Comparative evaluation of fracture resistance using two rehydration protocols for fragment reattachment in uncomplicated crown fractures

Abstract

Background/aims: Uncomplicated crown fracture is the most common traumatic dental injury. The International Association of Dental Traumatology has recommended fragment reattachment as the best method for restoring uncomplicated crown fractures of permanent teeth. Dehydration can affect fracture resistance after reattachment. However, a standard protocol for rehydration is still lacking. Hence, the aim of this study was to design a humidification chamber and assess its efficacy for improving the rehydration of tooth fragments and increasing fracture resistance after reattachment.

Materials and methods: Sixty mandibular bovine incisors with similar dimensions and free of any structural deformities were fractured and randomized into five groups: Group I, Control Group (sound teeth); Group II (dehydrated for 24 hours); Group III (rehydrated in distilled water for 15 minutes); Group IV (rehydrated in a humidification chamber for 15 minutes); and Group V (restored with composite). A humidification chamber was designed and used for rehydration for 15 minutes in Group IV. Fragments in Group III were immersed in distilled water for 15 minutes. Reattachment procedures and materials remained the same in all groups. Fracture resistance was tested in a universal testing machine, and statistical analysis was done by Stata-14.

Results: The Control Group with sound teeth (Group I) exhibited a maximum value of 282 ± 10.32 N, while Group II (fragment reattached without rehydration) had the least fracture resistance, 49.75 ± 5.2 N. Rehydration by means of the humidification chamber protocol (Group IV) resulted in significantly higher fracture resistance (150.54 ± 6.49 N) than in Group III (rehydration by means of immersion).

Conclusions: Fracture resistance after fragment reattachment was significantly affected by the rehydration of fragments for 15 minutes in the humidification chamber. Fragment reattachment after rehydration showed better fracture resistance than the composite restorations.

Keywords: crown fracture; fragment reattachment; humidification; rehydration.