Biomedical subjects

Filiz Keyf

Publications and source records attributed to Filiz Keyf.

7 recordsLinked to original sources

PubMed2006

A method for positioning the premaxilla during impression making for a patient with bilateral cleft lip and palate: a clinical report.

In patients with bilateral cleft lip and palate (BCLP), orthodontic and facial orthopedic treatments alone occasionally fail to resolve problems because of the absence of alveolar and palatal hard and soft tissue or contraction resulting from previous surgical repair. Prosthetic reconstruction of the anterior maxilla is important for these patients. Patients with BCLP have premaxillary displacement in up to 3 dimensions. It may be difficult to make impressions without deformation. This clinical report describes a method for positioning the mobile premaxilla during impression making for a patient with BCLP.

Adult↗

PubMed2005

The weight change of various light-cured restorative materials stored in water.

This study investigated weight changes of seven different light-cured composite restorative materials, one polyacid glass ionomer compomer, and one light-cured glass-ionomer cement following short-term and long-term storage in water. Two packable composites, three universal (hybrid) composites, one microglass composite, one polyacid glass ionomer resin composite (compomer), one microhybrid low-viscosity (flowable) composite, and one light cured glass ionomer composite cement were evaluated in this study. The weight changes of these specimens were measured daily (short-term storage), and they were measured after six weeks (long-term storage) using an electronic analytical balance. A significant difference was found in Ionoliner, Dyract AP, Opticor flow, Charisma, and Solitare 2, but no significant difference was found in the others (Filtek Z 250, Filtek P60, TPH Spectrum, and Valux Plus). Weight change showed a tendency to increase with the time of water storage. The greatest weight change occurred in light-cured glass ionomer composite cement (Ionoliner), which is followed in order by the weight changes in Dyract AP, Opticor Flow, Charisma, Solitare 2, Filtek Z250, Filtek P60, TPH Spectrum; Valux Plus had the least amount of change.

Absorption↗

PubMed2004

Evaluation of gloss changes of two denture acrylic resin materials in four different beverages.

OBJECTIVES: The primary disadvantages of the materials which are used in construction of complete and removable partial dentures is that their esthetic, physical and mechanical properties change rapidly with time in the oral environment. For esthetics, color stability is one of the criteria that needs careful attention. Color may provide important information on the serviceability of these materials. Color change affects the gloss of these materials. The objective of the present study was to determine the gloss changes resulting from the testing process in four different beverages in one heat-polymerized denture base resin and one cold-polymerized denture base repair resin. METHODS: Thirty-six samples were fabricated for each material. Each sample had a smooth polished and a rough unpolished surface. The gloss measurements were made with a glossmeter before testing. Four different beverages (tea, coffee, cola and cherry juice) were used for testing. Two angles of illumination (20 and 60 degrees) were used for the gloss measurements. The samples were immersed in water, tea, coffee, cola and cherry juice solutions. The gloss of the samples was measured again with the glossmeter at the end of the 45th day and 135th day of testing. The arithmetic mean and standard deviation of each of the samples were calculated and compared with each other statistically by using the Wilcoxon test (within times) (p < or = 0.05 significant), the Kruskal-Wallis analysis of variance (p < or = 0.05 significant) and the Mann-Whitney U-test with Bonforoni correction (when the difference between the samples was significant) (p < or = 0.05 significant). RESULTS: The results of this study revealed that gloss changes occurred after testing in heat-polymerized denture base resin and cold-polymerized denture base repair resin. The significance of the gloss changes exhibited by each sample, kept for different lengths of time in the same solution, were compared using the Wilcoxon test. The results were statistically significant (p < or = 0.05). According to the Kruskal-Wallis analysis of variance, the difference between measurements for angles of illumination was statistically significant (p < or = 0.05). Also according to the Mann-Whitney U-test, the difference between two polished surfaces or two unpolished surfaces was statistically insignificant (p > 0.05), but the difference between smooth polished and rough unpolished surfaces was statistically significant (p < or = 0.05). SIGNIFICANCE: It was found that either the gloss of heat-polymerized denture base resin or the gloss of cold-polymerized denture base repair resin was affected by tested agents, and the four beverages demonstrated noticeable gloss changes. Cherry juice demonstrated the least change, while tea exhibited the greatest change.

Acrylic Resins↗

PubMed2003

The effect of fiber reinforcement type and water storage on strength properties of a provisional fixed partial denture resin.

Fracture resistance of provisional restorations is an important clinical concern. This property is directly related to transverse strength. Strengthening of provisional fixed partial dentures may result from reinforcement with various fiber types. This study evaluated the effect of fiber type and water storage on the transverse strength of a commercially available provisional resin under two different conditions. The denture resin was reinforced with either glass or aramid fiber or no reinforcement was used. Uniform samples were made from a commercially available autopolymerizing provisional fixed partial denture resin. Sixteen bar-shaped specimens (60 x 10 x 4 mm) were reinforced with pre-treated epoxy resin-coated glass fibers, with aramid fibers, or with no fibers. Eight specimens of each group, with and without fibers, were tested after 24 h of fabrication (immediate group), and after 30-day water storage. A three-point loading test was used to measure the transverse strength, the maximal deflection, and the modulus of elasticity. The Kruskal-Wallis Analysis of Variance was used to examine differences among the three groups, and then the Mann-Whitney U Test and Wilcoxon Signed Ranks Test were applied to determine pair-wise differences. The transverse strength and the maximal deflection values in the immediate group and in the 30-day water storage group were not statistically significant. In the group tested immediately, the elasticity modulus was found to be significant (P = 0.042). In the 30-day water storage group, all the values were statistically insignificant. The highest transverse strength was displayed by the glass-reinforced resin (66.25MPa) in the immediate group. The transverse strength value was 62.04MPa for the unreinforced samples in the immediate group. All the specimens exhibited lower transverse strength with an increase in water immersion time. The transverse strength value was 61.13 MPa for the glass-reinforced resin and was 61.24 MPa for the unreinforced resin. The aramid-reinforced resin decreased from 62.29 to 58.77 MPa. The addition of fiber reinforcement enhanced the physical properties (the transverse strength, the maximal deflection, the modulus of elasticity) of the processed material over that seen with no addition of fiber. Water storage did not statistically affect the transverse strength of the provisional denture resin compared to that of the unreinforced resin. The transverse strength was lowered at water storage but it was not statistically significant. The transverse strength was enhanced by fiber addition compared to the unreinforced resin. The glass fiber was superior to the other fiber. Also the modulus of elasticity was enhanced by fiber addition compared to the unreinforced resin.

Acrylic Resins↗

PubMed2003

Comparison of effects of bleach and cleansing tablet on reflectance and surface changes of a dental alloy used for removable partial dentures.

Proper hygienic care of removable partial dentures is important for maintaining a healthy oral mucosa. A daily home care routine is the responsibility of the patient to maintain oral hygiene. A dentist must inform the patient about denture cleansers used for plaque control. Common denture cleansers may negatively affect the surface of alloys used to make partial dentures. The purpose of this study was to evaluate whether bleach and cleansing tablet have deleterious effects on the surface of a dental alloy used to fabricate removable partial dentures. Nineteen test specimens were prepared from CoCr dental alloy. The specimens were cast into 10 mm long x 10 mm wide x 1 mm thick. Fresh solutions made from a commercial bleach and a commercial cleansing tablet were used for each treating. Three groups (commercial denture cleansing tablet, bleach and tap water) were tested. Six specimens were immersed in 200 mL of tap water containing a single denture cleansing tablet. Two spoons of the commercial bleach was added to 200 mL of tap water. Seven specimens were treated. The control specimens were immersed in 200 mL of tap water. Six specimens were the control group. Each specimen was immersed for 30 min per day in the solution for a period of 30 days. The specimens were analyzed for reflectance with a spectrophotometer, for surface changes with a light microscope and weight which was measured with sensitive balance before and after treatment. The SPSS program was used for the statistical analysis. The Kruskal-Wallis Test and Wilcoxon Signed Ranks Test was used. No significant changes of reflectance was shown in the Kruskal-Wallis Test (p > 0.05). The Wilcoxon Signed Ranks Test was performed for comparison into groups. The difference between before and after treatment was statistically significant for the commercial denture cleansing tablet and the commercial bleach (p = 0.028) (p < 0.05). Reflectance was decreased after treatment. Within the limitations of this study, the commercial cleaning solutions had influenced the decrease of reflectance on the surface of the dental alloy. This solutions should not be limitlessly used on dentures with metal components, because they caused clinically significant reflectance changes on the surface of the alloy after 30 days.

Dental Alloys↗

PubMed2003

Alternative impression technique for a speech-aid prosthesis.

OBJECTIVE: Prosthetic treatment for speech disorders attributable to surgically acquired soft palate defects are introduced. CASE: A patient who underwent soft palate resection for cancer is presented. The resected portion of the soft palate was confined to the posterior segments. A prosthesis with a speech bulb was adapted to the patient. CONCLUSION: Excellent restoration of speech and improvement of velopharyngeal function was achieved following placement of the special prosthesis.

Adult↗

PubMed2002

Change in a maxillo-facial prosthesis material effecting from environmental factors: a clinical report.

The purpose of this study was to indicate change in an auricular prosthesis resulting from environmental factors. An auricular prosthesis was made from a commercially maxillo-facial dental materials. The patient used this prosthesis. After one year, the auricular prosthesis was changed, it was nonesthetic. The prosthesis was made over again from the beginning. The prosthesis was changed from environmental factors such as sunlight, wetting and drying, cleaning and secretions. Facial prosthesis was fabricated anew because of color changes and surface changes.

Ear↗