Search results for "Universal testing machine"
showing 10 items of 69 documents
Fracture resistance of tooth restored with four glass fiber post systems of varying surface geometries-An in vitro study
2016
Background The purpose of this study was to relate the fracture resistance of endodontically treated teeth in relation to post geometry. Material and methods Forty single rooted mandibular premolars were instrumented by step - back technique and obturated by lateral condensation. Forty teeth were randomly divided into four groups: Reforpost glass fiber X-ray®, RelyX®, Exacto conical® and Parapost Fiber Lux®. The post spaces were prepared using respective drills and luted. The core build up was done and metal crowns were luted. Fracture resistance was determined in universal testing machine. The statistical analysis was done using one way ANOVA and post hoc Tukey Kramer test. Results The tee…
Retention strength of ball-attachment titanium post for removable partial denture or overdenture
2020
Aim: To evaluate the retention of an endodontic titanium post with a spherical head for removable partial denture or overdenture attachment according to surface treatment type. Methods: Sixty healthy single-rooted teeth, sectioned at the enamel/cementum junction, were treated endodontically and steadily fixed in the embedding acrylic resin. The titanium posts were subdivided into four groups: control, no surface treatment (Ctrl); posts with macro-retentive grooves (MR); air abrasion of the post surface (AB); and posts with macro-retentive grooves and air abrasion of the post surface (MR+AB). The posts were luted in the root canal using self-adhesive dual resin cement. Pull-out testing was p…
An Ex-vivo Shear and tensile bond strengths of orthodontic molar tubes bonded using different techniques
2017
Background Molar bonding procedures need continuous improvement to be widely accepted clinically and eventually replace molar bands. Material and methods The purpose of this study was to determine the effects of enamel micro-abrasion and silane coating of the base of molar tubes on shear and tensile bond strengths of orthodontic molar tubes. A total of 200 third molars were randomly allocated into five groups of 40 teeth as follows: group 1: molar tubes bonded to etched teeth (37% phosphoric acid gel; control group); group 2: molar tubes bonded to etched teeth (37% phosphoric acid) with the addition of silane to the base of molar tubes; group 3: molar tubes bonded to teeth pre-treated with …
Effects of different powder to liquid ratios on the push out bond strength of CEM cement on simulated perforations in the furcal area
2017
Background Proper bond strength to dentin is one of the properties of biomaterials used for therapeutic purposes such as repair of furcal perforations. The aim of the present study to evaluate the effects of different powder to liquid ratios of Calcium-enriched mixture (CEM) on the push-out bond strengths in simulated perforations in the furcal area and compare it with Mineral trioxide aggregate (MTA). Material and Methods Furcal perforations, measuring 1.3 mm in diameter and 2 mm in height, were prepared in 120 mandibular first molars. Then the samples were randomly assigned to two groups (n=60). MTA and CEM cement were used for the repair of perforations in groups 1 and 2, respectively. E…
Influence of simplified, higher-concentrated sodium ascorbate application protocols on bond strength of bleached enamel
2019
Background Bleaching procedures performed before restorative procedures, due to the oxygen released, affects the quality of bonding restorations. The application of an lower-concentrated antioxidant for one-hour or more can reversal the compromised bonding to bleached enamel, but it was not effective according to the bleaching concentrations applied. The aim of the present study was to evaluate simplified protocol of higher-concentrated sodium ascorbate (35%SA) in bond strength values of enamel bleached with 10%, 16%, 22% carbamide peroxide (CP) or 35% hydrogen peroxide (HP). Material and Methods Three hundred and forty enamel surfaces of 85 human third molars were used, divided into 17 gro…
Bond strength and elemental analysis of oxidized dentin bonded to resin modified glass ionomer based restorative material
2019
Background This study aimed to investigate the influence of hesperidin application on the bonding of resin-modified glass ionomer-based restorative material to dentin treated with oxygen-induced endodontic irrigants. Material and Methods One hundred human permanent molars were categorized into five groups (n= 20/group), treated with various irrigants as follows: Group C; distilled water (control group), Group SH; 5.25% NaOCl, Group SH+H; 5.25% NaOCl + 5 % hesperidin, Group HP; 10% H2O2, Group HP+H; 10% H2O2 + 5 % hesperidin. Specimens were bonded with RMGI based restorative material. For each group, half of the specimens were evaluated for µSBS by a universal testing machine and the other h…
Assessment of shear bond strength and microleakage of fissure sealant following enamel deproteinization : an in vitro study
2020
Background To evaluate the effect of two different deproteinizing agents (5.25% sodium hypochlorite and Papacarie®) prior to acid etching on the shear bond strength and microleakage of a fissure sealant material. Material and methods A total of 123 extracted noncarious human third molar teeth were randomly divided into three groups for each test: acid etching alone (control) (C), sodium hypochlorite (NaOCl), and Papacarie Duo® (PC). The shear bond strength tests were performed using a universal testing machine, and microleakage was evaluated using a dye penetration method. Results The mean shear bond strength values obtained in Group C were significantly lower than those of Group NaOCl and …
Influence of the volume of restorative material on the concentration of stresses in the restorative interface.
2020
Background To evaluate the microtensile strength in the adhesive interface depending on the volume of the composite resin used to restore class I cavities. Material and Methods Forty-eight human third molars received a standardized class I cavity preparation and they were separated into six experimental groups: G1 - single-bottle adhesive system; G2 - bonding system with load; G3 - single-bottle adhesive associated with low-viscosity composite resin; G4 - loaded adhesive associated with low-viscosity composite; G5 - resin-modified glass ionomer associated with single-bottle adhesive; and G6 - resin-modified glass ionomer associated with loaded adhesive. All cavities were restored with a uni…
Durability of solvent-free one-step self-etch adhesive under simulated intrapulpal pressure
2015
Background: There are different solvents presented in simplified adhesives. Bond-1 SF has been developed, which contains neither water nor organic solvents, in order to eliminate technical issues in terms of evaporation of solvents and concerns for the durability of resin-dentin bond. Thus this study was conducted to evaluate the microtensile bond strength (μTBS) of solvent-free and ethanol-based one-step self-etch adhesives to dentin under simulated intrapulpal pressure (IPP). Material and Methods: Occlusal surfaces of human molars were prepared to expose mid-dentin depth. Bond-1SF Solvent-Free SE [SF] and Adper TM easy one [AE] adhesives were applied on dentin specimens. Resin composite b…
The effect of bacterial cellulose nanocrystals on the shear bond strength of resin modified glass ionomer cement to dentin
2020
Background The present study aimed to investigate the effect of bacterial cellulose nanocrystals (BCNC) on the shear bond strength (SBS) of resin modified glass ionomer cement (RMGIC) to dentin. Material and Methods A total of 48 freshly extracted intact third molars were randomly divided into four main groups with three different concentrations (0.3%, 0.5% and 1% wt) of BCNC with RMGIC and control group without BCNC. These specimens were kept in distilled water at 37° C for 24h. Shear bond strength was examined, using the universal testing machine. Kruskal-Wallis test and Dunn`s post-hoc test were applied for analysis of data. P<0.05 was considered as the level of significance. Results The…