title: The impact of three strains of oral bacteria on the surface and mechanical properties of a dental resin material.
abstract: The purpose of this study was to determine if three strains of bacteria could impact the mechanical or surface properties of a dental resin material. Resin material specimens were incubated at 37°C in sterile saline, tryptic soy broth supplemented with sucrose (TSBS), or TSBS inoculated with Streptococcus mutans, Streptococcus gordonii, or Streptococcus sanguis. The specimens were subjected to Fourier transform infrared spectroscopy before and after incubation. The flexural strength test was performed once a week for 6 weeks. Microhardness and scanning electron microscopy (SEM) was performed on specimens at 1 and 6 weeks. Differences in the area under the carbonyl peak were statistically significant for the specimens incubated in the media inoculated with either S. mutans or S. gordonii. To determine why S. sanguis did not produce changes as the other bacteria did, triethylene glycol dimethacrylate, methacrylic acid, and triethylene glycol were added to bacterial cultures at increasing concentrations. Both methacrylic acid and triethylene glycol reduced the number of colony-forming units of S. sanguis. Specimens incubated in TSBS, saline or in culture with S. sanguis demonstrated a decrease in peak stress in week 1 of the flexure strength test. SEM demonstrated that surface topology changed for those specimens incubated in culture with S. mutans or S. gordonii. The changes in surface topology demonstrated here could contribute to the secondary caries and changes in esthetic properties seen clinically with the use of resin materials in dental restorations.
authors: Department of Oral Biology, Indiana University School of Dentistry, 1121 West Michigan Street, Indianapolis, IN 46202, USA. kagregso@iupui.edu
authors: Karen S
authors: KS
authors: Gregson
authors: Han
authors: H
authors: Shih
authors: Richard L
authors: RL
authors: Gregory
mesh_terms: D058491:Bacterial Load; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002364:Caseins / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D003470:Culture Media / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D006244:Hardness; D006801:Humans; D008422:Materials Testing; D055595:Mechanical Phenomena; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D009055:Mouth / Q000382:microbiology*; D018583:Pliability; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011492:Protein Hydrolysates / Q000737:chemistry; D012965:Sodium Chloride / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013291:Streptococcus / Q000502:physiology*; D054773:Streptococcus gordonii / Q000502:physiology; D013295:Streptococcus mutans / Q000502:physiology; D013298:Streptococcus sanguis / Q000502:physiology; D013314:Stress, Mechanical; D013395:Sucrose / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
chemical_list: D002364:Caseins; D003188:Composite Resins; D003470:Culture Media; D003764:Dental Materials; D008689:Methacrylates; D011109:Polymethacrylic Acids; D011492:Protein Hydrolysates; C026375:trypticase-soy broth; C020946:triethylene glycol dimethacrylate; C008384:methacrylic acid; C028914:triethylene glycol; D011092:Polyethylene Glycols; D012965:Sodium Chloride; D017438:Bisphenol A-Glycidyl Methacrylate; D013395:Sucrose