Dental Materials Commons^™

Effect Of Nanofiller Coating And Loading On Facial Elastomer Physical Properties, Rahmi K. Aulia

Theses & Dissertations

Current materials used for facial prostheses are far from being desirable, and improved properties with “skin-like” feel are needed. This study evaluates property changes induced by sequential additions of uncoated and hydrophobic-coated nano-SiO₂ to polydimethylsiloxane (PDMS) and compares them with those measured for conventional submicron SiO₂-filled materials. Each filler type was sequentially added to vinyl-terminated PDMS at 0%, 0.5%, 5%, 10%, and 15% by weight. Tensile, tear, Durometer hardness, translucency and viscoelastic properties were evaluated, with hardness and translucency also evaluated following 3000 hours of outdoor weathering. Results demonstrated that 15% coated nano-SiO₂-filled PDMS materials …

The Effectiveness Of Resin-Modified Glass Ionomer Varnish In Preventing White Spot Lesions During Fixed Appliance Orthodontic Therapy: An In Vitro Study, Bradley Herman

Theses & Dissertations

The purpose of this investigation was to evaluate the efficacy of a glass ionomer varnish in preventing demineralization of enamel adjacent to and some distance away from an orthodontic bracket. Forty extracted human molars were divided into four different treatment groups (varnish in distilled water, varnish in acetic acid, enamel in acetic acid, and enamel in distilled water). Two 3 x 3 mm graphite windows were drawn on the tooth, one adjacent to the bracket and one 3 mm away from the first window, indicating the scanning area. Varnish was applied to the teeth in the varnish groups and all …

Effects Of Flash-Free Technique On Plaque Retention, White Spot Lesions, And Bracket Failure: A Randomized Clinical Trial, Payam Ishani Afousi

Theses & Dissertations

A side effect of orthodontic treatment is the development of white spot lesions (WSLs). This thesis attempted to evaluate the effects of the use of APC™ Flash-Free (FF) and conventional adhesives in bonding of orthodontic brackets on plaque formation and retention, WSL development, and bracket failure in-vivo. This was accomplished by collecting plaque samples from around orthodontic appliances and analyzing them using ATP-driven bioluminescence; scanning enamel surfaces using the Canary System™ to evaluate WSL development, and counting the number of spontaneous debonding of brackets of the 4 maxillary incisors in the first 6 months of treatment. It was found …

Color Stability, Physical Properties And Antifungal Effects Of Zro2 And Tio2 Nanoparticle Additions To Pigmented Polydimethylsiloxanes, Mazen Alkahtany

Theses & Dissertations

Introduction: Color changes, physical degradation and fungal infections are potential challenges to the longevity of polydimethylsiloxane (PDMS) elastomers. The purpose of this study was to evaluate potential improvements in color change, physical properties and anti fungal properties of PDMS loaded with TiO2 and ZrO2 nanoparticles.

Methods: 1% weight of 40 nm or 200 nm diameter TiO2 or ZrO2 nanoparticles were mixed into PDMS with 2% functional intrinsic yellow pigment and polymerized. Control materials contained 13% weight 200 nm silica. Samples were exposed to either 3000 hours of UVB radiation (200 μW/cm2) or darkness. Color parameters L*a*b* and ΔE*, ultimate tensile …