Effects of calcium hydroxide on physical and sealing properties of canal sealers.
OBJECTIVE
To investigate whether Ca(OH)2 in four different agents alters the physical properties (Exp. I) and sealing ability (Exp. II) of root canal sealers.


METHODS
(Exp. I) Calcipex (Nippon Sika-Yakuhin, Shimonoseki, Japan), Vitapex (Neo-Dental, Tokyo, Japan), Calkyl (Showa Yakuhin, Tokyo, Japan), and Ca(OH)2 were used as Ca(OH)2 agents. Four sealers were tested for flow, working time, setting time, and film thickness: Canals (Showa Yakuhin), Canals-N (Showa Yakuhin), Ketac -Endo (Espe, Seefeld, Germany), and Sealapex (Kerr, Romulus, MI, USA). Each Ca(OH)2 agent was added to 10 vol.% of each sealer, and the mixture and controls without a Ca(OH)2 agent were tested according to ISO specifications. Measurements were compared using Student's t-tests (P < 0.05). (Exp. II) After removing Ca(OH)2 agents applied to the root canals of 100 extracted human teeth, canals were filled with sealer. Controls were filled with each sealer without Ca(OH)2 agents. Sealing ability was evaluated using distance of dye penetration from the apices. Dye penetration data were compared using analysis of variance and post hoc Newman-Keuls test (P < 0.05).


RESULTS
Ca(OH)2 agents influenced the physical properties of the sealers. Flow and setting time met ISO requirements, but film thickness and working time did not. Apical sealing ability of all four sealers was influenced by Ca(OH)2 agents. The sealing ability of Sealapex improved with all Ca(OH)2 agents. The physical and sealing abilities varied among the other sealers.


CONCLUSIONS
Contact with Ca(OH)2 agents left on the canal wall caused considerable changes to the sealing ability of sealers.
Department of Periodontics and Endodontics, Tsurumi University School of Dental Medicine, Tsurumi-ku, Yokohama, Japan. hosoya-n@tsurumi-u.ac.jp
N
N
Hosoya
H
H
Kurayama
F
F
Iino
T
T
Arai
D002126:Calcium Hydroxide / Q000009:adverse effects*; D004396:Coloring Agents; D003763:Dental Leakage / Q000175:diagnosis / Q000209:etiology*; D004347:Drug Interactions; D005899:Glass Ionomer Cements; D006801:Humans; D012387:Root Canal Filling Materials / Q000009:adverse effects*; D012459:Salicylates; D015035:Zinc Oxide-Eugenol Cement
D004396:Coloring Agents; D005899:Glass Ionomer Cements; C074934:Ketac Endo; D012387:Root Canal Filling Materials; D012459:Salicylates; D015035:Zinc Oxide-Eugenol Cement; C112894:canals sealer; C055601:Sealapex; D002126:Calcium Hydroxide