This new study did a great job and addressing some of the design problems with the previous study reviewed in our post titled, GentleWave by Sonendo: A First Look. While the previous study showed that the new GentleWave procedure could be considered a good alternative to conventional endodontic therapy, I felt that it failed support its claims of superiority over conventional endodontic treatment and specifically the claim to better remove the microbial load of the affected tooth.
The main issue with the study is that it again fails to have any positive or negative controls. It would have been easy to create a randomized, double-blinded study to compare the new GentleWave procedure with a conventional endodontic treatment. In stead, it simply evaluates the GentleWave technique and then goes to the literature to compare its success with conventional treatment.
The major improvements in this study are:
- Selection/Sampling Improvement: This study evaluated teeth with periapical lesions. These are the teeth that have bacterial issues and give us the most challenge in cleaning and obturation. This change in the study design, makes this study much more relevant and important.
- Attrition Improvement: This study lost only 1 of 45 patients in the study, while the previous study lost 16% to attrition.
- Standardization & Calibration of Examiners: training, calibration, independent scoring and consensus scoring of the periapical index (PAI) scores all demonstrate a desire for accuracy.
- Citation Bias: The comparisons made in the discussion to other studies, specifically Orstavik et. al. was more relevant because both studies were evaluating healing of patients with periapical lesions. Comparing two similar samples (teeth with periapical lesions using the PAI) makes for a more relevant discussion. The GentleWave success rate was listed at 97.7% at one year, while Orstavik's study reported 88% success rate at one year.
- Sponsorship Bias: While the study was still "funded in part" by Sonendo, the study design, proper selection/sampling, standardization of examiners all significantly improve the quality of the study design and do a better job at supporting the claims made by the manufacturer.
Overall, I think this new study is much more helpful and relevant. The next step is a larger, randomized, double-blinded clinical trial comparing GentleWave side by side with conventional treatment on teeth with periapical lesions.
Healing of Periapical Lesions after Endodontic Treatment with the GentleWave Procedure: A Prospective Multicenter Clinical Study Sigurdsson, Asgeir et al. Journal of Endodontics , Volume 44 , Issue 3 , 510 - 517