View the CAT printer-friendly / share this CAT
Title Amalgam and Resin Composite Fillings Show Equal Failure Rates in Small Posterior Restorations while Amalgam Shows Better Survival than Composite if used for large posterior restorations.
Clinical Question In patients with small caries in posterior teeth, do amalgam restorations have lower failure rates than resin composite restorations?
Clinical Bottom Line When comparing the failure rates of amalgam and resin composite in small restorations in posterior teeth, composites and amalgams were statistically no different if the restoration is small and not restoring an interproximal area. Composite has a higher failure rate due to secondary caries if the restoration was larger. (See Comments on the CAT below)
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 11763918Hickel/2000Patients with posterior restorationsMeta Analysis
Key resultsAnnual failure rates in posterior stress-bearing cavities were determined to be 0-9% for direct resin-based composite restorations and 0-7% for amalgam restorations. The median annual failure rate of longitudinal studies for amalgam was calculated at 1.1% and at 2.1% for resin-based composite.
#2) 11317384Hickel/2001Patients with posterior restorationsMeta Analysis
Key resultsLongevity of dental restorations is dependent upon many different factors that are related to materials, the patient and the dentist. The principal reasons for failure were secondary caries, fracture, marginal deficiencies, wear and sensitivity.
#3) 17625635Levin/2007650 restored interproximal spaces in 459 young adults.Retrospective case series.
Key results86(13%) restored interproximal surfaces showed secondary caries and 22(3%) had overhanging restorations. Considering 557 amalgam restorations, secondary caries occurred in 46(8%) while in composite restorations, secondary caries developed in 40(43%).
#4) 20660797Opdam/2010Patient in a private practiceRetrospective case series
Key resultsSurvival of 3, 4/5 surface restorations (1202 amalgams and 747 composite) was studied taking caries risk into account. After 12 years, 293 amalgam and 114 failed. In the high risk caries group, large amalgam restorations showed better survival while in the low risk caries group, large composites demonstrated better survival.
Evidence Search "Composite Resins"[Mesh] AND "Dental Amalgam"[Mesh] AND "Dental Restoration, Permanent"[Mesh]
Comments on
The Evidence
The evidence from the two Hickel studies was the highest level of evidence being two meta-analyses. The Levin and Opdam papers were lower level evidence being retrospective case studies.
Applicability The patient group included in these three studies is representative of a very common clinical diagnosis and treatment encountered by clinicians on a daily basis.
Specialty/Discipline (General Dentistry) (Restorative Dentistry)
Keywords Posterior restorations, Amalgam, Resin Composite
ID# 591
Date of submission: 04/30/2010spacer Revised: 11/15/2012
E-mail willhitel@livemail.uthscsa.edu
Author Lourdes Willhite
Co-author(s) e-mail
Faculty mentor/Co-author Rita Renee Parma, DDS
Faculty mentor/Co-author e-mail PARMA@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?)
post a rationale
None available
Comments and Evidence-Based Updates on the CAT
post a comment
by Vu Le (San Antonio, TX) on 07/09/2012
The evidence from a 2012 study from Overon & Sullivan from UTHSCSA indicates that the failure rates of Class II resin composite restorations have a 10x higher failure rate as those of Class II amalgam restorations. This study emphasizes that clinician proficiency in composite restorations is a significant factor in composite success rate. It is possible that even with small posterior restorations, composite may have a significantly higher failure rate than amalgam with clinicians new to composite.

Return to Found CATs list