Adhesive Dentistry: 2013 and Into the Future
With the recent founding of the International Academy for Adhesive Dentistry (IAAD), scientific research, commercially available products, and clinically proven protocols will be brought together with the dental profession.
The recent 5th International Congress on Adhesive Dentistry (ICD), held this past June at the University of Pennsylvania in Philadelphia, summarized three decades of research in material developments and technical innovations in the field of adhesive dentistry. This biannual conference was attended by more than 550 of the world’s top adhesive clinicians, teachers, and researchers from over 20 countries. Founded 10 years ago under the leadership of Japanese researchers and manufacturers, the ICD is an academic and commercial partnership whose goal has been to connect with the larger community of practicing clinical dentists around the world.
The ICD’s desire is now unfolding with the founding of the International Academy for Adhesive Dentistry (IAAD), which officially occurred at the Congress meeting in Philadelphia. The elected President and President-Elect are, respectively, Jean-Francois Roulet, DDS, from the University of Florida and Markus Blatz, DMD, PhD, Dr med dent habil, from the University of Pennsylvania. Their vision is to create an organization that unites scientific research, commercially available products and clinically proven protocols with the dental profession. Interested organizations and companies that have been promoting adhesive dental techniques will be invited to connect with this international group.
A number of organizations had representatives at this founding meeting, including the Japanese Society of Adhesive Dentistry, International Association of Dental Research, Academy of Operative Dentistry, World Congress of Minimally Invasive Dentistry, and Academy of Biomimetic Dentistry. Other organizations from Asia and Europe were also represented. This is a major step toward bringing the “silent revolution”1 of adhesive dentistry into the forefront of the profession and making progress in the advancement of more extensive adhesive protocols in academic teaching and private practice. It will bring about a more conservative approach by students and graduating dentists, which, in turn, will benefit their patients.
No Standardized Protocols
Currently, in 2013, there are no standardized adhesive treatment protocols in dental schools in the United States, Europe, or Asia. All schools are training their students with a developing set of protocols from individual faculty members. Certain textbooks like Summit, Hilton, Robbins, and Schwartz’s Fundamentals of Operative Dentistry (Quintessence, 2006) have outstanding chapters on adhesive principles and practices. But the vast majority of dental curriculums still lack the total commitment to the superiority of advanced adhesive (biomimetic) practices.
The IAAD, created to promote the transfer of research and clinical trials from academia and commercial development into clinical practice, could provide leadership to promote the best practices in the field of adhesive conservative dentistry. Progressive dental schools such as the Tokyo Medical and Dental University; the University of Geneva, Switzerland; the federal University of Santa Catarina, Florianopolis, Brazil; the University of Southern California; the Catholic University of Leuven, Belgium; Osaka Dental College; Hokkaido University, Sapporo, Japan; Tsurumi University, Yokohama, Japan; Selcuk University in Turkey, and the Universities of Florida, Iowa, Pennsylvania, North Carolina, and Tennessee in the United States are all examples of institutes that have embraced a greater role for adhesive dentistry in their curriculums. These changes from traditional, mechanically based restorative techniques have come from individual faculty members who have worked to educate other faculty members. Eventually, schools may reach a “tipping point” where the majority of instructors are teaching students conservative adhesive techniques.2
Accepted Fundamentals
Many outstanding teachers in adhesive dentistry made presentations at the ICD meeting. Some key elements of accepted fundamentals outlined at the conference are briefly summarized as follows (ICD presenters' names in parentheses):
• The hybrid layer created by modern dentin bonding systems (DBS) can be very close to the cohesive strength of dentin; moreover, these systems can create a seal that prevents microleakage.3 (Nakabayashi, Tagami, Van Meerbeek, Nikaido, Sano, Imazato)
• Predictable bonding to caries-affected dentin has been established.4 (Tagami, Nikaido, Momoi)
• Caries-affected dentin will remineralize after the sealing of the dentin with DBS.5 (Tagami, Nikaido, Momoi, Imazato)
• Self-etch dentinal bonding systems have become comparable to 4th generation etch-and-rinse DBSs.6 (Van Meerbeek, Tagami)
• Self-etch adhesives create an acid-based resistance zone (ABRZ) that has been termed “super dentin” because it cannot be dissolved with extreme acidic and basic challenges.7 (Tagami, Nikaido)
• The development of these high bond strengths are jeopardized when the cavity configuration (C-Factor) is too great.8 (Ferracane)
• Modern restorative composites shrink 1% to 3%; this shrinkage does weaken and/or break dentin bonds.8 (Ferracane)
• The modulus of elasticity and polymerization dynamics of any composite have an effect on the stress being transmitted to the developing hybrid layer.8 (Ferracane)
• Matrix metalloproteinases and capthesins degrade the hybrid layer but can be neutralized with different therapeutic agents.9 (Pashley, Breschi, Carvalho, Imazato)
• Sealing the dentin before the impression for an indirect inlay or onlay increases the bond strength and life of the restoration significantly.10 (Dietschi)
• Subgingival margin can be restored with a composite base. This will support long-term (more than 15 years thus far) inlay and onlay restorations.11 (Dietschi)
• Long-term Class V studies show that resistance and retention forms are not only unnecessary but contraindicated because they increase stresses from C-Factor. (Swift, Tagami)
• Semi-direct and indirect restorations are less stressful to the hybrid layer when immediate dentin sealing and resin coating techniques are used. (Dietschi, Nikaido)
• Chemical-cured bulk-filling materials are less stress-producing than light-cured bulk-filled materials but have lower moduli of elasticity with increased visco-elasticity. (Ferracane)
• Different testing methods of bond strengths are becoming standardized and can be related to clinical outcomes. (Momoi, Van Meerbeek)
• Long-term clinical trials are the best guide for clinicians. (Swift)
Other Key Issues
Other topics that were not addressed in-depth at the ICD conference but will be part of the IAAD’s agenda based on published research and practice-based clinical trials are:
• Fiber-net placement can relieve polymerization stresses and increase marginal seal of a restoration. (Belli)
• Air abrasion can increase the bond strength of an adhesive restoration. (Van Meerbeek)
• Managing incomplete tooth fractures.12
• Why posts are not needed for most adhesive reconstructions. (Dietschi)
• How micro-movements of teeth stress bonds, and which material and techniques can withstand these stresses in a biomimetic way.12
• How the polymerization dynamics of different materials create different stresses to the hybrid layer. (Ferracane)
• How different layering techniques can decrease stress and increase bond strength.14
• How slow-start light-curing protocol can reduce polymerization stress. (Ferracane)
• Why glass-ionomer cement (GIC) and resin-modified GIC (RMGIC) sandwich techniques have shorter clinical success rates.13
• Reconstructing structurally compromised teeth without full-coverage crowns.14
The future is bright for adhesive dentistry. By uniting with like-minded clinicians around the world, progress will be made in adhesive dental treatments that conserve tooth structures and maintain pulp vitality—goals that benefit all patients.
REFERENCES
1. Roulet JF, Degrange M. Adhesion: The Silent Revolution in Dentistry. Chicago, IL: Quintessence Publishing; 2000.
2. Magne P. Composite resin and bonded porcelain: the postamalgam era? J Calif Dent Assoc. 2006:34(2):135-147.
3. Nakabayashi N, Pashley DH. Hybridization of Dental Hard Tissues. Chicago, IL: Quintessence Publishing; 1998.
4. Nakajima M, Ogata M, Okuda M, et al. Bonding to caries-affected dentin using self-etching primers. Am J Dent. 1999;12(6):309-314.
5. Akimoto N, Yokoyama G, Ohmori K, et al. Remineralization across the resin-dentin interface: in vivo evaluation with nanoindentation measurements, EDS, and SEM. Quintessence Int. 2001;32(7):561-570.
6. De Munck J, Mine A, Poitevin A, et al. Meta-analytical review of parameters involved in dentin bonding. J Dent Res. 2012;91(4):351-357.
7. Nikaido T, Weerasinge D, Waidyasekera K, et al. Assessment of the nanostructure of acid-base resistance zone by the application of all-in-one adhesive systems: Super dentin formation. Biomed Mater Eng. 2009:19(2-3):163-171.
8. Ferracane JL. Buonocore Lecture. Placing dental composites—a stressful experience. Oper Dent. 2008;33(3):247-257.
9. Carrilho MR, Geraldeli S, Tay F, et al. In vivo preservation of the hybrid layer by chlorhexidine. J Dent Res. 2007;86(6):529-533.
10. Dietschi D, Spreafico R. Current clinical concepts for adhesive cementation of tooth-colored posterior restorations. Pract Periodontics Aesthet Dent. 1998;10(1):47-54.
11. Magne P, Spreafico RC. Deep margin elevation: a paradigm shift. American Journal of Esthetic Dentistry. 2012;2(2):86-96.
12. Magne P, Boff L, Oderich E, Cardoso AC. Computer-aided-design/computer-assisted-manufactured adhesive restoration of molars with a compromised cusp: effect of fiber-reinforced immediate dentin sealing and cusp overlap on fatigue strength. J Esthet Restor Dent. 2012;24(2):135-146.
13. Opdam NJ, Bronkhorst EM, Roeters JM, Loomans BA. Longevity and reasons for failure of sandwich and total-etch posterior composite resin restorations. J Adhes Dent. 2007;9(5):469-475.
14. Deliperi S, Bardwell DN. Clinical evaluation of direct cuspal coverage with posterior composite resin restorations. J Esthet Restor Dent. 2006;18(5):256-267.
About the Authors
David S. Alleman, DDS
Co-director, Alleman-Deliperi Centers for Biomimetic Dentistry, South Jordan, Utah; Dr. Alleman has spent more than 11 years pioneering the development of biomimetic, noninvasive dental procedures that conserve teeth.
Simone Deliperi, DDS
Co-director, Alleman-Deliperi Centers for Biomimetic Dentistry, Cagliari, Sardinia, Italy; Adjunct Assistant Professor, Operative Dentistry Faculty, Tufts University School of Dental Medicine, Boston, Massachusetts
