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Pre-endo restoration Dr Eason Soo DDS (UKM), MDS Endo (HK), AdvDipEndodont (HK), M Endo RCS (Edin)

Lecturer/Clinical Specialist in Endodontics Dept. Operative Dentistry, Faculty of Dentistry, UKM

Real clinical case




Learning objective: Describe the significant of determining tooth restorability prior to endodontic treatment Describe the different methods available to determine the restorability of the tooth Describe and perform the methods used to isolate a severely broken down teeth prior to endodontic treatment Describe and perform various techniques of temporization of severely broken down teeth

What is ferrule? “Ferrule� is a metal ring or cap that strengthens the end of a handle, stick, or tube to prevent it from splitting or wearing (Oxford Dictionary). The word probably originated in early 17th century from combining the Latin for iron (ferrum) and bracelets (viriola)

What is ferrule? (cont..)

In dentistry, ferrule refers to a band of cast metal (or a crown) encircling the coronal tooth structure It has been proposed that the presence of a ferrule would help the tooth to resist occlusal stresses and contribute the structural integrity of a root treated tooth by providing appropriate resistance form

What is ferrule? (cont..) A 2 mm of minimal ferrule length of coronal tooth structure (usually visible after crown preparation) was suggested as an acceptable dimension (Jotkowitz & Samet 2010, BDJ) Recent literature review on ferrule effect suggested that 1.5 to 2 mm ferrule length has a positive effect on fracture resistance of root filled teeth (Juloski et al 2012, J Endod)

Restorability and prognosis assessment

Coronal tooth loss or crack – restorable? Caries Trauma Cavity preparation Crown preparation Erosion & attrition

Prognosis factor





PPD ≤ 3 mm, BoP-, PAL loss ≤ 25 %, FI degree ≤ I

Residual PPD ≥ 6 mm & BoP+, PAL loss of approx. 50 %, FI degree II or III, root proximity

Insufficient residual attachment

No clinical signs & absence of or decreasing radiolucency

No clinical signs & persisting radiolucency

Symptomatic situation & radiolucency, no further treatment feasible


(for root treated cases)


Insufficient residual tooth Sufficient residual tooth substance, Reduced substance adequate retention & resistance forms retention/resistance form (< 1.5 mm circular (ideally 4 mm wall-height with 15º– (< 3 mm wall-height and/or ferrule), no crown 20º convergence angle, > 25º convergence angle lengthening or ortho 1.5 to 2 mm ferrule height extrusion feasible

PPD: probing pocket depth; BoP: bleeding on probing; PAL: probing attachment level; FI: furcation involvement (degree 0 to 3)

Zitzmann et al 2010 J Prosthet Dent

Pre-endo restoration Bacterial is the main causes for pulpal & periapical disease Maintaining optimal seal during inter-appointment temporary filling during the course of endodontic treatment is mandatory Coronal leakage will occur through dislodgment of temporary filling and/or weaken tooth structure

..Pre-endo restoration restorability assessment require removal of pre-existing restoration impossible to obtain adequate isolation with rubber dam or to allow retention of an inter-appointment temporary filling facilitate isolation, minimized leakage of irrigant, infection control provide provisional core prior to starting root canal treatment reduce incidence of tooth fracture during the course of endodontic treatment core build-up with matrix band, or copper band tooth banding with orthodontic band â&#x20AC;&#x201C; reduce cuspal flexure, double tooth fracture resistance & retention of temporary core build-up material One or more cusps missing (esp. premolars), orthodontic banding is indicated occasionally gingival electrocautery â&#x20AC;&#x201C; temporary measure aesthetic zone, consider masking orthodontic band with composite resin

Criteria for acceptable pre-endo core restoration build-up with orthodontic band: remove all restoration & caries from tooth select well fitting ortho band place cotton pellet directly over canal orifices to prevent cement entering; make sure cotton pellet is well away from cavosurface margin burnish gingival margin of the band cement ortho band with GIC luting cement restore tooth with GIC e.g. Fuji 7 or Fuji 9 prepare access cavity, remove cotton pellet, & commence root canal treatment

Orthodontic bands

Banding kits

Band remover

Mershon band seater

Band seater

Temporization with “Double seal” IRM Cavit

Cotton pellets

Function of “double seal” Cavit as the deeper layer material inside the pulp chamber & access cavity IRM as the outer layer which is exposed to loading and the oral cavity Outer layer of IRM is an antibacterial agent, less soluble, wears less and is stronger Inner layer of Cavit prevents any moisture (i.e., saliva) from reaching the root canal system if it has been able to penetrate through the IRM margins •


Jensen et al 2007

Real clinical case Restorable??





Premolar: Pre-endo restoration with Fuji 9/Ketac Molar and ortho band, with GIC/CR masking on the buccal surface Molar: Pre-endo restoration with Ketac Silver and ortho band

Chronic apical abscess 14

14 14 Pre-endo restoration with GIC & copper band





Old AR removal & GIC build-up

Orthodontic banding

Copper band

How about this? 46 46

Crack line on DB aspect

Temporary aluminum crown

Tips after completion of RCT (obturation) prior to permanent core build-up obturation + orifice seal remove all previously restored GIC material leave the ortho band in place may leave very thin layer of GIC attached on the inner side of ortho band radicular composite resin/amalgam core foundation aforementioned thin layer of GIC will be removed during crown preparation rational: maintain optimal coronal seal during permanent core build-up

Thank you....

Pre-endo restoration 2013-2014