Some "sealants" seal--a scanning electron microscopy (SEM) investigation

Orthodontists' instructions for oral hygiene in patients with removable and fixed orthodontic appliances

INTRODUCTION

The aim of this questionnaire-based survey was to evaluate information on frequencies, instructions and products relating to oral hygiene (OH) in orthodontic practices.

METHODS

Using a computer-generated randomization list, 1000 orthodontists were selected and sent a questionnaire. The size and number of inhabitants of the federal states of Germany were considered. The federal states with the highest return rate (Baden-Wuerttemberg [BW], Bavaria [B], Hesse [H], Lower Saxony [LS], Nordrhein-Westphalia [NRW]) were considered and differences between the 16 federal states were divided into North, South, East and Central Germany.

RESULTS

The response rate of the questionnaires was 52.4%. The majority (53.8%) worked in one practice alone. Most (59.1%) have been orthodontists for 5-25 years. For vestibular multibracket appliances (MBA) in BW, B, H and LS over 90% recommended interdental brushes (IDB). In NRW 91.4% recommend fluoride gel. In B and H more than 80% chose electric toothbrush (ETB), in BW, LS and NRW more than 80% manual toothbrush (MTB). For lingual MBA (LMBA) in BW, H, LS and NRW with approximately 50% each fluoride gel, IDB and MTB were chosen. In B fluoride gel, IDB and ETB. For removable apparatus (RA), five federal states recommended MTB (>80%) and ETB (BW, B, H > 80%; NRW > 70%; LS > 60%).

CONCLUSION

Electric toothbrushes are recommended for the use with all appliances, only with removable appliances manual toothbrushes are favoured. For vestibular MBA it is strongly advised to use IDB additionally.

Comparison of two methods of visual magnification for removal of adhesive flash during bracket placement using two types of orthodontic bonding agents

Objective:

This study aimed to evaluate the effectiveness of two methods of visual magnification (operating microscope and light head magnifying glass) for removal of composite flash around orthodontic metal brackets.

Material and Methods:

Brackets were bonded in the center of the clinical crown of sixty well-preserved human premolars. Half of the sample was bonded with conventional Transbond XT (3M Unitek TM, USA), whereas the other half was bonded with Transbond TM Plus Color Change (3M Unitek TM, USA). For each type of composite, the choice of method to remove the flash was determined by randomly distributing the teeth into the following subgroups: A (removal by naked eye, n = 10), B (removal with the aid of light head magnifying glass, under 4x magnification, n = 10), and C (removal with the aid of an operating microscope, under 40x magnification, n = 10). Brackets were debonded and teeth taken to a scanning electron microscope (SS-x-550, Shimadzu, Japan) for visualization of their buccal surface. Quantification of composite flash was performed with Image Pro Plus software, and values were compared by Kruskal-Wallis test and Dunn’s post-hoc test at 5% significance level.

Results:

Removal of pigmented orthodontic adhesive with the aid of light head magnifying glass proved, in general, to be advantageous in comparison to all other methods.

Conclusion:

There was no advantage in using Transbond TM Plus Color Change alone. Further studies are necessary to draw a more definitive conclusion in regards to the benefits of using an operating microscope.

Efficacy of light-activated sealant on enamel demineralization in orthodontic patients: an atomic force microscope evaluation

OBJECTIVE

The purpose of this study was to investigate the efficacy of (Pro Seal) sealant in preventing enamel decalcification in-vivo and compare its effect with fluoride varnish and unfilled sealant using atomic force microscopy.

MATERIALS AND METHODS

Eight orthodontic patients who were candidates for extraction of all first premolars for orthodontic treatment were recruited to this study. Thirty two premolars (upper and lower) were randomly divided into four groups (n=8) for each group, 4 maxillary and 4 mandibular); Control (no -treatment); Fluoride varnish, Unfilled sealant (Light Bond) and filled sealant (Pro-Seal). After two months the brackets were debonded and the teeth were extracted and prepared for Atomic force microscopic scanning. Each sample was scanned twice at two different scan areas 50 and 10µm at the buccal cervical third of the crown. Images were recorded with slow scan rate and resolution and the mean roughness height and total surface area were calculated for each scan area. Comparison between groups was performed using one way analysis of variance test with level of significance was set to be 0.05.

RESULTS

Pro Seal treated samples show the lowest roughness height and total surface area.

CONCLUSION

Pro Seal was the most effective prophylaxis technique in preventing enamel demineralization during orthodontic treatment.

Effects of sealant and self-etching primer on enamel decalcification. Part I: an in-vitro study

INTRODUCTION

The objective of this study was to compare the resistance to enamel demineralization between self-etching primer (SEP) and conventional sealant in vitro.

METHODS

A total of 120 molar sections were randomly assigned to 3 groups: SEP (Transbond Plus, 3M Unitek, Monrovia, Calif), sealant (Light Bond fluoride-releasing sealant, Reliance Orthodontic Products, Itasca, Ill), or control (no enamel treatment). SEP or sealant was applied following the manufacturer's recommendations. The tooth samples were exposed to rotary brushing for 2 minutes. A 2 x 2-mm window of sound enamel was created by using nail varnish. After 48 or 72 hours of acidic challenge with Ten Cate solution (pH 4.46), the samples were sectioned down to a thickness of 200 microm and stained with rhodomine B dye to evaluate lesions, lesion depths, area of lesions, and total fluorescence by using confocal microscopy. Statistical analyses were performed with 1-way analysis of variance (ANOVA) and Tukey-Kramer tests.

RESULTS

The incidence of lesion was 50% in the sealant group and 100% in both the SEP and the control group. The lesion in the sealant group was present only when the sealant integrity was broken. Lesion depth (149.9 +/- 20.5 microm), area (636 +/- 90 x 10(2) microm(2)), and total fluorescence (252 +/- 83 x 10(4)) in the SEP group were similar to those in the controls. Lesion depth (107.6 +/- 45 microm), area (441 +/- 212 x 10(2) microm(2)), and fluorescence (160 +/- 103 x 10(4)) in the sealant group were significantly less than in the SEP and control groups (P <0.05).

CONCLUSIONS

These results suggest that neither sealant completely protects the teeth against enamel decalcification. The application of sealant provided protection in 50% of the samples, whereas the SEP provided no resistance to enamel demineralization. Protection from acid demineralization depends on the integrity of the sealant.

Effect of light-cured filled sealant on the bond failure rate of orthodontic brackets in vivo

INTRODUCTION

The purpose of this study was to evaluate the effect of a highly filled light-cured sealant (HFLCS) on the bond failure rate of metal brackets bonded with a conventional composite adhesive in vivo for 18 months.

METHODS

In 30 consecutively treated patients, the teeth were divided into 2 groups based on the universal numbering system (1-32). Metal brackets were bonded to all odd-numbered teeth (n = 272) with a conventional composite resin; they served as the controls. Metal brackets were also bonded to all even-numbered teeth with the same composite resin but with a different sealant: HFLCS (Pro Seal, Reliance Orthodontic Products, Itasca, Ill). A total of 544 teeth were bonded and followed for 18 months. The difference between the failure rates (expressed as percentages) was compared with the McNemar test.

RESULTS

In the control teeth, the bond failure rate was 3.7%, and the mean failure time was 149 days. The teeth pretreated with Pro Seal had a bond failure rate of 2.9% and a mean bracket failure time of 127 days. Comparison of the bond failure rates did not show statistical significance (P = 0.81).

CONCLUSIONS

HFLCS did not adversely affect the failure rate and time of metal brackets when it was used instead of conventional sealant in a composite resin bonding system.

Prevention of enamel demineralization: An in-vitro study using light-cured filled sealant

INTRODUCTION

Enamel demineralization is an undesirable side effect of orthodontic treatment with fixed appliances. The purpose of this in-vitro study was to evaluate the efficacy of applying a light-cured filled sealant onto the buccal tooth surfaces to prevent demineralization.

METHODS

Fifty extracted human third molars were allocated to 1 of 5 groups: (1) enamel surface untreated (control); (2) surface etched; (3) fluoride varnish applied; (4) enamel etched and coated with a light-cured, unfilled sealant (control sealant); and (5) enamel etched and coated with a light-cured, filled sealant (Pro Seal, Reliance Orthodontic Products, Itasca, Ill). The enamel surface of each specimen was brushed for 15,000 strokes with nonfluoride toothpaste slurry with a piston-action brushing machine under a standardized load. All samples were then cycled for 14 days through a daily procedure of demineralization for 6 hours and remineralization for 17 hours. Then the teeth were sectioned and evaluated quantitatively by cross-sectional microhardness testing.

RESULTS

Demineralization in the Pro Seal group was significantly less (P < .05) than in the other groups. Teeth treated with fluoride varnish exhibited 30% less demineralization than the control teeth, the enamel-etched teeth, and the teeth treated with a light-cured, unfilled sealant (P < .05).

CONCLUSIONS

Pro Seal can be considered for use as a preventive method to reduce enamel demineralization adjacent to orthodontic attachments, particularly in patients who exhibit poor compliance with oral hygiene and home fluoride use.

The effects of argon laser irradiation on enamel decalcification: An in vivo study

Enamel decalcification is a significant problem in orthodontic patients. The argon laser has been shown to reduce decalcification during an acidic challenge in vitro. The purpose of this study was to investigate the in vivo effects of argon laser irradiation on enamel decalcification during orthodontic treatment. Nine volunteers whose treatment plans included 4 first premolar extractions were enrolled in the study. The 36 extracted premolars were assigned to 1 of the following 4 groups: group 1, control group with no treatment; group 2 (pumice-laser), teeth were pumiced for 3 seconds and treated with a 325 mW, 5-mm diameter laser beam for 60 seconds; group 3 (pumice-etch-laser), teeth were pumiced for 3 seconds, acid-etched with 30% phosphoric acid for 30 seconds, and treated for 60 seconds with laser; and group 4 (laser only), teeth were treated for 60 seconds with laser. A specially designed (oversized) orthodontic band was fitted on each of the premolars to create a pocket for decalcification. The bands were cemented in place for 5 weeks. After extraction, the teeth were sectioned and examined under polarized light microscopy. Images of lesions were digitally analyzed and measured. Average lesion depths were calculated from 3 depth measurements recorded 10 microm apart. Average lesion area was calculated with the aid of imaging analysis software. Data were analyzed with analysis of variance (P <.05) and Student t tests. Significant differences were found in lesion depth (P <.001) and lesion area (P <.01) among the 4 test groups. The average lesion depths were 15.93 +/- 9.31 microm (control), 6.45 +/- 8.70 microm (pumice-laser), 1.71 +/- 4.82 microm (pumice-etch-laser), and 1.34 +/- 3.80 microm (laser only). The average lesion areas were 1028.67 +/- 725.68 microm (2) (control), 555.49 +/- 948.20 microm (2) (pumice-laser), 79.91 +/- 226.03 microm (2) (pumice-etch-laser), and 55.71 +/- 157.59 microm (2) (laser only). The average lesion depth in the laser-only group was reduced by 94.1% and the average lesion area was reduced by 94.4% when compared with the control group. In the pumice-etch-laser group, the average lesion depth was reduced by 89.1% and the average lesion area was reduced by 92.2% when compared with the control group. There were no significant differences in lesion depth and lesion area between maxillary and mandibular teeth (P <.06 and P <.08, respectively) and between the teeth on the right and left sides (P <.68 and P <.55, respectively). These results show that argon laser irradiation is effective in reducing enamel decalcification during orthodontic treatment. Pumicing and etching do not appear to reduce the effect of laser on enamel solubility.