Systematic Approach to Full-Mouth Reconstruction

Ara Nazarian, DDS

0 Shares

INTRODUCTION
As the public becomes increasingly aware of available options for cosmetic dental reconstructions, the challenges dentists and their laboratory teams face when providing treatments that meet a patient’s multiple expectations also increase. These involve comprehensively identifying all of the patient’s dental problems and needs, as well as precisely determining the best restorative approach for the individual. Other challenges encompass planning, selecting materials and techniques that will achieve the desired outcomes, and streamlining the associated procedures for maximum patient comfort and team efficiency.

However, satisfying demands for restorations that achieve both aesthetic and functional rehabilitation is possible when team member collaboration is based on a systematic approach to treatment planning.1,2 Fortunately, a variety of diagnostic tools, clinical techniques and armamentaria, and material options are available to facilitate success in restoring a smile to proper form, function, and health. Among them are wax-up models and face-bow transfers, preparation reduction guides, customized impression trays, and strong aesthetic materials that can be efficiently CAD/CAM fabricated and seated with an integrated system of adhesives.2

Figure 1. Preoperative full-face view of a patient in his 50s who was dissatisfied with the appearance of his smile.

These components of a systematic approach are demonstrated in the following case presentation. In particular, tools and techniques for planning, tooth preparations, and selecting materials for a full-mouth reconstruction are illustrated in the context of their respective restorative treatment application.

CASE REPORT
Diagnosis and Treatment Planning

A male patient in his late 50s was referred by another dentist because he was dissatisfied with the appearance of his smile (Figure 1). The patient commented that his existing teeth and restorations were unattractive due to their size, shape, color, and wear (Figures 2 to 4). Most importantly, he indicated that he was suffering from tension headaches, grinding his teeth, and a limited range of function.

Figure 2. Pre-op close-up view of the smile. Figure 3. Pre-op retracted closed bite view.
Figure 4. Pre-op retracted view showing the patient’s opened bite.

Initial diagnostic evaluation at the first appointment consisted of a series of digital images with study casts, a centric relation bite record and face-bow transfer, and full-mouth radiographs.1,2 In the maxillary arch, the patient showed several teeth with worn composite restorations (Nos. 2, 6, 8, 11, 12, 14, and 15), as well as teeth PFM crowns (Nos. 3, 4, 9, and 13). Tooth No. 5 had a large amalgam restoration with a crack in the mesial marginal ridge (Figure 5). In the lower arch, several existing crown restorations showed wear and fractured porcelain (Nos. 19 to 21). There was also some evidence of wear on the composite restorations in teeth Nos. 18 and 28 to 31. Although no restorations were present in the anterior mandibular teeth, the incisal edges were severely worn due to possible grinding and parafunction (Figure 6).

After reviewing the clinical findings and mounted models, the patient was diagnosed with a restricted envelope of function and decreased vertical dimension from continuous wear.3 To develop a treatment plan and determine if the vertical dimension could be increased, a diagnostic 3-D white wax-up (Arrowhead Dental Lab) was fabricated (Figure 7). The vertical dimension of occlusion was increased by 1.6 mm in the wax-up. Based on information gathered during the initial consultation, it was determined that the maxillary central incisors could be lengthened by 1.3 mm to improve aesthetics. The canines would also be lengthened to restore canine guidance in lateral excursions.4 The goals for the mandibular anterior teeth were to correct the length-to-width ratio and to create a less worn appearance. Additionally, the diagnostic wax-up demonstrated that aesthetics and function could be enhanced by restoring all of the teeth.3,4 The final treatment plan consisted of removing any existing crown restorations, placing composite cores where needed, and placing new crown restorations from teeth Nos. 2 to 15 in the upper arch and teeth Nos. 18 to 31 in the lower arch.

Figure 5. Pre-op maxillary occlusal view revealing a large amalgam restoration with a crack in the mesial marginal ridge on tooth No. 5. Figure 6. Pre-op mandibular occlusal view showing severely worn incisal edges due to possible grinding and parafunction.
Figure 7. A diagnostic wax-up (Arrowhead Dental Laboratory) was used to develop a treatment plan and determine if the vertical dimension of occlusion could be increased. Figure 8. Preparations.

The material of choice for these restorations was milled lithium disilicate (IPS e.max CAD [Ivoclar Vivadent]). Manufactured through an innovative process, this machinable glass-ceramic is produced for laboratories in a crystalline intermediate phase. In this “soft” state, the material exhibits its unusual “bluish” color and strength of approximately 160 MPa. In this “blue” phase, restorations can be manually adjusted or cut back in a fast and efficient fashion. The material acquires its final strength (360 MPa) and desired aesthetic characteristics (ie, tooth color, translucency, brightness) during a simple and quick crystallization process.5-8

Tooth Preparation
Treatment was initiated after obtaining the patient’s informed consent.

Once anesthetic was administered, existing crown restorations were removed. If any old amalgam restorations were present, or if there was any indication of recurrent decay remaining, the teeth were cored with composite using a carbide bur (Midwest MultiPrep [DENTSPLY Caulk]). A universal adhesive bonding agent (Adhese Universal [Ivoclar Vivadent]) was applied according to the manufacturer’s protocol using its unique VivaPen (Ivoclar Vivadent) delivery system, and then light cured (Demi Ultra [Kerr]). Because this adhesive is compatible with all etching protocols and can be used for a variety of clinical procedures (eg, direct composite restorations; direct-placed core buildups with light-, self-, and dual-curing composites; and adhesive cementation of indirect restorations), it saved time during the build-up process. Buildups were then accomplished on teeth Nos. 3 to 5, 9, 13, and 19 using a core buildup composite (MultiCore Flow Light [Ivoclar Vivadent]) (Figure 8). To quickly, comfortably, and precisely prepare the teeth for optimal results, a clear reduction guide (Arrowhead Dental Laboratory) that was provided with the 3-D white wax-up was used to ensure adequate reduction for the definitive restorations (Figure 9).9,10

All teeth were prepared using a coarse grit chamfer diamond bur 856 (Axis|SybronEndo), beginning with teeth Nos. 4 to 13 and then teeth Nos. 20 to 29. After preparation, a sequential bite was obtained using a vinyl polysiloxane (VPS) bite registration material (Blu-Mousse VPS [Parkell]), and a stump shade (IPS Natural Die Material shade guide [Ivoclar Vivadent]) of the preparations was selected to assist the laboratory in creating natural-looking restorations. A viscous retraction paste (Expasyl [Kerr]) was used as an alternative to retraction cords to achieve gingival retraction and to control hemorrhaging (contains aluminum chloride). It was allowed to sit in the sulcus for 2 minutes, after which it was thoroughly rinsed off with copious amounts of water.

A full-arch impression was taken using a customizable crown and bridge tray (Instant Custom C&B Trays [Goodfit]) and heavy- and light-bodied VPS impression material (Take 1 Advanced [Kerr]). The proprietary polymethyl methacrylate tray material becomes adjustable when heated in boiling water (Figures 10 and 11), providing an efficient method for capturing a dimensionally accurate impression with uniform thickness of impression material.11,12 Full-arch impressions were taken after the trays were molded and customized to the patient’s arches and loaded with the impression materials (Figure 12).

Figure 9. A clear reduction guide (Arrowhead Dental Laboratory) ensured adequate reduction for the definitive restorations. Putty templates were used to create the provisionals. Figure 10. The customizable polymethyl methacrylate impression tray (Instant Custom C&B Trays [Goodfit]) was warmed in water to facilitate easy manipulation.
Figure 11. The custom trays were then shaped to accommodate the patient’s
arches.
Figure 12. The impression material (Take 1 Advanced [Kerr]) was loaded into the custom impression trays.

A bite-relation jig, which was fabricated on the 3-D white wax-up models, was tried in the mouth and removed. Next, the light-body impression material was placed into the bite-relation jig and seated onto the preparations. The patient was told to close into the bite-relation jig until he reached vertical stops. Then the material was allowed to set with the patient biting gently on the vertical stop. Details of the anticipated final restoration size, shape, and color, as well as the 3-D white wax-up models, were forwarded to the dental laboratory team.1,2

Provisionalization
Using a VPS putty mold (Sil-Tech [Ivoclar Vivadent]) of the wax-up, provisional restorations were made in shade B1 of a temporary material (Structur 3 [VOCO America]) to assess the ideal size, shape, color, and position of the definitive restorations. The provisional material was loaded into the provisional stint (Figure 13) and then seated on the preparations. The provisionals were fabricated within minutes (Figure 14) and trimmed with trimming burs and discs (Axis|SybronEndo). The teeth were desensitized (Telio CS Desensitizer [Ivoclar Vivadent]) and dried, and the provisionals were temporarily cemented (Temp-Bond Clear [Kerr]).

The patient returned a few weeks later for evaluation of aesthetics, phonetics, and occlusal function. Already exhibiting excitement and confidence with his provisional restorations, he indicated that all of his co-workers noticed that he seemed to look younger and happier. Most importantly, he was no longer experiencing discomfort in the temporomandibular joint and stated that his bite never felt better. Because no adjustments or modifications to the provisionals were necessary, the dental laboratory team was instructed to replicate the 3-D white wax-up in the definitive restorations.

Laboratory Considerations
The wax-ups, color photographs, impressions, and bite relations were forwarded to the dental laboratory team. Due to the significant color variation among the preparations, a light translucency lithium disilicate block (IPS e.max CAD) for full-contour restorations was selected. With lower translucency, these blocks were ideal for masking color discrepancies due to tooth discoloration or underlying posts or cores. When a cutback and subsequent layering porcelain (IPS e.max Ceram [Ivoclar Vivadent]) and technique are used, enhanced aesthetics for the anterior teeth can be achieved. However, monolithic lithium disilicate can be used in these cases in the posterior to maintain increased strength.

Cementation
After 3 weeks, the patient returned for placement of the definitive restorations. Following the administration of a local anesthetic, the provisional restorations were removed using an Easy Pneumatic crown and bridge remover (Dent Corp). Any remaining temporary cement was removed, and the preparations were cleaned with chlorhexidine 2% (Consepsis [Ultradent Products]). The final lithium disilicate CAD/CAM restorations (IPS e.max CAD) were tried in to verify marginal fit, contour, and accuracy. The patient examined the appearance of these restorations in a mirror and, once satisfied, approved them for final cementation.

Figure 13. Full-arch provisionals were created. Figure 14. View of the completed maxillary provisional restoration.
Figure 15. Resin cement (Variolink Esthetic DC [Ivoclar Vivadent]) was loaded into the restorations. Figure 16. Post-op retracted closed bite view.
Figure 17. Post-op retracted open bite view. Figure 18. Post-op maxillary occlusal view: Ivoclar Vivadent’s IPS e.max CAD monolithic (posterior teeth) and layered (anterior teeth).
Figure 19. Post-op mandibular occlusal view. Figure 20. Post-op close-up view of the patient’s restored smile.
Figure 21. Postoperative photo of our happy, smiling patient.

The definitive restorations were removed and cleaned with a universal cleaning paste (Ivoclean [Ivoclar Vivadent]) by applying the paste to the internal surfaces of the restorations for 20 seconds, then thoroughly rinsing the paste off with water. This cleaning step enhances the bond strength between the indirect restoration and the resin cement. The preparations were then cleaned and dried with oil-free air, and a single-component, light-cured adhesive (Adhese Universal in the VivaPen dispenser) was applied. Care was taken to ensure that there was no adhesive pooling prior to the 10-second light-curing step (Demi Ultra).

The crowns were seated with a neutral shade of dual-curing adhesive resin cement (Variolink Esthetic DC [Ivoclar Vivadent]), beginning at the midline and working out distally to prevent canting (Figure 15).13 This cement was selected based on its shade stability, lifelike fluorescence, ease of cleanup, and increased radiopacity. In particular, the cement enabled precise shade matching of the restoration to surrounding dentition due to its “Effect” shade system, which encompasses 5 different shades for color-neutral cementation, yet provides brightening or darkening of the restoration as needed.

The restorations were secured until final polymerization was achieved. Due to the selected cement’s combination of light initiator and light sensitivity filter, easy cleanup of excess cement was possible following successful pre-polymerization with light. Using a T-Scan (Tekscan), the occlusion was verified to ensure that all proper contact points were ideally positioned, all done to maximize the longevity of the restorations (Figures 16 to 20).

IN SUMMARY
A systematic approach for treatment planning, material selection, tooth preparation, and cementation enables clinicians to address their patients’ needs more effectively and efficiently. Incorporating techniques and materials that facilitate greater control and accuracy throughout the restorative process also contributes to more predictable aesthetic and functional outcomes. In this case, the patient no longer experienced pain and was very pleased with his new enhanced “whiter” smile (Figure 21). Additionally, he commented on the effective and efficient manner with which the practice executed his treatment.

Acknowledgement
Special thanks from the author to Chris Barnes and his team at Arrowhead Dental Laboratory (Sandy, Utah) for fabricating the restorations depicted in this case.


References

  1. Cooper CC, Sosa AE. Full-mouth reconstruction: the importance of treatment planning in restoring aesthetics and function. Dent Today. 2012;31:92-95.
  2. Nazarian A. Utilizing an effective protocol for full-mouth reconstructions. Dent Today. 2014;33:100-103.
  3. Song MY, Park JM, Park EJ. Full mouth rehabilitation of the patient with severely worn dentition: a case report. J Adv Prosthodont. 2010;2:106-110.
  4. Abduo J, Lyons K. Clinical considerations for increasing occlusal vertical dimension: a review. Aust Dent J. 2012;57:2-10.
  5. Zhang Y, Lee JJ, Srikanth R, et al. Edge chipping and flexural resistance of monolithic ceramics. Dent Mater. 2013;29:1201-1208.
  6. Fasbinder DJ, Dennison JB, Heys D, et al. A clinical evaluation of chairside lithium disilicate CAD/CAM crowns: a two-year report. J Am Dent Assoc. 2010;141(suppl 2):10S-14S.
  7. Bindl A, Lüthy H, Mörmann WH. Strength and fracture pattern of monolithic CAD/CAM-generated posterior crowns. Dent Mater. 2006;22:29-36.
  8. Zimmermann R, Seitz S, Evans J, et al. CAD/CAM and lithium disilicate: an anterior esthetic case study. Tex Dent J. 2013;130:141-144.
  9. Oh WS, Saglik B, May KB. Tooth reduction guide using silicone registration material along with vacuum-formed thermoplastic matrix. J Prosthodont. 2010;19:81-83.
  10. Papaspyridakos P, Lal K. Use of vacuum-formed templates to guide tooth preparation and insertion of interim restorations. J Prosthodont. 2010;19:303-306.
  11. Shafa S, Zaree Z, Mosharraf R. The effects of custom tray material on the accuracy of master casts. J Contemp Dent Pract. 2008;9:49-56.
  12. Bomberg TJ, Hatch RA, Hoffman W Jr. Impression material thickness in stock and custom trays. J Prosthet Dent. 1985;54:170-172.
  13. Niu E, Agustin M, Douglas RD. Color match of machinable lithium disilicate ceramics: effects of cement color and thickness. J Prosthet Dent. 2014;111:42-50.

Dr. Nazarian maintains a private practice in Troy, Mich, with an emphasis on comprehensive and restorative care. A Diplomate in the International Congress of Oral Implantologists, his articles have been published in many of today’s popular dental publications. He is the director of the Reconstructive Dentistry Institute and has conducted lectures and hands-on workshops on aesthetic materials and dental implants throughout the United States, Europe, New Zealand, and Australia. He is also the creator of the DemoDent patient education model system. He can be reached at by calling (248) 457-0500 or visit the website located at aranazariandds.com.

Disclosure: Dr. Nazarian reports no disclosures.