Effectiveness of photon-initiated photoacoustic streaming in root canal models with different diameters or tapers

Cheng Wen; Yuanyuan Kong; Jian Zhao; Yang Li; Ya Shen; Xuechao Yang; Qianzhou Jiang

doi:10.1186/s12903-021-01671-4

Effectiveness of photon-initiated photoacoustic streaming in root canal models with different diameters or tapers

BMC Oral Health. 2021 Jun 15;21(1):307. doi: 10.1186/s12903-021-01671-4.

Authors

Cheng Wen¹, Yuanyuan Kong¹, Jian Zhao¹, Yang Li¹, Ya Shen², Xuechao Yang¹, Qianzhou Jiang³

Affiliations

¹ Department of Endodontics, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medical, Guangzhou, 510182, Guangdong, China.
² Division of Endodontics, Faculty of Dentistry, The University of British Columbia (UBC), 2199 Wesbrook Mall, Vancouver, V6T 1Z3, Canada.
³ Department of Endodontics, Affiliated Stomatology Hospital of Guangzhou Medical University, Guangzhou Key Laboratory of Basic and Applied Research of Oral Regenerative Medical, Guangzhou, 510182, Guangdong, China. jqianzhou@126.com.

Abstract

Background: This study aimed to compare the use of photon-initiated photoacoustic streaming (PIPS) and conventional needle irrigation (CNI) in conjunction with different concentrations of sodium hypochlorite (NaOCl) to remove Enterococcus faecalis (E. faecalis) suspended bacteria and biofilms from root canal systems with different diameters or tapers.

Methods: Artificial root canal samples (n = 480) were randomly divided into three groups (n = 160/group). The canals were prepared to fit file sizes #10/.02, #25/.02, or #25/.06. The size #10/.02 group was incubated for seven days. The size #25/.02 or #25/.06 group was incubated for 2 days. A stable biological model of E. faecalis infection was established. The root canals were washed with distilled water or with 1%, 2%, or 5.25% NaOCl combined with CNI or PIPS. Bacterial suspensions and biofilms were assessed using an ATP assay kit and fluorescence microscopy. Image-Pro Plus was used to analyse the average fluorescence intensity to determine the most suitable root canal irrigation solution.

Results: In the CNI and PIPS groups, the ATP value of the 5.25% NaOCl subgroup was the lowest, followed by that of the 2% and 1% NaOCl subgroups. The ATP value of the distilled water subgroup was the highest (P < 0.05). When the root canal taper was 0.02, the ATP value of the #10/.02 + PIPS group was significantly lower than that of the #25/.02 + CNI group (P < 0.05). The average fluorescence intensity of the #10/.02 + PIPS group was lower than that of the #25/.02 + CNI group (P < 0.05). When the apical diameter was #25, the ATP value of the 0.02 taper in the PIPS group was lower than that of the 0.06 taper in the CNI group (P < 0.05), and the average fluorescence intensity of the 0.02 taper + PIPS group was lower than that of the 0.06 taper + CNI group (P < 0.05). PIPS combined with 2% and 5.25% NaOCl effectively improved the long-term antibacterial effect after irrigation and re-culture for 6 h.

Conclusions: Compared with CNI, PIPS has greater ability to remove bacteria in root canals with a small preparation diameter and a small taper. PIPS with 2% and 5.25% NaOCl exhibited superior antibacterial and bacteriostatic effects.

Keywords: Diameter; PIPS; Root canal; Taper.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Dental Pulp Cavity*
Enterococcus faecalis
Humans
Photoacoustic Techniques*
Root Canal Irrigants / therapeutic use
Root Canal Preparation
Sodium Hypochlorite / therapeutic use

Substances

Root Canal Irrigants
Sodium Hypochlorite

Grants and funding

[2017]-210/Guangzhou Medical University