A new approach for the restoration of root filled molars

Objective: The objective of this study was to test a new restoration technique for the restoration of root filled molar teeth with MOD cavity.

Methods: Endodontic access and standard MOD cavities without proximal steps and flat floor were prepared in extracted sound molar teeth with similar dimensions. Group 1 restored incrementally with a filled composite resin (Clearfil AP-X, Kuraray, Japan). A matrix band was secured to ensure interproximal build-up and mesial and distal walls were created with the same filled composite resin in Group 2. A flowable resin (Protect Liner F, Kuraray, Japan) was then applied to the walls and a polyethylene fiber (Ribbond, Ribbond Inc. Seattle WA) was embedded into the bed of flowable resin circumferentially. The teeth were then restored with composite resin incrementally. Sound teeth without preparation and non-restored teeth with MOD preparation were used as control. After finishing, polishing and storing in100% humidity for 24 h. compressive loading of the teeth was performed at a cross-head speed of 2mm/min. Mean load necessary to fracture the samples was recorded as KgF and subjected to analysis of variance (ANOVA).

Results: The mean load necessary to fracture the samples was as follows: Group 1:1685,64 ± 320.36; Group 2:1582,44 ± 380.07; Control 1 (sound teeth): 2907,44; Control 2 (teeth without restoration): 349,68 KgF. No significant difference was observed among the Groups 1 and 2 (p>0.05). When the fracture modes were evaluated, it was observed that fiber use saved the remaining tooth structure and caused more repairable fractures when compared to the other groups.

Conclusion: Fiber use in combination with composite resin saves the remaining tooth structure in root filled teeth with MOD cavity.