It was observed that the material Omega 900 (R) offered significantly greater resistance to compression than the other two materials, which did not present statistically significant difference between them.

RESUMO DESCRIPTORS DESCRITORESResinas compostas; Compômeros; Prótese dentária.

Background: Surface roughness allows dental biofilm to be formed in greater quantities and more quickly on rough surfaces. Biofilm maturation has clinical implications because it intensifies the presence of pathogenic microorganisms. Methods: The specimens (diameter = 10 mm ⁄ thickness = 2 mm) were stored in deionized water for 7 days, and divided into immersion groups (n=10): Coffee, G1; Coca Cola, G2; H2OH lemon refrigerant, G3; immersed for 7 days. Mass (g) was analyzed with a digital scale, and Ra roughness (μm) by readouts on specimen surfaces using a roughness meter. Microbial adherence analysis was performed from a microbial suspension of Streptococcus mutans dispensed in test tubes containing TSB broth with the addition of 1% glucose. Five specimens of the each group were introduced into the mentioned test tubes and incubated at 37ºC/24h. The specimens were then washed in a buffered saline solution (PBS). After this, they were placed in test tubes containing glass micropearls +1 ml of PBS and agitated for 60 second (Phoenix agitator). The microbial suspension was diluted in PBS and plated in triple spots on the surfaces of TSA plates. Results: There was increase in roughness (G1.T0=0.1861, G1.TF=0.2091; G2.T0=0.2209, G2.TF=0.2262; G3.T0=0.1705, G3.TF=0.1756) showing no significant differences (signal test, p>0.05). There was loss of mass, being significant (Student’s-t test p>0.05) for Group G2 (G2.T0=0,3980, G2.TF=0,3843). Adherence of Streptococcus mutans forming colonies was observed (UFC/mg): 7,17 x 104,G1; 3,83 x 104, G2; 2,83 x 104, G3, showing no significant differences among the groups (Kruskal-Wallis test, p>0.05). Conclusion: It was concluded that acidic solutions compromise the surface quality of indirect polymeric matrix, propitiating an irregular structure that compromises the quality of the restoration and favor bacterial plaque formation. Keywords:Composite resin, acidic solutions, surface properties, microbial adherence

Objectives: Dental biofilm can be formed in greater quantities and on rough surfaces. Biofilm maturation has clinical implications because the presence of pathogenic microorganisms. This study verified surface degradation and bacterial adherence to Resilab Master® after immersion in acid solutions. Material and Methods: The specimens (diameter=10 mm ⁄ thickness = 2 mm) were stored in deionized water for 7 days, and divided into immersion groups (n=10): Coca Cola, G1; H2OH lemon refrigerant, G2; phosphoric acid, G3; and citric acid, G4; immersed for 7 days. Mass (g) was analyzed with a digital scale, and Ra roughness (μm) by readouts on specimen surfaces using a roughness meter. Three specimens of the groups were analyzed by SEM(deionized water – control). Five specimens of the groups were introduced into test tubes with Streptococcus mutansand glucose. Results: They were incubated at 37ºC/24h. Results: Increase in roughness (G1.T0=0.2209, G1.TF=0.2262; G2.T0=0.1705, G2.TF=0.1756; G3.T0=0.1848, G3.TF=0.2276; G4.T0=0.1694, G4.TF=0.1905) showing no significant differences (signal test, p>0.05). Loss of mass, being significant (Student’s-t test p>0.05) for Groups G1 (G1.T0=0.3560, G1.TF=0.3535) and G3 (G3.T0=0.3594, G3.TF=0.3532). Adherence of Streptococcus mutansforming colonies was observed on the surface degraded (UFC/mg): 3.83 x 104, G1; 2.83 x 104, G2; 4.67 x 104, G3; 3.67 x 105, G4 showing no significant differences among the groups (Kruskal-Wallis test, p>0.05). Conclusions: The acid solutions caused damage to the material surface with loss of matter, intensifying bacterial colonization. Solutions with the same pH and type of acid, but different compositions, showed no significant differences on indirect polymeric matrix degradation.