Fig.1
Enamel-Dentin crown fracture of tooth 2.1 in a 9 years old boy. Vitality test with response to stimulus. Note how tooth 1.1 still has black debris due to the accident.
In coronal fractures, as the color change of the fragment after reattachment is not a frequent problem, the major disadvantage in comparison to direct composite restorations is the uncertain duration of the fragment adhesion to the tooth. Crowns which are fractured and restored with only composite in comparison with fragment reattachment, offer in long term studies, a superior retention. (2-3). Aesthetically speaking some authors describe worst aesthetic results with composites, justifying the use of the fragment reattachment technique. As we know the aesthetic results achievable with composites are excellent. What could justify the fragment reattachment technique instead of direct composite is the chair time and costs because good quality direct anterior composite takes as an average 1 hour (if the young patient collaborates which is not always) and fragment reattachment can be done in only 15 minutes, diminishing a lot the costs and efforts to achieve the same result.

Fig.2
Partial tooth fragment. We checked the adaptability of the fragment to the dental surface. Place the fragment on a guttapercha or wax stick to handle in an easier way. Don’t polish the fragment neither the tooth to allow better adaptation.
By phone, we asked the mother to keep the tooth hydrated in tap water. The partial fragment brought by the mother of the patient was analyzed, the fit was checked and even though it was incomplete, it was of extreme help for the direct build-up.
The main goal concerning enamel and dentin fractured anterior teeth is to maintain the vitality, as we know from the classical study from Kakehashi (4) that the pulpal exposition to bacterial plaque produces necrosis, so when we have to deal with an enamel-dentin fracture the first thing to do is to disinfect the dentin with chlorhexidine 2% (pure chlorhexidine without stains) (5) and seal the dentin tubules with a restoration the earliest possible.

Fig.3
The attached fragment was thin (only the palatal fragment) and the rest had to be rebuild with resin composite but the natural tooth was useful because almost all the original shape was maintained and no impressions and wax-up was necessary.
If the fragment is incomplete it is possible to reattach the partial fragment (if its possible to adapt the fragment to the tooth) and complete the buccal build-up with direct composite. It is the situation of the following clinical case. The clinical steps was: clean the fragment and tooth with 2% chlorhexidine to eliminate contaminants, then elimination of cutting enamel (only buccal in that case so the fragment maintains its fitting on the palatal) with a contouring disk (Sof-Lex orange, 3M), 37% orthophosphoric acid etching for 30 sec on enamel and 15 sec on dentin, 2% chlorhexidine again to inhibit the MMPs, adhesive, the partial fragment was attached using a very small amount of a regular composite on both surfaces, fragment reposition then polymerization.

Fig.4
With the same composite a layer of dentin color was placed, and before the 0,5 mm enamel was placed some white stains were placed. Enamel was placed accordingly to the remaining space (0,5 mm). Afterwards, finishing and polishing steps were performed.

Fig.5
The finished restoration after one month control shows good integration and the vitality test were normal both in 11 and 21.

Fig.6
Situation before and after. Semester controls are required to monitor pulp vitality.
The risk of pulp necrosis in enamel-dentin fractures in permanent teeth, independently of fracture extension and type of treatment, is among 1-6% (6). So controls must be done regularly to check the vitality.

Conclusions

Having a perfect tooth fragment or a wax-up is not always possible, in order to seal immediately the dentin in traumatized teeth we must make everything possible to complete the restoration without further intervention.

Bibliography

1. Andreasen JO. Adhesive dentistry applied to the treatment of traumatic dental injuries. Buonocore Memorial Lecture. Oper Dent. 2001; 26,328-35.
2. Smales RJ, Webster DA, Leppard PI. Survival predictions of four types of dental restorative materials. J Dent 1991; 19:278-82.
3. Robertson A. A retrospective evaluation of patients with uncomplicated crown fractures and luxation injuries. Endod Dent Traumatol 1998; 6:245-56.
4. Kakehashi S, Stanley HR, Fitzgerald RJ. The effects of surgical exposures of dental pulps in germ-free and conventional laboratory rats. Oral Surg Oral Med Oral Pathol. 1965; 20: 340-9.
5. Pameijer CH, Stanley HR. The disastrous effects of the “total etch” technique in vital pulp capping in primates. am J Dent. 1998; 11: S45-S54.
6. Andreasen JO, Andreasen FM. Textbook and color atlas of traumatic injuries to the teeth. 3rd ed. St.Louis: Mosby Year-Book ; 1994.