Evaluation of the masking efficacy of caries infiltration in post-orthodontic initial caries lesions: 1-year follow-up.

OBJECTIVES: This study aimed to qualitatively and quantitatively assess the masking efficacy and color stability of resin infiltration on post-orthodontic ICL after 1 year. MATERIALS AND METHODS: In 17 adolescents, 112 ICL (ICDAS-1: n = 1; ICDAS-2: n = 111) in 112 teeth were treated by resin infiltration (Icon, DMG) 3 to 12 months after bracket removal. The etching procedure was performed up to 3 times. Standardized digital images were taken before treatment (T0), 7 days (T7) and 12 months (T365) after treatment. Outcomes included the evaluation of the color differences between infiltrated and healthy enamel at T0, T7, and T365 by quantitative (colorimetric analysis (ΔE), ICDAS scores) and qualitative methods (5-point Likert scale (deteriorated (1), unchanged (2), improved, but not satisfying (3), improved and no further treatment required (4), completely masked (5)).) Differences between time points were analyzed by using Friedman test (ΔΕ) and chi-square tests (ICDAS). RESULTS: The median color difference (25th/75th percentiles) between carious and healthy enamel at baseline (ΔΕ0) was 10.2(7.7/13.6). A significant decrease was observed 7 days after treatment (ΔΕ7 = 3.1(1.8/5.0); p < 0.001; ICDAS; p < 0.001). No significant changes based on ΔΕ (p = 1.000), and ICDAS grade (p = 0.305) were observed between T7 and T365 (ΔΕ12 = 3.4 (1.8/4.9)). Furthermore, at T365 four experienced dentists classified 55% and 39% of the lesions as "improved and no further treatment required" and "completely masked," respectively (Fleiss kappa: T365 = 0.851 (almost perfect)). CONCLUSION: Resin infiltration efficaciously masked post-orthodontic ICL 7 days and 12 months after treatment. These results for most of the teeth could not only be observed by quantitative but also by qualitative analysis. CLINICAL RELEVANCE: Resin infiltration efficaciously masks post-orthodontic initial carious lesions. The optical improvement can be observed directly after treatment and remains stable for at least 12 months.

Improved Surface Layer Erosion of Pit and Fissure Caries Lesions in Preparation for Resin Infiltration.

The penetration of a low-viscosity resin (infiltrant) into caries lesions depends on the erosion of the relatively impermeable surface layer (SL) that covers the lesion body. The present study aimed to evaluate the effect of different abrasive pretreatments on erosion of the SL and on penetration of an infiltrant into occlusal caries lesions, simultaneously. Sixty extracted human molars showing International Caries Detection and Assessment System (ICDAS-2) lesions were randomly allocated to 5 groups. A small area of each lesion was covered with resin before etching. Twelve lesions each were etched with either 15% HCl-gel (H120) or 37% H3PO4-gel (P120) for 120 s. Furthermore, the standard 15% HCl-gel or either one of two experimental etchants (HCl-gel or H3PO4-gel, each including abrasives) were applied for either 120 s or 30 s using a brush (surface pressure 150 g) (H30B, P120BA, H30BA). After rinsing and drying, all lesions were infiltrated for 180 s (Icon; DMG). From each tooth sections were prepared and visualized using confocal microscopy. SL of unetched areas and the lesion depth were 33 (23/51) µm and 537 (274/876) µm, respectively, both not differing significantly between groups. H120, H30B, and H30BA showed significantly higher SL reduction compared with P120 or P120BA, but only for H30BA SL was eroded almost completely (p < 0.05; Mann-Whitney test). Compared to other groups, occlusal lesions were significantly more infiltrated in H30BA (p < 0.05; Mann-Whitney test). HCl-gel including abrasives that was rubbed onto the enamel surface with a brush seems to be most effective to erode SLs of caries lesion situated in fissures and enable an almost complete subsequent resin infiltration.

Do bleaching gels affect the stability of the masking and caries-arresting effects of caries infiltration-in vitro.

OBJECTIVES: The aim of this study was to evaluate the influence of different bleaching gels on the masking and caries-arresting effects of infiltrated and non-infiltrated stained artificial enamel caries lesions. MATERIALS AND METHODS: Bovine enamel specimens (n = 240) with each two sound areas (SI and SC) and each two lesions (DI and DC) were infiltrated (DI and SI), stained (1:1 red wine-coffee mixture,70 days), and randomly distributed in six groups to be bleached with the following materials: 6%HP (HP-6), 16%CP (CP-16), 35%HP (HP-35), 40%HP (HP-40), and no bleaching (NBl,NBl-NBr). Subsequently, specimens were pH-cycled (28 days, 6 × 60 min demineralization/day) and all groups except NBl-NBr were brushed with toothpaste slurry (1.100 ppm, 2×/day, 10 s). Differences in colorimetric values (ΔL, ΔE) and integrated mineral loss (ΔΔZ) between baseline, infiltration, staining, bleaching, and pH cycling were calculated using photographic and transversal microradiographic images. RESULTS: At baseline, significant visible color differences between DI and SC were observed (ΔEbaseline = 12.2; p < 0.001; ANCOVA). After infiltration, these differences decreased significantly (ΔEinfiltration = 3.8; p < 0.001). Staining decreased and bleaching increased ΔL values significantly (p ≤ 0.001). No significant difference in ΔΔE was observed between before staining and after bleaching (ΔEbleaching = 4.3; p = 0.308) and between the bleaching agents (p = 1.000; ANCOVA). pH-cycling did not affect colorimetric values (ΔEpH-cycling = 4.0; p = 1.000). For DI, no significant change in ΔZ during in vitro period was observed (p ≥ 0.063; paired t test). CONCLUSIONS: Under the conditions chosen, the tested materials could satisfactorily bleach infiltrated and non-infiltrated stained enamel. Furthermore, bleaching did not affect the caries-arresting effect of the infiltration. CLINICAL RELEVANCE: The present study indicates that bleaching is a viable way to satisfactorily recover the appearance of discolored sound enamel and infiltrated lesions.

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.

Effects of Self-Assembling Peptide P11-4, Fluorides, and Caries Infiltration on Artificial Enamel Caries Lesions in vitro.

The application of a self-assembling peptide on noncavitated caries lesions is supposed to be a feasible approach to facilitate remineralization and mask their unfavorable appearance. However, demineralizing conditions are common in the oral environment, so the aim of this pH-cycling study was to compare recommended and novel treatment methods regarding their ability to hamper demineralization and as a consequence mask artificial enamel caries lesions. Artificial caries lesions were prepared in bovine enamel and randomly allocated to 11 groups (n = 22). Treatments before pH-cycling were as follows: the application of a self-assembling peptide (Curodont™ Repair [C]), a low-viscosity resin (Icon® [I]), 2 fluoride solutions (10,000 ppm F-: Elmex fluid [E] and 43,350 ppm F-: Tiefenfluorid® [T]), and no intervention (N). During pH-cycling (28 days, 6 × 60 min demineralization/day) half of the specimens in each group were brushed (10 s; 2 ×/day) with either fluoride-free (named e.g., C0) or NaF (1,100 ppm F-; e.g., C1) dentifrice slurry. In another subgroup specimens were pH-cycled but not brushed (NNB). Differences in integrated mineral loss (ΔΔZ), lesion depth (ΔLD), and colorimetric values (ΔΔE) were calculated between values after pre-demineralization, surface treatment, and pH-cycling. Specimens of C0, C1, NNB, N0, N1, T0, and E0 showed significantly increased ΔZ and LD values after pH-cycling (p ≤ 0.003; paired t test). C0, C1, NNB, and N0 showed significantly higher changes in ΔΔZ than E1, I0, I1, and T1 (p < 0.001; ANOVA). Significantly reduced colorimetric values could only be observed for I1, I0, E1, and E0 after treatment and after pH-cycling (p ≤ 0.027; paired t test). In conclusion, under the conditions chosen only the application of a low-viscosity resin could mask caries lesions significantly, whereas self-assembling peptides could neither inhibit lesion progression nor mask the lesions considerably.

Multiple censored data in dentistry: A new statistical model for analyzing lesion size in randomized controlled trials.

Caries infiltration is a novel treatment option for proximal caries lesions. The idea is to build a diffusion barrier inside the lesion to slow down or stop the caries progression. If a lesion still reaches a critical size, restorative treatment is required. Clinical trials investigating caries infiltration thus produce multiple censored ordinal data. Standard statistical models do not take into account this censoring, and we therefore propose the Multiple Ordered Tobit (MOT) model. The model is implemented in R and compared with standard approaches. Simulation studies demonstrate that for all sample sizes and scenarios the MOT model has the largest statistical power among all methods compared, and it is robust against heteroscedasticity to some extent. Finally, a comparison with dichotomous and ordinal scaled models shows that the use of metric data for the lesion size reduces the required sample size considerably.

Influence of resin infiltration pretreatment on the microleakage under orthodontic bracket (an in vitro study).

OBJECTIVES: In order to assess the changes in tooth orthodontic adhesive interface microleakage after applying a caries resin penetrated to the sound enamel tooth surface in different storage media. MATERIALS AND METHODS: A total of 60 human maxillary first premolars (orthodontic extraction) were collected by random separation of the teeth into two equal groups. The control group was classified into three subgroups (n = 10) (control in deionized water, control in milk, and control in energy drink), while the experimental one (treated with ICON) was categorized into three subgroups (n = 10) (ICON in deionized water, ICON in milk, and ICON in energy drink) incubation phase lasted three weeks in total. RESULTS: A one-way analysis of variance (ANOVA) yielded a significant difference between all experimental subgroups (ICON in deionized water, ICON in milk, and ICON in energy drink) and control subgroups (control in deionized water, control in milk, and control in energy drink). The control group in the energy drink subgroup had the highest mean microleakage value when compared to the other subgroups, whereas the resin-infiltrated group in deionized water had the lowest mean value. According to the results of the T-test, ICON pre-treatment tooth samples had significantly lower mean values of microleakage than non-ICON tooth samples. CONCLUSIONS: The adhesive system (control group) revealed that a resin infiltrate on a sound enamel surface prior to orthodontic bracket bonding reduced bracket tooth interface microleakage in all examined samples. The ICON-infiltrated surface was discovered to provide a secondary preventive strategy against white spot lesion development by reducing microleakage under brackets.

Masking-efficacy and caries arrestment after resin infiltration or fluoridation of initial caries lesions in adolescents during orthodontic treatment-A randomised controlled trial.

OBJECTIVES: The aim of this randomised, controlled, split-mouth trial was to assess the masking results in initial caries lesions (ICL) that were either resin infiltrated or fluoridated during treatment with fixed orthodontic appliances. METHODS: Adolescent patients (age range:12-18years) with fixed orthodontic appliances who had developed ICL [ICDAS 1 or 2 (International Caries Detection and Assessment System)] during orthodontic treatment were consecutively recruited and randomly assigned to either resin infiltration with up to 3 etching procedures (Group:Inf) or to 3-monthly application of a fluoride varnish (Group:FV). Both interventions were performed according to the manufacturer's recommendations. Primary and secondary outcomes (ΔE, ICDAS, DIAGNOdent) included the evaluation of the appearance of the ICL before (T0), 1 week after (T1) treatment and at the last appointment before debonding (T2). RESULTS: Fifteen patients (8females, 7males) with 57ICL were included. Mean (SD) observation time at the last appointment before debonding was 0.5 (0.3) years. At T0 FV and Inf did not differ significantly in ΔE (median ΔE0,FV(25th/75th percentiles):11.6 (8.7/20.3): ΔE0,Inf:15.1 (11.4/19.5); pT0 = 0.135), ICDAS (pT0 = 0.920) and DD (pT0 = 0.367). At T1 and T2 ΔE values (pT1<0.001, pT2<0.001), ICDAS scores (pT1<0.001, pT2<0.001) and DIAGNOdent values (pT1 = <0.001, pT2 = <0.001) for Inf were significantly reduced whereas ΔE values (pT1 = 0.382, pT2 = 0.072) and ICDAS scores (pT1 = 0.268, pT2<0.001) for FV remained unchanged. CONCLUSIONS: Resin infiltration effectively masked ICL during treatment with fixed orthodontic appliances both immediately after application and at the last appointment before debonding. Furthermore, the visual appearance of fluoridated lesions was not as satisfactory as that of the infiltrated ones at both T1 and T2. CLINICAL SIGNIFICANCE: Resin infiltration effectively masked ICL during treatment with fixed orthodontic appliances both immediately after application and at the last appointment before debonding. Furthermore, the visual appearance of fluoridated lesions was not as satisfactory as that of the infiltrated ones immediately after first application as well as half a year after application. TRIAL REGISTRATION: German Clinical Trials Register (DRKS-ID: DRKS00011797).

Aesthetic caries infiltration - Long-term masking efficacy after 6 years.

OBJECTIVES: This study aimed to evaluate the masking efficacy of caries infiltration technique of initial caries lesions (ICL) six years after debonding and single treatment. METHODS: In 10 adolescents, 74 ICL (ICDAS 2) in 74 teeth were treated by resin infiltration (Icon, DMG) at a mean (SD) of 1.2 (1.2) months after bracket removal. The etching procedure was performed up to 3 times. Standardized digital images were taken before treatment (T0), seven days (T7) and 6 years (T2190) after treatment. Outcomes included the evaluation of the color differences between carious and healthy enamel at T0, T7 and T2190 by quantitative colorimetric analysis (ΔE), ICDAS scores, quantitative light-induced fluorescence (QLF; ΔF,ΔQ,WS Area) and qualitative visual evaluation (5-point Likert-scale [deteriorated (1), unchanged (2), improved, but not satisfying (3), improved and no further treatment required (4), completely masked (5)). RESULTS: The median color difference ΔΕ0 (25th/75th percentiles) at T0 was 10.3 (8.56/13.0). At T7 a significant decrease was observed (ΔΕ7=3.7 (2.0/5.8); p<0.001; Friedmann-test; ICDAS p<0.001; Chi-square test). No significant changes based on ΔΕ (p=0.972; Friedmann-test) and ICDAS grading (p=0.511, chi-square test) were observed between T7 and T2190 (ΔΕ2190=2.9 (1.8/4.2)). Furthermore, at T2190 four experienced dentists classified 50% and 37% of the lesions as "improved and no further treatment required" and "completely masked", respectively (Fleiss kappa: T2190: 0.782 (substantial agreement)). CONCLUSION: Aesthetic caries infiltration can effectively mask post-orthodontic initial caries lesions for at least 6 years. These results for most of the teeth could not only be observed by quantitative but also by qualitative analysis. CLINICAL SIGNIFICANCE: Resin infiltration efficaciously masks post-orthodontic initial carious lesions. The optical improvement can be observed directly after treatment and remains stable for at least six years.

Proximal caries infiltration - Pragmatic RCT with 4 years of follow-up.

OBJECTIVES: Efficacy of proximal caries infiltration to arrest lesion progression has been shown in university settings, but only once in a practice-based pragmatic design with a follow-up of 18 months. The aim of this randomized split-mouth placebo-controlled study was to follow-up this cohort for 3 years and those with high caries risk for 4 years. METHODS: Originally, in 87 children and young adults pairs of 238 proximal caries lesions, radiographically extending into inner half of enamel (E2) or outer third of dentin (D1), were randomly allocated to two groups: infiltration (Icon; DMG) or mock (control) treatment by five dentists in four private practices. All subjects received risk-related instructions for diet, flossing and fluoridation. The primary outcome was radiographic lesion progression (pairwise comparison) evaluated by two evaluators independently being blinded to treatment allocation. RESULTS: After 36 months [mean (SD): 1152 (166) days] 165 lesion pairs in 64 patients as well as after 48 months [mean (SD): 1496 (121) days] 71 lesion pairs in 20 high caries risk patients could be re-evaluated clinically as well as radiographically using individualized bitewing holders as at baseline. No adverse events could be observed. After 36 months, progression was recorded in 23/165 test (14%) and 64/165 control lesions (39%) [McNemar/Obuchowski test; p<0.001; relative risk reduction (CI95%): 64 (45-77%)]. After 48 months lesion progression was recorded in 13/71 test (18%) and 34/71 control lesions (48%) [p = 0.003; relative risk reduction (CI95%): 62 (34-78%)] of high caries risk patients. CONCLUSIONS: It can be concluded that also in a practice-setting proximal caries infiltration is more efficacious in reducing lesion progression compared with individualized non-invasive measures alone over a period of four years.

Effect of resin infiltration application on early proximal caries lesions in vitro.

BACKGROUND/PURPOSE: Resin infiltration (RI) material ICON is used in treating early proximal caries lesions, as it depends on a micro-invasive infiltration technology. This in vitro study aimed to evaluate the effect of ICON resin infiltration (RI) on early proximal caries by comparing surface roughness and hardness before and after treatment with RI using atomic force microscopy (AFM), automated microhardness testing system (AMHTS), and scanning electron microscopy (SEM) in vitro. MATERIALS AND METHODS: Twenty seven premolars extracted for orthodontic reasons were sectioned buccolingually, creating 54 specimens. Each specimen was immersed in demineralizing solution to induce caries. Only teeth with "International Caries Detection and Assessment System" codes 1 and 2 were selected. The specimens were divided randomly into either AFM, AMHTS or SEM groups, which examined demineralized enamel before and after treatment with ICON. RESULTS: The mean average surface roughness and root mean square roughness values of demineralized enamel treated with ICON were significantly higher than untreated lesions (P < 0.001). The mean Vickers hardness values for demineralized enamel treated with ICON was significantly higher than untreated lesions (P < 0.001). SEM showed irregular, pitted and rough demineralized enamel surface with destruction of enamel rods and dissolution of enamel crystals. After ICON application, the surface showed complete blockage of enamel rods with RI and irregular, rough uneven topography. CONCLUSION: RI application on proximal incipient caries increased surface roughness and hardness significantly.

Seven-year-efficacy of proximal caries infiltration - Randomized clinical trial.

OBJECTIVES: We report efficacy of resin infiltration to arrest progression of caries lesions as compared with non-invasive measures and oral hygiene education alone after a mean observation time of seven years. MATERIALS AND METHODS: This randomized split-mouth placebo-controlled clinical trial included 22 young adults having 29 pairs of interproximal non-cavitated caries lesions with radiographic extensions into inner half of enamel (E2) or outer third of dentin (D1). Lesion pairs were randomly allocated to two treatment groups: infiltration (Icon, pre-product; DMG) or mock (control) treatment. All subjects received risk-related instructions for diet, flossing and fluoridation. The primary outcome was radiographic (digital subtraction radiography) lesion progression after seven years. Secondly, Kaplan-Meier-analyses were applied to analyze time-to-failure additionally including patients followed up for less than 54 months as well. RESULTS: Two lesion pairs were excluded due to invasive treatment decision by another dentist, five lesion pairs were lost to follow-up prior to 54 months but included in the survival analysis. No unwanted effects could be observed. For the primary outcome in 17 patients followed up in mean for 84 months 2/22 infiltrated lesions (9 %) compared with 10/22 control lesions (45 %) progressed (p = 0.018). The relative risk reduction for test in relation to control was 80 % (CI 95 % = 19-95 %). For the survival analysis within a mean (SD) observation time of 73 (25) months mean failure rates of 1.3 % and 7.8 % could be observed for test and controls, respectively. Hazard risk (95 % CI) for caries progression was 6.6 (2-22) for the control compared with the test lesions (p = 0.002). CONCLUSIONS: We conclude that resin infiltration of proximal caries lesions extending radiographically around the enamel dentin junction is efficacious to reduce lesion progression after a mean observation time of seven years. CLINICAL SIGNIFICANCE: This randomized clinical trial proves that caries infiltration is highly efficacious compared with non-invasive measures and oral hygiene education alone after a considerably longer observation time of 7 years than studied so far before.

Influence of infiltrant application time on the reduction of opaqueness of proximal enamel caries.

INTRODUCTION: Infiltrant resins were developed to hamper carious lesion progression and mask the whitish appearance of first evidence of caries. OBJECTIVE: This study aimed at testing the hypothesis that a long application time of resin infiltrant in proximal enamel caries improves esthetic outcome compared to the commercially recommended time. MATERIALS AND METHODS: Twenty teeth with uncavitated inactive proximal white enamel caries lesions (selected by two calibrated examiners; inter-examiner κ = 0.87) were divided into two groups (experimental and control group; n = 10) that agreed regarding lesion surface area. Lesions were infiltrated following the protocol recommended by the manufacturer (two applications, 3 min application first and another 1 min application later; control) and by the protocol tested in this study (one application of 30 min; experimental). Enamel opaqueness (esthetic outcome) was measured by a calibrated examiner (intra-class coefficient of 0.9) before and after infiltration using fluorescence microscopy. RESULTS: Reduction of enamel opaqueness was significantly higher in the experimental group (40.0% ± 18.5%) than in the control group (18.6% ± 14.9%) (P = 0.0105, one-tailed t-test; Hedge's g of 1.28, 95% confidence interval of 0.43/2.13, and power of 86%). CONCLUSIONS: It can be concluded that the application time of 30 min provides a greater reduction in opaqueness of proximal enamel lesion compared to the application time recommended by the manufacturer. The high effect size could stimulate patients to comply with the treatment time.

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.

Evaluation of the value of re-wetting prior to resin infiltration of post-orthodontic caries lesions.

OBJECTIVES: Assessment of the influence of colour changes during the re-wetting process as a possible predictor for the final result after resin infiltration to mask post-orthodontic white spot lesions. MATERIALS AND METHODS: Resin infiltration (ICON; DMG, Hamburg, Germany) was performed according to the manufacturer's recommendation with the exception of repeated, at maximum three etching procedures based on the subjective decision of the dentist during a so called re-wetting process using ethanol. The masking effect by ethanol as well as after resin infiltration was evaluated by digital images taken before, for nine seconds during re-wetting and one week after treatment using CIE L*a*b* colour space. RESULTS: Twenty-nine patients (16 female) with a total of 221 lesions (ICDAS 2) were included (mean age 16 years). Mean time after debonding the orthodontic appliances was ten weeks. Colour changes during re-wetting, evaluated in the first ten patients (71 lesions) showed a significant correlation between the minimum ΔE observed during re-wetting and the final ΔE after resin infiltration (r = 0.65, p < 0.001; Spearman correlation). The main drop in ΔE becomes visible after three seconds when performing the re-wetting process. Regarding the 221 lesions, resin infiltration significantly reduced the colour difference between sound and lesion areas from a baseline ΔE (25th/75th percentiles) of 10.9 (8.2/13.2) to a ΔE of 4 (2.1/5.8) after one week (p < 0.001). The number of etching procedures correlated significantly with baseline ΔE (p < 0.05). CONCLUSIONS: The minimum ΔE observed during the re-wetting process seems to be a useful predictor for the final result of resin infiltration of post-orthodontic caries lesions. More prominent lesions with higher ΔE at baseline seem to require more erosion of the surface layer. In general, a significant and considerable clinical reduction of ΔE could be observed. CLINICAL SIGNIFICANCE: We corroborate that resin infiltration technique is a very useful method to mask caries lesions having developed during treatment with fixed orthodontic appliances. Colour changes while re-wetting the lesions with ethanol seem to be a valuable indicator for the number of required etching procedures.

Modified resin infiltration of non-, micro- and cavitated proximal caries lesions in vitro.

OBJECTIVE: Infiltrant resin (IR) is currently indicated for non-cavitated caries lesions. However, modifying the technique might expand its indication spectrum to micro-cavitated lesions. The present study aimed to evaluate the penetration/filling ability of a newly developed micro-filled infiltrant resin (MFIR) in non-, micro- and cavitated natural caries lesions. MATERIALS AND METHODS: Proximal lesions in 120 extracted human teeth with ICDAS-2 (n = 30), 3 (n = 45) and 5 (n = 45) lesions were etched with 15% hydrochloric acid gel for 2 min and allocated to one of the following treatments; IR: lesions (ICDAS-2, 3 and 5; each n = 15) were treated with commercial infiltrant resin for 3 min. MFIR: experimental MFIR [55 wt% IR plus 45 wt% organic fillers] was applied to lesions (ICDAS-2, 3 and 5; each n = 15) for 3 min. IR + FC: IR was applied for 3 min, light-cured, and cavities (ICDAS-3 and 5; each n = 15) filled with flowable composite (FC). Percentage infiltration of the demineralized enamel (Inf.%) and percentage filling of the cavity (Fill.%) were analyzed using dual-fluorescence staining and confocal microscopy. RESULTS: No significant differences in Inf.% (range of medians: 57%-100%) were observed between different treatments (p > 0.05; Kruskal-Wallis) within each ICDAS-code. Fill.% of cavities was significantly higher in groups MFIR (median in ICDAS-3/-5: 100%/100%) and IR + FC (100%/100%) than IR (25%/38%) (p < 0.05). CONCLUSION: MFIR showed similar penetration into natural lesions as the commercial infiltrant, but better ability to fill cavitated areas. CLINICAL RELEVANCE: MFIR and IR + FC might provide a new micro-invasive treatment for small cavitated proximal lesions.

Micro-filled resin infiltration of fissure caries lesions in vitro.

OBJECTIVES: The aim of this in vitro study was to evaluate three treatment modalities [infiltrant resin (IR), micro-filled infiltrant resin (MFIR), infiltrant-sealant-combination (ISC)] regarding both their abilities to penetrate lesions differing in ICDAS-codes and to fill fissures and cavities. MATERIALS AND METHODS: Extracted human molars (n=90) showing fissure caries lesions with and without cavitations were etched with 15% hydrochloric acid (HCl) that was mixed with abrasives and a 15% HCl-solution (1:1). The etching gel was rubbed for 30s within the fissure and, if eligible, within the cavity using a brush. After this pretreatment an infiltrant (Icon; DMG; IR) or an infiltrant mixed with microfillers (MFIR) was applied. ISC included the application of an infiltrant followed by a fissure sealant (Helioseal; Ivoclar Vivadent) From each tooth slices showing a non-cavitated (based on ICDAS-2) or cavitated lesion part (based on ICDAS-3/5) were prepared. Lesion (LA) and penetration areas (PA) as well as the completeness of fissure and cavity filling were analyzed using dual staining and confocal laser scanning microscopy. RESULTS: Percentage penetration (PP) was calculated as 100×PA/LA. PP [median (25th/75th)] did not differ significantly between IR [95 (86/100)%], MFIR [93 (62/100)%] or ISC [89 (67/97)%] (p>0.05; Kruskal-Wallis test). All three materials filled about 90% of the dimensions of fissures and cavities (p>0.05; Kruskal-Wallis test). CONCLUSION: It can be concluded that MFIR seems to be suitable to fill fissures and cavities like a fissure sealant and that it penetrates fissure caries lesions similarly deep as the conventional infiltrant after an experimental etching regime. CLINICAL SIGNIFICANCE: The MFIR seems to combine advantages of the fissure sealing and the caries infiltration procedure.

Penetration of micro-filled infiltrant resins into artificial caries lesions.

OBJECTIVES: Infiltrants are non-filled low-viscosity resins that have been developed to arrest lesion progression by penetrating into the porosities of non-cavitated lesions where they are hardened and arrest lesion progression. The addition of fillers to infiltrant resin might combine the high penetrativity of the former with the better applicability of composite resins. The aim of the present study was to evaluate the penetration of different experimental micro-filled infiltrant resins (MFIRs) into artificial enamel lesions. METHODS: An infiltrant (Icon; DMG) was mixed with either one of three fillers [OF83: organic filler (83µm), OF42: organic filler (42µm) or GF0.7: glass filler (0.7µm)] reaching 35, 45 and 55% filler content, respectively. In each of 180 bovine enamel specimens three artificial lesions were created; two lesions were etched for 5s (37% H3PO4), leaving one lesion as control. Specimens were randomly allocated to 10 groups, in which either one of the MFIRs or the infiltrant was applied onto the two etched lesions for either 5s or 10s (n=18/group). Percentage of penetration (PP) was calculated and analysed. RESULTS: For both application times a significant influence of filler size but not of filler concentration on PP could be revealed (p<0.05; two-way ANOVA). PP of MFIRs-OF42 was not significantly different from unfilled infiltrant but significantly higher than those of OF83 and GF0.7 (p<0.05; two-way ANOVA). CONCLUSIONS: MFIRs-OF42 showed the ability to penetrate into artificial enamel caries lesions similar to the unfilled infiltrant resin. CLINICAL SIGNIFICANCE: MFIRs could provide a new micro-invasive treatment for small-cavitated lesions.

Detection and treatment of proximal caries lesions: Milieu-specific cost-effectiveness analysis.

OBJECTIVES: Dental caries lesions are highly prevalent, concentrated in high-risk groups, and often affect proximal tooth surfaces. Choosing a caries detection method determines the available treatment options: radiographically detected early lesion stages might receive non-, micro-, or invasive treatments, whilst visually tactile detected lesions are often advanced and mostly require invasive treatment. Thus, the choice of detection method impacts on patients via the applied treatment. We compared the cost-effectiveness of combinations of detections and treatments of proximal lesions in different populations which did or did not receive prevention during adolescence. These cost-effectiveness comparisons of different detection-treatment combinations should aid clinical decision making and improve resource allocation. METHODS: A Markov-model was constructed to follow a proximal posterior surface in a 12-year-old German over his lifetime. Prevalence, validity and transition probabilities were extracted from the literature. Microsimulations were performed to evaluate costs (Euro) per tooth-retention-time (years). RESULTS: For populations with low risk, radiographic detection plus non-invasive treatment without (270 Euro, 61.5 years) and with prevention (312 Euro, 63.0 years), as well as radiographic detection plus micro-invasive treatment and prevention (373 Euro, 64.0 years) were cost-effective. For populations with high risk, radiographic detection plus micro-invasive treatment without (427 Euro, 58.5 years) and with prevention (436 Euro, 61.0 years) were cost-effective. Combinations involving invasive treatments had limited cost-effectiveness. CONCLUSIONS: Caries detection methods should be evaluated regarding the cost-effectiveness resulting from their use in different populations. CLINICAL SIGNIFICANCE: Caries detection methods are usually evaluated regarding their validity compared to a gold standard. We demonstrate that the cost-effectiveness stemming from using different detection methods additionally depends on the treatment options determined by different methods, and the examined population. Dentists' choice of a detection method should not only be guided by its validity, but also by its specific benefits in different populations.

Masking of white spot lesions by resin infiltration in vitro.

OBJECTIVES: The aim of this in vitro study was to evaluate the ability of one commercial and five experimental infiltrating resins (infiltrants) to camouflage enamel white spot lesions immediately after resin infiltration and after a staining period. METHODS: In each of 120 bovine enamel samples, two artificial caries lesions were created (windows A and C; pH=4.95, 50 days), whereas two windows were protected serving as sound controls (B and D). After etching windows C and D (37% phosphoric acid), specimens were randomly allocated to 6 groups. Either one of 5 experimental infiltrants or a commercial infiltrant (Icon, DMG) (refractive indices 1.50-1.55) was applied and light cured. After half of each specimen was polished, samples were remineralized (pH=7.0) and stained with tea and red wine for 50 days. Photographic images after various treatment steps were obtained. Color differences (ΔE) of untreated (A) and treated lesions (C) as well as infiltrated sound enamel (D) were compared with untreated enamel (B). RESULTS: All infiltrants showed significantly better color match with sound enamel (median ΔE [25th/75th percentile]: 2.2 [1.5/3.1]) than untreated controls (9.3 [8.0/10.9]) (p<0.001, Wilcoxon, post hoc Bonferroni). Moderate correlation between refractive index and ΔE of infiltrated lesions was demonstrated (R(2)=0.43, p>0.05). Staining was significantly reduced for polished infiltrated lesions compared to untreated or infiltrated unpolished lesions (p<0.001). CONCLUSIONS: Resin infiltration is suitable to mask artificial white spot lesions. Polished infiltrated lesions are resistant to staining in vitro. CLINICAL SIGNIFICANCE: Resin infiltration is a micro-invasive approach to camouflage post-orthodontic white spot lesions.