Limitation of contemporary Endodontic treatment

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1 Limitation of contemporary Endodontic treatment Aetiology - MO Micro-organisms Biofilm Maria Lessani Objectives of Endodontic treatment? Changes in our understanding During RCT: CHEMO-mechanical preparation Rubber dam, Sodium hypochlorite, interappointment dressings, aseptic handling of instruments and material Obturation of the RC system What are we fighting Antibiotic resistance Biofilm challenges New names for old bugs New bugs Changes in nomenclature Advances in microbiology Current names for old bugs Identified so far Nomenclature Changes (e.g. Black pigmented Bacteroides» Porphymonas, Prevotellas) 1

2 Microbial resistance Makela 1994 In medicine In dentistry we have been criticised for over prescribing systemic AB In medicine we are now actually facing a threatening phase in microbial evolution: too many microbes have learnt to resist too many of our antimicrobial drugs. And we are behind in inventing new ways to combat them.... Many of these pathogens are now resistant to most available drugs, and the patients die of these infections like they did before the antibiotic era. Role of systemic antibiotics Prophylactic use in patients susceptible to bacterial endocarditis. NICE guidelines in UK...NO LONGER! Prescribed as an adjunct to other treatment procedures against acute infection with signs of systemic involvement. Over prescribing of systemic AB FGDP publication very useful for GDP April 2012 Health protection agency guidance Increased dose of Amoxicillin for Mx of infections in adults 500mg every 8hrs, doubled in severe infections Host response Operator skill We cannot control Healing after Endodontic treatment can occur with first year to even 10 yrs after Technically demanding Challenge of micro-organisms 2

3 Iatrogenic errors The more errors the more problems most common iatrogenic errors are; blocking canals and the consequences e.g. ledges, perforations, fracturing instruments Access problems Adequate access should involve removal of; caries leaking cast restorations looking for fractures removal of roof of pulp chamber Preparation problems Blockages Ledges Zip Elbow Perforations 3

4 Obturation problems Leakage problems Length issues; short Long Density issues; Voids Pulp chamber Coronal seal Leakage Post op leakage Lack of core Lack of coronal seal 4

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7 Limitation of obturation materials Breakdown of seal Especially with coronal leakage New obturation materials Resin based e.g. Resilon Bioceramic based e.g. Endosequence 1 visit or more? Controversial Outcome studies equally divided Nair et al (Feb issue of OOO) Mexico 1 visit RCT (1 RC rotary and 1 RC hand preparation) Immediately root end surgery Section of the root tip (histology, SEM) 7

8 Periradicular surgery Rationale: To eliminate persistent periradicular disease where it is not possible to do this by non-surgical means Objectives Remove diseased periradicular tissue Expose apical portion of root Seal the RC system effectively Retrograde approach - latest development Magnification operating microscope microsurgical instruments Root-end preparation angle of bevel design and depth of retrograde cavity ultrasonic retro-preparation Root-end filling materials Fine hydrophilic particles composed of MTA Tricalcium silicate No iron Holland et al (2002) + CXD? Hernandez et al (2005) Tricalcium aluminate Tricalcium oxide Silicate oxide Bismuth oxide (opacity) Courtesy of A Hoskinson 8

9 Causes of failure Residual intraradicular bacteria Extra-radicular infection Bacterial recontamination (by coronal leakage, root fracture/perforation) Foreign body reaction True cyst Siqueira 2001 (Review) Common factors affecting prognosis of endodontic treatment The presence of pre-operative lesion The length of root filling The level of instrumentation The quality of coronal restoration The shape of canal preparation Factors affecting prognosis of surgical treatment Quality of pre-existing root filling Placement of a root-end filling Presence and size of PA lesion Coronal restoration Management of failure - principle Remove the source of infection Prevent recontamination Preservation of coronal and radicular dentine to retain and support coronal restoration. Management of failure - approaches Reports on treatment results 94-96% Partial pulpotomy (Cvek, 1978, 1993) Orthograde approach (via crown) indicated for incompletely cleaned canals, missed canals, restorative need, defective coronal restoration Retrograde approach (via root end) indicated for extra-radicular infection, inaccessible via orthograde approach 86-96% rate of success of conventional root canal treatment. (Sjogren et al., 1990, Ng et al. 2011) 62% - 75% of the previously root treated teeth healed after retreatment. (Sjogren et al., 1990, Ng et al. 2011) 60% of success by surgical retreatment. (Allen, 1989). 91% Microsurgery (Kim et al., 2001) 9

10 Cause of disease micro-organisms 10

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