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An Introduction to Bioactivity via Restorative Dental Materials
Published in Mary Anne S. Melo, Designing Bioactive Polymeric Materials for Restorative Dentistry, 2020
Mary Anne S. Melo, Ashley Reid, Abdulrahman A. Balhaddad
In the large group of applied dental materials presented in this branch, the bioactive types of cement and antibacterial polymers for dentures have given the step ahead. Luting types of cement are often used to attach dental crowns and bridges in place over prepared abutment teeth. Basic mechanical, biological, and handling requirements must be met by the cement such as not harming the tooth structure or tissues, allow sufficient working time to place the restoration, enough fluidity to allow complete seating of the restoration, must quickly form a hardened mass strong enough to resist functional forces, must not dissolve or wash out, and must maintain a sealed and intact restoration (Hill 2007).
Micromorphology, microstructure and micro-Raman spectroscopy of a case of amelogenesis imperfecta
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
Sebastiana Arroyo Bote, Alfonso Villa-Vigil, M.C. Manzanares Céspedes, Esteban Brau-Aguadé
In a first step of enamel formation, the ameloblasts secrete the organic matrix in which hydroxyapatite crystals are loosely deposited (Mitsiadis & Luder, 2011). Alteration in this stage cause a hypo-plastic enamel. Subsequently, most of the organic matrix is degraded, while the crystals grow in thickness until they have and ordered organization, thus alteration in this phases causes hypomature and hypomineralized enamel. Our RAMAN results showed that indeed in both the altered and the unaffected areas of the AI enamel, the hydroxyapatite crystals present a different orientation when compared with both the dentin and the enamel of a non-AI patient. These alterations are evident both in the fractured and in the depressed enamel lesions, as well as in the apparently healthy enamel surface. Also, Our BS-SEM results show that the enamel prisms of the affected teeth had an irregular size and shape, as well as a different degree of mineralization when compared with control samples. These characteristics are similar to the hypomature type of AI described by Mitsiadis & Lunder (2011). An altered distribution of the enamel prisms has also been described in hypomineralized AI (Sanchez-Quevedo et al., 2006). Moreover, it has been suggest that mutations of AMELX, a gene related to hypomature type of AI, could be present in patients whose phenotype includes fractured dental crowns (Lee et al., 2011), such as the ones visible in our patient.
Oral Health
Published in K. Balamurugan, U. Prithika, Pocket Guide to Bacterial Infections, 2019
Ana Moura Teles, José Manuel Cabeda
Among primary and secondary dentitions as well as in root surface caries, there are significant differences in the oral microbiome’s composition. In the first one, not surprisingly, S. mutans was typically detected at high levels (Becker et al. 2002). Other species like Actinomycesgerencseriae, Scardoviawiggsiae, Veillonella, Streptococcus salivarius, Streptococcus constellatus, Streptococcus parasanguinis, and Lactobacillus fermentum were found in the secondary dentition. The root surface, unlike the dental crown, is not covered by enamel. It was found that the predominant taxa included Actinomyces species, Lactobacillus, Enterococcus faecalis, Mitsuokella sp. HOT131, Atopobium and Olsenella species, Prevotella multisaccharivorax, Pseudoramibacter alactolyticus, and Propionibacterium acidifaciens, although S. mutans was also present with these kind of caries (Preza et al. 2008).
Expression Levels of WNT Signaling Pathway Genes During Early Tooth Development
Published in Organogenesis, 2023
Yuhan Song, Fujie Song, Xuan Xiao, Zhifeng Song, Shangfeng Liu
Dickkopf-related protein 1(Dkk1) is a typical antagonist of Wnt/β-catenin signaling by competing for the Wnt receptor LRP5/6. The mutation of Dkk1 may cause oligodontia and short root anomaly.27,66 Researchers observed that strong expression of Dkk1 was localized in preodontoblasts on the labial side of the incisors.67 At postnatal day 2, Dkk1 is prominently expressed in the preodontoblasts and odontoblasts in mouse molar germs.68 In Dkk1 transgenic mice, overexpression of Dkk1 in pulp and odontoblast cells delayed the maturation of dentinogenesis during post-natal development.69 The dental crown begins to form in the late bell stage (P1). In this stage, peripheral cells of the dental papilla differentiate into odontoblasts that secrete dentin. Our results demonstrated that Dkk1 was significantly expressed in the P1 phase, which indicated that Dkk1 played an important role in the formation of dentin.
Intervention of 3D printing in health care: transformation for sustainable development
Published in Expert Opinion on Drug Delivery, 2021
Sujit Kumar Debnath, Monalisha Debnath, Rohit Srivastava, Abdelwahab Omri
Implant surgeries are performed mechanically. Based on imagination, dentists scan the patient’s jaw and proceed with drilling. Thus, this technique might not be accurate, whereas 3D printing technology is a logical method that locates the best position to drill. With accuracy, it creates the entire denture set that would be able to fit in the mouth. The demand for dental crowns, implants, and bridges is growing high. For customized shape, different 3D printing technologies are used mainly binding jet technology. Several process parameters like binder amount, powder spreading speed, and drying powder level are crucial to getting a customized shape. This technique is also useful to create dentures using metallic powder. Teeth manufacturing with FDM techniques showed accuracy [23]. Processes like SLA, SLS, SLM, and EBM are extremely useful to build a plaster model for the patient’s mouth or replace teeth with less time. Globally, Ti-implants and their bioactive application were explored by using different 3D printing processes. Screw vent implants with porous structures are unique ones.
Inner marginal strength of CAD/CAM materials is not affected by machining protocol
Published in Biomaterial Investigations in Dentistry, 2021
Julia Lubauer, Renan Belli, Fernanda H. Schünemann, Ragai E. Matta, Manfred Wichmann, Sandro Wartzack, Harald Völkl, Anselm Petschelt, Ulrich Lohbauer
In the present study, the mechanical test method developed in Ref. [15] was employed to assess the inner marginal strength of the evaluated materials. To provide for the standardization of the geometrical shape to be machined, a model crown was designed using CAD software based on a metallic abutment with a specific form of a half-sphere with elongated cylindrical margins (Figure 1(a)) to render a sphero-cylindrical object (Figure 1(b,c)) as a crown-like specimen geometry. This shape differs from a dental crown by having a rotational symmetry around its long axis, a 0.5 mm internal margin radius, and a sharp external angle in 90° degrees. This was intended to allow a uniform loading contact around the internal axial wall just below the internal rounded margin and a homogeneous stress state over the inner margin’s circumference. The thickness of the specimens was set to 1.65 mm so to induce the highest marginal stress in the inner margin, the region where clinical marginal fractures are usually located [3,4]. Thinner margins tend to magnify the stress at the outer margins, where chippings at the 90° angle rim affect the failure mode [15].