Shear bond strength of restorations applied to un-complicated crown fractures: an in vitro study

Fracture Resistance of Incisal Fragments Following Reattachment With Different Techniques in Simulated Crown Fractures

Introduction: The aim of the present study was to evaluate and compare the effect of acidetching and Er, Cr:YSGG laser treatment before the reattachment of incisal fragments in coronal fractures of permanent incisor teeth. Methods: Sixty-six sound human maxillary incisors were randomly divided into 3 groups (n=22). Teeth were embedded in self-cure acrylic resins by leaving one-third of the crowns out, and uncomplicated crown fractures were obtained using an Instron testing device. The fragments were reattached using 3 different procedures and a hybrid resin composite (Z250): Group I: Acid etching + Prime & Bond NT; Group II: Er,Cr:YSGG + Prime & Bond NT; Group III: Er,Cr:YSGG + Acid etching + Prime & Bond NT. The percentages of shear bond strengths were determined by comparing fracture strengths of sound and reattached teeth for 3 groups. All data were analyzed statistically with Kruskal-Wallis H test. Results: Mean fracture strengths of the reattached fragments were between 51.02% and 62.93% of that of the sound teeth in all groups. Group I had significantly higher percentages of shear bond strength values (P<0.05) when compared to group II and group III. No significant difference (P>0.05) was found between group II and group III. Conclusion: The findings of the present study show that Er,Cr:YSGG laser irradiation prior to the reattachment of incisal fragments has a negative effect on fracture strength.

Ten-Year Follow-Up of a Fragment Reattachment to an Anterior Tooth: A Conservative Approach

This report describes the 10-year follow-up data of a patient who underwent fragment reattachment to the maxillary central incisor after coronal fracture with pulp exposure as well as the procedures followed for functional and esthetic adjustments. A 9-year-old female patient presented at the clinic of dentistry at the State University of Rio de Janeiro with a coronal fracture and pulp exposure of the right maxillary central incisor that had occurred immediately after an accident. The intact tooth fragment was recovered at the accident site and stored in milk. The treatment plan followed was to perform direct pulp capping and tooth fragment reattachment. When the patient was 14 years old, adhesion between fragment and remaining tooth was lost, and fragment reattachment was performed. Five years later, the same tooth presented clinical discoloration and absence of sensitivity during pulp vitality tests. Subsequently, a new treatment plan was formulated, which included endodontic treatment, followed by nonvital tooth bleaching and light-cured composite resin restoration. An esthetic and natural-looking restoration was achieved. Tooth fragment reattachment is not a temporary restorative technique and requires functional and esthetic adjustments over time to maintain the biomimetic characteristics of traumatized anterior teeth and predictable outcomes.

Restoring crown fractures by direct composite layering using transparent strip crowns

Traumatic dental injuries are mostly seen at childhood and adolescence. The most common fracture in permanent anterior teeth is crown fracture. Esthetic and easy rehabilitation of these anterior teeth is possible using layering techniques and direct composite resin restorations. Shape, color and surface texture are the most important factors in restoring crown fractures esthetically. This article illustrates how to perform an esthetic composite resin restoration of crown fractures using strip crowns. The technique suggests using a strip crown as a mold for direct resin composite restoration. This provides a cost-effective treatment with operator friendly approach where most outstanding advantage is the minimum chair-side time with a single visit that is very important for young trauma patients.

Preservation of coronal tooth fragments prior to reattachment

BACKGROUND

Reattachment of the tooth fragment is a well-accepted treatment option in dealing with crown fractures. Hydration of the fragment is an important aspect in this treatment. The present study evaluated the effect of storing fragments in different storage media prior to reattachment.

METHODS

Sixty bovine incisors were randomly divided into five groups. The teeth were fractured and the fragments were dried for 48 hours and then immersed in one of the four experimental media (distilled water, milk, egg white, or 50% dextrose solution) for 2 hours. Tooth fragments in the control group were kept dry. The apical segments of the fractured teeth were stored in physiological saline. Fragments were reattached and force was applied on the labial side of the teeth at a 1 mm/min rate until failure.

RESULTS

One-way ANOVA indicated that the storage medium affects bond strength (p = 0.002). Multiple comparison tests showed that the teeth preserved in the 50% dextrose solution and the egg white exhibited significantly higher bond strengths compared to the control group (p < 0.05).

CONCLUSIONS

Preservation of the fractured tooth fragment in egg white or hypertonic solutions results in a higher strength of the bond between the restoration and the tooth as compared to storage in water or dried conditions.