In Vitro Effects of Resin Infiltration on Enamel Erosion Inhibition

Abstract

Resin-based materials that show promising effects for preventing the progression of erosion have been studied. This in vitro study evaluated the effects of applying resin-based materials, including resin infiltration, on previously eroded enamel subjected to erosive challenges. The influence of enamel surface etching prior to application of the material was also studied. Bovine enamel blocks were immersed in hydrochloric acid (HCl), 0.01 M (pH 2.3), for 30 seconds in order to form a softened erosion lesion. The blocks were then randomly divided into nine groups (n=12) and treated as follows: C = control without treatment; Hel = pit & fissure resin sealant (Helioseal Clear); Adh = two-step self-etching adhesive system (AdheSe); Tet = two-step conventional adhesive system (Tetric N-bond); and Inf = infiltrant (Icon). The Helno, Adhno, Tetno, and Infno groups received the same materials without (or with no) surface conditioning. The depth of the material's penetration into softened erosion lesions was qualitatively analyzed using reflection and fluorescence confocal microscopy. After application of the materials, the blocks were immersed in HCl for two minutes; this step was followed by immersion in artificial saliva for 120 minutes four times a day for five days (erosive cycling). Both the enamel alteration and material thickness were analyzed using profilometry, and the results were submitted to Kruskal-Wallis and Dunn tests (p>0.05). Images from the confocal microscopy showed minimal penetration of Adh/Adhno and deep penetration of Inf/Infno into the erosive lesions. The groups Hel, Adh, Inf, Tetno, and Infno resulted in the formation of a layer of material over the enamel, which was effective in inhibiting the progression of erosion. In conclusion, the infiltrant, with or without etching, was able to penetrate and protect the enamel against dental erosion. The other resin-based materials, except for the two-step conventional adhesive, were able to penetrate and inhibit the progression of erosive lesions only when they were applied after enamel etching.

Penetration of resin‐based materials into initial erosion lesion: A confocal microscopic study

“…In previous study, it was observed on sound and carious enamel that infiltrant alone presented higher loss of apatite than adhesive and adhesive + infiltrant in lactic acid for 21 days (Schmidlin et al, ). Another study found that infiltrant and resin sealant remained over the eroded enamel and offered protection even after erosive challenges (HCl for 2 min—four times/day) for 5 days (Oliveira et al, ). Despite the positive outcomes achieved for application of infiltrant and resinous sealant in dental erosion, further in vitro and in situ studies are necessary to evaluate the retention and durability of these materials in enamel and dentin before they might be applied for clinical purpose.…”

“…The application of resin-based materials has been studied as an alternative for minimally invasive treatment of erosion lesions (Buzalaf et al, 2014). Resin sealants, dental bonding agents and infiltrant were able to protect the tooth against erosive challenge by forming a mechanical layer over the enamel (Azzopardi et al, 2001(Azzopardi et al, , 2004Bartlett et al, 2011;Oliveira et al, 2015;Sundaram et al, 2007;Wegehaupt et al, 2013). The penetration of resin-based materials is very important for material's durability, such as their adhesion to the dental structure and their resistance to oral degradation (Buonocore et al, 1968;Kugel and Ferrari, 2000).…”

“…Initial Erosive Lesion. Bovine enamel blocks were subjected to short-term acidic exposure by immersing in 0.01 M hydrochloric acid solution (Merck, Darmstadt, Germany), pH 2.3, for 30 seconds (17.6 mL per block), resulting in surface softening (Oliveira et al, 2015).…”

“…Despite the differences between caries and erosion lesions (Honório et al, ) it was hypothesized that infiltrant could penetrate into the initial erosion lesion forming a mechanical barrier against the action of erosive acids. In a recent study performed in vitro it was observed that the infiltrant material and resin sealant were effective to inhibit the progression of erosion lesion exposed to short‐term erosive cycling (Oliveira et al, ). It is known that penetration can affect adherence of the materials to the dental structure (Buonocore et al, ; Kugel and Ferrari, ).…”

Impact of Saliva and Intraoral Appliance on Erosion Lesions Rehardening Ability -A Pilot Study

“…Fluoride and alternatives to fluoride for the prevention and treatment of dental erosion has been suggested based on scientific data originated from in vitro and in situ studies [15,[21][22][23]. However there is no standardized protocol for in situ studies, additionally the influence of the area of the mouth in which the removable appliance is located and the ideal period between erosive challenges on the rehardening of eroded enamel is unknown.…”