Bacteria have been implicated in the pathogenesis and progression of pulp and periapical diseases. The primary aim of endodontic treatment is to remove as many bacteria as possible from the root canal system and then to create an environment in which any remaining organisms cannot survive. This can only be achieved through the use of a combination of aseptic treatment techniques, chemomechanical preparation of the root canal, antimicrobial irrigating solutions and intracanal medicaments. The choice of which intracanal medicament to use is dependent on having an accurate diagnosis of the condition being treated, as well as a thorough knowledge of the type of organisms likely to be involved and their mechanisms of growth and survival. Since the disease is likely to have been caused by the presence of bacteria within the root canal, the use of an antimicrobial agent is essential. Many medicaments have been used in an attempt to achieve the above aims but no single preparation has been found to be completely predictable or effective. Commonly used medicaments include calcium hydroxide, antibiotics, non-phenolic biocides, phenolic biocides and iodine compounds. Each has advantages and disadvantages, and further research is required to determine which is best suited for root canal infections.Key words: Endodontics, bacteria, antimicrobial, medicaments.Abbreviations and acronyms: Ca(OH) 2 = calcium hydroxide; CFU = colony forming units; CHX = chlorhexidine; CMP = camphorated monochlorophenol; CP = camphorated phenol; IPI = iodine potassium iodide; LPS = lipopolysaccharide; NaOCI = sodium hypochlorite; PEG = polyethyleneglycol; PMCP = paramonochlorophenol; QAC = quaternary ammonium compounds.

The aim of this investigation was to quantify the discolouration of tooth roots caused by various medicaments and sealers. The roots of extracted teeth were chemo-mechanically prepared and the smear layer removed. The roots were filled with either Multi-Cal (Pulpdent Corporation, Watertown, MA, USA), Ledermix (Lederle Laboratories, Wolfratshausen, Germany), 2% chlorhexadine acetate in polyethylene glycol (PEG), 5% clindamycin in PEG, PEG alone (as a vehicle control), sealers AH26 (De Trey Dentsply, Zurich, Switzerland), AH Plus (De Trey Dentsply), an experimental epoxy resin with zirconium dioxide (Millenium Chemicals, Rockingham, Western Australia) or Araldite (Selleys Pty Ltd, Sydney, Australia). The roots were maintained at 37°C in dark humid conditions and standardised images of the coronal surfaces recorded over 12 months. Ledermix caused the most darkening of the introduced medicaments, while calcium hydroxide and the materials in PEG did not cause darkening. AH26 caused more darkening than did the other sealers. It was concluded that the use of alternatives to Ledermix and AH26 should be considered when aesthetics are important.

Background:  The aim of this study was to determine the in vitro antimicrobial activities of various endodontic medicaments and their bases against selected organisms using an agar diffusion assay.Methods:  An agar well diffusion assay was used to test the antimicrobial action of some commonly used endodontic medicaments (Ledermix paste, Pulpdent paste, Ultracal paste, and a 50:50 mix of Ledermix and Pulpdent pastes) and their bases. Three bacterial species (E. faecalis, P. micros, P. intermedia) and one yeast (C. albicans) were selected. The diameters of growth inhibition zones and pH were assessed.Results:  P. micros demonstrated the highest level of in vitro resistance. Pulpdent and Ultracal pastes had the highest pH (12.64 and 12.53, respectively). The addition of Pulpdent to Ledermix did not increase the zone sizes significantly.Conclusions:  All the commercial products showed some in vitro antimicrobial activity. Ledermix paste and the 50:50 Ledermix/Pulpdent mixture being the most effective in this model. The known anti‐inflammatory/analgesic properties of Ledermix and the results from this agar model suggest that the 50:50 Ledermix/Pulpdent combination would be the preferred medicament for clinical use in symptomatic cases, even though the addition of calcium hydroxide to Ledermix did not appear to be synergistic in terms of enhancing the antimicrobial action.

Calcium hydroxide pastes have been used in endodontics since 1947. Most current calcium hydroxide endodontic pastes use water as the vehicle, which limits the dissolution of calcium hydroxide that can be achieved and, thereby, the maximum pH that can be achieved within the root canal system. Using polyethylene glycol as a solvent, rather than water, can achieve an increase in hydroxyl ions release compared to water or saline. By adopting non-aqueous solvents such as the polyethylene glycols (PEG), greater dissolution and faster hydroxyl ion release can be achieved, leading to enhanced antimicrobial actions, and other improvements in performance and biocompatibility.

Formaldehyde is present in most living cells and the environment. In dentistry, patients may be exposed to formaldehyde through the use of several endodontic materials (e.g. AH 26) and during formocresol pulpotomies. This review outlines how the human body reacts to formaldehyde exposure, how recent data has relooked at the issue of carcinogenicity and leukaemia associated with formaldehyde, and whether it is possible to quantify the amount of formaldehyde produced by endodontic cements. The review analyses the way formaldehyde is produced from epoxy resins and addresses the question of whether the amount of formaldehyde from endodontic cements is large enough to override the body's ability to deal with its own endogenous levels of formaldehyde and should the amount of formaldehyde produced be a concern.