The Potential Role of Ionic Liquid as a Multifunctional Dental Biomaterial

In craniofacial research and routine dental clinical procedures, multifunctional materials with antimicrobial properties are in constant demand. Ionic liquids (ILs) are one such multifunctional intelligent material. Over the last three decades, ILs have been explored for different biomedical applications due to their unique physical and chemical properties, high task specificity, and sustainability. Their stable physical and chemical characteristics and extremely low vapor pressure make them suitable for various applications. Their unique properties, such as density, viscosity, and hydrophilicity/hydrophobicity, may provide higher performance as a potential dental material. ILs have functionalities for optimizing dental implants, infiltrate materials, oral hygiene maintenance products, and restorative materials. They also serve as sensors for dental chairside usage to detect oral cancer, periodontal lesions, breath-based sobriety, and dental hard tissue defects. With further optimization, ILs might also make vital contributions to craniofacial regeneration, oral hygiene maintenance, oral disease prevention, and antimicrobial materials. This review explores the different advantages and properties of ILs as possible dental material.

Conservative esthetic management of brown enamel fluorosis using combination therapy: A clinical report

Dental fluorosis is caused by ingestion of excessive fluoride during tooth development resulting in hypomineralization of the enamel and can present as white or brown intrinsic lesions. This case report describes a combination of minimally invasive techniques: microabrasion, bleaching, and resin infiltration to address brown enamel fluorosis present on the maxillary anterior teeth of a young patient. Before resin infiltration, air microabrasion was targeted at subsurface lesions located on the maxillary central and lateral incisors, and chairside bleaching was done with 37% hydrogen peroxide (Opalescence). After which, hypoplastic lesions on the buccal surfaces were etched before being treated with two sessions of resin infiltration (ICON and DMG). Following treatment, satisfactory esthetic outcomes were achieved. Accurate diagnosis, depth of lesions, and understanding the effectiveness and limitations of each technique are essential to select the appropriate type of treatment to obtain the best esthetic outcome. In conclusion, the conservative management of varying severity of dental fluorosis may require the appropriate use of combination treatment modalities, such as microabrasion, bleaching and resin infiltration, when clinically indicated, to address the treatment needs and achieve a desired outcome.

An Insight into Enamel Resin Infiltrants with Experimental Compositions

Resin infiltration is a conservative treatment of initial enamel carious lesions. Only one infiltrant material is available on the market (Icon, DMG), and research is now investigating new chemical compositions so as to further exploit the benefits of the resin infiltration technique. A literature search of the articles testing the effects of different formulations on mechanical properties, resin penetration ability, remineralizing, and antibacterial activities was conducted. Of 238 articles, 29 resulted in being eligible for the literature review. The formulations investigated were all different and consisted in the inclusion of hydrophobic monomers (i.e., BisEMA, UDMA), solvents (ethanol, HEMA), alternative etchants (PAM) or molecules with antibacterial or bioactivity features (i.e., AgNP, YbF_3, MTZ, chitosan, DMAMM, HAp, MC-IL, NACP, PUA, CHX) and microfilled resins. Information on the long-term performances of the tested experimental materials were scarce. The combination of TEGDMA with hydrophobic monomers and the inclusion of a solvent alternative to ethanol reinforced mechanical properties of the materials. Hybrid-glass materials demonstrated an enhanced remineralization capacity. Techniques such as tunnelization increased the penetration depth and preserved the recourse to less-conservative treatments. Combining the min-invasive infiltrant approach with remineralizing and bacteriostatic properties would be beneficial for therapeutic and economical aspects, according to the principles of minimally invasive dentistry.

Resin Infiltration of Non-Cavitated Enamel Lesions in Paediatric Dentistry: A Narrative Review

The resin infiltration (RI) technique was introduced as one of the minimal intervention dentistry strategies in addressing dental caries among the paediatric population. This technique used the low-viscosity resin monomer to infiltrate the non-cavitated carious lesion and other developmental enamel porosities, thus allowing the conservation of the tooth structure. This narrative review aims to explore the value of RI in Paediatric Dentistry. Through our search of the literature, the development of the material, their clinical applications and shortcomings, as well as the innovation that has been carried out to improve the current RI, were discussed. There are number of high-level evidence supporting the use of RI in arresting non-cavitated proximal caries lesions in primary and permanent teeth, but its efficacy in managing anterior white spot lesions is still unclear. Limited penetration depth, not radiopaque and questionable long-term colour and material stability were among the limitation of the material. Various laboratory-based studies have been conducted to improve the current properties of RI. Nevertheless, RI has emerged as one of the important micro-invasive techniques in addressing non-cavitated and anterior white-spot enamel lesions in children and adolescents with great success.

Casein phosphopeptide amorphous calcium phosphate and universal adhesive resin as a complementary approach for management of white spot lesions: an in-vitro study

Background

White spot lesion (WSL) is the most common consequence during and after orthodontic treatment. This study was conducted to investigate the ability of casein phosphopeptide amorphous calcium phosphate (CPP-ACP) coupled with universal adhesive resin to treat white spot lesions.

Material and methods

Forty-five extracted premolars were sectioned to create 90 specimens. Seventy-five specimens were demineralized to generate artificially created WSLs. Different strategies have been applied for the management of the artificially created WSLs. Six experimental groups were employed: Group I: sound enamel (control), Group II: demineralized enamel (artificially-created WSLs), Group III: ICON resin-treated WSLs, Group IV: CPP-ACP-treated WSLs, Group V: universal adhesive resin-treated WSLs, and Group VI: CPP-ACP followed by universal adhesive resin-treated WSLs. Assessment of color stability using a spectrophotometer, surface microhardness using a Vickers tester, and surface roughness using a profilometer was done. The surface topography of representative specimens from each experimental group was inspected using a scanning electron microscope. Collected data were analyzed using one-way ANOVA followed by Tukey’s post hoc test at p ≤ 0.05.

Results

White spot lesions treated with CPP-ACP and subsequently coated with universal adhesive resin (Group VI) exhibited a significantly lower ΔE than both CPP-ACP (Group IV) and universal adhesive resin-treated (Group V) groups (p ≤ 0.05), but it was not significantly different from the ICON resin-treated group (Group III). For surface microhardness, WSLs treated with CPP-ACP and consequently coated with universal adhesive resin (Group VI) recorded the highest mean that was significantly different from both ICON resin (Group III) and universal adhesive resin-treated (Group V) groups (p ≤ 0.05). All the tested strategies (ICON resin, CPP-ACP, universal adhesive resin, and CPP-ACP followed by universal adhesive resin) significantly lowered the surface roughness of the WSLs (p ≤ 0.05), while no significant difference was detected among them.

Conclusions

Combining a considerable caries remineralizing program using CPP-ACP with subsequent universal adhesive resin infiltration could be a promising approach to manage WSLs efficiently through increasing surface microhardness and restoring esthetic while developing a smoother surface.

Nonrestorative treatment of initial caries lesion in primary teeth: a systematic review and network meta-analysis

OBJECTIVE

To identify the best available approach to avoid initial caries lesions progression in primary teeth.

MATERIALS AND METHODS

Search was performed in MEDLINE/Pubmed, Web of Science, Embase and CENTRAL databases until March 2021. Studies compared treatment options to avoid the initial caries lesion progression with at least 12 months of follow-up were included. Network meta-analyses were conducted considering the non-progression of caries lesions as an outcome.

RESULTS

Potentially eligible studies were screened (n = 2820) and eleven were included. Six studies evaluated the use of fluoride varnish, resin infiltration, sealing, and toothbrushing/flossing on proximal initial caries lesions. When considering occlusal surfaces, only two studies evaluating the ozone gas, fluoride varnish, resin infiltration, and sealants were included. For buccal/lingual surfaces, three studies evaluating toothbrushing, CPP-ACP paste, fluoride varnish, and resin infiltration were included. For all types of surfaces, the resin infiltration showed the best probability to avoid the progression of initial caries lesions.

CONCLUSION

The limited number of included studies, most with a high risk of bias and lack of hard outcomes, such as frank cavitation, makes it not feasible to recommend a specific management approach for initial caries lesion control in primary teeth with a high certainty of evidence. PROSPERO: #CRD42016037781.

Histomorphometric Evaluation of Socket Preservation Using Autogenous Tooth Biomaterial and BM-MSC in Dogs

This study is aimed at assessing the dimensional alterations occurring in the alveolar bone after premolar extraction in dogs with histomorphometric and histological analysis. After atraumatic premolar extraction, tooth-derived bone graft material was grafted in the extraction socket of the premolar region in the lower jaws of six dogs in two experimental groups. In the second experimental group, BM-MSCs were added together with the graft. The control was left untreated on the opposite side. After twelve weeks, all six animals were sacrificed. Differences in alveolar bone height crests lingually and buccally, and alveolar bone width at 1, 3, and 5 mm infracrestally, were examined. Histologic study revealed osteoconductive properties of tooth biomaterial. A statistically significant difference was detected between the test and control groups. In the test groups, a reduced loss of vertical and horizontal alveolar bone dimensions compared with the control group was observed. Tooth bone graft material may be considered useful for alveolar ridge preservation after tooth extraction, as it could limit the natural bone resorption process.

Ionic liquid-loaded microcapsules doped into dental resin infiltrants

Resin infiltrants have been effectively applied in dentistry to manage non-cavitated carious lesions in proximal dental surfaces. However, the common formulations are composed of inert methacrylate monomers. In this study, we developed a novel resin infiltrant with microcapsules loaded with an ionic liquid (MC-IL), and analyzed the physical properties and cytotoxicity of the dental resin. First, the ionic liquid 1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf₂) was synthesized. BMI.NTf₂ has previously shown antibacterial activity in a dental resin. Then, MC-IL were synthesized by the deposition of a preformed polymer. The MC-IL were analyzed for particle size and de-agglomeration effect via laser diffraction analysis and shape via scanning electron microscopy (SEM). The infiltrants were formulated, and the MC-IL were incorporated at 2.5%, 5%, and 10 wt%. A group without MC-IL was used as a control. The infiltrants were evaluated for ultimate tensile strength (UTS), contact angle, surface free energy (SFE), and cytotoxicity. The MC-IL showed a mean particle size of 1.64 (±0.08) μm, shriveled aspect, and a de-agglomeration profile suggestive of nanoparticles' presence in the synthesized powder. There were no differences in UTS among groups (p > 0.05). The incorporation of 10 wt% of MC-IL increased the contact angle (p < 0.05), while the addition from 5 wt% reduced the SFE in comparison to the control group (p < 0.05). The human cell viability was above 90% for all groups (p > 0.05). The incorporation of microcapsules as a drug-delivery system for ionic liquids may be a promising strategy to improve dental restorative materials.

•

Ionic liquid was used as core of synthesized polymeric-based microcapsules.

•

Microcapsules doped with ionic liquid were incorporated into a dental resin.

•

The dental resins presented proper mechanical and biocompatibility properties.

•

The particles incorporation reduced the surface free energy of dental resins.

•

Biointeractivity may be obtained through MC-IL addition into dental resins.

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.

Low-Viscosity Resin Infiltration Efficacy on Postorthodontic White Spot Lesions: A Quantitative Light-Induced Fluorescence Evaluation

Objective

The aim of this in vivo study was to evaluate the efficacy of low-viscosity light-cured resin infiltration on postorthodontic white spot lesions (WSLs) on incipient and advanced lesions using quantitative light-induced fluorescence (QLF).

Methods

The study subjects were patients with clinically diagnosed postorthodontic WSLs (n=57). QLF images of the lesions were obtained using a QLF device (Inspektor-Pro, Amsterdam, The Netherlands) before any treatment. Images were processed using the built-in software (QLF patient v2.0.0.48), which produced fluorescence loss (ΔF¹), lesion area (Area¹), and impact (ΔF₁ x Area₁, ΔQ₁) values. Lesions were categorized as incipient (-5<ΔF₁<-12, n=14) or advanced (-12<ΔF₁<-25, n=43). They were then infiltrated with low-viscosity resin (Icon-DMG, Hamburg, Germany) according to the manufacturer's instructions. QLF imaging was repeated (ΔF₂, Area₂, and ΔQ₂) from the same aspects assured by the relative software. Kolmogorov-Smirnov, Wilcoxon, and Mann-Whitney tests were used for data evaluation.

Results

ΔF₁ (-8.40±0.73) and Area₁ (3.44±5.19) decreased to -6.58±0.88 and 0.18±0.33 for incipient lesions (p<0.001 and p=0.002, respectively). ΔF₁ (-13.20±5.32) and Area₁ (4.71±5.56) decreased to -7.51±2.7 and 0.29±1.86 for advanced lesions (p<0.001). When ΔF, lesion area, and ΔQ changes between the groups were compared, the decrease in ΔF was greater for advanced lesions (p<0.001), whereas the decrease in the lesion area and ΔQ was similar (p=0.690, p=0.291).

Conclusions

Infiltration treatment provides improvement of WSLs in terms of fluorescence loss, lesion area, and impact for both incipient and advanced lesions, with the latter group presenting higher fluorescence loss reduction.

Anti-caries effect of resin infiltrant modified by quaternary ammonium monomers

OBJECTIVES

Resin infiltrant is used in early enamel caries. However, commercial resin infiltrant lacks persistent antibacterial activity. Dimethylaminododecyl methacrylate (DMADDM) was added to resin infiltrant to give it sustainable antibacterial properties and inhibit demineralization.

METHODS

After the application of resin infiltrant to bovine enamel, cytotoxicity, surface roughness, and aesthetics were assessed. A multi-species biofilm was incubated on the enamel disk before and one month after microbial-aging. After a 48-h anaerobic incubation, biomass accumulation, metabolic activity, and lactic acid were analyzed using a crystal violet assay, an MTT (3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, and a lactic acid assay. Biofilm structure and composition were determined by live/dead staining, exopolysaccharide (EPS) staining, scanning electron microscopy (SEM), and quantitative polymerase chain reaction (qPCR). The depth and content of demineralization were tested by transverse microradiography (TMR).

RESULTS

Incorporating DMADDM did not increase the cytotoxicity or change the physical properties when the mass fraction of the DMADDM was 2.5-10 %. The modification decreased the amount of bacterial biofilm, metabolic activity, lactic acid production, EPS, and the proportion of Streptococcus mutans in the biofilms. It also provided anti-demineralization effects. The surface roughness and antibacterial ability were not changed after one month of microbial-aging.

CONCLUSION

The incorporation of DMADDM improved the antibacterial and anti-demineralization effects of the material. It demonstrated a sustained antibacterial effect.

CLINICAL SIGNIFICANCE

The antibacterial modification might be a potential choice for future clinical applications to inhibit early enamel caries.

Effect of Resin Infiltration Technique on Improving Surface Hardness of Enamel Lesions: A Systematic Review and Meta-analysis

OBJECTIVE

White spot lesion (WSL) is recognized as the first clinical sign of enamel caries; it is a very critical phase because it can be prevented from progression to frank caries by changing the surrounding destructive environment. The present study was undertaken to systematically review the effect of resin infiltration (RI) technique on surface hardness (SH) of WSL.

METHODS

Five electronic databases were searched with proper key words. Related titles and abstracts, up to October 2018, were screened, selected, and subjected to quality assessments. After collecting data, meta-analyses were carried out to compare the effect of RI with untreated WSL and sound enamel by using the STATA software.

RESULTS

A total of 4567 articles were included in the study after initial search. Finally, 10 studies were reliable enough in methodology to be included in the study. Metadata analyses, carried out on 7 studies that compared SH of RI group with untreated samples, showed a significant increase in SH with 3.66 mean difference (95% confidence interval = 2.56‒4.77, Q value = 36.07, I² = 83.4%). However, meta-analysis on 4 studies that compared SH of RI with sound enamel showed a significant decrease in SH with -2.35 overall mean difference (95% confidence interval = -3.91-0.98, P = .00, Q value = 31.75, I² = 90.6%).

CONCLUSION

The RI technique can enhance SH of WSL; however, regaining the SH of RI-treated WSLs similar to sound enamel is doubtful. Application of RI is more effective than other methods, including application of fluoride, enamel pro-varnish, adhesive, and colloidal silica infiltration for enhancing SH of WSLs.

Comparative Evaluation of Microhardness and Enamel Solubility of Treated Surface Enamel with Resin Infiltrant, Fluoride Varnish, and Casein Phosphopeptide-amorphous Calcium Phosphate: An In Vitro Study

Aim and objective

The aim and objective of this study was to do a comparative evaluation of microhardness and enamel solubility (ES) of the treated surface enamel with resin infiltrant, fluoride varnish, and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP).

Materials and methods

An in vitro study was conducted on freshly extracted 85 sound permanent teeth of which 5 teeth were subjected to check for microhardness by the Vickers microhardness tester and the remaining teeth were exposed to demineralizing solution to create initial enamel lesions. These 80 teeth were assigned to four groups: group I—negative control (n = 20), group II—resin infiltrant (n = 20), group III—fluoride varnish (n = 20), and group IV—CPP-ACP (n = 20), and microhardness was checked after application. These teeth were exposed to caries attack three times a day for three consecutive days. The ES of these four groups was checked by calcium ion loss in the artificial cariogenic solution and whole saliva by an atomic absorption spectrophotometer.

Results

It was found that none of the experimental groups reached the microhardness values of sound intact teeth. At 3rd day, the values of microhardness were: group II = group III > group IV > group I. Maximum ES was found for group I (control) followed with group IV.

Conclusion

All agents used in study remineralized initial carious lesion. Fluoride varnish has the highest microhardness and showed least ES compared to other remineralizing agents.

Clinical significance

Fluoride varnish can be regarded as the choice of material to be used for the treatment of incipient carious lesions because of the low application frequency (once every 3–6 months), requires minimal patient compliance as it is a noninvasive procedure and less time consuming.

How to cite this article

Dhillon SN, Deshpande AN, Macwan C, et al. Comparative Evaluation of Microhardness and Enamel Solubility of Treated Surface Enamel with Resin Infiltrant, Fluoride Varnish, and Casein Phosphopeptide-amorphous Calcium Phosphate: An In Vitro Study. Int J Clin Pediatr Dent 2020;13(S-1):S14–S25.

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.

Resin infiltration of enamel white spot lesions: An ultramorphological analysis

OBJECTIVE

There is not a clear understanding of the ultramorphology of enamel white spot lesions (WSLs). The purpose of this study is to characterize resin infiltration of enamel WSLs using electron microscopy.

MATERIALS AND METHODS

Enamel sections with sound enamel and WSLs were sectioned from extracted teeth and assigned to three groups: (a) left untreated; (b) etched with 15% hydrochloric acid (Icon-Etch); (c) restored with the resin infiltration sequence (Icon-Etch, Icon-Dry, and Icon-Infiltrant). Restored specimens were demineralized to obtain replicas. Observations were carried out under a field-emission scanning electron microscope.

RESULTS

Icon-Etch resulted in an array of pits and funneled holes on the WSL. Replicas of WSLs depicted 0.5-6.0-μm-thick shaggy resin tags up to a depth of 465 μm. Enamel crystallites were enveloped with resin at the bottom of the WSL forming a hybrid layer.

CONCLUSIONS

The resin infiltrant filled the spaces between the crystallites and resulted in an enamel hybrid layer.

CLINICAL SIGNIFICANCE

In addition to masking enamel WSLs, resin infiltration is able envelop residual enamel crystallites forming an enamel hybrid layer. This hybridization makes resin-embedded enamel more resistant to acid attack than sound enamel.

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.

Randomized controlled clinical trial of resin infiltration in primary molars: 2 years follow-up

OBJECTIVE

The aim of this split-mouth, randomized, controlled clinical trial was to evaluate the efficacy of resin infiltration in controlling the progression of non-cavitated proximal lesions in primary molars after two-years follow-up.

METHODS

Fifty healthy children presenting at least two primary molars with proximal lesion detected radiographically (in the inner half of enamel or the outer third of dentin) were included in the study. The proximal lesions were randomly allocated into resin infltration + flossing (test group) or flossing (control group). All patients received oral hygiene instructions for daily brushing with fluoride toothpaste (1100 ppmF) and flossing. The proportion of caries progression was compared using the McNemar test. The main outcome after 2-years, caries progression in the radiography was assessed by pair-wise reading by an independent examiner who was blind regarding the treatment.

RESULTS

The sample comprised 28 (56%) girls and 22 (44%) boys with a defs of 7,3 (SD = 6,5), mainly of moderate (46%) to high (48%) caries risk. Results after one year were published previously. After 2-years, 29 (58%) patients were assessed. Caries progression was observed in 24.1% (7/29) of the test lesions, compared with 55.2% (16/29) of the control lesions (p = 0.012). The therapeutic effect was 31.1% and the relative risk reduction (RRR) was 56.3%. Eigth lesions from the control group and two lesions from the test group progressed to the inner third of dentin and were restored.

CONCLUSIONS

In conclusion, resin infiltration was more efficacious in controlling proximal caries lesions in primary molars than non-invasive approach alone.

CLINICAL SIGNIFICANCE

The results indicate that resin infiltration was an efficacious method in controlling proximal caries lesions in primary molars after 2 years, even in patients with high caries risk, reaffirming the results of 1-year follow-up.

Comparative evaluation of Icon® resin infiltration and Clinpro™ XT varnish on colour and fluorescence changes of white spot lesions: a randomized controlled trial

Background

The aim of this trial was to comparatively evaluate Icon® resin infiltration and Clinpro™ XT varnish in restoring aesthetics of white spot lesions (WSLs) present post-orthodontic treatment.

Materials and methods

Two hundred forty WSLs were detected in 193 teeth of 12 patients. The participants were analysed—before intervention (T₀), immediately after intervention (T₁), 3 months later (T₂) and 6 months later (T₃), with a 1:1 allocation ratio for the application of Icon® resin infiltration and Clinpro™ XT varnish. Using a computer-generated allocation sequence, block randomization was done. A spectrophotometer was used to assess the colour of WSLs and the adjacent enamel, while a DIAGNOdent® was used to assess the fluorescence loss.

Results

Immediately after the intervention, Icon® resin infiltration showed statistically significant better improvement than Clinpro™ XT varnish in restoring the colour (p = 0.000); however, at 3 (p = 0.001) and 6 months (p = 0.000), this was reversed. Except at 3 months, the fluorescence loss sequentially reduced more for Icon® resin infiltration (4.48 ± 1.42 at T₀ to 1.48 ± 0.81 at T₃) and was not statistically significant.

Conclusions

Clinpro™ XT varnish showed significantly better improvement than Icon® resin infiltration in restoring the colour and lightness of the WSLs at 3 and 6 months. The fluorescence loss significantly recovered with both intervention methods between immediate application and at 6 months. However, Clinpro™ XT varnish-treated WSLs showed a statistically significant difference compared to the adjacent sound enamel at 6 months.

Efficacy of Resin Infiltrate in Noncavitated Proximal Carious Lesions: A Systematic Review and Meta-Analysis

Objectives:

Resin infiltration is a minimally invasive technique for treating noncavitated proximal caries. It slows/stops the carious lesion progression rate by creating a diffusion barrier inside the porous enamel lesion body. The aim was to evaluate the efficacy of resin infiltration on noncavitated proximal carious lesions in primary and permanent teeth.

Materials and Methods:

The records were obtained using electronic and other sources. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to ensure transparent reporting. Eligible studies were randomized controlled trials evaluating the efficacy of resin infiltration for noncavitated proximal carious lesions by comparing it with control/placebo. Each included study was assessed concerning the “risk of bias” using the Cochrane Collaboration's “risk-of-bias” assessment tool. High risk-of-bias studies were excluded from the meta-analyses due to selective reporting matters. The statistics were performed by RevMan software (The Cochrane Collaboration, The Nordic Cochrane Centre, Copenhagen, Denmark) utilizing the random effect model. The GRADE approach was implemented for assessing the quality of evidence.

Results:

From 106 studies identified, 17 were assessed for eligibility. After “risk-of-bias” assessment, two meta-analyses were conducted to eliminate the limitation of the significant heterogeneity between trials inspecting primary teeth (n = 2) and permanent teeth (n = 3). I² = 0% indicates the absence of statistical heterogeneity. The risk of carious lesions’ progression with resin infiltration was significantly lower in primary (risk ratio [RR]; 95% confidence interval [CI]: 0.48; 0.30–0.75, P = 0.001) and in permanent teeth (RR; 95% CI: 0.19; 0.11–0.33, P < 0.00001) compared to that of control/placebo. The GRADE approach revealed high quality of evidence.

Conclusion:

The available evidence conveys high confidence that proximal resin infiltration has superior efficacy in slowing/arresting the carious lesions’ progression rate in comparison to conventional management modalities.

Esthetic improvements of postorthodontic white-spot lesions treated with resin infiltration and microabrasion: A split-mouth, randomized clinical trial

OBJECTIVE

To compare the esthetic improvement between postorthodontic white-spot lesions (WSLs) treated by resin infiltration and microabrasion for 12 months.

MATERIALS AND METHODS

A total of 20 patients with 128 teeth with postorthodontic WSLs were recruited. A simple randomized, split-mouth, positive controlled design was used to allocate patients to resin infiltration or microabrasion groups. The lesion area ratio (R value) was calculated between the area of a WSL and the labial surface of the corresponding tooth based on standardized clinical photographs. The color change (ΔE) of each tooth was measured with a Crystaleye spectrophotometer (Olympus, Tokyo, Japan). Every measurement was taken before treatment (T0) and at different time points after treatment: 1 week (T1), 6 months (T6), and 12 months (T12).

RESULTS

A total of 16 patients with 108 trial teeth were available at T12. Each group had 54 trial teeth. In both groups, there was a significant decrease in R value and ΔE between T1 and T0 (P < .0001). In the infiltration group, the R value and ΔE had no significant changes over time from T1 to T12. In the microabrasion group, the R value and ΔE decreased significantly from T1 to T6. The R value of resin infiltration was lower when compared with microabrasion at every recall point (P < .001). The ΔE had no significant differences between the two groups at any timepoint.

CONCLUSIONS

Resin infiltration and microabrasion improved the esthetic appearance of WSLs and showed sufficient durability for 12 months. Resin infiltration showed a better esthetic improvement effect when compared with microabrasion at 12 months.

Effects of different resin sealing therapies on nanoleakage within artificial non-cavitated enamel lesions

The aim of this study was to evaluate nanoleakage within the different lesion-sealing therapies applied to artificial non-cavitated enamel lesions. Thirty-two human anterior teeth were used. Artificial subsurface enamel lesions were produced on the labial surfaces of teeth. The specimens were then randomly divided into three groups (n=10): Group I- Clinpro Sealant application; Group II- ExciTE F adhesive resin application; and Group III- ICON resin infiltrant application. Each group was further divided into two subgroups: control and thermocycler. Nanoleakage was calculated by the digital image analysis software. In the control and thermocycled groups, there was no statistically significant difference between the Groups I, II, and III (p>0.05). The only significant leakage scores were obtained between the Group III control and thermocycler groups (p=0.027). ICON infiltrant can be used as an alternative to dental adhesives and fissure sealants in the sealing of initial non-cavitated enamel lesions. But the resin may become more affected by the water sorption than other resin materials over time. More studies are needed to evaluate long-term durability of resin infiltrants.

Effect of resin infiltration and microabrasion on the microhardness, surface roughness and morphology of incipient carious lesions

OBJECTIVE

The effects of resin infiltration and microabrasion on incipient carious lesions by surface microhardness, roughness and morphological assessments, and resistance to further acid attack of treated lesions were evaluated.

MATERIAL AND METHODS

Eighty artificially-induced incipient lesions were randomly divided into five groups (n = 16): resin infiltration with an adhesive resin (Excite F, Ivoclar Vivadent, Schaan, Liechtenstein), resin infiltration with a resin infiltrant (Icon, DMG, Hamburg, Germany), microabrasion without polishing (Opalustre, Ultradent, South Jordan, UT, USA), microabrasion with polishing (Opalustre, Ultradent, Diamond Excel, FGM, Joinville, SC, Brazil), and distilled water (control group). All specimens were exposed to demineralization for another 10 d. Microhardness, roughness and morphological assessments were done at baseline, following initial demineralization, treatment and further demineralization. Data were analysed by the Kruskal-Wallis, Friedman's and Bonferroni tests (p < .05).

RESULTS

Enamel lesions treated with resin infiltrant and microabrasion demonstrated similar hardness values, with a nonsignificant difference compared with sound enamel. Resin infiltration demonstrated lower roughness values than those of microabrasion, and the values did not reach the values of sound enamel. Further demineralization for 10 d did not affect the hardness but increased the roughness of infiltrated and microabraded enamel surfaces. Polishing did not influence the roughness of microabraded enamel surfaces. After resin infiltration, porosities on enamel were sealed completely. The surface structure was similar to that of the enamel conditioning pattern for microabraded enamel lesions.

CONCLUSIONS

Within the limitations of this study, the icon infiltration and microabrasion technique appeared to be effective for improving microhardness. Icon appeared to provide reduced roughness, although not equal to sound enamel. Further research is needed to elucidate their clinical relevance.

Effect of Resin Infiltration on Artificial Caries: An in vitro Evaluation of Resin Penetration and Microhardness

Aim

To evaluate the effectiveness of resin infiltration on artificial caries lesion by assessing the depth of resin penetration and the change in microhardness of lesion postinfiltration.

Materials and methods

Totally 45 human extracted premolars were used to create an artificial demineralized lesion in enamel using demineralizing solution. A total of 15 samples (group I) were infiltrated with resin. The depth of resin penetration was studied using scanning electron microscope (SEM). Other half (n = 30) of samples was equally divided into three subgroups and Vickers hardness number (VHN) values were obtained to measure the surface microhardness as group 11 a—before demineralization, 11 b—after demineralization, IIc—postresin infiltration.

Results

Mean depth of penetration in group I was 516.8 urn. There was statistically significant increase in VHN values of demineralized lesion postresin infiltration (independent Student’s t-test, p < 0.001).

Conclusion

Penetration depth of the resin infiltrant was deep enough to render beneficial effects, while significant increase in microhardness was observed postresin infiltration.

Clinical significance

Infiltrant used can be considered as a valid treatment option for noncavitated lesions.

How to cite this article

Prajapati D, Nayak R, Pai D, Upadhya N, Bhaskar VK, Kamath P. Effect of Resin Infiltration on Artificial Caries: An in vitro Evaluation of Resin Penetration and Microhardness. Int J Clin Pediatr Dent 2017;10(3):250-256.

Efficacy of resin infiltration of proximal caries in primary molars: 1-year follow-up of a split-mouth randomized controlled clinical trial

OBJECTIVE

The main purpose of this split month, randomized, controlled clinical trial was evaluate the efficacy of caries infiltration in controlling the progression of non-cavitated proximal lesions in primary molars. Anxiety and time required for the caries infiltration was also evaluated.

MATERIALS AND METHODS

Fifty healthy children, 5 to 9 years, presenting two primary molars with proximal caries lesions (1/2 of the enamel or outer 1/3 of dentin), were included. Lesions were randomly allocated to the test group (fluoridated toothpaste + flossing + infiltration) or to the control group (fluoridated toothpaste + flossing). Caries risk was based on the Cariogram model. The main outcome after 1-year radiographic follow up was assessed by an independent blinded examiner A facial image scale (FIS) was applied to assess dental anxiety and time required to perform the infiltration was recorded.

RESULTS

Of the sample, 92.9% corresponded to high or medium caries risk. In 42 patients (1-year follow up), caries progression was observed in 11.9% (5/42) of the test lesions compared with 33.3% (14/42) of the control lesions (p < 0.05). Five control and three test lesions progressed to the middle 1/3 of dentin and were restored. No side effects were observed. Anxiety was both low before and after the treatment, and mean time required for the infiltration was 11.29 min (± 1.16 min).

CONCLUSIONS

Caries infiltration of proximal caries lesions in primary molars is significantly more efficacious than standard therapy alone (fluoride toothpaste + flossing).

CLINICAL RELEVANCE

Caries infiltration is an applicable and well-accepted method be used in children, representing a promising micro-invasive approach.

Caries progression in non-cavitated fissures after infiltrant application: a 3-year follow-up of a randomized controlled clinical trial

Objectives

To evaluate the efficacy of a conservative treatment to prevent the progression of caries using an infiltrant on non-cavitated pit and fissures.

Material and Methods

This controlled clinical trial selected 23 volunteers with clinically and radiographically non-cavitated occlusal caries among patients presenting a “rather low” to “very high” caries risk. Eighty-six teeth were randomly divided into two experimental groups: teeth receiving a commercial pit-and-fissure sealant (Alpha Seal-DFL) and contralateral teeth receiving Icon infiltrant (DMG). Caries progression was monitored by clinical (laser fluorescence caries detection) and radiographic examination at 12-month intervals over a period of 3 years of monitored caries progression. Probing the sealing materials to detect areas of retention was also used to evaluate marginal integrity.

Results

Statistical analysis showed no difference in caries progression using laser fluorescence caries detection when both materials were compared, regardless of the evaluation times (p>0.05). No significance was observed when the marginal sealant integrity of both materials was compared, regardless of the evaluation time (p<0.05). Marginal integrity significantly reduced after 1 year for both materials (p<0.05), but remained stable after 2 and 3 years of evaluation, compared with 1-year results (p>0.05). SEM analysis exhibited a more homogeneous sealing for the infiltrant than obtained by the sealant.

Conclusions

The infiltrant was effective to prevent the caries progression in non-cavitated pit-and-fissures after 3 years of clinical evaluation, comparable with the conventional sealant. The infiltrant also presented better results in terms of caries progression at the 3-year evaluation time using the radiographic analysis.

Comparative study of two chemical protocols for creating white spot lesions: An in vitro FluoreCam evaluation

AIM

The aim of the present study was to compare the effectiveness and practicality of two commonly-used protocols for white spot lesion creation.

METHODS

Sound posterior human teeth were sectioned into halves and randomly allocated into two groups (n=20). Using the FluoreCam system, the enamel surfaces were imaged under standardized conditions, and baseline data (area, intensity, and impact) were recorded. Specimens were covered with an acid-resistant polish, leaving a 2×6-mm enamel window. Group 1 was immersed in Queiroz solution (64 hours/37°C/pH5 with agitation); Group 2 was immersed in Buskes solution (14 days/37°C/pH5 with agitation). The specimens then were imaged again. Within-group changes that occurred over time were evaluated using the Wilcoxon signed-rank test. Between-group differences were analyzed using the Mann-Whitney U-test. Polarized light microscopy (PLM) was used to calculate the mean lesion depth of representative specimens.

RESULTS

Each protocol showed significant changes in the surface area, intensity and impact of demineralization over time (P<.05). There were no statistically-significant differences (P=.53, P=.2, P=.74) between the two groups. PLM showed that the mean lesion depths of representative specimens were 51.4 and 73.0 μm for groups 1 and 2, respectively.

CONCLUSIONS

While both protocols produce similar amounts of demineralization, the Queiroz solution is more practical, as it requires less time.

Surface Roughness of Initial Enamel Caries Lesions in Human Teeth After Resin Infiltration

BACKGROUND

Low viscosity resin infiltration of initial caries lesions is a modern microinvasive method to treat initial cries lesions. However, only scarce information is available about the long-term surface alterations of infiltrated lesions.

METHODS

Twenty-eight premolar teeth exhibiting non-cavitated initial caries lesions (International Caries Detection and Assessment System (ICDAS code 1&2)) were divided into two groups, one of which was infiltrated with resin, and the other remained untreated. The teeth underwent two thermocycling procedures. The surface roughness was determined quantitatively, and the results were evaluated statistically. In addition, the surfaces of the lesions were investigated by scanning electron microscopy (SEM), and the surface was analyzed visually with respect to surface irregularities.

RESULTS

The results showed a reduction in the surface roughness that was significant after 2500 thermocycles compared to the untreated surface. In the control specimens, no change in the surface roughness was found. The qualitative SEM data also showed a smooth surface after thermocycling, which supported the statistical findings.

CONCLUSION

After thermocycling, resin-infiltrated enamel surfaces become smoother and had no additional risk for plaque accumulation.

Surface Properties and Color Stability of Resin-Infiltrated Enamel Lesions

OBJECTIVES

To examine the surface topographies, microhardness, and color stability of resin-infiltrated enamel lesions before and after aging challenges in vitro using three-dimensional laser scanning profilometry, surface microhardness testing, spectrophotometry, and scanning electron microscopy.

METHODS

Forty human third molars were embedded in epoxy resin, and each tooth was prepared to have two white spot lesions and one sound enamel area. One white spot lesion received resin infiltration and the other was untreated. Ten specimens were subjected to thermocycling for 10,000 cycles, 10 specimens were immersed in coffee solutions, and 10 specimens were placed in water storage. Surface area roughness (Sa), Vickers microhardness (VHN), and CIE L*a*b* color values were measured on sound enamel, resin-infiltrated lesions, and untreated lesions before and after aging. The surface morphology of resin-infiltrated lesions was observed after aging under scanning electron microscopy and compared with 10 specimens that were not subjected to aging challenge.

RESULTS

Resin infiltration increased the surface microhardness of the enamel lesions from 89.3 to 212.0 VHN. The surface microhardness of resin-infiltrated enamel lesions was not significantly affected by aging. The surface roughness of resin-infiltrated lesions (0.32-0.37 μm) was greater than that of sound enamel (0.05-0.06 μm) and untreated lesions (0.12-0.13 μm). Thermocycling and water storage further increased surface roughness of resin-infiltrated surfaces. Resin-infiltrated enamel lesions showed greater discoloration than sound enamel surfaces. Surface microfissures and microcracks were observed on resin-infiltrated enamel lesions after thermocycling.

CONCLUSIONS

Surface hardness of enamel lesions increased significantly after resin infiltration and remained stable following thermocycling. Surface roughness and color stability of resin-infiltrated enamel lesions were less than ideal and might further deteriorate after aging in the oral environment.

Evaluation of resin infiltration using quantitative light-induced fluorescence technology

OBJECTIVES

To determine whether quantitative light-induced fluorescence (QLF) technology can be used to classify the colour of teeth specimens before and after resin infiltration (RI) treatment, and calculate the correlation between the ΔF value and colour difference (ΔE) in fluorescence images of the specimens obtained using a QLF-digital (QLF-D) device.

METHODS

Sixty sound bovine permanent teeth specimens were immersed in demineralized solution. Two exposed windows were formed in each specimen, and RI treatment was applied to one of them. The ΔE values were obtained for the differences between a sound tooth surface (SS), an early dental caries surface (ECS) and an ECS treated with RI (RS) in white-light and fluorescence images obtained using QLF-D, respectively. The ΔF value was obtained from fluorescence images using dedicated software for QLF-D. The mean differences between the ΔE values obtained from the white-light and fluorescence images were analyzed by paired t-test. Pearson correlation analysis and Bland-Altman plots were applied to the differences between the ΔF value for ECS (ΔFSS-ECS) and the ΔE value between SS and ECS (ΔESS-ECS), and between the ΔF value for RS (ΔFSS-RS) and the ΔE value between SS and RS (ΔESS-RS) in fluorescence images.

RESULTS

The ΔE values obtained from fluorescence images were three times higher than the ΔE values obtained from white-light images (p<0.001). Significant correlations were confirmed between ΔESS-ECS and ΔFSS-ECS (r=-0.492, p<0.001) and between ΔESS-RS and ΔFSS-RS (r=-0.661, p<0.001).

CONCLUSION

QLF technology can be used to confirm the presence of RI in teeth.

Caries-preventive effect of anti-erosive and nano-hydroxyapatite-containing toothpastes in vitro

OBJECTIVES

The aim of the study was to investigate the caries-preventive effect of newly developed fluoride and fluoride-free toothpastes specially designed for erosion prevention. The hypothesis was that these products might also show superior caries-inhibiting effect than regular fluoride toothpastes, since they were designed for stronger erosive acid challenges.

MATERIALS AND METHODS

Enamel specimens were obtained from bovine teeth and pre-demineralized (pH = 4.95/21 days) to create artificial caries lesions. Baseline mineral loss (ΔZ_B) and lesion depth (LD_B) were determined using transversal microradiography (TMR). Ninety specimens with a median ΔZ_B (SD) of 6027 ± 1546 vol% × μm were selected and randomly allocated to five groups (n = 18). Treatments during pH-cycling (14 days, 4 × 60 min demineralization/day) were brushing 2×/day with AmF (1400 ppm F^-, anti-caries [AC]); AmF/NaF/SnCl₂/Chitosan (700 ppm F^-/700 ppm F^-/3500 ppm Sn²⁺, anti-erosion [AE1]); NaF/KNO₃ (1400 ppm F^-, anti-erosion [AE2]); nano-hydroxyapatite-containing (0 ppm F^-, [nHA]); and fluoride-free toothpastes (0 ppm F^-, negative control [NC]). Toothpaste slurries were prepared with mineral salt solution (1:3 wt/wt). After pH-cycling specimens presenting lesion, surface loss (mainly by NC and nHA) were discarded. For the remaining 77 specimens, new TMR analyses (ΔZ_E/LD_E) were performed. Changes in mineral loss (ΔΔZ = ΔZ_B - ΔZ_E) and lesion depth (ΔLD = LD_B - LD_E) were calculated.

RESULTS

All toothpastes caused significantly less demineralization (lower ΔΔZ) than NC (p < 0.05, ANOVA) except for nHA. The fluoride toothpastes did not differ significantly regarding ΔΔZ and ΔLD (p > 0.05, ANOVA).

CONCLUSION/CLINICAL RELEVANCE

While both anti-erosive and anti-caries toothpastes reduced mineral loss to a similar extent, the fluoride-free nano-hydroxyapatite-containing toothpaste seemed not to be suitable for inhibition of caries demineralization in vitro.

Evaluation of Stain Penetration by Beverages in Demineralized Enamel Treated With Resin Infiltration

PURPOSE

To evaluate stain penetration by different beverages in artificially demineralized human teeth treated with resin infiltration.

METHODS AND MATERIALS

Sixty extracted human permanent molars were demineralized, treated with resin infiltration (Icon), and immersed in four different beverages (coffee, grape juice, iced tea, and distilled water; N=15) for four weeks. After aging, teeth in the distilled water group were stained with 2% methylene blue for 24 hours. All teeth were sectioned, and stain penetration was evaluated under light microscopy. Chi-square test, independent and paired sample t-test, analysis of variance with the Fisher least significant difference post hoc test, and the Kruskal-Wallis test were used to analyze the results (p<0.05).

RESULTS

Resin infiltration-treated surfaces (Icon surfaces) had statistically significant fewer samples with presence of stain penetration compared to untreated surfaces (control surfaces) (p<0.001). There was also a significant decrease in depth of stain penetration in Icon surfaces compared to the control surfaces (p<0.001). Among tested beverage groups, iced tea showed significantly greater depth of stain penetration (0.134±0.029 mm), followed by grape juice (0.118±0.047 mm), methylene blue (0.022±0.019 mm), and coffee (0.008±0.017 mm; p<0.001).

CONCLUSION

Both Icon and control surfaces exhibit stain penetration by different beverages (iced tea, grape juice, and coffee). However, resin-infiltrated enamel surfaces allow significantly less depth of stain penetration compared to untreated surfaces. The iced tea group presents greatest depth of stain penetration, followed by grape juice, methylene blue, and coffee.

Micro-computed tomographic analysis of progression of artificial enamel lesions in primary and permanent teeth after resin infiltration

We investigated inhibition of lesion progression in artificial enamel lesions. Lesions were created on primary and permanent anterior teeth (n = 10 each) and were divided randomly into two groups with two windows: Group 1 (window A: resin infiltration; window B: negative control) and Group 2 (window A: resin infiltration + fluoride varnish; window B: fluoride varnish). After pH cycling, micro-computed tomography was used to analyze progression of lesion depth and changes in mineral density. Resin infiltration and resin infiltration + fluoride varnish significantly inhibited progression of lesion depth in primary teeth (P < 0.05). Inhibition of lesion depth progression in permanent teeth was significantly greater after treatment with resin infiltration + fluoride varnish than in the negative control (P < 0.05). Change in mineral density was smaller in the resin infiltration and resin infiltration + fluoride varnish groups; however, the difference was not significant for either group (P > 0.05). Resin infiltration is a promising method of inhibiting progression of caries lesions.

Attempt to assess the infiltration of enamel made with experimental preparation using a scanning electron microscope

INTRODUCTION

The resin infiltration technique, a minimally invasive method, involves the saturation, strengthening, and stabilization of demineralized enamel by a mixture of polymer resins without the need to use rotary tools or the risk of losing healthy tooth structures.

AIM OF THE STUDY

To design and synthesize an experimental infiltrant with potential bacteriostatic properties.To compare the depth of infiltration of the designed experimental preparation with the infiltrant available in the market using a scanning electron microscope.

MATERIAL AND METHODS

Composition of the experimental infiltrant was established after analysis of 1H NMR spectra of the commercially available compounds that can penetrate pores of demineralized enamel. As the infiltrant should have bacteriostatic features by definition, an addition of 1% of monomer containing metronidazole was made. Thirty extracted human teeth were soaked in an acidic solution, which was to provide appropriate conditions for demineralization of enamel. Afterward, each tooth was divided along the coronal-root axis into two zones. One zone had experimental preparation applied to it (the test group), while the other had commercially available Icon (the control group). The teeth were dissected along the long axis and described above underwent initial observation with use of a Hitachi S-4200 scanning electron microscope.

RESULTS

It was found that all samples contained only oxygen and carbon, regardless of the concentration of additions introduced into them. The occurrence of carbon is partially because it is a component of the preparation in question and partially because of sputtering of the sample with it. Hydrogen is also a component of the preparation, as a result of its phase composition; however, it cannot be detected by the EDS method.

CONCLUSIONS

SEM, in combination with X-ray microanalysis, does not allow one to explicitly assess the depth of penetration of infiltration preparations into enamel.In order to assess the depth of penetration of infiltration preparations with use of X-ray microanalysis, it is recommended to introduce a contrast agent that is approved for use in dental materials, such as ytterbium III fluoride.

Effect of resin infiltration on the nanomechanical properties of demineralized bovine enamel

Objective:

The aim of the present study was to evaluate the efficacy of resin infiltration in preventing in vitro lesion progression.

Materials and Methods:

Buccal surfaces of bovine incisors were divided into mesial and distal regions and, at the center, nail varnish was applied (1.0 mm width) to protect the enamel surface against any further treatment. In order to create artificial enamel lesions in the unprotected areas, each specimen was soaked in a demineralizing solution. After that, specimens had two enamel lesions. One lesion in each sample was etched with 15% HCl for 120 s and infiltrated with a commercial infiltrating resin for 3 min, while the other lesion was not treated (control). Each specimen was cross-sectionally halved and randomly allocated to two groups: Group 1 was immediately processed and Group 2 was submitted to a new demineralization process. The samples were analyzed by means of cross-sectional hardness measurements using a nanoindenter equipment. Hardness data were statistically analyzed by non-parametric Kruskal-Wallis and MannWhitney tests (α = 0.05).

Results:

The findings showed statistical difference between treatments at the same analyzed distance range from the outer surface of the enamel (P < 0.05).

Conclusion:

The untreated lesion showed lower hardness values for distances near the outer surface of the enamel. The resin infiltration was efficient in preventing further in vitro demineralization of bovine enamel lesions.

Effectiveness of an infiltrant on sealing of composite restoration margins with/without artificial caries

AIM

The aim of this in vitro study was to evaluate the effectiveness of a resin infiltrant (ICON) on marginal sealing ability of class II resin restorations with/without-caries.

MATERIALS AND METHODS

Forty-eight noncarious human pre-molar teeth were embedded and MO and DO preparations of standard dimensions were prepared. The left side of dentin margins of the cavities were left nonbonded (UB) while the right side were bonded using total etch-bonding agent and all restored with a Nanohybrid composite. The teeth were thermocycled and half of the specimens in the UB and B groups were subjected to an artificial caries process. ICON was applied to caries and noncaries subgroups following the manufacturer's directions. Impressions were made at each step: after the restorations were completed, thermocycling, artificial caries procedures, and infiltrant application and the silicone tag lengths were measured with a stereomicroscope. The specimens were immersed in 0.5% basic fuchsine at 37° C for 24 hours, sectioned and microleakage was evaluated with a stereomicroscope. Selected samples and their replicas were assessed for marginal quality under a stereomicroscope and SEM. Statistical evaluation of the data were made using Kruskal-Wallis, Mann-Whitney U and Wilcoxon Sign Rank tests.

RESULTS

While bonding application did not create a meaningful difference, the thermocycling and artificial caries significantly increased the gap length and microleakage (p < 0.05). ICON application was decreased the microleakage, created gap-free margins and closed the gaps which were previously occurred at the same cavities (p < 0.05).

CONCLUSION

A resin infiltrant (ICON) application decreased the microleakage, created gap-free margins and closed the gaps, which previously occurred at the same cavities.

CLINICAL SIGNIFICANCE

Approximal application of resin infiltrant may increase the success of the class II composite restorations also reduced the risk of needing more complex restoration therapy.

In Vitro Progression of Artificial White Spot Lesions Sealed With an Infiltrant Resin

This study assessed the ability of an infiltrant resin (Icon, DMG Chemisch-Pharmazeutische Fabrik GmbH, Hamburg, Germany) to prevent artificial lesion progression in vitro when used to impregnate white spot lesions and also assessed the effect of saliva contamination on resin infiltration. Enamel specimens (n=252) were prepared and covered with nail varnish, leaving a window of sound enamel. After demineralization (pH 5.0; four weeks), specimens were divided into six groups (n=42 per group): group 1, 2% fluoride gel (positive control); group 2, resin infiltrant; group 3, resin infiltrant + fluoride gel; group 4, no treatment (negative control); group 5, resin infiltrant application after saliva contamination; and group 6, resin infiltrant + fluoride gel after saliva contamination. Specimens from each group were cut perpendicular to the surface, and one-half of each specimen was exposed to a demineralizing solution for another four weeks. The other half was set aside as a record of initial lesion depth and was used later in the determination of lesion progression. Lesion progression and infiltrant penetration were measured using confocal laser scanning microscopy (CLSM) and transverse microradiography (TMR). For lesion depth, based on CLSM, groups 2 and 3 showed the least changes when submitted to demineralization challenge, followed by group 1, then groups 5 and 6, and finally group 4. There were no significant differences between groups 2 and 3 or groups 5 and 6 in their ability to inhibit further lesion progression (p&lt;0.05). Based on TMR, groups 2 and 3 also showed the fewest changes when submitted to demineralization challenge, followed by group 5, then groups 1 and 6, and finally group 4. In terms of mineral loss as measured by TMR, all groups that contained fluoride (groups 1, 3, and 6) show less percentage change in mineral loss than the groups that did not contain fluoride (groups 2, 4, and 5). It can be concluded that infiltrant penetration into early enamel lesions inhibited further demineralization in vitro, especially in the presence of fluoride. Saliva contamination decreased the ability of the infiltrant to prevent further demineralization, but the presence of fluoride seemed to counteract this effect.

Modification of surface pretreatment of white spot lesions to improve the safety and efficacy of resin infiltration

Objective

A low-viscosity resin (infiltrant) was used to inhibit the progression of white spot lesions (WSLs) and resolve associated esthetic issues. An alternative pretreatment was explored to increase the pore volume of the surface layer of the WSLs. Also, the penetration effects of the infiltrant were evaluated for various pretreatments.

Methods

Sixty two artificial lesions were fabricated on bovine teeth. As a positive control, 15% HCl gel was applied for 120 seconds. Further, 37% H₃PO₄ gel was applied for 30 seconds using three methods. The samples were divided as follows: H₃PO₄ only group, H₃PO₄ sponge group, and H₃PO₄ brush group. The acid was gently rubbed with the applicators (i.e., a sponge or brush) throughout the application time. To compare the effects of resin infiltration, twenty paired halves of specimens were treated with an infiltrant (ICON®).

Results

Thicknesses of the removed surface layers and infiltrated areas were evaluated by confocal laser scanning microscope. The positive control and the 37% H₃PO₄ brush group failed to show significant differences in the removed thickness (p > 0.05); however, the mean percentage of the infiltrated area was higher in the 37% H₃PO₄ brush group (84.13 ± 7.58%) than the positive control (63.51 ± 7.62%, p < 0.001). Scanning electron microscope observations indicate higher pore volumes for the 37% H₃PO₄ brush group than for the positive control.

Conclusions

Application of 37% H₃PO₄ with a brush for 30 seconds increased the pore volume of WSL surface layers and the percentage of infiltrated areas in comparison to the use of 15% HCl for 120 seconds.

Is non-cavitated proximal lesion sealing an effective method for caries control in primary and permanent teeth? A systematic review and meta-analysis

OBJECTIVES

The aim of this study was to perform a systematic review and meta-analysis on the effectiveness of sealing non-cavitated proximal caries lesions in primary and permanent teeth.

DATA

Only controlled clinical trials and randomized controlled clinical trials that evaluated the effectiveness of sealing on non-cavitated proximal caries with a minimum follow-up of 12 months were included in the study. The primary outcome should be arrestment/progression of proximal caries evaluated by bitewing radiographs. A risk of bias evaluation based on the Cochrane Collaboration common scheme for bias was carried out for each study. The meta-analysis was performed on the studies considered low risk of bias and with pair-wise visual reading results through RevMan software.

SOURCES

A comprehensive search was performed in the Systematic Electronic Databases: Pubmed, Cochrane Library, Scopus, IBI Web of Science, Lilacs, SIGLE, and on website Clinical trials.gov, through until June 2013.

STUDY SELECTION

From 967 studies identified, 10 articles and 3 studies with partial results were assessed for eligibility. However three articles were excluded and our final sample included 10 studies. According to the risk of bias evaluation, six studies were considered "high" risk of bias, and four "low" risk of bias. The forest plot of the meta-analysis showed low heterogeneity (I(2)=29%) and a favourable outcome for the Infiltrant. The chance of caries progression when this technique was used was significantly lower (p=0.002) compared with Placebo.

CONCLUSION

Our results suggest that the technique of sealing non-cavitated proximal caries seems to be effective in controlling proximal caries in the short and medium term. Further long-term randomized clinical trials are still necessary to increase this evidence.

CLINICAL SIGNIFICANCE

Contemporary dentistry is focused in minimally invasive approaches that prevent the destruction of sound dental tissues next to carious lesions. This paper searches for evidence of the efficacy of sealing/infiltrating non-cavitated proximal caries in arresting caries progression both in permanent and primary teeth.