Fracture resistance of root filled molar teeth restored with glass fibre bundles

• Published in: International endodontic journal Vol. 43; no. 5; pp. 356 - 362
• Main Authors: Rodrigues, F. B., Paranhos, M. P. G., Spohr, A. M., Oshima, H. M. S., Carlini, B., Burnett Jr, L. H.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01-05-2010
• Subjects: Acid Etching, Dental; Bisphenol A-Glycidyl Methacrylate - chemistry; composite resin; Composite Resins - chemistry; Compressive Strength; Dental Cavity Preparation - methods; Dental Enamel - injuries; Dental Materials - chemistry; Dental Pulp Cavity - injuries; Dental Restoration, Permanent - methods; Dental Stress Analysis - instrumentation; Dentistry; endodontic therapy; fracture resistance; Glass - chemistry; glass fibre; Glass Ionomer Cements - chemistry; Gutta-Percha - therapeutic use; Humans; Maleates - chemistry; Materials Testing; Molar - injuries; Molar - pathology; molar teeth; Root Canal Filling Materials - therapeutic use; Root Canal Therapy - methods; Stress, Mechanical; Tooth Fractures - physiopathology; Tooth, Nonvital - therapy
• DOI: 10.1111/j.1365-2591.2009.01666.x
• EISSN: 1365-2591
• ISSN: 0143-2885

Rodrigues FB, Paranhos MPG, Spohr AM, Oshima HMS, Carlini B, Burnett LH Jr. Fracture resistance of root filled molar teeth restored with glass fibre bundles. International Endodontic Journal, 43, 356–362, 2010.
Aim  To evaluate the effect of unidirectional or woven glass fibre tapes inserted into MOD cavity preparations on the fracture resistance of root filled molar teeth.
Methodology  Extracted human molar teeth were randomly divided into six groups (n = 15) : G1 – sound teeth, control; G2 – MOD cavity preparation; G3 – MOD + root canal treatment (Endo); G4 – MOD + Endo + composite resin restoration (Resin); G5 – MOD + Endo + unidirectional fibre (UF) + Resin; G6 – MOD + ;Endo + woven fibre (WF) + Resin. The teeth were subjected to a compressive fracture test in a universal testing machine. After testing, two failure modes were classified: pulp chamber floor or cusp.
Results  The highest and the lowest mean fracture strengths were found in sound teeth (G1) (4960N) and MOD + root canal treatment (G3) (612.84N), respectively, with significant differences from the other groups (P < 0.05). The remaining groups had statistically similar means. In G5 and G6, there was a tendency for fracture to occur in the pulp chamber floor compromising tooth integrity.
Conclusions  The insertion of glass fibres into MOD cavity preparations and restoring them with composite resin was not different than molar teeth filled with composite resin only in terms of fracture resistance. Fibres placed into MOD cavities do not reinforce teeth.