Full mouth rehabilitation cases are one of the most difficult cases to manage. They involve not only replacement of the lost tooth structure but also restoring the lost vertical dimensions. Dr.Mona Kakar presents this case of full mouth rehabilitation done with completely metal free technology.

Full Mouth Rehabilitation - Another Success Story

Patients generally present with isolated problems in individual teeth, or in isolated teeth in different locations in the oral cavity. Very rarely patients will present with total wear and tear of all teeth but still have all the teeth in the oral cavity. One such case seen at Sanjeevni Dental Clinic presented with all the 28 teeth intact, but with attrition and erosion of all the teeth.

The patient is a 45 year old man with no obvious habits which should lead to such extensive destruction. A detailed history and examination revealed that the patient had a habit of bruxing in the day as well as while sleeping. The attrition was marginally less in the posteriors as compared to the anterior teeth. There was a total collapse of the vertical dimension. The lower anterior teeth were totally razed to the gingival level. The upper lateral incisors and canines were also very badly destroyed.

The patient was very keen on saving all the teeth and was prepared to undergo any amount of extensive treatment to achieve the end result. He had been presented with a couple of other treatment options. One of the options was to remove all the teeth and prepare a full denture for both the arches. This was the preferred mode of treatment offered to the patient. His extreme reluctance to get the teeth extracted got him the option of possibly saving a few of the posterior teeth and extracting all the other teeth and making a removable partial denture. The patient was not too sure of this treatment plan either.

Clinical Findings

. A thorough and complete examination of the oral cavity was carried out for the patient. The examination revealed the following:

• The second molars were the only teeth in any form of intercuspating occlusion.
• The first molars showed more than 40% attrition on the occlusal surfaces and there was no intercuspation of any sort.
• The upper right lateral incisor and canine were attrited to the gingival level.
• The lower anteriors from the right first premolar to left canine were totally razed to gingival level.
• All the remaining teeth presented with more than 40% of loss of crown structure.
• The patient was unable to reproduce any stable centric occlusion.
• Lateral and protrusive excursions were not guided correctly by any group of teeth.
• There was a total loss of vertical dimension (approximately 5 mm at the central incisor level)
• The periodontal condition was very good. There were no signs whatsoever, of any inflammation or disease process
• There were very few incipient or advanced carious lesions seen in the existing teeth. The loss of tooth structure was clearly attributed to the patient's habit of bruxing.
• A total of nine teeth showed pulp exposures due to the excessive loss of tooth structure in spite of the secondary dentin formation. Seven mandibular teeth and two maxillary teeth had pulp involvements.

After a detailed clinical examination it was decided that the first and foremost treatment modality to be done was to treat the root canals of all the teeth which had pulp exposures. The involved teeth were all the lower teeth from right first premolar to left canine. The upper right lateral incisor and canine were also proposed for Root canal therapy. It was also planned to ultimately place posts in all these nine teeth since the coronal structures of all these teeth were totally destroyed.

The detailed examination also showed that all teeth from second molar to second molar had a minimum of 40% of coronal tooth loss. This necessitated full occlusal coverage restorations for all the teeth. The critical issue was not that of just providing the full coverage, but also to reestablish the vertical dimension of the jaws. The vertical dimension had to be reestablished, while at the same time balancing the occlusion on both the sides. This was going to be the most difficult aspect of treating the case - to provide proper intercuspation, a balanced occlusion and to simultaneously establish a comfortable vertical dimension for the patient.

The second phase planned was to provide full crowns/onlays on the posterior teeth, from first premolar to second molar. It was decided to initially restore the right side. It was decided to place the upper and lower teeth simultaneously to be able to establish a proper occlusion.

The next step planned was to immediately restore the other side by placing the other eight crowns/onlays, using the restored right side as a reference guideline. After posterior rehabilitation of both sides, the patient would be given about 2 weeks to adjust to the new occlusion and the newly established vertical dimension. After this waiting period, the four canine teeth were to be built up. Posts and cores and crowns were needed on the upper right canine and lower canines, and a direct build up of the incisal edge was needed in the upper left canine. There was enough ferrule available in all the canines to avoid a crown lengthening procedure. The next set of teeth to be tackled would be the upper incisors, out of which the right lateral incisor was to receive a fiberglass post and composite core, and then subsequently, a crown. A CLP procedure was to be undertaken on the two central incisors and the right lateral incisor prior to that. The remaining three incisors were to be directly built up in the mouth with light cured composite material.

Since all the four lower incisors were completely attrited to gingival level, it was decided to carry out a CLP procedure on these teeth. After the completion of the CLP healing phase, all the four teeth would be built up with fibreglass posts & composite cores, and crown preparations done on all the teeth. Subsequently, full crowns would be placed on all the teeth.

It was decided that the material to be used for the entire prosthetic work would be the Sculpture/Fibrekor material from Pentron Inc. Sculpture is a highly resilient polyceramic material, which allows great flexibility during working. It was also decided that the fabrication of the posterior crowns as well as the establishment of the vertical dimension would be done by the clinician and not sent to a laboratory.

The ability to be able to add and reduce at will with the Sculpture crowns, would make it possible to be able to adjust the crowns and get to a vertical dimension by taking trials chair side in the patients mouth itself. The occlusion and intercuspation was to be checked and modified chair side. This eliminated the need to do a bite transfer as well as the need to mount the cast on an articulator. The idea was to create a perfect anatomy on the lower teeth and then establish the upper anatomy and intercuspation with reference to the fixed lower teeth. The most critical part would be to establish the exact vertical dimension.

Step by Step Procedure

To start with, the entire treatment plan was explained to the patient and he was made aware of all the pros and cons of the suggested treatment plan. Once the patient was explained all aspects, pre-operative intra oral photographs were taken. Then preliminary upper and lower alginate impressions were made to fabricate study model casts.

The study model casts were then analyzed and then it was decided that one posterior set of teeth would be fabricated first to establish the vertical dimension and subsequently the other side would be created using the existing rehabilitated teeth as a frame of reference.

The lower right first premolar was fitted with a glass fibre post and a composite core build up. Full crown/onlay preparations were done on the lower right first molar and premolars and the upper right first molar and premolars. No occlusal reduction was undertaken for any of the teeth being prepared. Polyvinyl siloxane impressions were made of the upper and lower arches. Full crowns/onlays were fabricated with Sculpture for all the six teeth. The vertical height was increased by 3 mm at the second premolar, which was the calculated minimal loss of vertical dimension. No temporaries were prepared. The crowns were fabricated within 3 days of tooth preparation.

The mandibular crowns/onlays were then tried out and once the fit and margins were checked and passed, the crowns were bonded with a dual curing resin based luting agent. After the mandibular restorations were bonded into place, the maxillary teeth were placed and the fit and margins evaluated. Once the fit and margins were checked and passed, the occlusion and intercuspation was checked. The occlusion was checked in centric position and then checked in protrusive and lateral movements. The patient's comfort levels were also checked and the ability of the patient to intercuspate repeatedly at the same centric position, was evaluated. All necessary occlusal adjustments were carried out by direct reduction or addition of material from or to the restoration as required. Once the patient was totally comfortable and the clinician thoroughly satisfied the maxillary crowns were then bonded into place with a resin based dual curing luting agent.

The entire process of trials, modifications & bonding of the upper and lower six crowns/onlays on the right side took three clinical and three non-clinical days. Subsequently, the patient was told to report back after five days, which was the time for acclimatizing to the new prostheses and vertical dimension. He was instructed to take soft diet and start using the right side immediately. After a week the patient reported back and was totally comfortable. The patient had settled very well into the new vertical height and was eating very well with the new occlusion. Once the comfort levels were ascertained, the next step was initiated. It was noted that the second molars on the right side would also need restorations as the increase in vertical dimension necessitated it. It was originally thought that the second molars may not need inclusion in the restoration list due to the hinge effect retaining the intercuspation amongst the second molars.

The left side crown/onlay preparations were done for four lower teeth this time, as the second molars were included. Both the molars and premolars in the mandible were prepared and a polyvinyl siloxane impression made. The difference in this step was that now, the right side had a stable occlusion and the vertical height had been established. Hence, the fabrication of the crowns/onlays for the left side was done in accordance with the parameters established by the right side. Once the laboratory fabrication was completed, the mandibular restorations were tried out. The fit and margins of all the individual crowns/onlays were checked and passed. The restorations were then bonded with resin based dual curing cement. The maxillary premolars and molars were then prepared and a polyvinyl siloxane impression made. At this stage, a wax bite registration of the left side helped to articulate the models perfectly and facilitate the creation of the crowns/onlays. These creations were then individually tried for margin integrity and fit, and passed.

Next, the intercuspation was checked and the necessary adjustments carried out till a perfect harmony was achieved between the right and left sides. The patient's comfort levels were ascertained and then the four upper crowns/onlays were bonded into place. After bonding, the occlusion was again checked for bilateral stability. The protrusive and lateral movements were then tried out and any isolated interferences were removed. The patient at this point of time was already quite comfortable with the right side posterior segment.

The remaining two teeth of the posterior segment were then prepared for onlays and impressions made. The intercuspation already well established, it was a routine onlay fabrication and fitting process carried out for both of these remaining teeth. Needless to say, the occlusion was checked meticulously prior to as well as after bonding the restorations in. Once it was confirmed that the entire posterior dentition was stable, the patient was told to now masticate with all the posterior teeth and report back after two weeks.

The patient reported back after two weeks and was very comfortable with the occlusion and reported that he had absolutely no discomfort in chewing food or during any other time. Upon checking, no abnormal movements and sounds were detected in the TMJ region. The next phase of treatment was then undertaken: to start restoring the upper and lower anterior teeth. Root canal therapy had already been completed for all the lower 6 teeth as well as the right maxillary lateral incisor and canine teeth. The next step was to rehabilitate the four canines.

Glass fibre posts were bonded in the canals of both the mandibular canines and the maxillary right canine. These three canines were then prepared for full crowns and impressions made in polyvinyl siloxane for the same. The three canine crowns were then fabricated and tried out in the mouth. The canines were fabricated to allow for the lower canine crowns to be able to create canine guided protrusive and lateral movements with the relevant disclusions. The maxillary left canine was not sufficiently destroyed to warrant a full crown placement. Current restorative composite materials were decided upon for the restoration of the minimal tooth structure loss of this tooth. Thus, prior to the direct build up of the upper left canine, sufficient tooth structure existed to gauge the canine guidance. The gingival level attrition of the lower incisors facilitated viewing of and establishment of the canine guidance planes, providing a viewing "window". The adjusted crowns were bonded into place. The maxillary left canine was build up incisally and the labial erosion present was masked and contoured with directly placed light cured hybrid composite.

Soon after the canines were in place, the upper central and left lateral incisors were subjected to a CLP procedure to expose more of the clinical hidden crowns and therefore, to lend an element of height to the squat looking teeth. The maxillary right lateral incisor was built up with a bonded glass fibre post and composite core. The tooth was prepared to receive a full crown and the requisite impression made. The crown was fabricated, tried and adjusted for fit, marginal integrity and subsequently bonded with dual curing resin cement. Immediately following this, the maxillary central incisors and the maxillary left lateral incisor were built up at their incisal edges with directly placed light cured hybrid composite. All the direct restorations were meticulously polished.

The maxillary arch was now completely rehabilitated. Turning attentions to the mandibular arch, a CLP procedure was carried out for the lower incisor teeth to obtain sufficient crown length to establish a ferrule for the posts/cores. The CLP involved raising the soft tissue flap and reduction of marginal bone. The flap was sutured back and allowed to heal for a period of one week.

Then, glass fibre posts (FibreKor form Pentron Corp) were placed in all the mandibular incisors and a core build up was done with Build It core material (Pentron Corp). Full crown preparations were completed for all the four teeth and a poly vinyl siloxane impression made for the lower teeth. Then the lower crowns were fabricated and the patient called for trials. The crowns were adjusted for occlusion. The vertical dimension had already been established. The centric lock obtained from the training of the patient and from the creation of a stable intercuspation at that established position, allowed the lower incisors to be placed in their rightful Class I relationship with the upper teeth, even though the posterior teeth are tending towards a Class II relationship. The crowns were fabricated to be in harmony with the pre-established vertical height. Once again, after ascertaining the patients comfort levels, the crowns were bonded into place using a resin based dual curing luting agent. (Calibra - Dentsply).

This completed all the restorations. Fresh alginate impressions were now made and a vinyl bite guard was then fabricated for the patient to wear in the night since he has a history of heavy bruxism. The patient was explained the importance of wearing the bite guard and also maintaining the rehabilitated teeth.

Discussion

The major concern when attempting a full mouth rehabilitation with restoration of the vertical dimension, is the transfer of the condylar movement onto an articulator. This is very necessary to enable the laboratory fabrication of the prosthesis with appropriate intercuspation as well as the exact vertical height, which will allow the temporomandibular joint to function with stability & good health

Such transfer and replication of the mandibular movements requires complex materials, equipment and techniques. The entire gamut of activities for face bow transfers, condylar movement tracings and mounting on Hanau based articulators is totally eliminated since the articulation, vertical dimension, intercuspation and occlusal movements are adjusted and checked in the patient's mouth itself. The adjustments are done chair side and rechecked immediately. Any necessary additions and reductions are done instantly and the desired occlusion obtained.

Conclusion

Using the extremely flexible nature of the Fibrekor/Sculpture material it was possible to restore not only the lost vertical dimension of the patient, but from the entire mouth, 24 teeth were restored with crowns/onlays alone or crowns/onlays and posts. It was possible to adjust the occlusion as well achieve the desired intercuspation by repeated addition/reduction of the material. This material flexibility played the most critical role towards obtaining the excellent end result.