Objective: The aim of this study was to compare the effects of three enamel etching modes - laser-etch, self-etch and acid-etch (5, 10 and 15 s) - on bracket bonding, using a universal adhesive. Methods: Eighty-four maxillary premolars were randomly divided into seven groups (n=12) based on the etching method and the adhesive used for bracket bonding. After water storage and thermocycling, shear bond strength was measured, and adhesive remnant index scores on debonded enamel were determined. Results: There were significant differences between the seven groups regarding bond strength values (p< 0.001). The highest values were observed in universal adhesive with laser etching group, while Transbond XT with acid or laser etching, and universal adhesive used in self-etch mode demonstrated the lowest bond strength. The universal adhesive with the three different etching times presented with statistically similar results, all showing an improvement in bond strength, compared with Scotchbond universal (SBU)/SE. Conclusions: The universal adhesive evaluated in the present study demonstrated statistically similar bond strengths to conventional orthodontic adhesive in self-etch mode. The bond strength can be improved by adding an initial acid etching or laser conditioning step, although enamel damage was observed in some cases.

The state-of-the-art approach to regenerating different tissues and organs is tissue engineering which includes the three parts of stem cells (SCs), scaffolds, and growth factors. Cellular behaviors such as propagation, differentiation, and assembling the extracellular matrix (ECM) are influenced by the cell’s microenvironment. Imitating the cell’s natural environment, such as scaffolds, is vital to create appropriate tissue. Craniofacial tissue engineering refers to regenerating tissues found in the brain and the face parts such as bone, muscle, and artery. More biocompatible and biodegradable scaffolds are more commensurate with tissue remodeling and more appropriate for cell culture, signaling, and adhesion. Synthetic materials play significant roles and have become more prevalent in medical applications. They have also been used in different forms for producing a microenvironment as ECM for cells. Synthetic scaffolds may be comprised of polymers, bioceramics, or hybrids of natural/synthetic materials. Synthetic scaffolds have produced ECM-like materials that can properly mimic and regulate the tissue microenvironment’s physical, mechanical, chemical, and biological properties, manage adherence of biomolecules and adjust the material’s degradability. The present review article is focused on synthetic materials used in craniofacial tissue engineering in recent decades.

Background: Medication is one of the supplementary steps in dental treatment. Dentists prescribe medicine in order to avoid postsurgery complications. To the best knowledge of the researchers, no thorough study has been carried out to review the prescribed drugs in Fars province, Iran. Objectives: The current study aimed to determine the current status of the issue and compare it with global standards. Materials and Methods: In this cross sectional study, 1120528 prescriptions prescribed by the dentists of Fars province from 2006 to 2011 were reviewed in terms of the number of items, the types of drugs and the most commonly prescribed drugs. Results: The average number of drugs in every prescription in Fars province, Iran was 2.26 ± 0.56. About 82% of the prescriptions included at least one antibiotic and 21% included at least one corticosteroid. Amoxicillin (23.71%), metronidazole (10.6%) and ibuprofen (7.5%) were the most common prescribed drugs. Conclusions: Compared to the developed countries, dentists of Fars acted properly regarding the average number of drugs found in every prescription. But in prescribing antibiotics, corticosteroids and injections they need further education.

Background:Latex elastics are still in common use due to their low cost and high flexibility to improve sagittal discrepancies or interdigitation of teeth. Mechanical properties of elastics are influenced by several environmental factors such as pH changes. This study evaluated similar latex elastics to define the influence of synergic effect of intermittent low pH and various baselines pH of saliva.Materials and Methods:Four groups of latex elastics (3-M Unitek, 3/16 inch) were tested (n = 15 in each group). Two groups of elastics were immersed in two tanks of artificial saliva with different pH levels of 7 and 5, and two groups were immersed in two tanks of artificial saliva with intermittent drop of pH to 4. The force was measured when the elastics were stretched to 25 mm. These measurements were taken in 0, 4, 8, 12, 24, 36, and 48 h for each group. Repeated measures analysis of variance (RMANOVA) and post-hoc Tukey's test were used to assess the findings. The level of significance was 0.05%.Results:The interaction between pH and time analyzed with RMANOVA showed no significant differences (P > 0.05) except in 36 h (P = 0.014). The Tukey's analysis showed that each comparison between any two groups did not indicate significant differences (P > 0.05) except between Groups 1 and 3 and between Groups 2 and 3 (P < 0.05).Conclusion:No significant correlation was seen between fluctuation of pH and force degradation in latex elastic band except in 36 h.

Background: Retakes of intra oral radiographs happen frequently in dental practice although radiographic courses train dental students in consecutive semesters.To reduce the patient exposure as much as possible it is mandatory to reduce the number of retakes both in radiology clinics and educational centers.Materials and Methods: 3188 periapical radiographs taken by bisect-angle technique was evaluated in this cross-sectional study to assess the frequent errors necessitating retakes. Views were taken by fourth year dental students using bisect angle method. Errors were tabled according to site and type.Results: The four major errors that were found in the study included incorrect film placement (35.4%), cone cutting (18.2%), incorrect horizontal angulation (16.6%), and incorrect vertical angulation (14.4%). The distribution of technical errors by anatomic location was identified. Maxillary molar area was the most occurring site for errors. Conclusion: These results suggest that educational programs may be re-evaluated to make the best benefit of educational courses involving both dental and hygiene students.