The Use of a Hybrid Pillar and Its Importance for Aesthetic Rehabilitation and Tissue Stability: A Clinical Report
In the past, aesthetics had a secondary role in implant rehabilitation. Nowadays, the search for a perfect and harmonious aesthetic has stimulated the development of new materials and techniques. Due to this aesthetic requirement, the hybrid abutment (titanium link + zirconia) emerged as an alternative to metallic pillars. The hybrid abutment made a more favorable aesthetic possible, provided reliable mechanical properties, and increased biocompatibility to the surrounding tissues. Additionally, the individual zirconia abutment improves the emergency profile and the final white aesthetics. The objective of this paper is to report a clinical case with a manufactured individualized hybrid abutment for a metal-free indirect restoration, showing the applicability, mechanical properties, and biocompatibility of the hybrid abutment.
Aesthetic demands led us to new concepts and prosthetic resources in dentistry. We now use new materials with optical, mechanical, and biological properties . Zirconia abutment fabrication and metal-free-implant-supported prostheses favor a better aesthetic situation than the metal counterpart . These methods allow translucency in dental restoration, provide gingival tissue shade reduction, and result in a very natural and healthy appearance .
The aesthetic success of implant-supported prostheses is strongly related to the surrounding soft tissue appearance. Unlike metal abutments, which cause an unpleasant appearance in a fine gingival biotype , the use of zirconia abutment allows light scattering and customization for each individual case. This creates an emergence profile that provides color, shape, and gingival symmetry similar to natural teeth [4, 5].
As observed in several studies, zirconia has shown satisfactory results in aesthetic of prosthetic crowns as well as in adjacent gingival tissues [2, 7–11]. Due to the increase of the use of aesthetic abutments and restorations, new technologies have appeared, such as CAD/CAM systems [12, 13].
The CAD/CAM system consists of a planning and production computerized system for crowns, facets, inlays, onlays, crown copings, implant abutments, and even zirconia structures for fixed and removable partial prostheses. Through this system, pieces are fabricated with quality, high accuracy, minimal human intervention, error reduction during production, and lowered manufacturing costs [13, 14].
The objective of this paper was to show the importance of aesthetic customized prosthetic abutment and its indications and advantages and disadvantages, along with a clinical case presentation.
2. Case Presentation
A 46-year-old male patient with absence of element 24 presents with a need for aesthetic rehabilitation. The patient had tooth extraction indicated due to root fracture. After Anthogyr PX 4.0 × 8 mm implant installation, a provisional restauration for gingival tissue maintenance was made, in respect of the ideal critical and subcritical contour, providing a more predictable and stable gingival emergence profile.
During the osseointegration period (120 days), the temporary customized crown did not have any occlusal contact. After this period, the acrylic temporary crown, previously prepared, was adjusted. For a better gingival tissue conditioning, we proceeded with temporary crown reassembly. Figures 1(a) and 1(b) display the temporary component properly prepared and screwed on the implant.
Figure 2 shows an excellent emergence profile and the quality of the soft tissue obtained by the provisional component that was made in respect of the gingival biotype, and a concave critical and subcritical transmucosal emergence profile ensured the soft tissue quality [15#x2013;17].
Even though the working cast reproduces the clinical situation faithfully (Figure 5), we proceeded with the rehabilitation using the CAD/CAM technology-customized zirconia (hybrid) for link abutment (FLEXIBASE®, Anthogyr) which offers advantages over prefabricated ones.
Figure 6(a) enables us to observe that through this technology, the gingival margin is delimitated in order to make the abutment emerge throughout the soft tissue as similar as a natural clinical crown (Figure 6(b)).
Once the crown is designed, the outer part of the abutment is adjusted to create support and to provide retention which is achieved by planning an ideal proportion between the hybrid abutment and restorative crown, interocclusal space, and cementation line appropriated to the final restoration (Figures 8 and 9).
To cement the zirconia abutment in the link abutment, the flex base, the bonding surfaces of the titanium, and the zirconia ceramic were air-abraded with 50 mm aluminum oxide particles at 2.0 bars of pressure (0.25 MPa) for 20 seconds at a distance of 10 mm, after which they were cleaned in alcohol and then cemented using a resin luting (Relyx U200, 3M ESPE®) . Excess resin was removed from the bonding margins before it became fully set and was light-cured per the manufacturer’s recommendations.
The hybrid abutment was placed (Figure 12) with 25 N definitive torque, and the crown was cemented using a resin luting (Relyx U200, 3M ESPE).
The clinical results (Figures 13 and 14), one month after prosthesis installation, prove the component adaptation placement and the quality in the contour of the gingival tissues. The successful aesthetic can be noticed by the smile harmony, color, texture, and natural brightness in comparison to the adjacent teeth.
Dental implant treatment for dental element replacement considering the maintenance of gingival architecture and restoration has occurred for some years. However, by pursuing better aesthetics, hybrid abutments have surpassed metal abutments and provide a more natural appearance to the ceramic restorations.
CAD/CAM systems enabled the fabrication of the customized zirconia for link abutments that are individualized for both the anterior region and posterior teeth. Nowadays, through the CAD/CAM technology, hybrid abutment can be designed and manufactured ensuring mechanical characteristics of the materials [13, 19, 20].
CAD/CAM systems present several advantages, such as fast production, biocompatibility, aesthetics, and mechanical resistance with low fracture rate (because the blocks are industrially produced and have high homogeneity, without the need for refractory casts) [21, 22]. Furthermore, they enable excellent adaptation between margin restoration and soft tissues [23, 24].
There are several studies comparing metal and hybrid abutment characteristics . Taking aesthetics into consideration, it was observed that hybrid abutments did not give grayish appearance to the gingival margin as noticed when metal abutments were used. This is a great advantage, especially to patients who have a high smile line and fine gingival genotype .
Studies have shown that the zirconia oxide presents mechanical resistance similar to titanium. This property combined with new automated techniques (CAD/CAM) made the use of hybrid abutment possible in rehabilitation both in the anterior region and in regions with higher masticatory load [13, 21, 24–28].
Material biocompatibility is very important for the longevity of implant-supported restorations. A great deal of studies observed that zirconia has presented low bacterial adherence, and hybrid abutments accumulate bacteria with lower pathogenic potential in relation to titanium abutments [6, 7].
Single hybrid abutments have aesthetics, mechanical resistance, and biocompatibility which enable metal components to be replaced in implanted supported prostheses. However, each case should be evaluated carefully as these components were recently introduced to the market and there are no long-term studies on their clinical use.
Conflicts of Interest
The authors declare that there are no conflicts of interest regarding the publication of this paper.
R. Faria and M. A. Bottino, “Zircônia monolítica de alta translucidez na reabilitação sobre implantes,” PróteseNews, vol. 3, no. 1, pp. 36–50, 2016.View at: Google Scholar
S. A. Gehrke, P. C. V. Dos Santos, N. T. A. Carvalho, R. M. De Mello, and M. J. Carbonari, “Abutment cerâmico para prótese individual metalfree sobre implante: parafusada ou cimentada - demonstração laboratorial e clínica,” Full Dentistry in Science, vol. 1, no. 3, pp. 248–253, 2010.View at: Google Scholar
M. Anderson, M. E. Razzoog, A. Odén, E. A. Hegenbarth, and B. R. Lang, “Procera: a new way to achieve an all-ceramic crown,” Quintessence International, vol. 29, no. 5, pp. 285–296, 1998.View at: Google Scholar
P. Odman and B. Andersson, “Procera AllCeram crowns followed for 5 to 10.5 years: a prospective clinical study,” The International Journal of Prosthodontics, vol. 14, no. 6, pp. 504–509, 2001.View at: Google Scholar
V. M. Barros, B. F. de Oliveira, S. G. de Oliveira, and P. I. Seraidarian, “Intermediário de zircônia,” PróteseNews, vol. 1, no. 1, pp. 52–64, 2014.View at: Google Scholar
L. Rimondini, L. Cerroni, A. Carrassi, and P. Torricelli, “Bacterial colonization of zirconia ceramic surfaces: an in vitro and in vivo study,” The International Journal of Oral & Maxillofacial Implants, vol. 17, no. 6, pp. 793–798, 2002.View at: Google Scholar
R. Scotti, K. Zanini Kantorski, N. Scotti, C. Monaco, L. F. Valandro, and M. A. Bottino, “Early biofilm colonization on polished- and glazed-zirconium ceramic surface. Preliminary results,” Minerva Stomatologica, vol. 55, no. 9, pp. 493–502, 2006.View at: Google Scholar
R. Scotti, K. Z. Kantorski, C. Monaco, L. F. Valandro, L. Ciocca, and M. A. Bottino, “SEM evaluation of in situ early bacterial colonization on a Y-TZP ceramic: a pilot study,” The International Journal of Prosthodontics, vol. 20, no. 4, pp. 419–422, 2007.View at: Google Scholar
A. M. M. Mesquita, R. O. A. Souza, and E. Miyashita, “Restaurações cerâmicas metal free,” in Atualização em clínica Odontológica – Clínica do Dia-a-Dia, pp. 679–719, Artes Médicas, São Paulo, Brazil, 2008.View at: Google Scholar
A. M. M. Mesquita, E. Miyashita, R. O. de Assunção e Souza, R. de Vasconcellos Moura, S. Watinaga, and J. A. Shibli, “A tecnologia CAD/CAM e a zircônia a serviço da prótese sobre implante,” PróteseNews, vol. 2, no. 3, pp. 51–70, 2015.View at: Google Scholar
F. P. Pastor, F. Kfouri, and T. de Mello Rezende, “Confecção de pilares metal free com o uso do sistema CAD/CAM,” PróteseNews, vol. 3, no. 2, pp. 174–183, 2016.View at: Google Scholar
H. Su, O. Gonzalez-Martin, A. Weisgold, and E. Lee, “Considerations of implant abutment and crown contour: critical contour and subcritical contour,” The International Journal of Periodontics & Restorative Dentistry, vol. 30, p. 335, 2010.View at: Google Scholar
E. Rompen, N. Raepsaet, O. Domken, B. Touati, and E. van Dooren, “Soft tissue stability at the facial aspect of gingivally converging abutments in the esthetic zone: a pilot clinical study,” The Journal of Prosthetic Dentistry, vol. 97, no. 6, pp. S119–S125, 2007.View at: Publisher Site | Google Scholar
I. Sailer, T. Sailer, B. Starwarczyk, R. E. Jung, and C. H. Hämmerle, “In vitro study of the influence of the type of connection on the fracture load of zirconia abutments with internal and external implant-abutment connections,” The International Journal of Oral & Maxillofacial Implants, vol. 5, pp. 850–858, 2009.View at: Google Scholar
P. Magne, M. P. Paranhos, L. H. Burnett Jr., M. Magne, and U. C. Belser, “Fatigue resistance and failure mode of novel-design anterior single-tooth implant restorations: influence of material selection for type III veneers bonded to zirconia abutments,” Clinical Oral Implants Research, vol. 22, no. 2, pp. 195–200, 2011.View at: Publisher Site | Google Scholar
M. Morim, “CEREC: the power of technology,” Compendium of Continuing Education in Dentistry, vol. 22, no. 6, pp. 27–29, 2001.View at: Google Scholar
A. Kurbad and K. Reichel, “Multicolored ceramic blocks as an esthetic solution for anterior restorations,” International Journal of Computerized Dentistry, vol. 9, no. 1, pp. 69–82, 2006.View at: Google Scholar
M. Yildrim, D. Edelhoff, O. Hanisch, and H. Spiekermann, “Ceramic abutments—a new era in achieving optimal esthetics in implant dentistry,” The International Journal of Periodontics & Restorative Dentistry, vol. 20, no. 1, pp. 81–91, 2000.View at: Google Scholar
M. A. Bottino, R. Faria, and J. C. Dinato, “Pilares ceramicos em implantodontia: o estado da arte,” in Odontologia Estetica – O Estado da Arte, E. Miyashita and A. S. Fonseca, Eds., vol. 1, pp. 591–633, Artes Medicas, Sao Paulo, Brazil, 2004.View at: Google Scholar
M. A. Bottino, L. F. Valandro, R. Scotti, and L. Buso, “Effect of surface treatments on the resin bond to zirconium-based ceramic,” The International Journal of Prosthodontics, vol. 18, no. 1, pp. 60–65, 2005.View at: Google Scholar