Enamel demineralization during orthodontic treatment. Aetiology and prevention

Assessment of White Spot Lesions and In-Vivo Evaluation of the Effect of CPP-ACP on White Spot Lesions in Permanent Molars of Children

INTRODUCTION

As hindrance of remineralisation process occurs during orthodontic therapy resulting in decalcification of enamel because number of plaque retention sites increases due to banding and bonding of appliances to teeth.

AIM

The present analytic study was undertaken to assess the occurrence of white spot lesions in permanent molars of children with and without orthodontic therapy and to evaluate the effect of Casein PhosphoPeptide-Amorphous Calcium Phosphate (CPP-ACP) on white spot lesions in post-orthodontic patients in a given period of time.

MATERIALS AND METHODS

The study comprised of examination of 679 first permanent molars which were examined to assess the occurrence of smooth surface white spot lesions in children of 8 to 16 years age group. Group I comprised subjects without any orthodontic treatment and Group II comprised of subjects who had undergone orthodontic therapy. The sample size was calculated using the epi-info6 computer package. Treatment group included 20 post-orthodontic patients examined with at least one white spot lesion within the enamel who received remineralizing cream (GC Tooth Mousse, Recaldent, GC Corporation.) i.e., CPP-ACP cream two times a day for 12 consecutive weeks. Computerized image analysis method was taken to evaluate white spot lesions. These frequency and percentages were compared with chi-square test. For comparison of numeric data, paired t-test was used.

RESULTS

Of the total 278 (49.6%) first permanent molars showed occurrence of smooth surface white spot lesions out of 560 in Group I and 107 (89.9%) first permanent molars showed presence of white spot lesions out of 119 debanded first permanent molars of children examined in Group II. CPP-ACP therapy group showed reduction in severity of codes which was found to be highly significant after 12 weeks and eight weeks on gingival-third, p-value (<0.001) and significant after eight weeks and four weeks on middle-third according to ICDAS II criteria and computerized image analysis.

CONCLUSION

CPP-ACP therapy minimum for 12 weeks is highly recommended as post-orthodontic treatment need in management of smooth surface white spot lesions on teeth undergoing fixed orthodontic therapy according to the present study.

A practice-based evaluation of the prevalence and predisposing etiology of white spot lesions

OBJECTIVE

To use an alumni-centered, practice-based research network to evaluate white spot lesions (WSLs) among treated orthodontic patients.

MATERIALS AND METHODS

An initial survey was conducted to ascertain whether orthodontic alumni from Texas A&M University Baylor College of Dentistry were willing to participate. Twenty randomly selected alumni participated, providing 158 treated cases. Each alumnus (1) obtained internal review board consent; (2) submitted pre- and posttreatment photographs of 10 consecutively finished cases; (3) completed a treatment survey; and (4) had the patient/parent complete the American Dental Association (ADA) Caries Risk Assessment.

RESULTS

Almost 90% of the alumni surveyed were willing to participate in the practice-based research, primarily because a fellow alumnus asked them to. Approximately 28% of the patients developed WSLs. The average patient developed 2.4 white spots, affecting 12.7% of the teeth examined. WSLs were significantly (P < .001) more (2.3-3.2 times) likely for patients who were identified on the ADA Caries Risk Assessment. The risk of developing WSLs during treatment was also increased for those with fair (2.7 times) or poor (3.5 times) oral hygiene, poor gingival health (2.3 times), and extended treatment times (2.1 times).

CONCLUSIONS

There is a substantial risk of developing WSLs among private practice patients, depending partially on the length of treatment. Patients at greatest risk can be identified prior to treatment based on the ADA Caries Risk Assessment, oral hygiene, and gingival health.

Lingual vs. labial fixed orthodontic appliances: systematic review and meta-analysis of treatment effects

The aim of this systematic review was to compare the therapeutic and adverse effects of lingual and labial orthodontic fixed appliances from clinical trials on human patients in an evidence-based manner. Randomized and prospective non-randomized clinical trials comparing lingual and labial appliances were included. Risk of bias within and across studies was assessed using the Cochrane tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Random-effects meta-analyses were conducted, followed by subgroup and sensitivity analyses. Six electronic databases were searched from inception to July 2015, without limitations. A total of 13 papers pertaining to 11 clinical trials were included with a total of 407 (34% male/66% female) patients. Compared with labial appliances, lingual appliances were associated with increased overall oral discomfort, increased speech impediment (measured using auditory analysis), worse speech performance assessed by laypersons, increased eating difficulty, and decreased intermolar width. On the other hand, lingual appliances were associated with increased intercanine width and significantly decreased anchorage loss of the maxillary first molar during space closure. Based on existing trials, there is insufficient evidence to make robust recommendations for lingual fixed orthodontic appliances regarding their therapeutic or adverse effects, as the quality of evidence was low.

The effect of fixed appliances on oral malodor from beginning of treatment till 1 year

BACKGROUND

Orthodontic appliances can enhance plaque accumulation, and this can cause gingival inflammation. Halitosis of oral origin is associated with microbial metabolism on the tongue and in the saliva, dental plaque, and the amount of volatile sulfide-containing compounds. This study used a Halimeter to investigate fixed orthodontic therapy-associated increases in the oral malodor over a year.

METHODS

Thirteen orthodontic patients with Angle Class I malocclusions receiving fixed orthodontic therapy formed the study group, and 12 dental students without any dental treatment formed the control group. The Halimeter was used to examine oral malodor by detecting volatile sulfur compounds (VSC). Plaque index (PI), gingival index (GI), and probing pocket depth (PPD) were also measured in both groups. The subjects in the study group had one visit before the orthodontic treatment started and seven visits during orthodontic therapy (1, 3, 5, 7, 9, 11, and 13 months after bonding), while the subjects in the control group had three visits, once per subsequent month.

RESULTS

Oral malodor was significantly increased in the fixed orthodontic treatment group during treatment (p < .05). Increases were also observed in the PI, GI, and PPD measures (p < .05). The results of the control group were stable (p > .05).

CONCLUSION

Oral malodor increased during fixed orthodontic treatments and reached a critical level 7 months later.

Effectiveness of fluoride sealant in the prevention of carious lesions around orthodontic brackets: an OCT evaluation

Objective:

This article aimed to evaluate in vitro the efficiency of Pro Seal fluoride sealant application in the prevention of white spot lesions around orthodontic brackets.

Material and Methods:

Brackets were bonded to the buccal surface of bovine incisors, and five groups were formed (n = 15) according to the exposure of teeth to oral hygiene substances and the application of enamel sealant: G1 (control), only brushing was performed with 1.450 ppm fluoride; G2 (control) brushing associated with the use of mouthwash with 225 ppm fluoride; G3, only Pro Seal sealant application was performed with 1.000 ppm fluoride; G4 Pro Seal associated with brushing; G5 Pro Seal associated with brushing and mouthwash. Experimental groups alternated between pH cycling and the procedures described. All specimens were kept at a temperature of 37 °C throughout the entire experiment. Both brushing and immersion in solutions were performed within a time interval of one minute, followed by washing in deionized water three times a day for 28 days. Afterwards, an evaluation by Optical Coherence Tomography (OCT) of the spectral type was performed. In each group, a scanning exam of the white spot lesion area (around the sites where brackets were bonded) and depth measurement of carious lesions were performed. Analysis of variance (ANOVA) was applied to determine whether there were significant differences among groups. For post hoc analysis, Tukey test was used.

Results:

There was statistically significant difference between groups 1 and 2 (p = 0.003), 1 and 3 (p = 0.008), 1 and 4 (p = 0.000) and 1 and 5 (p = 0.000). The group in which only brushing was performed (Group 1) showed deeper enamel lesion.

Conclusion:

Pro Seal sealant alone or combined with brushing and/or brushing and the use of a mouthwash with fluoride was more effective in protecting enamel, in comparison to brushing alone.

Minimally invasive resin infiltration of arrested white-spot lesions: a randomized clinical trial

BACKGROUND

The authors conducted a randomized, single-masked clinical trial involving patients who had completed orthodontic treatment to assess changes in the 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 demonstrated 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.

An assessment of preventive care offered to orthodontic patients by oral health therapists in NSW Australia

OBJECTIVE

The aim of this study was to record preventive oral health care planned by dental therapists and oral health therapists (therapists) for patients with poor oral hygiene undergoing orthodontic treatment.

MATERIALS AND METHODS

A cross-sectional survey, using a clinical vignette of a patient with poor oral hygiene undergoing therapy with a fixed appliance, was undertaken to record the preventive care offered to this individual by therapists working across 15 Local Health Districts (LHDs). This orthodontic vignette was inserted between two dental caries-related vignettes. Data were coded and descriptive statistics were used to report the findings.

RESULTS

One-hundred and seventeen therapists returned questionnaires (giving a response rate of 64.6%), of whom 82.0% (n = 95) completed the orthodontic vignette. Adopting motivational interviewing techniques to facilitate communication with the patient and their parent was recommended by 88.4% (n = 84) respondents, 98.0% (n = 93) offered oral-hygiene instruction, 70.5% (n = 67) recorded plaque levels and used disclosing solution and 60.0% (n = 57) offered dietary advice. Products recommended for use at home included fluoride toothpaste [1,450 ppm F (80.0%; n = 76) and 5,000 ppm F (59.0%; n = 24)] and casein phosphopeptide amorphous phosphates plus fluoride (CPP-ACPF) paste (33.3%; n = 32). Less than 20% offered fissure sealants.

CONCLUSION

Preventive advice and care was offered inconsistently by therapists in this study. To ensure that all therapists adopt a scientifically based approach to prevention, LHD clinical directors should implement continuous professional education programmes for therapists to improve patient's health outcomes.

Effects of long-term repeated topical fluoride applications and adhesion promoter on shear bond strengths of orthodontic brackets

Objective:

The purpose of this study was to assess the effects of long-term repeated topical application of fluoride before bonding and an adhesion promoter on the bond strength of orthodontic brackets.

Materials and Methods:

A total of 76 bovine incisors were collected and divided equally into four groups. In group 1, the brackets were bonded without topical fluoride application or adhesion promoter. In group 2, before bonding, the adhesion promoter was applied to nonfluoridated enamel. In group 3, the brackets were bonded without the application of the adhesion promoter to enamel, which had undergone long-term repeated topical fluoride treatments. Teeth in group 4 received the long-term repeated topical applications of fluoride, and the brackets were bonded using the adhesion promoter. All the brackets were bonded using BeautyOrtho Bond self-etching adhesive. The shear bond strength was measured and the bond failure modes were evaluated with the use of the adhesive remnant index (ARI) after debonding.

Results:

The mean shear bond strength was significantly lower in group 3 than in groups 1, 2, and 4, and there were no significant differences between the groups except for group 3. There were significant differences in the distribution of ARI scores between groups 2 and 3, and between groups 3 and 4.

Conclusions:

The adhesion promoter can recover the bond strength reduced by the long-term repeated topical applications of fluoride to the prefluoridation level and had a significantly great amount of adhesives left on either fluoridated or nonfluoridated enamel.

Effect of enamel protective agents on shear bond strength of orthodontic brackets

BACKGROUND

This paper aimed to study the effect of two enamel protective agents on the shear bond strength (SBS) of orthodontic brackets bonded with conventional and self-etching primer (SEP) adhesive systems.

METHODS

The two protective agents used were resin infiltrate (ICON) and Clinpro; the two adhesive systems used were self-etching primer system (Transbond Plus Self Etching Primer + Transbond XT adhesive) and a conventional adhesive system (37% phosphoric acid etch + Transbond XT primer + Transbond XT adhesive ). Sixty premolars divided into three major groups and six subgroups were included. The shear bond strength was tested 72 h after bracket bonding. Adhesive remnant index scores (ARI) were assessed. Statistical analysis consisted of a one-way ANOVA for the SBS and Kruskal-Wallis test followed by Mann-Whitney test for the ARI scores.

RESULTS

In the control group, the mean SBS when using the conventional adhesive was 21.1 ± 7.5 MPa while when using SEP was 20.2 ± 4.0 MPa. When ICON was used with the conventional adhesive system, the SBS was 20.2 ± 5.6 MPa while with SEP was 17.6 ± 4.1 MPa. When Clinpro was used with the conventional adhesive system, the SBS was 24.3 ± 7.6 MPa while with SEP was 11.2 ± 3.5 MPa. Significant differences in the shear bond strength of the different groups (P = .000) was found as well as in the ARI scores distribution (P = .000).

CONCLUSION

The type of the adhesive system used to bond the orthodontic brackets, either conventional or self-etching primer, influenced the SBS, while the enamel protective material influenced the adhesive remnant on the enamel surface after debonding.

Factors Affecting the Formation, Severity and Location of White Spot Lesions during Orthodontic Treatment with Fixed Appliances

OBJECTIVES

The purpose of the present study was to investigate factors affecting the formation, severity and location of white spot lesions in patients completing fixed appliance therapy.

MATERIAL AND METHODS

A total of 45 patients (19 males and 26 females, mean age 15.81 years, standard deviation 2.89 years) attending consecutively Aberdeen Dental Hospital (ADH) between January and June 2013 to have their fixed appliances removed were given a questionnaire to elicit information regarding their dental care and diet. They were then examined clinically as well as their pre-treatment photographs to record treatment data and white spot lesion (WSL) location and severity using a modified version of Universal Visual Scale for Smooth Surfaces (UniViSS Smooth). Absolute risk (AR) and risk ratios (RR) were also calculated.

RESULTS

The incidence of at least one WSL observed in patients was 42%, with males displaying a higher incidence than females. The highest incidence of WSLs was recorded on the maxillary canines and lateral incisors, and on the maxillary and mandibular premolars and first molars. The gingival areas of the maxillary and mandibular teeth were the most affected surfaces. Significant (P < 0.05) relationships were found between the presence of WSLs and the following factors: poor oral hygiene (OH), males, increased treatment length, lack of use of fluoride supplements, use of carbonated soft drinks and/or fruit juices and the use of sugary foods. Poor OH posed the highest risk of developing WSL (RR = 8.55).

CONCLUSIONS

42% of patients have developed white spot lesions during fixed appliance therapy. Various contributing risk factors were identified with the greatest risk posed by a poor oral hygiene.

Antibacterial efficacy of prophylactic ozone treatment on patients with fixed orthodontic appliances

OBJECTIVE

This study investigated the efficacy of ozone on microflora of patients with fixed orthodontic appliances.

MATERIALS AND METHODS

Ten subjects undergoing fixed appliance therapy were enrolled in the study. Before any application, two elastic ligatures were removed with the aid of a sterile probe from the premolar brackets on the upper right and lower left jaws for baseline bacteriological counts. Then ozone gas was applied for 180 s by running the device on prophylaxis mode with included mouth tray according to the manufacturer's recommendations on all brackets. After the ozone application, two other elastic ligatures were removed from the opposite sides of the mouth of the patients. One week after the application two more elastic samples, which were not changed in the previous session, were collected from the upper right and lower left premolar brackets. The elastic ligatures were immersed in transfer solutions and cultured to determine the Streptococcus mutans and Lactobacillus acidophilus. Statistical analysis of the data was obtained by paired Student's t-tests.

RESULTS

The ozone treatment reduced the S. mutans and L. acidophilus immediately after the application and these reductions were found to be statistically significant (p = 0.038 and p = 0.020). Both the S. mutans and L. acidophilus values increased by the 1-week period and the S. mutans values were significantly higher than the baseline values (p = 0.01).

CONCLUSION

It can be concluded that the ozone treatment may have an instantaneous lethal effect on S. mutans and L. acidophilus; however, within the limitations of this study, a long-term preventive effect could not be observed.

Changes in the oral environment after placement of lingual and labial orthodontic appliances

Background

This study compared the oral hygiene and caries risk of patients treated with labial and lingual orthodontic appliances throughout a prospective evaluation of the status of the oral environment before and after bracket placement.

Methods

A total of 20 orthodontic patients aged 19 to 23 years were included in the study and were divided into two groups: 10 patients wore Roth labial appliance (American Orthodontics, Sheboygan, WI, USA) and 10 patients wore STb lingual appliance (Ormco Corporation, Glendora, CA, USA). Plaque index (PI), gingival bleeding index (GBI), salivary flow rate, saliva buffer capacity, salivary pH, and Streptococcus mutans and Lactobacillus counts in saliva were determined at three time points: before orthodontic appliance placement (T0), 4 weeks after bonding (T1), and 8 weeks after bonding (T2). After appliance placement, all patients were periodically educated to the oral hygiene procedures. Wilcoxon rank and Mann-Whitney U tests were used to determine intragroup and intergroup differences as regards qualitative data. To compare quantitative data between the groups, chi-square and Fisher's exact tests were undertaken, while intragroup differences were tested with McNemar test. The level of statistical significance was set at p < 0.05.

Results

Statistical analysis of the data obtained revealed a statistically significant difference between the data of T0 and T1 and the data of T0 and T2 of the PI scores and between T0 and T2 of the GBI scores in the group treated with the lingual appliance. The GBI value increased significantly between T0 and T1 but decreased significantly between T1 and T2 (p < 0.01) in the group treated with labial appliance. S. mutans counts increased significantly between T0 and T2 in the saliva samples of patients treated with lingual appliance. No statistically significant differences were found between S. mutans and Lactobacillus counts at the three terms of saliva collection in patients treated with labial appliance. No statistically significant differences were found between the two groups at the three time points as regards the salivary flow rate and saliva buffer capacity.

Conclusions

Lingual and labial orthodontic appliances showed a different potential in modifying the investigated clinical parameters: patients wearing STb lingual orthodontic appliance had more plaque retention 4 and 8 weeks after bonding, while there were more gingival inflammation and more S. mutans counts 8 weeks after bonding. No differences were found between the two groups as regards the Lactobacillus counts, the salivary flow rate, and saliva buffer capacity.

Reducing white spot lesion incidence during fixed appliance therapy

Fixed orthodontic appliances are commonly used in contemporary orthodontic treatment and can be associated with the development of white spot lesions on the teeth. These lesions can be detrimental to both the aesthetics and health of the teeth so prevention is better than cure and patient selection is critical. This paper discusses predictors of development in addition to methods to help prevent white spot lesions during fixed appliance therapy. Recommendations for oral hygiene regimes during fixed orthodontic appliance treatment are given, the development of white spot lesions (WSLs) described and ways to predict their occurrence identified.

CLINICAL RELEVANCE

Most general dental practitioners will have patients who are considering orthodontic treatment or are wearing fixed orthodontic appliances and so are at increased risk of developing WSLs. It is therefore important they are aware of predictors and ways to prevent WSLs.

In vitro study of the antibacterial properties and microbial colonization susceptibility of four self-etching adhesives used in orthodontics

OBJECTIVES

1. To determine the in vitro antibacterial effectiveness of the orthodontic bonding Transbond XT (3M Unitek) and four self-etching adhesives with possible use in orthodontic bonding (Clearfil Protect Bond, CPB; Clearfil Self-etching Bond, CSB; Transbond Plus Self-Etching Primer, TSEP; iBond) against Streptococcus mutans and Lactobacillus gasseri in order to compare that capacity among the adhesives and with respect to Transbond XT; 2. To determine the bacterial adhesion capacity of the above mentioned microorganisms to the tested adhesives.

MATERIALS AND METHODS

The inhibitory effects of the adhesives against S. mutans and L. gasseri were examined using the agar diffusion method with Whatman No.1 5mm disks loaded with 15 μl of adhesive, UV polymerized, layered on previously inoculated BHI and MRS plates incubated microaerobically for 48 hours at 37 degree C. Data were analysed with Kruskal-Wallis (P < 0.05) and Mann-Whitney tests, applying the Bonferroni correction (P < 0.003). Bacterial adhesion was studied with scanning electron microscopy.

RESULTS

Only CPB and iBond produced a clear growth inhibition halo against S. mutans and L. gasseri (P < 0.0001). iBond was the only tested product to which the bacteria adhere profusely, particularly S. mutans.

CONCLUSIONS

CPB has shown antimicrobial properties in vitro, and, provided the limitations of an in vitro study, the use of this self-etching adhesive may contribute to reduce microbial decalcification, making the use of this self-etching adhesive an attractive option for bracket bonding.

Clinical color intensity of white spot lesions might be a better predictor of enamel demineralization depth than traditional clinical grading

INTRODUCTION

The aims of this study were to calculate the volume of white spot lesions by using microcomputed tomography and to determine which clinical attribute of the white spot lesion could better predict its volume: the clinically visible white spot lesion surface area or its color intensity.

METHODS

White spot lesions were induced in 8 patients in vivo on 23 healthy premolars destined for extraction during orthodontic treatment by using specially designed plaque-retaining orthodontic bands. After 7 weeks, the premolars were extracted. After extraction, the resulting white spot lesions were photographed and clinically graded. The teeth were analyzed with microcomputed tomography.

RESULTS

After 7 weeks, 70% of the teeth developed clinical white spot lesions. Clinically, the size of the lesions varied from minor to severe. Their volumes varied from 0 to 1.2931 mm(3). The traditional grades for white spot lesions correlated significantly with color intensity. A significant correlation was found between white spot lesion color intensity and lesion volume. This correlation was found to be better than that between the white spot lesion clinical score and lesion volume.

CONCLUSIONS

Our results indicate that white spot lesion color intensity might predict the depth of enamel demineralization as well as or better than traditional white spot lesion scoring. Therefore, the dentist could use this information when planning treatment for white spot lesions.

A novel biomimetic orthodontic bonding agent helps prevent white spot lesions adjacent to brackets

OBJECTIVE

To compare changes in enamel microhardness adjacent to orthodontic brackets after using bonding agents containing various compositions of bioactive glass compared to a traditional resin adhesive following a simulated caries challenge.

MATERIALS AND METHODS

Extracted human third molars (n  =  10 per group) had orthodontic brackets bonded using one of four novel bioactive glass (BAG)-containing orthodontic bonding agents (BAG-Bonds) or commercially available Transbond-XT. The four new adhesives contained BAG in varying percentages incorporated into a traditional resin monomer mixture. Teeth were cycled through low-pH demineralizing and physiologic-pH remineralizing solutions once each day over 14 days. Microhardness was measured on longitudinal sections of the teeth 100, 200, and 300 µm from the bracket edge and beneath the brackets, at depths of 25 to 200 µm from the enamel surface. Normalized hardness values were compared using three-way analysis of variance.

RESULTS

Significantly less reduction in enamel microhardness was found with the experimental adhesives at depths of 25 and 50 µm at all distances from the bracket edge. In all groups, there were no significant changes in enamel microhardness past 125-µm depth. Results varied with the different BAG-Bonds, with 81BAG-Bond showing the smallest decrease in enamel microhardness.

CONCLUSIONS

The BAG-Bonds tested in this study showed a reduction in the amount of superficial enamel softening surrounding orthodontic brackets compared to a traditional bonding agent. The results indicate that clinically, BAG-Bonds may aid in maintaining enamel surface hardness, therefore helping prevent white spot lesions adjacent to orthodontic brackets.

Ion release from a novel orthodontic resin bonding agent for the reduction and/or prevention of white spot lesions. An in vitro study

OBJECTIVE

To measure ion release from four sol-gel bioactive glass-containing orthodontic resin bonding agents (BAG-Bonds) following immersion into simulated body fluid (SBF) at pH values of 4 and 7.

MATERIALS AND METHODS

Four BAG-Bonds, two containing fluoride, were developed. Prepared in our laboratory, the BAG-Bonds were composed of a mixture of resin monomers and bioactive glasses (BAGs). Workability of the final BAG-Bonds determined the amount of filler added to each, and this varied according to BAG composition. Commercially available Transbond-XT was used as the control. Three disks (10 mm × 2 mm) of each material were individually suspended in 3.5 mL of SBF at pH 4 and pH 7. SBF was analyzed to measure pH and ions released at 1 hour, 10 hours, and 100 hours. Calcium was measured by atomic absorption analysis, phosphate by ultraviolet visible spectrometry, and fluoride by an ion-specific electrode. The data were compared using a three-way analysis of variance, with P ≤ .05.

RESULTS

Significant differences in calcium and phosphate ion release were found between the four BAG-Bonds and the control at multiple time points. Significant changes in pH were also found. There was no measureable release of fluoride from any of the materials.

CONCLUSIONS

The BAG-Bonds showed the capacity for buffering acidic oral environments and significant release of calcium ions into their surrounding environment, and they hold the potential to be biomimetic bonding agents that may reduce white spot lesion formation.

Determinants of enamel decalcification during simulated orthodontic treatment

OBJECTIVE

To determine the relative effects that phosphoric acid etching, metal brackets, composite resin adhesives, and filled resin sealants have on enamel decalcification.

MATERIALS AND METHODS

One hundred and fifty teeth were randomly divided into six groups to test the effects of acid etching, brackets, and a composite resin adhesive. The right side of each tooth was sealed. The teeth were submitted to a simulated carious challenge by Streptococcus mutans in a nutritive media for 42 days. Scanning electron photomicrographs (SEMs) were used to qualitatively evaluate the tooth surfaces. DIAGNOdent laser fluorescence was used to quantify the decalcification changes that occurred.

RESULTS

SEMs showed normal enamel on the control teeth, etching patterns on the acid-etched teeth, surface degradation on the teeth that had resin, and sealant tags on the sealed side. The untreated control group showed significantly less decalcification (P ≤ .05) than did all groups except the no etch+bracket group. The no etch+bracket group showed significantly less decalcification than did the etch+bracket, no etch+resin, and the etch+resin groups. Acid-etched teeth demonstrated significantly more decalcification (34%) than did those that were not etched. The teeth with resin showed significantly more decalcification (24%) than did those without resin. There was no significant difference between teeth that did and did not have brackets. The unsealed side of the teeth showed small amounts of--but significantly more--decalcification (5%) compared to the sealed side.

CONCLUSIONS

Acid etching and composite resin adhesives increase enamel decalcification in vitro, while brackets do not. Filled resin sealants protect the teeth from decalcification.

White-spot lesions during multibracket appliance treatment: A challenge for clinical excellence

INTRODUCTION

White-spot lesions (WSL) are one of the most undesired side effects of multibracket appliance treatment (MB). The aim of this study was to investigate the incidence and further course of WSL during and after MB.

METHODS

Four hundred patients (168 boys, 232 girls) meeting the inclusion criteria--all maxillary front teeth fully erupted and visible before treatment, no fillings or structural abnormalities, MB duration of at least 1 year, and retention period of at least 1 year--were selected. The patients' average age was 13.7 years (SD, 3.5), and the average MB time was 1.9 years (SD, 3.6). All patients received standardized general prophylactic instructions. A modification of the WSL index was used to evaluate the 4 maxillary front teeth on introral photos before and after treatment, and after retention.

RESULTS

Before treatment, 32.3% of the patients had WSL. After MB, 73.5% of the patients presented WSL. The incidence of WSL during MB was 60.9% of the patients. After treatment, most patients (63.3%) had mild lesions, but the remaining were affected severely with (26.9%) and without (9.9%) cavitations. Only 26% of the patients were free of WSL all the time. After the retention phase, most (57.1%) of the WSL patients after treatment showed improvement, 26% remained unchanged, and 16.7% deteriorated. Male WSL patients tended to show more severe WSL than did the girls. There was a tendency for increased WSL development during the adolescent years compared with the preadolescent and postadolescent age groups.

CONCLUSIONS

With only standardized general prophylactic measures, new WSL developing on the maxillary front teeth during MB remain a frequent undesired side effect, affecting 60.9% of patients and counteracting our efforts for clinical excellence.

A case of severe caries and demineralisation in a patient wearing an essix-type retainer

This case report presents a patient who developed significant caries and demineralisation due to consumption of large quantities of cariogenic drinks while he was wearing an Essix retainer. The risks to dental health during orthodontic retention and the responsibilities of general dental practitioners, orthodontists and patients are highlighted.

Excess adhesive flash upon bracket placement. A typodont study comparing APC PLUS and Transbond XT

OBJECTIVE

To determine if there is any significant difference in excess adhesive flash (EAF) with the use of APC PLUS adhesive coated appliance system and Transbond XT and if other variables such as side of the mouth, time taken to bond the brackets, the age of the orthodontic specialist, or the years of clinical experience affected the amount of EAF.

MATERIALS AND METHODS

Twenty orthodontic specialists bonded 20 preadjusted straight wire brackets (Victory, 3M Unitek) on a typodont with a Class I crowded malocclusion in a split-mouth design, with one-half of the brackets bonded with APC PLUS adhesive system and the other half with Transbond XT. The teeth were sputter coated with gold and an image was taken at 32x magnification in a scanning electron microscope (Philips XL30). The resultant tagged image file (TIF) was opened in AnalySIS Pro 3.1 (Soft Imaging System, Munich, Germany) and the area of EAF was measured.

RESULTS

t-Tests demonstrated that: (1) there was no statistically significant difference in EAF between two adhesives when bonding in different quadrants of dentition; and (2) there was no statistically significant difference in EAF between two adhesives overall. Analysis of variance models demonstrated there were no statistically significant differences found regarding the age of the orthodontic specialists, years of clinical experience, and time in performing the bonding.

CONCLUSIONS

The addition of a coloring agent to assist in the visualization of the excess adhesive does not reduce the amount of excessive adhesive around orthodontic brackets.

Caries preventive measures used in orthodontic practices: an evidence-based decision?

INTRODUCTION

Although it is well known that treatment with fixed appliances increases the risk of enamel demineralization, little information is available about preventive measures that orthodontists actually use. This study was executed to survey measures used in orthodontic practices to prevent decalcifications during fixed appliance treatment, and to compare these measures with the available evidence-based information.

METHODS

A questionnaire was sent to all privately practicing orthodontists in the Netherlands who were affiliated with the Dutch Dental Association.

RESULTS

Of 229 orthodontists, 178 (78%) returned the questionnaires. Most of the orthodontists had a basic practice protocol for preventing demineralizations at the start of treatment. This protocol nearly always included oral hygiene instructions. If demineralizations occurred, 99% of the orthodontists took extra measures. Comparing the measures applied in the orthodontic practices with the evidence from a systematic review, a number of differences became apparent. The additional use of chlorhexidine or toothpaste with a high fluoride concentration (which has been demonstrated to have an inhibitive effect) is rarely prescribed. Fluoride rinse is prescribed most often, although there is not any high-quality, long-term study that demonstrates a caries preventive effect in orthodontic patients. Sixty-eight percent of the orthodontists considered it necessary to develop a practice guideline for preventing demineralizations.

CONCLUSIONS

Orthodontists do not implement the available evidence in order to prevent enamel demineralizations during fixed-appliance treatment. A practice guideline incorporating this information should be developed.

Prevention of demineralization around orthodontic brackets in vitro

INTRODUCTION

The demineralization of enamel adjacent to orthodontic brackets is a significant clinical problem. The purpose of this in-vitro study was to investigate the effect of sodium fluoride (Colgate Neutrafluor 9000 ppm) (NaF) and 10% casein phosphopeptide-amorphous calcium phosphate (GC Tooth Mousse) (TM) on enamel demineralization adjacent to orthodontic brackets.

METHODS

Forty specimens were sectioned from the buccal or lingual surfaces of extracted sound third molars. Twenty specimens had molar tubes bonded with composite resin (Transbond XT, 3M, St Paul, Minn) (CR), and 20 were bonded with resin-modified glass ionomer cement (Fuji Ortho LC, GC America, Alsip, Ill) (RMGIC). A 2-mm window for enamel demineralization was prepared. The specimens were randomly divided into 4 treatment groups: control, TM, TM/NaF (50/50 w/w), and NaF. The treatment solutions were placed around the bracket margins, and the specimens were immersed inverted into a carbopol demineralization solution at 37 degrees C. The enamel specimens were exposed for 96 hours, with the demineralization and topical solutions changed every 4 hours. Quantitative light-induced fluorescence (QLF) images were taken every 8 hours under controlled conditions. The difference in fluorescence (DeltaF) and the proportional DeltaF (%F) change between baseline and 96 hours was calculated.

RESULTS

RMGIC significantly reduced DeltaF and %F when compared with CR (ANOVA, P = .029 and P = .034, respectively). Application of TM with CR, NaF with CR, and TM/NaF with CR significantly reduced DeltaF and %F compared with the control CR (Tukey post-hoc test, P <.001). Application of TM/NaF with RMGIC significantly reduced DeltaF and %F compared with the control RMGIC (Tukey post-hoc test, P = .008, P = .019, respectively).

CONCLUSIONS

With the limitations of any in-vitro study, the following clinical conclusions can be drawn. The use of RMGIC alone can significantly decrease enamel demineralization compared with CR. The application of TM/NaF can provide significant additional prevention of enamel demineralization when RMGIC is used for bonding. The application of TM, NaF, or TM/NaF can significantly prevent enamel demineralization when CR is used for bonding. The use of both agents should be recommended for any at-risk orthodontic patient to provide preventive actions and potentially remineralize early (subclinical) enamel demineralization.

Influence of bracket design on microbial and periodontal parameters in vivo

AIM

To compare undisturbed plaque formation on teeth bonded with different types of orthodontic brackets with non-bonded control teeth, via a de novo plaque growth experiment over a 7-day period.

MATERIAL AND METHODS

A randomized controlled trial with split-mouth design was set up enroling 16 dental students. Within each subject sites with Speed(S) and GAC(G), brackets and control sites were followed. Clinical periodontal parameters were recorded at baseline, on days 3 and 7. Microbiological samples were taken from the brackets and the teeth on days 3 and 7.

RESULTS

Both anaerobe and aerobe colony-forming units (CFU) were significantly higher in S-sites than in G-sites (p=0.0002, p=0.02). The shift from aerobic to anaerobic species was observed earlier in S-sites than in G-sites. The aerobe/anaerobe CFU ratio was significantly lower in S-sites than in G-sites (p=0.01). On day 3, the crevicular fluid flow was significantly higher in S-sites than in control sites (p=0.01). On day 7, S-sites and G-sites showed a significantly higher crevicular flow than control sites (both p<0.0001). More hypertrophy was seen in S- than in G- and control sites (p=0.05). No significant differences for bleeding on probing were observed.

CONCLUSION

Bracket design can have a significant impact on bacterial load and on periodontal parameters.

Prevention of white spot lesions in orthodontic practice: a contemporary review

The development of white spot demineralization associated with fixed appliance orthodontic treatment is a significant clinical problem. Both established and experimental methods for prevention of such lesions in day-to-day clinical practice are presented and discussed.

Orthodontics. Part 6: Risks in orthodontic treatment

Orthodontics has the potential to cause significant damage to hard and soft tissues. The most important aspect of orthodontic care is to have an extremely high standard of oral hygiene before and during orthodontic treatment. It is also essential that any carious lesions are dealt with before any active treatment starts. Root resorption is a common complication during orthodontic treatment but there is some evidence that once appliances are removed this resorption stops. Some of the risk pointers for root resorption are summarised. Soft tissue damage includes that caused by archwires but also the more harrowing potential for headgears to cause damage to eyes. It is essential that adequate safety measures are included with this type of treatment.

Evaluation of a reproduction technique for the study of the enamel composite/bracket base area

The objective of the study was to evaluate a reproduction method that would enable the study of the enamel/ bracket/composite interface in vivo, and consisted of in vitro assessment of two different impression materials to compare reproduction of brackets bonded to extracted teeth followed by in vivo assessment of the superior material. In vitro standard edgewise brackets were bonded to two extracted teeth and impressions were taken using two different types of low viscosity silicone-based impression materials. A medium viscosity silicone impression material was used to support the original impression. Three impressions of both the gingival and occlusal aspect of the bracket base region were obtained using each of the impression materials. Replicas were then prepared for SEM viewing and these compared to SEMs of the real teeth for reproduction of detail. A 3-point Reproducibility Index was used to compare the SEM photographs of the comparable replicas. One impression material was clearly superior to the other and produced an acceptably accurate representation of the true clinical situation in three out of four samples. This material also performed well in the in vivo situation. The technique described is satisfactory for the production and analysis of SEM pictures of the enamel/composite/ bracket base interface in vivo.

Preventive dentistry for the general dental practitioner

Although the prevalence of dental caries has decreased gradually in the past three decades in the Australian population, dental caries remains the primary reason for tooth loss in Australia. At the community level, total health expenditure on the treatment of dental caries (and its consequences) is substantial. Accordingly, caries prevention is an important focus at both the individual and community levels. This paper outlines the principles upon which modern caries prevention is based and stresses the importance of manipulating the oral environment (in terms of salivary parameters, ions, pH and the oral flora) as a major strategy for effective long-term caries prevention. Practical advice is provided on the correct home use of preventive agents, including chewing gums, chlorhexidine, fluorides, bicarbonate rinses and phosphopeptides.