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Title Chlorhexidine (CHX) May Improve Bond Longevity and Reduce Failure of Resin Composites
Clinical Question Does pretreatment with chlorhexidine (CHX) improve bond longevity in patients with composite restorations?
Clinical Bottom Line Pretreatment with chlorhexidine does improve the microtensile strength of the bond in resin composites, but more studies are needed to determine if the results are clinically significant and if CHX extends the life of the restoration. Pretreatment with chlorhexidine has been found to be potentially deleterious only in self-etching adhesive systems.
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 26957786Dionysopoulos/201614 studies that used CHX as pre-treatmentSystematic review of randomized trials
Key resultsBased on the included studies, the author concluded that the use of CHX improved surrogate measures of bond longevity, such as bond strength or stability of the hybrid layer, when bonding to dentin. Most studies included in this systematic review support the conclusion that there are indeed improved results when applying CHX for 60 seconds after etch-and-rinse systems. Those studies showed that pretreatment with CHX exhibited lower bond strength reduction than the control groups. Bond strength reduction varied in CHX treated groups ranging from 0%-84.9%. The author concluded that there is sufficient evidence that CHX can significantly inhibit matrix metalloprotease (MMP) degradation of collagen, but currently there is not enough evidence to determine if the result is clinically significant; more clinical studies are needed.
#2) 20662916Ricci/201013 children with at least one pair of contralateral primary molars with occlusal cariesIn vivo study
Key resultsThis study measured the microtensile bond strength over time in children with at least one pair of contralateral primary molars with occlusal carious lesions. The teeth were collected after physiological exfoliation. The authors found that within the first period of measure (1-5 months) the microtensile bond strength had significantly deteriorated in the control group (by 30.6%) while the CHX-treated group had only deteriorated by 7.4%, which had no significant difference from the immediate bond strength. Furthermore, the authors found that there was not a significant decrease in microtensile bond strength in the CHX-treated group until the 7-12 month period, while the controls started to show signs of significant deterioration within the 1-5 month period. After 18-20 months, the microtensile bond strength of the control group had decreased by 56.5% and the CHX-treated group only 37.0%. However, clinical examination revealed no marginal gaps or signs of leakage.
#3) 19678455Stanislawczuk/200942 caries-free extracted molarsIn vitro lab study
Key resultsThis study compared groups that were etched and bonded using conventional acid etchant, etched and bonded using a CHX-containing acid, and etched and bonded exactly like the first group, but CHX was applied for 60 seconds after etching with the conventional etchant. Outcomes were the amount of nanoleakage and microtensile bond strength. A lack of nanoleakage was correlated with increased microtensile bond strength (R2=0.87, p=0.0001). After 6 months of water storage the CHX-treated groups (either CHX alone or acid containing CHX) had no significant change in bond strength and also had significantly lower infiltration of silver particles into dentinal tubules. However, there was no significant difference between the two CHX treatment groups, indicating that the method of CHX application may not play a role. The authors noted that the application of CHX after etching may increase the surface energy of the etched dentinal surface and thereby increase the wettability of the primer, which could further improve bond strength.
Evidence Search ("chlorhexidine"[MeSH Terms] OR "chlorhexidine"[All Fields]) AND ("composite resins"[MeSH Terms] OR ("composite"[All Fields] AND "resins"[All Fields]) OR "composite resins"[All Fields] OR ("resin"[All Fields] AND "composite"[All Fields]) OR "resin composite"[All Fields]) AND bond[All Fields] AND ("longevity"[MeSH Terms] OR "longevity"[All Fields])
Comments on
The Evidence
In the Dionysopoulos 2016 systematic review, meta-analysis not performed due to the variation in experimental methods, reagents, and bonding protocols used. Only 14 studies used CHX as a pre-treatment, and only those results were considered for the discussion of this CAT. The reported contrary results in this study specifically applied to a small number of studies that used CHX as a pre-treatment in self-etch adhesives. In the Ricci 2010 study, microtensile strength was used as a surrogate measure for bond strength. Due to limitations on controlling the exfoliation of the primary teeth, sample sizes varied for the aging period groups (e.g., 1-5 months, 10-12 months), and the study would have been more valid with larger sample sizes in each aging category. Additionally, these studies were done on primary teeth, presumably to avoid any risk of harm to the permanent dentition, which affects the generalizability of the results to permanent teeth due to minor differences in the structure of primary teeth. This study replicates clinical situations accurately due to exposure of the restorations to the oral cavity for an extended period of time. However, this also introduces factors that the researchers were unable to control that may play a role in the aging of the restoration, such as variation in diet and oral hygiene. In the Stanislawczuk 2009 study, samples were stored in water for 6 months, which does not mimic the clinical environment to which a restoration is exposed. Surrogate measures of nanoleakage and microtensile strength were used in this study to infer bond longevity. Experiments in this study also compared the use of CHX in the etchant with CHX treatment after etching and rinsing.
Applicability The studies focused on pretreatment with chlorhexidine after using an etch and rinse system. Chlorhexidine is relatively inexpensive and its use adds only approximately 60 seconds to the practitioner's time for restoration, with no observable harmful effects. The evidence suggests that chlorhexidine is a feasible option to increase restorative success for patients.
Specialty/Discipline (Public Health) (General Dentistry) (Pediatric Dentistry) (Restorative Dentistry) (Basic Science)
Keywords Microtensile bond strength, bond longevity, chlorhexidine, nanoleakage, adhesive systems
ID# 3128
Date of submission: 12/28/2016spacer
E-mail YatesD@livemail.uthscsa.edu
Author Daniel Yates, MS
Co-author(s) e-mail
Faculty mentor/Co-author Karen Troendle, DDS
Faculty mentor/Co-author e-mail TROENDLE@uthscsa.edu
Basic Science Rationale
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