Effect of calcium hydroxide intracanal dressing on the bond strength of a resin-based endodontic sealer

Abstract

The aim of this in vitro study was to evaluate the bond strength of Epiphany™ resin-based sealer to dentin walls after placement of calcium hydroxide [Ca(OH) 2 ] dressings. Fifteen extracted single-rooted human teeth were instrumented using 2.5% NaOCl + EDTA as irrigants. The teeth were randomly assigned to 3 groups (n=5), according to the intracanal dressing: G1= Ca(OH) 2 + saline; G2= Ca(OH) 2 + 2% chlorhexidine gluconate (CHX) gel; and G3= saline (control). After 10 days of storage in 100% humidity at 37°C, the dressings were removed and the root canals were filled with Epiphany™ sealer. After additional 48 h of storage, the specimens were sectioned transversally into 2-mm-thick discs. Push-out tests were performed (1 mm/min, Instron 4411) and the maximum loads at failure were recorded in MPa. One-way ANOVA and Newman-Keuls tests showed a statistically significant decrease in bond strength when a Ca(OH) 2 dressing was used before root canal filling with Epiphany™ (G1= 10.18 ± 1.99 and G2= 9.98 ± 2.97) compared to the control group (13.82 ± 3.9) (p< 0.05). It may be concluded that the use of Ca(OH) 2 as an intracanal dressing material affected the adhesion of Epiphany™ to the root canal walls, but even though the values were within the acceptable range found in the literature.

Calcium hydroxide intracanal dressing removal with different rotary instruments and irrigating solutions: a scanning electron microscopy study

“…of CH residues may interfere with sealing ability of endodontic sealers (8,9), and affect the adhesion of endodontic sealers to the canal walls (10). Moreover, there is evidence that these residues may react with zinc oxide and eugenol-based cements, forming calcium eugenolate, which hinders the penetration of cement into the dentin tubules (8).…”

Eficácia da irrigação ultrassônica passiva na remoção de hidróxido de cálcio

“…Entretanto, para excluir qualquer interferência negativa entre medicamento e material obturador, e para garantir a qualidade da obturação, todos os resíduos de Ca(OH) 2 devem ser retirados das paredes do canal antes da obturação [4][5][6][7][8][9][10][11][12] .…”

Efficacy of NiTi rotary instruments in removing calcium hydroxide dressing residues from root canal walls

“…5 However, before the root canal can be filled, the dressing on the canal must first be removed. 6 Calcium hydroxide residues on the canal walls interfere negatively in endodontic treatment prognosis, 7 influence dentine bond strength, 8 affect the adhesion of the endodontic filling material to the root canal walls 9 and the penetration of sealers into dentinal tubules, 10 and react chemically with the sealer, interfering with its physical properties. 11,12 Several techniques have been proposed to remove the calcium hydroxide dressing from the root canal system, including the use of endodontic hand files, 13 sonic activation, 14 passive ultrasonic irrigation, 6,15 the CanalBrush System 6 and nickel-titanium rotary instruments.…”