|Year : 2019 | Volume
| Issue : 1 | Page : 9-14
Effect of ozonated water on dentin bond strength
Attiguppe R Prabhakar1, Ravi S Kumar2, Divya Prahlad3
1 Department of Pedodontics and Preventive Dentistry, Bapuji Dental College and Hospital, Davangere, Karnataka, India
2 Department of Pedodontics and Preventive Dentistry, KLE Society's Institute of Dental Sciences, Bengaluru, Karnataka, India
3 Pediatric Dentist, Medical Affairs, Ministry of Interior, Doha, Qatar
|Date of Web Publication||17-May-2019|
Dr. Attiguppe R Prabhakar
Room No. 3, Department of Pedodontics and Preventive Dentistry, Bapuji Dental College and Hospital, Davangere, Karnataka
Source of Support: None, Conflict of Interest: None
Objective: Residual bacteria under restorations can survive and proliferate even in the presence of a good seal. This can be prevented using adjunctive treatment with antibacterial agents during dentin bonding. However, its use can interfere with the bonding process. The current research was designed to study the influence of pretreatment with 2% chlorhexidine (CHX) gluconate (Consepsis), and ozonated water on shear bond strength, and microleakage of resin-modified glass ionomer cement (RMGIC) to primary tooth dentin.
Materials and Methods: Thirty-six noncarious primary molars were selected, and the study was conducted in two parts as follows: evaluation of (1) Shear bond strength and (2) Microleakage. The teeth were randomly divided into three groups as follows: group I – Distilled water (control), Group II – 2% CHX gluconate, and Group III – ozonated water. The shear bond test was done using a Universal Testing Machine (Instron, USA). The results were analyzed using one-way ANOVA for multiple group comparisons and post hoc Tukey's for group-wise comparison. Microleakage was evaluated using stereo microscope. The results were statistically analyzed using the Chi-square test for group-wise comparison.
Results: Bond strength was comparable across the three groups with distilled water showing the highest bond strength values followed by ozone group and 2% CHX group. CHX group showed significantly greater microleakage when compared with that of the ozone group.
Interpretation and Conclusion: Ozonated water did not affect the shear bond strength or the sealing ability of RMGIC to primary tooth dentin, and hence is a viable option for cavity disinfection.
Keywords: 2% chlorhexidine, cavity disinfectant, microleakage, ozone, resin-modified glass-ionomer cement, shear bond strength
|How to cite this article:|
Prabhakar AR, Kumar RS, Prahlad D. Effect of ozonated water on dentin bond strength. Int J Oral Health Sci 2019;9:9-14
| Introduction|| |
Minimally invasive dentistry involves cavity preparation limited to the removal of carious dentin. This is, however, difficult to achieve in pediatric practice owing to the lack of a definite diagnostic tool to clinically define the caries-removal endpoint, difficult compliance from an uncooperative child, and lack of an ideal anticariogenic restorative material effective in controlling growth and the activity of residual microorganisms.
These problems can be overcome by either incorporating antibacterial agents into the restorative materials which may, however, decrease the physical properties of the restorative material to unacceptable levels or the other alternative of using cavity disinfectant solutions to reduce or eliminate the bacteria from cavity preparations.
Chlorhexidine (CHX) has been found to be the most potent antimicrobial agent in addition to having a potential to reduce the postoperative sensitivity. However, its use may interfere with adhesive procedures to dentin. Although many studies have described the influence of CHX on bond strength in the permanent teeth to be effective, its effect in primary dentition is still unclear.
Ozone, a triatomic molecule, consisting of three oxygen atoms is a powerful oxidizing agent has been introduced in the dental practice due to its antimicrobial potential against common oral pathogens. Clinical studies assessed the effect of ozone for the treatment of occlusal and root caries, and more recently, the application of ozone on dental hard tissues as a cavity disinfectant before adhesive restorations has been proposed. The effect of ozone on bond strength to primary tooth dentin and on the sealing ability of restorative materials is still unknown.
It is desirable to use a cavity disinfectant that does not alter the physical properties of restorative material. Hence, this study was intended to evaluate the effect of ozonated water as a cavity disinfectant on adhesive properties of resin-modified glass ionomer cement (RMGIC) in human primary molars.
| Materials and Methods|| |
Selection of teeth
Thirty-six noncarious human primary molars extracted due to physiologic mobility and over retention were collected. The teeth were cleared of debris, scaled with an ultrasonic scaler and stored in physiological saline solution containing 0.1% thymol. The selected teeth were made sure to be free from cracks and any developmental anomalies.
Ozonated water preparation
Five mL of distilled water was sparged with ozone gas from an ozone-generating device (Eltech-DOZ200, Eltech Engineers, Mumbai, India) with a range of 300s (approximately 1000 mg/L) and ozonated water was obtained.
To evaluate the shear bond strength
Eighteen primary molars were sectioned in a mesiodistal direction using a diamond disk with a water coolant to obtain 36 specimens. The hemi-sectioned specimens were embedded in acrylic resin and ground with a polishing machine to create a flat superficial dentinal surface and were randomly divided into three groups, comprising 12 specimens each.
Dentin surfaces of Group I were treated with distilled water for 20 s. In Group II, 2% CHX cavity disinfectant (Consepsis, Ultradent Products. Inc., USA) [Figure 1], was applied with a mini brush tip, placed in contact for 20 s, and rinsed off for 15 s. Group III specimens were treated with freshly prepared ozonated water for 80 s and rinsed off for 15 s.
The dentin surface of each specimen was conditioned with polyacrylic acid cavity conditioner for 15 s, washed, and blotted dry.
A Teflon mold measuring 2 mm in diameter and 3 mm in height was used to build the RMGIC cylinders [Figure 2] for the three groups on the dentinal surface using a two-layer increment technique with each layer being light cured for 40 s. The specimens of the three groups were stored separately in distilled water for 24 h at room temperature.
|Figure 2: Resin-modified glass-ionomer cement cylinders built on treated dentin surface|
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Assessment of bond strength
The shear bond test was performed using a universal testing machine (Instron, USA) [Figure 3] at a cross-head speed of 1 mm/min in a compression mode using a blade parallel to the dentinal surfaces as the shearing element and the readings were noted. Further, the fractured specimens were observed under the stereomicroscope for cohesive or adhesive type of failure. The values obtained were calculated in megapascal (MPa) according to the area of adhesion and subjected to statistical analysis.
To evaluate microleakage
Eighteen primary molars were randomly divided into three groups corresponding to each cavity disinfectant to be used. Class-V cavities were prepared on the buccal and lingual surface of 18 primary molars to obtain 12 specimens for each group. Standardization of the cavities: The cavities were standardized with the help of Williams's periodontal probe at 3-mm length, 2-mm width, and 1.5-mm depth, according to Hall et al. criteria.
Cavity disinfection was performed as described previously.
The cavities of each specimen were conditioned with polyacrylic acid cavity conditioner for 15 s, washed, and blotted dry. All the cavities were restored with RMGIC, condensed and cured for 40 s. Furthermore, all the restorations were polished using a composite polishing kit and subsequently stored in the distilled water for 24 h at room temperature separately for all the three groups until further evaluation. The teeth were subjected to thermocycling. Temperatures used were 12°C + 2 and 60°C + 2. The restorations were subjected to 1500 cycles. Two coats of nail polish were applied to all tooth surfaces except for 1 mm around the restoration. The apices were sealed with wax. The teeth were immersed in 0.6% Rhodamine B dye and incubated at 37°C for 24 h.
| Statistical Analysis and Results|| |
The results were expressed as the mean ± standard deviation for analysis of bond strength one-way ANOVA for multiple group comparisons, followed by post hoc Tukey's test for group-wise comparison was used. Since the microleakage scores ranged between 0 and 1, group-wise comparison of microleakage scores was done using the Chi-square test.
Bond strength was the highest in the distilled water group [Table 1] and [Table 2] followed by ozone group and then by the CHX group, although these differences were statistically nonsignificant. Microleakage in cavities treated with 2% CHX was statistically greater than those treated with ozone [Table 3] and [Table 4], and the least with the ozone group.
|Table 1: Mean (mpa) shear bond strength values of the tested cavity disinfectants on dentin of primary molars|
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|Table 4: Group-wise comparisons of microleakage scores using the Chi-square test|
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| Discussion|| |
The lack of definitive and reliable assessment criteria to quantify residual affected dentin allows microorganisms to go undetected. The problem of bacteria remaining in a cavity is more pronounced by an increasing trend toward minimally invasive, tissue-saving dentistry in which the tooth structure is preserved to the greatest extent possible.
Residual bacteria can survive for more than a year and can proliferate even in the presence of a good seal. Adjunctive treatment with antibacterial agents could prevent the detrimental effects of residual bacteria, such as pulp damage, hypersensitivity, and recurrent caries (a major cause of restoration replacement). Hence, creating a biologic seal by eliminating residual bacteria while not affecting the adhesiveness of a restorative material can improve the longevity of restorations.
In the present study, the bond strength displayed by the CHX group was comparable to that of the distilled water and ozone groups [Graph 1]. This was in accordance with the studies of Say et al., and Soares et al. On the other hand, CHX showed higher microleakage when compared to ozonated water.
Meiers and Kresin  in anin vitro study, found that the use of cavity disinfection after tooth preparation and before the application of a dentin bonding agent could help to reduce the potential for residual caries. Elgamily et al., in anin vitro study investigated the antimicrobial efficacy of CHX gluconate disinfectant against Streptococcus mutans and concluded that cavity disinfectant could be used to improve the antimicrobial capacity of the material and help to decrease the secondary caries risk.
The application sequence of the disinfectant is another factor to be considered. Some clinicians prefer to apply the disinfectant after cavity preparation, before the acid etching/conditioning, whereas others prefer to apply after etching. Some clinicians also prefer to rinse off the disinfectant before the bonding procedure and others do not (Perdigao et al., 1994; Meiers and Kresin, 1996). Perdigao et al. (1994) applied the disinfectant after the smear layer removal, and they did not find any decrease in the shear bond strength to dentin. Cao et al. (1995) showed that the disinfectants decreased shear bond strength to dentin. However, the degree of decrease was related to the brand of adhesive and disinfectant. Consepsis was the only disinfectant that was not significantly different from the control. Gürgan et al. showed that the application of 2% Consepsis for 15 s and rinsing it off did not reduce the bond strength of the restoration to dentin. Hence, 15 s was chosen as the application time for the CHX group in the present study.
Treatment time for the ozone group was set at 80 s in the study in accordance with Polydorou et al., who showed that the antibacterial effect of ozone on S. Mutans was significantly higher when treated for 80 s compared to 40 s.
The results of this study indicate that using a cavity disinfectant of 2% CHX before conditioning and rinsing it off, does not affect the shear bond strength to primary dentin, in accordance with Meiers and Kresin  and Ricardo Vieira and da Silva.
Few studies have evaluated the influence of CHX on bond strength in the primary teeth,,, and their results comply with that of the present study. Previousin vitro andin vivo studies in permanent and primary teeth have shown that the application of CHX at concentrations ranging between 0.12% and 2%, before acid etching ,,, or after acid etching ,, did not have an adverse effect on the immediate bond strength between the dentinal substrate and polymeric material. Even though CHX group showed the least values of all groups, the bond strength values were within the normal range for RMGIC, and this was similar when the sealing ability was compared with the other two groups, CHX group showing more microleakage [Graph 2].
The reason that cavity disinfectants may affect the dentin bond of resin-modified glass-ionomers may be explained in the way that these cements attach to dentin. Traditional glass-ionomer cements bond primarily to the inorganic component (calcium) of tooth structure by a chelation reaction that is similar to the setting reaction of the material. This involves initial hydrogen bonding followed by the formation of metal ion bridges and is a true physicochemical bond. The development of an ion exchange layer that is formed between the glass-ionomer material and the tooth is very important in the prevention of microleakage into the dentinal tubules. A smooth, clean surface with good wettability is needed to obtain good adhesion between the tooth and the glass-ionomer restorative material. The polyacrylic acid removes the smear layer and surface contaminants at the same time as it alters the surface energy and exposes the mineralized tooth structure to the diffusion of the acid and the exchange of ions. In addition, there has been some evidence that, with resin-modified glass-ionomer materials, a micromechanical interlocking of the resin component forming a hybrid layer at the surface of the dentin also plays a role in surface adhesion., With regard to ozone, the mean shear bond strength values were higher than the CHX group but almost similar to the control group, and the differences were not statistically significant. Ozone group showed better sealing ability than the CHX group and control.
Since ozonated water was evaluated as a cavity disinfectant, it circumvents complications associated with its inhalation in the gaseous form. Magni et al. indicated that ozone gas did not compromise the mechanical properties of the adhesives (including Prime and Bond NT [Dentsply], Excite [Ivoclar-Vivadent], Syntac/Heliobond [Ivoclar-Vivadent], and Silorane System Adhesive [3M-ESPE]). When ozone gas was used to disinfect the cavity before a restoration, it had no influence on the immediate enamel and dentin bond strength. Cehreli et al. revealed that pretreatment with ozone improved the marginal sealing ability of the fissure sealants. This is in accordance with the current study where the ozone group has shown better sealing ability than the CHX and control group.
| Conclusion|| |
The application of ozone for cavity disinfection does not interfere with the bonding and sealing ability of RMGIC to primary tooth dentin. It is more compatible with RMGIC than CHX, and hence, can be considered for routine cavity disinfection. Long-termin vivo evaluations must be conducted to determine the practical application of ozonated water on mechanical and biologic sealing properties of adhesive materials on the primary teeth.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Gürgan S, Bolay S, Kiremitçi A. Effect of disinfectant application methods on the bond strength of composite to dentin. J Oral Rehabil 1999;26:836-40.
Manfro AR, Reis A, Loguercio AD, Pettorossi Imparato JC, Raggio DP. Effect of chlorhexidine concentration on the bond strength to dentin in primary teeth. Rev Odontol Ciênc 2010;25:88-91.
Okado A, Nikaido T, Gyo M, Shida K, Tagami J, Matin K. Potency of ozonated alkali-ion water in inactivating cariogenic bacteria. Int Chin J Dent 2007;7:79-85.
Polydorou O, Pelz K, Hahn P. Antibacterial effect of an ozone device and its comparison with two dentin-bonding systems. Eur J Oral Sci 2006;114:349-53.
Hall LH, Cochran MA, Swartz ML. Class 5 composite resin restorations: Margin configurations and the distance from the CEJ. Oper Dent 1993;18:246-50.
Türkün M, Türkün LS, Ergücü Z, Ateş M. Is an antibacterial adhesive system more effective than cavity disinfectants? Am J Dent 2006;19:166-70.
Say EC, Tarim B, Soyman M, Gulmez T.In vitro
effect of cavity disinfectants on the bond strength of dentin bonding systems. Dent Mater 2004;35:56-60.
Soares CJ, Pereira CA, Pereira JC, Santana FR, do Prado CJ. Effect of chlorhexidine application on microtensile bond strength to dentin. Oper Dent 2008;33:183-8.
Meiers JC, Kresin JC. Cavity disinfectants and dentin bonding. Oper Dent 1996;21:153-9.
Elgamily HM, El-Sayed HS, Abdelnabi A. The antibacterial effect of two cavity disinfectants against one of cariogenic pathogen: Anin vitro
comparative study. Contemp Clin Dent 2018;9:457-62.
] [Full text]
Vieira Rde S, da Silva IA Jr. Bond strength to primary tooth dentin following disinfection with a chlorhexidine solution: Anin vitro
study. Pediatr Dent 2003;25:49-52.
Hebling J, Pashley DH, Tjäderhane L, Tay FR. Chlorhexidine arrests subclinical degradation of dentin hybrid layers in vivo
. J Dent Res 2005;84:741-6.
Ersin NK, Candan U, Aykut A, Eronat C, Belli S. No adverse effect to bonding following caries disinfection with chlorhexidine. J Dent Child (Chic) 2009;76:20-7.
Perdigao J, Denehy GE, Swift EJ Jr. Effects of chlorhexidine on dentin surfaces and shear bond strengths. Am J Dent 1994;7:81-4.
Carrilho MR, Carvalho RM, de Goes MF, di Hipólito V, Geraldeli S, Tay FR, et al.
Chlorhexidine preserves dentin bond in vitro
. J Dent Res 2007;86:90-4.
Stanislawczuk R, Amaral RC, Zander-Grande C, Gagler D, Reis A, Loguercio AD, et al.
Chlorhexidine-containing acid conditioner preserves the longevity of resin-dentin bonds. Oper Dent 2009;34:481-90.
Brackett WW, Tay FR, Brackett MG, Dib A, Sword RJ, Pashley DH, et al.
The effect of chlorhexidine on dentin hybrid layers in vivo
. Oper Dent 2007;32:107-11.
Mount GJ. Adhesion of glass-ionomer cement in the clinical environment. Oper Dent 1991;16:141-8.
Erickson RL, Glasspoole EA. Bonding to tooth structure: A comparison of glass-ionomer and composite-resin systems. J Esthet Dent 1994;6:227-44.
Carvalho RM, Yoshiyama M, Horner JA, Pashley DH. Bonding mechanism of VariGlass to dentin. Am J Dent 1995;8:253-8.
Magni E, Ferrari M, Papacchini F, Hickel R, Ilie N. Influence of ozone application on the repair strength of silorane-based and ormocer-based composites. Am J Dent 2010;23:260-4.
Cadenaro M, Delise C, Antoniollo F, Navarra OC, Di Lenarda R, Breschi L, et al.
Enamel and dentin bond strength following gaseous ozone application. J Adhes Dent 2009;11:287-92.
Cehreli SB, Yalcinkaya Z, Guven-Polat G, Cehreli ZC. Effect of ozone pretreatment on the microleakage of pit and fissure sealants. J Clin Pediatr Dent 2010;35:187-90.
[Figure 1], [Figure 2], [Figure 3]
[Table 1], [Table 2], [Table 3], [Table 4]