Authors: Wong M, Peters DD, Lorton L.
Title: Comparison of gutta-percha filling techniques, compaction (mechanical), vertical (warm), and lateral condensation techniques, Part 1.
Journal: J Endod
Date: Dec 1981
Citation: 7(12):551-8
Category: Obturation
Evidence-based Ranking: 5
Purpose/Objectives: To present a method of fabricating an artificial canal and to compare the replication abilities, volumetric changes, and simulated procedure times of three gutta-percha (GP) filling techniques (listed in the title).

Materials & Methods: Fabrication of the standardized root canal filling – an extracted maxillary lateral incisor was c/s to a size 60. Through the use of resin and gold casting, a cast-gold root canal space was created. This gold-canal space was filled using the different filling techniques 16 times each. Each filling was timed. The volume was studied and the canal replication was evaluated by 3 evaluators.

Results: Weight and volume changes – The average initial weight in air was 77.24 mg lateral, 80.00 mg vertical, and 90.65 mg mechanical. The weight changes in air after 2 weeks were not significant. The volume changes for lateral was greater than the weight in air change by 1.13% increase. The vertical volume lessened 0.45%, and the mechanical lessened 0.62%. The average time of procedure was 7.99 minutes for vertical, 5.62 for lateral, and 1.31 for compaction. Replication abilities – The vertical technique was judged significantly better than lateral or mechanical in its ability to replicate the test canal. Lateral was consistently judged poor or barely acceptable by all investigators.

Author’s Conclusion: The artificial root canal allowed to standardize the fills, time the fills, avoid solvents used in vivo, and enabled immediate observation and measurements. The weight and volume changes – higher average weight of vertical compared to lateral indicates more GP is introduced into the canal system. The vertical technique best replicates the canal system. The time for the compaction technique is much faster than lateral or vertical techniques. The results for vertical condensation were superior to lateral and its clinical use is recommended. Although the volumetric differences were not statistically significant, the vertical technique did place a larger mass of GP into the root canal space compared to lateral.

Validity of Conclusion: The results seem valid.

Reviewer’s Comments: The study provides a useful mechanism to compare obturation techniques. Further, it seems logical that using a warm technique like the compaction or vertical technique best adapts the GP. There was no mention of whether or not the study was blinded, and some bias may exist between the evaluators. Even with some bias, I find the results to be relevant.