Thermal Analyses of Six Gutta-Percha Based Obturation Points

Objective: Various new technologies and concepts of incorporating resin, glass ionomer and bioceramic (BC) particles/coatings into gutta-percha (GP) points have emerged. There is a scarce amount of information available on whether these processes affect the thermal properties of the obturation point.  The purpose of this study was to compare the melting point and latent heat of melting for several gutta-percha based points using differential scanning calorimetry (DSC).

Method: Commercially available gutta-percha based points [Lexicon^TM (pink and green)] from Dentsply Tulsa Dental, ActivGP^TM, BC Gutta-Percha^TM, Endosequence^TM Gutta-Percha from Brasseler USA, and EndoRez^TM from Ultradent Products (n=5/brand) were analyzed using DSC (20°C →200°C →0°C at 10°C/min).  Thermograms were qualitatively compared and thermal melting parameters (temperature and enthalpy change) were compared via ANOVA/Tukey (a=.05). 

Result:

Results are shown in the table below.

Point	Main Melting Peak (oC)	Melting Enthalpy DH (J/g)
Lexicon-Pink	49.4 C	10.2 AB
Lexicon-Green	50.4 B	9.5 B
Activ GP	51.1 AB	11.0 A
BC GP	49.1 C	10.7 A
Endosequence GP	51.7 A	10.6 A
EndoRez	47.5 D	9.7 B

Different letters for each parameter denote significant (p<0.05) differences between groups.  Qualitatively, subtle differences appeared in the thermograms of the respective points.

Conclusion: Significantly different melting parameters were noted among the gutta-percha based points. However, the magnitude of the differences is most likely not clinically significant, indicating the various manufacturing processes do not appreciably change the thermal properties of the gutta-percha points.