Effect of insertion method on knoop hardness of high viscous glass ionomer cements.

The aim of this study was to assess the Knoop hardness of three high viscous glass ionomer cements: G1 - Ketac Molar; G2 - Ketac Molar Easymix (3M ESPE) and G3 - Magic Glass ART (Vigodent). As a parallel goal, three different methods for insertion of Ketac Molar Easymix were tested: G4 - conventional spatula; G5 - commercial syringe (Centrix) and G6 - low-cost syringe. Ten specimens of each group were prepared and the Knoop hardness was determined 5 times on each specimen with a HM-124 hardness machine (25 g/30 s dwell time) after 24 h, 1 and 2 weeks.

Polymerization contraction stress in dentin adhesives bonded to dentin and enamel.

Objective: In a previous study on of polymerization contraction stress determinations of adhesives bonded to dentin a continuous decline of stress was observed after the adhesives had been light-cured. The decline was ascribed to stress relief caused by diffusion into the adhesive layer of water and/or solvents, left in the impregnated dentin surface after drying and/or evaporation in the application procedure. The purpose of the present study was to test the hypothesis that the contraction stress of adhesives bonded to enamel will not decline after light-curing, based on the assumption that water and/or solvents are more efficiently removed from impregnated enamel surfaces in the drying and/or evaporation step.

Effect of pre-etching enamel on fatigue of self-etch adhesive bonds.

Objective: A previous study found that the shear bond strength (SBS) to bovine enamel for the self-etching adhesive Adper Prompt-L-Pop (PLP) was 75% of that found with the etch-and-rinse material SingleBond, while the comparative value for the shear fatigue limit (SFL) was only 58% at 10(5) load cycles. Resin penetration into the enamel surface was substantially less for PLP but it was not conclusive that this was the reason for the lower results cited above. The objective of this study was to determine if pre-etching enamel would substantially improve the SBS and SFL of the PLP adhesive over those found in the previous study.

Contraction stress and bond strength to dentinfor compatible and incompatible combinations of bonding systems and chemical and light-cured core build-up resin composites.

Objective: Recent studies have shown that adhesives containing acidic monomers combined with composites can adversely effect the polymerization reaction producing low bond strengths. This phenomenon may also occur in making composite build-ups, jeopardizing one of the key factors for a successful core build-up restoration. The aim of this study was to investigate the contraction stress development and bond strength to dentin of core build-up resin composites combined with adhesives of various acidities.

Fatigue testing of enamel bonds with self-etch and total-etch adhesive systems.

Objective: Etching of enamel by self-etching adhesive systems is not as pronounced as with phosphoric acid employed with most total-etch adhesive systems. This may result in differences in the effectiveness of the bonds for the two types of systems. The aim of this study was to compare two such systems by bond strength and fatigue testing.

The effects of common errors on sealing ability of total-etch adhesives.

Objectives: This study evaluated the effect of errors commonly made in using total-etch adhesives, on the resulting bond strength, fluid movement and nanoleakage of resin dentin bonds.

Methods: Two total-etch adhesives were used for bonding to dentin according to the manufacturers' recommendations, with meticulous solvent evaporation (control), or with the introduction of common bonding errors-wet bonding without solvent evaporation (no evaporation), and dry bonding.

Results: The 24-hour bond strength of the control was significantly higher than the other groups (p <0.

Early and long-term wear of 'fast-set' conventional glass-ionomer cements.

Objective: Fast setting high viscous glass-ionomer cements have been introduced to reach the set state sooner and to improve early mechanical properties. The aim of this study was to investigate whether 'fast-set' cements have improved the early three-body wear.

Method: The three-body wear of four glass-ionomer cements was measured after 1, 4, 7, 30, 90, and 365 days.

Effect of conditioning time of self-etching primers on dentin bond strength of three adhesive resin cements.

Objectives: To evaluate the effect of increasing the dentin conditioning time with self-etching primers of different aggressiveness (pH) on the microtensile bond strength (muTBS) of three resin cements.

Materials And Methods: Pre-cured composite blocks were cemented with M-Bond, Bistite II DC, or Panavia F to flat occlusal dentin surfaces of human third molars, which were conditioned with M-Bond or Bistite II-primer for 30, 60 or 180 s or with Panavia-primer for 60 or 180 s. Each dentin-composite block assembly (four in each group) was longitudinally sectioned to obtain 1x1 mm microbars and tested for the muTBS.

Influence of fatigue loading on the performance of adhesive and nonadhesive luting cements for cast post-and-core buildups in maxillary premolars.

Purpose: This study evaluated the influence of fatigue loading on the performance of an adhesive and a nonadhesive cement for cast post-and-core restorations in maxillary premolars.

Materials And Methods: The adhesive cement used was Panavia 21, a resin-based composite cement, and the nonadhesive cement was PhosphaCem/C, a zinc-oxy-phosphate cement. The coronal sections of single-rooted human maxillary premolars were removed at the level of the proximal CEJ.

In situ transformation of glass-ionomer into an enamel-like material.

Purpose: To assess the nature of clinically detectable alterations in glass-ionomer after long-term clinical service.

Methods: In addition to clinical macro pictures, SEM was carried out on replicas and on two sectioned primary molars SEM-EDAX analysis was performed to determine chemical transformation in the glass-ionomer. Also with SEM-EDAX, the composition was determined of a partially removed half-year old sealant.

The effect of adhesives with various degrees of hydrophilicity on resin ceramic bond durability.

Objectives: To investigate the role of different acid surface-treatments and hydrophilic and hydrophobic bonding agents on resin ceramic bond durability.

Methods: Two resin cements, Tetric Flow and Nexus 2, were applied to CAD/CAM Cerec Vitablocs with six bonding strategies: (1) HF-etching and silanization, (2) HF-etching, silanization and application of a hydrophilic bonding agent, (3) HF-etching, silanization and application of a hydrophobic bonding agent, (4) H3PO4-treatment and silanization, (5) H3PO4-treatment, silanization and application of a hydrophilic bonding agent, and (6) H3PO4-treatment, silanization and application of a hydrophobic bonding agent. The hydrophilic agents were Syntac Single-Component and OptiBond Solo Plus.

Effect of dentin perfusion on the sealing ability and microtensile bond strengths of a total-etch versus an all-in-one adhesive.

Objectives: To test the null hypothesis that perfusion of dentin has no effect on the sealing or bond strength in Class V resin composite restorations using a two-step total-etch (Scotchbond 1), or a one-step self-etch (all-in-one) (Prompt L-Pop) adhesive.

Methods: Dentin permeability in Class V cavity preparations cut into extracted human third molars was measured in a fluid transport setup. Resin composites were placed using either Scotchbond 1, or Prompt L-Pop with or without dentin perfusion at 1.

Curing efficiency and heat generation of various resin composites cured with high-intensity halogen lights.

The objective of this study was to assess the curing efficiency and heat generation of two high-intensity halogen lamps, the Astralis 10 HIP (1100 mW cm(-2)), and Optilux 501 Boost (1000 mW cm(-2)) in curing three resin composites (InTen-S, Tetric Ceram, and Filtek Z250). It was expected that the two lamps, having similar irradiance would give rise to the same curing efficiency and heat generation. The curing efficiency was evaluated by Vickers hardness and depth of cure measurements.

Microtensile bond strength testing of luting cements to prefabricated CAD/CAM ceramic and composite blocks.

Objectives: To investigate the Microtensile bond strength (microTBS) and failure mode of resin cements bonded to composite and ceramic CAD/CAM blocks following various surface treatments.

Methods: Paradigm composite blocks and Cerec Vitablocs received three surface treatments following the control treatment of surface grinding with 600 SiC grit. (1) Application of adhesive resin (Adh), (2) etching with hydrofluoric acid and silanization (HF+S) or (3) combination of the previous two treatments (HF+S+Adh).