Effect of Sodium Hypochlorite Treatment on Remineralization of Human Root Dentine in vitro

Abstract

Dentine consists simplified of mineral and of several organic components. Sodium hypochlorite (NaOCl) is a well-known nonspecific proteolytic agent capable to remove organic material. The aim of this study was to investigate the influence of organic material removal from artificial dentine lesions by means of NaOCl pretreatment on subsequent remineralization with and without fluoride. Human root dentine samples were demineralized in an acidic gel (pH = 5) at 37°C for 2 weeks. After 2 min of pretreatment with a 0.4, 2 or 10% NaOCl solution, the samples were remineralized in a 20 mM HEPES buffer (pH = 7) containing 1.5 mMCa²⁺ and 0.9 mM phosphate with or without addition of 10 ppm F^– as NaF at 37°C for 8 days. Mineral profiles were assessed by means of transversal micro-radiography after diol treatment to avoid shrinkage caused by drying. In a separate experiments the dentine contraction caused by 10% NaOCl was assessed. The contraction (negligible for sound dentine) was found to be about 12% for the lesions. The remineralization results showed that pretreatment with a 10% NaOCl solution for 2 min, increased lesion remineralization. After NaOCl treatment, the amount of accumulated mineral increased by about 27% without F in the remineralization solution, and by about 4% with 10 ppm in solution. The in vitro results suggest that removal of organic materials from dentine lesions is an interesting approach to enhance remineralization.

Evaluation of Smear Layer Removal and Calcium Ions Concentration in Intraradicular Dentin Treated with Apple Vinegar (SEM Study)

“…The highest mean calcium content that was recorded in group V a (Saline) compared to group V b (did not receive any irrigation) could be explained by the variable effect of NaOCl as irrigating solution on mineral content of root dentin, where it has been reported that treatment with sodium hypochlorite may causes mineral accumulation in human root dentin (33) . Moreover, it has been demonstrated that the use of 2.5% sodium hypochlorite as irrigation solution, either alone or combined with a 17% EDTA solution, significantly increases the Ca/P ratio of root dentin (18) .…”

Remineralization of Advanced Root Dentin Lesions in vitro

“…From the observation that the surface layer did not hypermineralize we conclude that the tubules remained open and are available for ion transport. Other investigators [Inaba et al, 1996] have shown rapid hypermineralization after hypochlorite treatment, which removed the organic content or lining of the tubules, thus improving crystal growth conditions.…”

Effects of Root Canal Irrigants on the Push-out Strength and Hydration Behavior of Accelerated Mineral Trioxide Aggregate in its Early Setting Phase

“…In this regard, Kogan et al (6) investigated the effects of various additives on setting properties of MTA and showed that MTA mixed with NaOCl gel improved the setting process. NaOCl is also known as a halogenated compound that can cause mineral accumulation in human root dentin (19). With respect to this, Uyanik et al (20) reported that the sealing ability of furcal perforation repaired with MTA was affected by exposure to the irrigation regimens and the samples irrigated with NaOCl had the lowest leakage values.…”