Examining the effect of exposure time on the erosive potential of sour candy

This study aimed to evaluate the erosive potential of sour candy at a different time of exposure within a laboratory-based setting. Fifty human anterior tooth samples were randomly assigned into three groups, namely: sour candy, regular candy A, and deionized water (n=15). Each tooth sample was exposed to a solution containing the sample groups at different time intervals. Vickers hardness tester was used to measure the surface hardness pre- and postexposure. The mean surface hardness value measured was compared using a paired sample test (α =.05). Raman spectroscopy was used to study the change in the enamel structure in all sample groups. A significant difference in the surface hardness value was measured pre and post-exposure in all the sample groups (P<0.01). The samples exposed to sour candy had the highest tooth surface loss. In terms of the time of exposure, it was found that prolonged exposure had a significant effect on the surface hardness (P<0.01). The Raman intensity change confirmed that samples exposed to sour candy, after 2 hrs of exposure, had the highest loss of structural integrity. The study conclude that sour candies are very erosive and its impact enhances with time.

Dissolution of Enamel on Exposure to Various Commercial Beverages Available in India

ABSTRACT Aim The study was aimed to estimate the pH of the commonly available soft drinks in the Indian market and to assess the detrimental effects of the juices and beverages on the tooth surface by measuring the weight loss of the tooth sample. Materials and methods The study was done with eight different types of commercially available carbonated drink and fruit juices available in the Indian market among which six were carbonated drinks and two were juices. Carbonated drinks experimented were Coca-Cola, Pepsi, Fanta, Mirinda, 7Up and Sprite, and two fruit juices were Tropicana orange juice and real orange juice. Ten different bottles from each category were obtained, and the pH was estimated. Each of the beverages was divided into batch of 10 containers containing the tooth sample. Weight of all samples was measured at 24, 48, 72, 96, and 120 hours with subsequently changing each solution at an interval of 24 hours. Results The mean pH of the beverages was found ranging from 2.13 ± 0.02 in Pepsi to 3.41 ± 0.02 in Tropicana on opening. The mean pH of water was found to be 6.98 ± 0.01. Among carbonated drinks, the mean weight loss after 24 hours was highest in Coca-Cola and least in 7Up. Tropicana fruit juice had a higher tooth loss than real orange juices. When compared with water, the tooth loss was significantly higher in Coca-Cola after all specified time (hours). Conclusion The pH of both carbonated drinks and fruit juices was below the critical pH. The weight loss was also seen after every 24 hours in all the carbonated drinks and beverages. The study showed that these commercial beverages are harmful to the tooth structures, and hence, the health professionals a major role in educating the population about its effects and advising them to use these products precisely. Clinical significance The change in lifestyle has increased the demand of soft drinks and artificial juice in Indian market. The use of these carbonated drinks and fruit juices causes damage to the tooth structure in all ages, especially in young mass. Our study provides an idea about the deleterious effects of these commercial drinks on dental hard tissues. How to cite this article Panda A, Ghosh B, Pal I, Kumar V, Bhuyan L, Dash KC. Dissolution of Enamel on Exposure to Various Commercial Beverages Available in India. J Contemp Dent Pract 2017;18(11):1009-1013.

Ablation of Selected Dental Materials Using Er,Cr:YSGG Laser

The effect of Er,Cr:YSGG laser for ablation of commercialized adhesive dental materials were studied using 12 sets of tooth samples. The surface morphology and composition of the tooth samples was observed before and after irradiation using FESEM and EDX. Time dependency of exposure is observed in the tooth sample. Adhesive material Grēngloo produced better ablation on long exposure compared to adhesive material Blūgloo. The ablation effect was also compared between presence and absence of water. The enamel surface produced is highly dependent on the technique used to ablate the adhesive material. Without water, enamel surface appeared roughed and depth of crater was also created. In particular, both materials produce different quality of ablation and reacted differently under different laser parameter and setting.

Composite Flowable Fabricated (CFF) Sebagai Alternatif Bahan Pasak Gigi Paska Endodontik

Penelitian ini bertujuan untuk menggali, menganalisis dan membandingkan pasak CCF (plastis) dengan pasak NiTi logam (rigid) sebagai alternatif pasak gigi paska perawatan endodontik yang biokompatibel. Penelitian ini menggunakan sampel elemen gigi insisif rahang atas yang telah disesuaikan dengan kriteria penelitian. Semua sampel gigi diberi perlakuan sesuai dengan kelompoknya. Prosedur kelompok pasak CCF yaitu dengan mengaplikasikan komposit flowable pada saluran akar gigi yang telah dilakukan pengambilan gutta-percha sedalam 2/3 panjang saluran akar dan menyisakan 1/3 gutta-percha di daerah apikal, sampai seluruh saluran akar dan ruang pulpa terisi penuh. Komposit flowable dilakukan penyinaran (curing LED) selama 20 detik. Perlakuan pada kelompok pasak NiTi sama seperti pada kelompok pasak CCF, bedanya pasak NiTi diinsersi menggunakan bahan luting semen ionomer kaca tipe 1. Selanjutnya semua sampel gigi baik yang prefabricated maupun fabricated dilakukan uji three bending point dengan pengaturan sesuai dengan standart ISO10477. Secara deskriptif nilai rerata kelompok pasak NiTi (stiffness = 115,30 N/mm; modulus elastisitas = 9,31 Gpa; flexural = 812 Gpa) lebih besar dari nilai rerata kelompok pasak CFF (stiffness = 35 N/mm; modulus elastisitas = 3,45 Gpa; flexural = 475,8 GPa) dan secara statistik hasil penelitian menunjukkan terdapat perbedaan yang signifikan antara pasak prefabricated (NiTi) dengan fabricated (CFF). Sehingga dapat disimpulkan bahwa walaupun secara deskriptif dan statistik ada perbedaan, namun bahan komposit flowable dapat dijadikan sebagai bahan pasak alternatif dan perlu penelitian lebih lanjut yang sesuai standar keberadaannya sebagai bahan pasak alternatif. Composite Flowable Fabricated (CFF) as Enddodontic Dental Post alternative. Composite Flowable Fabrcated (CFF). CFF is composite resin that viscous and plastic which used as material to enhance the retention and stability of post endodontic treatment and restoration materials. NiTi post is prefabricated post endodontic that the insertion needs luting material. This study was to explore, analyze, and compare CCF (plastic) and NiTi (rigid) post endodontic as alternative of post endodontic that is compatible. This study used element sample of maxillary incisive tooth. All of teeth sample was taken treatment that was appropriate with the groups. the procedure of CFF post group was to make application of flowable composite in root canal up to full that had been done taking of gutta percha as deep as 2/3 of root canal length and left 1/3 gutta percha in apical area. Flowable composite was cured by LEDfor 20 seconds. Treatment of NiTi post group was same with CCF post group, the different NiTi post was inserted using glass ionomer luting type 1. Furthermore all of tooth sample, prefabricated and fabricated, was tested by threebending point with ISO10477. The result showed that mean of NiTi post (stiffness= 115,30 N/mm; modulus elastisitas = 9,31 Gpa; flexural= 812 Gpa) was higher than CFF post (stiffness = 35 N/mm; modulus elastisitas = 3,45 Gpa; flexural= 475,8 GPa); and there was significant different between prefabricated (NiTi) dengan fabricated(CFF) post statistically. Although composite flowable can be used as alternative of post endodontic and needs further research that is suitable with standard of post materials.

Pitting process visualization

The paper describes time-domain simulation of gear pitting damage using animation program. Key frames have been used to create illusion of motion. The animation uses experimental results of high-cycle fatigue of material. The fatigue damage occurs in the nominal creep area on the side of the gear tooth sample loaded with variable-positioned Hertz pressure. By applying the force, the pressure cumulates between two convex surfaces. This phenomenon results in material damage under of curved surfaces in contact. Moreover, further damage has been registered on the surface. This is due to exceeding the elastic-plastic state limit and development of „tabs“. The tabs serve as origin of surface micro cracks powered by shear stress and enclosed grease pressure as well. This deformation and extreme pressures of Pascal law contribute to elongation and growth of the surface micro crack. Non-homogenous parts of material volume support the initialization/development of the micro cracks as well. Resulting visualization of the tooth-side fatigue damage provides clear and easy-to-understand description of the damage development process right from the micro crack initialization to the final fragmentation due to pitting degradation.

DEVELOPMENT AND EVALUATION OF RECONSTRUCTION METHODS FOR AN IN-HOUSE DESIGNED CONE-BEAM MICRO-CT IMAGING SYSTEM

Purpose: Cone-beam micro computed tomography CT (micro-CT) can offer comprehensive 3D information and high-resolution images. This technology can be used with other imaging modalities in the preclinical application of molecular imaging research. Image reconstruction algorithm affects final image spatial resolution, which is the primary topic of this study. We use two types of reconstruction methods, which are analytical (tent-FDK) and statistical iterative (convex algorithm) algorithms, to reconstruct the micro-CT images for evaluation. Materials and Methods: In this study, projection data of the Defrise phantom and HA (Hydroxy-Apatite) phantom were obtained using an in-house designed micro-CT imaging system and images were reconstructed with the tent-FDK and convex algorithms. We develop a new way to calculate the system matrix of our micro-CT. Human tooth sample and mouse bone sample data were reconstructed with the analytic and iterative algorithms. Results: The Defrise phantom results show coronal view of the images reconstructed by the tent-FDK and convex algorithms. From the profile of the results, image reconstructed by the convex algorithm has higher pixel value in the high-density layer. Comparison of the results of human tooth sample and mouse bone sample reconstructed by the two kinds of algorithms, the image reconstructed by the convex algorithm has fewer artifacts and more correct pixel value representing for the attenuation coefficients. Conclusion: Tent-FDK algorithm is a kind of useful analytic method to reconstruct cone-beam CT data. We also develop the convex iterative method to reconstruct images for low dose X-ray cone-beam CT, which performs better than the analytical one in general.