nitinol and Periapical-Periodontitis

Prevention or treatment of apical periodontitis is aimed at disinfecting the root canal system so that the periradicular tissues are not vulnerable to attack from microbiota within the tooth. This is achieved by a process of cleaning and shaping the root canal space. The fundamental principles underlying this process have not changed in decades. In contrast, the armamentarium available to the clinician continues to evolve rapidly. The use of specially designed nickel titanium (NiTi) files to create a glidepath allows the clinician to manage tight curved canals more predictably in situations which would otherwise have proved too difficult using conventional techniques. Other files, designed to shape the canal, have been developed using metallurgic principles which permit NiTi files to be more flexible and resistant to cyclic fatigue. These newer systems also require fewer instruments to prepare a canal and some, which have adopted a reciprocating (rotational) motion, may only require one file. Progress is also being made in enhancing efficacy of irrigant activity using negative apical pressure systems, sonic and ultrasonic agitation techniques. These contemporary techniques used to clean and shape the root canal system should result in improved confidence and predictability when managing endodontic disease.

Topics: Alloys; Equipment Design; Humans; Periapical Periodontitis; Radiography, Dental; Root Canal Obturation; Root Canal Preparation; Root Canal Therapy

The effect of irrigation time on the antimicrobial efficacy of an apical negative pressure irrigation system was examined in vitro, followed by validation of the antimicrobial effect in vivo using the identified optimal irrigation time.. For the in vitro experiment, 44 extracted premolars were decoronated, instrumented, autoclaved and inoculated with Enterococcus faecalis (ATCC 29212) for 21 days. Four teeth were used as positive control, without irrigation. Each of the remaining 40 teeth was irrigated with 2.5% NaOCl, delivered via the EndoVac MacroCannula for 10 s, and subsequently via the EndoVac MicroCannula for 15, 30, 45, 60 or 90 s per canal, respectively (N = 8). After irrigation, microbial samples were collected, transferred to BHI broth and incubated for counting of bacterial colony forming units (CFUs). Based on the in vitro results, 8.25% NaOCl was delivered via the EndoVac MicroCannula for 60 s, during root canal treatment of 20 human subjects presented with apical periodontitis. Microbial samples retrieved in vivo prior to canal instrumentation (S0), after chemomechanical debridement (S1) and after irrigation with EndoVac (S2) were cultured in an anaerobic chamber for 7 days for CFU evaluation.. Compared with the control, irrigation significantly reduced bacterial populations (p < .05). Irrigation delivery via the EndoVac demonstrated improved antibacterial efficacy with increased irrigation time (p < .05). Samples retrieved from canals after NaOCl delivery in vivo with the EndoVac for 60 s were all culture-negative.. Microbial elimination may be achieved with 8.25% NaOCl delivered via the EndoVac apical negative pressure irrigation device for 60 s.. With the use of the EndoVac apical negative pressure irrigant delivery system, optimal elimination of the intracanal bacterial load can only be achieved when sodium hypochlorite is delivered via the MicroCannula for at least 60 s per canal.

Topics: Alloys; Anti-Infective Agents; Bacterial Load; Bicuspid; Debridement; Dental Pulp Cavity; Disinfection; Enterococcus faecalis; Humans; Periapical Periodontitis; Pressure; Root Canal Irrigants; Root Canal Preparation; Root Canal Therapy; Sodium Hypochlorite; Thiosulfates; Time Factors