Journal of Marmara University Dental Faculty最新文献

This study compared the tensile bond strengths of soft lining materials polymerized by using conventional water bath methods and microwave energy. The soft lining materials used in this investigation were heat temperature vulcanizing (H.T.V.) silicon material Molloplast-B, and room temperature vulcanizing (R.T.V) acrylic material Getz Soft Oryl. The H.T.V. specimens were prepared with retention, additional retention and without retention, and the R.T.V. specimens were prepared by using bonding agent and bonding agent plus retention. All were cured by both conventional water bath and microwave energy. Results showed that the mean bond strength of H.T.V. specimens ranged from 9.6 to 13.12 kg/cm2, while the mean bond strength of R.T.V. specimens ranged from 0.36 to 1.75 kg/cm2. In both conventional and microwave groups, the specimens prepared with retention, additional retention and without retention or using bonding agent and bonding agent plus retention did not show any significant difference when they were compared separately. But the difference between conventional and microwave groups was found significant in both H.T.V. and R.T.V. specimens. It showed that conventional water bath technique is better than microwave technique.

In this article the fit of all-ceramic crowns, cemented with different luting agents (zinc phosphate and resin cements), was investigated using a scanning electron microscope. The marginal opening of all-ceramic crowns cemented with zinc phosphate cement was 111.9 +/- 40.6 microns which was significantly greater than the 46.7 +/- 12.9 microns marginal opening of Cerestore crowns cemented with resin cement. Total film thicknesses of the cements were not uniform and there were certain discrepancies from margins to walls and to tip due to the die spacer.

There have been many studies on the gutta percha cones used in endodontic therapy. Variations exist between different brands of cone. Since an appropriate cone plays a very important role in the prognosis of therapy, this study examined the surface topography and chemical composition of eight different brands of cone by, a scanning electron microscopy (SEM) and atomic absorption spectrometry. There were some differences between all brands of gutta percha cones.

In this study, 60 complete denture wearers, 53 removable partial denture wearers and 50 dentate subjects were examined to determine the Candidal carrier state. The influence of local factors such as denture type, smoking habits and sex on Candidal carrier rate were investigated. Wearing complete or removable partial denture was determined as an important factor increasing Candidal carrier rate. Cigarette smoking is another factor which increases Candidal growth in complete denture and removable partial denture wearers. In contrast to denture wearers Candidal carrier rate was considerably less on dentate smokers. Candidal colonization rate was found to be higher on the dorsum of the tongue. This suggests that the tongue is the primary oral reservoir of Candida albicans in the mouth.

The purpose of this investigation was to assess the therapeutic effects of the Herbst appliance cephalometrically. Twenty patients were chosen from our clinical intake. Care was taken to select patients who had Class II Div I malocclusion and horizontal growth pattern. Skeletal age was the main selection criterion. Patients in the peak growth period were chosen. A Herbst appliance was used on the first ten patients. The other ten patients served as controls. Standardized profile roentgenograms were taken initially and at the end of a six month observation period. The following results were obtained: 1. Normal occlusal conditions occurred. 2. The mandible was positioned anteriorly and lengthened due to the Herbst therapy. 3. The most significant effect on the maxilla was the decrease in the 1- SN angle and in overjet reduction.

Hypersensitivity reactions to chromium, nickel and cobalt were investigated in the preclinical, fourth year and fifth year students of the Dentistry Faculty of Marmara University, Türkiye. A Standard patch test was performed. Four patches were applied to the shoulder blades of the students. Three of them contained small amounts of 0.5% potassium chromate, 5% nickel sulphate and 1% cobalt chloride respectively. The fourth (control) patch was of petroleum jelly. Questionnaires were used to determine sex and history of any previous allergy to jewelry. After 48 hours, the patches were removed and results assessed. For each base metal, no statistically significant difference was found in the incidence of hypersensitivity reaction between the groups. Nor was there a significant difference in response found between metals, for all of the students tested. Although women were found to have a higher rate of nickel hypersensitivity than men, no such sex difference was found chromium and cobalt. No significant relationship was found between a history of allergy to jewelry and chromium hypersensitivity, however there was a significant difference for nickel and cobalt hypersensitivity. In confirmation of our tests, significant relationships were found between previous allergy histories and the respective patch test results.

Dentin Adhesit, Cavi-Line and Kavite Lak cavity varnishes were applied to the walls of prepared Class V cavities in fifty-two caries free extracted molar teeth before placing amalgam fillings. Tests with Methylene Blue dye after thermocycling showed that all cavity varnishes showed significantly lesser marginal leakage when compared with the control group without any cavity varnish.

The use of antibody levels may identify subjects developing destructive periodontitis or provide markers of disease type. Clinical parameters can be used to group cases but they are incapable of detecting differences in host-susceptibility and host immune response. The validity of radial immunodiffusion (RID) as a laboratory screening method in diagnosis based on antibody quantitation has been evaluated in 36 patients before and after periodontal therapy. It was concluded that the serum IgA, IgG, IgM and parotid IgA concentration profiles, measured with RID have little value in determining the subgroups of early onset periodontitis patients but they can be used to differentiate these groups from slowly progressing adult periodontitis patients.

Levels of Streptococcus mutans in plaque samples from margins of conventional and high copper amalgam restorations were compared in fourteen patients, each having one conventional amalgam filling in each quadrant and one high copper amalgam filling on the contra-lateral side were examined. The percentage of S. mutans of total CFU count in plaque was higher on conventional amalgam than on high copper amalgam. The difference was statistically significant (p < 0.01).

The aim of this study was to evaluate the effect of sealant application in reducing microleakage of the composite resin restorations under in vivo conditions. Occlusal composite resin restorations were made in 24 caries-free primary molars which were about to exfoliate, in children aged between 10 and 13 years. Of these restorations, 12 were sealed with a fissure sealant whereas the others were kept unsealed as controls. After 1 month, the teeth were extracted and immersed in a 2% methylene blue dye solution. The dye penetration alongside the restorations was evaluated using a stereo-microscope. The findings indicated that sealant application significantly (p < 0.05) reduced the microleakage of composite restorations but did not eliminate it completely.