Endodontic ‘solutions’ part 2: an audit comparing current practice in belfast with uk and republic of ireland dental schools

There are two types of endodontic case, those involving teeth that have never been root-treated, known as primary, and those where a previous root treatment has failed, known as secondary. All cases involve microbes which are organized into protective adhesive biofilms,1 but the species of microbes differ in primary and secondary cases. Primary infections tend to include many species, involving mostly gram negative anaerobes plus fungi.2 Secondary infections, however, involve fewer species and often include E faecalis,3–5 which can be difficult to eliminate.6

The aim of endodontic treatment or retreatment is to reduce the infection of the root canal system (RCS) sufficiently to allow the host response to favour healing of the periapical tissues.

Following the literature review in Part 1 of this paper it is clear that there are many endodontic ‘solutions’ available which are claimed to help prepare and disinfect the RCS. There are, however, only a few that have evidence to support their use clinically, although no detailed guidelines exist on this topic from the British Endodontic Society (BES), the European Society of Endodontology (ESE) and the American Endodontic Society (AES). In the absence of such guidelines, and in order to formulate protocols for primary and secondary cases for use in Belfast Dental School, an audit was undertaken on the current use of endodontic ‘solutions’ across UK and Republic of Ireland dental schools.

The current practice in the Restorative Department, Belfast Dental School is as follows: routinely no pre-op oral rinse is given: having accessed the RCS canal lubricant 19% ethylenediaminetetraacetic acid (EDTA) paste (File-Eze®, Ultradent Products Inc, South Jordan, UT, USA) is used with files: 10–20 ml/canal of 0.5% sodium hypochlorite (NaOCl) at room temperature, is the only irrigant used for both primary and secondary infections. In multi-visit cases, calcium hydroxide (Ca(OH)₂) paste (Hypo-cal, Ellman Int'l Inc Oceanside, New York, USA) is the main intracanal medicament used for both primary and secondary infections; along with the occasional use of Ledermix paste (Blackwell Supplies, Henry Schein UK Holdings Ltd, Kent, UK) if hyperaemia or failed anaesthesia occurred.

Results

The response rate was 87.5%, with 14 of the 16 dental schools participating (including Belfast). The percentage of dental schools using the various ‘solution’ categories outlined is presented in Table 1.

Table 1. The percentage of dental schools using various endodontic ‘solutions’.

Endodontic Solution	% Dental Schools
Pre-op oral rinse	21
Canal lubricant(s)	100
Sodium hypochlorite	100
Other irrigant(s): Primary cases Secondary cases	8686
Intracanal medicament(s): Primary cases Secondary cases	93100

All dental schools used sodium hypochlorite (NaOCl) but with a wide range of volume (1–40 ml/canal) and range of strength (Figure 1) and only one institution warmed the solution. Only one responder mentioned a volume less than 10 ml/canal.

Primary cases

The other irrigants reportedly used included sterile water (H₂0), 0.2–2% chlorhexidine gluconate (CHX), 17% EDTA solution and 10% citric acid (CA) (Figure 2). The intracanal medicament used in most primary cases was non-setting Ca(OH)₂ paste (Figure 3).

There were 10 different protocols from the 14 dental schools for irrigant sequencing in primary cases:

NaOCl;

NaOCl; distilled H₂O;

NaOCl; sterile H₂O; CHX occasionally; EDTA final flush;

CHX & NaOCl (repeating); final flush NaOCl;

NaOCl & CA (repeating); final flush NaOCl;

EDTA; NaOCl; CHX;

NaOCl; CHX; final flush EDTA;

EDTA & NaOCl (repeating);

NaOCl & EDTA (repeating); final flush EDTA;

NaOCl (20 min); EDTA (3 min).

Secondary cases

The ‘other irrigants’ used for secondary infections in some of the dental schools were the same as those for primary infections, apart from the inclusion of iodine (I) preparations (Figure 4). The intracanal medicaments used in retreatment cases included non-setting Ca(OH)₂ paste, 2% CHX gel, 10% povidone-iodine (I) or Ca(OH)₂ and I combined (Figure 5).

Of responders, 57% had the same irrigant sequence for primary and retreatment cases. There were 13 different protocols from the 14 dental schools for irrigant sequencing in secondary cases:

NaOCl;

NaOCl; CHX;

NaOCl; sterile H₂O; occasionally CHX; EDTA final flush;

NaOCl; distilled H₂O;

CHX & NaOCl (repeating); final flush NaOCl;

NaOCl & CA (repeating); penultimate rinse IKI (5–10 min); final flush NaOCl;

EDTA; NaOCl; CHX;

NaOCl; CHX or Povidone-Iodine;

NaOCl; CHX; EDTA;

EDTA & NaOCl (repeating);

NaOCl; Povidone-Iodine; CHX; EDTA;

NaOCl & EDTA (repeating); occasional Povidone-Iodine; final flush EDTA;

NaOCl (20 min); EDTA (3 min); NaOCl (20 min); EDTA flush; CHX (3 min). Reported comments included: use of 4% CHX (Hibiscrub Antiseptic Cleansing Solution, Regent Medical, Bedfordshire, UK) as an initial canal lubricant; use of freshly mixed Ca(OH)₂ : Ca(OH)₂ was left in situ for 2–3 weeks; use of Ledermix paste (Lederle Pharmaceutical, Wolfrathausen, Germany) when hyperaemic vital tissue found within the RCS; use of Metapex^TM (Meta Biomed Co Ltd, Chungbuk, Korea) (contains Ca(OH)₂ and iodoform) if symptoms were present; use of Sterilox® Solution (Ultradent Products, Inc, South Jordan), (super-oxidized water) and use of Bio Pure^TM MTAD^TM Cleanser (Dentsply International, York, PA, USA), a doxycycline, citric acid and detergent mix, which was reportedly used occasionally by one school.