Microleakage of orthodontic band cement at the cement-enamel and cement-band interfaces

Longevity of Aesthetic Fixed Space Maintainers in the Anterior Area of the Pediatric Dental Patient

Space maintenance for children at very early ages in primary molars or posterior sectors is widely used and the scientific evidence is clear as to its indications. In the anterior sectors there are doubts as to whether there is a loss of space and its use is usually accompanied by aesthetic, phonatory requirements or the completion of certain habits. In this type of aesthetic anterior maintainer, there are many medium and long-term complications that can occur.

PURPOSE

To evaluate the factors determining possible complications capable of reducing the longevity of aesthetic fixed space maintainers placed due to premature loss of temporary upper anterior teeth.

METHODS

Data were collected on 100 patients of 1-5 years of age requiring fixed space maintainer placement in the upper anterior area due to caries or traumatisms.

RESULTS

Complications were recorded in the form of resin tooth fracture (in 41% of the cases), welding fracture (16%), detachments (28%), gingivitis (26%) and root resorptions (8%). Space maintainer placement in younger children (12-24 months of age) was associated with a significantly greater incidence of root resorptions (p < 0.05).

CONCLUSIONS

Within the limits of the present study, it is concluded that fixed space maintainers would be a good treatment option in patients with prematurely missing anterior teeth, though the use of temporary first molars as abutments could imply a greater risk of failure, with a lesser incidence of root resorptions. Periodic checks and adequate measures of hygiene are essential.

Comparison between a glass ionomer cement and a compomer concerning bonded acrylic expander retention and white spot formation : A randomized clinical trial

BACKGROUND

The goal of the present study was to compare a compomer and a glass ionomer cement (GIC) used for full the cementation of acrylic splint-type maxillary expanders with respect to failure rate and white spot lesions (WSLs) in vivo.

METHODS

A total of 120 patients with posterior crossbite and transverse maxillary deficiency were included to the study. The patients were randomly allocated to two groups: GIC group (n = 60) and compomer group (n = 60). The hyrax screw in both groups was activated two times a day for the first week then once a day until the desired amount of expansion was achieved. The rapid maxillary expansion (RME) appliance was left in the mouth for an extra month after the active expansion phase as a retention appliance. Then cementation failures were recorded. In addition, the patients were evaluated for white spot lesions (WSLs) before cementation and after removal of the appliance.

RESULTS

A total of 12 (20%) and 2 (3.3%) RME devices failed in the GIC and the compomer group, respectively. This difference between groups was statistically significant (p = 0.044). There were also statistically significant differences between the GIC and compomer groups in terms of WSLs on the central (p = 0.06) and lateral (p = 0.011) incisors, and on the first molar (0.028). However, no differences were observed for the canines (p = 0.185), first (p = 0.457) and second premolars (p = 0.116). In total, there was a statistically significant difference between the GIC and compomer groups (p = 0.048), with more WSLs in the GIC group.

CONCLUSIONS

Among the products used in the study, the compomer should be preferred over the GIC for cementation of acrylic splint-type rapid maxillary expanders in terms of failure rate and WSLs.

Evaluation of Shear Peel Bond Strength of Different Adhesive Cements Used for Fixed Space Maintainer Cementation: An In Vitro Study

Aim and objective

This study aims to compare the retentive strength of different adhesive cements used for band cementation of fixed space maintainer by comparing the shear peel bond strength and mode of failure for each adhesive material using three different adhesive cements.

Materials and methods

Eighty intact extracted teeth were used to assess the shear peel bond strength. Preformed bands were adapted to each tooth. Three cements compared in this in vitro study are glass ionomer cement [Ketac Cem radiopaque (3M ESPE)], resin-modified glass ionomer cement [RelyX luting 2(3M ESPE)], and self-adhesive resin cement [RelyX U200 (3M ESPE)]. The teeth were randomly divided to four groups of 20 samples each. All samples were stored at 37°C for 24 hours before testing. All specimens were tested in a tensile mode using a universal testing machine to determine shear peel bond. After debonding procedure, each specimen was visually assessed at the site of cement.

Results

The results of our study showed that the greatest resistance to decementation was shown by self-adhesive resin cement (256.85 N) followed by resin-modified GIC (165.40 N) and GIC (127.40 N) (p < 0.001). Self-adhesive resin cement has the greatest shear peel bond strength (2.36 MPa) followed by resin-modified GIC (1.53 MPa), conventional GIC (1.22 MPa), and bands without cementation (0.29 MPa) (p < 0.001). In terms of adhesive remnant index (ARI) scores, it was seen that the decementation of bands of both conventional GIC and self-adhesive resin cements occurred at the band/enamel interface. However, resin-modified GIC showed varied results in the ARI scores.

Conclusion

The findings of our study suggest that self-adhesive resin cements can be used for cementation of bands of fixed space maintainers. However, further research with short-term and long-term data is required to evaluate the ability of these cements for its application in vivo.

How to cite this article

Kaur J, Singh A, Sadana G, et al. Evaluation of Shear Peel Bond Strength of Different Adhesive Cements Used for Fixed Space Maintainer Cementation: An In Vitro Study. Int J Clin Pediatr Dent 2021;14(2):175-179.

Evaluation of Microleakage of Orthodontic Bands Cemented With CPP-ACP-Modified Glass Ionomer Cement

Aims and Objectives:

In recent years, researchers have focused on finding methods of eliminating caries and white spot lesions under orthodontic bands without requiring patient cooperation. One of the effective and preventive strategies is the addition of antibacterial and remineralizing agents to the band cement. However, modifying the cement should not lead to microleakage and weakening of its mechanical properties. This in vitro study represents a continuation of our previous work of investigating the retentive strength of orthodontic bands cemented with casein phosphopeptide-amorphous calcium phosphate (CPP-ACP)-modified glass ionomer cement (GIC).

Material and Methods:

60 extracted human premolars were randomly divided into two groups (n = 30). In group 1, stainless steel bands were cemented with GIC. In group 2, a novel dental caries-preventive material, CPP-ACP, was incorporated into the GIC for cementing. The microleakage of each group was measured by the fluid filtration method.

Results:

Results showed no statistically significant difference in microleakage of either group (GIC and CPP-ACP-modified GIC).

Conclusion:

We concluded that 1.56% w/w CPP-ACP can be incorporated with GIC for cementing orthodontic bands without promoting microleakage.

Micro-CT evaluation of microleakage under orthodontic ceramic brackets bonded with different bonding techniques and adhesives

AIM

The aim of this study was to evaluate microleakage under orthodontic ceramic brackets bonded with direct and different indirect bonding techniques and adhesives using micro-computed tomography.

MATERIALS AND METHODS

A total of 30 human maxillary premolars were randomly separated into five groups with six teeth in each group. In group I, teeth were bonded directly with Transbond XT (3M Unitek). In group II, group III, group IV, and group V, teeth were bonded through an indirect technique with Custom I.Q. (Reliance Orthodontic Products), Sondhi Rapid-Set (3M Unitek), RMbond (RMO), and Transbond IDB (3M Unitek), respectively, following the manufacturer's instructions. Micro-CT system model 1172 of Skyscan (Kontich, Belgium) was used to scan all samples. NRecon (Skyscan) version 1.6, CT-Analyser V.1.11 (Skyscan), and TView (SkyScan, Bvba) software programs were used for microleakage evaluation. Microleakage values between the test groups were assessed using the Kruskal-Wallis test, while the Wilcoxon signed rank test was used for within-group comparisons. The level of significance was set at P < 0.05.

RESULTS

According to the Kruskal-Wallis analysis of variance test, there were no significant differences among the tested groups, with regard to volume and percentage (microleakage/region of interest × 100) of microleakage values (P < 0.05). The Wilcoxon signed rank test showed that coronal microleakage volume and percentage values significantly differed for RMbond and Transbond IDB groups.

LIMITATIONS

In the study, only ceramic brackets were used and microleakage into mini gaps did not show up on the micro-CT image because 50% silver nitrate solution could not penetrate into mini gaps which are smaller than silver nitrate particles.

CONCLUSION

Use of direct and indirect bonding techniques with different adhesives did not significantly affect the amount of microleakage.

Microleakage under orthodontic brackets bonded with different adhesive systems

OBJECTIVE

This in vitro study aimed to compare the microleakage of orthodontic brackets between enamel-adhesive and adhesive-bracket interfaces at the occlusal and gingival margins bonded with different adhesive systems.

MATERIALS AND METHODS

A total of 144 human maxillary premolar teeth extracted for orthodontic reasons was randomly divided into four groups. Each group was then further divided into three sub-groups. Three total-etching bonding systems (Transbond XT, Greengloo and Kurasper F), three one-step self-etching bonding systems (Transbond Plus SEP, Bond Force and Clearfil S3), three two-step self-etching bonding systems (Clearfil SE Bond, Clearfil Protectbond and Clearfil Liner Bond), and three self-adhesive resin cements (Maxcem Elite, Relyx U 100 and Clearfil SA Cement) were used to bond the brackets to the teeth. After bonding, all teeth were sealed with nail varnish and stained with 0.5% basic fuchsine for 24 h. All samples were sectioned and examined under a stereomicroscope to score for microleakage at the adhesive-enamel and adhesive-bracket interfaces from both occlusal and gingival margins.

STATISTICAL ANALYSIS USED

Statistical analyses were performed with Kruskal-Wallis and Wilcoxon signed-rank tests.

RESULTS

The results indicate no statistically significant differences between the microleakage scores of the adhesives; microleakage was detected in all groups. Comparison of the average values of the microleakage scores in the enamel-adhesive and adhesive-bracket interfaces indicated statistically significant differences (P < 0.05). The amount of the microleakage was higher at the enamel-adhesive interface than at the bracket-adhesive interface.

CONCLUSIONS

All of the brackets exhibited some amount of microleakage. This result means that microleakage does not depend on the type of adhesive used.

Effects of plasma-emulating light emitting diode (LED) versus conventional LED on cytotoxic effects of orthodontic cements as a function of polymerization capacity

Objectives:

The study was aimed at evaluating, in vitro, cytotoxicity of four resin-based orthodontic cements (RBOC) as a function of degree of conversion (DC) and the light curing unit (LCU) employed on mouse fibroblast (L929).

Materials and Methods:

Nine samples were manufactured for each group of cements using plasma-emulating light-emitting diode (LED) and conventional LED. Toxicity was assessed by immersing four specimens to culture medium (24 h/37°C) for extracting residual monomer or cytotoxic substance. Cell mitochondrial activity of L929 cell was evaluated using methyl tetrazolium (MTT) test. DC was evaluated by Fourier transform infrared spectroscopy for five samples.

Results:

Cements, LCUs, and interaction between cements and LCUs were found to play a statistically significant role in cytotoxicity ( p < 0.0001). Opal band cement (OPAL) plasma LED was found noncytotoxic (90–100% cell viability). The other RBOC–LCU combinations were slightly cytotoxic (60–90% cell viability). Cements ( p < 0.01) and LCUs ( p < 0.05) had a statistically significant effect on DC. Conversely, interaction between cement and LCU had no statistically significant role on DC ( p > 0.05). OPAL plasma LED displayed the highest levels of DC. The correlations between cell viability and DC were positive for three RBOCs.

Conclusion:

Therefore, high-intensity LCUs can be said to efficiently affect polymerization, so higher DC rates may achieve higher cell viability rates.

Clinical Relevance:

Cements and LCUs must be matched to each another to result in higher DC and maximal biocompatibility. Dual cure systems presented relatively high cell survival and higher DC, thus expressing superior to single-cure systems with plasma LED.

Evaluation of the caries-preventive effect of three orthodontic band cements in terms of fluoride release, retentiveness, and microleakage

This in vitro study was undertaken to evaluate the caries-preventive effect of three orthodontic band cements (a dual-curing resinmodified glass ionomer cement [RMGIC] and two light-curing polyacid-modified composite resin [compomer] cements) in terms of fluoride release, retentiveness, and microleakage after thermocycling. The RMGIC (Ortholy Band Paste [GC Ortholy, Inc., Tokyo, Japan]) showed a significantly higher amount of cumulative fluoride release over 180 days (p<0.001) and significantly greater tensile bond strength (p<0.001) than the compomer cements (Transbond Plus [3M Unitek, Monrovia, CA, USA] and Ultra Band-Lok [Reliance Orthodontic Products, Inc., Itasca, IL, USA]). Its bond strength was unaffected by thermocycling (2,000 cycles), indicating good retentiveness, whereas that of the compomer cements significantly decreased after thermocycling. Moreover, it had lower dyepenetration scores, indicative of less microleakage. These findings suggest that the RMGIC may have a better caries-preventive effect than the compomer cements and is suitable for long-term orthodontic banding.

Comparison of the effect of three cements on prevention of enamel demineralization adjacent to orthodontic bands

Background and aims

This in vitro study was designed to compare enamel demineralization depths adjacent to bands cemented with zinc polycarboxylate, glass ionomer (GI) and resin-modified glass ionomer (RMGI), in order to achieve minimal enamel demineralization during orthodontic treatment.

Materials and methods

Sixty fully developed extracted third molars were randomly divided into three testgroups each containing 20 samples, used to cement orthodontic bands with zinc polycarboxylate, GI and RMGI. All samples were demineralized using White method using hydroxyapatite, latic acid and Carbapol for in vitro caries simulation, and then, immersed in 10% solution of methylene blue. The mean depth of dye penetration was assessed up to 0.1 millimeter, reflect-ing the depth of enamel demineralization. One way ANOVA and LSD statistical tests were employed to evaluate significant differences among groups.

Results

The highest dye penetration depth was seen in zinc polycarboxylate group, followed by GI, and RMGI groups, respectively, with significant differences among each two groups (P < 0.05).

Conclusion

The use of RMGI cement seems to present significantly better prevention of enamel demineralization adja-cent to orthodontics bands.

Microleakage between composite/wire and composite/enamel interfaces of flexible spiral wire retainers: direct versus indirect application methods

OBJECTIVE

The aim of this in vitro study was to compare the microleakage of flexible spiral wire retainers (FSWR) at composite/wire and composite/enamel interfaces produced by an indirect application method to that of a conventional direct application method.

MATERIALS AND METHODS

Forty freshly extracted human mandibular incisor teeth were randomly divided into two equal groups. Group 1 was bonded directly according to the manufacturer's recommendations. Group 2 consisted of 20 teeth bonded indirectly with Transbond LR as the adhesive and Sondhi Rapid Set A/B Primer (3M Unitek, Monrovia, CA, USA), a filled resin primer. After bonding, specimens were further sealed with nail varnish, stained with 0.5% basic fuchsine for 24 h, sectioned and examined under a stereomicroscope that measured microleakage at the composite/wire and composite/enamel interfaces from both mesial and distal margins. Statistical analyses were performed using Wilcoxon and Mann-Whitney U-tests with Bonferroni correction.

RESULTS

Statistical comparisons indicated that no statistically significant differences were observed between composite/wire and composite/enamel interfaces for direct vs. indirect application procedures (Direct method p = 0.630 and Indirect method p = 0.930). Comparisons of the microleakage scores between direct and indirect FSWR application groups at composite/wire and composite/enamel interfaces indicated no statistically significant microleakage differences at mesial or distal margins (Composite/enamel interface p = 0.361 and Composite/wire interface p = 0.270).

CONCLUSION

The type of FSWR application procedures (direct vs. indirect) did not significantly affect the amount of microleakage at the enamel/composite/wire complex.

Effects of high-intensity curing lights on microleakage under orthodontic bands

INTRODUCTION

Our objective was to compare the effects of 3 light-curing units (LCUs) (quartz-tungsten-halogen [QTH], light-emitting diode [LED], and plasma-arc curing [PAC]) on the microleakage patterns of a polyacid-modified composite (PAMC) for band cementation between the cement-enamel and the cement-band interfaces from the buccal, lingual, occlusal, and gingival margins.

METHODS

Sixty freshly extracted third molars were randomly divided into 3 groups of 20 teeth each. Microetched molar bands were cemented in all groups with the PAMC (Ultra Band-Lok, Reliance Orthodontic Products, Itasca, Ill) and cured for 30 seconds with the QTH (Hilux 350, Express Dental Products, Toronto, Ontario, Canada), for 20 seconds with the LED (Elipar Freelight 2, 3M Espe, Seefeld, Germany), or for 6 seconds with the PAC (Power-Pac, American Medical Technologies, Hannover, Germany). A dye penetration method was used for microleakage evaluation. Microleakage was determined with a stereomicroscope for the cement-band and cement-enamel interfaces from the buccal and lingual sides at the occlusal and gingival margins. Statistical analyses were performed with the Kruskal-Wallis and Mann-Whitney U tests. The level of significance was set at P <0.05.

RESULTS

The gingival sides in the LED and PAC groups had higher microleakage scores compared with those observed on the occlusal sides at both the cement-band and cement-enamel interfaces. The buccal sides had similar microleakage values compared with those on the lingual sides for the cement-enamel and cement-band interfaces in all LCU types. Statistical comparisons showed that there were statistically significant differences among the investigated LCUs at the cement-enamel interface (P <0.05). Post hoc comparisons showed statistically significant microleakage differences between the PAC (median, 0.950 mm), the QTH (median, 0.383 mm) (P <0.01), and the PAC and the LED (median, 0.558 mm) (P <0.05) LCUs at the cement-enamel interfaces.

CONCLUSIONS

The high-intensity curing device PAC is associated with more microleakage than the LED and QTH at the cement-enamel interface.