SESSION XIII - RESTORATION dr B.Cerkaski preclinical course ENDODONTICS preclinical course

Restoration of the endodontically treated teeth SESSION XIII - RESTORATION dr B.Cerkaski Restoration of the endodontically treated teeth

SESSION XIII - RESTORATION dr B.Cerkaski Session outline Coronal seal Structural and biomechanical considerations Restoration timing Restoration design Temporary restorations

Objectives of tooth restoration The permanent restoration must: Provide coronal seal Protect the remaining tooth structure Minimize cuspal flexure Satisfy function and esthetics

→ sealer disintegration & bacterial contamination Coronal seal RCT will fail if the obturating materials become exposed to oral fluids lost restoration marginal discrepancy recurrent caries → sealer disintegration & bacterial contamination Restoration (temporary and permanent) provides the coronal seal

Restorative failures Restorative failures commonly include: Cusp fracture Crown-root fracture

Structural and biomechanical considerations STRUCTURAL CHANGES IN DENTIN Root canal treated teeth become brittle, supposedly losing resilience as the moisture content of dentin declines after pulp loss. Changes in collagen cross-linking in dentin is also observed in non-vital teeth.

Structural and biomechanical considerations LOSS OF TOOTH STRUCTURE Teeth after RCT are weakened even by occlusal cavity preparation There is a greater susceptibility to fracture in teeth with caries, trauma or large restorations

Structural and biomechanical considerations BIOMECHANICS Cuspal flexure (especially premolars, molars) can lead to cyclic opening of margins between the tooth and restorative material → leakage, fracture As cavity preparation become larger and deeper – usupported cusps become weaker and show more deflection under occlusal loads

Restoration timing As soon as possible! In teeth requiring restoration of only the access (f.e. minimally restored anterior teeth) the final restoration is best placed immediately after obturation (temporary restoration protect against bacterial contamination but do not provide complete protection against occlusal forces) It may be necessary to defer the restoration but the delay should be minimal

Indications for delaying final restoration Questionable prognosis (where failure would lead to extraction) Use of tooth as a bridge abutment may demand evidence of healing before an expensive prosthesis is placed Only few indications justify delaying restoration!

Principles of restoration design CONSERVATION OF TOOTH STRUCTURE – further dentin removal should be minimized but cuspal reduction may be necessary RETENTION – the coronal restoration should be retained by remaining dentin or the post and core. PROTECTION OF REMAINING TOOTH STRUCTURE – protection of unsupported cuspsto minimize the flexure and fracture

Restoration designs DIRECT RESTORATIONS /composite, amalgam/ INDIRECT RESTORATIONS /onlays, prosthetic crowns/

Direct restorations - indications Minimal tooth structure lost before and during RCT Uncertain prognosis Ease of placement and cost

Direct restoration (composite)

Direct restoration (composite)

Direct restoration (composite)

Direct restoration (composite)

Direct restoration (composite)

Direct restoration (composite)

Direct restoration (composite) Another case: tooth 36 after RCT (temporary filling)

Direct restoration (composite) …after removal of temporary filling

Direct restoration (composite) …adhesive procedure + wall restored

Direct restoration (composite) …final effect

Direct restoration (composite) Another case: tooth 36 Tooth 36 after RCT

Indirect restorations Cast restorations provide the greatest occlusal protection and are optimal if there is extensive loss of tooth structure Full crown is a reliable and strong restoration that protects against crown-root fractures. In this situation a post and core must be placed!

Indirect restoration (composite)

Indirect restoration (composite overlay)

Indirect restoration (porcelain inlays / onlays) Another case: teeth

Post and core + prosthetic crown

Objectives of temporization Different materials are required depending on: Time Occlusal load and wear Complexity of access Loss of tooth structure

Temporary restorations Must do the following: Seal coronally, preventing ingress of oral fluids and bacteria and egress of intracanal medicaments Enhance isolation during treatment procedures Protect tooth structure until the final restoration is placed Allow ease of placement and removal

Temporary restorations Premixed cements (CAVIT, COLTOSOL, PROVIDENT) Intermediate restorative materials (IRM) Glassionomers Temporary endodontic restorative materials (TERM)

Temporary restorations

Technique for temporization cotton pellet 3-4 mm of temporary material are required! Minimal space should be occupied by cotton pellet

Technique for temporization The „blob” technique is wrong because it does not seal the walls. The incremental technique which adds succesive layers, pressing against the chaber walls is correct.

… thank you for your attention…