Effects of Different Chlorhexidine Formulations on Shear Bond Strengths of Orthodontic Brackets

Abstract

Objective: To test the hypothesis that the application of different chlorhexidine formulations to the etched enamel will not affect shear bond strength (SBS). Materials and Methods: Forty-four freshly extracted human premolars were collected and stored in distilled water. The teeth were etched with 37% phosphoric and were rinsed and dried. The teeth then were divided into four equal groups. While Group 1 served as a control, Groups 2 to 4 were treated before bonding with a chlorhexidine formulation that included solution (2%), gel (1%), and mouthwash (0.2%). Orthodontic brackets were bonded with Transbond XT (3M Unitek, Monrovia, Calif). Bond strength results were evaluated with the use of one-way analysis of variance (ANOVA) (P Ͻ .05) and post hoc tests. Modes of failures were verified by means of scanning electron microscopy. Results: Although no statistically significant difference was observed between Groups 1 and 4 (P Ͼ .05), both were statistically superior to Groups 2 and 3 (P Ͻ .05). In this in vitro study, the observed measures for Groups 2 and 3 (14.5-10.6 MPa) were lower than those for Groups 1 and 4 (27.3-24.9 MPa), but these values were much higher than those required for clinical use (6-8 MPa). Conclusion:The hypothesis is rejected. The application of chlorhexidine mouth rinse before bonding had no significant effect on the SBS value, and the application of chlorhexidine solution and gel significantly decreased SBS. (Angle Orthod. 2008;79:312-316.)

Effects of different chlorhexidine pretreatments on adhesion of metal brackets in vitro

“…Most of the studies testing the effects of CHX applications on bracket adhesion have used the antibacterial agent following etching of enamel with a similar principle to cavity disinfection [10-14,16]. Parallel to this idea, CHX was added to the bonding agent and applied on the etched enamel surface and photo-polymerized in order to prolong its release.…”

“…Numerous studies have investigated the possible effects of different CHX applications on the adhesion of brackets. CHX was tested in all three forms under following conditions: before acid etching without subsequent surface cleaning; after enamel etching mixed with bonding agent; after enamel etching alone, without additional bonding agent; after enamel etching prior to photo-polymerization of the bonding agent; after enamel etching following the photo-polymerization of the bonding agent and mixed with bonding agent on hydrophilic primer applied etched enamel [10-16]. No adverse effect was reported when CHX with low concentrations was applied prior to acid etching but controversial results were reported following applications after acid etching where only mixing CHX varnish with the bonding agent was agreed to be a safe application by the researchers [10,11].…”

“…Moreover, there is no manufacturer instruction clarifying the appropriate mode of application and the state of bonding area prior to bracket placement, which is directly influential on persistence of bacterial suppression. Theoretically, adhesion might get affected by the presence of CHX on the enamel surface depending on its form and concentration [10,16]. To test this question, the aim of this present study was to investigate the influence of various pre-treatments with CHX applied according to manufacturer instructions on adhesion of brackets prior to bracket placement and observe the failure types following debonding.…”

Ağiz Sağliği Bi̇li̇nci̇ Ve Ortodonti̇ Hastalarinin Ağiz Sağliğinin Geli̇şti̇ri̇lmesi̇

“…Ortodontik tedavi gören bireylerin sakız çiğnemesi önerilmediğinden pastillerin kullanımı daha yararlı bulunmaktadır. 67 Sengun ve ark. 68 sabit ortodontik tedavi uygulanan vakalarda xylitol pastillerin plak pH'ına etkisini değerlendirmişler ve sonuç olarak olası dental çürüklerin önlenmesi amacıyla bu preparatın kullanılmasını tavsiye etmişlerdir.…”

Does chlorhexidine affect the shear bond strengths of orthodontic brackets?

“…Furthermore there are mouthwash and solution forms of CHX. 23 A previous in vitro study 23 assessed the effects of various CHX applications on the shear bond strength (SBS) of orthodontic bracket adhesives. The aim of the present in vitro study was to evaluate the effect of 1% CHX gel on the SBS of two different orthodontic primers (Transbond XT and Transbond Plus Self-Etching Primer, both from 3M Unitek, Monrovia, CA, USA).…”