Modern day bonding procedures has now made it possible to treat cases of trauma to the anterior teeth instantaneously if the broken fragments are immediately available. This is a case report by Dr. Anupama Patil on the treatment of a broken anterior tooth fraagment.

ANTERIOR TOOTH FRAGMENT REATTACHMENT

A very common occurrence in dentistry is the fracture of anterior teeth due to some kind of traumatic injury during play or work. An uncommon component of this occurrence is the intact availability of the fracture piece or fragment. Over 90% of the times the fractured component is either crushed or lost. In a review of literature, there have been very few studies done in which a large number of cases are available demonstrating reattachment of a broken fragment to an anterior tooth. Most of the studies include procedures like direct build ups, crowns and veneers for evaluating the long term post operative success in the treatment for anterior crown fractures.

A fragment reattachment procedure offers certain advantages over the above mentioned procedures. It allows immediate treatment and the patient can generally get back his or her broken tooth repaired in less than an hour from the time of injury, especially if there is no immediate endodontic therapy required. The overall aesthetic appearance of the natural tooth will generally always score over a resin build up, especially in terms of translucency and and light transmissions. On the other hand, in the hands of a skilled and artistic aesthetic dentist, results can be obtained which tend to be much superior to even the prior natural appearance.

Literature reviews reveal attempts having been made to restore broken down posterior teeth with segments of tooth structure cut out from extracted third molars and bond the piece into the broken down tooth. The technique was published by Santos and colleagues way back in 1991 using resin cements with the enamel etch technique. Another technique tried for posterior tooth fractures was the reattachment of broken cusps with resin cements. This was reported by Jackson in 1993. The long term success rate of such attempts again has been not easily available.

Due to the paucity of available studies and even individual case follow ups over a number of years, there is some amount of scepticism about the procedures that can be used for carrying out fragment reattachments. Empirical evidence coming in from private clinical practices and individual dentists coupled with the fact that the fragment reattachment will not cause any deleterious effects makes it a standard procedure, especially if the fragment approximates properly. Academicians have viewed this treatment modality more as an interim procedure rather than a permanent treatment plan. The key issue is how long is the interim period. Most purported permanent dental treatment plans have to undergo maintenance and repair over 6 to 8 years time. If such reattached fragments last 6 years or so it is much more than interim.

In fact a number of laboratory studies done by Andreasen and colleagues have changed this line of thought. They showed that when veneers or direct buildups are done on teeth with reattached fragments, the overall fracture resistance of the crown is much higher than on teeth with fragments reattached. Even when compared to intact incisors, they showed either the same fracture resistance or in some instances a greater resistance to fracture.

Demarco and Powers, in another study, fractured bovine anterior teeth in the laboratory and then re-attached the fragments. These fragments were then checked for fracture resistance and compared with other fractured teeth as well as intact teeth. The reattached teeth showed greater fracture resistance than t he fractured teeth along the lines of the previous study. In fact the fracture resistance was again, equivalent to that of intact teeth.

1. Assessment of the Tooth and the fragment – approximation – intactness
2. Fragment to be attached or not
3. Take IOPA
4. Place the fragment in a cleanser
5. Prepare tooth and fragment – beveling
6. Rehydrate and keep in water
7. Micro etch the fragment on the attachment side
8. Isolate the tooth in the mouth
9. Cavity cleanser – Tooth and fragment
10. Etch – Tooth and fragment
11. Aqua Prep – Both
12. Dentin Bond – Both
13. Polymerize – Both
14. Luting with a dual cure resin (Only the base may be used)
15. Bonded the fragment back
16. Check for blending of proximal surfaces
17. Build up the fractured groove with direct composite for blending
18. Polishing
19. Checking for the Occlusion.
20. Instructions
21. Recall – Check for rehydration, examination, polish if required. (After two days)
22. Recall - One month (IOPA)
23. Recall - Six months (IOPA)

A young 12 year old girl presented with a traumatic injury to the upper left central incisor while playing. She hit the tooth against a vertical bar of a swing and fractured a semi traiangular portion of her tooth. The fragment was easily locatable and the patient’s mother wrapped in a piece of cotton and called up the clinic. She was asked to immediately report to the dental office and within 35 minutes of the accident occurring the patient was on the dental chair.

A complete history of the incident was taken and then an elaborate clinical examination of the tooth and the rest of the dentition was carried out. Subsequent to this, an IOPA was taken. The IOPA showed no pulp involvement at the fracture line nor was any fracture lines seen in the root area. At the same time an associate had taken the fragment and cleansed it in the ultrasonic bath and then kept it for rehydration in filtered water.

After the gross initial examination the tooth in question was examined in detail. The tooth was found to be vital and very much firm and in its original position. There was absolutely no discernable mobility and the patient was not experiencing any great distress or pain in the tooth. There was only a very mild tenderness when extreme pressure was applied to the tooth. In all other aspects the tooth did not show any other pathology. All the other teeth were examined and no craze lines or fractures were found in any other area of the mouth.

Then the fragment was examined and it showed a very small amount of damage in one corner. It was checked from all sides for any foreign bodies or debris and any tooth powder that might have been generated during the injury. Once the cleanliness of the fragment was ascertained it was placed on the tooth and approximated at the area of cleavage. It was noticed that the fragment approximated very well with the fractured area and was seating quite comfortably. It was noticed that there was a very small marginal corner, which had evidently been lost.

After detailed observation and further evaluation of the photographs it was noticed that there was some minimal tooth structure which has been crushed at places along the fracture line and that the break was not a clear cut. Hence a decision was taken to incorporate a small bevel at the fracture line so that it could be masked with a direct bonding procedure which would also help in blending the fragment seamlessly with the tooth.

The fragment was then handed over for final cleaning and micro-etching. The micro etching procedure is to be carried out only on the area which has to be bounded. The fragment was cleaned once more and then very carefully microetched as per the directions. Then the microetched area was blow dryed and cleaned once again. Then the bonding surface was acid etched and then subsequently the acid was washed off and the surface dried without dessicating. Then bonding agent was applied on the etched area and dried after 30 seconds. One Step bonding agent from BISCO was used as the bonding agent for the fragment as well as the tooth. The fragment was now ready for the reattachment procedure.

In the mean time the central incisor was isolated. A rubber dam was not necessary since the patient was very co-operative. Cheek retractors coupled with a retraction cord and matrix strips on the proximal surfaces of the tooth were sufficient to achieve complete isolation. After placing the cord and the matrix strips the tooth was cleansed with aqua prep. On close observation it could be seen that there was almost a pin point exposure seen on the fractured surface. The area was thoroughly cleansed and then a total etch procedure was carried out. The pin point pulp area was not etched. Then the acid etch was washed away carefully, making sure that the etch was carefully taken away with the high vac suction. Once the etching was complete and the excess water washed away, the surface area was coated with the bonding agent. After the customary wait for the base material to evaporate and dry away for about 30 seconds, the area was blow dried to avoid pooling of the bonding agent in any particular location. Then the surface was polymerized with the curing light and the fragment was tried out once and then returned.

The proper shade of a dual cure bonding agent was then selected. The material used was Choice from BISCO. The dual cure was mixed and then applied to both the tooth surface as well as the fragment and then the fragment was placed in the appropriate position and sufficient pressure applied to hold it in place. Then the excess material was carefully wiped out without spreading it too much. Once the excess had been removed the chair side assistants polymerized the dual cure cement from both sides. After adequate application of the light the dual cure had completely polymerized and the fragment was now held in place.

The next step was to now mask the fracture line with composite material. The appropriate shade was selected from the Esthetic X kit and the fracture line was closed up and the fragment was blended in with the main tooth structure. The material was blended in over the beveled areas. A very appropriate method of blending in the material was done with a special silicone tip instrument which was used for handling the composite.

The next step was to finish and then polish the composite material. A profin system was used to finish the proximal surfaces and regular composite finishing burs were used to recreate the high gloss of natural enamel. This entire procedure took about 40 minutes. The patient thereby had the original look and the tooth back within close to 1 hour of time. The patient was then given the appropriate instruction to be able to maintain the fragment for a long period of time. The next appointment was given for the patient to report back after 4 days. It was necessary to make an assessment on this appointment as regards the prognosis of the tooth as well as the prognosis of the fragment reattachment.

The patient reported back after 3 days and the final polishing was then completed. A very small speck of excess material which had stuck to the proximal surface was removed and the entire labial surface polished very thoroughly. The patient reported that she was very comfortable and felt no pain or any untoward symptoms. Only a mild amount of polishing was required and on evaluation of the microscopic chip at one end of the fragment it was decided not to build up as it was looking very natural. The patient has now been recalled after one month and then after another six months.

Clinical Considerations

This particular case is a classically ideal case for fragment reattachment. The fragment was broken and found intact. It broke just about leaving the pulp chamber without any damage. Literally speaking the pulp was saved by the skin of the teeth. The tooth in question was of a proper shape and size and allowed the fragment to be reattached very comfortably. In case the basic tooth itself is malpositions, misshapen or of an improper color it may make better sense to build it up with a veneer or a crown rather than recreate the old anatomy which is not aesthetic.

Another aspect to be considered is the time frame within which the therapy is carried out. The faster the reattachment done the better is the prognosis. This case, was once again favorable since the patient was on the dental chair within 35 minutes of the trauma. In case the fragment gets too dehydrated the bonding may not be good enough.

In case the time frame is not good it may still be a good idea to bond the fragment back and then possibly veneer the tooth. There are a number of studies which show that the final strength of the tooth when veneered after bonding the fragment back tends to be more than that of a veneer placed on a broken tooth. Hence it may just benefit the patient to have the fragment bonded back even if a veneer or a crown is being placed ultimately. A reattached fragment can afford the clinician the luxury of placing a veneer on the tooth instead of a full coverage crown which conserved tooth structure. The veneer can then serve the purpose of providing aesthetics as well as function and the end result is a much stronger tooth.

Andreasen in a clinical study on monkeys concluded that pulp tissue generally responded well and remained undamaged after fragment fractures, irrespective of the future outcome of the attached fragment. In the absence of direct exposure, reparative dentine is a frequent feature of the pulp's response to crown fracture and restoration with composite or reattachment of the crown fragment with dentine bonding. These restorative procedures appear to ensure continued function of the underlying pulp.

Even though this particular case did not warrant any endodontic intervention and root support reinforcement, at times it may be necessary to carry out endodontic therapy and actually fabricate a post and then subsequently create space in the fragment for the post and then bond it back to the tooth. If in doubt, it is best to just carry out a direct pulp capping as done in this case. Endodontic therapy can always be carried out even after bonding the fragment back in place without any compromise on the bond strengths.

The color of the fragment was marginally off the original tooth, immediately after bonding. This was due to the dehydration which takes place. The fragment with rehydrate once it is placed in the oral cavity. The shorter the time span between the trauma and treatment the lesser s the dehydration and the faster the fragment will regain its original color, translucency and hue. As was in this case, on Day three the fragment was barely distinguishable from the original tooth. In case the color does not match and the crack line is visible, a direct bonding procedure can rectify the situation.

Conclusions:

We can conclude from this case that the immediate fragment reattachment procedure which was carried out was beneficial in all respects. From the follow up it seems that the fragment is very well attached and hopefully will last for a long time to come. The traumatic injury to the tooth is the unpredictable component. It is very difficult to ascertain at this point of time if the case will go in for Endodontic therapy or not. There are absolutely no clinical indicators of any pulp pathology at the current moment nor does the radiograph show any such signs. In case of a pulp involvement at a latter stage, Root canal therapy will be have to be initiated and should not be much of a problem.

The very microscopic near pulp exposure should not be a cause for concern as a very adequate seal was achieved and the exposure was handled immediately with all due methodologies. In the authors opinion, much more extensive exposures have worked very successfully with current techniques.

The other uncharted waters are the ability of the bonded fragment to last over a period of years. Even though a few lab studies and material bond strengths of today the hypothesis says that the procedure should work for a long period. Only time will tell if the hypothesis matches up to reality.

In summation the immediate procedure will only prove beneficial to the patient even if a subsequent veneer or a crown is required. At the current moment the clinical situation has been restored to perfect health with just a 45 minutes chair side procedure.

References:

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