“Ferrule Comes First. Post Is Second!” Fake News and Alternative Facts? A Systematic Review.

Naumann M, Schmitter M, Frankenberger R, Krastl G.

J Endod. 2018 Feb;44(2):212-219.

Ferrule effect and maintaining cavity walls are the predominant factors with regard to tooth and restoration survival of endodontically treated teeth. Most studies do not confirm a positive effect of post placement.


Ultrasonic Irrigant Activation during Root Canal Treatment: A Systematic Review.

Căpută PE, Retsas A, Kuijk L, Chávez de Paz LE, Boutsioukis C.

J Endod. 2019 Jan;45(1):31-44.e13.

This review summarized and appraised published studies comparing ultrasonic irrigant activation and syringe irrigation, regarding the cleaning and disinfection of root canals and the healing of apical periodontitis.

The overall level of the available evidence was low, so no strong clinical recommendations could be formulated.

Ultrasonic activation is more effective in the removal of pulp tissue remnants based on both clinical and in vitro studies. It is also more effective in the removal of hard tissue debris in vitro. It remains unclear whether ultrasonic activation can reduce the microbial load further than syringe irrigation in vitro.

Intermittent ultrasonic irrigant activation did not improve the healing rate of apical periodontitis compared with syringe irrigation, after primary root canal treatment of teeth with a single root canal (based on a single medium-quality RCT).


Penetration of sodium hypochlorite into root canal dentine: effect of surfactants, gel form and passive ultrasonic irrigation.

Faria G, Viola KS, Coaguila-Llerena H, Oliveira LRA, Leonardo RT, Aranda-García AJ, Guerreiro-Tanomaru JM.

Int Endod J. 2019 Mar;52(3):385-392.

Aim To assess the penetration of sodium hypochlorite (NaOCl) gel or NaOCl solutions with surfactants, and the effect of passive ultrasonic irrigation (PUI) on penetration into dentinal tubules.

  1. In extracted bovine teeth NaOCl gel penetrated less into dentinal tubules than NaOCl solution.
  2. The addition of surfactants to NaOCl solutions did not increase penetration into dentinal tubules (Questionable).

[The NaOCl irrigants were titrated by the physicochemical spectrophotometry method to determine the chloride content available/ Results have not been reported; Production and expiry dates for regular solutions and modified ones (Chlor-Xtra) from the market also have not been reported. Which solutions have really been tested?]

  • The use of PUI increased NaOCl penetration into dentinal tubules.

[What do you think about the opportunity to compare the penetration depth into dentine tubules of one regular NaOCl solution passively delivered or ultrasonically activated? Penetrating into dentinal tubules and having there effective contact time, volume and renewal of the solution are very different things. I would not neglect the key role of surface tension in the penetration potential of irrigants]