The effect of retreatment procedure on the pH changes at the surface of root dentin using two different calcium hydroxide pastes

Abstract

Aim:To compare pH changes at the cervical, middle and apical surfaces of root dentin in retreated and non- retreated teeth, after canal obturation with two different calcium hydroxide pastes.Materials and Methods:After instrumentation of 55 extracted teeth, three cavities with 0.75 mm depth and 1.5 mm in diameter were drilled at buccal root surface. The teeth were randomly divided into five groups. Canals in the first two groups were filled with either mixture of calcium hydroxide and saline solution and calcium hydroxide and 2% chlorhexidine (CHX). In the third and fourth groups canals were first obturated with gutta-percha and AH26 sealer, and then materials were removed. After 2 days canals were filled with two different calcium hydroxide pastes similar to the first and the second groups. The pH was measured in the prepared cavities at 1, 3, 7 and 14 days.Results:In the non-retreated groups, pH at the surface of the roots was significantly higher in comparison to the retreated ones (P value < 0.001). pH values were significantly higher in the non-retreated teeth filling with calcium hydroxide and saline solution (P value < 0.001).Conclusion:Regarding to the little pH changes at the surface of dentin in retreated teeth, the hydroxyl ions cannot penetrate into the dentinal tubules. Thus, to achieve higher pH at the root surface in retreated teeth, it is clinically advisable to remove more dentin from the inner walls and to use normal saline as a vehicle for calcium hydroxide rather than acidic pH materials.

Diffusion of calcium hydroxide through dentinal tubules of retreated root canals: An in vitro study

“…Kazemipoor et al ,[ 11 ] have stated that the difficulties which are more challenging in the retreated canals are the openings of dentinal tubules which may be blocked with residual sealer and gutta-percha. This phenomenon can have an influence on the diffusion and penetration of hydroxyl ions into the dentinal tubules.…”

Assessment of calcium ions diffusion and pH measurements of three intracanal medicaments through dentinal tubules (in vitro comparative study)

“…This study sheds light on the comparison of pH measurement & calcium ions release measurement of three intracanal medicaments Ca(OH)2, Proroot Mineral Trioxide Aggregate and Biodentine at different studied periods (1,2,7,15,30, 45 and 60) days.…”

“…The remaining bacteria in the root canal after instrumentation have been shown to proliferate between appointments. Intra canal medicament is also well-established method for inhibition of external root resorption and stimulation of periapical healing in traumatized teeth (1) .…”

Effects of aPeganum harmala(Zygophyllaceae) preparation for root canal disinfection

“…E. faecalis is a Gram‐positive coccus, with the ability to form biofilms, and which are often isolated from root canals of teeth having persistent periapical lesions (Botelho et al, ; Veras et al, ). The manipulation of mechanical instruments does not effectively remove all the microorganisms from the root canal spaces, and consequently an endodontic irrigant or medicament should be applied in clinical practice as a necessary adjunct to mechanical preparation to promote the quality of the cleansing and shaping of the root canal space (Kazemipoor et al, ).…”

“…An ideal irrigating regimen should be highly effective, nontoxic, nonallergenic, and retain its effectiveness adjacent to dental hard tissue (Zehnder, 2006). Over time, a variety of synthetic antimicrobial agents have been introduced for disinfection of the root canal system, but none of these regimens meets all the requirements for an ideal irrigant (Kazemipoor, Tabrizizadeh, Dastani, & Hakimian, 2012).…”