A Multidisciplinary Approach to Rehabilitate Function and Esthetics

An otherwise healthy, middle-aged man presented to discuss what options he had to address the health, appearance, and diminishing function of his teeth. Access to dental care had been available to him throughout his life, and he had undergone many restorations, extractions, and root canal treatments. He was not experiencing any pain or taking medications for any chronic illnesses, and he was open to any suggestions regarding treatment to address his dental concerns (Figure 1).

A comprehensive dental examination was performed, and no temporomandibular joint dysfunction or parafunction of concern was revealed that could potentially affect the longevity of any planned restorations. The upper anterior teeth exhibited excessive wear, which was due to crowding of the lower anterior teeth. This was one of the things that the patient wanted to address. The patient also presented with a narrow upper arch and a high palatal vault, but he declined treatment to address the skeletal discrepancies of his maxilla and mandible because it was not a priority for him. For situations in which the correction of overjets, overbites, or skeletal relationships is involved, a general dentist should always offer a referral to an orthodontic specialist as an option because this treatment falls outside of the scope of a general dentistry practice. However, if these patients only want to realign their teeth in order to improve their smiles, offering them short-term orthodontic treatment is an option. The options that were offered in this case included removable clear aligners, removable active orthodontic appliances (slow mandibular and maxillary expansion devices), fixed orthodontic treatment, or a combination of these modalities. The patient agreed to short-term fixed orthodontics in order to improve the alignment of his lower anterior teeth from premolar to premolar.

A panoramic radiograph revealed a vertical root fracture on tooth No. 12 and an apical radiolucency associated with tooth No. 30, which was nonvital (Figure 2). The absence of teeth Nos. 19 and 29 bothered the patient, and implants were discussed as an option to replace them. The patient was told that in order to replace tooth No. 31, tooth No. 32 would have to be extracted due to its mesioangular position, but he was not concerned about replacing tooth No. 31.

To address the nonvital tooth No. 30, root canal treatment was discussed; however, the patient preferred removing it and replacing it with a dental implant. He had already had a few root canal treatments in the past and felt that because this particular tooth exhibited structural issues for many years, it was not worth the risk to spend more time and money trying to save it. A study on implant survival rates conducted by Buser and colleagues¹ demonstrated that the cumulative 5-year success rate of dental implants in partially dentate patients with augmented bone was 98.6%.

Different options for restoring the upper anterior teeth were discussed with the patient. One included orthodontic movement of the upper teeth, followed by the utilization of techniques that involve minimal or no preparation of the tooth structure to facilitate superficial additive restorations with composite resin. An alternative, more invasive option would involve preparing the teeth for full porcelain laminate veneers, which would simultaneously improve the alignment and smile line as well as permit the removal of old, existing restorations. The patient decided on the second option because he had to travel a considerable distance to get to the practice and felt that the first option would add too much additional treatment time.

With the exception of the lower anterior teeth displaying isolated plaque-induced gingival inflammation and subgingival calculus, the patient's oral hygiene was average. He reported that due to the crowding among his lower anterior teeth, he had always struggled with cleaning them and maintaining low plaque levels, which was consistent with the intraoral hygiene findings.

Clinical Treatment

For the anticipated 6 months of short-term fixed orthodontic treatment in the lower anterior, the decision was made to keep tooth No. 30 in order for it to act as an anchor, along with tooth No. 18, for molar tubes (First and Second Molar Tubes [0.022 in  0.028 in], TP Orthodontics, Inc.) to assist during orthodontics (Figure 3). Ceramic brackets with a slot size of 0.022 in (InVu^® Cosmetic Readi-Base^® Brackets With eXact^® Pre-Applied Adhesive, TP Orthodontics, Inc.) were placed on teeth Nos. 20 through 28 (Figure 4).² Throughout the duration of the treatment, different archwire types and sizes were utilized, including an esthetic nickel-titanium archwire (Reflex^® Nickel Titanium [0.014 in], TP Orthodontics, Inc.) and an esthetic stainless steel wire (Shiny Bright Stainless Steel [0.016 in x 0.022 in], TP Orthodontics, Inc.), depending on the type of movement that was required to move the teeth into their planned final positions. Due to nickel-titanium archwire's adaptability, high resilience, and production of a reduced but constant force, its use was an excellent choice to commence treatment in this case.³

Once the lower anterior teeth were aligned and in more favorable positions, the archwire, brackets, and molar tubes were removed. A removable clear retainer (Essix^® Plastic, Dentsply Sirona) was fabricated and delivered to the patient to ensure the retention of teeth Nos. 20 through 28 while treatment progressed to the surgical phase.⁴ This phase involved the extraction of teeth Nos. 12 and 30 and the subsequent placement of four tapered dental implants (Tapered Plus, BioHorizons) in the positions of teeth Nos. 12, 19, 29, and 30. Simultaneous with implant placement at all four of these sites, guided bone regeneration procedures were performed using biocompatible porous bone mineral substitute (Geistlich Bio-Oss^®, Geistlich Pharma North America Inc.) and collagen membrane (Geistlich Bio-Gide^®, Geistlich Pharma North America Inc.), then subepithelial connective tissue grafts were placed, which were harvested from the patient's maxillary tuberosity and palate.^5,6 For each implant that was placed, good primary stability was achieved in type II bone with adequate horizontal and vertical dimensions and insertion torque values greater than 40 Ncm, providing confidence that secondary stability would be likely. Healing abutments were placed at this visit. No temporary restorations were utilized during the healing phase because it would have been difficult to control potentially harmful micromotions that can negatively influence osseointegration and bone remodeling by forming fibrous tissue and inducing bone resorption at the bone-to-implant interface (Figure 5).⁷

After 4 months of healing, which allowed the bone to remodel around the implants and the soft tissue to stabilize, the patient returned to the office to have his four upper anterior teeth prepared for porcelain laminate veneers. In addition to repairing the damage from wear, the veneers would improve the patient's current negative smile line and give his smile a flatter and wider appearance. Although he was not immediately interested in tooth whitening treatment, he wanted the veneers to be at least one shade lighter than his existing natural tooth shade. A failing amalgam restoration on tooth No. 20 with associated fracture lines prompted the decision to prepare the tooth for a full-coverage porcelain crown and simultaneously take open tray impressions for the four implant-retained crowns.

Due to lithium disilicate's excellent optical properties, high mechanical resistance with a flexural strength of 350 MPa to 450 MPa, restorative versatility, and ability to achieve a high-strength bond, it was the material of choice (IPS e.max^®, Ivoclar Vivadent) for the porcelain veneers on teeth Nos. 7 through 10 and the full-coverage crown on tooth No. 20.⁸ It is a highly translucent glass ceramic with optical properties resulting from the optical compatibility between the glassy matrix and the crystalline phase, which minimizes the internal scattering of the light as it passes through the material.⁹

For the implant restorations, the decision was made to use zirconia crowns (Prettau^®, Zirkonzahn)¹⁰ direct to custom zirconia abutments (Prettau, Zirkonzahn),¹¹ which were selected because of the biocompatibility, high compression and traction resistance similar to stainless steel, and low plaque accumulation potential of the yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) that are used in dentistry.¹² To reduce the possibility of cement-related complications and improve retrievability, the implant crowns were screw retained (Figure 6).¹³ After all of the ceramic restorations were placed, a new removable clear retainer was made that covered all of the teeth in the lower arch.

At a follow-up appointment 4 years after the completion of treatment, the patient demonstrated healthy and stable soft tissue around the implant-retained zirconia crowns as well as the other lithium disilicate restorations (Figure 7 through Figure 11). He expressed his satisfaction with the improved function of his teeth and the esthetics of his smile.

By regularly upskilling, general practitioners can acquire the necessary knowledge and skills to treat patients with a multidisciplinary approach and address most of their concerns within the comfort of one practice. The ability to provide continuity of care and treat patients from the planning phase all the way through to the maintenance phase provides many benefits, including that a clear vision for the treatment outcome is being controlled by only one clinician, which can potentially save patients precious time and money.

Hanno Venter, BDS
Master
International Congress of Oral Implantologists

Orange Moose Dental
Bundaberg, Australia