Shelf life effects on the bond strength and microhardness of self-adhesive resin cements.

Background: Among the main advantages of self-adhesive resin cements comprise good aesthetics, strong restoration-tooth bond and biocompatibility. However, some disadvantages, such as high viscosity level, color limitation and short shelf life should be mentioned. Thus, the aim of the current study was to assess bond strength between fiberglass post and root dentin in teeth subjected to self-adhesive resin cements with expired shelf life and hardness.

Evaluating changes in the color and luminosity of dental enamel after orthodontic treatment: A clinical study.

The aims of this clinical study were to evaluate the Color change - ΔE (based on spectrophotometry and visual analysis) and luminosity - L* (based on spectrophotometry) of dental enamel surface (after orthodontic treatment) around the area where orthodontic brackets were fixed, based on different cementing materials such as a resin (R group) and resin-modified glass ionomer cement (RMGIC group). The split-mouth study initially comprised 14 patients. Orthodontic brackets were fixed to the upper central incisors with resin or RMGIC.

Evaluation of Removal Force in Prosthetic Components of Morse Taper Dental Implants.

The longevity of prosthetic rehabilitation is determined by the stability of the implant and abutment interfaces. True morse taper connections on dental restorations have been effective, however activation force still empirical. This work compared the activation strength and internal contact of Morse taper system according to the removal force.

Experimental resin-based dual-cured calcium aluminate and calcium titanate materials for vital pulp therapy.

This paper evaluates the physicochemical and biological properties of experimental resin-based dual-cured calcium aluminate (CA) and calcium titanate (CTi) materials for vital pulp therapy (VPT). The experimental dual-cured materials were obtained as two pastes: a) Bis-EMA 10, PEG 400, DHEPT, EDAB, camphorquinone, and butylated hydroxytoluene; and b) fluoride ytterbium, Bis-EMA 10, Bis-EMA 30, benzoyl peroxide, and butylated hydroxytoluene. The materials were divided into six groups based on the added calcium component: MTA (MTA®, Angelus); CLQ (Clinker-Fillapex®, Angelus); CA (calcined at ,1200°C in pastes a and b); CA800 (calcined at 800°C in paste a); CA1200 (calcined at 1,200°C in paste a); and CTi (paste a).

Influence of resin cement and thermocycling on milled lithium disilicate ceramic microshear bond strength.

The aim of this study was to compare the microshear bond strength of different resin cements to CAD/CAM-created lithium disilicate ceramics after 24 hours and after 1 year (10,000 thermocycles). Forty (40) ceramic bars were subjected to pretreatment comprising airborne abrasion with aluminum oxide particles, etching with 10% hydrofluoric acid and Monobond N application. Bars were divided into 4 groups (n = 10), based on cement type: light-cured Variolink Esthetic LC (VLC) and dual-cured Variolink N (VN) at two different times: after 24 hours and after 1 year.

Evaluation of enamel roughness after the removal of brackets bonded with different materials: In vivo study.

The aims of this in vivo study were to evaluate the effect of bonding with resin-modified glass ionomer cement (RMGIC) and to assess enamel surface roughness before and after the removal of brackets bonded with composite or RMGIC from the maxillary central incisors. Fifteen orthodontic patients were selected for the study. For each patient, the teeth were rinsed and dried, and brackets were bonded with composite (Transbond XT) and RMGIC (Vitremer Core Buildup/Restorative).

Photoelastic stress analysis of different types of anterior teeth splints.

Background/aims: Traumatic dental injuries are highly prevalent and are considered an important health problem. The aim of this study was to evaluate the in vitro stress distribution around simulated traumatized teeth subjected to different types of splints by photoelastic analysis.

Materials And Methods: For each group, five models of maxillary and mandibular arches were made in photoelastic resin using prefabricated teeth models, which were fixed and adjusted in a semi-adjustable articulator.

Analysis of Molecular Changes Induced By Mineral Trioxide Aggregate On sPLA2.

The aim of this study was to analyze the effects of MTA on the structure and enzymatic activity of sPLA2 in order to provide subsidies for improvement in the formulation of the product. MTA powder was incubated for 60 min in the presence of sPLA2 and was analyzed by chromatography, electrospray mass (ESI-MS) and small-angle X-ray scattering (SAXS). It was find that the elution profile, retention time, and fragmentation of sPLA2 were altered after treatment with MTA.

Evaluation of bond strength durability on bleached human dentin.

This study evaluated the effect of aging on the microtensile bond strength (μTBS) between composite resin and human dentin bleached with 35% hydrogen peroxide (HP) or 10% carbamide peroxide (CP). Thirty intact extracted third molars were selected for the study. After the dentin surface was exposed, the smear layer was abraded with silicon carbide paper to ensure standardization.

Influence of chloramine-T disinfection on elastomeric impression stability.

Objective: The aim of this study was to evaluate the stability of elastomer through detail reproduction and its dimensional stability (DS) after disinfection with 0.2% chloramine-T.

Materials And Methods: The elastomeric impression dental materials used in this study were polydimethylsiloxane (Oranwash L), polyvinyl siloxane (Express), polysulfide (Permlastic), and polyether (Impregum Soft).

Microtensile Bond Strength and Microhardness of Composite Resin Restorations Using a Sonic-Resin Placement System.

The aim of this study was to evaluate the efficacy of applying sonic energy on microtensile bond strength and microhardness after the restoration process. A total of 40 human third molars were extracted. Class II cavities were prepared and restored with composite SonicFill or Filtek Z350 XT with and without the application of sonic energy.

Root canal treatment of a fused mandibular incisor using cone-beam computed tomography as a diagnostic aid.

Tooth fusion consists of the union of crowns by the enamel and/or dentin. We describe a case of a patient who presented with a fistula in the apical portion of teeth 32 and 33. Clinically, tooth 32 showed increased crown width in relation to other teeth in the same arch.

Surface detail reproduction and dimensional accuracy of molds: influence of disinfectant solutions and elastomeric impression materials.

This study compared the surface detail reproduction and dimensional accuracy of molds after disinfection using 2% sodium hypochlorite, 2% chlorhexidine digluconate or 0.2% peracetic acid to those of molds that were not disinfected, for four elastomeric impression materials: polysulfide (Light Bodied Permlastic), polyether (Impregum Soft), polydimethylsiloxane (Oranwash L) andpolyvinylsiloxane (Aquasil Ultra LV). The molds were prepared on a matrix by applying pressure, using a perforated metal tray.

Influence of Surface Treatments and Adhesive Systems on Lithium Disilicate Microshear Bond Strength.

The purpose of this study was to evaluate the microshear bond strength of ceramic prosthetic structures reinforced by lithium disilicate cemented with resin cement under conditions of different surface treatments and adhesive systems. Seventy-two rectangular blocks of lithium disilicate (6.5 mm long × 5 mm wide × 1 mm thick) were fabricated, air abraded with 50-μm Al2O3 particles and divided into six groups (n=12) depending on the surface pretreatments.

The influence of concentration of HEMA on degree of conversion and cytotoxicity of a dental bonding resin.

Background: This study evaluated the influence of 2-hydroxyethyl methacrylate (HEMA) on the degree of conversion (DC) and cytotoxicity of a dental bonding resin (DBR).

Methods: A monomer mixture based on 61.9 wt% of bisphenol A glycidyl methacrylate (Bis-GMA), 36.

Push-Out Bond Strength of Restorations with Bulk-Fill, Flow, and Conventional Resin Composites.

The aim of this study was to evaluate the bond strengths of composite restorations made with different filler amounts and resin composites that were photoactivated using a light-emitting diode (LED). Thirty bovine incisors were selected, and a conical cavity was prepared in the facial surface of each tooth. All preparations were etched with Scotchbond Etching Gel, the Adper Scotchbond Multipurpose Plus adhesive system was applied followed by photoactivation, and the cavities were filled with a single increment of Filtek Z350 XT, Filtek Z350 XT Flow, or bulk-fill X-tra fil resin composite (n = 10) followed by photoactivation.

Stress generated by customized glass fiber posts and other types by photoelastic analysis.

Endodontic posts are necessary to provide adequate retention and support when no sufficient remaining structure is available to retain the core. There are different materials and techniques to construct post-and-core, but there is no consensus about which one promotes better stress distribution on the remaining tooth structure. This study aimed to quantify and evaluate the distribution of stress in the root produced by customized glass fiber posts compared to different endodontic posts.

Effect of sodium hypochlorite and peracetic acid on the surface roughness of acrylic resin polymerized by heated water for short and long cycles.

Objective: To evaluate the surface roughness of acrylic resin submitted to chemical disinfection via 1% sodium hypochlorite (NaClO) or 1% peracetic acid (C2H4O3).

Materials And Methods: The disc-shaped resin specimens (30 mm diameter ×4 mm height) were polymerized by heated water using two cycles (short cycle: 1 h at 74°C and 30 min at 100°C; conventional long cycle: 9 h at 74°C). The release of substances by these specimens in water solution was also quantified.

Comparison of frictional resistance between self-ligating and conventional brackets tied with elastomeric and metal ligature in orthodontic archwires.

Objective: To compare the frictional resistance between self-ligating and conventional brackets tied to different types of wire.

Material And Methods: Abzil Kirium Capelozza (Pattern I) and Easy Clip (Roth prescription) incisor brackets were used. An elastomeric ligature or a 0.

Evaluation of contraction stress, conversion degree, and cross-link density in low-shrinkage composites.

Objective: The contraction stress, degree of conversion, and cross-link density (CLD) of the Venus Diamond (low-shrinkage), Filtek P90 (low-shrinkage) and Filtek Z350 XT composites were evaluated after photopolymerization by quartz tungsten halogen or light-emitting diode light curing units.

Materials And Methods: Contraction stress measurements were performed on 60 samples fabricated in rings of photoelastic resin. The adhesive was applied and photoactivated, followed by insertion and photoactivation of the composites.

Effect of different surface penetrating sealants on the roughness of a nanofiller composite resin.

This study evaluated the effectiveness of different sealants applied to a nanofiller composite resin. Forty specimens of Filtek Z-350 were obtained after inserting the material in a 6x3 mm stainless steel mold followed by light activation for 20 s. The groups were divided (n=10) according to the surface treatment applied: Control group (no surface treatment), Fortify, Fortify Plus and Biscover LV.

Evaluation of the coefficient of thermal expansion of human and bovine dentin by thermomechanical analysis.

The mismatch of thermal expansion and contraction between restorative materials and tooth may cause stresses at their interface, which may lead to microleakage. The present work compared the coefficient of thermal expansion (CTE) with the thermomechanical behavior of human and bovine teeth and determined if the CTE is a suitable parameter to describe tooth behavior. Fifteen human third molar and 15 bovine incisor tooth slices (6×5×2 mm) were allocated to 3 groups according to the test environment: G1 - room condition, G2 - 100% humidity, G3 - desiccated and tested in dry condition.

Bond strength of HEMA-containing versus HEMA-free self-etch adhesive systems to dentin.

This study analyzed the bond strength (BS) of HEMA versus HEMA-free self-etch adhesive systems to dentin. The occlusal surface of 20 third molars was removed and the dentin was abraded with 600-grit silicon carbide paper. The teeth were randomly assigned to 4 groups (n = 5) and restored with GO, Adper SE Plus, OptiBond All-In-One, and Clearfil 3S Bond adhesive systems and Filtek Z350 composite.

Photoelastic analysis of stress generated by a silorane-based restoration system.

Silorane-based composite, an epoxy material, was marketed as promising less polymerization contraction than conventional restorative materials. The aim of this study was to evaluate, by means of photoelasticity, the polymerization stress generated by a silorane-based composite. Thirty photoelastic rings with orifices measuring 5 mm (d) × 3 mm (h) were prepared and divided into 6 groups (n = 5) according to the material tested.

Interproximal space recovery using an orthodontic elastic separator before prosthetic restoration: a case report.

The presence of a dental contact point is essential to maintain normal occlusion and to preserve the health of periodontal structures. Occasionally dental caries could compromise the interproximal contact point, leading to migration of the adjacent teeth with consequent retention of food, gingival inflammation, pocket formation, bone loss and dental mobility. In order to achieve an adequate restorative treatment, reestablishment of interproximal space is necessary.