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Impact of Dental Caries on Survival of Polymeric Restorations
Published in Mary Anne S. Melo, Designing Bioactive Polymeric Materials for Restorative Dentistry, 2020
Maximiliano Sérgio Cenci, Tamires Timm Maske, Françoise Hélène van de Sande
Regarding physical properties, the polymerization shrinkage/stress that may compromise the adhesive bonding between resin composite and tooth interfaces leading to gap formation, remains a concern (Nedeljkovic et al., 2015), and the presence of a gap has been related to secondary caries formation in vitro and in situ studies (Kuper et al., 2015a; Maske et al., 2017). Low-shrinkage resin composites were introduced to minimize polymerization stress, which could reduce adhesive failures between tooth and restoration (Pitel, 2013). Nonetheless, overall failure rates, secondary caries, and marginal adaptation of low-shrinkage resin composites do not suggest that there is any improvement when compared to resin composites containing 2-hydroxyethyl methacrylate (HEMA), triethylene glycol dimethacrylate (TEGDMA), or other low-molecular-weight monomers (Magno et al., 2016; van Dijken and Pallesen, 2017). Besides, there is no clinical evidence showing that the presence of a gap would lead to secondary caries development (Mjor and Toffenetti, 2000; Heintze and Rousson, 2012; Ferracane and Hilton, 2016).
Hollow Microneedles
Published in Boris Stoeber, Raja K Sivamani, Howard I. Maibach, Microneedling in Clinical Practice, 2020
Integration methods of hollow microneedle arrays with secondary systems have to take the microneedle material and the intended application into consideration. In intradermal drug delivery systems, the high liquid pressures involved in intradermal injection (41) settings requires a strong seal between the microneedle arrays and the supporting structures. For silicon, due to its brittleness, the most common integration method for this application is adhesive bonding of the array to a rigid backing such as brass (14) or plastic (13, 42) that provides a support for the majority of the backing plate. In addition, there exist several direct bonding methods for silicon. The irreversible chemical bonding of plasma surface-activated PDMS and silicon has been used to bond a chip with a row of in-plane silicon needles to a PDMS channel system (2) or to generate an integrated MEMS syringe (43); however, the flexibility of PDMS and the large unsupported area above the fluid reservoir make this silicon-needle-based MEMS syringe very fragile. Anodic bonding forms an irreversible bond between silicon and Pyrex™ and has been used to integrate an array of silicon microneedles with a channel system etched into the back side of the needle backing with a Pyrex™ chip for fluid extraction (18).
Influence of the Er,Cr:YSGG laser and radial firing tips on the push-out bond strength of glass fiber posts
Published in J. Belinha, R.M. Natal Jorge, J.C. Reis Campos, Mário A.P. Vaz, João Manuel, R.S. Tavares, Biodental Engineering V, 2019
A.I. Araújo, M. Martins, J.C. Reis Campos, A. Barros, A. Azevedo, T. Oliveira
The results presented in this study indicates that, despite not being statistically significant compared to the manufacturer’s standard protocol, the adjunctive Er,Cr:YSGG laser treatment of the post-space prior cementation increased the bonding strength of glass fiber posts within the entire root length. These results may be attributed to the laser capacity for smear layer removal and modification of dentin morphology, resulting in higher adhesive bonding strength and push-out resistance of glass fiber posts. Further clinical studies may confirm whether this can be considered clinically relevant for the long-term stability of crown restorations.
Bulk Fill flow resin contraction using 3D finite element model and calibration by Fiber Bragg Grating measurement
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Claudio Antunes Junior, Emílio Graciliano Ferreira Mercuri, Ana Paula Gebert de Oliveira Franco, Manoella Costa, Leandro Zen Karam, Hypolito José Kalinowski, Osnara Maria Mongruel Gomes
The aim of the present work is to understand the resin and adhesive stresses generated by polymerization shrinkage together with chewing and bite forces that can inuence the adhesive bonding and failure. The strain and temperature are measured by FBG (Fiber Bragg Grating) sensors inside a resin in a laboratory polymerization test and are used to calibrate the stresses inside the resin three-dimensional model using Finite Element model. After it, bite forces are applied in the tooth model to analyze the stresses generated in the adhesive and compare with the bond strength parameter, checking if there are critical regions. The laboratory experiment was performed in the FiltekTM Bulk Fill Flow resin followed by an mechanical analysis of the stresses in the Single Bond adhesive with a load of non-cyclic bite forces, considering the contraction generated in the polymerization of the resin. Thus it is possible to evaluate whether the loads can generate higher stresses than the tensile and shear bond strength in the adhesive.
Marginal gap and fracture resistance of CAD/CAM ceramill COMP and cerasmart endocrowns for restoring endodontically treated molars bonded with two adhesive protocols: an in vitro study
Published in Biomaterial Investigations in Dentistry, 2020
Israa Atif Kassem, Ibrahim Elsebai Farrag, Samir Mahmoud Zidan, Jylan Fouad ElGuindy, Reham Said Elbasty
Note that the present study did not consider the long-term effects of aging on the marginal gap,[52] the long-term behavior of restorations,[53] or the influence of parafunctional habits.[54] Further research remains required to investigate the longevity of endocrown restorations, particularly under clinical conditions, and the possible influence of parafunction. Successful adhesive bonding can help to increase the fracture resistance of the restored tooth as well as that of the indirect restoration.[55] It remains a challenge to bond indirect composite restorations to dental hard tissues, because the different interfaces involved (i.e. the interface between the dentin/enamel and adhesive cement and that between the luting agent and the indirect restoration) need to be considered.[43]
Allergy to acrylate in composite in an orthodontic patient: a case report
Published in Journal of Orthodontics, 2018
Sophy K. Barber, Harmeet K. Dhaliwal
The increasing frequency of acrylate allergies has a potentially wider impact on dentistry. Concerns about the safety of amalgam as a dental material, combined with the Minamata Treaty 2013 commitment to reducing mercury in the environment, has increased pressure to seek alternative dental materials (British Dental Association 2017), many of which are acrylate-based. Adhesive bonding is central to minimally invasive restorative techniques. Cosmetic dentistry, orthodontics and laboratory-made prostheses are all heavily reliant on acrylate-containing materials. Biocompatibility issues with acrylates may present complications for treatment planning individual cases and with the provision of dental services as a whole.