Fracture strength and fracture patterns of root filled teeth restored with direct resin restorations

N A Taha, J E Palamara, H H Messer
Journal of Dentistry 2011, 39 (8): 527-35

OBJECTIVE: To compare fracture characteristics of root-filled teeth with variable cavity design and resin composite restoration.

METHODS: 80 extracted intact maxillary premolars were divided randomly into eight groups; (1) intact teeth; (2) unrestored MOD cavity; (3) unrestored MOD cavity plus endodontic access through the occlusal floor; (4) unrestored MOD plus endodontic access with axial walls removed; (5) MOD restored with resin composite; (6) MOD plus endodontic access, resin composite; (7) MOD plus extensive endodontic access, resin composite; (8) MOD plus extensive endodontic access, GIC core and resin composite. A ramped oblique load was applied to the buccal cusp in a servohydraulic testing machine. Fracture load and fracture patterns were recorded. Fracture loads were compared statistically using 1-way ANOVA, with Dunnett test for multiple comparisons.

RESULTS: Unrestored teeth became progressively weaker with more extensive preparations. Endodontic access confined within the occlusal floor did not significantly affect strength compared to an MOD cavity. Loss of axial walls weakened teeth considerably [292+80N vs 747+130N for intact teeth]. Restoration increased the strength of prepared teeth particularly in teeth without axial walls. Teeth with a GIC core were not significantly weaker than intact teeth [560+167N]. Failures were mostly adhesive at the buccal interface, with the fracture propagating from the buccal line angle of the occlusal floor (MOD and MOD plus access groups) or of the proximal box (axial wall removed).

CONCLUSIONS: Direct restorations increased fracture resistance of root filled teeth with extensive endodontic access. Both restored and unrestored teeth showed similar fracture patterns.

Full Text Links

Find Full Text Links for this Article


You are not logged in. Sign Up or Log In to join the discussion.

Related Papers

Remove bar
Read by QxMD icon Read

Save your favorite articles in one place with a free QxMD account.


Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"