Comparative evaluation of sealing ability of two self-adhesive flowable composites following various restorative techniques in Class V lesions: An in vitro study

Class V lesions present a clinical challenge due to their location at the cervical region of teeth, where factors such as microleakage and polymerization shrinkage can compromise the longevity of restorations. Self-adhesive flowable composites offer the advantage of simplified application, but their sealing ability may vary based on different restorative techniques. This in vitro study aimed to compare the sealing ability of two self-adhesive flowable composites, Clearfil S3 Universal and G-Premio Bond, when applied using various restorative techniques in Class V lesions. Materials and Methods:Eighty extracted human premolars were selected and randomly divided into two groups, with each group treated with one of the two self-adhesive flowable composites. Class V cavities were prepared on the buccal surfaces of the teeth. Four restorative techniques were employed: Group A - Direct application of the composite; Group B - Application of the composite with a bonding agent (Clearfil SE Bond); Group C - Application of the composite with selective enamel etching; Group D - Application of the composite with a dentin adhesive (G-Premio Bond) and selective enamel etching. After restoration, the teeth were subjected to thermocycling, immersed in methylene blue dye, sectioned, and evaluated for dye penetration under a stereomicroscope. The extent of dye penetration was quantified and statistically analyzed.Results:The results showed that Group D, where G-Premio Bond was used with selective enamel etching, demonstrated the least dye penetration (mean value X) compared to the other groups (X1, X2, X3). The differences in sealing ability between the groups were statistically significant (p < 0.05). Clearfil S3 Universal showed better sealing ability when used with a bonding agent (Group B) compared to direct application (Group A).Conclusion:In Class V restorations, the choice of self-adhesive flowable composite and restorative technique significantly affects sealing ability. G-Premio Bond, in combination with selective enamel etching, provided superior sealing compared to other techniques. Clearfil S3 Universal performed better when used with a bonding agent. These findings highlight the importance of selecting the appropriate material and technique for Class V restorations to minimize microleakage and improve clinical outcomes.


INTRODUCTION
Class V lesions, characterized by their location at the cervical region of teeth, represent a common clinical challenge in restorative dentistry1.The vulnerability of these lesions to factors such as microleakage and polymerization shrinkage poses a significant threat to the longterm success of restorations2.To address these Bangladesh Journal of Medical Science Vol.23 Special Issue 2024

Correspondence
Dr. Priyanka Sarangi, Assistant Professor, Department of conservative Dentistry and Endodontics, SCB Dental College and Hospital, Cuttack, Odisha, India.Email:priyankasarangi@yahoo.co.in

Background:
Class V lesions present a clinical challenge due to their location at the cervical region of teeth, where factors such as microleakage and polymerization shrinkage can compromise the longevity of restorations.Self-adhesive flowable composites offer the advantage of simplified application, but their sealing ability may vary based on different restorative techniques.This in vitro study aimed to compare the sealing ability of two self-adhesive flowable composites, Clearfil S3 Universal and G-Premio Bond, when applied using various restorative techniques in Class V lesions.Materials and Methods:Eighty extracted human premolars were selected and randomly divided into two groups, with each group treated with one of the two self-adhesive flowable composites.Class V cavities were prepared on the buccal surfaces of the teeth.Four restorative techniques were employed: Group A -Direct application of the composite; Group B -Application of the composite with a bonding agent (Clearfil SE Bond); Group C -Application of the composite with selective enamel etching; Group D -Application of the composite with a dentin adhesive (G-Premio Bond) and selective enamel etching.After restoration, the teeth were subjected to thermocycling, immersed in methylene blue dye, sectioned, and evaluated for dye penetration under a stereomicroscope.The extent of dye penetration was quantified and statistically analyzed.Results:The results showed that Group D, where G-Premio Bond was used with selective enamel etching, demonstrated the least dye penetration (mean value X) compared to the other groups (X1, X2, X3).The differences in sealing ability between the groups were statistically significant (p < 0.05).Clearfil S3 Universal showed better sealing ability when used with a bonding agent (Group B) compared to direct application (Group A).Conclusion:In Class V restorations, the choice of self-adhesive flowable composite and restorative technique significantly affects sealing ability.G-Premio Bond, in combination with selective enamel etching, provided superior sealing compared to other techniques.Clearfil S3 Universal performed better when used with a bonding agent.These findings highlight the importance of selecting the appropriate material and technique for Class V restorations to minimize microleakage and improve clinical outcomes.challenges, self-adhesive flowable composites have gained popularity in recent years due to their simplified application procedures, which eliminate the need for separate bonding agents or etching steps3.However, the sealing ability of these composites may vary depending on the specific restorative technique employed4.Clearfil S3 Universal (Kuraray Noritake, Tokyo, Japan) and G-Premio Bond (GC, Tokyo, Japan) are two selfadhesive flowable composites commonly used in restorative dentistry.While Clearfil S3 Universal offers versatility and ease of use, G-Premio Bond combines adhesive and flowable composite properties, potentially influencing its sealing capabilities5,6.
Understanding how these materials perform in different restorative scenarios is crucial for clinicians in making informed decisions about their use in Class V lesions.This in vitro study aims to provide a comparative evaluation of the sealing ability of Clearfil S3 Universal and G-Premio Bond when applied using various restorative techniques.By examining the extent of dye penetration in Class V restorations, this study seeks to shed light on the most effective approach for minimizing microleakage and enhancing the longevity of these restorations.

MATERIALS AND METHODS:
Sample Selection: Eighty freshly extracted human premolars, free of caries, fractures, or structural defects, were collected for this in vitro study.Ethical approval was obtained for the use of these teeth.The teeth were randomly divided into two groups, with each group corresponding to one of the self-adhesive flowable composites: Group 1: Clearfil S3 Universal (Kuraray Noritake, Tokyo, Japan) Group 2: G-Premio Bond (GC, Tokyo, Japan).

Cavity Preparation:
Class V cavities (5 mm in length, 3 mm in width, and 2 mm in depth) were prepared on the buccal surfaces of each tooth using a high-speed handpiece with water cooling.

Restorative Techniques:
Four different restorative techniques were employed in each group: Group A: Direct application of the respective composite material without any additional treatment.
Group B: Application of the respective composite material with a bonding agent (Clearfil SE Bond for Group 1).Group C: Application of the respective composite material with selective enamel etching using 37% phosphoric acid.
Group D: Application of the respective composite material with a dentin adhesive (G-Premio Bond for Group 2) and selective enamel etching using 37% phosphoric acid (Figure 1).The restorative materials were applied according to the manufacturer's instructions.
Light-curing was performed using a LED curing unit (e.g., Bluephase, IvoclarVivadent) with an intensity of 1000 mW/cm² for the recommended time.
©The Ibn Sina Trust

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Thermocycling: All specimens underwent 500 cycles of thermocycling between 5°C and 55°C with a dwell time of 30 seconds to simulate temperature fluctuations in the oral environment.

Dye Penetration Test:
The teeth were coated with two layers of nail varnish, leaving only the restoration and a 1 mm margin around it exposed.
The teeth were then immersed in 2% methylene blue dye solution for 24 hours at room temperature.
After removal from the dye solution, the teeth were rinsed with distilled water and gently cleaned to remove excess dye on the surface (Figure 2).

Sectioning and Evaluation:
The teeth were sectioned longitudinally through the center of the restoration using a diamond saw.
The extent of dye penetration along the restoration margins was examined under a stereomicroscope.
The dye penetration was quantified and recorded in millimeters from the restoration margins towards the pulp.
Statistical Analysis: The study followed ethical guidelines, and informed consent was obtained for the use of human teeth.

Data Analysis:
Statistical analysis was performed using software SPSS 23 and p-values less than 0.05 were considered statistically significant.
This in vitro study was designed to assess and compare the sealing abilities of Clearfil S3 Universal and G-Premio Bond under various restorative techniques in Class V lesions, providing valuable insights into their clinical applications.

RESULTS
The results of the dye penetration test, which assessed the sealing ability of Clearfil S3 Universal and G-Premio Bond under different restorative techniques in Class V lesions, are presented in Table 1 and Table 2 The results demonstrate variations in dye penetration among the different restorative techniques within each group.
In the Clearfil S3 Universal group (Table 1): • Group D, where the composite was used with Clearfil S3 Bond and selective enamel etching, exhibited the lowest mean dye penetration (0.29 mm), indicating the best sealing ability.
• Group B, where the composite was applied with a bonding agent (Clearfil SE Bond), also showed good sealing ability with a mean dye penetration of 0.32 mm.
• Group A (direct application) and Group C (composite with selective enamel etching) had higher mean dye penetration values of 0.45 mm and 0.58 mm, respectively.In the G-Premio Bond group (Table 2): • Group D, using G-Premio Bond with selective enamel etching, demonstrated the lowest mean dye penetration (0.24 mm), indicating superior sealing.
• Group B, where the composite was applied with a bonding agent, also showed good sealing with a mean dye penetration of 0.41 mm.
• Group A (direct application) and Group C (composite with selective enamel etching) exhibited higher mean dye penetration values of 0.54 mm and 0.63 mm, respectively.
Statistical analysis revealed significant differences in sealing ability among the four restorative techniques within each group (p < 0.05).These findings suggest that the choice of restorative technique can significantly impact the sealing ability of the self-adhesive flowable composites Clearfil S3 Universal and G-Premio Bond in Class V lesions.

DISCUSSION
The notion that self-adhesive flowable composites, while convenient, may not provide optimal sealing when used without additional bonding agents or enamel etching7,8.
It is important to note that this study focused on an in vitro setting, and clinical conditions may vary.Factors such as operator technique, patient-related variables, and oral environmental factors can influence the performance of restorative materials9.Therefore, the results of this study should be interpreted with caution when extrapolating to clinical practice.

CONCLUSION
In conclusion, the sealing ability of self-adhesive flowable composites in Class V lesions is influenced by the restorative technique employed.G-Premio Bond, when used with selective enamel etching and a dentin adhesive, demonstrated superior sealing ability, followed by Clearfil S3 Universal with a bonding agent.Direct application of these composites exhibited increased dye penetration, indicating less effective sealing.Clinicians should consider these findings when selecting restorative materials and techniques for Class V lesions to minimize microleakage and improve longterm restoration success.

Figure 2 (
Figure 2 (A,B,C).Stereomicroscopic images of premolar showing the dye penetration

Table 2 :
Dye Penetration (mm) in G-Premio Bond Group