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Minimally invasive resin infiltration of arrested white-spot lesions
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Minimally invasive resin infiltration of arrested white-spot lesions: A randomized clinical trial Seth V. Senestraro, Jennifer J. Crowe, Mansen Wang, Alex Vo, Greg Huang, Jack Ferracane and David A. Covell, Jr. JADA 2013;144(9):997-1005 10.14219/jada.archive.2013.0225 The following resources related to this article are available online at jada.ada.org (this information is current as of July 16, 2014): Updated information and services including high-resolution figures, can be found in the online version of this article at: http://jada.ada.org/content/144/9/997
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Minimally invasive resin infiltration of arrested white-spot lesions A randomized clinical trial Seth V. Senestraro, DDS, MS; Jennifer J. Crowe, DDS, MS; Mansen Wang, PhD; Alex Vo, DMD; Greg Huang, DMD, MSD, MPH; Jack Ferracane, PhD; David A. Covell Jr., DDS, PhD
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AB STRACT A B STRACT Background. The authors conducted a
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randomized, single-masked clinical trial involving patients who had completed A orthodontic treatment to assess changes in the RT IC LE appearance of white-spot lesions (WSLs) that were treated with resin infiltration. Methods. The authors divided affected teeth into control and treatment groups. In the treatment group, they restored teeth with WSLs by using resin infiltration. They evaluated changes in WSLs photographically by using a visual analog scale (VAS) (0 = no change, 100 = complete disappearance) and area measurements (in square millimeters). The authors analyzed the data by using two-way analysis of variance. Results. The mean VAS ratings for treated teeth demon strated marked improvement relative to that for control teeth immediately after treatment (67.7 versus 5.2, P < .001) and eight weeks later (65.9 versus 9.2, P < .001). The results for treated teeth showed a mean reduction in WSL area of 61.8 percent immediately after treatment and 60.9 percent eight weeks later, compared with a -3.3 percent change for control teeth immediately after treatment and a 1.0 percent reduction eight weeks later. Conclusions. Resin infiltration significantly improved the clinical appearance of WSLs, with stable results seen eight weeks after treatment. Practical Implications. Resin infiltration, a minimally invasive restorative treatment, was shown to be effective for WSLs that formed during orthodontic treatment. Key Words. Resin infiltration; white-spot lesions; demineralization. JADA 2013;144(9):997-1005. T
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namel white-spot lesions (WSLs), an outcome of enamel demineralization, are common sequelae of poor oral hygiene. With orthodontic treatment, the presence of fixed appliances makes oral hygiene more difficult, increasing susceptibility to WSL formation.1,2 The reported prevalence of WSLs in orthodontic patients ranges from 4.9 percent3 to 97 percent,4 with investigators in a 2011 study reporting that 72.9 percent of patients developed a WSL during treatment.5 WSLs associated with subsurface enamel porosities are caused by a cyclical imbalance between demineralization and remineralization, resulting from an acidic environment created by cariogenic bacteria.6 With time, remineralization at the outer surface of the lesion decreases access of calcium and other ions to deeper portions of the lesion, resulting in an arrest of the remineralization process,2,7,8 which often is referred to as arrested WSLs. The lesion’s opaque white appearance is due to scattering of light at
At the time this study was conducted, Dr. Senestraro was a resident, Department of Orthodontics, School of Dentistry, Oregon Health & Science University, Portland. He now is in private practice in Milwaukie, Ore. Dr. Crowe is an assistant professor, Department of Orthodontics, School of Dentistry, Oregon Health & Science University, Portland. Dr. Wang is a biostatistical analyst, Banfield Applied Research & Knowledge, Banfield Pet Hospital, Portland, Ore. Dr. Vo is a resident, Department of Orthodontics, School of Dentistry, Oregon Health & Science University, Portland. Dr. Huang is a professor and chair, Department of Orthodontics, School of Dentistry, University of Washington, Seattle. Dr. Ferracane is a professor and chair, Department of Restorative Dentistry, Division of Biomaterials and Biomechanics, School of Dentistry, Oregon Health & Science University, Portland. Dr. Covell is an associate professor and chair, Department of Orthodontics, School of Dentistry, Oregon Health & Science University, 611 S.W. Campus Drive, Portland, Ore. 97239, e-mail [email protected]. Address reprint requests to Dr. Covell.
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the subsurface demineralized enamel.6,9 WSLs may regress naturally owing to salivary remineralization and toothbrush abrasion; however, complete regression does not occur for most lesions.10,11 Regression of WSLs after removal of orthodontic appliances occurs predominantly in the first three months, and lesions present after this time are likely to remain.12 Topical remineralization therapy is one treatment approach for WSLs. However, improvements from remineralization therapy that involve the use of casein phosphopeptide amorphous calcium phosphate,13 low-concentration fluoride14 or a combination of the two15 have been found to be minimal and often clinically insignificant.16,17 Bleaching also results in limited esthetic improvement and has been associated with tooth sensitivity and a reduction in enamel microhardness.18-20 In general, complete remineralization of WSLs does not occur with topical applications of various products.21 Other treatment options for WSLs include microabrasion and restoration. Although microabrasion can remove WSLs, the technique has the potential to remove large amounts of enamel.16,22 Tooth preparations for traditional resin-based composite restorations, veneers and crowns require removal of enamel beyond the demineralized zone and may extend into dentin.23 Because orthodontic WSLs predominantly affect a young patient population, long-term prognosis of the restored teeth is a significant concern. Considering the invasiveness of microabrasion or traditional restorations compared with the relatively small amount of demineralized enamel in WSLs, a less invasive restorative technique would be preferable. Resin infiltration has been marketed as a minimally invasive restorative treatment option and involves penetration of a resin into the body of the WSL, with minimal loss of enamel.24 With this method, the clinician uses an acid etchant to remove the outer layer of sound remineralized enamel, exposing the demineralized lesion body; he or she subsequently fills the lesion with a low-viscosity resin.24 The results of in vitro studies have shown significant masking of WSLs with use of resin infiltration techniques.25-27 Initial in vivo case report findings have been promising, showing immediate significant improvement in the appearance of WSLs.28,29 Although clinicians have used resin infiltration for restoration of teeth with interproximal incipient caries, no ran domized clinical trials, to our knowledge, have been conducted to evaluate resin infiltration of WSLs.
The purpose of this randomized, singlemasked clinical trial was to assess the esthetic improvement and changes in the area of WSLs treated with resin infiltration. Patients who had developed WSLs during orthodontic therapy were treated with a commercially available resin infiltration system. We obtained photographs of WSLs before treatment (T1), immediately after treatment (T2) and eight weeks later (T3). Using the photographs, orthodontists rated changes in the appearance of the WSLs and measured changes in the WSL area. Our hypothesis was that WSLs in teeth restored with resin infiltration would have an improved appearance and a reduced area compared with untreated WSLs. METHODS
The institutional review board at the Oregon Health & Science University, Portland, approved this study. Power analysis, assuming an estimated 70 percent improvement in appearance on the basis of changes in WSLs treated with resin infiltration reported in a previous study,29 indicated that a minimum sample size of 20 patients was needed to show significance at a power of 80 percent. Allowing for a 30 percent dropout rate, we set an enrollment goal of 30 participants. We allocated patients according to Consolidated Standards of Reporting Trials (CONSORT) guidelines (Figure 1).30 To recruit participants from the orthodontic clinic of the Oregon Health & Science University, the lead investigator (S.V.S.) searched patient records consecutively and retrospectively from December 2011 to December 2007. Initial screening for inclusion was based on intraoral photographs obtained immediately after removal of orthodontic appliances that showed WSLs on at least two maxillary anterior teeth. Additional inclusion criteria included an absence of preexisting (before orthodontic treatment) white spots determined on the basis of pretreatment photographs, patient age in the range from 12 through 30 years, no previous treatment of WSLs, at least three months having elapsed since removal of orthodontic appliances, WSLs having an International Caries Detection and Assessment System (ICDAS)31 score of 2 (that is, distinct visual change in enamel opacity) or 3 (localized enamel breakdown due to caries with no visible ABBREVIATION KEY. CONSORT: Consolidated Standards of Reporting Trials. ICDAS: International Caries Detection and Assessment System. NA: Not applicable. VAS: Visual analog scale. WSL: Whitespot lesion.
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dentin) and absence of active caries. Assessed for eligibility (n = 1,227) As we identified potential participants through records Excluded (n = 1,197) Enrollment reviews, one of us ● Not meeting inclusion criteria (n = 1,118) ● Declined to participate (n = 79) (S.V.S.) contacted them by telephone; if they agreed to parRandomized (n = 30) ticipate in the study, an appointment Allocation was scheduled for a clinical examination and WSL treatment. Allocated to intervention (n = 30) During the clinical ● Received allocated intervention (n = 23) ● Did not receive allocated intervention (did examination, the not keep appointment) (n = 7) clinician (S.V.S.) confirmed the presence Teeth randomly allocated to of WSLs by using Follow-up intervention and nonintervention the ICDAS.31 Other groups information collected Lost to follow-up (did not keep appointment) (n = 3) from the patient’s Discontinued intervention (n = 0) record included sex, age, length of time Analysis in orthodontic appliances and time elapsed since removal Analyzed (n = 20) ● Excluded from analysis (n = 0) of the orthodontic appliances. For each participant, we used an electronic random Figure 1. Flow diagram, according to Consolidated Standards of Reporting Trials (CONSORT).30 number generator to select one affected tooth to serve as a control on each tooth in the treatment group for five (no treatment), and we assigned the remaining seconds by using a fine-grit polishing disk (EP teeth to the treatment group. Owing to reports Esthetic Polishing Kit, Brasseler, Savannah, of variable responses to treatment,27,28 allocation Ga.) in a slow-speed handpiece. The purpose of teeth was biased toward the treatment group of this step was to maximize the potential for to maximize the number of teeth treated. resin infiltration of long-standing WSLs. The Resin infiltration. The clinician (S.V.S. or clinician then placed a 15 percent hydrochloric another dentist) followed the resin infiltration acid gel (Icon Etch, DMG America) on the WSL (Icon Infiltrant, DMG America, Englewood, N.J.) for two minutes, being careful to avoid contact protocol in the manufacturer’s instructions, exwith gingival tissue, followed by a water rinse cept for the method of tooth isolation and use of and compressed air drying (each for 30 seconds). mild abrasion. Rather than using a rubber dam, The etch, rinse and dry steps were repeated, as directed in the instructions, he or she placed a after which the clinician desiccated the lesions dry-field isolation system (Nola, Great Lakes Orby using ethanol (Icon Dry, DMG America) and thodontics, Tonawanda, N.Y.) for unobstructed air dried them for 30 seconds. The practitioner access to enamel adjacent to gingival margins. applied the resin infiltrant (Icon Infiltrant) to The clinician cleaned the teeth in both groups the tooth surface and allowed it to penetrate the with a rubber cup and plain pumice (Integra lesion for three minutes. A cotton roll was used Miltex, York, Pa.), rinsed them for 30 seconds to wipe excess material from the surface, and and air dried them for 30 seconds; he or she then the material then was light cured (1,600 milobtained photographs (T1). liwatts/square centimeter) for 40 seconds. The On the basis of a discussion between the clinician again applied the resin infiltrant for lead investigator and a representative of DMG one minute, removed the excess and light cured America (Steve Richard, oral communication, the material for 40 seconds. Dental floss was May 5, 2012), the clinician abraded the WSL used to remove the excess resin from the proxiJADA 144(9) http://jada.ada.org September 2013 999 Copyright © 2013 American Dental Association. All Rights Reserved.
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mal spaces, and the clinician polished the facial surface by using a mildly abrasive polishing cup (Enhance, Dentsply, York, Pa.). After the infiltration treatment (T2), the clinician evaluated all teeth by recording the ICDAS score and noting any irregularity of the restoration; he or she then photographed the teeth. A staff member gave patients oral hygiene supplies (toothbrush, fluoride toothpaste and dental floss) and instructions for home care. At the patients’ follow-up visit eight weeks later (T3), the clinician isolated their anterior teeth; cleaned them with flour of pumice; and rinsed, air dried, evaluated and photographed them. Photographs and orthodontists’ evaluations of WSLs. The clinician obtained photographs of each tooth with WSLs at the three time points by using a digital camera (Nikon D60, Nikon, Tokyo) with a macro lens (100-mm Macro Rokkor-X, Minolta [now Konica Minolta], Tokyo) and a point-source flash positioned at a fixed focal distance from the patient. The clinician dried the tooth surfaces immediately before obtaining the images to prevent moisture from influencing the WSL’s appearance. One of us (A.V.) cropped the photographs of the teeth and placed them into slide presentation software. For each tooth, we showed the images to the raters side by side, with the T1 image on the left and the T2 or T3 image on the right. We randomly sequenced the slides, showing the image pairs among control and experimental teeth and among time points. Owing to the large number of comparisons (n = 152), we gave each rater one of two sequenced versions of the slides to mitigate potential systematic bias resulting from rater fatigue. Each sequence included 20 repeated image pairs to assess intrarater reliability. Five raters (J.J.C., D.A.C., and three other orthodontic faculty members) underwent technique calibration through a series of six slides. They then rated esthetic changes of the WSL for each tooth by marking a 100-millimeter visual analog scale (VAS); 0 indicated no improvement and 100 represented complete disappearance of the WSL. To quantify the ratings, an investigator (S.V.S.) measured the distance in millimeters from the 0 end of the VAS to the rater’s mark. WSL area calculation. The lead investigator encoded image file names to mask the time point of the image (that is, T1, T2 or T3). Another investigator (A.V.) outlined and measured WSL areas for each of the three time points by using an image analysis program (ImageJ, National Institutes of Health, Bethesda, Md.) that was calibrated from a photograph of a ruler obtained at the fixed focal distance. He used the
area (in square millimeters) of each tooth and corresponding WSL to calculate the percentage change in the WSL area by comparing the T1 image with the T2 image and the T1 image with the T3 image. To evaluate method error, the investigator repeated measurements of 20 teeth several days later. Statistical analysis. We averaged the VAS results from the five raters for each tooth and time point and analyzed them by using repeated-measures analysis of variance (ANOVA). We also analyzed the percentage change in the area of the WSL measurements by using repeated-measures ANOVA. In addition, we analyzed the factors of age, sex, time elapsed since appliance removal, treatment duration, tooth type and initial WSL severity by using repeated-measures ANOVA for the effect on the VAS rating and on the percentage change in area for teeth in the treatment group. We calculated interrater reliability for the VAS method by using Pearson correlation coefficients.32 We also used Pearson correlation coefficients to measure intrarater reliability for the VAS and for area calculation methods.32 We used the Dahlberg formula to calculate method error for area measurements.33 RESULTS
Enrollment. In February 2012, the lead investigator reviewed 1,227 patient records and identified 109 patients as meeting the inclusion criteria (Figure 1). When potential participants were contacted, 79 declined and 30 agreed to enroll. Subsequently, seven participants failed to keep their initial appointment (T1) and three failed to keep their posttreatment follow-up appointment (T3), resulting in a total of 20 participants completing the study. Among those who completed the study, a total of 66 teeth met the inclusion criteria; we allocated 46 of these teeth to the treatment group and 20 served as controls (no intervention). Although we did not time the procedure systematically, treating three teeth per patient required approximately 25 minutes. Clinical examination. The clinician observed a stippled surface texture, not expected before treatment, at T2 and T3 on most teeth restored with resin infiltration. He did not observe any other irregularities in resin infiltration restorations. We did not include ICDAS data in the final analysis owing to the low number of teeth (n = 4) having an ICDAS score of 3 at T1. All teeth in the treatment group that had an ICDAS score of 3 at T1 had an ICDAS score of 2 at T2 and T3.
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Orthodontists’ evaluations of WSLs. Teeth that underwent treatment (Figures 2 through 4) had significantly higher VAS ratings (Figure 5) than did control teeth. At T2, the mean VAS rating for teeth that received treatment was 67.7 compared with 5.2 for control teeth (P < .001) (Figure 5). At T3, the mean VAS rating for teeth that received treatment was 65.9 compared with 9.2 for control teeth (P < .001) (Figure 5). In both the treatment and control groups, we found no significant difference in VAS ratings when comparing changes at T2 with those at T3. The factors of age, sex, tooth type, time in orthodontic appliances, time elapsed since appliance removal and initial WSL severity did not have a significant effect on VAS ratings in treated teeth (Table). Pearson correlation coefficients were high for intrarater reliability, ranging from r = 0.97 to 0.99 for the five raters. The Pearson correlation coefficient for interrater reliability also was strong (r = 0.97) among the five raters. Standard deviations (SDs) for the VAS ratings were relatively wide at T2 (SD = 22.3) and T3 (SD = 26.6) for teeth treated with resin infiltration (Figures 5 and 6, page 1003). WSL area calculations. At T2, the mean percentage reduction in WSL area was 61.8 percent for teeth receiving treatment compared with -3.3 percent for control teeth (P < .001) (Figure 7, page 1003). Similarly, at T3, the mean percentage reduction was 60.9 percent for teeth receiving treatment compared with 1.0 percent for control teeth (P < .001) (Figure 7). The results showed no significant difference in percentage reduction between T2 and T3 in both the treatment and control groups. Standard deviations were relatively wide at T2 (SD = 23.9 percent) and at T3 (SD = 24.2 percent) for teeth treated with resin infiltration. Method error for area measurement was 0.47 mm2 relative to the initial WSL areas that ranged from 1.1 mm2 to 42.9 mm2. The factors of age, sex, time elapsed since appliance removal, treatment duration, tooth type and initial WSL severity did not have a significant effect on the percentage reduction in WSL area in treated teeth (Table). DISCUSSION
Although Davila and colleagues described resin infiltration as a restorative treatment for WSLs nearly 40 years ago, Kielbassa and colleagues24 proposed that advances in technique and materials have resulted in a more effective approach. Consistent with this assertion, the results of our study—in which we used VAS ratings of changes in WSL appearance and area 34
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Figure 2. Photographs depicting an above-average response to resin infiltration treatment. Left, tooth at T1 (before treatment). Right, tooth at T3 (eight weeks after treatment). Mean visual analog scale rating (on a 0-to-100–millimeter scale), 89; percentage reduction in area of the white-spot lesion, 81 percent.
Figure 3. Photographs depicting an average response to resin infiltration treatment. Left, tooth at T1 (before treatment). Right, tooth at T3 (eight weeks after treatment). Mean visual analog scale rating (on a 0-to-100–millimeter scale), 70; percentage reduction in area of the white-spot lesion, 58 percent.
Figure 4. Photographs depicting a below-average response to resin infiltration treatment. Left, tooth at T1 (before treatment). Right, tooth at T3 (eight weeks after treatment). Mean visual analog scale rating (on a 0-to-100–millimeter scale), 19; percentage reduction in area of the white-spot lesion, 23 percent.
measurements of the lesions—show that resin infiltration can predictably and significantly improve the esthetics of most teeth. Our results are similar to those reported by Kim and colleagues29 in a postorthodontic treatment case JADA 144(9) http://jada.ada.org September 2013 1001
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TABLE
Factors assessed for correlations with VAS* ratings and percentage reduction in WSL† area among treated teeth, T1‡ to T2 § . Factor
Standard deviation
Minimum
Maximum
P Value VAS
P Value PERCENTAGE reduction in WSL area
No. of patients or teeth
Mean
Age, in Years
20
16.6
1.8
14
21
.194
.391
Sex
20
NA ¶
NA
NA
NA
.906
.422
Time in Orthodontic Appliances, in months
20
32.5
8.4
21
48
.639
.592
Time Elapsed After Removal of Orthodontic Appliances, in Months
20
12.3
11.1
3
48
.177
.256
Tooth Type #
46
NA
NA
NA
NA
.155
.306
Severity (Percentage of Tooth Surface With WSLs at T1)
46
25.0
16.2
1.6
79.1
.283
.712
* VAS: Visual analog scale. † WSL: White-spot lesion. ‡ T1: Before treatment. § T2: Immediately after treatment. ¶ NA: Not applicable. # Central incisor, lateral incisor or canine.
standing, we also abraded all of them mildly for five seconds 90 before etching to enhance the effectiveness of the etchant 80 and subsequent infiltration 70 by reducing the superficial 60 layer of remineralized enamel. 50 (According to Wayne Flavin, 40 Director of Scientific Affairs, 30 DMG America, oral com20 munication, July 25, 2013, the abrasion step would not 10 be needed for newly formed 0 Control Treatment WSLs and, thus, more enamel would be preserved.) The GROUP variation in outcomes for teeth treated with resin infiltration T2 T3 may have been due to differences in lesion anatomy, with Figure 5. Mean (standard deviation) visual analog scale (VAS) ratings, according to group the thickness of the superficial and time. Treatment teeth exhibited statistically higher VAS ratings than did control teeth at T2 (immediately after treatment) and at T3 (eight weeks after treatment) (both P < remineralized layer likely be.001). Within the control teeth group and within the treatment teeth group, there was no ing the biggest factor.26 statistically significant difference in VAS ratings between T2 and T3. Researchers have reported series in which 17 of 18 WSLs treated with considerable variation in thickness of the reresin infiltration were partially or completely mineralized layer, with the majority of lesions masked. having a surface-layer thickness of between The resin infiltration method used in our 20 and 60 micrometers.35,36 Although we did study entailed minor modifications to the not measure the amount of enamel removed, manufacturer’s instructions. We used the Nola it is possible that teeth in the treatment group isolation system because use of a rubber dam, that achieved better outcomes underwent more as suggested by the manufacturer to prevent complete removal of this remineralized layer, moisture contamination and protect the ginwhereas those with little WSL improvement giva from the hydrochloric acid etchant, would may have undergone insufficient removal of have interfered with access to WSLs near the enamel. Measuring the amount of surface regingival margins. Because the WSLs were longmoved by the abrasion procedure and correlatVAS RATING
100
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PERCENTAGE CHANGE IN AREA
MEAN VAS RATING
ing this with the effectiveness of the resin infiltration treatment 100 ◆ ◆ ◆ ◆ ◆ ◆ ◆ should be a topic for future ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ 80 ◆ investigation. ◆ ◆ ◆ ◆ ◆ ◆ ◆ Measuring outcomes. We ◆ ◆ ◆ ◆ ◆ 60 ◆ ◆ designed the WSL evaluation ◆ ◆ ◆ ◆ ◆ ◆ method to provide a subjective ◆ ◆ 40 (VAS rating) and an objective ◆ ◆ ◆ ◆ (area measurement) approach for ◆ 20 ◆ ◆ measuring outcomes. Despite the ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ availability of technology-based 0 ◆ ◆ ◆ ◆ ◆ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 methods for WSL evaluation (for example, quantitative light fluoPATIENT rescence), results of visual evaluations of photographs have been ◆ Treatment teeth ◆ Control teeth found to most closely match patients’ perceptions of esthetic conFigure 6. Mean visual analog scale (VAS) ratings at T3 (eight weeks after treatment) cerns.37 The main disadvantages for each tooth, according to patient. Note that treatment results for some patients of the WSL rating methods used were relatively consistent among teeth, whereas other patients experienced greater in this study relate to bias and variability. Most control teeth exhibited relatively minimal to no change in VAS ratings. lack of validity.37 We addressed these limitations by masking all 100 raters and by specifying inclu90 sion criteria that resulted in the 80 elimination of patients who had WSLs present before orthodontic 70 treatment or WSLs that had been 60 treated previously. The reliabil50 ity of the assessment methods 40 used was demonstrated by the relatively low method error (0.47 30 mm2) for the area measurements 20 and by strong intrarater (mean r 10 = 0.98) and interrater (r = 0.97) 0 reliability for the VAS ratings. The patient’s sex, age, time –10 Control Treatment in orthodontic appliances, time elapsed since appliance removal, GROUP tooth type and initial WSL severity had no statistically significant T2 T3 effect on outcomes for WSLs in teeth restored with resin infiltraFigure 7. Percentage change in area (in square millimeters) of the white-spot lesion tion. The insufficient improvefrom T1 (before treatment) to T2 (immediately after treatment) and from T1 to T3 ment in some teeth likely relates (eight weeks after treatment). Treated teeth exhibited a high percentage reduction to the methods used in this study, compared with control teeth at T2 and T3 (both P < .001). Comparisons within the control teeth group and the treated teeth group revealed no differences between T2 in particular the selection criand T3 measurements. teria. For example, we defined initial severity as the percentage of the tooth factors could account, in part, for the somewhat covered by WSLs at T1, and we did not take into high standard deviations found in our study and account other anatomical factors such as lesion present potential topics for future investigation. depth, a variable that could potentially influWith broadened selection criteria, it may be posence the results.26 Furthermore, it is known that sible to determine whether the patient’s age and enamel becomes less permeable with age38,39 and duration of the WSLs affect the results of resin that the remineralized surface layer thickness infiltration restoration. of WSLs may increase with time elapsed after Although WSLs often are unesthetic, the reremoval of orthodontic appliances, thus resultsults of previous studies have shown that they ing in improvements in oral hygiene.35 Such are stable in the long term and usually do not JADA 144(9) http://jada.ada.org September 2013 1003 Copyright © 2013 American Dental Association. All Rights Reserved.
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progress to caries.2,4 In this study, variations in assessment outcomes for control teeth at all time points were negligible. Among the treated teeth, clinical examinations at T2 and T3 revealed no open margins, ledges or wear. However, it is likely that, as with traditional anterior resin-based composites, the resin material may, over time, stain relative to adjacent enamel, thus compromising esthetics.40,41 Although the stippled surface texture that raters observed on close examination of the restorations could be viewed as a minor defect, we found that the texture could be removed easily at a later date with use of more aggressive polishing disks (data not shown). Investigators have found that with interproximal incipient carious lesions, the defects can be predictably infiltrated,24 the caries progression rate is reduced26 and placement of more invasive restorations can be delayed.42 Although the restored teeth in our study were stable over the eight-week period, long-term in vivo outcomes for resin infiltration restorations in teeth with WSLs have yet to be documented, to our knowledge. Effectiveness of resin infiltration. Results of this study are consistent with those of previous studies in which investigators showed that because resin infiltration is effective and relatively noninvasive, the approach has advantages over other options for the treatment of WSLs.24,36,42 High-concentration fluoride treatment has been contraindicated as this enhances remineralization of the superficial layer of the lesion, accelerating the arrest of remineralization in the subsurface portion of the WSL.43,44 Although microabrasion has been shown to reduce WSLs, resulting in 83 to 97 percent reductions in area, the procedure also removes up to 360 µm of the demineralized enamel.16,18,22,45 By comparison, the two rounds of etching with hydrochloric acid, as used in this study, have been shown to remove approximately 80 µm of affected enamel.35 Paris and colleagues46 demonstrated in vitro that resin infiltration can exceed a depth of 400 µm, making complete infiltration of deeper WSLs possible. Traditional resin-based composite restorations, veneers and crowns require removal of enamel, and matching natural tooth shade and opacity with those of the restoration can pose esthetic challenges, especially in the anterior region. The resin used in this study (Icon Infiltrant) is unfilled and has optical properties similar to those of natural enamel, effectively transmitting the natural shade of the tooth.25 Thus, if resin infiltration is shown to be stable in the long term, it may prove to be the treatment of choice for WSLs that fail to regress naturally.
CONCLUSIONS
The results of our study show that resin infiltration significantly improved the clinical appearance of WSLs and reduced their size. In addition, the clinical appearance of teeth with WSLs restored with resin infiltration was stable over the eight-week study period. n Disclosure. None of the authors reported any disclosures. This project was funded by the Oregon Health & Science University Foundation, Orthodontic Support Fund, Portland. The authors thank DMG America, Englewood, N.J., for donating the resin infiltrant (Icon Infiltrant), Rachel Yamakawa, DDS, for help with placing the restorations and Amy Trevor, DMD, and Will Marra (dental student) for their assistance in managing patients’ records and study records. 1. Geiger AM, Gorelick L, Gwinnett AJ, Benson BJ. Reducing white-spot lesions in orthodontic populations with fluoride rinsing. Am J Orthod Dentofacial Orthop 1992;101(5):403-407. 2. Øgaard B, Rølla G, Arends J, ten Cate J. Orthodontic appliances and enamel demineralization, part 2: prevention and treatment of lesions. Am J Orthod Dentofacial Orthop 1988;94(2):123-128. 3. Boersma J, Van der Veen M, Lagerweij M, Bokhout B, PrahlAndersen B. Caries prevalence measured with QLF after treatment with fixed orthodontic appliances: influencing factors. Caries Res 2005;39(1):41-47. 4. Gorelick L, Geiger AM, Gwinnett AJ. Incidence of white-spot formation after bonding and banding. Am J Orthod 1982;81(2):93-98. 5. Richter AE, Arruda AO, Peters MC, Sohn W. Incidence of caries lesions among patients treated with comprehensive orthodontics. Am J Orthod Dentofacial Orthop 2011;139(5):657-664. 6. Chang H, Walsh L, Freer T. Enamel demineralization during orthodontic treatment: aetiology and prevention. Aust Dent J 1997;42(5):322-327. 7. García-Godoy F, Hicks MJ. Maintaining the integrity of the enamel surface: the role of dental biofilm, saliva and preventive agents in enamel demineralization and remineralization. JADA 2008;139(suppl 2):25S-34S. 8. Øgaard B. White-spot lesions during orthodontic treatment: mechanisms and fluoride preventive aspects. Semin Orthod 2008; 14(3):183-193. 9. Benson P, Shah A, Millett D, Dyer F, Parkin N, Vine R. Fluorides, orthodontics and demineralization: a systematic review. J Orthod 2005;32(2):102-114. 10. Årtun J, Brobakken BO. Prevalence of carious white-spots after orthodontic treatment with multibonded appliances. Eur J Orthod 1986;8(4):229-234. 11. Øgaard B. Prevalence of white-spot lesions in 19-year-olds: a study on untreated and orthodontically treated persons 5 years after treatment. Am J Orthod Dentofacial Orthop 1989;96(5):423-427. 12. AI-Khateeb S, Forsberg CM, de Josselin de Jong E, AngmarMånsson B. A longitudinal laser fluorescence study of white-spot lesions in orthodontic patients. Am J Orthod Dentofacial Orthop 1998;113(6):595-602. 13. Bailey D, Adams G, Tsao C, et al. Regression of post-orthodontic lesions by a remineralizing cream. J Dent Res 2009;88(12):1148-1153. 14. Bishara SE, Ostby AW. White-spot lesions: formation, prevention, and treatment. Semin Orthod 2008;14(3):174-182. 15. Beerens MW, van der Veen MH, van Beek H, ten Cate JM. Effects of casein phosphopeptide amorphous calcium fluoride phosphate paste on white-spot lesions and dental plaque after orthodontic treatment: a 3-month follow-up. Eur J Oral Sci 2010;118(6):610-617. 16. Akin M, Basciftci FA. Can white-spot lesions be treated effectively? Angle Orthod 2012;82(5):770-775. 17. Huang GJ, Roloff-Chiang B, Mills BE, et al. Effectiveness of MI Paste Plus and PreviDent fluoride varnish for treatment of whitespot lesions: a randomized controlled trial. Am J Orthod Dentofacial Orthop 2013;143(1):31-41. 18. Basting RT, Rodrigues AL Jr, Serra MC. The effects of seven carbamide peroxide bleaching agents on enamel microhardness over time. JADA 2003;134(10):1335-1342. 19. Haywood VB, Leonard RH, Nelson CF, Brunson WD. Effective-
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COVER ness, side effects and long-term status of nightguard vital bleaching. JADA 1994;125(9):1219-1226. 20. Knösel M, Attin R, Becker K, Attin T. External bleaching effect on the color and luminosity of inactive white-spot lesions after fixed orthodontic appliances. Angle Orthod 2007;77(4):646-652. 21. Reynolds E. Remineralization of enamel subsurface lesions by casein phosphopeptide-stabilized calcium phosphate solutions. J Dent Res 1997;76(9):1587-1595. 22. Murphy TC, Willmot DR, Rodd HD. Management of postorthodontic demineralized white lesions with microabrasion: a quantitative assessment. Am J Orthod Dentofacial Orthop 2007;131(1):27-33. 23. Summitt JB, Robbins JW, Hilton TJ, Schwartz RS, dos Santos J. Fundamentals of Operative Dentistry: A Contemporary Approach. 3rd ed. Hanover Park, Ill.: Quintessence; 2006:455-506. 24. Kielbassa AM, Muller J, Gernhardt CR. Closing the gap between oral hygiene and minimally invasive dentistry: a review on the resin infiltration technique of incipient (proximal) enamel lesions. Quintessence Int 2009;40(8):663-681. 25. Paris S, Meyer-Lueckel H. Masking of labial enamel whitespot lesions by resin infiltration: a clinical report. Quintessence Int 2009;40(9):713-718. 26. Gray G, Shellis P. Infiltration of resin into white-spot carieslike lesions of enamel: an in vitro study. Eur J Prosthodont Restor Dent 2002;10(1):27-32. 27. Rocha Gomes Torres C, Borges AB, Torres LM, Gomes IS, de Oliveira RS. Effect of caries infiltration technique and fluoride therapy on the colour masking of white-spot lesions. J Dent 2011;39(3):202-207. 28. Neuhaus KW, Graf M, Lussi A, Katsaros C. Late infiltration of post-orthodontic white-spot lesions. J Orofac Orthop 2010;71(6): 442-447. 29. Kim S, Kim EY, Jeong TS, Kim JW. The evaluation of resin infiltration for masking labial enamel white-spot lesions. Int J Paediatr Dent 2011;21(4):241-248. 30. Schulz KF, Altman DG, Moher D; CONSORT Group. CONSORT 2010 statement: updated guidelines for reporting parallel group randomized trials. Open Med 2010;4(1):e60-e68. 31. Ormond C, Douglas G, Pitts N. The use of the International Caries Detection and Assessment System (ICDAS) in a National
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Health Service general dental practice as part of an oral health assessment. Prim Dent Care 2010;17(4):153-159. 32. Rodgers JL, Nicewander WA. Thirteen ways to look at the correlation coefficient. Am Stat 1988;42(1):59-66. 33. Harris EF, Smith RN. Accounting for measurement error: a critical but often overlooked process. Arch Oral Biol 2009;54(suppl): S107-S117. 34. Davila JM, Buonocore MG, Greeley CB, Provenza DV. Adhesive penetration in human artificial and natural white-spots. J Dent Res 1975;54(5):999-1008. 35. Meyer-Lueckel H, Paris S, Kielbassa A. Surface layer erosion of natural caries lesions with phosphoric and hydrochloric acid gels in preparation for resin infiltration. Caries Res 2007;41(3):223-230. 36. Meyer-Lueckel H, Paris S. Improved resin infiltration of natural caries lesions. J Dent Res 2008;87(12):1112-1116. 37. Benson PE. Evaluation of white-spot lesions on teeth with orthodontic brackets. Semin Orthod 2008;14(3):200-208. 38. Kotsanos N, Darling A. Influence of posteruptive age of enamel on its susceptibility to artificial caries. Caries Res 1991;25(4):241-250. 39. Park S, Wang DH, Zhang D, Romberg E, Arola D. Mechanical properties of human enamel as a function of age and location in the tooth. J Mater Sci Mater Med 2008;19(6):2317-2324. 40. Crumpler D, Heymann H, Shugars D, Bayne S, Leinfelder K. Five-year clinical investigation of one conventional composite and three microfilled resins in anterior teeth. Dent Mater 1988;4(4): 217-222. 41. Smales R, Gerke D. Clinical evaluation of four anterior composite resins over five years. Dent Mater 1992;8(4):246-251. 42. Paris S, Meyer-Lueckel H. Infiltrants inhibit progression of natural caries lesions in vitro. J Dent Res 2010;89(11):1276-1280. 43. Willmot D. White lesions after orthodontic treatment: does low fluoride make a difference? J Orthod 2004;31(3):235-242. 44. Ogaard B. The cariostatic mechanism of fluoride. Compend Contin Educ Dent 1999;20(1 suppl):10-17. 45. Tong L, Pang M, Mok N, King N, Wei S. The effects of etching, micro-abrasion, and bleaching on surface enamel. J Dent Res 1993;72(1):67-71. 46. Paris S, Meyer-Lueckel H, Kielbassa AM. Resin infiltration of natural caries lesions. J Dent Res 2007;86(7):662-666.
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Minimally invasive resin infiltration of arrested white-spot lesions: A randomized clinical trial Seth V. Senestraro, Jennifer J. Crowe, Mansen Wang, Alex Vo, Greg Huang, Jack Ferracane and David A. Covell, Jr. JADA 2013;144(9):997-1005 10.14219/jada.archive.2013.0225 The following resources related to this article are available online at jada.ada.org (this information is current as of July 16, 2014): Updated information and services including high-resolution figures, can be found in the online version of this article at: http://jada.ada.org/content/144/9/997
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Minimally invasive resin infiltration of arrested white-spot lesions A randomized clinical trial Seth V. Senestraro, DDS, MS; Jennifer J. Crowe, DDS, MS; Mansen Wang, PhD; Alex Vo, DMD; Greg Huang, DMD, MSD, MPH; Jack Ferracane, PhD; David A. Covell Jr., DDS, PhD
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randomized, single-masked clinical trial involving patients who had completed A orthodontic treatment to assess changes in the RT IC LE appearance of white-spot lesions (WSLs) that were treated with resin infiltration. Methods. The authors divided affected teeth into control and treatment groups. In the treatment group, they restored teeth with WSLs by using resin infiltration. They evaluated changes in WSLs photographically by using a visual analog scale (VAS) (0 = no change, 100 = complete disappearance) and area measurements (in square millimeters). The authors analyzed the data by using two-way analysis of variance. Results. The mean VAS ratings for treated teeth demon strated marked improvement relative to that for control teeth immediately after treatment (67.7 versus 5.2, P < .001) and eight weeks later (65.9 versus 9.2, P < .001). The results for treated teeth showed a mean reduction in WSL area of 61.8 percent immediately after treatment and 60.9 percent eight weeks later, compared with a -3.3 percent change for control teeth immediately after treatment and a 1.0 percent reduction eight weeks later. Conclusions. Resin infiltration significantly improved the clinical appearance of WSLs, with stable results seen eight weeks after treatment. Practical Implications. Resin infiltration, a minimally invasive restorative treatment, was shown to be effective for WSLs that formed during orthodontic treatment. Key Words. Resin infiltration; white-spot lesions; demineralization. JADA 2013;144(9):997-1005. T
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namel white-spot lesions (WSLs), an outcome of enamel demineralization, are common sequelae of poor oral hygiene. With orthodontic treatment, the presence of fixed appliances makes oral hygiene more difficult, increasing susceptibility to WSL formation.1,2 The reported prevalence of WSLs in orthodontic patients ranges from 4.9 percent3 to 97 percent,4 with investigators in a 2011 study reporting that 72.9 percent of patients developed a WSL during treatment.5 WSLs associated with subsurface enamel porosities are caused by a cyclical imbalance between demineralization and remineralization, resulting from an acidic environment created by cariogenic bacteria.6 With time, remineralization at the outer surface of the lesion decreases access of calcium and other ions to deeper portions of the lesion, resulting in an arrest of the remineralization process,2,7,8 which often is referred to as arrested WSLs. The lesion’s opaque white appearance is due to scattering of light at
At the time this study was conducted, Dr. Senestraro was a resident, Department of Orthodontics, School of Dentistry, Oregon Health & Science University, Portland. He now is in private practice in Milwaukie, Ore. Dr. Crowe is an assistant professor, Department of Orthodontics, School of Dentistry, Oregon Health & Science University, Portland. Dr. Wang is a biostatistical analyst, Banfield Applied Research & Knowledge, Banfield Pet Hospital, Portland, Ore. Dr. Vo is a resident, Department of Orthodontics, School of Dentistry, Oregon Health & Science University, Portland. Dr. Huang is a professor and chair, Department of Orthodontics, School of Dentistry, University of Washington, Seattle. Dr. Ferracane is a professor and chair, Department of Restorative Dentistry, Division of Biomaterials and Biomechanics, School of Dentistry, Oregon Health & Science University, Portland. Dr. Covell is an associate professor and chair, Department of Orthodontics, School of Dentistry, Oregon Health & Science University, 611 S.W. Campus Drive, Portland, Ore. 97239, e-mail [email protected]. Address reprint requests to Dr. Covell.
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the subsurface demineralized enamel.6,9 WSLs may regress naturally owing to salivary remineralization and toothbrush abrasion; however, complete regression does not occur for most lesions.10,11 Regression of WSLs after removal of orthodontic appliances occurs predominantly in the first three months, and lesions present after this time are likely to remain.12 Topical remineralization therapy is one treatment approach for WSLs. However, improvements from remineralization therapy that involve the use of casein phosphopeptide amorphous calcium phosphate,13 low-concentration fluoride14 or a combination of the two15 have been found to be minimal and often clinically insignificant.16,17 Bleaching also results in limited esthetic improvement and has been associated with tooth sensitivity and a reduction in enamel microhardness.18-20 In general, complete remineralization of WSLs does not occur with topical applications of various products.21 Other treatment options for WSLs include microabrasion and restoration. Although microabrasion can remove WSLs, the technique has the potential to remove large amounts of enamel.16,22 Tooth preparations for traditional resin-based composite restorations, veneers and crowns require removal of enamel beyond the demineralized zone and may extend into dentin.23 Because orthodontic WSLs predominantly affect a young patient population, long-term prognosis of the restored teeth is a significant concern. Considering the invasiveness of microabrasion or traditional restorations compared with the relatively small amount of demineralized enamel in WSLs, a less invasive restorative technique would be preferable. Resin infiltration has been marketed as a minimally invasive restorative treatment option and involves penetration of a resin into the body of the WSL, with minimal loss of enamel.24 With this method, the clinician uses an acid etchant to remove the outer layer of sound remineralized enamel, exposing the demineralized lesion body; he or she subsequently fills the lesion with a low-viscosity resin.24 The results of in vitro studies have shown significant masking of WSLs with use of resin infiltration techniques.25-27 Initial in vivo case report findings have been promising, showing immediate significant improvement in the appearance of WSLs.28,29 Although clinicians have used resin infiltration for restoration of teeth with interproximal incipient caries, no ran domized clinical trials, to our knowledge, have been conducted to evaluate resin infiltration of WSLs.
The purpose of this randomized, singlemasked clinical trial was to assess the esthetic improvement and changes in the area of WSLs treated with resin infiltration. Patients who had developed WSLs during orthodontic therapy were treated with a commercially available resin infiltration system. We obtained photographs of WSLs before treatment (T1), immediately after treatment (T2) and eight weeks later (T3). Using the photographs, orthodontists rated changes in the appearance of the WSLs and measured changes in the WSL area. Our hypothesis was that WSLs in teeth restored with resin infiltration would have an improved appearance and a reduced area compared with untreated WSLs. METHODS
The institutional review board at the Oregon Health & Science University, Portland, approved this study. Power analysis, assuming an estimated 70 percent improvement in appearance on the basis of changes in WSLs treated with resin infiltration reported in a previous study,29 indicated that a minimum sample size of 20 patients was needed to show significance at a power of 80 percent. Allowing for a 30 percent dropout rate, we set an enrollment goal of 30 participants. We allocated patients according to Consolidated Standards of Reporting Trials (CONSORT) guidelines (Figure 1).30 To recruit participants from the orthodontic clinic of the Oregon Health & Science University, the lead investigator (S.V.S.) searched patient records consecutively and retrospectively from December 2011 to December 2007. Initial screening for inclusion was based on intraoral photographs obtained immediately after removal of orthodontic appliances that showed WSLs on at least two maxillary anterior teeth. Additional inclusion criteria included an absence of preexisting (before orthodontic treatment) white spots determined on the basis of pretreatment photographs, patient age in the range from 12 through 30 years, no previous treatment of WSLs, at least three months having elapsed since removal of orthodontic appliances, WSLs having an International Caries Detection and Assessment System (ICDAS)31 score of 2 (that is, distinct visual change in enamel opacity) or 3 (localized enamel breakdown due to caries with no visible ABBREVIATION KEY. CONSORT: Consolidated Standards of Reporting Trials. ICDAS: International Caries Detection and Assessment System. NA: Not applicable. VAS: Visual analog scale. WSL: Whitespot lesion.
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dentin) and absence of active caries. Assessed for eligibility (n = 1,227) As we identified potential participants through records Excluded (n = 1,197) Enrollment reviews, one of us ● Not meeting inclusion criteria (n = 1,118) ● Declined to participate (n = 79) (S.V.S.) contacted them by telephone; if they agreed to parRandomized (n = 30) ticipate in the study, an appointment Allocation was scheduled for a clinical examination and WSL treatment. Allocated to intervention (n = 30) During the clinical ● Received allocated intervention (n = 23) ● Did not receive allocated intervention (did examination, the not keep appointment) (n = 7) clinician (S.V.S.) confirmed the presence Teeth randomly allocated to of WSLs by using Follow-up intervention and nonintervention the ICDAS.31 Other groups information collected Lost to follow-up (did not keep appointment) (n = 3) from the patient’s Discontinued intervention (n = 0) record included sex, age, length of time Analysis in orthodontic appliances and time elapsed since removal Analyzed (n = 20) ● Excluded from analysis (n = 0) of the orthodontic appliances. For each participant, we used an electronic random Figure 1. Flow diagram, according to Consolidated Standards of Reporting Trials (CONSORT).30 number generator to select one affected tooth to serve as a control on each tooth in the treatment group for five (no treatment), and we assigned the remaining seconds by using a fine-grit polishing disk (EP teeth to the treatment group. Owing to reports Esthetic Polishing Kit, Brasseler, Savannah, of variable responses to treatment,27,28 allocation Ga.) in a slow-speed handpiece. The purpose of teeth was biased toward the treatment group of this step was to maximize the potential for to maximize the number of teeth treated. resin infiltration of long-standing WSLs. The Resin infiltration. The clinician (S.V.S. or clinician then placed a 15 percent hydrochloric another dentist) followed the resin infiltration acid gel (Icon Etch, DMG America) on the WSL (Icon Infiltrant, DMG America, Englewood, N.J.) for two minutes, being careful to avoid contact protocol in the manufacturer’s instructions, exwith gingival tissue, followed by a water rinse cept for the method of tooth isolation and use of and compressed air drying (each for 30 seconds). mild abrasion. Rather than using a rubber dam, The etch, rinse and dry steps were repeated, as directed in the instructions, he or she placed a after which the clinician desiccated the lesions dry-field isolation system (Nola, Great Lakes Orby using ethanol (Icon Dry, DMG America) and thodontics, Tonawanda, N.Y.) for unobstructed air dried them for 30 seconds. The practitioner access to enamel adjacent to gingival margins. applied the resin infiltrant (Icon Infiltrant) to The clinician cleaned the teeth in both groups the tooth surface and allowed it to penetrate the with a rubber cup and plain pumice (Integra lesion for three minutes. A cotton roll was used Miltex, York, Pa.), rinsed them for 30 seconds to wipe excess material from the surface, and and air dried them for 30 seconds; he or she then the material then was light cured (1,600 milobtained photographs (T1). liwatts/square centimeter) for 40 seconds. The On the basis of a discussion between the clinician again applied the resin infiltrant for lead investigator and a representative of DMG one minute, removed the excess and light cured America (Steve Richard, oral communication, the material for 40 seconds. Dental floss was May 5, 2012), the clinician abraded the WSL used to remove the excess resin from the proxiJADA 144(9) http://jada.ada.org September 2013 999 Copyright © 2013 American Dental Association. All Rights Reserved.
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mal spaces, and the clinician polished the facial surface by using a mildly abrasive polishing cup (Enhance, Dentsply, York, Pa.). After the infiltration treatment (T2), the clinician evaluated all teeth by recording the ICDAS score and noting any irregularity of the restoration; he or she then photographed the teeth. A staff member gave patients oral hygiene supplies (toothbrush, fluoride toothpaste and dental floss) and instructions for home care. At the patients’ follow-up visit eight weeks later (T3), the clinician isolated their anterior teeth; cleaned them with flour of pumice; and rinsed, air dried, evaluated and photographed them. Photographs and orthodontists’ evaluations of WSLs. The clinician obtained photographs of each tooth with WSLs at the three time points by using a digital camera (Nikon D60, Nikon, Tokyo) with a macro lens (100-mm Macro Rokkor-X, Minolta [now Konica Minolta], Tokyo) and a point-source flash positioned at a fixed focal distance from the patient. The clinician dried the tooth surfaces immediately before obtaining the images to prevent moisture from influencing the WSL’s appearance. One of us (A.V.) cropped the photographs of the teeth and placed them into slide presentation software. For each tooth, we showed the images to the raters side by side, with the T1 image on the left and the T2 or T3 image on the right. We randomly sequenced the slides, showing the image pairs among control and experimental teeth and among time points. Owing to the large number of comparisons (n = 152), we gave each rater one of two sequenced versions of the slides to mitigate potential systematic bias resulting from rater fatigue. Each sequence included 20 repeated image pairs to assess intrarater reliability. Five raters (J.J.C., D.A.C., and three other orthodontic faculty members) underwent technique calibration through a series of six slides. They then rated esthetic changes of the WSL for each tooth by marking a 100-millimeter visual analog scale (VAS); 0 indicated no improvement and 100 represented complete disappearance of the WSL. To quantify the ratings, an investigator (S.V.S.) measured the distance in millimeters from the 0 end of the VAS to the rater’s mark. WSL area calculation. The lead investigator encoded image file names to mask the time point of the image (that is, T1, T2 or T3). Another investigator (A.V.) outlined and measured WSL areas for each of the three time points by using an image analysis program (ImageJ, National Institutes of Health, Bethesda, Md.) that was calibrated from a photograph of a ruler obtained at the fixed focal distance. He used the
area (in square millimeters) of each tooth and corresponding WSL to calculate the percentage change in the WSL area by comparing the T1 image with the T2 image and the T1 image with the T3 image. To evaluate method error, the investigator repeated measurements of 20 teeth several days later. Statistical analysis. We averaged the VAS results from the five raters for each tooth and time point and analyzed them by using repeated-measures analysis of variance (ANOVA). We also analyzed the percentage change in the area of the WSL measurements by using repeated-measures ANOVA. In addition, we analyzed the factors of age, sex, time elapsed since appliance removal, treatment duration, tooth type and initial WSL severity by using repeated-measures ANOVA for the effect on the VAS rating and on the percentage change in area for teeth in the treatment group. We calculated interrater reliability for the VAS method by using Pearson correlation coefficients.32 We also used Pearson correlation coefficients to measure intrarater reliability for the VAS and for area calculation methods.32 We used the Dahlberg formula to calculate method error for area measurements.33 RESULTS
Enrollment. In February 2012, the lead investigator reviewed 1,227 patient records and identified 109 patients as meeting the inclusion criteria (Figure 1). When potential participants were contacted, 79 declined and 30 agreed to enroll. Subsequently, seven participants failed to keep their initial appointment (T1) and three failed to keep their posttreatment follow-up appointment (T3), resulting in a total of 20 participants completing the study. Among those who completed the study, a total of 66 teeth met the inclusion criteria; we allocated 46 of these teeth to the treatment group and 20 served as controls (no intervention). Although we did not time the procedure systematically, treating three teeth per patient required approximately 25 minutes. Clinical examination. The clinician observed a stippled surface texture, not expected before treatment, at T2 and T3 on most teeth restored with resin infiltration. He did not observe any other irregularities in resin infiltration restorations. We did not include ICDAS data in the final analysis owing to the low number of teeth (n = 4) having an ICDAS score of 3 at T1. All teeth in the treatment group that had an ICDAS score of 3 at T1 had an ICDAS score of 2 at T2 and T3.
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Orthodontists’ evaluations of WSLs. Teeth that underwent treatment (Figures 2 through 4) had significantly higher VAS ratings (Figure 5) than did control teeth. At T2, the mean VAS rating for teeth that received treatment was 67.7 compared with 5.2 for control teeth (P < .001) (Figure 5). At T3, the mean VAS rating for teeth that received treatment was 65.9 compared with 9.2 for control teeth (P < .001) (Figure 5). In both the treatment and control groups, we found no significant difference in VAS ratings when comparing changes at T2 with those at T3. The factors of age, sex, tooth type, time in orthodontic appliances, time elapsed since appliance removal and initial WSL severity did not have a significant effect on VAS ratings in treated teeth (Table). Pearson correlation coefficients were high for intrarater reliability, ranging from r = 0.97 to 0.99 for the five raters. The Pearson correlation coefficient for interrater reliability also was strong (r = 0.97) among the five raters. Standard deviations (SDs) for the VAS ratings were relatively wide at T2 (SD = 22.3) and T3 (SD = 26.6) for teeth treated with resin infiltration (Figures 5 and 6, page 1003). WSL area calculations. At T2, the mean percentage reduction in WSL area was 61.8 percent for teeth receiving treatment compared with -3.3 percent for control teeth (P < .001) (Figure 7, page 1003). Similarly, at T3, the mean percentage reduction was 60.9 percent for teeth receiving treatment compared with 1.0 percent for control teeth (P < .001) (Figure 7). The results showed no significant difference in percentage reduction between T2 and T3 in both the treatment and control groups. Standard deviations were relatively wide at T2 (SD = 23.9 percent) and at T3 (SD = 24.2 percent) for teeth treated with resin infiltration. Method error for area measurement was 0.47 mm2 relative to the initial WSL areas that ranged from 1.1 mm2 to 42.9 mm2. The factors of age, sex, time elapsed since appliance removal, treatment duration, tooth type and initial WSL severity did not have a significant effect on the percentage reduction in WSL area in treated teeth (Table). DISCUSSION
Although Davila and colleagues described resin infiltration as a restorative treatment for WSLs nearly 40 years ago, Kielbassa and colleagues24 proposed that advances in technique and materials have resulted in a more effective approach. Consistent with this assertion, the results of our study—in which we used VAS ratings of changes in WSL appearance and area 34
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Figure 2. Photographs depicting an above-average response to resin infiltration treatment. Left, tooth at T1 (before treatment). Right, tooth at T3 (eight weeks after treatment). Mean visual analog scale rating (on a 0-to-100–millimeter scale), 89; percentage reduction in area of the white-spot lesion, 81 percent.
Figure 3. Photographs depicting an average response to resin infiltration treatment. Left, tooth at T1 (before treatment). Right, tooth at T3 (eight weeks after treatment). Mean visual analog scale rating (on a 0-to-100–millimeter scale), 70; percentage reduction in area of the white-spot lesion, 58 percent.
Figure 4. Photographs depicting a below-average response to resin infiltration treatment. Left, tooth at T1 (before treatment). Right, tooth at T3 (eight weeks after treatment). Mean visual analog scale rating (on a 0-to-100–millimeter scale), 19; percentage reduction in area of the white-spot lesion, 23 percent.
measurements of the lesions—show that resin infiltration can predictably and significantly improve the esthetics of most teeth. Our results are similar to those reported by Kim and colleagues29 in a postorthodontic treatment case JADA 144(9) http://jada.ada.org September 2013 1001
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TABLE
Factors assessed for correlations with VAS* ratings and percentage reduction in WSL† area among treated teeth, T1‡ to T2 § . Factor
Standard deviation
Minimum
Maximum
P Value VAS
P Value PERCENTAGE reduction in WSL area
No. of patients or teeth
Mean
Age, in Years
20
16.6
1.8
14
21
.194
.391
Sex
20
NA ¶
NA
NA
NA
.906
.422
Time in Orthodontic Appliances, in months
20
32.5
8.4
21
48
.639
.592
Time Elapsed After Removal of Orthodontic Appliances, in Months
20
12.3
11.1
3
48
.177
.256
Tooth Type #
46
NA
NA
NA
NA
.155
.306
Severity (Percentage of Tooth Surface With WSLs at T1)
46
25.0
16.2
1.6
79.1
.283
.712
* VAS: Visual analog scale. † WSL: White-spot lesion. ‡ T1: Before treatment. § T2: Immediately after treatment. ¶ NA: Not applicable. # Central incisor, lateral incisor or canine.
standing, we also abraded all of them mildly for five seconds 90 before etching to enhance the effectiveness of the etchant 80 and subsequent infiltration 70 by reducing the superficial 60 layer of remineralized enamel. 50 (According to Wayne Flavin, 40 Director of Scientific Affairs, 30 DMG America, oral com20 munication, July 25, 2013, the abrasion step would not 10 be needed for newly formed 0 Control Treatment WSLs and, thus, more enamel would be preserved.) The GROUP variation in outcomes for teeth treated with resin infiltration T2 T3 may have been due to differences in lesion anatomy, with Figure 5. Mean (standard deviation) visual analog scale (VAS) ratings, according to group the thickness of the superficial and time. Treatment teeth exhibited statistically higher VAS ratings than did control teeth at T2 (immediately after treatment) and at T3 (eight weeks after treatment) (both P < remineralized layer likely be.001). Within the control teeth group and within the treatment teeth group, there was no ing the biggest factor.26 statistically significant difference in VAS ratings between T2 and T3. Researchers have reported series in which 17 of 18 WSLs treated with considerable variation in thickness of the reresin infiltration were partially or completely mineralized layer, with the majority of lesions masked. having a surface-layer thickness of between The resin infiltration method used in our 20 and 60 micrometers.35,36 Although we did study entailed minor modifications to the not measure the amount of enamel removed, manufacturer’s instructions. We used the Nola it is possible that teeth in the treatment group isolation system because use of a rubber dam, that achieved better outcomes underwent more as suggested by the manufacturer to prevent complete removal of this remineralized layer, moisture contamination and protect the ginwhereas those with little WSL improvement giva from the hydrochloric acid etchant, would may have undergone insufficient removal of have interfered with access to WSLs near the enamel. Measuring the amount of surface regingival margins. Because the WSLs were longmoved by the abrasion procedure and correlatVAS RATING
100
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PERCENTAGE CHANGE IN AREA
MEAN VAS RATING
ing this with the effectiveness of the resin infiltration treatment 100 ◆ ◆ ◆ ◆ ◆ ◆ ◆ should be a topic for future ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ 80 ◆ investigation. ◆ ◆ ◆ ◆ ◆ ◆ ◆ Measuring outcomes. We ◆ ◆ ◆ ◆ ◆ 60 ◆ ◆ designed the WSL evaluation ◆ ◆ ◆ ◆ ◆ ◆ method to provide a subjective ◆ ◆ 40 (VAS rating) and an objective ◆ ◆ ◆ ◆ (area measurement) approach for ◆ 20 ◆ ◆ measuring outcomes. Despite the ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ ◆ availability of technology-based 0 ◆ ◆ ◆ ◆ ◆ 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 methods for WSL evaluation (for example, quantitative light fluoPATIENT rescence), results of visual evaluations of photographs have been ◆ Treatment teeth ◆ Control teeth found to most closely match patients’ perceptions of esthetic conFigure 6. Mean visual analog scale (VAS) ratings at T3 (eight weeks after treatment) cerns.37 The main disadvantages for each tooth, according to patient. Note that treatment results for some patients of the WSL rating methods used were relatively consistent among teeth, whereas other patients experienced greater in this study relate to bias and variability. Most control teeth exhibited relatively minimal to no change in VAS ratings. lack of validity.37 We addressed these limitations by masking all 100 raters and by specifying inclu90 sion criteria that resulted in the 80 elimination of patients who had WSLs present before orthodontic 70 treatment or WSLs that had been 60 treated previously. The reliabil50 ity of the assessment methods 40 used was demonstrated by the relatively low method error (0.47 30 mm2) for the area measurements 20 and by strong intrarater (mean r 10 = 0.98) and interrater (r = 0.97) 0 reliability for the VAS ratings. The patient’s sex, age, time –10 Control Treatment in orthodontic appliances, time elapsed since appliance removal, GROUP tooth type and initial WSL severity had no statistically significant T2 T3 effect on outcomes for WSLs in teeth restored with resin infiltraFigure 7. Percentage change in area (in square millimeters) of the white-spot lesion tion. The insufficient improvefrom T1 (before treatment) to T2 (immediately after treatment) and from T1 to T3 ment in some teeth likely relates (eight weeks after treatment). Treated teeth exhibited a high percentage reduction to the methods used in this study, compared with control teeth at T2 and T3 (both P < .001). Comparisons within the control teeth group and the treated teeth group revealed no differences between T2 in particular the selection criand T3 measurements. teria. For example, we defined initial severity as the percentage of the tooth factors could account, in part, for the somewhat covered by WSLs at T1, and we did not take into high standard deviations found in our study and account other anatomical factors such as lesion present potential topics for future investigation. depth, a variable that could potentially influWith broadened selection criteria, it may be posence the results.26 Furthermore, it is known that sible to determine whether the patient’s age and enamel becomes less permeable with age38,39 and duration of the WSLs affect the results of resin that the remineralized surface layer thickness infiltration restoration. of WSLs may increase with time elapsed after Although WSLs often are unesthetic, the reremoval of orthodontic appliances, thus resultsults of previous studies have shown that they ing in improvements in oral hygiene.35 Such are stable in the long term and usually do not JADA 144(9) http://jada.ada.org September 2013 1003 Copyright © 2013 American Dental Association. All Rights Reserved.
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progress to caries.2,4 In this study, variations in assessment outcomes for control teeth at all time points were negligible. Among the treated teeth, clinical examinations at T2 and T3 revealed no open margins, ledges or wear. However, it is likely that, as with traditional anterior resin-based composites, the resin material may, over time, stain relative to adjacent enamel, thus compromising esthetics.40,41 Although the stippled surface texture that raters observed on close examination of the restorations could be viewed as a minor defect, we found that the texture could be removed easily at a later date with use of more aggressive polishing disks (data not shown). Investigators have found that with interproximal incipient carious lesions, the defects can be predictably infiltrated,24 the caries progression rate is reduced26 and placement of more invasive restorations can be delayed.42 Although the restored teeth in our study were stable over the eight-week period, long-term in vivo outcomes for resin infiltration restorations in teeth with WSLs have yet to be documented, to our knowledge. Effectiveness of resin infiltration. Results of this study are consistent with those of previous studies in which investigators showed that because resin infiltration is effective and relatively noninvasive, the approach has advantages over other options for the treatment of WSLs.24,36,42 High-concentration fluoride treatment has been contraindicated as this enhances remineralization of the superficial layer of the lesion, accelerating the arrest of remineralization in the subsurface portion of the WSL.43,44 Although microabrasion has been shown to reduce WSLs, resulting in 83 to 97 percent reductions in area, the procedure also removes up to 360 µm of the demineralized enamel.16,18,22,45 By comparison, the two rounds of etching with hydrochloric acid, as used in this study, have been shown to remove approximately 80 µm of affected enamel.35 Paris and colleagues46 demonstrated in vitro that resin infiltration can exceed a depth of 400 µm, making complete infiltration of deeper WSLs possible. Traditional resin-based composite restorations, veneers and crowns require removal of enamel, and matching natural tooth shade and opacity with those of the restoration can pose esthetic challenges, especially in the anterior region. The resin used in this study (Icon Infiltrant) is unfilled and has optical properties similar to those of natural enamel, effectively transmitting the natural shade of the tooth.25 Thus, if resin infiltration is shown to be stable in the long term, it may prove to be the treatment of choice for WSLs that fail to regress naturally.
CONCLUSIONS
The results of our study show that resin infiltration significantly improved the clinical appearance of WSLs and reduced their size. In addition, the clinical appearance of teeth with WSLs restored with resin infiltration was stable over the eight-week study period. n Disclosure. None of the authors reported any disclosures. This project was funded by the Oregon Health & Science University Foundation, Orthodontic Support Fund, Portland. The authors thank DMG America, Englewood, N.J., for donating the resin infiltrant (Icon Infiltrant), Rachel Yamakawa, DDS, for help with placing the restorations and Amy Trevor, DMD, and Will Marra (dental student) for their assistance in managing patients’ records and study records. 1. Geiger AM, Gorelick L, Gwinnett AJ, Benson BJ. Reducing white-spot lesions in orthodontic populations with fluoride rinsing. Am J Orthod Dentofacial Orthop 1992;101(5):403-407. 2. Øgaard B, Rølla G, Arends J, ten Cate J. Orthodontic appliances and enamel demineralization, part 2: prevention and treatment of lesions. Am J Orthod Dentofacial Orthop 1988;94(2):123-128. 3. Boersma J, Van der Veen M, Lagerweij M, Bokhout B, PrahlAndersen B. Caries prevalence measured with QLF after treatment with fixed orthodontic appliances: influencing factors. Caries Res 2005;39(1):41-47. 4. Gorelick L, Geiger AM, Gwinnett AJ. Incidence of white-spot formation after bonding and banding. Am J Orthod 1982;81(2):93-98. 5. Richter AE, Arruda AO, Peters MC, Sohn W. Incidence of caries lesions among patients treated with comprehensive orthodontics. Am J Orthod Dentofacial Orthop 2011;139(5):657-664. 6. Chang H, Walsh L, Freer T. Enamel demineralization during orthodontic treatment: aetiology and prevention. Aust Dent J 1997;42(5):322-327. 7. García-Godoy F, Hicks MJ. Maintaining the integrity of the enamel surface: the role of dental biofilm, saliva and preventive agents in enamel demineralization and remineralization. JADA 2008;139(suppl 2):25S-34S. 8. Øgaard B. White-spot lesions during orthodontic treatment: mechanisms and fluoride preventive aspects. Semin Orthod 2008; 14(3):183-193. 9. Benson P, Shah A, Millett D, Dyer F, Parkin N, Vine R. Fluorides, orthodontics and demineralization: a systematic review. J Orthod 2005;32(2):102-114. 10. Årtun J, Brobakken BO. Prevalence of carious white-spots after orthodontic treatment with multibonded appliances. Eur J Orthod 1986;8(4):229-234. 11. Øgaard B. Prevalence of white-spot lesions in 19-year-olds: a study on untreated and orthodontically treated persons 5 years after treatment. Am J Orthod Dentofacial Orthop 1989;96(5):423-427. 12. AI-Khateeb S, Forsberg CM, de Josselin de Jong E, AngmarMånsson B. A longitudinal laser fluorescence study of white-spot lesions in orthodontic patients. Am J Orthod Dentofacial Orthop 1998;113(6):595-602. 13. Bailey D, Adams G, Tsao C, et al. Regression of post-orthodontic lesions by a remineralizing cream. J Dent Res 2009;88(12):1148-1153. 14. Bishara SE, Ostby AW. White-spot lesions: formation, prevention, and treatment. Semin Orthod 2008;14(3):174-182. 15. Beerens MW, van der Veen MH, van Beek H, ten Cate JM. Effects of casein phosphopeptide amorphous calcium fluoride phosphate paste on white-spot lesions and dental plaque after orthodontic treatment: a 3-month follow-up. Eur J Oral Sci 2010;118(6):610-617. 16. Akin M, Basciftci FA. Can white-spot lesions be treated effectively? Angle Orthod 2012;82(5):770-775. 17. Huang GJ, Roloff-Chiang B, Mills BE, et al. Effectiveness of MI Paste Plus and PreviDent fluoride varnish for treatment of whitespot lesions: a randomized controlled trial. Am J Orthod Dentofacial Orthop 2013;143(1):31-41. 18. Basting RT, Rodrigues AL Jr, Serra MC. The effects of seven carbamide peroxide bleaching agents on enamel microhardness over time. JADA 2003;134(10):1335-1342. 19. Haywood VB, Leonard RH, Nelson CF, Brunson WD. Effective-
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