Effect of Chlorhexidine Treatment Prior to Fiber Post Cementation on Long-Term Resin Cement Bond Strength

Abstract

The purpose of this study was to evaluate the push-out bond strength of two different adhesive cements (total etch and self-adhesive) for glass fiber post (GFP) cementation in simulated, long-term service (thermocycling) when the root canal is treated with chlorhexidine before cementation. One hundred twenty premolar specimens with a single root canal were selected, endodontically treated, and shaped for GFP cementation (n=120). The specimens were randomly placed into one of 12 groups (10 specimens each) according to cement (T = total-etch RelyX ARC or S = self-adhesive RelyX Unicem), treatment with chlorhexidine (N or Y: without or with), and number of thermal cycles (00, 20, or 40: 0, or 20,000 or 40,000 cycles): 1. TN00, 2. TN20, 3. TN40, 4. TY00, 5. TY20, 6. TY40, 7. SN00, 8. SN20, 9. SN40, 10. SY00, 11. SY20, 12. SY40. The root of each specimen was cut perpendicular to the vertical axis, yielding six 1.0 mm-thick sections. A push-out bond strength test was performed followed by statistical analysis using a factorial analysis of variance. Pairwise comparisons of significant factor interactions were adjusted using the Tukey test. Significant differences of push-out bond strengths were found in the four main effects (resin cement [ p<0.0001], treatment with chlorhexidine [ p<0.0001], number of cycles [ p<0.0001], and root third [ p<0.0001]) and all interactions ( p<0.05 for all). Both resin cements produced higher bond strength in the cervical third followed by the middle third, and lower values were detected in the apical third. Additionally, the results suggest that the use of an additional disinfection treatment with chlorhexidine before the cement application produced the highest push-out bond strength regardless of root third. Further, the thermocycling simulation decreased the bond strength for both resin cements long-term when the chlorhexidine was not applied before cementation. However, when the root canal was treated with chlorhexidine and the fiber post was cemented with self-adhesive cement, the bond strength increased after 0, 20,000 and 40,000 cycles.

Effect of carbodiimide and chlorhexidine on the bond strength longevity of resin cement to root dentine after radiation therapy

“…Dentine treatment with chlorhexidine resulted in intermediate adhesive interface adaptation (Fig. ) and bond strength values after 10 months when compared to saline solution (lowest bond strength values) and EDC (higher bond strength values), due its action as a nonspecific inhibitor of metalloproteinase, preventing the degradation of the adhesive interface (Hebling et al , Cecchin et al , Shafiei et al , Durski et al ). However, the mechanism of inhibition of metalloproteinase by chlorhexidine occurs through a collapsible electrostatic bonding to collagen, which added to its solubility in water can lead to its slow diffusion from the collagen matrix, resulting in loss of metalloproteinase inhibitory action within months (Ricci et al , Shafiei et al ), unlike the EDC mechanism of inhibition, which prevents the collagen polypeptides from being unwound by the metalloproteinase, and inactivate the catalytic site of the proteases, creating a new peptide bond, thus being more durable (Scheffel et al , Shafiei et al , Alonso et al ).…”

“…Therefore, the use of substances that have the potential to inhibit the enzymes that degrade collagen fibrils may contribute to the maintenance of the durability of the adhesive interface (Mazzoni et al 2014, Alonso et al 2018. One of the substances used in order to maintain the stability of the adhesive interface is chlorhexidine digluconate, which acts as a metalloproteinase inhibitor (Hebling et al 2005, Zhou et al 2013, Mazzoni et al 2014, Durski et al 2018 helping to maintain long-term bond strength values (Ricci et al 2010, Durski et al 2018. Another strategy that has been studied to improve the quality and stability of the adhesive interfaces is to stimulate the formation of cross-links between the collagen molecules, thereby increasing the resistance of the collagen fibres to degradation (Scheffel et al 2015).…”

Aspectos relevantes para el éxito en la cementación de los pernos fibra de vidrio

“…Los resultados sugieren que el cemento autoadhesivo tiene una mayor fuerza de unión en comparación con el cemento de acondicionamiento completo, y cuando se trata con clorhexidina antes de la cementación, esos números son más altos, inmediatamente y a largo plazo. (38) Rodrigueset al (39) evaluaron la fuerza de unión de postes de fibra con diferentes protocolos de cementación: sistema adhesivo acondicionador ácido de 3 pasos en combinación con un cemento de resina dual; un sistema adhesivo universal asociado a un cemento de resina dual; y un cemento de resina autoadhesivo dual. Los diferentes protocolos de cementación adhesiva no influyeron en la fuerza de unión del perno de fibra a la dentina en la misma profundidad.…”

Effect of irrigation protocols on smear layer removal, bond strength and nanoleakage of fiber posts using a self-adhesive resin cement

“…Contrasting advantages and disadvantages, the literature is conflicting when chlorhexidine is used prior to fiberglass posts cementation. On one side, some studies show a reduction in BS or even no effect, on the other hand, there are studies that have obtained an increase in adhesion for immediate results and for the long term [ 6 9 13 14 15 16 17 18 ]. Chlorhexidine has been indicated as an alternative irrigator due to its antimicrobial activity, biocompatibility, and substantivity and it does not interfere with the collagen of the organic matrix of the root dentin, thus maintaining the quality of the substrate [ 6 19 20 21 ].…”