[An in vitro investigation of wear resistance and hardness of three kinds of new composite resins].
OBJECTIVE
To evaluate wear resistance and hardness of three kinds of new composite resins.


METHODS
Three kinds of new composite resins, Solidex, Spectrum, Filtek Z350, were tested. Enamel as control group. A refited MG-200 wear machine was used in this study. Scanning electron microscope (SEM) was used to observe the friction surface of each tested material. Hardness of each tested material was determined by Vickers indentation technique. The data of wear and hardness were analyzed by Mann-Whitney test and 1-way ANOVA. The relationship between the hardness of the composites and the amount of wear of them was determined by a regression analysis method.


RESULTS
Filtek Z350 showed the lowest volumetric wear and highest Vickers hardness in the composites (P < 0.05). No significant differences in wear and hardness were observed between Solidex and Spectrum (P > 0.05). Significant relationships were observed between the hardness of the composites and the amount of wear of them (r = 0.968 6) (P < 0.05). Different wear characters of the friction surface of the tested materials were observed by SEM.


CONCLUSIONS
Nanofilled composite was superior to the hybrid composite in wear resistance and hardness.
Wang
Li-kai
LK
Dept. of Prosthodontics, The Affiliated Stomatology Hospital of Nanchang University, China.
Shi
Lian-shui
LS
Zhu
Hong-shui
HS
D003188:Composite Resins; D003743:Dental Enamel; D003764:Dental Materials; D019554:Dental Restoration Wear; D006244:Hardness; D066298:In Vitro Techniques; D008422:Materials Testing; D013499:Surface Properties
D003188:Composite Resins; D003764:Dental Materials; C113676:Solidex; C533204:filtek Z350