Publications by authors named "Dorien Lefever"
The aim of the study was to evaluate the influence of composite type and adhesive system on the quality of marginal adaptation in standardized Class V cavities before and after thermo-mechanical loading (TML). The cavities were restored using different combinations of three adhesive systems [(Silorane System Adhesive (SSA), Clearfil S Bond (S3), G-Bond (G-B)] and two resin composite materials (Filtek Silorane, Clearfil AP-X). Six groups (n = 10): Group A (SSA-Primer + SSA-Bond, Filtek Silorane), Group B (SSA-Primer + SSA-Bond, Clearfil AP-X), Group C (S3 + SSA-Bond, Filtek Silorane), Group D (S3 + SSA-Bond, Clearfil AP-X), Group E (G-B + SSA-Bond, Filtek Silorane) and Group F (G-B + SSA-Bond, Clearfil AP-X) were defined.
View Article and Find Full Text PDFPurpose: To determine changes in surface gloss of different composite materials after laboratory toothbrushing simulation.
Methods: 40 specimens were fabricated for each material (Filtek Supreme XTE, Renamel, Empress Direct, Gradia Direct, Edelweiss, G-aenial, Venus Pearl and Venus Diamond) and polished with 120-, 220-, 500-, 1200-, 2400- and 4000- grit SiC abrasive paper, respectively. Gloss measurements were made with a glossmeter prior to testing procedures and then subjected to simulated toothbrushing for 5, 15, 30 and 60 minutes by means of an electrical toothbrush with a pressure of 2N while being immersed in a 50 RDA toothpaste slurry.
Objectives: To determine the marginal adaptation of bulk-fill composites in class II MO cavities.
Methods: Standardized class II MO cavities with bevelled enamel margins were prepared in 40 extracted human molars. The teeth were randomly assigned to one of the five experimental groups (n=8).
The aim of this study was to evaluate the influence of different backgrounds on spectrophotometric colour values of natural teeth. Twenty volunteers (10 males and 10 females) with a mean age of 25 years and 9 months (±3 years and 2 months) were each subjected to 4 spectrophotometric measurements of their upper right central incisor. Each sample was measured with alternatively black, 50% grey, white or no background (positive control).
View Article and Find Full Text PDFObjectives: This study evaluated the gloss behaviour of experimental resin composites loaded with different filler percentages, immediately after polishing and after toothbrushing simulation.
Methods: Sixteen disc-shaped specimens were fabricated for each different-charged composite (40%, 50%, 60%, 70% and 75%) and polished with SiC abrasive papers. Gloss measurements were made prior to simulated toothbrushing.
Objectives: The purpose of this study was to determine, by using a spectrophotometer device, the color stability of silorane in comparison with four methacrylate-based composites after being immersed in different staining solutions such as coffee, black tea, red wine, orange juice, and coke, and distilled water as control group.
Methods: Four restorative methacrylate-based composites (Filtek Z250, TetricEvoCeram, Venus Diamond, and Grandio) and one silorane (FiltekSilorane) of shade A2 were selected to measure their color stability (180 disk samples) after 4 weeks of immersion in six staining solutions: black tea, coffee, red wine, orange juice, coke, and distilled water. The specimen's color was measured each week by means of a spectrophotometer (CIE L*a*b* system).
Purpose: This study evaluated the marginal adaptation of supragingivally relocated cervical margins. Newly developed and reference materials were compared.
Materials And Methods: Eighty-eight extracted human teeth were divided into 11 groups.
Purpose: To determine the changes in surface gloss of different composite materials after laboratory toothbrushing simulation.
Methods: 36 specimens were fabricated for each material and polished with 120-, 220-, 500-, 1200-, 2400- and 4000-grit SiC abrasive paper, respectively. Gloss measurements were made with a glossmeter (Novocurve) prior to testing procedures and then subjected to simulated toothbrushing for 5, 15, 30 and 60 minutes by means of an electric toothbrush with a pressure of 2N while being immersed in a 50 RDA toothpaste slurry.
Purpose: To test the marginal adaptation of Class IV restorations made of different composite materials designed for anterior use.
Materials And Methods: Forty-two extracted caries-free human maxillary central incisors were randomly divided into 7 experimental groups - one per composite tested - for which Class IV cavities were prepared. The microfilled composite materials tested (SolidBond/Durafill [D/SB], Syntac classic/Heliomolar [H/SC], Scotchbond1/ Experiment127 [EXI/SB1], Optibond FL/Point 4 [P4/OBFL], Prime&Bond NT/Esthet-X [EX/PBNT], ART Bond/ Miris [MIR/ART], SE Bond/Clearfil ST [CLE/SE-B]) were inserted in two increments after polymerization of their respective adhesive systems.
Objective: To evaluate the optical integration and fluorescence of three contemporary restorative materials used for incisoproximal restorations.
Method And Materials: A microfilled hybrid composite (Amaris, VOCO; MHC), a nanofilled hybrid composite (Grandio, VOCO; NHC), and an experimental ormocer (VOCO; ORM) were used to consecutively restore 10 extracted incisors with incisoproximal restorations using the natural layering concept, mimicking the natural anatomy of the tooth. Before and after placement of each restoration, the teeth were photographed under standardized conditions (direct, indirect, and fluorescent light), and spectrophotometric measurements (SpectroShade, Handy Dental Type 713000, MHT) were made using a black-and-white background.