Ex vivo evaluation of the antimicrobial properties, physical and mechanical characteristics, and cytotoxicity of orthodontic cement containing silibinin against Streptococcus mutans biofilm.

Aim To test the hypothesis that enamel surface deproteinisation with different concentrations of bromelain in association with 10% papain increases the shear bond strength (SBS) of brackets bonded with orthodontic composite and resin modified glass ionomer cement (RMGIC). Materials and methods Orthodontic brackets were attached according to the following protocols to 195 bovine incisors, which were acquired and divided into 13 groups: 1) Transbond XT (TXT) according to the manufacturer’s recommendations; 2) Deproteinisation with 3% bromelain (BD) plus 10% papain and TXT; 3) 6% BD plus 10% Papain and TXT; 4) RMGIC, without enamel deproteinisation and without acid etching; 5) RMGIC, with 3% BD plus 10% papain and without acid etching; 6) RMGIC, with 6% BD plus 10% papain and without acid etching; 7) attachment using RMGIC following etching with polyacrylic acid; 8) 3% BD plus 10% papain, attachment using RMGIC and etching with polyacrylic acid; 9) 6% BD plus 10% papain, and attachment using RMGIC following etching with polyacrylic acid; 10) etching with 37% phosphoric acid and attachment using RMGIC; 11) 3% BD plus 10% papain, etching with 37% phosphoric acid and attachment using RMGIC; 12) 6% BD plus 10% papain, etching with 37% phosphoric acid and attachment using RMGIC; 13) deproteinisation with 2.5% sodium hypochlorite (NaOCl), etching with polyacrylic acid and RMGIC. After bonding, the brackets were removed by a universal mechanical testing machine, which recorded shear bond strength at failure. The material remaining on the tooth was assessed using the adhesive remnant index (ARI). Results Deproteinisation with 3% and 6% bromelain gel plus papain significantly increased the shear bond strength (p < 0.05), when acid etching was performed with phosphoric acid, followed by primer application and attachment using Transbond XT (Group 3) and when attached with RMGIC without etching. Deproteinisation with 6% bromelain gel plus papain significantly increased (p < 0.05) the ARI score only when attachment was performed using RMGIC, without etching (Group 6). Conclusions Deproteinisation with bromelain associated with papain in a gel increased the shear bond strength and is recommended before orthodontic bracket attachment.

Introduction: There is a high prevalence of enamel caries around brackets due to the young age of the majority of orthodontic patients, and to the difficulty of plaque removal in presence of orthodontic appliances. Recently, protective agents such as bioactive glasses (BGs) were introduced to enhance remineralization and prevent demineralization of tooth structures. This study aimed to assess the shear bond strength (SBS) of resin-modified glass ionomer cement (RMGIC) with addition of 45S5 BG to enhance its remineralizing potential using two conventional methods. Material and methods: This in-vitro experimental study evaluated three groups (n=20) of orthodontic brackets bonded to enamel using Transbond XT (group 1), light-cure RMGIC (group 2) and RMGIC with BG added (group 3). Samples underwent 7000 thermal cycles and their SBS was measured. The adhesive remnant index (ARI) score was also determined. Quantitative data were analyzed using one-way ANOVA while qualitative data were analyzed using a chi-square test. Discussion: The results showed no significant difference in SBS between study groups, however the ARI scores were significantly different among the groups. The RMGIC group showed the highest ARI while RMGIC doped with BG showed the lowest ARI score. Conclusion: Addition of 30% w/v 45S5 BG to RMGIC does not cause a significant change in SBS of orthodontic brackets bonded to enamel, while resulting in less amount of luting agent remnants on the enamel surface after debonding.

Introduction: Orthodontic adhesives should possess adequate bond strength and biocompatibility. Inadequate bond strength may lead to bond failures, and if the adhesive is not biocompatible, it may result in allergic reactions. Therefore, it is of prime importance to study the cytotoxicity and Shear Bond Strength (SBS) of commercially available orthodontic materials. Aim: This study aimed to comparatively evaluate in-vitro cytotoxicity, the Adhesive Remnant Index (ARI), and SBS of various orthodontic adhesives. Materials and Methods: This in-vitro study was conducted in an institutional setting as a collaborative effort between the Department of Orthodontics and White Lab-Blue Lab at Saveetha Dental College and Hospital, Chennai, India, from July 2023 to August 2023. Forty extracted human premolar teeth were bonded with four different ARI adhesives (U Bond, Enlight, Transbond XT, Aqualine LC) (n=10/group) and mounted on acrylic blocks. They were evaluated for SBS using a Universal Testing Machine (UTM), ARI using Scanning Electron Microscopy (SEM), and cytotoxicity using the MTT {3-(4, 5-dimethylthiazolyl2)-2, 5-diphenyltetrazolium bromide} assay on Human Gingival Fibroblast Cells (HGFC). Statistical analysis was performed using One-way ANOVA, with a post-hoc test for pairwise comparison to evaluate the SBS values, and the Kruskal-Wallis Test to analyse ARI inter group scores and cytotoxicity levels. Statistical Package for the Social Sciences (SPSS) software (Version 23.0) was used to conduct the statistical tests. Results: Significant differences in SBS values (p=<0.001) and ARI scores (p=<0.001) were noted between the different adhesives. No significant difference (p-value=0.534) in cytotoxicity was observed among all adhesives, with all exhibiting acceptable levels of biocompatibility. Conclusion: Primer-based adhesive (Transbond XT) demonstrated the highest SBS and ARI scores among the various orthodontic adhesives, with acceptable levels of biocompatibility. No significant difference was found between the conventional primer-based adhesive (Transbond XT) and the Single Component Adhesive (SCA) (Aqualine LC). Therefore, this study advocates for the use of SCA in routine clinical practice.

Antibacterial orthodontic cement to combat biofilm and white spot lesions.

Residents' journal review

This study aimed to analyze the shear bond strength (SBS) of ceramic orthodontic brackets bonded with two different adhesive systems to intact and eroded teeth. Ceramic brackets were bonded to 72 bovine central incisors divided into four groups, defined by two study factors: enamel condition (control group, kept in artificial saliva; and experimental group, eroded by using immersion cycles in Coke™ for 90 seconds, every six hours for five days), and adhesive system type (Transbond™ XT or Transbond™ Plus Color Change). Polycrystalline ceramic brackets were adhesively fixed on all specimens using the same light curing protocol. SBS was tested using 0.5 mm/min and the failure mode was classified. SBS data was analyzed using two-way ANOVA followed by Tukey test. The adhesive remnant index (ARI) scores were analyzed using Kruskal-Wallis test with Dunn's post-hoc pairwise comparison (α=0.05). Percentages of ARI scores between the groups were compared by Fisher’s exact test. Spearman's correlation coefficient was applied to investigate the correlation between ARI scores and SBS values. Only the adhesive system factor had significant effect on SBS (p=0.014), Transbond™ Plus Color Change showing higher values. No significance was found for enamel condition (p=0.665) or the interaction between adhesive system and enamel condition (p=0.055). ARI scores frequencies differed between groups (p<0.001). The median ARI scores were statistically different for most comparisons among the groups. However, no significant correlation was found between ARI scores and SBS. In conclusion, the type of adhesive system affected the SBS of ceramic brackets to dental enamel, but the enamel condition, intact or eroded, had no significant effect. There was no correlation between ARI scores and SBS values, although eroded enamel tended to retain more adhesive after bracket removal.

Aims:A new Resin Modified Glass Ionomer Cement known as nanoionomer containing nanofillers of fluoroaluminosilicate glass and nanofiller 'clusters' has been introduced. An in-vitro study aimed at evaluating shear bond strength (SBS) and adhesive remnant index (ARI) of nanoionomer under etching/unetched condition for use as an orthodontic bonding agent.Material and Methods:A total of 75 extracted premolars were used, which were divided into three equal groups of 25 each: 1-Conventional adhesive (Enlight Light Cure, SDS, Ormco, CA, USA) was used after and etching with 37% phosphoric acid for 30 s, followed by Ortho Solo application 2-nanoionomer (Ketac™ N100, 3M, ESPE, St. Paul, MN, USA) was used after etching with 37% phosphoric acid for 30 s 3-nanoionomer was used without etching. The SBS testing was performed using a digital universal testing machine (UTM-G-410B, Shanta Engineering). Evaluation of ARI was done using scanning electron microscopy. The SBS were compared using ANOVA with post-hoc Tukey test for intergroup comparisons and ARI scores were compared with Chi-square test.Results:ANOVA (SBS, F = 104.75) and Chi-square (ARI, Chi-square = 30.71) tests revealed significant differences between groups (P < 0.01). The mean (SD) SBS achieved with conventional light cure adhesive was significantly higher (P < 0.05) (10.59 ± 2.03 Mpa, 95% CI, 9.74-11.41) than the nanoionomer groups (unetched 4.13 ± 0.88 Mpa, 95% CI, 3.79-4.47 and etched 9.32 ± 1.87 Mpa, 95% CI, 8.58-10.06). However, nanoionomer with etching, registered SBS in the clinically acceptable range of 5.9–7.8 MPa, as suggested by Reynolds (1975). The nanoionomer groups gave significantly lower ARI values than the conventional adhesive group.Conclusion:Based on this in-vitro study, nanoionomer with etching can be successfully used as an orthodontic bonding agent leaving less adhesive remnant on enamel surface, making cleaning easier. However, in-vivo studies are needed to confirm the validity of present findings.

BACKGROUND:An ideal orthodontic adhesive should provide a bond strong enough to withstand the forces of orthodontic treatment and mastication without dislodging, while also being safe enough to prevent surface damage debonding. Shear bond strength (SBS) is a critical factor that determines the quality of bonding in orthodontics. Nanoparticle-enhanced adhesives have been reported to offer additional benefits such as antimicrobial properties and remineralization effects, making them worth investigating for their shear bond characteristics. Aim: This in vitro study aimed to evaluate and compare the SBS and Adhesive Remnant Index (ARI) scores of orthodontic adhesives containing copper-substituted hydroxyapatite (Cu-HA) nanoparticles with a conventional orthodontic adhesive.MATERIALS AND METHODS:Twenty-eight extracted human premolar teeth were randomly divided into two groups of 14. In Group 1, orthodontic brackets were bonded using Enlight adhesive mixed with Cu-HA nanoparticles, while Group 2 used conventional Enlight adhesive. SBS was measured using a Universal Testing Machine, and the debonded samples were evaluated for ARI scores under scanning electron microscopy (SEM). Statistical analyses were performed using independent t-tests for SBS comparison and Mann-Whitney U tests for ARI score differences. A P value < 0.05 was considered statistically significant.RESULTS:The group using Enlight adhesive with Cu nanoparticles exhibited a significantly higher mean SBS (9.03 ± 6.17 MPa) compared to the conventional adhesive group (5.51 ± 2.099 MPa, P = 0.003). The median ARI score for the Cu-HA nanoparticle group was 3, while the conventional group had a median ARI score of 2 (P = 0.022). Both SBS and ARI scores were significantly higher in the Cu-HA nanoparticle group.CONCLUSION:Copper-substituted hydroxyapatite nanoparticles enhance bond strength and adhesive retention, making them a promising alternative to conventional adhesives in orthodontics.CLINICAL RELEVANCE:The findings indicate that adhesives containing Cu-HA nanoparticles, especially when combined with the Enlight adhesive, offer superior bond strength and adhesive retention compared to conventional adhesives. This could lead to improved clinical outcomes in orthodontic bonding, potentially reducing bracket failure rates and enhancing treatment efficiency.

Influence of bioactive varnish on the shear bond strength of orthodontic brackets

To evaluate the shear bond strength(SBS) and bond failure interface after the debonding of orthodontic brackets with a resin-modified glass ionomer cement(RMGIC) under six bonding conditions, 140 premolar teeth were randomly divided into seven groups. The brackets of all groups, except for control group, were bonded using a RMGIC. The teeth were debonded using a universal testing machine. The shear bond strength, adhesive remnant index (ARI) and enamel fracture were examined for each debonding. A significant difference existed in SBS under wet and dry conditions in two groups of Fuji Ortho LC. Different degree of enamel fracture was seen in groups of Fuji Ortho LC(dry/37% phosphoric acid treated) after debonding. Bond failed predominantly at the enamel-adhesive interface, except for phosphoric acid treated groups. The RMGIC achieve a clinically effective adhesion in orthodontics under different bonding conditions.

Effect of incorporating silica-hydroxyapatite-silver hybrid nanoparticles into the resin-modified glass ionomer on the adhesive remnant index score and shear bond strength of orthodontic metal brackets: An in vitro study

IntroductionDevelopment of white spot lesions (WSLs) during orthodontic treatment is a common risk factor. Fixation of the orthodontic appliances with glass ionomer cements could reduce the prevalence of WSL’s due to their fluoride release capacities. The purpose of this study was to evaluate differences of fluoride release properties from resin-modified and conventional glass ionomer cements (GICs).MethodsThe resin-modified GICs Fuji ORTHO LC (GC Orthodontics), Meron Plus QM (VOCO), as well as the conventional GICs Fuji ORTHO (GC Orthodontics), Meron (VOCO) and Ketac Cem Easymix (3M ESPE) were tested in this study. The different types of GICs were applied to hydroxyapatite discs according to the manufacturer’s instructions and stored in a solution of TISAB III (Total Ionic Strength Adjustment Buffer III) and fluoride-free water at 37°C. Fluoride measurements were made after 5 minutes, 2 hours, 24 hours, 14 days, 28 days, 2 months, 3 months and 6 months. One factor analysis of variance (ANOVA) was used for the overall comparison of the cumulative fluoride release (from measurement times of 5 minutes to 6 months) between the different materials with the overall level of significance set to 0.05. Tukey’s post hoc test was used for post hoc pairwise comparisons in the cumulative fluoride release between the different materials.ResultsThe cumulative fluoride release (mean ± sd) in descending order was: Fuji ORTHO LC (221.7 ± 10.29 ppm), Fuji ORTHO (191.5 ± 15.03 ppm), Meron Plus QM (173.0 ± 5.89 ppm), Meron (161.3 ± 7.84 ppm) and Ketac Cem Easymix (154.6 ± 6.09 ppm) within 6 months. Analysis of variance detected a significant difference in the cumulative fluoride release between at least two of the materials (rounded p-value < 0.001). Pairwise analysis with Tukey’s post hoc test showed a significant difference in the cumulative fluoride release for all the comparisons except M and MPQM (p = 0.061) and KCE and M (p = 0.517).ConclusionFluoride ions were released cumulatively over the entire test period for all products. When comparing the two products from the same company (Fuji ORTHO LC vs. Fuji ORTHO from GC Orthodontics Europe GmbH and Meron Plus QM vs. Meron from VOCO GmbH, Mannheim, Germany), it can be said that the resin-modified GICs have a higher release than conventional GICs. The highest individual fluoride release of all GICs was at 24 hours. A general statement, whether resin-modified or conventional GICs have a higher release of fluoride cannot be made.

22 specimens prepared with Cention and RMGIC were embedded in primary teeth mounted in acrylic for analysing shear bond strength. Shear bond strength was analysed using a universal testing machine. The modes of failure in samples were observed under a stereomicroscope and scanning electron microscope. 22 customised samples of Cention N and RMGIC were prepared and categorised as group A and group B, respectively. The flexural and compressive strengths of these samples were evaluated using a universal testing machine. The shear bond strength of RMGIC was higher than that of Cention N, whereas the compressive and flexural strengths of Cention N were significantly higher than those of RMGIC. The modes of failure were predominantly adhesive followed by mixed failures. The results of this study suggest that Cention N demonstrated superior mechanical properties compared with RMGIC and can therefore be recommended for restorations in primary posterior teeth. Cention N being a smart, esthetic, self-cured, or dual-cured material with better mechanical properties offers a wide range of applicability in primary teeth.

The purpose of this study was to compare shear bond strength and to evaluate Adhesive Remnant Index (ARI) score among three chemically cured orthodontic adhesive resins, namely Unite (3M Unitek, USA), Rely-a-Bond (Reliance, USA) and Ortho-Force (China). Materials and methods: Ninety extracted human maxillary premolars were randomly divided into 3 groups (30 teeth/group). Upper premolar metal brackets (Ormco, USA) were boned by using the following adhesive systems: Unite, Rely-a-Bond and Ortho-Force. After 24 hours, shear bond strength was tested by using a Universal Testing Machine with a crosshead speed of 0.5 mm/min. After debonding, all teeth and brackets were examined under 10-times magnification and scored by using Image-Pro Plus 7.0 software program. Results: One-way ANOVA followed by post-hoc Tukey HSD multiple comparison test showed a statistically significant (P&lt;0.05) difference among groups. Ortho-Force had the lowest shear bond strength (17.53±3.60 MPa) and demonstrated statistically significant difference (P&lt;0.05) from the other groups. The difference between Unite (22.40±3.11 MPa) and Rely-a-Bond (20.67±2.70 MPa) was not statistically significant. The bond failure sites were categorized according to the ARI, and the Chi-square test showed significant differences in the ARI scores (P&lt;0.05) among all sample groups. The ARI score of 3 was found to be the most prevalent in Ortho-force (73.33%), followed by Unite (66.67%), and Rely-a-Bond (0%). In Rely-a-Bond group, ARI score of 1 was the most prevalent (66.67%). Only Unite had no residual adhesive left on tooth surface after debonding (6.67%). Conclusions: Unite and Rely-a-Bond produced greater shear bond strength than Ortho-Force. According to ARI score, Unite and Ortho-Force had a high frequency of all the adhesive remained on the tooth surface but Rely-a-Bond had high frequency of less than half the adhesive remained on the tooth surface.

Introduction Incorporation of remineralizing agents with fluoride-releasing bracket adhesives may prevent the development of white spot lesions (WSL) or reverse the established WSL in patients undergoing fixed orthodontic treatment. We aimed to find out how effectively casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and fluoride varnish (FV) can remineralize teeth when mixed with fluoride-releasing orthodontic adhesive. Materials and methods We randomly assigned a total of 60 premolar teeth, therapeutically extracted for orthodontic purposes, into two equal groups. Group I (n = 30) utilized fluoride-releasing adhesive (FR), and Group II (n = 30) bonded with non-fluoride adhesive (NFR). Based on the applied remineralizing agent, we further divided each of the two groups into three equal subgroups of 10: Group IA (FR+FV), Group IB (FR+CPP-ACP), Group IC (control-only FR), Group IIA (NFR+FV), Group IIB (NFR+CPP-ACP), and Group IIC (control-only NFR). Following bonding procedures, all the samples underwent pH cycling for 28 days, where the enamel samples were immersed in 20 ml of demineralizing solution for three hours, followed by immersion in 30 ml of remineralizing solution for 17 hours. The samples were analyzed for shear bond strength (SBS) on a universal testing machine and hardness values (HV) by the Vickers microhardness test (VMT) using the indentation method. We also evaluated the adhesive remnant index (ARI) scores to determine the site of bracket failure. Statistical analysis The shear bond strength (SBS) and hardness value (HV) were expressed as the mean, standard deviation (SD), and median for each subgroup. We used the non-parametric Kruskal-Wallis test to analyze the SBS and HV, followed by the Dunn-Bonferroni test for intra-pair differences. The ARI score was expressed as the frequency of the percentage distribution, and the difference in the distribution of ARI scores between the groups was assessed by the Cochran chi-square test. The probability (p) value equal to or less than 0.05 was considered statistically significant. Results The results show that Group IB, bonded with a fluoride-releasing adhesive and a CPP-ACP remineralizing agent surface treatment, has the highest HV of300.23 units. Group IIC (only NFR) has the lowest hardness of153.3 units, which is statistically significant (p < 0.001). However, the ARI scores are not statistically significant between the groups tested. Conclusion The bond strength of the adhesive and the surface hardness of the enamel increased with the addition of fluoride varnish and CPP-ACP to both the fluoride-releasing and non-fluoride-releasing adhesives.