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.
PURPOSE:The aims of this study were to evaluate the in vitro shear bond strength of the dentin-titanium interface mediated by Fuji Plus, a resin-modified glass-ionomer cement, applied in combination with several self-etching bonding systems, and to compare the values obtained with those of SuperBond, chosen as a reference luting agent.MATERIALS AND METHODS:The self-etching bonding systems used in combination with Fuji Plus were AdheSE, Xeno III, Clearfil SEBond, Unifil Bond, and an experimental self-etching bonding system comprising the sequential application of Xeno III and the bonding component of SE Bond. Two control groups were also tested: a negative control with Fuji Plus along with its conditioner (10% ferric chloride, 2% citric acid solution); and a positive control with the resin cement SuperBond. One hundred five human molars were used to prepare seven groups of fifteen samples each. The samples were tested in shear after 7-day storage at 100% relative humidity and 37 degrees C.RESULTS AND CONCLUSION:Three of the tested combinations of self-etching bonding systems with Fuji Plus significantly improved in comparison with the negative control group, from 9% to 44%. The self-etching bonding systems obtained using Fuji Plus in combination with Clearfil SEBond, Unifil Bond, and the experimental system were not different from those obtained with SuperBond.
PURPOSE To compare the penetration and the imperviousness of two pit and fissure sealants according to surface treatments involving different cleaning procedures with or without subsequent acid etching. MATERIALS AND METHODS Two sealants were used: a resin-based sealant (Concise White Sealant) and a compomer-based material (Dyract Seal) coupled with an enamel-dentin bonding agent (Dyract Seal and Prime&Bond NT). Extracted molars (n = 120) were randomly divided into 12 groups: 4 control and 8 experimental groups that received different surface treatments. Pumice, alumina, or bicarbonate was used to clean the surfaces. Phosphoric acid or non-rinse conditioner was used as acid etching agents. After sealing, the Concise White Sealant groups were directly thermocycled for 1800 cycles, while the Dyract Seal groups were stored in water for one month before thermocycling. After apex sealing and varnish coating, the fillings were stained with silver nitrate and embedded. Three to 6 cross sections of 200 microm each were made per sample to assess both sealant penetration (% of the length of the fissure) and the imperviousness of the seal (scores method). RESULTS Concise White Sealant achieves a better enamel sealing than Dyract Seal when the teeth are treated with air abrasion or air polishing followed by etching. Acid etching is essential for good sealing, whatever the material and cleaning technique tested. Only the combination of air abrasion and phosphoric acid etching yielded a leak-free joint. CONCLUSION This study clearly shows that penetration and sealing are two different phenomena. Ideally, an efficient sealant must have a good sealing ability and a high rate of infiltration as well, but these two properties probably do not have the same clinical relevance. The imperviousness of the seal remains the most important requirement.
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(R)) was used to measure the contact angle (theta) kinetics of a reference liquid (pure H2O) 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 dryers 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. (C) 2002 Academy of Dental Materials. Published by Elsevier Science Ltd. All rights reserved.
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.
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.
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.
La technique des bridges colles telle qu'elle a ete initialement concue par ROCHETTE et modifiee plus tard par l'ecole de Maryland, est nettement moins mutilante que les bridges conventionnels. En theorie, cette technique presente un bon ratio mutilation/efficacite. Le but de ce travail est de passer en revue les principaux parametres interactifs influencant la longevite de ces restaurations collees. Ces facteurs sont : position des dents mobiles, choix et preparation des piliers, conception et ajustage de l'armature, performances mecaniques des alliages coules, nature des traitements de surface, selection d'un ciment de collage et enfin, etapes cliniques de collage. Une bonne maitrise de ces parametres peut nettement ameliorer la longevite des bridges colles.
Literature data onadherence tests ofdentin-bonding systems (DBS)maydiffer widely, evenforthesame DBS.Theproblem ofbondtesting isthat materials areseldomcomparedwitha standard, and experimental conditions often vary. We sought to identify theparameters thatinfluence this variability. Usinginclusion andexclusion criteria, weconducted ameta-analytical reviewof75 articles, published between 1992and1996inSCI reviews, that givebondstrength data for15dentin- bonding agents oftheso-called third andfourth generations. Seventeen selected parameters were classified into four groups: GroupA includes factors related tothedentin substrate (i.e., nature ofteeth); groupB,composite andbonding area(i.e.,