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Title Longevity of Dental Amalgam and Resin Composite is Comparable
Clinical Question For a relatively healthy patient who requires a class I or II dental restoration, will the type of dental material used to restore the lesion, specifically dental amalgam versus resin composite, impact the longevity or failure rate of the restoration?
Clinical Bottom Line In terms of longevity, it appears that both materials, dental amalgam and resin composite, are comparable. In larger restorations, amalgam may be the material of choice as its failure rates are slightly lower than resin composite, especially for patients at high risk for caries. (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) 11317384Hickel/2001Patients requiring restorations in the permanent posterior dentitionMeta-Analysis
Key resultsAnnual failure rates in posterior stress-bearing restorations are: 0% to 7% for amalgam restorations and 0% to 9% for direct composites. The main reasons for failure include: secondary caries, fracture, marginal deficiencies, wear, and postoperative sensitivity.
#2) 17545266Bernardo/2007Young patients who require posterior dental restorationsRandomized Control Trial
Key resultsAuthors followed the patients for up to seven years. Overall, 10.1 % (out of 1,748 total restorations placed) failed. The survival rate of the amalgam restorations was 94.4%; that of composite restoration was 85.5%. Annual failure rates ranged from 0.16 to 2.83 percent for amalgam restorations and from 0.94 to 9.43 percent for composite restorations. Secondary caries was the main reason for failure in both materials. Risk of secondary caries was 3.5 times greater in the composite group. Amalgam restorations performed better than did composite restorations. “Use of amalgam appears to be preferable to use of composites in multi-surface restorations of large posterior teeth if longevity is the primary criterion in material selection.”
#3) 17545265Soncini/2007Children ages 6 to 10 years requiring posterior dental restorationsRandomized Control Trial
Key resultsIn permanent teeth, the replacement rate was 14.9% of composites versus 10.8% of amalgams, and the repair rate was 2.8% of composites versus 0.4% of amalgams. Although the overall difference in longevity was not statistically significant composite restorations requires seven times as many repairs as did amalgam restorations.
#4) 20660797Opdam/2010patients from one private practiceretrospective cohort study
Key resultsAfter 12 years, 293 amalgam and 114 composite restorations failed of a sample of 1949 class II restorations. Large amalgam restorations showed better survival than composite ones especially in high caries risk patients while large composites survival was better for large restorations in low caries risk patients.
Evidence Search amalgam AND resin composite AND longevity ...view in PubMed
Comments on
The Evidence
The first article is a comprehensive search for relevant trials that were closely followed for over a decade. The studies were assessed for validity and the results were summarized. This article represented a meta-analysis. Overall, this article is valid. The second article is not a systematic review, though the trials were assessed for validity. A total of 1,748 patients were examined that ranged in age from 8 to 12. The third article is another Randomized Control Trial conducted on children ages 6 to 10. 267 restorations were made on permanent teeth and the validity of the results were assessed. The replacement rate of composite versus amalgam has a p value of 0.45.
Applicability These articles are applicable to the patient group in question (i.e. patients who need a posterior restoration).
Specialty/Discipline (Endodontics) (General Dentistry) (Pediatric Dentistry) (Periodontics) (Restorative Dentistry)
Keywords Resin Composites; Dental Amalgams; Longevity
ID# 602
Date of submission: 04/02/2010spacer Revised: 02/02/2012
E-mail williamser@livemail.uthscsa.edu
Author Erica Williams
Co-author(s) e-mail
Faculty mentor/Co-author Joseph Connor, DDS
Faculty mentor/Co-author e-mail connorj@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
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by James McPherson, Steve Meier, Roberto Olivares (San Antonio, TX) on 01/07/2013
We agree with the clinical bottom line of this CAT but would like to note that the Longevity of the resin restorations is similar to Amalgam when the Resin was a hybrid and microfill composite and was placed using the enamel-etching technique and a rubber dam, based upon the findings in PMID 23082310 .

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