Effects of fluoride versus amorphous calcium phosphate solutions on enamel microhardness of white spot lesions : an in-vitro study

Development of white spot lesions around orthodontic fixed orthodontic appliances is a common finding, especially in patients with poor oral hygiene. One of the conservative interventions for regression of these lesions is using chemical solutions. The current study aimed to compare the effectiveness of fluoride and amorphous calcium phosphate (ACP) on microhardness improvement of affected enamel. Forty-five intact human incisor teeth were selected and randomly divided into 3 groups of 15. Fluoride group, ACP group and artificial saliva group (control group). Inducing of white spot lesion was done by PH-cycling model. Samples of the first and second group were submerged into 0.05% fluoride and 0.05% ACP solutions respectively for one minute a day. The rest of the time, all specimens were put in artificial saliva, which was incubated in 37 °c temperature. Microhardness of specimens was assessed by Vickers microhardness test in three stages: 1: Baseline microhardness assessment that was done before induction of white spot lesion, 2: Secondary microhardness assessment that was done after induction, 3: Final microhardness assessment that was done after chemical treatment. The SPSS 11.5 software was used for statistical analysis and p< 0.05 was considered as significant. Microhardness of specimens in the fluoride and ACP groups had significantly improved after the treatment (between secondary assessment and final assessment). In the control group, no significant improvements were observed. In final assessment, there were significant differences between the ACP and control groups, but no significant differences were found neither between the fluoride and ACP, nor the Fluoride and control groups. According to the current study, both 0.05% ACP and 0.05% fluoride solutions enhanced enamel micro-hardness in treatment of white spot lesion

Assessment of renal transplant dysfunction by doppler sonography: A systematic review and meta-analysis

Background: Doppler sonography parameters, particularly the resistive index (RI), have been identified as an essential tool for assessing renal transplant dysfunction (RTD). However, there is some ambiguity in the findings of previous research studies on this matter. Therefore, the objective of our study is to examine the relationship between changes in RI subsequent to RTD. Methods: This was a systematic review and meta-analysis study. We searched three electronic databases PubMed, Web of Science, and Scopus, from the year 2000 to 10 May 2022. The main effect size was considered as the mean RI differences of cases with RTD confirmed by biopsy with control patients with no RTD. We used random effect models to pool the effect size. Results: Thirteen studies were included in our review. The pooled mean (95% CI) for the control group was calculated to be 0.71 (0,67, 0.75) and for patients with renal transplant dysfunction was 0.73 (0.68, 0.78), under a random effect model with high heterogeneity for both analyses (I2=98% and 97%, respectively). The pooled mean was significantly different between the control group and patients with RTD (P= 0.05), based on a t-test of pooled effect sizes. Conclusions: Based on the result of our study, we showed that there is a significant difference between RI in patients with kidney transplant dysfunction and the control group. However, RI cannot substitute kidney biopsy in the management and diagnosis of RTD

Orthodontic Wire Ingestion during Treatment: Reporting a Case and Review the Management of Foreign Body Ingestion or Aspiration (Emergencies)

Today orthodontic treatment is in growing demand and is not limited to a specific age or social group. The nature of orthodontic treatment is such that the orthodontic wires and appliances, which are used to apply force and move the teeth, are exposed to the oral cavity. Shaping and replacing these wires in oral cavity are the major assignments of orthodontist on appointments. Therefore, we can say that orthodontic treatment requires working with dangerous tools in a sensitive place like oral cavity which is the entrance of respiratory and digestive systems. In this paper, a case of ingesting a broken orthodontic wire during eating is reported, and also necessary remedial measures at the time of encountering foreign body ingestion or aspiration are provided

Effect of Four Methods of Surface Treatment on Shear Bond Strength of Orthodontic Brackets to Zirconium

Objectives: Providing reliable attachment between bracket base and zirconia surface is a prerequisite for exertion of orthodontic force. The purpose of the present study was to eval- uate the effect of four zirconium surface treatment methods on shear bond strength (SBS) of orthodontic brackets. Materials and Methods: One block of zirconium was trimmed into four zirconium sur- faces, which served as our four study groups and each had 18 metal brackets bonded to them. Once the glazed layer was removed, the first group was etched with 9.6% hydrofluoric acid (HF), and the other three groups were prepared by means of sandblasting and 1 W, and 2 W Er: YAG laser, respectively. After application of silane, central incisor brackets were bonded to the zirconium surfaces. The SBS values were measured by a Dartec testing ma- chine with a crosshead speed of 1 mm/min. Results: The highest SBS was achieved in the sandblasted group (7.81±1.02 MPa) followed in a descending order by 2 W laser group (6.95±0.87 MPa), 1 W laser group (6.87±0.92MPa) and HF acid etched group (5.84±0.78 MPa). The differences between the study groups, were statistically significant except between the laser groups (P < 0.05). Conclusion: In terms of higher bond strength and safety, sandblasting and Er: YAG laser irradiation with power output of 1 W and 2 W can be considered more appropriate alterna- tives to HF acid etching for zirconium surface treatment prior to bracket bonding