All ETDs from UAB

Advisory Committee Chair

John O Burgess

Advisory Committee Members

Jack E Lemons

Deniz Cakir-Ustun

Mark S Litaker

Amjad Javed

Document Type

Thesis

Date of Award

2013

Degree Name by School

Master of Science (MS) School of Dentistry

Abstract

The success of ceramic restorations depends upon factors like the composite resin cement, the adhesive, cementation procedure and the substrate. With the introduction of newer ceramic and adhesive systems the factors that contribute to the most durable bond strength remains unclear. The objective of the study was to measure 24 hour and thermocycled shear bond strength of a composite to lithium disilicate glass ceramic with a universal single bottle adhesive. A combination of surface treatments of hydrofluoric acid, silane, salivary contamination and subsequent cleaning were also evaluated. Blocks of lithium disilicate (e.max CAD) were sectioned, polished with a rotational polishing device using a series of SiC disks and finished with 0.5µ Al2O3 slurry. All specimens were cleaned in an ultrasonic cleaner and were examined to ensure uniform surface finish. Surface treatments were done with concentrations of hydrofluoric acid and silane in various combinations followed by a bonding agent, according to the manufacturer's protocols. A cylinder of composite of diameter (1.5mm) was bonded to the cured adhesive and specimens were stored for 24 hours. In the next part of the study; saliva, collected from a single participant (2hrs postprandial), was pipetted onto the etched and silanated surfaces. Additionally some surfaces were cleaned using reagent alcohol or 35% phosphoric acid and the bonding agent applied, cured and composite cylinders bonded. For both the studies, the specimens were tested at 24 hours after bonding and the second group thermocycled for 10,000 cycles (5-50°C/15 sec dwell time) and debonded. For debonding the specimens were subjected to shear loading until failure using a universal testing machine and the shear bond strength calculated from the peak failure load. Contact angle measurements and scanning electron microscopy were used to analyze the effects of the treatments on the specimen surfaces. Data were analyzed with ANOVA and Tukey/Kramer post-hoc tests (p=0.005). Data were presented as estimated marginal means (least-square means).

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Dentistry Commons

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