Effect of photoactivation on the reduction of composite resin contamination

Abstract

Composite resins are predominantly marketed in developing countries in tube form, and the contents of the tube may be used in numerous procedures for different patients. This represents a problem because of the risk of cross-contamination. This study aimed to evaluate contamination in vitro of the internal contents of composite resin tubes in the dental clinics of a higher-education institution, as well as the effect of photoactivation on the level of contamination. Twenty-five tubes containing composite resin were randomly chosen (by lottery). From each tube, two samples of approximately 2 mm of composite resin were removed, and then one sample, but not the other, was photoactivated. These samples were plated on Brain-Heart Infusion (BHI), Sabouraud and MacConkey agars, and the plates were incubated at 37°C for 24-48 h. Colony counting and Gram staining were performed for subsequent microscopic identification of fungi and bacteria. The non-photoactivated composite resin group presented significantly higher microbial contamination in relation to the photoactivated composite resin group. The photoactivation of camphorquinone present in composite resin produces reactive oxygen species, which might promote cell death of contaminant microorganisms. Thus, although the same tube of composite resin may be used for a number of different patients in the dental clinics of developing countries, the photoactivation process potentially reduces the risk of cross-contamination.

Desenvolvimento de instrumental para a padronização do volume e da forma dos incrementos de resina composta direta e relato de caso clínico

“…O risco de contaminação das resinas compostas dá-se através do contato direto, onde o operador pode contaminar o tubo e a resina com o instrumental ou com as luvas (23,24). No estudo realizado por Pauletti et al (25), 32% dos tubos avaliados estavam contaminados. O instrumental desenvolvido no presente estudo pode ser uma forma de eliminar a contaminação cruzada, tendo em vista que a espátula que entra em contato com o tubo de resina não é a mesma que entra em contato com a boca do paciente.…”

Cross‐infection control in clinical training: Development of a device for storing a composite resin in restorative dentistry

“…During clinical training, dental students come into direct contact with patients and should therefore be made aware of the risks of cross‐infection in dental practice (Al‐Maweri et al, ; Pauletti, Girotto, Leite, & Mario, et al, ). Educational institutions are responsible for technically preparing their students and making them aware of their responsibilities with regard to cross‐infection control practices in dentistry (Westall & Dickinson, ), which are based on internationally adopted protocols (Centers for Disease Control and Prevention, ).…”

“…Composite resin is an aesthetic restorative material widely used in restorative dentistry in syringe form (Pauletti, et al, ). In educational institutions, these resin syringes are generally shared by several students and their content is used on several patients, which could increase the risk of cross‐infection due to contamination of the external part of the syringe or its contents (Pauletti, et al, ; Batista, et al ; Oliveira, Barreto, Salgado, Chaves Filho, & Diniz, ). Thus, a simple restorative procedure can become a potential cross‐infection chain, in which microorganisms, both normal microbiota and etiological disease agents, from the first patient are transmitted to the next patient, and so on (Werle, Santo, & Dotto, ).…”