Dental Tribune United Kingdom Edition

April 9-15, 2012United Kingdom EditionDENTINE CARE INNOVATION ... is the rst all-in-one, biocompatible and bioactive material to use wherever dentine is damaged BiodentineTM Pulpotomy BiodentineTM Dentine caries BiodentineTM Perforation BiodentineTM Immature root BiodentineTM Pulp exposure BiodentineTM Resorptions BiodentineTM Apical surgery BiodentineTM For crown and root indications Helps the remineralisation of dentine Preserves pulp vitality and promotes pulp healing Replaces natural dentine with the same mechanical properties C M Y CM MY CY CMY K Biodentine Probe.pdf 1 23/05/2011 10:04:42 A im: To investigate the ef- fects of power setting, type of irrigant and duration of ultrasonic irrigant agitation with IrrisafeTM on the mean percent- age change in the cross-section- al area and diameter of artificial root canals in an in-vitro model. Methodology: Twenty-five extracted anterior human teeth were collected and split into twohalves, each of which was embedded in epoxy resin. The external root surfaces were pol- ished to produce flat, smooth dentine surfaces. A pilot score was used as a guide to prepare an artificial canal using rotary instruments to a size 30/.06. The root canals were randomly assigned to five groups. Group 1: irrigation with 2.5 per cent NaOCl, ultrasonic agitation at power setting 7 (n=5); Group 2: irrigation with 17 per cent EDTA, ultrasonic agitation at power set- ting 7 (n=5). Groups 3, 4, and 5 were irrigated with 2.5 per cent NaOCl, 17 per cent EDTA, 2.5 per cent NaOCl, with ultrasonic agi- tation at power setting 4 (n=5), 7 (n=5) and 10 (n=5) respectively. Irrigant was delivered with a sy- ringe and ultrasonically agitated with a P5 Satelec® and IrrisafeTM tips. Canal area and depth were measured at 17, 16 and 9mm from the canal orifice at baseline and after one, two and five min- utes of ultrasonic agitation. This study came about as a result of a presentation that Chris Stock, Godfrey Cutts and I made to Prof Kish Gulabivala. We showed him a protocol for shaping and then cleaning root canals using Irrisafe. He an- nounced that all steel instru- ments and tips remove dentine and cut root canals, so I set out to prove him wrong! I would like to express my thanks to Prof Gulabivala for the idea behind this project and the incredible opportunity he af- forded me. Contemporary endodontics falls into three distinct catego- ries: 1Preparation (mechanical shaping) 2Irrigation (syringe flushing and adjunctive cleaning) 3Obturation (sealing the root canals in three dimensions) The existence of several mor- phologically different micro-or- ganisms was shown to be associ- ated with necrotic pulps as early as 1984 by W.D. Millar. Bacteria in the root canal system has been shown to cause apical periodon- titis in gnotobiotic rats (Kake- hashi et al. 1965). Sundqvist demonstrated that 18 out of 19 traumatised but intact teeth as- sociated with periapical radio- lucencies gave positive bacterial cultures (Sundqvist 1975). Schilder (1967) suggested that the root canal be cleaned and then shaped to allow for three-dimensional obturation. However, at least 38 per cent of the root canal surface could re- main uninstrumented during root canal treatment (Peters et al. 2001) and 70 per cent more debris remained following in- strumentation when compared with instrumentation and irriga- tion (Baker et al. 1975) Furthermore the landmark studies of Byström and Sundqvist (1981, 1983) demonstrated a 100-1000 fold decrease in bac- terial counts when 0.5 per cent Soduim Hypochlorite (NaOCl) was introduced instead of sa- line. Therefore it has generally been accepted that a chemo-me- chanical approach to root canal debridement is required to sig- nificantly reduce the bacterial load that may encourage more James Prichard discusses the effect of ultra- sonic irrigation variables on the dimensions of artificial root canals An in-vitro study Fig 1 Fig 2 Fig 3