Color Properties of Demineralized Enamel Surfaces Treated with a Resin Infiltration System

The influence of the addition of titanium oxide nanotubes on the properties of 3D printed denture base materials

INTRODUCTION

In this study, the effects of adding titanium dioxide nanotubes (TiO2) to 3D-printed denture base resin on the mechanical and physical properties of denture bases were examined for the first time.

METHODS

The specimens were digitally created using 3D builder software from Microsoft Corporation through computer-aided design. In accordance with the test specifications for transverse strength, impact strength, hardness, surface roughness, and color stability, specimens were designed and printed with certain dimensions following relevant standards. TiO2 nanotubes (diameter: 15-30 nm and length: 2-3 μm) were added to the 3D-printed denture base resin (DentaBase, Asiga, Australia) at 1.0% and 1.5% by weight. Flexural strength, impact strength (Charpy impact), hardness, surface roughness, and color stability were evaluated, and the collected data were analyzed with ANOVA followed by Tukey's post hoc test (α = 0.05). Field emission scanning electron microscopy (FESEM) and energy dispersive x-ray spectroscopy (EDX) mapping were used to evaluate the dispersion of the nanotubes.

RESULTS

Compared with those of the control group (0.0 wt.% TiO2 nanotubes), the average flexural, impact, and hardness values of the 1.0 and 1.5 wt.% TiO2 nanotube reinforcement groups increased significantly. Both nanocomposite groups showed significant color changes compared to that of the pure resin, and there was a considerable reduction in the surface roughness of the nanocomposites compared to that of the control group.

CONCLUSION

Adding TiO2 nanotubes to 3D-printed denture base materials at 1.0 and 1.5 wt.% could enhance the mechanical and physical properties of the material, leading to better clinical performance.

CLINICAL SIGNIFICANCE

In terms of clinical applications, 3D-printed denture base material has been shown to be a viable substitute for traditional heat-cured materials. By combining this with nanotechnology, existing dentures could be significantly enhanced, promoting extended service life and patient satisfaction while addressing the shortcomings of the current standard materials.

Surface topography and spectrophotometric assessment of white spot lesions restored with nano-hydroxyapatite-containing universal adhesive resin: an in-vitro study

BACKGROUND

White spot lesion (WSL) is a main shortcoming accompanied by orthodontic treatment. It impairs the esthetic, surface hardness, and surface texture of enamel. So, this study was conducted to analyze the surface characteristics and color change of white spot lesions treated with nano-hydroxyapatite (nHA)-enriched universal adhesive resin.

MATERIALS AND METHODS

Eighty sound human permanent molars crowns were sectioned into two halves, producing 160 specimens. 16 specimens were left untreated, and 144 specimens were artificially-demineralized to generate WSLs. The specimens were classified according to the treatment approach applied as follows: I; Sound enamel, Group II; artificially-created WSLs, Group III; ICON resin-restored WSLs, Group IV; Universal adhesive resin-restored WSLs, Group V; 0.5 wt% nHA-containing universal adhesive resin-restored WSLs, Group VI; 1 wt% nHA-containing universal adhesive resin- restored WSLs, and Group VII; 3 wt% nHA-containing universal adhesive resin-restored WSLs, Group VIII; 5 wt% nHA-containing universal adhesive resin-restored WSLs, Group IX; 7 wt% nHA-containing universal adhesive resin-restored WSLs, and Group X; 10 wt% nHA-containing universal adhesive resin-restored WSLs. Some surface characteristics and color changes were assessed. Data was collected and analyzed statistically using ANOVA and the Tukey test at p < 0.05.

RESULTS

Surface microhardness of WSLs was significantly improved with all investigated ratios of nHA-containing universal adhesive (p < 0.0001), with the highest mean belonging to 10 wt% nHA-containing universal adhesive resin treated WSLs. All ratios of nHA-containing universal adhesive resin significantly reduced the surface roughness of WSLs (p < 0.0001). The investigated ratios of 1, 3, 5, 7, and 10 wt% nHA-containing universal adhesive resin treatment approach could mask the WSLs significantly (p < 0.0001).

CONCLUSIONS

Nano-hydroxyapatite-containing universal adhesive is a promising contemporary approach for the management of WSLs, coupled both the remineralizing concept and the minimally invasive resin infiltration.

Making white spots disappear! Do minimally invasive treatments improve incisor opacities in children with molar-incisor hypomineralisation?

BACKGROUND

Children with molar-incisor hypomineralisation (MIH) frequently seek aesthetic treatment for incisor opacities. Surprisingly, few studies have evaluated the clinical success of such interventions.

AIM

To quantify the effectiveness of minimally invasive treatments in reducing enamel opacity visibility in children with MIH.

DESIGN

This in vitro study used digital clinical images of 23 children aged 8-16 years with MIH who underwent microabrasion and/or resin infiltration for the management of incisor opacities. Standard images were taken pre-treatment and 6 months post-treatment. Image software (Image-Pro Plus^® V7) was employed to convert 24-bit RGB images to 16-bit greyscale and 145× magnification. Measurement repeatability was assessed using intra-class correlation coefficients (ICCs). Post-treatment changes in visible opacity area (mm² ) and brightness (greyscale value) were tested using the Wilcoxon signed-rank test for related samples.

RESULTS

The mean total opacity surface area significantly reduced from 14.3 mm² (SD = 7.5) to 9.4 mm² (SD = 9.0) post-treatment. The proportion of tooth surface affected by the opacity also significantly reduced from 22.5% (SD = 10.5) to 14.7% (SD = 12.7). The mean maximum opacity brightness significantly reduced from 53 066 greyscale value (SD = 4740) to 49 040 (SD = 3796). ICC was good/excellent (0.75-1.0).

CONCLUSION

Minimally invasive treatment is effective in reducing the size and brightness of discrete incisor opacities. Future research should compare objective findings with patient-reported outcomes.

In-vivo colour stability of enamel after ICON® treatment at 6 years of follow-up: a prospective single center study

OBJECTIVES

This in-vivo clinical study provides subjective and objective documentation on colour stability of enamel after resin infiltration at a mean observation time of six years after treatment.

METHODS

76 teeth previously treated with ICON® due to hypomineralized lesions of enamel were recalled for a follow-up at ………(………..). Colour stability was assessed: i) subjectively by patients using FDI-colour matching criteria; ii) objectively by calculating CIEDE2000 colour differences between the affected/treated and sound enamel in each tooth at T0 (baseline), T1 (one year) and T2 (six years) based on spectrophotometric data. Analysis of correlation between FDI and CIEDE2000 data was performed.

RESULTS

Two teeth were lost to follow-up prior to 72 months. No unwanted effects were reported by patients. Number of FDI scores 1 and 2 were 13.5%, 90.6% and 93.2% at T0, T1 and T2, respectively. ΔE00 was evaluated at 6.8 (SD3.8) at T0. ΔE00 was 5.8 (SD3.1) between T0 and T1 and 1.3 (SD0.6) between T1 and T2. ΔE00 reduction (T1-T0) was significantly but only fairly correlated with FDI scores at any follow-up.

CONCLUSIONS

This study shows that caries infiltration satisfactorily masks aesthetically relevant lesions after longer follow-up. Subjective and objective outcomes showed a fair correlation mainly for the initial masking effect.

CLINICAL SIGNIFICANCE

This prospective clinical trial demonstrates the excellent subjective and objective colorimetric stability of enamel treated with ICON® 6 years after treatment.

Colour stability of 3D-printed resin orthodontic brackets

OBJECTIVE

To evaluate the colour stability of polymeric resins that could be used to 3D-print orthodontic brackets.

DESIGN

In vitro, laboratory study.

MATERIALS AND METHODS

Disc-shaped specimens were fabricated via 3D printing using three resins: Dental LT; Dental SG; and Clear. Five conditions were evaluated for each resin (n = 10 per treatment per resin) to assess its corresponding effect on colour and translucency: immersion in (1) red wine, (2) coffee, (3) tea and (4) distilled water (control), and (5) exposure to accelerated aging. Colour and translucency measurements were made before and after exposure using a spectrophotometer. Mean colour differences (ΔE₀₀) and changes in translucency parameter (ΔTP₀₀) were calculated for each sample using the CIEDE2000 colour difference formula.

RESULTS

Statistically significant effects of the resin material, the treatment condition and interactions effects of material and condition were observed for ΔE₀₀ and ΔTP₀₀ (P < 0.001). The most pronounced changes in colour (ΔE₀₀) were a result of the staining effects of wine on all three resins, ranging from 14.5 ± 0.6 to 20.8 ± 1.2. Dental LT, Dental SG and Clear resins all showed changes in colour when exposed to certain staining agents. Dental SG and Clear resins exhibited changes in colour with aging, while the colour of Dental LT resin remained stable with aging.

CONCLUSIONS

The colour changes of the resins investigated does not support their use in 3D-printed aesthetic bracket applications.

Response of pulp cells to resin infiltration of enamel white spot-like lesions

OBJECTIVES

To investigate the trans-enamel and trans-dentinal biological effects of treating enamel white spot-like lesions (EWSLs) with resin infiltration components (RICs) on odontoblast-like cells (MDPC-23) and human dental pulp cells (HDPCs).

METHODS

EWSLs were induced in 60 enamel/dentin discs (4.0 ± 0.2 mm thick) using S. mutans. The discs were adapted into artificial pulp chambers and MDPC-23 were seeded on the dentin surface. The components of a resin infiltration system (Icon) were applied individually or in combination on the enamel surface as following (n = 10/treatment): Etch, Infiltrant, Etch+Infiltrant, or Etch+Dry+Infiltrant. The application of water or hydrogen peroxide served as negative and positive controls, respectively. After 72 h, MDPC-23 viability was evaluated. The extracts were exposed for 72 h to pre-cultured MDPC-23 and HDPCs in 96-well plates to evaluate cell viability, alkaline phosphatase activity (ALP), mineralized nodule formation (MN), and the expression of inflammatory cytokines (ICs) and mineralization-related genes (MRs). Data were analyzed by ANOVA complemented with Tukey or Games-Howell post-hocs (α = 5%).

RESULTS

Cell viability, ALP activity, and MN formation were significantly reduced in response to the RICs, presenting intermediate values compared to positive and negative controls. Likewise, ICs were upregulated, whereas MRs were downregulated. Among the RICs, the Etch component caused the most notorious detrimental effects.

SIGNIFICANCE

Resin infiltration of EWSLs negatively affected the metabolism of pulp cells in vitro. Therefore, even though resin infiltration is a micro-invasive therapy for non-cavitated caries in enamel, it should be closely followed up seen that components may diffuse and unbalance pulp homeostasis.

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.

Enamel around orthodontic brackets coated with flash-free and conventional adhesives

OBJECTIVE

To evaluate enamel roughness and color after debonding flash-free adhesive precoated brackets and brackets coated with conventional orthodontic adhesives using nonbonded enamel as control.

MATERIALS AND METHODS

A total of 80 extracted human premolars were divided into the following four groups: group I: APC^TM Flash-Free adhesive precoated brackets; group II: APC^TM PLUS adhesive precoated brackets; group III: noncoated brackets, which were coated manually at the time of bonding (all three brackets were Clarity^TM Advanced ceramic brackets [3M Unitek, Monrovia, CA, USA]); group IV: nonbonded enamel (control). Bonded premolars were subjected to demineralization, and then brackets were debonded. Each group was then divided into two subgroups to assess enamel around the debonded brackets, and also enamel in the control group, using an atomic force microscope and spectrophotometer. In addition, 12 samples were used to assess the bracket/adhesive/enamel junction with a scanning electron microscope.

RESULTS

Mean values of root mean square roughness (Rq) and maximum profile valley depth (Rv) for APC^TM Flash-Free, APC^TM PLUS, and Clarity^TM Advanced groups were 140 nm and 482 nm, 210 nm and 727 nm, and 447 nm and 1243 nm, respectively. All three groups showed higher roughness and depth values than the control enamel. Spectrophotometer results yielded ∆E* of 3.7 ± 0.6, 5.1 ± 0.4, and 7.1 ± 0.6 for APC™ Flash-Free, APC™ PLUS, and Clarity^TM Advanced groups respectively. Color coordinates showed progressively higher L* and b* values and progressively lower a* values from group I to group III.

CONCLUSIONS

Under the same demineralization conditions, enamel around debonded APC™ Flash-Free adhesive precoated brackets showed less roughness and color changes compared to the other two groups.

The Efficacy of Resin Infiltrant and Casein Phosphopeptide-amorphous Calcium Fluoride Phosphate in Treatment of White Spot Lesions (Comparative Study)

Background:

White spot lesions (WSLs) are considered as the first sign of the progression of dental caries that can be reversed. Casein phosphopeptide–amorphous calcium fluoride phosphate (CPP-ACFP) varnish can promote remineralization process of the demineralized tooth structure. Also, WSLs can be managed by using caries infiltrant (ICON), which infiltrates etched enamel surface of the WSLs.

Objectives:

The main aim was to evaluate and compare the efficacy of ICON versus CPP-ACFP varnish to treat WSLs in the same oral environments.

Materials and Methods:

A total of 30 participants aged 20–40 years with at least two WSLs have participated in this trial. Split-mouth technique has been used in this trial where WSLs on the left side have been treated with ICON, whereas WSLs on the right side have been treated with CPP-ACFP varnish. Clinical evaluation using DIAGNOdent was carried out at baseline, 1 week, 1, 3, 6, and 12 months after application to determine the effectiveness of these materials in treating WSLs.

Results:

Significant differences were observed between all follow-up DIAGNOdent scores compared to baseline readings of both ICON and CPP-ACFP (P = 0.000 for all comparisons). Statistically significant differences were observed between DIAGNOdent scores of ICON compared to CPP-ACFP at all follow-up intervals (P = 0.006, 0.008, 0.045, 0.036, and 0.000).

Conclusion:

Both ICON and CPP-ACFP were effective in the treatment of WSLs of smooth surfaces but the efficacy of CPP-ACFP was better than ICON.

The Influence of Dental Occlusion on Spectrophotometric Tooth Color Determinations

Background:

Shade matching is a significant treatment step and a challenge for the clinical team with potentially high costs for color correction. Currently, in the United States, the majority of private dental practitioners use visual color matching, but a recent study has reported a high rate of mistakes of subjective color determination among graduate dentists.

Objective:

The aim of this retrospective study is to analyze whether a change in the oral background due to dental occlusion can influence tooth color determination.

Methods:

Volunteer dental students underwent spectrophotometric color assessment using the SpectroShade device. Two measurements were carried out (with the individuals’ occlusion closed and with the occlusion open) on 43 upper central and 58 lateral incisors. Association between colorimetric variables L*, a*, b* and ΔE00 and tooth width, length and tobacco usage were examined.

Results:

Slight changes in the CIELAB values between closed and open occlusions were found for both the gingival and the central sections as for the overall tooth area, with mean ΔL*=-1.24, Δa*=-1.77, Δb*=-1.42 and ΔE00=1,84. A larger difference was detected in the incisal area, with mean ΔL*=-2.99, Δa*=-1.76, Δb*=-2.83 and ΔE00=3.65.

Conclusion:

In conclusion, our study showed that dental occlusion does not play a significant role in tooth color matching determinations, even though attention to avoid overbite due to a maximum intercuspation should be made.

Evaluation of color changes of white spot lesions treated with three different treatment approaches: an in-vitro study

Objective:

To qualitatively and quantitatively assess the color changes effect and the color stability of the resin infiltrant on white spot lesions (WSLs), in comparison with nano-hydroxyapatite (nano-HA) toothpaste and microabrasion.

Methods:

WSLs were artificially created on sixty human premolars enamel surfaces and randomly assigned to equal four groups (n = 15 each): nano-HA toothpaste, microabrasion (Opalusture), resin infiltrant (Icon) treatment, or artificial saliva (control group). The color change (ΔE) of each specimen was measured by dental spectrophotometer (Vita Easyshade) at different time points: baseline, after WSLs’ creation, after application of treatments, one month, three and six months after treatments application.

Results:

The ΔE value did not differ significantly for the four groups at baseline measurement before treatment (p> 0.05). Icon resin infiltrant improved the color of WSLs significantly immediately after its application, giving the lowest ΔE value (3.00 ± 0.59), when compared to other treatments (p< 0.001). There were no significant changes in ΔE (p> 0.05) for all groups during the follow up intervals (one month, three and six months after treatments application).

Conclusion:

Resin infiltrant can improve the color of WSLs and restore the natural appearance of enamel better than nano-HA toothpaste and microabrasion.

The Use of Resinous Infiltrants for the Management of Incipient Carious Lesions: a Literature Review

AbstractThe objective of this work was to analyze scientific evidence from a literature review pertaining to the effectiveness of resinous infiltrants for minimally invasive treatment of incipient carious lesions. Studies published between 2002 and 2019 were queried from the following databases: Capes, PubMed, Medline, BBO, Lilacs and SciELO. The search keywords included "Dental Caries", "Tooth Remineralization", "Dental Leakage". Most of the studies found resin-infiltrating treatment to be a viable option for the minimally invasive treatment of incipient carious lesions; this treatment was able to fulfill the primary expected effects: inhibition of carious progression and the lesions esthetic improvement. However, some issues need to be clarified to improve the safety of this treatment because it can be recommended in clinical practice. In conclusion, the use of resinous infiltrants has been reported as promising for the treatment of incipient carious lesions. However, there is a need for long-term studies to confirm the effectiveness of this treatment to determine its applicability for clinical use. Keywords: Dental Caries. Dental Leakage. Tooth Remineralization. ResumoO objetivo desse trabalho foi analisar evidências científicas, por meio de uma revisão de literatura, sobre a eficácia do uso de infiltrantes resinosos para o tratamento minimamente invasivo de lesões cariosas incipientes. A seleção do material literário utilizado foi realizada por pesquisa sobre o tema nas bases de dados: portal de periódicos Capes, PubMed, Medline, BBO, Lilacs e SciELO, abrangendo prioritariamente, o período de 2002 a 2019. Para busca nas bases de dados foram utilizadas palavras-chave como “Cárie Dentária”, “Remineralização Dentária”, “Infiltração Dentária”, assim como suas correspondentes na língua inglesa.  A maioria dos estudos encontrados aponta o tratamento infiltrante resinoso como uma opção viável para o tratamento minimamente invasivo de lesões cariosas incipientes sendo capaz de cumprir os principais efeitos esperados: inibição da progressão cariosa e melhoria estética das lesões. Entretanto, alguns impasses necessitam ser esclarecidos para que o tratamento seja recomendado com mais segurança na prática clínica. Conclui-se que o uso de infiltrantes resinosos tem sido relatado como promissor para o tratamento de lesões cariosas incipientes, contudo há necessidade de novas pesquisas e estudos a longo prazo para confirmar sua eficácia em todos aspectos desejáveis para seu uso clínico. Palavras-chave: Cárie Dentária. Infiltração Dentária. Remineralização Dentária.

Assessing the Appearance and Fluorescence of Resin-Infiltrated White Spot Lesions With Caries Detection Devices

OBJECTIVE

This in vitro study examined the effectiveness of caries detector devices in assessing the ability of resin infiltration (RI) (Icon, DMG-Hamburg, Hamburg, Germany) to improve the optical properties of enamel white spot lesions (WSLs).

METHODS AND MATERIALS

Ten caries-free third molars were used. Photographs, a subjective visual assessment of the photographs, fluorescent camera (FC) images using the Spectra (Air Techniques, Melville, NY, USA), and laser fluorescent (LF) readings using the DIAGNOdent (KaVo, Biberach, Germany) were obtained from each tooth's buccal surface. Specimens were coated with nail polish leaving a rectangular window on the buccal surface and placed in pH 4.5 lactic acid gel for two weeks to create a WSL. The WSLs were analyzed by the same methods. RI was applied to half of each WSL; final photographs were then taken, and caries detector assessments were conducted. FC images were converted to grayscale, and the fluorescent image's brightness intensity was measured using ImageJ. Data were analyzed with analysis of variance and Tukey-Kramer honestly significant difference test. Significance was set at α=0.05.

RESULTS

Subjective assessment of the photographs showed that RI improved the appearance of the WSLs so that they resembled intact enamel. Mean FC-brightness intensities for intact, demineralized, and demineralized RI-treated areas were 159.6 ± 9.2, 123.4 ± 7.2, and 160.9 ± 11.5, respectively. There were no significant differences in fluorescent intensity between the intact and RI areas ( p=0.58). The demineralized areas had significantly lower fluorescent intensity than both the RI-treated and intact areas ( p<0.001). LF values did not differ significantly between intact, demineralized, or RI-treated areas.

CONCLUSIONS

This study demonstrates the ability of RI to restore artificial WSLs to the esthetics and fluorescence of intact enamel. The FC can be used to assess the optical properties of WSLs and the impact of RI on these properties.

Objective and subjective aesthetic performance of icon® treatment for enamel hypomineralization lesions in young adolescents: A retrospective single center study

OBJECTIVES

An evaluation method is proposed to qualitatively and quantitatively evaluate the clinical outcome of the enamel hypomineralization treatment with infiltrative resin in young adolescents. The aesthetic outcome is assessed before and after treatment by visual evaluation using FDI-colour match criteria and by spectrophotometric analysis using the CIEDE2000 colour difference formula. The visual (subjective) results are compared with the spectrophotometric (objective) approach.

MATERIALS AND METHODS

76 teeth of patients of Sapienza University (Rome, Italy) presenting early caries lesions and/or developmental defect of enamel on the labial surface of clinical crown were subjected to resin infiltration. Three observers evaluated the aesthetic appearance of the teeth before and after treatment using FDI-colour match criteria. The spectrophotometric colour difference between the affected and sound enamel in each tooth was calculated before and after resin infiltration. A correlation between FDI criteria and the calculated CIEDE2000 colour difference (ΔE₀₀) was performed.

RESULTS

Mean FDI scores and ΔE₀₀, evaluated before and after treatment, were large in all sample. A clear correlation was detected between visual inspections and spectrophotometric colour difference of clinical outcomes.

CONCLUSIONS

On the basis of the present study results, the aesthetic outcome of resin infiltration proved to be highly effective, both with visual qualitative and spectrophotometric quantitative assessment.

CLINICAL RELEVANCE STATEMENT

Hypomineralized enamel colour abnormalities affect patients' quality of life, therefore tissue preservative cosmetic treatments are requested. An evaluation method of resin infiltration clinical outcome by visual evaluation and spectrophotometry is proposed.