Risk Assessment of the Toxicity of Solvents of Gutta-Percha Used in Endodontic Retreatment

By Chutich MJ, Kaminski EJ, Miller DA, Lautenschalager EP

Date: 09/1998
Journal: JOE

Summary: 

•Purpose: to determine how much of a particular solvent used may become available to the tissues surrounding the tooth structure, and if the controlled use and the amount of such solvent poses a significant health risk to the patient.

•N=  55 human single-canal, extracted human teeth with completely formed root apices

•Materials/Methods:

• The teeth were secured to the receptacle via the acrylic collar to establish a hermetic seal between the acrylic collar and the inner walls of the polypropylene test tube. All canals were prepared (step-back) to a minimum file size 40.

•Obturated teeth (40) were randomly selected for placement into one of the three experimental groups of one of three organic solvents(10\GP): chloroform, xylene, or halothane. Two groups of teeth served as positive (n=15) \ negative controls (10).

•positive controls (used to establish the ability of solvent to pass through the apical foramen).

•The sealed test tube was weighed. Total amount of solvent was recorded.

• Most highlighted Results:

Table

1.The mean weight of apically extruded solvent was 0.32 mg for the chloroform group, 0.35 mg for the halothane group, and 0.22 mg for the xylene group.

2.Data obtained from the positive control groups demonstrated the ability of the solvents to pass through the apical foramen.

3.The increase detected in the experimental groups when compared to the negative control group was not statistically significant.

4.Minimum quantities of solvent are expelled through the apical foramen during the removal of gutta-percha from the root canal. 

5.The amount of solvent that may become available to the tissues surrounding the tooth structure is several orders of magnitude below the permissible toxic dose.

Clinical significance:   


The controlled use of chloroform, halothane, or xylene at the  appropriate dose levels poses no health risk to the patient.