Can surface protection prevent the loss of hardness on dentin and composite resin surfaces exposed to erosive challenges?

• Main Authors: Patricia Akemi Nishitani Shibasaki, Janaina Emanuela Damasceno, Mariana Menezes Vaz de Queiroz, Max José Pimenta Lima, Roberto Paulo Correia de Araújo, Richard Mark Foxton, Andrea Nóbrega Cavalcant
• Format: Article
• Language: English
• Published: Universidad de Concepción. 2020-04-01
• Series: Journal of Oral Research
• Subjects: tooth erosion; hardness; dentin; glass ionomer cements; composite resins; hydrochloric acid
• Online Access: http://www.joralres.com/index.php/JOR/article/view/joralres.2020.021/714

Objective: This study investigated the effect of endogenous erosion on the microhardness of dentine and a nanofilled composite resin. Procedures for preventing erosion were also studied. Materials and Methods: 90 bovine dentine specimens were divided into three groups in accordance with the method for preventing: negative control, topical application of fluoride and resin-modified glass ionomer varnish. 120 composite resin specimens were distributed into four groups, which also included a resin sealant, among the preventive procedures. Specimens were then randomly divided into three sub-groups according to the exposure to simulate gastric acid solution and subsequent remineralization: negative control, 9 and 18 cycles. Surface analysis was carried out by measuring the Knoop hardness. The data obtained were statistically analyzed using 2-way ANOVA and Tukey test. Result: The mean hardness of dentine and of the composite specimens resin exhibited lower hardness after 18 cycles. However, the resin-modified glass ionomer varnish resulted in greater values compared to the other preventive procedures. Conclusion: A resin-modified glass ionomer varnish seems to be a promising method for minimizing the damage caused by endogenous acid, but its protection can be reduced depending on the intensity of the erosive challenge.