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Interactions between Oral Bacteria and Antibacterial Polymer-Based Restorative Materials
Published in Mary Anne S. Melo, Designing Bioactive Polymeric Materials for Restorative Dentistry, 2020
Fernando L. Esteban Florez, Sharukh S. Khajotia
Over the years, Streptococcus mutans has been considered the most cariogenic among all oral streptococci and has been implicated, by numerous authors, as the leading causative agent of both primary and secondary caries.[9,14]Figure 4.1 displays the image of S. mutans’ biofilm and its main virulence factors linked to the caries disease. However, recent studies applying the pyrosequencing technique to polymerase chain reaction (PCR) products of the 16S rDNA gene have reported that bacterial communities extracted from distinct locations in the oral cavity (smooth, occlusal, or interproximal surfaces) and cavitation stages (shallow, medium, or deep) are comprised of a wide variety of bacterial species.[15,16] In addition, it was also shown that S. mutans only accounts for 1.6% of the total cariogenic biomass found in active carious lesions.[17] Therefore, its role as the primary causative of dental caries (tooth decay) has now been questioned.[18]
Recombinant DNA Technology
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2020
A bacterium having a simple genetic makeup was the first organism to be modified in the laboratory. Bacteria are now used for several purposes and are particularly important in producing large amounts of therapeutic proteins for treating various ailments and diseases, such as the genetically modified (GM) bacteria used to produce the protein insulin to treat diabetes. Similar bacteria have been used to produce clotting factors to treat hemophilia and human growth hormone to treat various forms of dwarfism. In addition to the use of GM bacteria to make therapeutic proteins, GM bacteria are also being used to treat dental disease. For example, tooth decay is caused by the bacteria Streptococcus mutans; these bacteria consume leftover sugars in the mouth, producing lactic acid that corrodes tooth enamel and ultimately causes cavities. Scientists have recently modified Streptococcus mutans so that they do not produce lactic acid. These transgenic bacteria, if properly colonized in a person’s mouth, could reduce the formation of cavities. In recent research, transgenic microbes have also been used to kill or hinder tumors. GM bacteria are also used in some soils to facilitate crop growth and to produce chemicals that are toxic to crop pests.
Contemporary Developments in Nanobiotechnology: Applications, Toxicity, Sustainability, and Future Perspective
Published in Alok Dhawan, Sanjay Singh, Ashutosh Kumar, Rishi Shanker, Nanobiotechnology, 2018
Anubhav Kaphle, Navya Nagaraju, Hemant Kumar Daima
Nanomaterials use in dental practice involve application as dental restorative material, endodontic retro-fill cements, and dental implants. Most dental treatments become a concern when pathological organisms colonize the dentine and enamel, gaps between dentine and enamel and dental restorations, prosthetic materials, and neighboring soft tissue (Rao et al. 2011). Bacteria, in particular Streptococcus mutans and S. lactobacilli, produce acids that can cause extensive dental caries and damage of tissues. It is a real concern when fillings get contaminated with these pathogens. Therefore, the fillings can be treated first with antimicrobials before application. As discussed, metal nanoparticles such as silver particles have an antimicrobial effect with minimal toxicity toward humans, and they can be formulated as coating materials or filling materials. Alginate nanomaterials can also be used as antimicrobial agents (Ahn et al. 2009). However, the addition of these materials should not affect the mechanical properties or hardening behavior of the fillings. Incorporation of silver nanoparticles into bonding adhesives was tried by Moszner et al., and they were successful in maintaining both physical stability and antimicrobial properties (Moszner and Salz 2007). Similarly, Mahmoud and his team managed to synthesize calcium fluoride/fluorinated hydroxyapatite (CF/FHAp) nanocrystals that can be used as osteoconductive dental fillers or implants with antimicrobial activity that can prevent dental caries due to the release of fluorine ions (Azami et al. 2011).
Preliminary Study: Comparative Analysis of the Effects of Ozone and Ultrasound on Streptococcus Mutans
Published in Ozone: Science & Engineering, 2021
Pâmela Maria Moreira Fonseca, Debora Alicia Buendía Palacios, Paulo Luiz de Sá Júnior, Walter Miyakawa, Álvaro José Damião, Adriana Barrinha Fernandes, Carlos José de Lima
Streptococcus mutans produces proteinaceous bactericidal substances to prevail in the low-nutrient ecosystem of the microbial biofilm. These compounds are known as mutacins, and are able to inactivate other species of bacteria of the Streptococcus class and other Gram-positive bacteria, thus allowing S. mutans to colonize and prevail on the ecosystem of the dental biofilm (Kreth et al. 2005; Mota-Meira et al. 2000; Nes, Diep, and Holo 2007; Qi, Chen, and Caufield 1999). Streptococcus mutans is one of the principal microorganisms that exists in the human oral habitat, one of those responsible for the chronic infection that leads to the progressive destruction of dental enamel, specifically characterized as dental cavities (Hasan et al. 2014; Loesche 1986; Metwalli et al. 2013). Ozone (O3) is produced in our planet’s stratosphere due to solar ultraviolet light splitting O2 (Lelieveld and Dentener 2000), resulting in tri-atomic molecules of oxygen (O3). Ozone has an intrinsic characteristic of instability, when it is decomposed in water, free radicals such as hydroxyl and hydrogen peroxide and are formed. These free radicals have strong oxidizing capacities that are able to play a role in the inactivation of microorganisms. There are several studies showing the microbicide ability of ozone (Fonseca et al. 2015; Marson et al. 2016; Passos et al. 2014), the oxidizing effect of which creates gaps in the microbial wall that leads to its inactivation (Fonseca et al. 2019).
Next-generation DNA sequencing of oral microbes at the Sir John Walsh Research Institute: technologies, tools and achievements
Published in Journal of the Royal Society of New Zealand, 2020
Nicholas C. K. Heng, Jo-Ann L. Stanton
For decades, students of the oral health-related professions across the world have been taught that the mutans streptococci (i.e. Streptococcus mutans and related species) cause dental caries and that the development of periodontal disease (periodontitis) is mainly attributed to the Gram-negative bacterium, Porphyromonas gingivalis (Socransky and Haffajee 2005; Paster et al. 2006). As these bacteria, especially the streptococci, are readily cultured in the laboratory and also amenable to genetic modification, the virulence factors of these organisms have been, and still are being, widely-studied. New species, e.g. Scardovia wiggsiae, have since been identified in dental caries lesions (Downes et al. 2011). Similarly, the periodontal pathogens have been categorised into complexes by Socransky (reviewed by Socransky and Haffajee 2005) with P. gingivalis being in the Red complex (high pathogenicity/association) and organisms exhibiting lower pathogenicity, e.g. Aggregatibacter actinomycetemcomitans and Prevotella spp. in the Orange and Yellow complexes.
Mechanical and antibacterial properties of benzothiazole-based dental resin materials
Published in Journal of Biomaterials Science, Polymer Edition, 2018
Wenbin Zhu, Chonghui Lao, Shuzhen Luo, Fang Liu, Qiting Huang, Jingwei He, Zhengmei Lin
Accumulation of acid-producing oral pathogens like Streptococcus mutans (S. mutans) is one of major reasons for caries lesions, because the minerals of dental tissues can be dissolved by acid that released from the bacteria [1]. Nowadays, the missing tooth structure caused by caries is inclined to be restored by dental composites due to their easy handling and aesthetic properties. Unfortunately, compared with other restorative materials like glass ionomer cement and amalgam, dental composites was founded to accumulate more bacteria in vitro [2,3] or in vivo[4,5] studies, for they did not have intrinsic antibacterial activity. Therefore, secondary caries always occurs at the interface between prepared cavity and restorative composites, leading to the failure of treatment [6].