OBJECTIVETo examine the role of lactoferrin (LF) on Toll like receptor 4 (TLR4) stimulated by lipopolysaccharide (LPS) in human periodontal ligament cells (hPDLCs).

METHODSPrimary hPDLCs were cultured by tissue block enzymolytic method. Cells obtained from four passages were identified and used in this experiment. Cells without stimulation served as the controls and cells treated with LPS (0.1 microg x mL(-1)) comprised the LPS group. The LPS + LF group was pretreated with LPS (0.1 microg x mL(-1)) for 2 h, and then treated with LF (10 microg x mL(-1)). Four hours after LF stimulation, the mRNA expression levels of TLR4 were examined by real-time quantitative polymerase chain reaction (RT-PCR). The protein expression of TLR4 was observed by cell immunofluorescence staining after LF stimulation of 24 hours.

RESULTSTLR4 mRNA expression in the LPS + LF group was significantly more decreased than that in the LPS group (P < 0.05), but exhibited no difference with that in the control group (P > 0.05). Cell immunofluorescence staining showed that the protein expression of TLR4 in the LPS + LF group was significantly more decreased than that in the LPS group (P < 0.05), but exhibited no difference with that in the control group (P > 0.05).

CONCLUSIONLF can decrease the expression of TLR4 stimulated by LPS in hPDLCs, thus presenting potential application for controlling the TLR4 immune pathway of periodontitis.

Down-Regulation ; Humans ; Lactoferrin ; Lipopolysaccharides ; Periodontal Ligament ; Periodontitis ; Toll-Like Receptor 4

OBJECTIVETo investigate the effect of exogenous c-di-GMP in preventing dental caries formation in SD rats.

METHODSTwenty-day-old SD rats with dental caries induced by S. Mutans infection were randomly divided into 3 groups for treatment with dental application of exogenous c-di-GMP, NaF solution or 0.9% NaCl, and changes in the bacterial number and scores of dental caries following the treatments were recorded.

RESULTSCompared with 0.9% NaCl treatment, exogenous c-di-GMP treatment significantly lowered the scores of dental caries on the occlusal surface and smooth surface (P<0.05) but produced no obvious effect on the number of bacterial plagues (P>0.05).

CONCLUSIONExogenous c-di-GMP can be a novel agent for prevention and treatment of tooth decay.

Animals ; Cyclic GMP ; analogs & derivatives ; therapeutic use ; Dental Caries ; microbiology ; prevention & control ; Disease Models, Animal ; Female ; Rats ; Streptococcus mutans

OBJECTIVETo evaluate the effects of sandblasting and different orthodontic adhesives on shear bond strength between zirconia and enamel.

METHODSZirconia ceramic samples were designed and manufactured for 40 extracted human maxillary first premolars with CAD/CAM system. The samples were randomized into 4 groups for surface treatment with sandblasting and non-treated with adhesives of 3M Transbond XT or Jingjin dental enamel bonding resin. After 24 h of bonded fixation, the shear bond strengths were measured by universal mechanical testing machine and analyzed with factorial variance analysis.

RESULTSThe shear bond strength was significantly higher in sandblasting group than in untreated group (P<0.05) and comparable between the two groups with the adhesives of Transbond XT and dental enamel bonding resin (P>0.05).

CONCLUSIONThe shear bond strength between zirconia and enamel is sufficient after sandblasting regardless of the application of either adhesive.

Adhesives ; Adolescent ; Adult ; Computer-Aided Design ; Dental Enamel ; Humans ; In Vitro Techniques ; Molar ; Resins, Synthetic ; Shear Strength ; Surface Properties ; Young Adult ; Zirconium

In stomatology, root canal therapy is a commonly used and effective treatment for dental pulp diseases and periapical diseases. However, pain may occur during or after treatment and may severely affect patients. This article aimed to analyze the mechanism and cause of pain during root canal therapy, which may reduce or relieve pain.
Humans ; Pain ; Periapical Diseases ; Root Canal Therapy