In Vitro Evaluation of 2% Chlorhexidine and Glutaraldehyde Application on the Microleakage of Composite Resin Restoration in Deciduous Teeth

   

Fatemeh Kargarian Marvasti¹, Koorosh Teymoornezhad² and Ghazaleh Daryakenari^3*

Citation: Marvasti K, Teymoornezhad K, Daryakenari G. In Vitro Evaluation of 2% Chlorhexidine and Glutaraldehyde Application on the Microleakage of Composite Resin Restoration in Deciduous Teeth.  J Oral Med and Dent Res. 6(3):1-10.

Received: September 01, 2025 | Published: September 14, 2025                                                 

Copyright ©️ 2025 Genesis Pub by Daryakenari G, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC BY 4.0). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author(s) and source are properly credited.

DOI: https://doi.org/10.52793/JOMDR.2025.6(3)-104

Abstract

Background: Various materials are suggested for dentine rewetting, disinfection, and desensitization of a restoration cavity. Glutaraldehyde and Chlorhexidine are among the most common agents used frequently for their proven beneficial effects, such as desensitization, antibacterial, and enhanced bond strength and longevity.

Aim: The aim of this study was to evaluate the effect of separate and simultaneous application of these two agents on the microleakage of resin composite restorations of deciduous teeth.

Design: Two cavities were prepared on 52 deciduous teeth (n = 13). The samples were then randomly divided into 4 study groups according to their pre-bonding treatment. (1) Control group; (2) Glutaraldehyde treatment; (3) 2% chlorhexidine treatment and (4) simultaneous use of both Glutaraldehyde and 2% Chlorhexidine solutions. Microleakage was measured under an optic microscope with 40x magnification and was graded from 0 to 4. Statistical analysis of the results was performed using one-way ANOVA and Kruskal-Wallis tests.

Results: The difference between microleakage of the study groups was not significant (p˃0.05).

Conclusion: Use of Glutaraldehyde and Chlorhexidine illustrates no negative effects on the microleakage of resin restorations; thus it can be presumed that using them is beneficial for desensitizing and antiseptic purposes.

Keywords

Microleakage; Glutaraldehyde; Chlorhexidine; Resin composite; Primary tooth; Deciduous tooth; In-vitro study.

Introduction

Today, dental caries is still the most common chronic childhood disease, despite all preventive efforts. Its prevalence has been reported even higher than asthma and hay fever. Caries In most cases (two-thirds) are present only at the occlusal surface of the tooth and the cumulative effects of caries with age have caused more than 95% of adults to experience caries [1].

Various treatments are performed to restore carries, including amalgam, composite, and indirect restorations. Nowadays, the use of composite restorations is more popular and has advantages such as more conservative preparation, more beauty, chemical bonding to the teeth, less heat transfer, repairability, no mercury in its composition, etc. [2]. The similarity of these restorations with the teeth is a significant point because this beauty has very good psychological effects on the patient.

In addition to the many benefits mentioned for composite restorations, these restorations also have disadvantages. Although isolation is important in all restorations, it is even more important in composite restorations, and as you know, proper isolation in children is a challenge due to the less cooperation of children. The prognosis, marginal leakage rate, and bond strength of composites have high technical sensitivity and depend on many details, including enamel and dentin etching time using light-curing time, the thickness of composite layers, etc. Composite restorations are also prone to wear, so should be limited in areas with high chewing forces [2].

One of the major disadvantages of composite restorations is microleakage after restoration. Microleakage means an undetectable clinical pathway for bacteria, fluids, chemicals, molecules and ions to pass through the surface between the restoration and the tooth [2,3]. This marginal leakage makes teeth with posterior composite resin more prone to recurrent decay than teeth with amalgam restorations [1].

Today, various methods are used to reduce the effect of microleakage. For example, the application of contemporary posterior composite resins (high volume of filler and reducing shrinkage of polymerization), and the use of enamel bevel can help. In addition, composites, bonding agents and acid etches under new developments are also useful [1]. Despite many improvements that have been made to composite systems, microleakage is still a problem.

Studies on antimicrobials such as 2% Chlorhexidine solution have been performed after acid etching (4). In many of these studies, in addition to the effect on microleakage, the bond strength has also been investigated, which usually had an inverse connection between the shear bond strength and microleakage, but this connection has not been confirmed [2,5].

In some studies, antimicrobials such as Chlorhexidine and Sodium Hypochlorite have been increased restoration microleakage [6]. Antimicrobials and disinfectants can reduce the number of bacteria in the cavity, so they are useful to prevent pulp inflammatory reactions; in the similar residual dentin thickness (RDT), the presence of bacteria in the cavity leads to more severe pulp inflammation [1]. But on the other hand, it should be noted that the use of antimicrobial solutions such as Chlorhexidine, may increase microleakage and thus increase the presence of bacteria after restoration.

In addition to the above, microleakage can cause post-restorative sensitivity [1,7]. some materials and methods have been used to reduce the sensitivity after restoration. Such as the application of Glutaraldehyde (Gluma Desensitizer®, Heraus Kulzer) [2]. Studies have also been conducted to investigate the effect of using this agent on microleakage [7]. It is important that the use of this substance, which is used to reduce one of the effects of microleakage, does not itself increase microleakage.

Silveira de Araújo et al. found dentin leakage was higher than enamel, which underscores the importance of quality adhesive systems on dentin [8]. On the other hand, thickness of deciduous teeth enamel is half thickness of permanent teeth enamel, so the importance will be higher in deciduous teeth [9].

Due to the importance of dental leakage, the controversy obtained from different researches and inadequate studies about deciduous teeth microleakage, this study evaluated the in vitro effect of Chlorhexidine and Glutaraldehyde (used separately and at the same time) on dental leakage of Composite Resin restorations.

Materials and Methods

Samples and setting

52 deciduous teeth were collected whose roots were physiologically adsorbed and exfoliated or extracted for orthodontic purposes and also had an intact crown without caries and visible cracks. After collection, the samples were washed and placed in 0.2% thymol solution (Merck, Germany) for 24 hours for disinfection, then kept in normal saline at room temperature until the study [10]. The tooth surface was cleaned with a scaling brush (additional stress such as heat from brushing on the tooth surface was avoided).

For evaluation of dentin microleakage on deciduous teeth, at first, with a diamond bur, the enamel of the tooth surface was removed on one side of the tooth, and then two class V boxes (3×1×1 mm dimensions) were prepared on the buccal and lingual surfaces of the crown of each deciduous tooth. No marginal bevel was created for the holes [11]. (Figure 1).

The cavity was prepared with 330 diamond bur with high speed handpiece and water spray [1] and each bur was used to cut only 6 teeth [10].

The samples were randomly divided into 4 equal groups (n = 13). All cavities were etched (phosphoric acid 35%, Ultradent, USA) for 15 to 20 seconds [2] and rinsed for 20 seconds and dried to create an frosty look [10].

Four different protocols were used before filling boxes as followed:

1. Control group no need for extra preparation.
2. Treatment of the box with Glutaraldehyde (Gluma Desensitizer, Kulzer,   Germany) for 45 seconds, then the cavity surface is dried, washed and re-dried [12].
3. Treatment of the box with 2% Chlorhexidine (Ultradent, USA) for 20 seconds and then drying it for 15 seconds [13].
4. First glutaraldehyde and then 2% Chlorhexidine were used, as mentioned earlier.

The restoration process continued for all groups. First, the fifth generation OptiBond bonding (Kerr, Switzerland) was placed on the cavity and dried with gentle air pressure for 5 seconds [2]. It was cured for 10 seconds with a light cure device (Woodpecker model LED_D, China) with at least 600mW / cm2 light intensity and 8mm probe diameter [10]. The Palfique Asteria composite (Tokuyama, Japan) was used in the cavity and polymerized for 20 seconds.

Outcomes Measures

Samples were thermocycled (Vafaei industrial, Iran) for 1500 cycles between 5 ° C and 55 ° C baths, with 30 seconds duration for each bath and 10 seconds interval for each movement between the baths. Then, the tooth surface was covered with two layers of nail polish up to 0.5 mm left to the margin of the cavity, and the apical entrance of the pulp was sealed with bee's wax [10]. The samples were kept in 0.5% fuchsin solution (Ziehl, Iran) at 37 ° C for 24 hours [14]. The specimens were cut in half occluso-gingivaly and the dye penetration was recorded using a Loop microscope (Nikon C-PS, Japan) with 40x magnification [10] (Table 1 and Figures 1 and 2).

Figure 1: The boxes on enamel and dentin. Microleakage scores.

 

Figure 2: Microleakage scores. A: score 0. B: score 1. C: score 2. D: score 3. E: score 4.

 

score	Dye penetration
0	None
1	Up to one-third of the cavity depth
2	One-third to two-third of the cavity depth
3	Complete dye penetration, but not the axial wall
4	Into the axial wall