User:JeffDaviesDDS

Biomimetic Dentistry
Biomimetic dentistry is a branch of dentistry that treats weak, fractured, and decayed teeth in a way that keeps them strong and seals them from bacterial invasion. Careful sealing against infection removes the need for 60% to 90% of the crowns and root canals of traditional dentistry.

History
Over the last 15 years, there has been a steady evolution in the restorative approach with a progression from mechanical retention to advanced adhesion. This transition has been fostered by a wealth of scientific publications, improvements in adhesive materials, and most importantly dissemination of the science and techniques of advanced adhesion all around the world. Collectively, the science, principles, and techniques of advanced adhesive dentistry is known as Biomimetic Dentistry. At its core, the biomimetic approach respects the simple philosophy that we must “mimic life” and understand the natural tooth in its entirety to adequately restore teeth.

Naturally, conserving more of the intact tooth is paramount to this approach, and pairs perfectly with adhesion. The need for mechanical retention, and excessive preparation for full coverage restorations is eliminated. Properly applied, adhesion is best able to preserve marginal integrity and prevent leakage and gaps. Additionally, the adhesively restored tooth is best able to handle and manage functional stresses similarly to the intact natural tooth. As a result, the biomimetically restored tooth eliminates gaps under restorations and cracks into dentin that develop as a result of deformation and stress concentrations. Postoperative pain and sensitivity are eliminated, and vitality is preserved as bacteria are not able to invade and kill the pulp. The natural flexibility and fracture resistance of a  tooth is also enhanced when it is hydrated by the vital pulp.

Biomimetic protocols are founded on the “silent revolution” of adhesive dentistry that developed in the 80s and 90s. This revolution was advanced by Japanese researchers who identified two different layers of carious dentin that had two different characteristics of dentin adhesion. These researchers were able to predictably bond to dentin by using the novel technology of a caries detecting dye which allowed an ideal caries removal end-point (CRE) to be visualized in the all important “peripheral seal zone”(PSZ). On a dentin surface free of denatured collagen, a bond to dentin could be established using newly developed  polymerizable monomers that were both hydrophilic and hydrophobic. With these two technological breakthroughs, Dr Takao Fusayama and his team of researchers at Tokyo Medical and Dental School began the quest for conservative long lasting adhesive restorations. The Universities of Zurich and Geneva in Switzerland, Nijmegen U and ACTA in the Netherlands and the Catholic University in Leuven, Belgium were among the leaders in this quest in Europe. For the next 2 decades advances in materials and techniques allowed more extensive dental defects to be restored in both anterior and posterior regions of the mouth.

Fast forward to 2002. A landmark book was published that advanced major concepts in biomimetic dentistry, including the properties of natural teeth, their behavior under function, preparation design principles, and the all important foundational biomimetic  concept of Immediate Dentin Sealing. In the same year a technique to reduce the effects of polymerization shrinkage stress was published, that allowed a biomimetic approach to a direct composite restoration. This technique is referred to as a Stress-Reduced Direct Composite. With these two publications the protocols listed below were becoming known to the dental profession around the world. Today, two organizations of biomimetic restorative dentists have been organized and have held yearly meetings since 2011: The Academy of Biomimetic Dentistry and the Bio-Emulation Colloquium. The Biomimetic Study Club is an emerging non profit group that focuses on unifying many of the prominent biomimetic educators with the intent of aiding biomimetic dental research. Many prominent speakers from around the world are presenting at other meetings and increasingly dentists are embracing the sound concepts and benefits of the biomimetic approach.

Biomimetic Paradigms
There are four basic biomimetic paradigms that biomimetic restorative dentistry is founded on:

BP #1- Maximum bond strength: Reducing polymerization stress to the developing hybrid layer(HL) results in a 300-400% increase in bond strength(16,17,18,19). Dentin bond strengths in the range of 30-60 MPa is the same range as the tensile strengths of enamel, DEJ and dentin. (20). This strong bond allows the biomimetically restored tooth to function and handle functional stresses like the intact natural tooth.

BP #2- Marginal Seal: A strong and secure bond allows the marginal seal to be established and maintained long term during functional stresses. (3,21,22,23,34).

BP #3- Pulp Vitality:  By maintaining the highly bonded seal, the restoration will function long term without recurrent decay, dental fractures, or pulp deaths (3,24,25,48). A vital tooth is also 3X more resistant to fracture (49).

BP #4: Decrease Residual Stress:  Residual stress, while hard to visualize, leads to cuspal deformation, debonding, gaps, cracks, pain and sensitivity, and recurrent decay. Reducing residual stress while maintaining maximum bond strength are ideal goals for a biomimetic restorative technique.

Biomimetic Protocols and Concepts
The biomimetic restorative protocols that will produce these results can be divided into two groups. In the first group are 10 key stress reducing protocols (SRPs) which produce stress reduction to the developing hybrid layer as it is formed and throughout the life of the restoration under function.(3,34)

The second group of 8 key protocols is termed Bond Maximizing Protocols (BMPs)  These BMPs insure the maximum bond strengths possible from the stress reducing protocols. Using the BMPs will ensure the most benefit from employing the SRPs.

When performing a biomimetic restoration, it is vital to visualize the accomplishment of the protocols. Magnification in the 5X-8X range is highly recommended (9) when performing a biomimetic restoration. The use of a surgical microscope or high-powered loupes makes treatment very predictable. You are only able to diagnose and treat what you can properly visualize.