SummaryDental caries continues to be a public health issue, especially more evident in underservedpopulations throughout the U.S. Unfortunately, especially with an ageing population, hundredsof thousands of resin composite restorations are replaced each year due to recurring decay andfracture. According to a number of cohort studies, the average life-span of this type ofrestoration is 7 years or less, depending on the caries risk level of the patient and on thecomplexity of the restorative procedure. Class V lesions, carious or non-carious in nature, areparticularly challenging to restore due to the location of the margins (often in dentin/cementum),the complexity of load distribution in this area of the tooth and the tendency for greater biofilmaccumulation near cervical areas. This proposal represents an effort to develop novel pH-responsive, self-sterilizing methacrylamide composites capable of overcoming theaforementioned difficulties and increasing service life of class V restorations, thus savingmillions of dollars annually and the unnecessary loss of additional tooth structure. The proposedapproach will improve the longevity of class V restorations by: 1. Designing monomers, basedon biocompatible carboxybetaine (CB) chemistry, that are capable of responding to acidicchallenges in the oral environment and performing the dual function of antifouling surfaces (atneutral pH) and bactericidal surfaces (at low pH). 2.Utilizing polymerizable functionalities thatdepart from the water/esterase-labile methacrylates. Methacrylamides are well known for theirresistance to degradation by hydrolysis, and the systems proposed here will also be stable toenzymatic attack (through the use of tertiary methacrylamides). 3. Incorporating tougheningadditives, based on pre-polymerized thiourethanes, which not only reduce the concentration ofpolymerizable functionalities (thus reducing shrinkage), but can also delay polymer gelation(thus reducing stress). In addition, the oligomer will be functionalized to work as a carrier of theCB moiety. 4. Promoting self-adhesive, ionic/covalent interaction between the substrate and theadhesive layer, in addition to the already existing micro-mechanical interlocking. This will allowfor the use of less aggressive (if any) acid etching of the substrate, decreasing activation ofdeleterious MMPs.
|Effective start/end date||7/1/16 → 3/31/19|
- National Institutes of Health: $377,480.00