Title Silorane-Based Composite Resin Bonding System Is More Resistant to Chemical and Enzymatic Degradation In Vitro than Traditional Methacrylate System
Clinical Question In teeth restored with dental composite, does a bonding agent based on oxirane chemistry, compared to one with traditional methacrylate chemistry, result in increased stability in the presence of esterases and acids?
Clinical Bottom Line Restorative resin bonding systems based on silorane chemistry instead of methacrylate chemistry show resistance to degradation by esterase and pH activity, which may allow these restorations to last longer in the oral cavity, but there is insufficient research available to show longevity of oxirane/siloxane based resins and bonding systems in clinical situations.
Best Evidence  
PubMed ID Author / Year Patient Group Study type
(level of evidence)
24008178Li/2014336 resin specimens bonded to bovine teethLaboratory study
Key resultsResin-dentin bond strength decreased and dentin demineralization increased for both composite resin systems when challenged with biofilm and sucrose pulsing. However, silorane-based bonding systems (Filtek LS) degraded less than methacrylate-based systems (Z100). Part of the decrease in bond strength may be due to the thinner adhesive layer of the Z100 bonding system.
Evidence Search Resin Composite, Degradation, Bond Strength, Chemistry
Comments on
The Evidence
Validity: Oxiranes are known for their unique ring-opening properties which allow for lower curing shrinkage than methacrylate resins. The siloxane molecule is a hydrophobic monomer which lacks the degradation-prone ester linkages found in methacrylate resins. The combination of the oxirane and siloxane results in a dental resin called silorane. Silorane resins and their use in dentistry are still in a fairly early stage. Li’s study looked at the in vitro effect biofilms have on the composite-dentin interface. The control was a sterile saliva sample only, while experimental samples with biofilms were pulsed with sucrose. The pulsed sample reached an acidity level of below 5.5. Bond strengths were the same for samples with no biofilms. Sucrose-pulsed biofilms induced reductions in bond strength for both materials, but the magnitude of the change was greater for methacrylate-based resin/bonding systems over silorane-based systems. The in vitro studies show the potential for oxirane (silorane) resins to last longer in the oral cavity than methacrylate resins.
Applicability Oxirane/silorane restorations have great potential to extend the longevity of resin restorations through resistance to esterase and pH degradation, but more long-term clinical trials are needed to prove they are an improvement on methacrylate restorations.
Specialty (General Dentistry) (Restorative Dentistry) (Interprofessional CATs)
Keywords Resin Composite, Degradation, Bond Strength, Chemistry
ID# 2795
Date of submission 12/11/2014
E-mail LambertS@livemail.uthscsa.edu
Author Stephen Lambert, DDS
Co-author(s)
Co-author(s) e-mail
Faculty mentor Kyumin Whang, PhD
Faculty mentor e-mail WHANG@uthscsa.edu
   
Basic Science Rationale
(Mechanisms that may account for and/or explain the clinical question, i.e. is the answer to the clinical question consistent with basic biological, physical and/or behavioral science principles, laws and research?)
None available
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Comments and Evidence-Based Updates on the CAT
(FOR PRACTICING DENTISTS', FACULTY, RESIDENTS and/or STUDENTS COMMENTS ON PUBLISHED CATs)
None available