Fahinur Ertuğrul

Bond strength of glass-ceramics on the fluorosed enamel surfaces.

OBJECTIVES Effect of different adhesive luting systems on the shear bond strength of IPS Empress 2 ceramic restorations to fluorosed enamel surface was investigated. METHODS Forty-eight ceramic discs (2 mm x 3 mm; IPS Empress 2) were fabricated. Twenty-four non-carious extracted human molar teeth with fluorosis and 24 without fluorosis were cleaned with pumice using a plastic brush and then they were divided into two main groups. The IPS Empress 2 ceramic discs were luted to the teeth of four subgroups with two different adhesive luting systems, Variolink 2/Excite DSC (etch-and-rinse) and Clearfil Esthetic Cement/ED Primer II (self-etch), thermocycling was performed 5000 times. Shear bond strengths were tested using Shimadzu Universal Testing Machine until failure. An optical microscope and image analyzer were used at 10x and 1000x magnification to analyze the surfaces for adhesive, cohesive and mixed failure percentages. Data was analyzed with one-way ANOVA and Tukey test at a significance level of p<0.05. RESULTS Mean shear bond strength data of the groups in MPa were; Variolink 2/Excite DSC on fluorosed enamel: 18.3+/-3.08, Variolink 2/Excite DSC on non-fluorosed enamel: 18.79+/-2.65, Clearfil Esthetic Cement/ED Primer II on fluorosed enamel: 8.43+/-2.45, Clearfil Esthetic Cement/ED Primer II on non-fluorosed enamel: 13.53+/-1.68. Mixed failure was the most prevalent type of failure in moderate fluorosed and non-fluorosed teeth with etch-and-rinse dentin bonding system, and in fluorosed teeth with self-etch dentin bonding system. CONCLUSIONS The use of an etch-and-rinse adhesive luting procedure produced higher bond strengths of glass-ceramics bonded to fluorosed and non-fluorosed enamel surfaces than the self-etch bonding system.

Multidiciplinary treatment of complicated subgingivally fractured permanent central incisors: two case reports

Subgingival crown fractures with pulp exposure in permanent teeth present both endodontic and restorative problems with unfavorable prognosis. Numerous restorative techniques such as resin composite restorations with and without pins, crowns and reattachment of the fractured dental fragment could be listed as the treatment options. There are several successful cases in the literature where advantages of less microleakage and proper gingival biocompatibility in cases with reattachment of the tooth fragment were reported. Two cases of palatinal subgingival crown fractures are reported. Both had been restored by reattachment of the fragment and composite with the help of the flap surgery. Follow up visits (Case 1 for 4 years and Case 2 for 1 year) revealed satisfactory esthetics and function.

Biocompatibility of glass ionomer cements with and without chlorhexidine.

Objective: The aim of the present study is to evaluate the biocompatibility of glass ionomer cements (GICs) with and without chlorhexidine (CHX) as well as coated with varnish or not using in vitro cytotoxicity test. Materials and Methods: Biocompatibility of Fuji IX, Fuji IX with varnish, Fuji IX with 1% CHX diacetate and Fuji IX with 1% CHX diacetate with varnish was determined with in vitro cytotoxicity assay by using L929 mouse connective tissue fibroblasts. After 72 h, cell viabilities were evaluated by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay to determine the effects of the cements on the mitochondrial function and microscopic images were taken by scanning electron microscopy. Results: Statistical analysis was performed by one-way analysis of variance followed by the Bonferroni post-hoc test at a significance level of P < 0.05. 72 h after treatment, there were statistically significant differences between Fuji IX and Fuji IX-CHX (P < 0.001). In addition, the reduction of the cytotoxicity by coating the GICs with varnish was indicative and increased the cell viability ratio (P < 0.001). Conclusions: Fuji IX coated with varnish was found to be the most biocompatible one among others. Thus adding CHX significantly reduced the cell viability, it is assumed that, due to the leakage of CHX and the other components of the GICs to the cell culture medium, the cell viabilities were decreased, so it is highly recommended to use varnish not only to reduce the water loss from the GICs, but also to reduce the cytotoxicity of the GICs.

Antibacterial efficacy of prophylactic ozone treatment on patients with fixed orthodontic appliances.

Abstract Objective. This study investigated the efficacy of ozone on microflora of patients with fixed orthodontic appliances. Materials and methods. Ten subjects undergoing fixed appliance therapy were enrolled in the study. Before any application, two elastic ligatures were removed with the aid of a sterile probe from the premolar brackets on the upper right and lower left jaws for baseline bacteriological counts. Then ozone gas was applied for 180 s by running the device on prophylaxis mode with included mouth tray according to the manufacturers recommendations on all brackets. After the ozone application, two other elastic ligatures were removed from the opposite sides of the mouth of the patients. One week after the application two more elastic samples, which were not changed in the previous session, were collected from the upper right and lower left premolar brackets. The elastic ligatures were immersed in transfer solutions and cultured to determine the Streptococcus mutans and Lactobacillus acidophilus. Statistical analysis of the data was obtained by paired Students t-tests. Results. The ozone treatment reduced the S. mutans and L. acidophilus immediately after the application and these reductions were found to be statistically significant (p = 0.038 and p = 0.020). Both the S. mutans and L. acidophilus values increased by the 1-week period and the S. mutans values were significantly higher than the baseline values (p = 0.01). Conclusion. It can be concluded that the ozone treatment may have an instantaneous lethal effect on S. mutans and L. acidophilus; however, within the limitations of this study, a long-term preventive effect could not be observed.

Comparison of conventional versus colored compomers for class II restorations in primary molars: a 12-month clinical study.

Objective: To evaluate the 12-month clinical performance of conventional (Compoglass F) and colored (Twinky Star) compomer restorative materials in class II restorations of primary molars. Materials and Methods: A total of 196 restorations were placed in 98 children aged between 5 and 10 years (mean age: 7.43 ± 1.31 years) who had bilateral matched pairs of carious posterior class II primary molars. A split-mouth design was used in which 2 materials (Compoglass F, Twinky Star) were randomly placed on contralateral sides by 3 dentists. At baseline, after 6 and after 12 months, the restorations were evaluated using modified US Public Health Service criteria for: secondary caries, marginal integrity, marginal discoloration, anatomic form and surface texture. The Alpha and Bravo scores were considered as clinical success. The data were subjected to statistical analysis by the Wilcoxon and McNemar tests (p < 0.05). The Kaplan-Meier survival method was applied to estimate survival percentages. Results: No significant difference was found among the groups at all recalls regarding marginal integrity, marginal discoloration, anatomic form, secondary caries and surface texture. The 12-month mean cumulative survival rate of Compoglass F was 95.7%, while in the Twinky Star group, the survival rate was 93% in class II restorations with no significant difference between the groups for either material. Conclusion: Both conventional and colored compomer materials are suitable restorative materials for primary teeth for at least 12 months. Colored compomers could also be a good alternative to tooth-colored compomers in the restoration of primary molars.