Ultrasonic agitation reduces the time of calcium hydroxide antimicrobial effect and enhances its penetrability

Abstract

Objectives: The objective of the present work was to evaluate the ultrasonic agitation, time and vehicle (propylene glycol or distilled water) on the antimicrobial potential and penetrability of calcium hydroxide pastes on infected dentin by means of Confocal Laser Scanning Microscopy (CLSM) and microbiological culture (MC). Materials and methods: Dentin specimens were infected with Enterococcus faecalis using a new contamination protocol of 5 days. The specimens were divided into eight groups and dressed with the pastes for 7 or 15 days: G1) calcium hydroxide (CH) + propylene glycol (prop)/7 days (d), G2) CH + prop/7d + ultrasonic agitation (U), G3) CH + distilled water (dw)/7d, G4) CH + dw/7d + U, G5) CH + prop/15d, G6) CH + prop/15d + U, G7) CH + dw/15d, G8) CH + dw/15d + U. The ultrasonic activation was made for 1 min in both directions with a plain point insert. After medications removal, the images obtained by CLSM showed the viable (green) and dead (red) bacteria with Live and Dead dye. By the MC, the dentinal wall debris obtained by burs were collected for colony counts. For the penetration test, the Rodamine B dye was added to the CH pastes and analyzed by CLSM. Results: The 7 and 15-days CH + prop+U pastes performed better antimicrobial efficacy, followed by the CH + dw+U/15d paste. Conclusions: All pastes demonstrated better penetration and antimicrobial activity against E. faecalis when agitated with ultrasound, even in periods of up to seven days. The propylene glycol vehicle showed better results. Clinical relevance: Agitation of the dressing that remains for less time inside the root canal can optimize the decontamination of endodontic treatment.

Evaluation of Solubility, and Volumetric and Morphological Alterations of Bioceramic Filling Material for Primary Teeth: A New Methodological Approach

“…Ultrasonic activation can be used to agitate the intracanal sealers and intracanal medication pastes. This enhances the intratubular dentin penetration of the sealer, thus promoting antimicrobial activity against Enterococcus faecalis [ 30 ] and minimizing the presence of gaps in vitro [ 31 ].…”

Effect of Ultrasonic Activation on Dentinal Tubule Penetration of Bio-C Temp and Ultracal XS: A Comparative CLSM Assessment

“…The vehicle of in which the medication is incorporated is another factor that can influence its penetration and diffusion into the dentinal tubules ( 2 , 3 , 28 ). The vehicle used by UltraCal XS is aqueous ( 11 ) while the one used by Bio-C Temp is viscous ( 16 , 33 ), reducing Bio-C Temp surface tension facilitating a greater penetration into the dentinal tubules ( 20 ). Particle size, vehicle and anatomy of the canals are all factors that must be considered when analyzing dentinal tubular penetration of a root canal medication ( 28 ).…”

“…The UA in a shaped canal, allows the ultrasonic tips to vibrate freely, transferring energy to irrigant solutions inside the canal ( 6 ). UA has also been used successfully to obtain a greater projection and tubular penetration of medicaments and sealers, increasing the antimicrobial action of CH ( 17 , 19 ) and reducing medication time between sessions ( 20 ), as well as preventing reinfection over time ( 21 – 24 ).…”