A laboratory study of root canal and isthmus disinfection in extracted teeth using various activation methods with a mixture of sodium hypochlorite and etidronic acid

Abstract

AimTo evaluate in a laboratory setting the antibiofilm activity of several irrigating protocols including conventional irrigation, ultrasonic activation and XP‐endo Finisher, with a mixture of sodium hypochlorite and etidronic acid in infected isthmuses and root canals of extracted human mandibular molar teeth.MethodologyFifty‐six mesial roots of mandibular molars, half of them with a continuous isthmus from the cervical to the apical third between the two root canals (type 1), and the other half with a continuous isthmus from the cervical to the middle third and one canal in the apical third (type 2), were included. The root canals were contaminated for 7 days with an Enterococcus faecalis suspension. There were three experimental groups plus a control group (n = 7 per type of root canal anatomy). All the root canals, except for the control group that was not treated, were chemomechanically prepared and then assigned to one of the experimental groups according to the final adjunctive procedure: conventional irrigation, ultrasonic activation or XP‐endo Finisher activation. The irrigating solution used was a combination of 2.5% sodium hypochlorite and 9% etidronic acid, and the final protocols were applied for three cycles of 30 s with a 3 mL volume. The antibiofilm activity was evaluated at each location (root canal and isthmus) and third (cervical, middle and apical) using confocal laser scanning microscopy and the live/dead technique. Statistical analysis was performed using SPSS (descriptive statistics) and SUDAAN (P‐value calculations).ResultsRoot canals had significantly lower biovolume values than the isthmuses (P < 0.05). The biovolume in the root canals was significantly reduced in all the experimental groups in all the thirds except for conventional irrigation in the apical third (P > 0.05). In the cervical and middle thirds, ultrasonic activation was associated with the lowest biovolumes (P < 0.05), followed by XP‐endo Finisher. In the isthmus, disinfection was similar in all the thirds for all the protocols. Conventional irrigation was associated with intermediate values with no significant differences from the control group or from the activated protocols (P > 0.05), although the latter were significantly different from the control group (P < 0.05). No differences were found between ultrasonic activation and XP‐endo Finisher in the middle and apical thirds (P > 0.05) in the isthmuses.ConclusionsIn this laboratory study on extracted teeth, the isthmus was more difficult to disinfect than root canals. In the root canals, ultrasonic activation and XP‐endo Finisher had a greater effectiveness than conventional irrigation. In the isthmuses, no differences were observed between the two activation techniques and conventional irrigation.

Instrumentação com XP- Finisher como potencializador da desinfecção do sistema de canais radiculares – revisão integrativa

“…Na maioria dos encontrados quando comparada ao XPF, este último obteve melhores resultados, tanto na remoção de smear layer e detritos, como também na eliminação das bactérias do biofilme do canal radicular. O estudo de Azim et al (2016), assim como o de Villalta-Briones et al (2020), utilizaram a microscopia confocal de varredura a laser (CLSM) como método de análise. No primeiro estudo, a CLSM foi utilizada para observar a redução de bactérias nos túbulos dentinários.…”

“…No canal principal também foi usado o teste MTT, que é um ensaio calorimétrico para avaliar as células metabolicamente ativas. Já no estudo de Villalta-Briones et al (2020), a redução do biofilme foi verificada pelo CLSM, nos 3 terços do canal de molares com raízes que apresentassem istmo tipo V, ou seja, quando há comunicação completa entre dois canais. Em ambos os estudos o XPF apresentou melhor desempenho no canal principal que a IC, até mesmo em 50µm de extensão nos túbulos dentinários (Azim et al, 2016).…”

A critical analysis of research methods and experimental models to study irrigants and irrigation systems

“…It should be noted that wax, nail polish and silicone putty may not be enough to create a fluid‐ and air‐tight apical seal (Tay et al, 2010). In addition, creating an apically closed system is more difficult when the roots are split/sectioned and reassembled (Bhuva et al, 2010; Villalta‐Briones et al, 2021). The clinical relevance of laboratory models that do not ensure an apically closed root canal system during irrigation is very limited (Parente et al, 2010; Tay et al, 2010).…”

“…Thus, it is important to include root canals with similar anatomy. Pre-instrumentation is usually required to facilitate the entrance of bacteria in the root canal following the immersion in the bacterial suspension (Gazzaneo et al, 2019) or inoculation (Villalta-Briones et al, 2021). Either way, successful biofilm formation on the root canal wall should be confirmed (Bhuva et al, 2010).…”

Efficacy of Handpiece Mounted Continuous Irrigation System for the Removal of Residual Pulpal Debris During Root Canal Preparation

“…A crucial factor influencing the successful outcome of a nonsurgical endodontic treatment is the implementation of a thorough chemomechanical debridement and disinfection of the root canal system, especially of the apical third region. 1,2 The apical region consists of wide anatomic variation and acts as a reservoir of microbes and dentino-pulpal debris (DPD) formed during root canal preparation. The DPD may jeopardize the seal created by the obturating materials.…”