Partial Rehabilitation of a Failing Geriatric Dentition
High-quality primer and resin cements deliver excellent bond strength for zirconia bridges and crowns
Joseph Kim, DDS
According to research, geriatric patients are keeping more of their teeth longer into their lives when compared with previous generations; however, the reasons for why this is happening are unclear.1 In 2017, overall edentulism among those in the noninstitutionalized US population who were at least 50 years or older was 11.4%.2
Nonetheless, it is not uncommon for older patients to present with a variety of dental restorations that reflect the decades of dental treatment that they have received from multiple dentists, all of whom possessed different philosophies and levels of skill. This can present challenges when considering how each existing restoration may fit into a comprehensive treatment plan.
Case Report
An 83-year-old male patient presented with the chief complaint that he could not chew his food properly. An evaluation revealed that he had failing crowns and had lost a bridge due to recurrent caries. Removable and fixed treatment options were discussed, and the patient elected to restore the remaining teeth with crowns and the missing teeth with implant-supported fixed partial dentures.
Treatment Planning
The patient had initially inquired if a long-span bridge using teeth Nos. 4 and 8 as abutments was feasible. However, this was abandoned due to the long pontic span, minor draw issues between the abutments, and the moderate buccal cantilever force that would be imparted by the curved region of the arch being restored once loaded. A recent retrospective study concluded that long-span prostheses, which were defined as those with 5 units or more, may be associated with more complications when compared with shorter span prostheses.3 Furthermore, due to the patient's age-affected dexterity and eyesight, the decision to place shorter implant-supported bridges would result in only the pontic for tooth No. 6 requiring the use of a floss threader.4
Because the patient had a healthy implant replacing tooth No. 10, The final prosthetic plan called for a 3-unit, full-contour zirconia bridge with implant abutments at the sites of teeth Nos. 5 and 7 and a 2-unit, full-contour zirconia mesial cantilever bridge on the patient's existing healthy implant at the tooth No. 10 site with a pontic at the tooth No. 9 site. Individual full-contour zirconia crowns were planned to restore teeth Nos. 4 and 8.
Final Restoration Try-In
Prior to trying in any of the zirconia prostheses or metal prosthetic components, all of the cement receiving surfaces were primed with a single-component priming agent containing MDP (Z-Prime™ Plus, BISCO).5 This primer was selected for its unique combination of two active monomers-MDP, a phosphate monomer, and BPDM, a carboxylate monomer-which create a synergistic effect that results in high bond strengths. By applying a primer to zirconia restorations prior to try-in, any salivary contamination can be rinsed off afterward, and the restorations can be dried without negatively affecting the bond strength that they can achieve.6
The patient's provisional bridge was removed, and then any residual temporary cement was cleaned from the natural abutments using an ultrasonic scaler (Figure 1). Next, a gauze was draped over the patient's throat, and the CAD/CAM titanium abutments, which were sandblasted on the distolingual surfaces and primed, were placed (Figure 2). After the prosthetic screws were torqued and retorqued to the manufacturer's specifications, the final bridges and crowns were tried in and adjusted.
Final Restoration Delivery
Once the patient's approval was obtained, the screw accesses were obturated with PTFE tape, being careful to leave a significant air gap to the top of the abutments to aid in minimizing subgingival cement retention (Figure 3). Next, the 2-unit, mesial cantilever bridge was cemented onto the implant abutment at the site of tooth No. 10 with an adhesive resin cement (Duo-Link Universal™, BISCO) and held securely in place while an LED curing light was used to tack cure the facial and lingual surfaces for 3 seconds each (Figure 4). Cleanup was then initiated by using an instrument to break the excess cement from the margins, gently pushing it in the direction of the gingiva (Figure 5). The 3-unit, implant-supported bridge that was abutted by the implants placed at site Nos. 5 and 7 was cemented in similar fashion.
Following cementation of both of the implant-supported bridges, the crown for tooth No. 8 was delivered using the same adhesive resin cement after first placing a light-cure universal adhesive (All-Bond Universal®, BISCO) on the tooth preparation according to the manufacturer's instructions. The crown was held in place and tack cured on the facial and lingual surfaces for 3 seconds each. The cleanup of excess cement was performed immediately following the tack cure and resulted in most of the excess cement breaking off in one large piece (Figure 6). The adhesive resin cement that was used in the esthetic zone in this case was selected because of its translucent nature.
Finally, the individual crown for tooth No. 4 was delivered; however, a self-adhesive resin cement (TheraCem®, BISCO) was used (Figure 7). In this case, the individual crowns for the natural teeth were placed last in order to minimize the marginal cement gap because the bridges cemented onto the implant abutments will not move like natural teeth due to the lack of a periodontal ligament around the implants. The patient was pleased with the final result (Figure 8).
Conclusion
Too often, elderly patients are offered suboptimal treatment plans in the form of removable prostheses or the continuation of a patchwork restorative philosophy. This case demonstrates how having meaningful discussions with elderly patients that result in appropriate treatment plans involving the use of high-quality materials can provide predictable and long-lasting solutions to their complex dental problems.
About the Author
Joseph Kim, DDS
Private Practice
Chicago, Illinois
Manufacturer Information
BISCO
bisco.com
800-247-3368
References
1. Slade GD, Akinkugbe AA, Sanders AE. Projections of U.S. edentulism prevalence following 5 decades of decline. J Dent Res. 2014;93(10):959-965.
2. Foiles Sifuentes AM, Castaneda-Avila MA, Lapane KL. The relationship of aging, complete tooth loss, and having a dental visit in the last 12 months. Clin Exp Dent Res. 2020;6(5):550-557.
3. Alenezi A, Aloqayli S. Technical complications with tooth-supported fixed dental prostheses (FDPs) of different span lengths: an up to 15-year retrospective study. BMC Oral Health.2023;23:393.
4. Ahuja S, Wicks R, Selecman A. Fabrication of new restorations with a consideration of oral hygiene. J Indian Prosthodont Soc. 2016;16(3):307-310.
5. Fouquet V, Dantagnan CA, Abdel-Gawad S, et al. In vitro shear bond strength over zirconia and titanium alloy and degree of conversion of extraoral compared to intraoral self-adhesive resin cements. BDJ Open. 2023;9:54.
6. Angkasith P, Burgess JO, Bottino MC, Lawson NC. Cleaning methods for zirconia following salivary contamination. J Prosthodont. 2016;25(5):375-379.
