Three-dimensional obturation of the root canal using injection-molded, thermoplasticized dental gutta-percha

By Yee FS, Marlin J, Krakow AA, Gron P.

Date: 05/1978
Journal: JOE


•Purpose:  to study the feasibility of root canal obturation by using thermoplasticized, injectable gutta-percha. 

•n= divided in to 2 samples based on the evaluation method;

•1st sample:

n: 20 single- rooted and four double-rooted teeth filled with thermoplasticized GP without sealer; evaluated by radiographic and visual inspection

•2nd sample:

n: 40 single rooted teeth divided in to 4 gps: Gp.1: lateral condensation with AH26 sealer, Gp.2; vertical condensation with kerr sealer, Gp.3: injection of thermoplasticized GP without sealer, Gp.4: injection of thermoplasticized GP with AH26 sealer; evaluated by dye penetration


oExperimental tech: 2 pre-op RG, MD &BL. Access, root canal system was cleaned and shaped. The largest syringe selected so that it could negotiate the canal to within 4 mm of the root apex

o 18- gauge syringe needle was used as GP carrier heated to 160 C in a glycerin bath.

oTeeth were then obturated with the thermoplasticized GP and evaluated for adaptability, reproduction of the irregular RC surfaces, and tooth/filling interface.

Highlighted Results: 

oRadiographic results showed uniform density of thermoplasticized fillings, with the occasional exception of small voids. No voids detected when sealer was used. The technique also permitted obturation of accessory and lateral canals.

oThermoplasticized GP maintained enough plasticity for condensation for 2 minutes after heating; void elimination was possible less than 1 m after heating.

oThe extent to which dye had visibly penetrated the tooth-filling interface (leakage) was essentially similar among the specimens of the four treatment groups.

oMethylene blue was typically limited to the region surrounding the apical terminus. Some dye penetration was observed within the middle third of the root in two specimens obturated with injected thermoplasticized GP without sealer. No instance of dye penetration when sealer was used.

oClinical significance:

oInjected thermoplasticized GP could produce an effective apical seal, especially when used in conjunction with sealer.