People in our society can expect to live longer than in any previous generation. Many choose to avoid loosing their teeth and refuse to use removable dental prostheses. They present with increasingly complex dental histories. For these reasons, dentists in the mainstream of dental care are increasingly practicing the skills of interdisciplinary treatment planning in order to restore patient’s dental health predictably and for the long term.
This paper will demonstrate a case of complex treatment planning to manage extensive tooth loss, inadequate restorative space and patient’s demand to avoid removable dental prostheses. In addition to missing posterior teeth, there was loss of the enamel on the incisors and therefore there was inadequate vertical space for dental restoration. In this case factors which caused the dental wear included missing posterior teeth, loss of vertical posterior support and enamel abrasion and erosion.
Interdisciplinary treatment to provide adequate room for dental restoration could include:
• Periodontal surgery to apically reposition the soft and hard tissue (crown lengthening) and provide adequate tooth structure for retention of the restoration,
• Orthognathic surgery to intrude segments of the dental arch to create space for restorative materials without the need to decrease the crown to root ratio.
• Orthodontic anterior intrusion or relative posterior extrusion to create space for restorative materials between the worn teeth,
• Restorative procedures to achieve anterior restorative space by increasing the vertical dimension (raise the bite).
The order of this list is from lowest to highest risk of restorative instability and therefore predictability. Often the optimum course of treatment is a combination of therapies designed to mitigate the risks of the therapies selected.
The co-ordination of the specialty treatment is the responsibility of the restoring dentist. In this case, the periodontal crown lengthening, provisionalization during the trial phase of the restoration, and the implant placement, timing and location was co-ordinated by the restorative dentist. It is always planned from the inception of the treat ment plan beginning with the end result in mind.
DIAGNOSIS AND TREATMENT PLANNING
The patient, L. M. aged 65 years, attended the clinic with 12 teeth missing and a chief concern A functional analysis was performed and there were no signs of pathology or symptoms involving the joints or muscles. There was a normal range of motion. Bilateral manipulation technique was used to record centric relation as defined by about loosing more teeth. He felt his teeth should look better and was self-conscious about his appearance.
Necessary radiographs, mounted study models and photographs were prepared (Figs. 1-10). Dawson. 1 A single initial point of contact on right bicuspids was identified as a dental interference to closure into centric relation. Early identification of occlusal interferences is important in the diagnosis and treatment planning of any comprehensive dental treatment.
The periodontal examination was revealed good periodontal health except for moderate pocket depth and bone loss involving the maxillary posterior teeth. There was favourable crown to root ratio of the remaining teeth and a thick soft tissue biotype was identified. The patient was in excellent health and a non smoker. A discussion about diet and the possibility of gastric ref lux disease as a contributing factor in the wear of the dentition did not reveal any specific causative factors.
The findings of the examination were presented to the patient in a co-diagnosis format during which the patient participated fully in the treatment decisions. Once the course of treatment was finalized, new mounted study models were prepared. The centric occlusal interferences were adjusted in the mouth. To improve the accuracy of the articulation of the models a custom bite rim was used. The vertical dimension was recorded at the proposed working dimension and transferred to the models with a rigid bite registration material. Prior to taking the maxillary impression, light cured composite material was sculpted onto the incisors to evaluate the effect on aesthetics and function of lengthening these teeth and closing the diastema.
A CT Scan confirmed adequate osseous dimensions in the mandible for wide implants posterior of the foramen and lingual of mandibular canal but inadequate bone in the right maxillary areas (first bicuspid and first molar positions) for the proposed implants.
TREATMENT SEQUENCING
Planning the timing of treatment from the outset was critical to the patients’ acceptance of the plan. The treatment was planned in four phases.
1. Preparatory bone grafting, implant surgery and periodontal surgery
2. Provisionalization of remaining natural teeth at the proposed vertical dimension
3. Restoration of anterior teeth
4. Restoration of posterior teeth
Phase 1
The bone grafting and implant integration would be the most lengthy phase of treatment and it was initiated first. A prosthetic waxup (Figs. 11, 12) was used to create surgical stents for the implant placement. Bone grafting for the upper right first bicuspid and molar regions was accomplished at the same time as mandibular implant placement. AstraTech (AstraZeneca, Waltham, MA) implants were used in all eight surgical sites. One of the implants in the mandibular posterior was removed within weeks of initial placement and was replaced after two months healing. Healing of the graft in the maxilla, placement of the maxillary implants and subsequent osseointegration would require a minimum of 7-9 months. bite raising procedures. 2 The risk is mitigated by provisionally restoring the teeth at the proposed vertical dimension for a minimum of six months before the definitive restoration. A waxup at the proposed vertical dimension is required for this purpose (Figs. 13-14) in order that preparation guides, and laboratory
Crown lengthening surgical repositioning of soft tissue and osseous recontouring in the maxillary anterior region was performed to achieve adequate tooth mass for restorative procedures. Maturation of the periodontal surgery sites required at least three months and proceeded at the same as the implant integration.
Phase 2
It is important to anticipate the likelihood of relapse of restorative provisionals can be prepared.
Following the initial healing of the periodontal surgery and during implant integration (Fig. 15) the remaining teeth which were to be restored were treated with caries removal, endodontic therapy, foundational restorations, and acrylic laboratory processed provisional restorations. The lower incisor teeth were splinted with bonded composite restorative material. The acrylic labo- ratory fabricated crowns were cemented with eugenol containing temporary cement (Fig. 16).
The provisionalization period is an opportunity to confirm the stability of the new vertical dimension and for the patient and their family to assess and approve the newly lengthened teeth. Also, the patient can experience the new bite relationship and necessary adjustments to achieve a adequate occlusal scheme can be performed. The provisionals are checked for comfort, adequacy of fit and retention at least monthly.
Phase 3
Twelve months after provisionalization the implants were integrated and healing abutments were in place in all areas. In a single appointment, using conscious sedation protocols, all anterior teeth and bicuspids were prepared according to the Biomimetic principals demonstrated by Magne and Belser3 to receive the definitive restoration and the long term provisional restorations were either replaced or relined as needed. Two weeks later the definitive anterio
r and bicuspid restorations (porcelain fused to metal crowns and porcelain bonded restorations) were cemented and bonded.
Phase 4
Soon after the anterior and bicuspid restorations were placed, the posterior teeth (maxillary first molars and mandibular implants) were prepared to receive their definitive restorations. Impressions and mounting records were provided to the laboratory to prepare working models (Figs. 17-18) and two weeks later, the definitive posterior restorations were inserted and cemented.
There is a large body of evidence which promotes the advantages of screw retained implant restorations4 and wherever possible in this case the restorations were screw retained rather than cemented. Because all porcelain occlusion was preferred in this case, low fusing porcelain was used to minimize the trauma possible in all porcelain occlusions. 5
The occlusal scheme, which had been planned from the beginning of treatment with the initial waxup was refined, including:
• Mutually protective occlusion
• Flat but immediate cuspid disclusion of posterior segments
• Protrusive disclusion on at least two teeth at all times
• Light initial centric contact on natural teeth only followed by centric contact on implants only with heavier occlusal force. 5
The final restorations, at two-year recall, are presented in Figures 19-26.
CONCLUSIONS
This case demonstrates the importance of sequencing complex restorative treatment and creating a restorative treatment plan with the goal of the final restoration in mind. Restoring dentists must “quarterback” the treatment plan and be responsible for understanding the potentials of interdisciplinary procedures and their limitations. The dentist must then co-ordinate the specialty treatments for a predictable prosthetic solution to the patients’ restorative requirements. oh
Dr. Kleeberger is a GP in Langley, BC. He is an alumnus of the Millennium Institute in Calgary and of PAC~Live programs at UOP in San Francisco. He can be reached atdrkleeberger@telus.net.The author mentors the Fraser Valley Dental Fundamentals Study Club, which is, in part, supported by Dentsply Canada.
Oral Health welcomes this original article.
References
1. Dawson, P. E. Functional Occlusion From TMJ to Smile Design St. Louis, MO: Mosby Esvier: 2007.
2. Spear, F. Occlusion in Clinical Practice. Seattle Institute for Advanced Dental Education, Seattle, WA, 2003.
3. Magne, P., Belser, U. Bonded Porcelain Restorations, A Biomimetic Approach. Quintessence Pub: 2002.
4. Michaelakis, K. X., Hirayama, H., Garefis, P. D. Cementretained versus screw-retained implant restorations: a critical review. Int. J. Oral Maxillofacial Implants 2003 18:5.
5. Misch, C. E. Dental Implant Prosthetics St. Louis, MO: Mosby Esvier: 2005.
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ABSTRACT
A case study of a complex restoration involving interdisciplinary treatment planning to achieve adequate vertical restorative space, restore worn dentition and replace missing teeth is presented. An orderly progression of treatment planning and delivery, rationales for selection courses of therapies from those available and issues encountered during the course of treatment are discussed.
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Dentists are increasingly practicing interdisciplinary treatment planning in order to restore dental health
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Bilateral manipulation technique was used to record centric relation as defined by Dawson
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To improve the accuracy of the articulation of the models a custom bite rim was used
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One of the implants in the mandibular posterior was removed within weeks of initial placement and was replaced after two months healing
