Does the wear resistance of packable composite equal that of dental amalgam?
BACKGROUND
There is little evidence that packable composites are sufficiently wear resistant to be used as an alternative to amalgam.


OBJECTIVE
The purpose of this study was to evaluate wear rates of packable composites compared with hybrid resin composites and amalgams by an in vitro wear test.


METHODS
The following composites were used: three packable composites (SureFil, Dentsply/Caulk, Milford, DE, USA; Alert, Pentron Clinical Technologies, Wallingford, CT, USA; and Solitaire, Heraeus Kulzer, Wehrheim, Germany), two hybrid resin composites (TPH Spectrum, Dentsply/Caulk; and Pyramid enamel, Bisco Inc., Schaumburg, IL, USA), and two amalgams (Tytin, Kerr Manufacturing Co., Romulus, MI, USA; and Dispersalloy, Dentsply/ Caulk). Cylindrical Class I cavities prepared on occlusally flattened, extracted human molars were restored with respective materials according to the manufacturers' instructions. Generalized, localized, and antagonistic enamel wear tests were carried out by a University of Alabama at Birmingham (UAB) wear simulator according to previously reported methods. Seven specimens were tested for each group, and the wear depths were measured on profilometric tracings. The data for each wear mode were independently analyzed by one-way analysis of variance and Fisher's exact test (p < or = .05).


RESULTS
The generalized wear values for SureFil (7.0 +/- 3.5 microm), Alert (8.6 +/- 1.8 microm), and Pyramid (3.9 +/- 0.5 microm) were not statistically different from those of amalgam materials (Tytin 5.8 +/- 0.7 microm, Dispersalloy 6.0 +/- 0.9 microm) but were different from those of Solitaire (23.9 +/- 2.6 microm) and TPH (30.6 +/- 5.5 microm). The localized wear values for SureFil (19.8 +/- 14.2 microm) and Alert (28.0 +/- 1.6 microm) were significantly smaller than for all other materials. For antagonistic enamel wear, Solitaire exhibited a minimal value (3.4 +/- 0.9 microm), whereas values of SureFil (12.6 +/- 5.6 microm) and Alert (12.0 +/- 6.6 microm) were not statistically different from those of TPH (11.0 +/- 4.0 microm) and amalgams (Tytin 14.5 +/- 4.3 microm, Dispersalloy 7.8 +/- 3.3 microm).


CONCLUSIONS
It can be concluded that SureFil and Alert packable composites possess similar wear resistance and abrasiveness to amalgam on the basis of the limitations of this study, which simulated 3 years of clinical wear.
Suzuki
Shiro
S
Department of Prosthodontics and Biomaterials, University of Alabama at Birmingham School of Dentistry, Birmingham, AL 35294-0007, USA. Shiro@mail.dental.uab.edu
D000180:Acrylic Resins / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D003722:Dental Alloys / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry*; D019554:Dental Restoration Wear; D006801:Humans; D008422:Materials Testing / Q000379:methods; D008689:Methacrylates / Q000737:chemistry; D008963:Molar; D011140:Polyurethanes / Q000737:chemistry*
D000180:Acrylic Resins; C406265:Alert composite resin; C029012:Composite Dental Resin; D003188:Composite Resins; D003722:Dental Alloys; D008689:Methacrylates; D011140:Polyurethanes; C428803:Pyramid Packable Composite; C113049:Solitaire composite resin; C420128:Spectrum composite resin; C403464:SureFil packable composite; C033470:Dispersalloy; C036886:tytin; D003723:Dental Amalgam