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Objective: To test the shear bond strength, surface characteristics, and fracture mode of brackets that are bonded to enamel etched with an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser operated at different power outputs: 0.5 W, 1 W, and 2 W. Materials and Methods: Human premolars that had been extracted for orthodontic purposes were used. Enamel was etched with an Er,Cr:YSGG laser system operated at one of three power outputs or with orthophosphoric acid. Results: The shear bond strength associated with the 0.5-W laser irradiation was significantly less than the strengths obtained with the other irradiations. Both the 1-W and 2-W laser irradiations were capable of etching enamel in the same manner. This finding was confirmed by scanning electron microscopy examination. The evaluation of adhesive-remnant-index scores demonstrated no statistically significant difference in bond failure site among the groups, except for the 0.5-W laser-etched group. Generally, more adhesive was left on the enamel surface with laser irradiation than with acid etching. Conclusion:The mean shear bond strength and enamel surface etching obtained with an Er,Cr: YSGG laser (operated at 1 W or 2 W for 15 seconds) is comparable to that obtained with acid etching.

By this investigation, two treatment methods, which are currently used in clinical practice, will be evaluated, and the results will be useful for clinicians.

Estrogen deficiency increased orthodontic tooth movements but counts of osteoblasts, which are responsible for new bone formation, were lower in regions of tension and of pressure.

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The aim of this study was to assess quantitative and qualitative alterations in the carrier rate of Candida spp. in south-eastern Turkey among adolescents, and to investigate the effect of fixed orthodontic appliances on the Candida count in a 1-year follow-up study. In the first phase of the study, the oral Candida carriage rate of 72 patients was evaluated. Samples were collected from the dorsal surface of the tongue, the mid-palate and saliva. In the second phase of the study, 42 patients who were determined to be carriers of oral Candida were treated with fixed orthodontic appliances, and from these patients a second set of samples were collected from the saliva and the orthodontic brace surfaces of eight teeth adjacent to the enamel surfaces. The saliva samples were collected before and during orthodontic treatment at 1st, 6th and 12th month, and samples from the braces were collected during the 1st, 6th and 12th month of treatment. Forty-two of the 72 patients (58.5%) were oral Candida carriers. The distribution of Candida spp. in these patients was as follows: (i) Candida albicans was identified in 31 patients (73.8%), (ii) C. tropicalis, C. krusei and C. kefyr were found in three patients each (7.14%) and (iii) C. parapsilosis occurred in two patients (4.76%). During orthodontic treatment, the micro-organism count increased both in the saliva and on tooth surfaces. The results indicate that the prevalence of oral Candida spp. is high in young adults in south-eastern Turkey and that the Candida counts increase when braces are involved.

Aim: To evaluate the levels of interleukin1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) in the samples of gingival crevicular fluid (GCF) taken from the late adult rats during the orthodontic tooth movement and to evaluate the responses to orthodontic treatment . Methodology: In experiment 19 adult (120 days) Spraque-Dawley rats were used. Approximately 15 g force applying open coil spring was applied actively between the upper incisors of the rats. Before and after the activation on the 3rd and 7th and 10th days GCF samples were taken from the vestibular surfaces of appliance fixed teeth using periopaper®. Then the samples were biochemically analyzed. For the statistical analysis of working days of each cytokines repetitive variance analysis technique was used. Results: The levels of IL-1β, IL-6 and TNF-α were the highest in the 3rd day and started to decrease on the 7th and 10th days. Conclusions: The cytokine levels of orthodontic force applied teeth in late adult rats are compatible with the levels of studies in young rats.

Orthodontic appliances often provide good retention sites for oral microorganisms. This leads to a high cariogenic challenge in saliva. The purpose of this study was to evaluate saliva Streptococcus Mutans and Lactobacilli levels in different 5 phase on 24 patients need to both removable and fixed orthodontic application. So we had a possibility to determinate of the S. Mutans and Lactobacilli level in the same sample. These counts were evaluated at 5 stages: before orthodontic treatment, 4 weeks after using of removable appliances, at least 2 weeks after bonding of the brackets, 1 week after application of mouth varnish, and at the end of the orthodontic treatment.Wilcoxon signed ranks test were used to statistical determination. This study shows that orthodontic removable appliances treatment doesn't affect the lactobacilli levels significantly (P>0.05) whereas the level of the S.mutans increased significantly (P<0.05). Besides of that the level of the lactobacilli and S. Mutans didn't change significantly during fixed orthodontic treatment in this oral hygen condition as we advised (P>0.05). In addition, we found that when patients use mouth varnish during fixed orthodontic treatment these microorganism levels reduced significantly (P<0.05).