Impact of Silver Diamine Fluoride and Cocoa Bean Husk Remineralization on Orthodontic Brackets Shear Bond Strength: Early and Long-Term Effects

Abstract

Objectives

This study aimed to investigate the effects of silver diamine fluoride (SDF) and cocoa bean husk (CBH) remineralization agents for white spot lesions (WSLs) on shear bond strength (SBS) of metallic orthodontic brackets, both in the short and long term.

Materials and Methods

A total of 120 sound premolars were categorized into two main groups based on early and long-term effects (groups A and B, respectively). Each group was subdivided into four subgroups, corresponding to the two tested materials, along with two control groups (positive and negative). Prior to orthodontic bracket bonding, each tooth underwent demineralization followed by remineralization using the two tested materials. SBS was evaluated for groups A and B after 24 hours and 6 months of bonding, respectively, following incubation in an oral-like environment.

Results

CBH demonstrated the highest early SBS of 18.5408 (2.191) MPa, which was significantly different from all other groups (p = 0.00, analysis of variance). However, it decreased significantly to 9.070 (0.097) MPa after 6 months (p = 0.00, independent t-test). In contrast, SDF exhibited significantly lower SBS than CBH (Duncan multiple range test), with 8.5550 (0.059) MPa and 8.797 (0.295) MPa at early and after 6 months, respectively, with significant differences between the two tested intervals (p = 0.007, independent t-test). A p-value of ≥ 0.05 was considered nonsignificant.

Conclusion

CBH effectively maintained appropriate SBS in both the short-term and long-term by remineralizing WSL associated with orthodontic treatment, despite a slight decline over time. In contrast, SDF treatment resulted in a lower SBS but exhibited greater stability over a longer duration.

 

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Keywords

brackets - cocoa bean husk mouth wash - demineralized enamel - remineralized enamel - shear bond strength - silver diamine fluoride

Introduction

The teeth, considered as a high complex biological structure, consist of the outer hard mineralized tissue (enamel and dentine) that enclose the soft tissue (pulp).[1] [2] The significant properties of the enamel surface are inability to regenerate after damage, making it more affected by demineralization which can be accelerated by the accumulation of the plaque and acidic bacteria, which make the enamel loose its main minerals such as calcium and phosphate from its surface, weakening its structure and making it more susceptible to decay.[2] [3]

However, the damage caused by demineralization can be mitigated through the remineralization process, which offers promising pathway to restore enamel structure and strength.[1] [4] This process involves redisposition of the minerals into the enamel, effectively reversing the early stage of demineralization and preventing further deterioration.[2] [3] [5] Different remineralization agents have been developed and employed to counteract the enamel demineralization. Each agent incorporates distinct active ingredient designed to promote enamel repair and prevent additional damage. Some of the most widely studied and utilized remineralizing agents include fluoride, which represents a cornerstone in the prevention and treatment of dental caries; fluoride has long been recognized for its ability to enhance remineralization and inhibit demineralization by promoting the formation of fluorapatite, a more acid-resistant mineral phase.[2] [3] [6] [7] Nano-hydroxyapitite mimics the natural composition of the enamel. Nano-hydroxyapatite directly deposits minerals onto the enamel surface restoring its integrity and improving resistance to acid attacks.[8] Bioactive glass, which is known for its ability to release ions such as calcium and phosphate, facilitates remineralization while also neutralizing acids in the oral environment.[9] Casein phosphopeptide-amophous calcium phosphate, which represents the compound, stabilizes both calcium and phosphate ions in the saliva, enhancing their availability for enamel remineralization and reducing the risk of caries development.[8] [9] Theobromine, which represents a naturally occurring compound found in cocoa, has gained attention for its ability to promote the remineralization process by supporting the deposition of hydroxyl apatite crystals.[8] [9] Each of the above-mentioned agents targets early stage of enamel caries often presenting as white spot lesion (WSL), by facilitating the remineralization process and restoring the lost minerals and enhancing the structure integrity of the enamel surface; also, these agents play a role in preventing the progression of caries and preserving the dental health.[10] [11]

Silver diamine fluoride (SDF) among the various remineralizing agents stands out as a highly effective and widely studied option. SDF is a colorless alkaline solution that contains a high concentration of fluoride making it a potential tool for caries prevention and treatment since it is approved by the U.S. Food and Drug Administration in 2014. Since then it has gained recognition in the global dental markets for its ability to arrest caries and progression and promote remineralization.[2] [3] SDF has a dual action combining the antimicrobial properties of the saliva with the remineralizing effects of the fluoride making it practically effective in treating early stage of dental caries and preventing further demineralization. SDF has been used in Japan since the 1970s and its adoption in other regions has expanded due to its proven efficacy, ease of application, and cost effectiveness[11]; however, its limitation is tooth discoloration in the treated area.[3] [4] [7] The chemical composition of SDF [Ag(NH₃)₂F] includes 5% fluoride, 25% silver, 8% ammonia, and 62% water. Silver serves as an antimicrobial agent, while fluoride promotes remineralization of demineralized enamel.[8] [12] Investigation has shown that a 38% concentration of SDF is ideal for preventing and arresting caries, particularly in primary teeth, when compared with other concentrations.[13] However, plant-based extracts and powders, like those from Theobroma cacao (cocoa), offer a promising, safe, and affordable method for remineralizing teeth. Cocoa, especially its active compound theobromine 13,7-dimethylxanthine, has gained attention in dental care. Theobromine, a crystalling, water-soluble alkaloid found in cocoal tea and chocolate, is seen as a potential alternative to fluoride because of its similar benefits. Additionally, cocoa-based products are said to be more affordable than traditional fluoride treatments making them an appealing option for dental care.[12] [13]

The scenario of enamel demineralization is a common concern during fixed orthodontic treatment, particularly in areas surrounding brackets, tubes, and orthodontic rings.[13] This phenomenon is often attributed to the difficulties patients encounter in maintaining optimal oral hygiene during orthodontic treatment. The presence of the orthodontic appliance in the oral cavity represents an undercut and rough surface that could increase the accumulation process, and subsequently to acid production, which promotes the enamel demineralization.[14] However, it is also plausible that these lesions excited prior to the orthodontic intervention in a subclinical form, only becoming more apparent during treatment. In such cases, remineralization therapy may have to be employed before initiating the orthodontic treatment to restore enamel integrity and mitigate the risk for further complications.[14] [15] The process of demineralization can significantly impact the ability to achieve adequate bond strength when etching remineralized enamel surfaces with phosphoric acid before bonding the orthodontic brackets. This remineralized enamel surfaces often exhibited altered surface properties compared with untreated surfaces, potentially compromising the effectiveness of the acid etching process. This could result in weaker adhesive bonding and reduced long-term stability of the brackets posing challenges for successful orthodontic treatments.[15] [16]

While several agents have been proposed to manage WSL, limited data exist comparing the long-term effectiveness of natural agents like cocoa bean husk (CBH) against established materials like SDF, particularly in relation to bracket adhesion. Understanding their effects on shear bond strength (SBS) can inform clinical decisions and improve orthodontic outcomes.

This study tested the null hypothesis that there is no significant difference in SBS of metallic orthodontic brackets among premolars treated with CBH, SDF, and control groups at each time interval (24 hours and 6 months). Additionally, it was hypothesized that there is no significant difference in SBS within each treatment group (CBH and SDF), between the two time intervals.

The objective of this study was to evaluate the effectiveness of two distinct re-mineralization agents SBS and CBH mouth wash on the SBS of the orthodontic brackets. Precisely, the current study aimed to assess how these treatments influence both immediate and delayed SBS, providing valuable insight into their potential effect on the effectiveness and longevity of orthodontic bonding, by comparing the remineralization agents. The study sought to determined their suitability for use in clinical practice, particularly in managing the enamel demineralization and ensuring durable orthodontic brackets adhesion.

 

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Materials and Methods

The present study was conducted in vitro, after receiving an ethical approval from the Research Ethics Committee of the University of Mosul, Collage of Dentistry, Mosul, Iraq (UoM.Dent/23/5).

Sample Size Calculation

The sample size of this study was determined using G*Power software version 3.1. To guarantee sufficient statistical power for detecting the less significant difference between the groups,[17] the significant level (α) was set at 0.05 and the statistical power was determined to be 0.80. Also, the effect size was set as medium effect size of Cohen's d = 0.4.17. Based on the above criteria, it was determined a total of 120 premolars would be adequate to achieve forceful and statistically meaningful results. This approach ensured the reliability and validity of the research finding while maintaining the methodological rigor.

 

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Sample Distribution

For this controlled in vitro experimental study, a total of 120 extracted premolars were recruited in this study. The teeth were randomly divided into eight experimental groups to evaluate the effect of various tested remineralization treatment on the SBS under different durability conditions.

 

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Sample Selection and Preparation

The premolars were carefully examined before selection for this study based on the specific inclusion criteria to ensure consistency and reliability in the results. Only premolars that are free from any surface defects, erosion, and hypoplastic deformities were selected for the current study. Prior to the experimental procedure, each tooth underwent thorough cleaning using ultrasonic scalar to remove any attached periodontal ligaments and surrounding soft tissue, leaving only the enamel surface intact for bonding.

After the cleaning, the teeth were rinsed thoroughly with tap water, gently brushed to eliminate any remaining debris. To prevent dehydration and inhibit bacterial growth during the study period, the samples were stored in thymol solution (0.01). This preservation method ensured the structural integrity of the teeth throughout the experiment.[6]

 

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Study Grouping

The entire set of the tooth samples was randomly divided into two main groups:

• Group A: samples subjected to immediate SBS testing 24 hours after bonding.

• Group B: samples subjected to delayed SBS testing after 6 months.

Each of the above main groups was subdivide into four subgroups, with 15 teeth assigned to each group. The randomization ensured equal representation of each treatment condition across both immediate and delayed SBS testing intervals, enhancing the reliability and validity of this study.

 

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Subgroup Specifics

 

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Subgroup A1: Control Negative (Sound Teeth)

This subgroup consists of tooth samples that underwent no demineralization procedure, where the enamel surface remained in its original health, serving as a baseline for comparison with other experimental groups. These sound premolars provide reference points to evaluate the effective of demineralization and remineralization treatment on the SBS.

 

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Subgroup A2: Control Positive (Demineralized and no Remineralization)

In this subgroup, the enamel demineralization was intentionally induced using standardized protocol. However, no remineralization treatment was applied following the demineralization process. This group served as baseline comparison to assess the effects of demineralization alone on bond strength, offering insight into how untreated demineralized enamel influences the adhesive properties of orthodontic brackets.

 

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Subgroup A3 (Demineralization + Remineralization with Cocoa Bean Husk Solution)

For this group, enamel demineralization was first induced followed by a remineralization treatment using a solution derived from CBH extract. The preparation of the CBH solution was performed by liquefying the extract's final powder of CBH in distilled water to attain a 1-mg/mL concentration, according to the method that was previously described.[12]

The teeth samples were thoroughly washed with distilled water to remove any residual debris of demineralizing solution, The samples were then immersed in the CBH solution for a duration of 7 days, allowing the remineralization process to occur. This step constituted the remineralization treatment using the CBH solution and was conducted according to a previously established method.[12]

 

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Subgroup A4: Demineralization + Remineralization with SDF

In this group, the remineralization was performed using SDF succeeding the demineralization of the tooth samples. SDF, in its solution form, was applied directly to the demineralized enamel surface.

The application process involves carefully applying the SDF solution to the teeth according to established protocols,[11] ensuring uniform coverage. The solution interacts with the enamel, facilitating their remineralization process by promoting the deposition of minerals on the enamel surface over a specified period, as per standard treatment procedures.

For group B (subgroups B1, B2, B3, and B4), the same procedures as those followed for the corresponding group A subgroups were applied with one key difference, the storage period bonding and prior to SBS,[15] [16] measurement was intended to 6 months as opposed to the 24-hour period used in group A. The adjusted slowed for the evaluation of the long effects of the mineralization treatments on bond strength.

Except for subgroups A1 and B1, all specimens are immersed in a de mineralizing solution containing 2.2 mM CaCl₂, 2.2 mM NaH₂PO₄, and 0.05 M acetic acid, the pH of the solution adjusted to 4.5 using 1 M KOH. This demineralization protocol was sustained for 96 hours at 37°C, as delineated in previous studies.[7] [8] Subsequent to the demineralization period, the tooth samples were rinsed thoroughly with distilled water to ensure the removal of any residual demineralizing solution, dried carefully, and then held in polyvinyl chloride (PVC) rings with suitable dimensions. The tooth specimens were embedded in custom-designed rings to ensure stability and precise positioning during the study. These rings were partially filled with dental stone to provide initial stabilization of the specimens. Subsequently, the rings were completely filled with autopolymerizing cold-cure acrylic resin to offer additional support and facilitate the subsequent bonding procedures.

Throughout the samples embedding procedure, care was reserved to position the root of the tooth within the acrylic resin, so that it was close to the cement-enamel junction. This specified position was critical to guarantee standardization across all samples. Additionally, meticulous attention was given to maintaining the tooth in a parallel orientation within the ring setup before allowing the acrylic resin to fully polymerize. This precise alignment ensured consistent and stable positioning of the teeth, minimizing variability and providing a reliable foundation for the subsequent SBS testing and analysis.

The current study ensures that all the tested teeth were exposed to identical environments, snowballing both the reproducibility and accuracy of the outcomes. This methodological precision played a significant role in gaining reliable data regarding the effects of various treatments on SBS.[13]

 

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Bonding Procedure

Following the mounting process, each tooth sample was polished using fluoride-free pumice for approximately 10 seconds to remove any surface debris or contaminants. The samples were then rinsed with a water spray for another 10 seconds and dried using moisture-free compressed air to prepare the enamel surface for bracket bonding

The buccal surface of each tooth was etched with 37% phosphoric acid gel (3M Uniteki, Monrovia, California, United States) for 60 seconds. After etching, the teeth were carefully rinsed with water and dried until a chalky appearance appeared, which indicates a successful enamel etching. Then, a thin layer of Transbond XT primer (3M Unitek) was then applied to the etched surface and cured using an light-emitting diode (LED) light (Valo, Ultra-dent Inc., Utah, United States). Subsequently, a metallic orthodontic bracket (0.022-inch slot Roth metal brackets, Dentarum, Germany) was forced centrally on the clinical crown after loading a sufficient amount of Transbond XT adhesive (3M Unitek). To ensure equal pressure during the bonding process, a 200-g weight was positioned at the articulator arm in a direction perpendicular to the bracket slot.9 Standardization in this manner ensured equal bonding conditions for all specimens, and variation in experimental results was minimized. Excess adhesive was carefully removed using a dental explorer (Hu-Friedy, Chicago, Illinois, United States), and curing was initiated with an Valo Ultra-dent LED light with a wavelength of 420 to 480 nm and irradiation intensity of 1200 to 1500 mW/cm². A curing radiometer (Woodpacker, China) was used to monitor and maintain consistent light intensity throughout the process, with calibration performed after every set of five samples to ensure accuracy. The tip of the curing device was positioned 2 mm away from the mesial and distal margins of the bracket base, and curing was performed for 10 seconds on each side.[10] This meticulous procedure ensured uniform and reliable bonding of the brackets for subsequent SBS testing.

 

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Storage Conditions

After bracket bonding, the specimens in group A were placed in sealed containers filled with distilled water and stored in an incubator maintained at a temperature of 37°C. They remained under these conditions for 24 hours before undergoing SBS testing.

In contrast, the specimens in group B were subjected to the same initial conditions but were stored for a longer duration of 6 months in the aging medium before SBS testing. This extended storage period adhered to the protocol outlined in Oesterle and Shellhart.[11] By comparing the bond strength results of both groups, the study aimed to evaluate the effects of immediate versus long-term durability on orthodontic bonding performance.

 

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Shear Bond Strength Measurements

The SBS between the brackets and tooth surface was calibrated using a universal testing machine (Model Type 500, Lloyd Instruments Ltd., Fareham, Hampshire, United Kingdom), which switched on crosshead speed set to 0.5 mm/min. The machine applied a controlled force to determine the point at which debonding occurred or when bracket failure began. The final debonding force was measured in Newton (N).

To standardize and quantify the bond strength, the outcomes were converted into megapascals (MPa) using the following formula according to a previously published article[17]:

where SBS (MPa) = Surface Area of Bracket Base (mm²) divided by Force (N)……..[17]

This equation allowed for the calculation of bond strength per unit area, providing critical data for analysis and comparison across the different experimental groups. The results were used to draw conclusions regarding the efficacy of various remineralization treatments on the immediate and long-term SBS of orthodontic brackets.

 

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Statistical Analysis

The outcomes of this study were analyzed using SPSS software. Descriptive statistics were employed to calculate the mean, minimum, maximum, and standard deviation of the SBS for all tested groups at two time points.

For further analysis, analysis of variance (ANOVA) and Duncan multiple range tests were conducted to identify and localize the significant differences between the tested groups with regard to the materials used at each time point separately. Additionally, an independent t-test was performed to compare the results between the two tested periods of each tested materials. The significance level was set at p ≥ 0.05.

 

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Results

According to the ANOVA statistical test, a highly statistically significant difference was observed between the immediate and long-term SBS of orthodontic brackets across the study groups ([Tables 1] and [2]). [Table 1] presents descriptive statistics and Duncan's multiple range test results, comparing SBS among the groups. The CBH mouthwash group exhibited the highest SBS, followed by the control negative (sound teeth), SDF, and control positive groups. [Table 2] reports delayed SBS after 6 months, showing the CBH group maintaining the highest SBS, followed by the control negative, SDF, and the lowest SBS in the control positive group. [Table 3] highlights the difference in SBS between immediate and delayed measurements, revealing a decline in SBS across all groups, with a statistically significant difference in all except the control positive group, where no significant change was observed.

Table 1 Descriptive statistics, ANOVA, and Duncan's multiple range test comparing the early (immediate) shear bond strength (in MPa) after 24 hours

Group		Minimum	Maximum	Mean[e]	ANOVA significance
Control (+)	15	4.00	4.41	4.1996 (0.1004)d	0.000[f]
SDF	15	8.46	8.66	8.5550 (0.059)c
Control (–	15	9.21	15.17	11.6404 (1.428)b
Cocoa husk	15	14.00	22.72	18.5408 (2.191) a

Abbreviations: ANOVA, analysis of variance; SDF, silver diamine fluoride.

^e Groups with different letters are significantly different from each other at p ≥ 0.05.

^f ANOVA significant level p ≥ 0.05.

Table 2 Descriptive statistics, ANOVA, and Duncan's multiple range test displayed the long-term shear bond strength (in MPa) after 6 months of aging medium

Group	Number	Minimum	Maximum	Mean (SD)[e]	ANOVA significance
Control (+)	15	3.10	4.51	4.049 (0.307)d	0.000[ f ]
SDF	15	8.44	9.79	8.797 (0.295)b
Control (–)	15	7.70	8.64	7.884 (0.213)c
Cocoa husk	15	8.91	9.37	9.070 (0.097)a

Abbreviations: ANOVA, analysis of variance; SD, standard deviation; SDF, silver diamine fluoride.

^e Groups with different letters are significantly different from each other at p ≥ 0.05.

^f ANOVA significant level p ≥ 0.05.

Table 3 The mean shear bond strength value of all tested groups with the independent t-test value which represent the difference between early and long-term shear bond strength

Group	Tested period	Number of samples	Mean SBS (MPa)	t-Value	Significance[a]
Control (+)	24 h	15	4.1996	1.790	0.091
	6 mo	15	4.0499	1.790
SDF	24 h	15	8.5550	–3.120	0.007
	6 mo	15	8.7976	–3.120
Control (–)	24 h	15	11.6404	10.074	0.000
	6 mo	15	7.8842	10.074
Cocoa husk	24 h	15	18.5408	16.718	0.000
	6 mo	15	9.703	16.718

Abbreviations: SBS, shear bond strength; SDF, silver diamine fluoride.

^a Significant level p ≥ 0.05 of independent t-test.

 

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Discussion

One of the main challenges associated with fixed orthodontic treatment is the development of WSLs on the enamel surface.[13] These lesions represent an early and reversible stage of demineralization, which, if left untreated, can progress to more severe forms of dental caries.[14] WSLs are characterized by localized mineral loss in the enamel, often caused by prolonged exposure to acidic plague and poor oral hygiene during orthodontic treatment. If not property managed these can lead irreversible enamel damage, posing significant aesthetic and functional drawbacks.[16] [18]

The aim of this study was to evaluate the effects of two different remineralization agents on demineralized enamel surfaces: specifically focusing on their impact on the SBS of metallic orthodontic brackets. The assessment was conducted both immediately after application and over a longer period of 6 months. The two remineralization agents investigated were SDF and a natural mouthwash containing an alcoholic extract of cocoa powder, with theobromine as its active ingredient.[11] [12] The study sought to determine how these agents influence enamel remineralization and whether they affect the bond strength of orthodontic brackets.

Numerous studies have demonstrated the efficacy of both SDF and CBH mouthwash in promoting enamel remineralization; these materials are not only effective but also widely accessible and cost-efficient making them attractive options for clinical use.[1] [2] [4] [11] [12] In particular, plant-based extracts and powders derived from Theobroma cacao (cocoa) have gained attention as safe and affordable alternatives for dental care.[12] Cocoa encloses theobromine, which is a crystalline, water-soluble alkaloid that has a potential effect in remineralization process. Theobromine is chemically identified as 3, 2-dimethylxanthine, which originates naturally in cocoa, tea, and chocolate. Its talent to stimulate enamel remineralization has been linked to fluoride, with the advantage of being less toxic and more cost-effective than traditional fluoride-based agents.[11] [12] To assess the mechanical performance of the materials, a universal testing machine were used to apply shear stress to the specimens. This technique is commonly employed in in vitro studies to evaluate SBS of orthodontic brackets, via exposing the samples to specific measurements. This method offers insights into the adhesion performance of dental adhesive system, serving to determine their aptness for clinical requests.[18] Generally, this study highlights the credibility of natural and cost-effective remineralization agents such as cocoa-derived products, as practical substitutes to traditional treatments. Via specifying the limitations of the current study, these agents could dramatically improve oral health outcomes for orthodontic patients by minimizing the complications of WSL.

One of the primary limitations of orthodontic treatments is the development of WSL.[18] These lesions represent an early, reversible, stage of demineralization proceeding to more advanced dental caries.[14] WSLs are characterized by a localized loss of mineral content in the enamel, which can potentially lead to irreversible damage, if not properly managed during and after orthodontic treatment.[1] [3] [6] [13]

In dental material research, the imposition of control groups (positive and negative) is essential for a comprehensive evaluation of the tested materials. Where the positive control serves as a standard, ensuring the validity of experimental settings by comparing tested materials against recognized treatments. While the negative control offers a baseline signifying the system's behavior in the absence of treatment, serving to identify natural tendencies and potential confounding variables. Together, both groups confirm a rigorous and reliable assessment of the materials being studied.[18] [19] [20]

In this study, the positive control group exhibited the lowest SBS values compared with the other groups in both short-term and long-term assessments. This outcome can likely be attributed to the destructive effects of the demineralizing solution on the enamel surface. Despite this, the positive control group provided valuable insights into the efficacy of the demineralizing solution used in the study.[24] [25] [26]

The study evaluated two treatment modalities: CBH mouthwash and SDF. The mean SBS values for most samples treated with CBH, as well as the control group, exceeded the clinically acceptable range of 6 to 8 MPa, as suggested by Reynolds and von Fraunhofer.[21] However, this was not the case for the SDF group, where both immediate and long-term SBS values were significantly lower. This reduction in bond strength may be due to SDF's potential to occlude dentinal tubules, thereby interfering with acid etching process and weakening the bond between the enamel and metallic brackets. The CBH group (A1 subgroup) demonstrated significantly higher SBS values 24 hours after bracket bonding, with a mean SBS of 18.2576 MPa. These findings align with the study by Elmalawany,[22] which explored the effects of remineralizing agents on micro-tensile bond strength (µTBS). Elmalawany's research showed that the application of theobromine—whether for 5 minutes or 1 month—restored µTBS values to levels comparable to sound dentin, significantly surpassing those observed in demineralized dentin.[22] Similarly, in our study, the application times used for CBH appeared to restore bond strength to levels similar to those of sound enamel, indicating a significant remineralization effect.[23] [27] [28] [29] However, it is worth noting the scarcity of studies directly comparing SBS following enamel pretreatment prior to bracket bonding. This gap in the literature underscores the novelty of our approach in assessing the impact of remineralizing agents on the bonding performance of metallic brackets.

Interestingly, no significant differences were observed between the immediate and long-term SBS values when SDF was applied to previously demineralized enamel. This could be attributed to the mechanism of action of SDF compared with CBH, which includes formation of calcium fluoride (Caf) on the enamel surface.[30] [31] The fluoride ions enhance remineralization and protect against future demineralization by facilitating the deposition of hydroxyapatite, the primary mineral in enamel through the binding of calcium and phosphate ions.[21] [30] [31] [32] This process creates a protective layer that increases enamel hardness and resistance to caries attacks, in contrast, CBH contain polyphenols, flavonoids, and antioxidants, which support the natural mineralization process and aid enamel remineralization.[22] [32] These compounds bind with calcium and phosphate ions making them available to strengthen the tooth surface.[25] [29] However the remineralization effect of CBH is mild compared with SDF, where CBH can reinforce enamel and improve resistance to demineralization, its impact less pronounced than that of fluoride-based agents like SDF.[29] [32]

CBH is expected to internet with calcium and phosphate ions to enhance enamel strength, possibly by supporting the natural remineralization process. However, it may not have an ability to be long-lasting as a protective obstacle as fluoride-based agent, such as SDF, which is documented for their ability to resist acid attacks.[28] [29] [32] This difference in durability could impact its effectiveness in preventing demineralization and maintaining good bond strength in orthodontic applications.

Overall, the current research findings highlight both the mechanisms and effects of CBH and SDF on enamel remineralization and SBS. As both these agents display benefits, their clinical applications may be essential to tailor according to the precise clinical requirements and patient desires. Further researches are required to discover their long-term effectiveness in orthodontic dentistry.

 

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Limitation

This study has a few limitations that are worth noting. First, it was conducted in vitro, which cannot fully capture the complexity of the oral environment in real life conditions, factors like saliva flow, temperature changes, and chewing forces play a big role in how materials and treatments behave since these elements were not part of the experiment, they might have influenced the results. Another point is that while we looked at SBS right after 24 hours of bonding and again after 6 months, however, no assessment was performed over an even longer period. This raises questions about how durable and stable the remineralized enamel would be under everyday oral conditions, Future studies should explore this to give us a clearer picture of how these agents hold up over time.

Also, this study focused only on two specific remineralization agents, CBH and SDF. However, further investigation recruiting other remineralizing agents, as well as combinations of treatments protocols, that could potentially work better or complement these findings is required. Discovering those options might open up new opportunities for improving the remineralization and SBS.

In summary, although this study offers valuable insights, further investigations are required to fully understand how these treatment options perform in actual clinical settings and to sightsee options to enhance their effectiveness.

 

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Clinical Application

The results of this study indicate that CBH, which contains the active compound theobromine, could be a promising alternative to fluoride for enamel remineralization. It is particularly beneficial for patients who are sensitive to fluoride or those who prefer natural treatment options with its potential to protect enamel. CBH could be incorporated into clinical practices to help manage WSL that often occur during orthodontic treatment.

Moreover, CBH might also serve as a supportive treatment in orthodontics, it has the potential to maintain or even enhance SBS, while reducing the risk of cavities forming around brackets and other appliances. For patients who are more prone to enamel demineralization or who already have early enamel decays from orthodontic treatments, using CBH alongside other remineralizing agents, could be a valuable addition to personalized care plans. This approach not only addresses individual patient needs but also promotes better, overall oral health during and after orthodontic therapy. Future research should investigate the efficacy of combining CBH with other remineralization agents, such as nano-hydroxyapatite or bioactive glass to further enhance enamel recovery and optimize bonding strength. In vivo studies are needed to assess the effectiveness of these treatments in real-world clinical settings.

 

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Conclusion

CBH effectively maintained appropriate SBS in both the short-term and long-term by remineralizing WSLs associated with orthodontic treatment, with theobromine providing significant enamel protection, despite a decline over time. In contrast, SDF treatments resulted in a lower SBS but exhibited greater stability over a longer duration.

 

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Conflict of Interest

None declared.

Acknowledgments

The authors thank the University of Mosul for their support to conducting this research.

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Artikel online veröffentlicht:
01. September 2025