In vitro fracture resistance of root amputated molar teeth restored with overlay

Pilot study

Abstract

Background: The purpose of this study is to evaluate the effect of different amount of periodontal support around root amputated maxillary root canal treated molar teeth restored with overlay restorations.
Methods: Fourteen extracted and root canal treated maxillary molars were used. Standard sized MOD cavities were prepared and subsequently the teeth received core build-up and overlay restorations. The restored teeth underwent root amputation of the mesiobuccal roots. The specimens were divided into two groups depending on the amount of periodontal support around the remaining roots. The specimens were submitted to static fracture resistance test. Fracture thresholds and fracture patterns were measured and evaluated.
Results: The fracture resistance of root amputated teeth with sound periodontal support yielded higher fracture resistance (mean = 2655,53 N, SD = ±1107,27 N, n = 7) than the ones with damaged periodontal support (mean = 1624,12 N,
SD = ±535,03N, n = 7) Regarding the fracture pattern of latter group all the samples exhibited unfavourable fractures, whereas the ratio of favourable and unfavourable was approximately the same in the group with sound periodontal support.
Conclusions: Within the limitations of this study, the amount of periodontal support seems to show some correlation with the fracture resistance of root amputated and restored maxillary molars. It had a positive impact on the fracture pattern of these teeth as well. Thus the amount of periodontal support can be a key element regarding the success rate of root amputated maxillary molars and can influence also the decision making process of the operator.