Title Insufficient Evidence to Determine if Ultrasonic Activated Irrigation During Root Canal Treatment Improves the Healing Rate of Apical Periodontitis
Clinical Question For patients with apical periodontitis undergoing root canal treatment, does ultrasonic activated irrigation lead to better healing rates than syringe irrigation alone?
Clinical Bottom Line There is currently insufficient evidence to determine whether ultrasonic activated irrigation (UAI) during root canal treatment improves the healing rate of apical periodontitis compared to syringe irrigation (SI). While most studies resulted in outcome or surrogate outcome improvement in the UAI groups, statistical significance was not achieved. Additional research with increased power and more homogenous study designs are required to determine whether UAI leads to better outcomes than SI alone.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
31399682Silva/20193 randomized clinical trials / 158 teethSystematic review of randomized trials
Key resultsIncluded studies compared the effect of UAI to non-activated SI on periapical healing and canal disinfection. Of the three RCTs selected for review, only one evaluated periapical healing rates while the other two studies evaluated disinfection rates as a surrogate outcome. Meta-analysis was not performed due to excessive heterogeneity in clinical procedure protocols and outcome assessments. Liang et al. evaluated periapical lesion healing rates (n = 84, UAI healing = 95.1%, SI healing = 88.4%, p >0.05). Herrera et al. evaluated the effect of UAI on reduction of colony forming units (CFUs) of obligate and facultative anaerobic bacteria and found no statistical difference compared to SI (p >0.05). Nakamura et al. used quantitative polymerase chain reaction (qPCR) to measure bacterial counts and found that UAI did significantly reduce bacteria counts compared to SI (p <0.05).
30264624Moreira/20195 randomized clinical trials / 152 patientsMeta-Analysis
Key resultsThe objective of this systematic review with meta-analysis was to determine whether UAI leads to improved disinfection of the root canal system as compared to SI. While not directly evaluating apical periodontitis healing as an outcome, canal disinfection was evaluated as a surrogate outcome. Four of the five studies reviewed were microbiological assessments (three measured CFUs; one measured PCR) and one was a histological assessment. The three studies that measured disinfection rates with CFUs were included in the meta-analysis. While there was a greater reduction of bacteria in the UAI group than the SI group, the difference was not statistically significant (OR = .34, CI 95%: 0.10–1.19; p = .1623). Of the other two studies not included in the meta-analysis, one reported no significant reduction (PCR evaluation) and the other that there was a significant reduction in bacteria (histological evaluation).
Evidence Search (("ultrasonics"[MeSH Terms] OR "ultrasonics"[All Fields] OR "ultrasonic"[All Fields]) OR passive[All Fields]) AND ("wound healing"[MeSH Terms] OR ("wound"[All Fields] AND "healing"[All Fields]) OR "wound healing"[All Fields] OR "healing"[All Fields]) AND ("therapeutic irrigation"[MeSH Terms] OR ("therapeutic"[All Fields] AND "irrigation"[All Fields]) OR "therapeutic irrigation"[All Fields] OR "irrigation"[All Fields]) AND ((("dental pulp cavity"[MeSH Terms] OR ("dental"[All Fields] AND "pulp"[All Fields] AND "cavity"[All Fields]) OR "dental pulp cavity"[All Fields] OR ("root"[All Fields] AND "canal"[All Fields]) OR "root canal"[All Fields]) AND ("therapy"[Subheading] OR "therapy"[All Fields] OR "treatment"[All Fields] OR "therapeutics"[MeSH Terms] OR "therapeutics"[All Fields])) OR endodontic[All Fields])
Comments on
The Evidence
Validity: Both systematic reviews used the Cochrane Handbook to assess the quality of the included studies, which evaluated the following factors: random sequence generation, allocation concealment, blinding of participants and personnel, blinding of outcome assessment, incomplete outcome data, selective reporting, and either eligibility criteria (Moreira et al.) or other sources of bias (Silva et al.). Silva et al. classified all three studies included in their systematic review as having a low risk of bias. While none of the included studies could mask participants due to different equipment needed for the two different treatment protocols, two studies did mask the evaluators during outcome assessment. The authors performed a power analysis that found insufficient power in two studies. Additionally, all three studies only analyzed teeth with a single canal per root which limited canal complexity in which greater result variance may have been manifested between the different irrigation techniques. Furthermore, bacteria samples were only taken from the main canal which excluded bacteria that may have been present in dentinal tubules, accessory canals or other alcoves, thereby potentially overstating the percentage of disinfected teeth. The results of the quality assessment performed by Moreira et al. were mixed and the authors determined that “there is still poor evidence on this subject.” Other weaknesses of the studies reviewed by Moreira et al. include different NaOCl concentrations between studies and that the bacterial culturing methods could potentially underreport the presence of bacteria. Perspective: Due to the low number of total studies included in the two systematic reviews (eight), the low power of most of the studies and the procedural protocol heterogeneity between the studies, it is difficult to definitively determine whether UAI leads to superior outcomes (either in healing rate or bacterial reduction) compared to SI during root canal treatment. However, although statistical significance was only achieved in two of the studies, all studies did show either a higher healing rate or bacterial reduction. Given the minimal additional time and expense required by UAI, these results suggest that the time and money may be well spent.
Applicability For providers wanting to introduce ultrasonic into their practice, there is an initial expense to acquire a unit and tips. However, given the other applications of ultrasonic in dentistry, many providers already possess a unit, and once it is purchased, the incremental expense and time of UAI per patient is slight. Additional research on this topic is required to determine if the time and expense are validated.
Specialty (Endodontics) (General Dentistry)
Keywords ultrasonic activation, irrigation, root canal treatment, healing
ID# 3416
Date of submission 11/27/2019
E-mail sheppardl@livemail.uthscsa.edu
Author Lucas Sheppard, DMD
Co-author(s) John Lovell, DDS
Co-author(s) e-mail lovellj@livemail.uthscsa.edu
Faculty mentor Asma A. Khan, BDS, PhD
Faculty mentor e-mail khana2@uthscsa.edu
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
Comments and Evidence-Based Updates on the CAT
None available