Influence of Exposing Root Canal Dentin to Calcium Hydroxide on Its Flexural Strength

Diatri Nari Ratih(1*),

(*) Corresponding Author


Calcium hydroxide has been used extensively in endodontic treatments, for instance as an intra-canal dressing; however, the exposure of root canal dentin to calcium hydroxide may affect its flexural strength and could have important clinical implications for endodontic treatment. The purpose of this in vitro study was to investigate the influence of calcium hydroxide on the flexural strength of root canal dentin.
Seventy-two extracted single-rooted human mandibular premolars were used in this study. Each tooth was instrumented using crown-down technique and was irrigated using sterile saline. The teeth were assigned into three groups of 24 each. The prepared root canal system of each tooth was filled with calcium hydroxide mixed with sterile saline (group 1), a calcium hydroxide commercially available product (UltraCal®) (group 2) or saline solution (group 3, as control). The apices and access opening were sealed using composite resin, and the teeth were immersed in artificial saliva. After 7, 14 and 30 days of immersion, the inner root canal dentin of 8 teeth respectively from each group were sectioned to create dentin bars (1 X 1 mm, with 7 mm in length). Each dentin bar then was subjected to a three-point bending flexural test using MTS (Universal Testing Machine). Data gathered were then analyzed using two-way ANOVA, followed by Tukey’s test with the level of significance of 95%. The results showed that exposure to calcium hydroxide either using calcium hydroxide mixed with sterile saline or UltraCal® for 14 and 30 days can reduce flexural strength of root canal dentin compared to control group (p<0.05). In contrast, after 7 days exposure, there was no significantly different of flexural strength between three groups (p>0.05).   It can be concluded that calcium hydroxide reduced the flexural strength of root canal dentin. The longer the exposure to calcium hydroxide would produce a greater effect on flexural strength of root canal dentin.   


Calcium hydroxide; root canal dentin; flexural strength; endodontic treatment

Full Text:



Ruddle CJ. 2006. Pulp development, structure and function. In: Cohen S, Burns RS, Ed. Path- ways of The Pulp 9th ed. Mosby: 386-425.

Mohamadi FA. 2005. Calcium hydroxide: A Re- view. Int Dent J, 55: 293-301.

Yucel AC, Aksoy A, Guvenc D. 2007. The pH changes of calcium hydroxide mixed with six different vehicles. Oral Surg Oral Med Oral Path Oral Rad & Endod, 20: 256-62.

Sathorn C, Parashos P, Messer H. 2007. Antibac- terial efficacy of calcium hydrolysis intra-canal dressing: A systematic review and meta-analy- sis. Int Endod J, 40: 2-10.

Poorni S, Miglani R, Srinivasan MR, Indira R. 2009. Comparative evaluation of the pH of calcium hydroxide mixed with five different vehicles:An in vitro study. India J Dent Res, 20: 17-20.

Tatsua CT, Morgan LA, Baumgartner C, Adey J. 1999. Effect of calcium hydroxide and four irrigation regimens on instrumented and uninstrumented canal wall topography. J Endod, 25:93-6.

Marending M, Stark WJ, Brunner TJ, Fisher J, Zehnder M. 2009. Comparative assessment of time-related bioactive glass and calcium hydrox- ide effects on mechanical properties of human root dentin. Dent Traumatol, 25: 126-9.

Kawamoto R, Kurokawa H, Takubo C, Shimamu- ra Y. 2008. Change in elastic modulus of bovine dentine with exposure to a calcium hydroxide paste. J Dent, 8: 315-20.

Doyon GE, Dumsha T, Fraunhofer JA. 2005. Frac- ture resistance of human root dentin exposed to intracanal calcium hydroxide. J Endod, 31:895-7

Lee KW, Williams MC, Camps JJ. 2002. Adhesion of endodontic sealers to dentin and gutta-per- cha. J Endod, 28: 684-8.

Grigoratos D, Knowles J, Ng YL, Gulabivala K.2001. Effect of exposing dentine to sodium hypochlorite and calcium hydroxide on its flexural strength and elastic modulus. Int Endod J, 34: 113-9.

Soares CJ, Santana FR, Silva NR, Petra JC, Perei- ra CA. 2007. Influence of the endodontic treat- ment on mechanical properties of root dentin. J Endod, 33: 603-6.

Plotino G, Grande NM, Bedini R, Pameijer CH, Somma F. 2007. Flexural properties of endodon- tic posts and human root dentin. Dent Mater,23: 1129-35.

Dietschi D, Duc O, Krejci I, Sadan A. 2007. Bio- mechanical considerations for the restoration of endodontically treated teeth: A systematic review of the literature-part 1. Composition and micro and macrostructure alterations. Quintes- sence Int, 38: 733-40.

Machnick TK, Torabinejad M, Munoz CA, Sha- babang S. 2003. Effect of MTAD on flexural strength and modulus of elasticity of dentin. J Endod, 29: 747-50.

Leonardo MR, Hernandez M, Silva L, Filho M. 2006. Effect of a calcium hydroxide-based root canal dressing on periapical repair in dogs: A histological study. Oral Surg Oral Med Oral Path Oral Rad & Endod 102: 680-5.

Morgana EV, Zilio DM, Ferraz CC, Zaia AA, Filho FJ, Gomes BP. 2009. Concentration of hydrogen ions in several calcium hydroxide pastes over dif- ferent periods of time. Braz Dent J, 20: 382-8.


Article Metrics

Abstract views : 153 | views : 54


  • There are currently no refbacks.





website statistics


View My Stats