In Vitro Effects of Resin Infiltration on Enamel Erosion Inhibition

Resin-based materials to control human dentin permeability under erosive conditions in vitro: A hydraulic conductance, confocal microscopy and FTIR study

OBJECTIVES

To characterize the behavior of three different polymeric agents before and after an erosive challenge on dentin permeability, to analyze their degradation in both conditions, and to analyze their degree of conversion (DC).

METHODS

The permeability of human dentin disks (1.0 ± 0.2 mm) was measured with smear layer, after its removal, after treatment (LpTreat) with Gluma Desensitizer, PRG Barrier Coat (PBC) or Icon infiltrant (n = 11/group) and after exposure to citric acid (LpEro) (6%, pH 2.1, 1 min). The specimens were analyzed under a Laser Scanning Confocal Microscope (n = 2/group) and the products' DC were calculated. Data were subjected to 2-way repeated measures ANOVA and post-hoc Bonferroni (permeability analysis), to paired t-test (for specimens treated with Icon) and to t-test (DC analysis) (α < 0.05).

RESULTS

Icon showed the lowest LpTreat and LpEro values, while PBC and Gluma did not differ from each other under these conditions. Icon and PBC showed LpEro similar to a dentin with smear layer. Under the Laser Scanning Confocal Microscope, more deposits were noticeable on dentin after treating with PBC. Gluma presented the deepest penetration in dentin. The DC of PBC was the highest.

SIGNIFICANCE

Icon caused the highest reduction on permeability values, followed by PBC and Gluma. PBC generated more deposits covering dentin and seemed to be more efficient after an erosive challenge. The association of a polymeric resin with inorganic ion-releasing fillers seem to be a great strategy to manage dentin hypersensitivity under erosive conditions.

Impact of fluoride-releasing orthodontic adhesives on the shear bond strength of orthodontic brackets to eroded enamel following different surface treatment protocols

PURPOSE:

To assess the impact of enamel surface treatment protocols and the types of adhesive materials on the shear bond strength (SBS) of brackets to eroded enamel substrate.

MATERIALS AND METHODS:

Eighty extracted premolars were randomly assigned to four main groups in which group C (no treatment) was the control group. The remaining groups were exposed to an erosion challenge through short-term acidic exposure to HCl solution (0.01 M, pH 2.3) for 30 s, with an agitation speed of 50 rpm at an environmental temperature of 25°C. The eroded enamel surface within each group was treated as follows: group N received no treatment; in group P, the eroded enamel was treated with 35% phosphoric acid (Ultradent Products, South Jordan, UT, USA) for 15 s, followed by a rinse for 10 s; and in group F, the eroded enamel was treated with fluoride gel (Bifluorid 12; Voco-GmbH, Cuxhaven, Germany) for 4 min. The brackets were bonded with either a resin composite adhesive (Transbond XT; light-cure adhesive, 3M Unitek, CA, USA) or resin-modified glass ionomer cement (Fuji Ortho LC-GC Corporation, Japan). The specimens were tested for SBS, and the bond failure was assessed according to the adhesive remnant index (ARI). Analysis of variance (ANOVA) and Tukey's post-hoc tests (P < 0.05) were used to compare the SBS of the groups. The ARI values between the groups were recorded.

RESULTS:

Statistically significant differences were found among the tested variables (P < 0.05). Group P showed the highest mean SBS values regardless of the type of adhesive used, and the difference was statistically significant (P < 0.05). The application of the fluoride gel showed no statistically significant improvement in SBS values. The failure mode distribution among the test groups indicated that failures at the adhesive–bracket interface were predominant in group C compared with the other study groups.

CONCLUSIONS:

Fluoride pretreatment, which was used to remineralize the eroded enamel surfaces before bonding, resulted in a decrease in the SBS of the orthodontic brackets in vitro compared with the other treated groups. The use of fluoride-releasing adhesive also enhances bonding to the eroded enamel surfaces.

Resin infiltrant protects deproteinized dentin against erosive and abrasive wear

Objectives

This study aimed to investigate the anti-erosive/abrasive effect of resin infiltration of previous deproteinized dentin.

Materials and Methods

Dentin slabs were randomly assigned to 3 groups (n = 15): Control (no deproteinization; no resin infiltrant applied), RI (no deproteinization; resin infiltrant applied), and DRI (deproteinization; resin infiltrant applied). After undergoing the assigned treatment, all slabs were subjected to an in vitro cycling model for 5 days. The specimens were immersed in citric acid (0.05 M, pH = 3.75; 60 seconds; 3 times/day) and brushed (150 strokes). Between the challenges, the specimens were exposed to a remineralizing solution (60 minutes). The morphological alterations were analyzed by mechanical profilometry (µm) and scanning electron microscopy (SEM). Data were submitted to one-way analysis of variance (ANOVA) and Tukey tests (p < 0.05).

Results

Control and RI groups presented mineral wear and did not significantly differ from each other (p = 0.063). DRI maintained a protective layer preserving the dentin (p < 0.001). After erosive/abrasive cycles, it was observed that in group RI, only 25% of the slabs partially evidenced the presence of the infiltrating, while, in the DRI group, 80% of the slabs presented the treated surface entirely covered by a resin-component layer protecting the dentin surface as observed in SEM images.

Conclusions

The removal of the organic content allows the resin infiltrant to efficiently protect the dentin surface against erosive/abrasive lesions.

Comparison of mechanical and optical properties of a newly marketed universal composite resin with contemporary universal composite resins: An in vitro study

The purpose of this study was to evaluate the surface roughness, microhardness, color change, and translucency of a newly marketed universal nanohybrid composite resin (CR) (G-aenial A'CHORD) comparing with four contemporary universal CRs including two nanofilled (Filtek and Estelite Asteria) and two nanohybrid CRs (Charisma Dimond and Neo Spectra ST HV in vitro). Sixty-five specimens (8.0 mm × 2.0 mm) were fabricated (n = 13, per group). After finishing and polishing, specimens were subjected to surface roughness and microhardness tests. Color and translucency of the specimens were evaluated at baseline and after darkening with coffee solution at day 1 and day 7. A representative specimen from each group was investigated under scanning electron microscopy (SEM). Data was analyzed statistically (p < .05). There were significant differences among the groups in terms of surface roughness, microhardness, color, and translucency. The surface roughness was recorded as: Charisma Diamond > Neo Spectra ST HV, Filtek > Estelite Asteria, G-aenial A'CHORD, whereas Vickers Hardness number was as: Filtek, Charisma Diamond > Neo Spectra ST HV > G-aenial A'CHORD, Estelite Asteria. Color change was as: Charisma Diamond > Neo Spectra ST HV, Filtek, G-aenial A'CHORD > Estelite Asteria and the translucency was as: Neo Spectra ST HV > G-aenial A'CHORD, Filtek > Estelite Asteria, Charisma Diamond. SEM examinations revealed smooth surfaces for G-aenial A'CHORD, Neo Spectra ST HV and Estelite Asteria. Mechanical and optical properties of universal composite resins with different compositions show variations.

Effect of Cold Atmospheric Pressure Plasma Coupled with Resin-Containing and Xylitol-Containing Fluoride Varnishes on Enamel Erosion

Purpose

Considering the suggested advantages of cold atmospheric plasma (CAP) in increasing the fluoride uptake by the enamel, this study aimed to assess enamel erosion following the application of helium CAP and two types of fluoride varnishes.

Methods

The microhardness of 70 bovine enamel specimens was measured using a Vickers hardness tester. The specimens were randomly divided into 7 groups (n = 10): control, CAP (P), resin-containing fluoride varnish (RF), CAP + resin-containing fluoride varnish (PRF), fluoride varnish (F), CAP + fluoride varnish (PF), and erosion (E). The specimens in the control and erosion groups did not receive CAP or fluoride varnish. All specimens underwent erosive challenge 4 times/day using hydrochloric acid and artificial saliva except for the control specimens that remained in distilled water during the course of the study. After 5 days of erosive challenge, microhardness was measured again, and the percentage of microhardness change was calculated. Surface roughness of two specimens in each group was assessed by atomic force microscopy (AFM). Data were analyzed using one-way ANOVA followed by Tamhane's post-hoc test.

Results

The percentage of microhardness change in all groups was significantly higher than that of the control group. All groups showed significantly lower percentage of microhardness change compared with the E group except for the P group; no significant difference was noted in microhardness change of P and E groups. Other experimental groups had no significant difference with each other. Surface roughness was the highest in PRF and the lowest in the F group.

Conclusion

CAP application had no significant effect on increasing the enamel resistance to erosion. However, enamel resistance to erosion increased significantly after fluoride varnish application alone or fluoride varnish application combined with CAP. No significant difference was noted between the two types of varnishes in this regard. CAP increased the surface roughness while fluoride varnish application alone decreased the roughness.

Experimental self-etching resin infiltrants on the treatment of simulated carious white spot lesions

OBJECTIVES

To evaluate the penetration depth (μm) of experimental resin infiltrants containing different percentages of triethylene glycol dimethacrylate (TEGDMA) and phosphoric acid 2-hydroxyethyl methacrylate ester (PAM) in artificial carious white spot lesions (WSL).

METHODS

WSL were produced in 65 bovine flat enamel specimens by pH cycling protocol, which were treated with either Icon (control) or experimental acidic infiltrants based on different percentages of TEGDMA and PAM monomers (acidic), and their association or not with previous acid-etching with phosphoric acid. Ten readings using Confocal Laser Scanning Microscopy were conducted on each specimen and the penetration depth was calculated from the surface until the deepest point with the fluorescent dye Rhodamine B (0.02 mg/mL). The pH and the viscosity of the experimental infiltrants were also tested. Data were statistically analyzed with two-way ANOVA and Tukey tests (α < 0.05).

RESULTS

The material factor and the interaction material*acid-etching were statistically significant. The lowest penetration depth was observed for the samples treated with the commercial infiltrant after etching with 15% hydrochloric acid. When specimens were pre-treated with PA, highest penetration was seen for specimens treated with 100% TEGDMA, which differed from all other groups. The lowest penetration was seen for those treated with 50:50 TEGDMA:PAM infiltrants. When specimens were not previously etched, highest penetration was seen for Icon, which differed only from those treated with 25% TEGDMA 75% PAM, where the lowest values were seen. The values of viscosity increased and the pH decreased with the addition of PAM in the infiltrant formulations.

CONCLUSION

the association between TEGDMA and PAM seems to allow similar infiltration depth reached by Icon infiltrant without acid etching the enamel surface.

Color Masking White Fluorotic Spots by Resin Infiltration and Its Quantitation by Computerized Photographic Analysis: A 12-month Follow-up Study

OBJECTIVE

To manage three cases of mild to moderate fluorosis by resin infiltration technique and to quantify the tooth color changes by measuring CIE L*a*b* values of digital photographs and calculating ΔE₀₀ based on the CIEDE2000 formula using Adobe Photoshop software.

METHODS AND MATERIALS

Three cases of mild to moderate fluorosis were treated with a combination of bleaching and a resin infiltration technique. CIE L*a*b* values of 18 fluorosed spots were measured from digital photographs of these cases at four different stages-preoperative, postbleaching, postinfiltration and at 12-month follow-up-using Adobe Photoshop software, and ΔE₀₀ was calculated based on the CIEDE2000 formula. The ΔE₀₀ values of all 18 points obtained at different stages were submitted to statistical analysis (α=0.05).

RESULTS

In all the cases reported, clinically as well as by the photographic color analysis, it was found that the technique masked the lesions, improving the patients' esthetics, which was maintained even at 12-month recall. Statistically significant difference in ΔE₀₀ values was present between comparison of all stages (p<0.001) except between postinfiltration and the 12-month follow-up stage (p=0.642).

CONCLUSION

A resin infiltration technique helped in the satisfactory management of white spot lesions of fluorosis, which were stable even at 12-month follow up. Quantitation of the changes was achieved using Adobe Photoshop software.

Resin-Based Materials Protect Against Erosion/Abrasion-a Prolonged In Situ Study

While patient compliance is key to preventive measures related to dental erosion, the application of resin-based materials could serve as an additional treatment to inhibit erosion progression. This in situ study evaluated the effect of applying resin-based materials, including resin infiltrant, on previously eroded enamel subjected to prolonged erosive and abrasive challenges. The factors under study were types of treatment (infiltrant [Icon], sealant [Helioseal Clear], adhesive [Adper Scotchbond Multi-Purpose Plus], and control [no treatment]); wear conditions (erosion [ERO] and erosion + abrasion [ERO + ABR]) and challenge time (5 and 20 days) in a single-phase study. The blocks were prepared from bovine enamel, eroded (0.01 M HCl, pH 2.3 for 30 seconds) and randomized among treatments, wear conditions, and volunteers. The application of resin-based materials followed the manufacturers' recommendations. Twenty-one volunteers wore the palatal intraoral device, in which one row corresponded to ERO and the other to ERO + ABR. In each row, all treatments were represented (2 blocks per treatment). For 20 days, the erosive challenge was performed 4 times/day (immersion in 0.01 M HCl, pH 2.3, for 2 minutes) for the ERO condition. For the ERO + ABR condition, two of the erosive challenges were followed by abrasion for 15 seconds with fluoride dentifrice slurry. Enamel and/or material loss was measured using profilometry (initial, after treatment, and after the end of the fifth and 20th days of in situ erosive challenge) and analyzed by ANOVA models and Tukey's test (α=0.05). The results showed that the application of resin-based materials did not cause superficial enamel loss. The infiltrant group showed a thicker layer of material above the enamel compared with the other materials (p=0.001). After the erosive challenge, there was no difference between the conditions ERO and ERO + ABR (p=0.869). All materials protected the enamel against erosion progression compared with the control group (p=0.001). Based on these results, we conclude that the application of resin-based materials results in protection of previously eroded enamel subjected to in situ erosive and abrasive challenge for 20 days.

Impact of a simplified in situ protocol on enamel loss after erosive challenge

This study investigated the effect of the period of use and location of intraoral appliances on enamel surface loss. This randomized, single blind in situ study was conducted in 2 crossover phases based on the period of use, in which maxillary and mandibular appliances were simultaneously worn. Bovine enamel blocks (n = 120) were randomly divided among the studied groups by surface hardness. In each phase, fifteen volunteers used one maxillary appliance and two mandibular appliances for 5 days. Erosive challenge was performed 4X/day by immersion in 0.01 M HCL for 2 minutes. In the continuous phase, the intraoral appliances were worn for 20 hours. In the intermittent phase the appliances were worn for 8 hours and 30 minutes. Enamel loss was determined profilometrically. The discomfort of use of the appliances were evaluated in a questionnaire. Data were analyzed by two-way ANOVA/Tukey’s test and chi-square test (p<0.05). The maxillary appliance promoted higher enamel loss compared to the mandibular one (p<0.001). Intermittent use of appliances resulted in similar enamel loss to the continuous one (p = 0.686). All volunteers preferred to use the maxillary appliance in an intermittent regimen. The intermittent use of maxillary appliance is a simplified reliable protocol appropriated for in situ erosion studies in enamel.

Application of the Self- Assembling Peptide P11-4 for Prevention of Acidic Erosion

The aim of this study was to use ultrasonography to evaluate the effect of the self-assembling peptide P11-4 on acid erosion prevention. Curodont Repair (CR), which includes peptide P11-4, was used. Rectangular prisms of bovine enamel (4×1×1 mm) were immersed in pure orange juice for a period of 5 minutes six times per day for 28 days. These samples were divided into four groups of six specimens each and treated differently for an additional period of 28 days: 1) baseline group specimens were stored in artificial saliva; 2) CR group specimens were exposed to curodont without acid challenge; 3) NCRA (no curodont+acid challenge) specimens were treated with orange juice without curodont exposure; and 4) CRA (CR+acid challenge) specimens were treated with curodont before treatment with orange juice. The propagation time of longitudinal ultrasonic velocity (UV) was measured. Ultrastructural observation of each tested enamel surface was carried out using field-emission scanning electron microscopy (SEM). The UV data were analyzed using two-way analysis of variance with time and treatment as confounding factors. Post hoc pairwise tests among groups were performed using the Tukey honestly significant difference test. The average UV in intact bovine enamel for the baseline group ranged from 4,483 to 4,549 m/s and did not vary significantly within the test period. The average ultrasonic velocity (UV) in all samples decreased after the initial erosion. The UV in NCRA decreased further over time. Increased UVs were found for CR and CRA. For CR and CRA, there was no significant difference in UV at the end of the experiment from the initial value before erosion. In the results of SEM observation, the CR and CRA groups had similar morphologic features in that etching patterns were not clearly due to precipitation between the enamel rods. From the results of this in vitro study, it might be concluded that applying enamel matrix derivatives and self-assembling peptides on erosive lesions can improve remineralization.

Susceptibility of bovine dental enamel with initial erosion lesion to new erosive challenges

This in vitro study evaluated the impact of initial erosion on the susceptibility of enamel to further erosive challenge. Thirty bovine enamel blocks were selected by surface hardness and randomized into two groups (n = 15): GC- group composed by enamel blocks without erosion lesion and GT- group composed by enamel blocks with initial erosion lesion. The baseline profile of each block was determined using the profilometer. The initial erosion was produced by immersing the blocks into HCl 0.01 M, pH 2.3 for 30 seconds, under stirring. The erosive cycling consisted of blocks immersion in hydrochloric acid (0.01 M, pH 2.3) for 2 minutes, followed by immersion in artificial saliva for 120 minutes. This procedure was repeated 4 times a day for 5 days, and the blocks were kept in artificial saliva overnight. After erosive cycling, final profile measurement was performed. Profilometry measured the enamel loss by the superposition of initial and final profiles. Data were analyzed by t-test (p<0.05). The result showed no statistically significant difference between groups (GS = 14.60±2.86 and GE = .14.69±2.21 μm). The presence of initial erosion on bovine dental enamel does not enhance its susceptibility to new erosive challenges.

Microhardness and Roughness of Infiltrated White Spot Lesions Submitted to Different Challenges

A white spot lesion is the first clinical sign of a caries lesion and represents mineral loss from the enamel subsurface. The purpose of this study was to evaluate the microhardness and surface roughness of white spot lesions after application of a resin infiltrant and subjection to different challenges. Caries-like lesions were induced in bovine enamel discs (n=50), and the specimens were randomly divided into five study groups (n=10): demineralized enamel (negative control, G1), infiltrated enamel (G2), infiltrated enamel submitted to brushing (G3), infiltrated enamel submitted to pH cycling (G4), and infiltrated enamel submitted to artificial aging (G5). Half of each enamel surface was used as its own positive control. Roughness data were analyzed using the Kruskal-Wallis test followed by the Dunn test. Results from microhardness were analyzed by two-way analysis of variance, followed by the Tukey test for multiple comparisons. The level of significance was set at 5%. Microhardness and roughness values obtained from the test side of the specimens were significantly lower compared with the sound enamel for all groups. Microhardness values obtained for G2, G3, and G5 were not significantly different. Values found for G1 were significantly lower compared with those for G2, G3, and G5. The lowest microhardness values were observed for G4, which was significantly different from the other groups. Surface roughness was not significantly different between G2 and G3. The resin infiltrant presented superiority over the unprotected white spot lesions, as they were more resistant to mechanical and aging challenges. However, resin infiltration was not able to reestablish the properties of sound enamel and was not resistant to a new cariogenic challenge.

Bond strength and interfacial morphology of orthodontic brackets bonded to eroded enamel treated with calcium silicate-sodium phosphate salts or resin infiltration

OBJECTIVE

 To investigate the shear bond strength (SBS) of orthodontic brackets bonded to eroded enamel treated with preventive approaches and to examine the enamel/bracket interfaces.

MATERIALS AND METHODS

 Ninety-one brackets were bonded to seven groups of enamel samples: sound; eroded; eroded+treated with calcium silicate-sodium phosphate salts (CSP); eroded+infiltrated by ICON^®; eroded+infiltrated by ICON^® and brackets bonded with 1-month delay; eroded+infiltrated by an experimental resin; and eroded+infiltrated by an experimental resin and brackets bonded with 1-month delay. For each group, 12 samples were tested in SBS and bond failure was assessed with the adhesive remnant index (ARI); one sample was examined using scanning electron microscopy (SEM).

RESULTS

 Samples treated with CSP or infiltration showed no significant differences in SBS values with sound samples. Infiltrated samples followed by a delayed bonding showed lower SBS values. All of the values remained acceptable. The ARI scores were significantly higher for sound enamel, eroded, and treated with CSP groups than for all infiltrated samples. SEM examinations corroborated the findings.

CONCLUSIONS

 Using CSP or resin infiltration before orthodontic bonding does not jeopardize the bonding quality. The orthodontic bonding should be performed shortly after the resin infiltration.

Treatment of Fluorosis Spots Using a Resin Infiltration Technique: 14-month Follow-up

The aim of this study was to report a clinical case of moderate fluorosis spots treated with infiltration of low-viscosity resin. A commercial resin was applied to the facial surfaces on the anterior teeth in both the maxillary and mandibular arches. The white spots of fluorosis lost their whitish appearance and appeared similar to sound enamel. This technique, which might constitute an alternative to white-masking of fluorosis spots, showed optimal esthetic results.

Evaluation of sorption/solubility, softening, flexural strength and elastic modulus of experimental resin blends with chlorhexidine

OBJECTIVES

To evaluate physical-chemical properties of experimental diacetate chlorhexidine (CHX)-added resin blends.

METHODS

Blends were formulated: G1)TEGDMA; G2)TEGDMA/0.1%CHX; G3)TEGDMA/0.2%CHX; G4)TEGDMA/UDMA; G5)TEGDMA/UDMA/0.1%CHX; G6)TEGDMA/UDMA/0.2%CHX; G7)TEGDMA/BisEMA, G8)TEGDMA/BisEMA/0.1%CHX; G9)TEGDMA/BisEMA/0.2%CHX. Icon(®) was the control group. For sorption/solubility (SS), cylindrical specimens (n=5) were prepared and their weight obtained. The specimens were immersed in deionized water for 7days at 37°C and their weight was verified again. SS were calculated using accepted formulas. For softening, cylindrical specimens (n=10) were prepared and initial Knoop hardness number (KHN) obtained. The specimens were immersed in absolute ethanol for 24h at 37°C and final KHN accomplished. Softening values were calculated by KHN reduction percentage. For elastic modulus (EM) and flexural strength (FS) bar specimens were prepared (n=10) and values obtained with a universal device (three point, 5mm distance, 0.5mm/min, load of 50N). The data was analyzed using one-way ANOVA and Tukey test (α=5%).

RESULTS

TEGDMA/BisEMA blends and Icon(®) showed the lowest sorption from blends (p>0.05), and Icon(®) was the most soluble material (p<0.01). TEGDMA/UDMA/0.1%CHX showed the highest softening, similar to Icon(®) (p>0.05). For EM, all blends were different than Icon(®) (p<0.01). For FS, TEGDMA blends were similar to Icon(®), showing the lowest averages (p>0.05).

CONCLUSIONS

Monomers chemical characteristics influenced the physical-chemical properties of experimental blends more than CHX. Between the blends tested, UDMA blends presented satisfactory results for assays evaluated.

CLINICAL SIGNIFICANCE

Infiltrants CHX-added could arrest and reinforce initial caries lesions, and the antimicrobial effect could prevent new lesions in sound enamel adjacent to the infiltrated area.

Effectiveness of resin-based materials against erosive and abrasive enamel wear

OBJECTIVE

The objective of this study was to test the effectiveness of resin-based materials against erosive enamel wear under erosive and abrasive challenges by orange juice and tooth brushing.

METHODS

Fifty enamel specimens from third molars were assigned to five groups: ICON resin infiltration with no etching (ICON-NE), ICON resin infiltration with 15 % HCl etching (ICON-AE), Seal & Protect sealant (S&P), Tetric EvoFlow (TEF), and control. Erosive lesions were first created on enamel, then treated with resin-based materials. Erosive and abrasive challenges by orange juice and tooth brushing were repeated after treatments. Erosive wear of the treated areas was measured with 3D scanning microscopy, and data were analyzed using ANOVA and paired t tests.

RESULTS

Treatments with ICON, S&P, and TEF created a protective material coating of 4.5 ± 1.9 μm, 44.3 ± 8.1 μm, and 84.6 ± 15.7 μm in thickness on the lesion surfaces, respectively. After 15 cycles of erosive and abrasive challenges, enamel or material losses were 21.9 ± 2.3 μm for control, 24.5 ± 4.0 μm for ICON-NE, 24.6 ± 7.4 μm for ICON-AE, 11.2 ± 4.1 μm for S&P, and 3.9 ± 1.9 μm for TEF, respectively. The protective coatings were completely lost in the ICON infiltration groups but remained intact in both the S&P and TEF groups after erosive and abrasive challenges.

CONCLUSION

In contrast to a resin sealant and a flowable composite, ICON infiltration resin was not effective in protecting enamel surfaces from erosive and abrasive wear.

CLINICAL RELEVANCE

Sealant and flowable composite resin may create protective coatings on eroded enamel surfaces and prevent further tissue loss.

Influence of removing excess of resin-based materials applied to eroded enamel on the resistance to erosive challenge

OBJECTIVES

The aim of this study was to evaluate the effect of removing excess of resin-based materials applied to eroded enamel, subjected to erosive challenge.

METHODS

Bovine enamel blocks were immersed in HCl 0.01M, pH 2.3, for 30s under agitation at 50 rpm in room temperature, in order to form a softened erosion lesion. The blocks were then randomly divided into eight groups (n=12) and treated as follows: Cn- and Ce-control without treatment, Hn- and He-fissure resin sealant (Helioseal Clear(®)), An- and Ae-self-etch adhesive (Adhese(®)), In- and Ie-infiltrant (Icon(®)); being n-with excess removal and e-without excess removal of the material. After application of the materials, the blocks were immersed in HCl for 2 min, followed by immersion in artificial saliva for 120 min. This cycle was repeated four times a day for five days. Material thickness and enamel wear were assessed using profilometry. Data were analyzed by two-way ANOVA and Tukey's test (P<0.05).

RESULTS

Groups He, Ae, and Ie resulted in the formation of a layer of material over enamel, being similar effective in inhibiting erosion progression (P>0.05). Groups Hn, An, and In (with excess removal) were similar to controls (Cn, Ce) and resulted in near enamel loss after application and after erosive challenge (P>0.05).

CONCLUSIONS

Resin-based materials are able to protect enamel against erosion only when they are present over enamel, as a physical barrier.

CLINICAL SIGNIFICANCE

The resin-based materials demonstrated potential to prevent the progression of erosion lesions when the material remains on the dental surface.