Search results for "Post hoc"
showing 10 items of 27 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…
Evaluation of the effect of three innovative recyling methods on the shear bond strength of stainless steel brackets-an in vitro study
2016
Background Orthodontists are commonly faced with the decision of what to do with debonded or inaccurately positioned brackets. An economical option to this dilemma is to recycle the brackets. Many recycling methods have been proposed, but the optimal bond strength of these recycled brackets needs further evaluation. Objectives: To evaluate and compare the effect of three recycling methods: (i) Sandblasting (ii) Sandblasting / direct flaming (iii) Sandblasting /direct flaming /acid bath solution on shear bond strength (SBS) of stainless steel brackets. Material and Methods Eighty human premolars were bonded with premolar stainless steel brackets as per manufacturer’s instructions. The teeth …
Effect of different polishing techniques on surface roughness and bacterial adhesion of three glass ionomer-based restorative materials : in vitro st…
2020
Background Although many reports concluded that polishing of glass ionomers is crucial for smoother surface and limiting the adhesion of cariogenic bacteria, there is no specific surface treatment protocol recommended. A novel material in the same category was released recently claimed to have surface smoothness comparable to resin composite and bacterial adhesion less than other types of glass ionomers. In this study, different polishing systems were tested with three glass ionomers one of them is the novel material to find the most appropriate polishing protocol. Objectives: To evaluate and compare the surface roughness and bacterial adhesion to resin modified glass ionomer, bioactive ion…
Whitening toothpastes effect on nanoparticle resin composite roughness after a brushing challenge: An in vitro study
2019
Background Nowadays, the use of whitening toothpastes is a common habit, especially among young adults, due to aesthetic appeal. On the other hand, little is known regarding the effects of brushing with those newly dentifrices on wear properties of resin composites. Material and methods Thirty specimens of nanoparticle composite resin were fabricated and stored in distilled water for 24 h at 370C. After this, the roughness analysis was performed and submitted to the simulated brushing technique using three types of toothpastes: conventional (GI), and two with whitening effect (GII and GIII) for a period of 15 days, with 2 brushing sessions per day for 2 minutes each. The final surface rough…
Effect of pre-heating on the mechanical properties of silorane-based and methacrylate-based composites
2016
Background The use of composites in dental restoration has been commonly criticized, due to their underwhelming mechanical properties. This problem may be solved partially by preheating. The present research aims to determine the effect of preheating on the mechanical properties of two different classes of composites. Material and methods A Silorane-based (Silorane) and a Methacrylate-based (Z250) composite were preheated to different temperatures (25, 37, and 68 °C) and afterwards were tested with the appropriate devices for each testing protocol. The material's flexural strength, elastic modulus, and Vickers microhardness were evaluated. Two-way ANOVA, and Tukey's post hoc were used to an…
Effect of pH on compressive strength of some modification of mineral trioxide aggregate
2013
Objectives: Recently, it was shown that NanoMTA improved the setting time and promoted a better hydration process which prevents washout and the dislodgment of this novel biomaterial in comparison with WTMA. This study analyzed the compressive strength of ProRoot WMTA (Dentsply), a NanoWMTA (Kamal Asgar Research Center), and Bioaggregate (Innovative Bioceramix) after its exposure to a range of environmental pH conditions during hydration. Study Design: After mixing the cements under aseptic condition and based on the manufacturers' recommendations, the cements were condensed with moderate force using plugger into 9 × 6 mm split molds. Each type of cement was then randomly divided into three…
Effect of alkaline ph on sealing ability of white mineral trioxide aggregate
2011
Objectives: The aim of this study was to evaluate microleakage of white mineral trioxide aggregate (WMTA) after its exposure to a range of alkaline environments during hydration. Study Design: Seventy single-rooted teeth were divided into 4 experimental and 2 control groups. All the teeth were instrumented, and their apices were resected. Root-end cavities were filled with WMTA in the experimental groups. In the control groups, root-end cavities were not filled. Root-end fillings were exposed to alkaline environments with pH values of 7.4, 8.4, 9.4, or 10.4 for 3 days. Microleakage was evaluated by bovine serum albumin. Evaluations were carried out at 24-hour intervals for 80 days. Data wer…
Effects of different etching strategies on the microtensile repair bond strength of beautifil II giomer material
2018
Background Considering the differences in the filler particles between giomer and conventional composite resins and the importance of these fillers in the repair bond strength, the aim was to evaluate the effects of different etching strategies with phosphoric acid (PA) and hydrofluoric acid (HF) on the microtensile repair bond strength (µTRBS) of giomer. Material and Methods Ten giomer blocks were randomly assigned into 10: 1) control; 2) 37%PA-20s; 3) 3%HF-20s; 4) 3%HF-120s; 5) 9.6%HF-20s; 6) 9.6%HF-120s; 7) 37%PA-20s + 3%HF-120s; 8) 37%PA-20s + 9.6%HF-120s; 9) 3%HF-120s + 37%PA-20s; 10) 9.6%HF-120s + 37%PA-20s. In all groups, the One-Step Plus bonding system was applied and the new giome…
P123 Inhaled corticosteroid plus long-acting β2-agonist therapy is overused in the treatment of patients with chronic obstructive pulmonary disease: …
2015
Rationale Inhaled corticosteroid (ICS) plus long-acting β2-agonist (LABA) therapy is indicated for different patient groups with chronic obstructive pulmonary disease (COPD) in the USA and Europe. In the previous version of the Global initiative for chronic Obstructive Lung Disease (GOLD) recommendations, the use of ICS plus LABA therapy was restricted to patients with severe and very severe lung-function impairment and frequent exacerbations, with overtreatment in milder patient populations well documented. The current GOLD document recommends the use of ICS plus LABA maintenance therapy for patients in categories C and D. Methods We present post hoc analyses from the two pivotal 1-year TO…
Effect of two prophylaxis methods on adherence of Streptococcus mutans to microfilled composite resin and giomer surfaces
2010
Objectives: Surface attributes of a restoration play an important role in adherence of plaque bacteria. Prophylaxis methods may be involved in modification of or damaging the restoration surface. The aim of the present study was to evaluate the effect of two prophylaxis methods on adherence of Streptococcus mutans to the surface of two restorative materials. Study design: A total of 60 specimens were prepared from each material; a microfilled composite resin (HelioProgress) and a giomer (Beautifil II). For each material, the specimens were randomly divided into three groups (n=20). Group 1: no prophylaxis treatment (control); Group 2: prophylaxis with pumice and rubber cup; Group 3: prophyl…