Title	Amalgam Versus Resin Composite Restorative Materials to Prevent Secondary Caries Via Antibacterial Properties
Clinical Question	In a patient with high caries risk, are dental amalgams or resin composites more effective as antibacterial agents in preventing secondary caries?
Clinical Bottom Line	In vitro amalgam certainly showed more antibacterial potential than composite material, but for a high caries risk patient it is not clear whether the amalgam positive benefits of this study will translate into the same results in the oral cavity of patients as opposed to composite. Thus good technique and preparation formation should be considered first priority when considering the formation of secondary caries.
Best Evidence
PubMed ID Author / Year Patient Group Study type (level of evidence) 16996674 Beyth/2007 Several composite types and amalgam dental material inoculated with either S. mutans or Actinomyces viscosus In vitro microorganism Key results Composite resin showed little to no effect on the rate and amount of growth of either S. mutans or A. viscosus. Tetric ceram showed the greatest effect of the composites in inhibiting bacterial growth at confidence of p<0.05. Amalgam however completely stopped all of the phases of bacterial growth for one week before allowing any growth to occur. The results were significant at p<0.0001.
Evidence Search	("Dental Amalgam"[Mesh] AND "Composite Resins"[Mesh]) AND "Anti-Bacterial Agents"[Mesh]
Comments on The Evidence	This is an in vitro study testing materials on microorganisms in the presence of 4 different dental materials and is of low value in its evidence. There was no meta-analysis done in this study.
Applicability	The selection criteria involved three different composite resin restorative materials (Z250, Tetric Ceram, P60) and amalgam in the presence of two types of bacteria commonly thought to be involved in plaque formation (S. mutans and A. viscosus). This evidence is of weak value due to in vitro studies being one of the weakest forms of publishable studies. Despite the results showing amalgam inhibiting the growth of microorganisms much better than composite, it has to be noted that the oral cavity is a much different environment than that of agar plates and wells due to the presence congregations of different mutualistic bacteria in biofilms in plaque as well as constant changing acidity of the oral cavity in addition to other factors. As a result the evidence should not be ignored but certainly the idealism that amalgam is not a substitution for good preparation form or technique as it is highly unlikely that the antibacterial properties of amalgam alone are enough to prevent secondary caries from forming.
Specialty	(Endodontics) (General Dentistry) (Periodontics) (Prosthodontics)
Keywords	Restorative materials, resin composite, dental amalgam, secondary caries, antibacterial
ID#	2456
Date of submission	03/03/2013
E-mail	poupart@livemail.uthscsa.edu
Author	Kyle Poupart
Co-author(s)
Co-author(s) e-mail
Faculty mentor	Karen Troendle, DDS, MPH
Faculty mentor e-mail	troendle@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
Comments and Evidence-Based Updates on the CAT (FOR PRACTICING DENTISTS', FACULTY, RESIDENTS and/or STUDENTS COMMENTS ON PUBLISHED CATs) None available