Biomimetic Dentistry: Class II direct composite restorations
According to traditional adhesive dentistry, clinical success with direct composite restorations relies mainly on the proper selection and use of high performing adhesive systems.
The stress generated from polymerization shrinkage and the lack of adequate protocols have discouraged many clinicians from selecting a direct technique for the restoration of class II cavities for many years.
Biomimetic dentistry still utilizes advanced adhesive dentistry techniques, but also adopts protocols able to maximize the bond and minimize the stress in Class II direct composite restorations. These restorations are called stress-reducing direct composite (SRDC) restorations. Both the maturation of the bond, the strategic layering and curing protocols are the milestone for stress reduction on the residual cavity walls. The goal of stress-reducing direct composite (SRDC) restorations is to mimic the functional and optical characteristics of the intact natural tooth.
The clinical protocol for stress-reducing direct composite (SRDC) restorations was first published in the JADA in 2002 and has been further developed in the last 15 years (Deliperi & Bardwell, 2002, 2006; Deliperi & Alleman, 2009; Deliperi et al. 2011).
Stress-reducing direct composite (SRDC) restorations have become a valid alternative to indirect resin-bonded composite restorations over the years (Deliperi & Bardwell, 2002, 2006; Deliperi, 2008; Deliperi & Alleman, 2009; Deliperi, Bardwell, Alleman, 2012; Deliperi 2012). After 15 years of clinical success with SRDC, Dr Deliperi teaches clinicians to preserve the remaining sound tooth structure in both medium, large size restorations and cusp-replacing restorations to either resist the mode of failure or mimic the performance characteristics of the intact natural tooth!
Six basic steps will be followed during the hands-on course to complete stress-reduced direct composite (SRDC) restorations: 1. Analysis of the occlusion and opposing dentition; 2. Cavity preparation and caries removal endpoints; 3. Analysis of residual tooth structure; 4. Preparation of the dental substrate to achieve a reliable bond to enamel and dentin; 5. Control of polymerization stresses by using appropriate layering and curing techniques; 6. Occlusal force equilibration (Deliperi 2012).
With a solid scientific background in mind and a continuous training, clinicians may perform restorations able to recover the original strength of the natural teeth. No prophylactic endo, no posts, no traditional crowns are required anymore even in the most structurally compromised teeth!
As Dr Deliperi stated in 2010: “the more structurally compromised is the tooth the more conservative and biomimetic we need to be”.
The second part of this article will cover the use of polyethylene fibers in the restorations of structurally compromised teeth according to the wall-papering technique (Deliperi et al. 2017).