Objective To reevaluate proven strengths and weakness of glass ionomer cements (GICs) and to identify agreement versus conflicting evidence in previous reports regarding the transition between GIC and the tooth, and the existence of an "interphase". Materials and methods Relevant electronic databases (PubMed, Embase via Ovid and Medline via Web of science) were searched for publications of evidence relating to the transition zone at the GIC-tooth interphase. Studies were examined and grouped according to characteristics of GIC-tooth attachment area quantified by X-ray and optical microscopy techniques in 2D and 3D. Results Inclusion criteria comprised of in vitro studies that showed images of the conventional GIC-tooth substrate attachments using at least one of the following techniques: SEM, CLSM, or μCT. The search identified 419 studies, from which 33 were included. Ten studies demonstrated the existence of an interphase layer and five studies quantified the layer thickness (1-15 μ). Twenty-nine publications studied different failure modes of the GIC-tooth interphase. Eleven studies described discontinuities inside the GIC bulk. Conclusion The GIC-tooth interphase attributes evolve with time. Good attachment is evident even under compromised surface preparation. The GIC-tooth attachment area is resistant to acidic dissolution as compared to both tooth and GIC bulk. In general, studies revealed mostly intact GIC-tooth interphases with only some cracked interphases. Clinical significance GIC bonds to the tooth structure and forms an acid resistant attachment zone that might enhance caries inhibition. Due to fluoride release and ease of use, GIC provides a cost effective treatment, ideal for low income or high caries populations.

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Objectives: The determine the frequency of how common white spot lesions in orthodontic patients .Materials and Methods: A total of 147 patients who visited the Orthodontics department at Khyber College of Dentistry, Peshawar were included in the study. Intraoral pictures were acquired using a DSLR camera before and after therapy (6 months after fi xed device insertion) (D600). The development of white spot lesions was evaluated between pre and post-therapy photos. SPSS version 20.0 was used to analyze the data.Results: Eight four were female (57.1%) and sixty-three were males (42.9%). The mean age was 21.45±4.87 years. The overall frequency of WSL in pre-treatment patients was in four patients (2.7%) only. Out of total 147 patients, 68 (46.3%) patients had WSL while 79(53.7%) were WSL free at mid-treatment time. The frequency of WSL in pre-treatment and mid-treatment was statistically signifi cant having p-value of 0.04. The frequency of WSL stratifi ed by gender showed that females had more WSL than males. The frequency of WSL stratifi ed by age showed that maximum number of cases those had WSL were from 13 to 15 years of age, followed by 26 to 30 years. The stratification for frequency of WSL by age was not statistically signifi cant having p-value of 0.602. Conclusion: During the fi rst six months of treatment, the number of WSLs increased dramatically in this clinical investigation. During the fi rst few months of treatment, clinicians should assess patients' dental hygiene and must take further precautions to prevent the occurrence of WSL.

Bones are nanocomposites of protein, mineral and water that form mineralized collagen fibrils arranged in a variety of layered lamellae. Bone material has a long evolutionary record and specific bones attain shapes and microstructures that have well stood the test of time such that they can be considered optimized to match their function. Further, most bones typically contain entombed living cells, osteocytes responsible for adaptation, healing and biochemical signaling. The bones of pike fish (Esox lucius) are different because, as with other advanced teleost species, they evolved to eliminate osteocytes from the microstructure. This suggests that these cells are not needed because these bones are more damage resistant than mammalian bones. Here we explore details of this biologically-grown structure, using a combination of light and X-ray based characterization methods. We report the three-dimensional arrangement and composition of the heavily cyclically-loaded pivot of the cleithrum bone in the pectoral girdle of pike. By combining absorption and phase contrast-enhanced micro-computed tomography, electron microscopy, polarized light microscopy and second harmonic generation multi-photon confocal laser scanning microscopy we reveal the principle layout of the bone of this predator which we determine at the millimeter, micrometer and nanometer lengthscales.