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In Vitro Fracture Resistance of Adhesively Restored Molar Teeth with Different MOD Cavity Dimensions
Author(s) -
Forster András,
Braunitzer Gábor,
Tóth Máté,
Szabó Balázs P.,
Fráter Márk
Publication year - 2019
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/jopr.12777
Subject(s) - molar , materials science , dentistry , fracture (geology) , post hoc , tooth fracture , orthodontics , mandibular second molar , composite material , medicine
Purpose Molar MOD (mesial‐occlusal‐distal) cavity preparation weakens relative cuspal stiffness by up to 63%, often resulting in cuspal fracture. This investigation inspects fracture resistance of MOD cavities restored using direct composite restoration. Materials and Methods 120 extracted, intact mandibular molars were selected. MOD cavities with different depth/wall thickness were prepared in 9 groups (n = 12): A: 3 mm/3.5 mm, B: 3 mm/2.5 mm, C: 3 mm/1.5 mm, D: 5 mm/3.5 mm, E: 5 mm/2.5 mm, F: 5 mm/1.5 mm, G: 7 mm/3.5 mm, H: 7 mm/2.5 mm, I: 7 mm/1.5 mm. Specimens with 7 mm deep cavities received root canal treatment. The teeth were restored with dental composite. Maximal fracture strength test was conducted. Intact natural teeth were used as control. For statistical analysis Kruskal‐Wallis ANOVA with post‐hoc pairwise comparisons was used (α = 0.05). Results Significant difference was indicated between the control and groups D, E, F, G, H, and I. No significant differences were found between the A, B, C groups and the control. Comparing the 5 and 7 mm cavity depth groups, there was no statistical difference between any of them. Conclusions Within the limitations of this investigation, the following conclusions can be drawn regarding molar teeth with a MOD cavity: 3 mm or shallower cavities can be restored to the physiological fracture strength with direct composite restorations; 5 mm or deeper cavities cannot be restored to the physiological fracture strength with direct composite restorations. Cusp thickness does not significantly influence fracture strength in molar MOD cavities with a direct composite restoration.