state PVS presented a higher work of adhesion than GC. Etching the ceramics with hydrofluoric acid gel increased the work of adhesion, especially for GC, but this treatment was not sufficient to obtain a high work of adhesion. CONCLUSION: Etching with hydrofluoric acid gel was not sufficient to raise the work of adhesion of the 2 ceramics. Silanization is preferable to etching.

Influence of the time-point of salivary contamination on dentin shear bond strength of 3 dentin adhesive systems.

PURPOSE: The aim of this study was to evaluate the influence of the duration of salivary contamination at different stages during the bonding procedures on shear bond strengths (SBS) of 3 dentin adhesives. MATERIALS AND METHODS: Flat human dentin surfaces were produced by wet grinding on SiC paper 800. The adhesives used were Syntac Sprint (SS) (Vivadent), One Step (OS) (Bisco), Clearfil Liner Bond 2 (LB2) (Kuraray). Three durations of contamination (3 s, 10 s, and 20 s) at 3 stages (before adhesive application, after its application, and after its polymerization). In all cases the saliva was not rinsed off. Twenty-seven groups of 10 samples were studied according to 3 adhesives, 3 stages, and 3 durations of contamination. For each adhesive, 1 control group, 3 groups with contamination before adhesive application, 3 groups with salivary contamination on the uncured adhesive, and 3 groups with contamination after polymerization (except for SS) were studied. Composite cylinders (Z100, 3M; 3 mm Ø, 5 mm high) were polymerized on the surfaces and stored in 37 degrees C H2O for 48 hours prior to shear bond testing (v = 5 mm/min). RESULTS: Anova and Scheffe tests showed that for the one-bottle systems tested, salivary contamination prior to adhesive application had no adverse effect on bonding efficacy, SBS decreased significantly when saliva contamination occurred after adhesive application. The self-etching primer tested was more tolerant to salivary contamination, except when the salivary contamination occurred before the polymerization of the adhesive. CONCLUSIONS: Salivary contamination does not have the same influence at different stages of the bonding process with modern adhesives. Pending better knowledge of the mechanisms involved in the influence of salivary contamination on bonded assemblies, it seems necessary to continue to recommend using the rubber dam in adhesive dentistry.

Electrochemical study of insulating properties of dental amalgam bonding polymers.

The standard techniques used for amalgam restorations often result in a lack of adhesion to mineralized dental tissues. The bonding of amalgam with polymer has been suggested to improve its adaptation to dental tissues. Moreover the polymer involved in the bonding should inhibit the corrosion and the diffusion of metallic ions. The aim of this study was to evaluate in vitro the capacity of bonded amalgam to prevent ionic diffusion and migration. In this respect, an original method employing electrochemical techniques was used to determine the leakage current of bonded amalgam restorations. The electrochemical behaviour of conventional and bonded amalgam restorations was compared using a potentiostat driven by a computerized system (Voltamaster, Radiometer Analytical) with software for specific applications such as chronoamperometry or cyclic voltammetry. Samples of recently extracted teeth of young patients were first examined, and then the results were checked by other experimental assays using protected and unprotected copper sticks. The measurements obtained with chronoamperometry (E = +300 mV/SCE) in Ringer's solution at 37 degrees C showed that after polarization for 30 h the oxidation current decreased threefold for bonded samples (10 microA cm(-2)) as compared with the unprotected samples (35 microA cm(-2)). These results, as well as those obtained with the copper wires, demonstrated that even with two layers of adhesive the bonded joint is permeable to ions probably as a result of the hydrophylic properties of HEMA, a component of the adhesive. However, using five layers of adhesive reduced the ionic current by a factor as large as 10(6).

Correlation between substratum roughness and wettability, cell adhesion, and cell migration.

Cell adhesion and spreading of chick embryo vascular and corneal explants grown on rough and smooth poly (methyl methacrylate) (PMMA) were analyzed to test the cell response specificity to substratum surface properties. Different degrees of roughness were obtained by sand-blasting PMMA with alumina grains. Hydrophilic and hydrophobic components of the surface free energy (SFE) were calculated according to Good-van Oss's model. Contact angles were determined using a computerized angle meter. The apolar component of the SFE gamma s(LW), increased with a slight roughness whereas the basic component, gamma s-, decreased. The acido-basic properties disappeared as roughness increased. Incubation of PMMA in culture medium, performed to test the influence if the biological environment, allowed surface adsorption of medium proteins which annihilated roughness effect and restored hydrophilic properties. An organotypic culture assay was carried out in an attempt to relate the biocompatibility to substratum surface state. Cell migration was calculated from the area of cell layer. Cellular adhesion was determined by measuring the kinetic of release of enzymatically dissociated cells. A slight roughness raised the migration are to an upper extent no matter which cell type. Enhancement of the cell adhesion potential was related to the degree of roughness and the hydrophobicity.

Bonding of resin cements to a metal substrate: influence of pretreatment on the adherence energy.

The adherence of resin cements to restoration as well as tooth structure is of prime importance for the longevity of cemented restorations. It was the aim of the study to investigate the effect of an acid and a base primer on (i) surface polarity of a nonprecious alloy and on (ii) adherence energy of resin cements bonded to the alloy. The beams were pretreated with a 3% acetone solution of either maleic acid or N,N-diethanol-p-toluidine, and the solvent evaporated. The polarity was determined by means of measurements of contact angles. The adherence energy was measured by means of the wedge test, according to which 2 beams were glued together with the resin cement. A wedge was introduced between the joined beams to create a fissure, and on the basis of the length of the fissure, the adherence energy was calculated. It was found that the polar component of the surface free energy of the alloy increased as a consequence of the pretreatments. The results also showed that the pretreatments gave rise to an increase in adherence energy of 11-15 J/m2, equivalent to relative increases of 22-54%. The observed increases in adherence energy may be due to an increase in polar interactions at the interface between adhesive and substrate.