Fragment reattachment or direct restoration? An in vitro study.

BACKGROUND/AIM: The fracture resistance of teeth subjected to fragment reattachment may improve when the technique is performed using intermediate materials. The aim of this study was to evaluate the influence of different bonding materials, including pre-heated composite resin, on the fracture resistance of teeth subjected to the reattachment technique compared with a direct composite resin restoration. MATERIALS AND METHODS: After simulating a tooth fracture, each specimen was reattached by using one of the following intermediate materials (n = 15): G0, negative control (sound teeth); G1, Z100; G2, pre-heated Z100; G3, Filtek Z350 XT; G4, pre-heated Filtek Z350 XT; G5, Filtek Z350 XT Flow; and G6, RelyX Veneer. In G7, direct class IV restorations were performed using Filtek Z350 XT composite resin. The fracture resistance was evaluated using a universal testing machine under a compressive load of 1 mm/min. One-way analysis of variance (ANOVA) and the post hoc Tukey test (5%) were conducted. RESULTS: G0 showed the highest fracture resistance, and this was statistically different from the other experimental groups (p < .05) except for G2 and G4, in which the fragments were bonded using pre-heated resins. A statistically significant difference was found between groups G1 and G6 (one-way ANOVA, p = .04). For G1 and G2, a significant difference was found between bonding with and without pre-heating (p < .05). This difference was not observed in G3 and G4 (p > .05). No statistically significant difference was found between the reattached and directly restored groups (t-test, p = .53). CONCLUSIONS: The tooth reattachment technique using pre-heated composite resin showed fracture resistance values similar to those of the sound tooth group. No difference was found between the fragment reattachment and direct composite resin techniques.

Reattachment of fractured teeth using a multimode adhesive: Effect of different rewetting solutions and immersion time.

BACKGROUND/AIMS: Following coronal tooth fracture, keeping the fragment hydrated is of the utmost importance in the tooth fragment bonding technique. The aim of this study was to evaluate the effects of different immersion times in different storage media on multimode adhesive bonding between reattached fragments and teeth. MATERIALS AND METHODS: A total of 195 bovine incisors were fractured and randomized into the following storage groups (n = 15): G0-control group (sound tooth); GA-saline solution: for 1 hour (A1) or 24 hours (A2); GB-artificial saliva: for 1 hour (B1) or 24 hours (B2); GC-coconut water: for 1 hour (C1) or 24 hours (C2); GD-tap water: for 1 hour (D1) or 24 hours (D2); GE-milk: for 1 hour (E1) or 24 hours (E2); GF-dry (dehydration): for 1 hour (F1) or 24 hours (F2). Tooth fragments were then reattached using a multimode adhesive in a self-mode technique with a flowable resin composite. Fracture resistance was evaluated in a universal testing machine under a compressive load (1 mm/min). The data were submitted to two-way analysis of variance and the post hoc Tukey test (5%). RESULTS: The group submitted to the dehydration factor (GF) exhibited a mean value of 599.1 ± 144.2 N, while those submitted to all hydration protocols (GA, GB, GC, GD, GE) exhibited a mean value of 751.8 ± 285.4 N. Dehydration significantly affected the fracture strength values (P = .005). No significant interaction between the rewetting solutions was observed (P > .05). CONCLUSIONS: Hydration of the tooth fragment increased fracture resistance, regardless of the storage solution and/or immersion time.