Irrigation effectiveness of continuous ultrasonic irrigation system: An ex vivo study

Evaluation of irrigant extrusion following the use of different root canal irrigation techniques: A systematic review and meta-analysis

This systematic review investigates whether different irrigation techniques have different effects on irrigant extrusion from mature tooth apices. Articles published between January 2000 and January 2022 were searched in six electronic databases (MEDLINE, Embase, Google Scholar, Web of Science, Scopus and Cochrane) using appropriate keywords. Overall, 2265 articles were screened by their titles and abstracts. Fifty-six full-text articles were selected based on the inclusion criteria. Of them, 17 in vitro studies were included in the systematic review and meta-analysis. The meta-analysis was conducted using the random-effects inverse variance method. The results showed that the negative pressure technique caused a lesser amount (p = 0.00) and frequency (p = 0.00) of extrusion than the open-ended needle irrigation. Sonic and ultrasonic activation caused less amount of extrusion than both open-ended (p = 0.00 or p = 0.01) and closed-ended needle (p = 0.00) irrigation.

Evaluation of the Antibacterial Efficacy of QMix and AgNP Solutions in Root Canals of Primary Molars: An In-Vitro Study

Purpose

The study aimed to evaluate QMix²ⁱⁿ¹ and silver nanoparticles (AgNPs) solution in eliminating Enterococcus faecalis (E. faecalis) bacteria within root canals of primary molars.

Materials and methods

The study sample consisted of 45 extracted primary molars, which were divided into three groups: Group 1 (control) NaOCl 5.25%, Group 2 (experimental) QMix^{2 in 1}, and Group 3 (experimental) AgNPs 4000 ppm. The root canals were sterilized within an autoclave and then contaminated with E. faecalis bacteria. The root canals were irrigated for five minutes in a quantity of 3 ml using a 31-gauge irrigation needle, and then bacterial smears were taken.

Results

Sodium hypochlorite, AgNPs, and QMix²ⁱⁿ¹ effectively reduced the bacterial count of Enterococcus within root canals of primary molars. There were statistical differences between all groups. QMix²ⁱⁿ¹ solution showed the greatest antibacterial efficacy, then NaOCl solution and AgNPs solution. 

Conclusion

All irrigation solutions used are effective in eliminating E. faecalis. QMix²ⁱⁿ¹ can be considered a good alternative to sodium hypochlorite in irrigation root canals of primary teeth.

Protocols for Mechanical Cleaning of the Post Space on the Bond Strength Between Root Dentin and Cementation System

OBJECTIVE

To evaluate the effects of mechanical versus chemical cleaning protocols for cleaning the root dentin surface before cementation of fiberglass posts for their effect on the bond strength, failure mode, and dentinal penetration of the cementing agent using an etch-and-rinse adhesive system on dentin prepared to receive a fiberglass post.

METHODS

Forty roots of bovine teeth were endodontically treated and prepared for fiber post cementation. The specimens were randomized into 4 groups of 10: Control group (CO) - irrigation with 2.5% NaOCl; DW group- irrigation with distilled water; RB group - rotating brush for cleaning root canals, and CUI group - continuous ultrasonic irrigation. The fiberglass posts were cemented, and the specimens were immersed in distilled water for 6 months. A push-out test was performed on the cervical, middle, and apical thirds of the samples. Dentinal penetration of the cementing agent and the fracture pattern were evaluated by laser confocal microscopy. Statistical analysis was performed using analysis of variance (ANOVA) and post hoc Tukey tests (α=0.05). Results: The RB and CUI groups showed significantly higher bond strength values when compared to the Control and DW groups (p<0.05). In addition, in the control and DW groups, the apical third presented lower bond strength values when compared to middle and cervical thirds.

CONCLUSION

While DW showed the highest incidence of adhesive type failure, CUI resulted in the highest dentinal penetration of the cementing agent (p<0.05). RB and CUI resulted in the highest bond strength between cementation system and root dentin. In addition, CUI favored greater dentinal penetration of fiberglass post cementing agent.