Influence of ultrasonic agitation of the sealer on the intratubular antimicrobial activity and on the filling quality of isthmuses in mesial roots of mandibular molars

Author(s)

Murilo Priori Alcalde

• Document type: Master's Dissertation
• Press: Bauru.
• Institution: Universidade de São Paulo (USP). Faculdade de Odontologia de Bauru (FOB/SDB)
• Defense date: 2015-06-12

Examining board members

Clovis Monteiro Bramante; Ricardo Affonso Bernardes; Rodrigo Ricci Vivan

• Advisor: Clovis Monteiro Bramante

Abstract

In this study it was assessed the presence voids, gaps in the sealer/dentin interface, the intratubular sealer penetration in canals and isthmuses and intratubular antimicrobial effect of the AH Plus sealer when ultrasonic activation was performed during obturation. 30 mesial roots of mandibular first molars were selected and divided into 2 groups (n=15). Root canal instrumentation was performed with the reciprocating system Reciproc (R25) and finished with the Mtwo (35.04) rotary instrument. Then the AH Plus sealer was mixed with Rhodamine B and was inserted into the root canals with a Lentulo spiral #35. In group 1 the ultrasonic activation of the sealer was performed while in group 2 was not activated. Then, the root canal filling was performed using the single cone technique. After 7 days of storage the roots were sectioned at 2, 4 and 6 mm from the apex and analyzed in the stereomicroscope and by confocal laser scanner microscopy. To the antimicrobial test 30 bovine incisors cut into cylinders with 6 mm in thickness were used. The root canals diameter was standardized with a K file # 80 and then contaminated with Enterococcus faecalis (ATCC 29212) for 4 days. After this period the samples were divided into 3 groups (n = 30). In group 1 the ultrasonic activation of the sealer was perfomed and filled with single cone technique; in group 2 the sealer was not ultrasonic activated and in group 3 the canals were not obturated (control group). The roots were sectioned in the buccal-palatal direction and stained with LIVE / DEAD stain to assess the bacterial viability by confocal laser microscopy. For analysis of ultrasonic activation of the sealer on the filling quality of the canals and isthmuses, a non-parametric Mann-Whitney test (p <0.05) was used. For the analysis of the intradentin antimicrobial action, a Kruskal-Waliis nonparametric and Dunn\'s test was used (p <0.05). The results showed that the ultrasonic agitation of the AH Plus sealer favored the isthmus filling and the intratubular penetration. Also, the ultrasonic activation of AH Plus sealer reduced bacterial viability. It was concluded that the ultrasonic agitation of the sealer favored higher intratubular penetration, lower presence of gaps and voids and higher antimicrobial activity. (AU)

• FAPESP's process: 13/08296-6 - Influence of ultrasonic agitation of sealer on antimicrobial intra-dentin and isthmus filling in mandibular mesial root canals molars.
• Grantee: Murilo Priori Alcalde
• Support Opportunities: Scholarships in Brazil - Master