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

Abstract

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 subgroups 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.

Effect of fluoride varnish on glass ionomer microhardness changes in endogenous acid erosion challenge

“…Dental erosion occurs as the result of exposure of tooth structure to acid attacks without the involvement of microorganisms [ 1 , 2 ]. The reported prevalence of dental erosion varies from 27 to 83% [ 3 ].…”

“…In addition, use of fluoride-containing products has been suggested to inhibit, manage, and treat tooth demineralization that takes place in the process of dental erosion [ 1 , 2 , 9 ]. The availability and accessibility of minerals to reverse the process of demineralization is a concern for patients experiencing repeated erosive challenges, and materials that can be bonded to the tooth surface, such as sealants, varnishes and gels may be more effective for such patients [ 1 , 4 ].…”

“…In addition, use of fluoride-containing products has been suggested to inhibit, manage, and treat tooth demineralization that takes place in the process of dental erosion [ 1 , 2 , 9 ]. The availability and accessibility of minerals to reverse the process of demineralization is a concern for patients experiencing repeated erosive challenges, and materials that can be bonded to the tooth surface, such as sealants, varnishes and gels may be more effective for such patients [ 1 , 4 ]. Products, such as fluoride varnish with high fluoride content and long durability on the tooth surface (12 h) are often the first treatment option against tooth erosion/abrasion challenges due to the deposition of CaF 2 in large amounts [ 1 , 4 , 16 ].…”

“…The availability and accessibility of minerals to reverse the process of demineralization is a concern for patients experiencing repeated erosive challenges, and materials that can be bonded to the tooth surface, such as sealants, varnishes and gels may be more effective for such patients [ 1 , 4 ]. Products, such as fluoride varnish with high fluoride content and long durability on the tooth surface (12 h) are often the first treatment option against tooth erosion/abrasion challenges due to the deposition of CaF 2 in large amounts [ 1 , 4 , 16 ]. The effects of erosive challenges on restorative materials are different from their effects on the tooth structure [ 9 ].…”

“…The effects of erosive challenges on restorative materials are different from their effects on the tooth structure [ 9 ]. Erosion can compromise the mechanical behavior of restorative materials, decrease their hardness, increase their roughness and decrease their longevity and clinical service [ 1 , 9 ]. Pretreatment of restoration surfaces with fluoride varnish has been suggested to enhance their resistance to erosion [ 1 , 17 ].…”