Anti-Caries Effects of Dental Adhesives Containing Quaternary Ammonium Methacrylates with Different Chain Lengths

Abstract

The objectives of this study were to investigate the effects of dental adhesives containing quaternary ammonium methacrylates (QAMs) with different alkyl chain lengths (CL) on ecological caries prevention in vitro. Five QAMs were synthesized with a CL = 3, 6, 9, 12, and 16 and incorporated into adhesives. Micro-tensile bond strength and surface charge density were used to measure the physical properties of the adhesives. The proportion change in three-species biofilms consisting of Streptococcus mutans, Streptococcus sanguinis, and Streptococcus gordonii was tested using the TaqMan real-time polymerase chain reaction. Lactic acid assay, MTT [3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, exopolysaccharide staining, live/dead staining, scanning electron microscopy (SEM), and transverse microradiography (TMR) were performed to study the anti-biofilm and anti-demineralization effects of the dental adhesives. The results showed that incorporating QAMs with different alkyl chain lengths into the adhesives had no obvious effect on the dentin bond strength. The adhesives containing QAMs with a longer alkyl chain developed healthier biofilms. The surface charge density, anti-biofilm, and anti-demineralization effects of the adhesives increased with a CL of the QAMs from 3 to 12, but decreased slightly with a CL from 12 to 16. In conclusion, adhesives containing QAMs with a tailored chain length are promising for preventing secondary caries in an “ecological way”.

Self-disinfecting surfaces and infection control

“…This fact gives these polymers ultra-hydrophilicity and consequently great hydration ability [70,71]. Studies concerning surface modification with zwitterionic polymers have proved to be a promising strategy to reduce microorganisms' adhesion [72,73]. Very recently, a study using a tyramine-conjugated sulfobetaine polymer, grafted on polyurethane showed a great reduction in S. aureus adhesion to the surface [74].…”

The Antibacterial Effects of Quaternary Ammonium Salts in the Simulated Presence of Inhibitors in Root Canals: A Preliminary In-Vitro Study

“…This unique antibacterial mechanism made QAMs effective against a wide range of microbes and also minimized the possibility of the development of resistance by microbes. Two recently developed QAM compounds, dimethylaminododecyl methacrylate (DMADDM) and dimethylaminohexadecyl methacrylate (DMAHDM), were proven to be more effective than conventional QAMs [11][12][13][14][15][16][17]. The resistance against aging is an added benefit of these novel compounds which makes them remain active for a longer duration and inhibit bacterial colonization.…”

Avaliação do efeito antibacteriano e da citotoxicidade de um adesivo com nanopartículas de prata e sua resistência de união à dentina associado ao uso de nanopartículas de hidroxiapatita

“…A cárie secundária é a principal causa para substituição de restaurações (3,5,6,12,23,24,26,27,34,36,40,41). Esta é uma doença infecciosa sacarosedependente que ocorre em interfaces previamente restauradas(42) e os microrganismos responsáveis pelo seu surgimento são os mesmos envolvidos na cárie primária (42).…”

“…Diante de uma odontologia minimamente invasiva e cada vez mais conservadora, é preconizada a remoção da dentina infectada e a dentina afetada é deixada no fundo da cavidade, o que pode resultar em bactérias residuais após preparo cavitário (3, 5, 23, 24, 26, 34, 36, 45-47, 51, 52). É estimado que de 50 a 70% dos procedimentos restauradores ocorrem para substituição de restaurações deficientes, devido a presença de cáries secundárias (12,23,24,26,47). Então, lançar mão de mecanismos que possam inibi-las torna-se primordial para promover maior longevidade das restaurações diretas em resina composta.…”

“…O mecanismo de ação da prata ainda não foi completamente elucidado (31)(32)(33) (5,12,46,48,55,69,75), ou com um microcosmo (3,8,17,23,24,26,27,34,40,41), no qual, geralmente a saliva humana é utilizada como inóculo, pois simula mais fielmente o ambiente oral (3,8,26,27,40,41). As análises podem ser realizadas em microrganismos tanto na forma planctônica ( citotóxicos, e o menor grau de conversão de monômeros em polímeros têm relação direta com a lixiviação dos componentes adesivos e toxicidade ao meio (91).…”