Expert consensus on dental caries management / 国际口腔科学杂志·英文版

Dental Caries is a kind of chronic oral disease that greatly threaten human being's health. Though dentists and researchers struggled for decades to combat this oral disease, the incidence and prevalence of dental caries remain quite high. Therefore, improving the disease management is a key issue for the whole population and life cycle management of dental caries. So clinical difficulty assessment system of caries prevention and management is established based on dental caries diagnosis and classification. Dentists should perform oral examination and establish dental records at each visit. When treatment plan is made on the base of caries risk assessment and carious lesion activity, we need to work out patient‑centered and personalized treatment planning to regain oral microecological balance, to control caries progression and to restore the structure and function of the carious teeth. And the follow-up visits are made based on personalized caries management. This expert consensus mainly discusses caries risk assessment, caries treatment difficulty assessment and dental caries treatment plan, which are the most important parts of caries management in the whole life cycle.

Efficacy of immune responses induced by anti-caries DNA vaccine-loaded bacterial ghost in mice / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To develop an anti-caries DNA vaccine-loaded Salmonella typhimurium (St) ghost and enhance the efficacy of immune responses induced by anti-caries DNA vaccine via mucosal route.</p><p><b>METHODS</b>Both pREP4 and PhiX gene E expression plasmids were transformed into StJ357 and then induced with isopropyl β-D-1-thiogalactopyranoside (IPTG). The bacterial ghosts (BG) were collected after wash and loaded with anti-caries DNA vaccine pGJGLU/VAX. Mice were divided into four groups and immunized through the nasal route with pGJGLU/VAX-loaded BG (Group Ghost+pGJGLU/VAX), pVAX1-loaded BG (Group Ghost+pVAX1), pGJGLU/VAX-Bupivacaine complex (Group pGJGLU/VAX) and pVAX1-Bupivacaine complex (Group pVAX1), respectively. Enzyme-linked immunosorbent assay (ELISA) was used to evaluate the immune responses.</p><p><b>RESULTS</b>ELISA results showed that group Ghost+pGJGLU/VAX had significantly higher level of specific anti-GLU SIgA antibody [(0.367 ± 0.086) A/µg] compared with group Ghost+pVAX1 [(0.122 ± 0.077) A/µg], Group pGJGLU/VAX[(0.068 ± 0.068) A/µg] or Group pVAX1[(0.089 ± 0.089) A/µg] (P = 0.028, 0.012 or 0.030, respectively).</p><p><b>CONCLUSIONS</b>St ghost was developed successfully, which enhanced the efficacy of immune responses induced by anti-caries DNA vaccine pGJGLU/VAX via the nasal route.</p>

Optimizing expression and antibody preparation of recombinant Streptococcus mutans surface protein / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The soluble protein recombinant Streptococcus mutans surface protein (rPAc) was expressed in Escherichia coli (E.coli) after the optimization of inducing conditions. The antiserum against rPAc was obtained by immunizing mice with the purified rPAc.</p><p><b>METHODS</b>The soluble expression of rPAc in E. coli was further optimized by means of different culture conditions. Polyclonal antibody was made by immunizing mice with purified rPAc. Western blot and enzyme linked immunosorbent assay (ELISA) were carried out to identify the immunocompetence of the antibody.</p><p><b>RESULTS</b>The highest soluble expression level of rPAc was obtained at Luria-Bertani (LB) medium (pH=7.2) when optical density (OD600nm) was 0.6 after being induced at 30 degrees C for 4 h and the concentration of isopropyl beta-D-1-thigalactopyranoside (IPTG) was 1.0mmol x L(-1). The titer of the mice antiserum against rPAc was about 1:6000 by ELISA analysis, and rPAc could be specifically recognized by Western blot analysis.</p><p><b>CONCLUSION</b>This study proved that rPAc can be effectively expressed as a soluble form in E. coli, and the high specific polyclonal antibody of rPAc was proved to be prepared, which shed light on further research of DNA prime-protein boost inoculation.</p>

The study on specific anti-Streptococcus mutans IgY against dental caries in rats / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of specific anti-streptococcus mutans IgY against streptococcus mutans on dental caries development in rats.</p><p><b>METHODS</b>35 wistar rats were divided into 5 groups: group A received IgY gargle; group B received IgY lyophilized powder; group C received sterilized water as control; group D and E received egg yolk food with or without specific IgY individually. They were all fed with caries-inducing diet 2000#. The number of caries scores was counted by the procedure of Keyes'.</p><p><b>RESULTS</b>There was a significant lower mean of caries scores in groups treated with IgY lyophilized powder and gargle. By treating with egg-yolk food contained specific IgY, the mean of caries scores decreased comparing with no treatment group.</p><p><b>CONCLUSION</b>Local passive immunization with specific anti-streptococcus mutans IgY may be an effective way to prevent the development of dental caries.</p>

DNA vaccine encoding Streptococcus mutans surface protein protected gnotobiotic rats from caries / 中华口腔医学杂志

<p><b>OBJECTIVE</b>Protein of Streptococcus mutans is considered as one of the virulence factors due to its ability to mediate the initial attachment of Streptococcus mutans to tooth surface. In this study, an anticaries DNA vaccine pCIA-P was used to immunize rats. The expression of PAc in different tissues in vivo, specific immune response and protection effects against dental caries were observed.</p><p><b>METHODS</b>Plasmid pCIA-P was injected into rats by two different routs: intramuscular injection (i.m.) and targeted salivary gland immunization (TSG). Immunohistochemistry technique was used to detect the expression of PAc. Gnotobiotic rats were vaccinated with pCIA-P by three different approaches: TSG, intramuscular injection and buccal mucosal injection (i.o.). The specific immune responses were evaluated by ELISA and their anticaries effects were evaluated by Keyes caries scores.</p><p><b>RESULTS</b>PAc was expressed in the sarcoplasm and sarcolemma of muscle fibers and submandibular glands, especially strongly positive in duct regions. The levels of serum specific anti-PAc IgG and salivary specific anti-PAc IgA in TSG immunization and buccal mucosal immunization group were significantly higher than those of other groups. The Keyes caries scores of those two groups were significantly lower than those of other groups.</p><p><b>CONCLUSION</b>The plasmid pCIA-P could provoke specific immune responses as a novel immunogen. Mucosal immunization with pCIA-P appears to be an effective genetic immunization method against dental caries.</p>

The crystallographic properties of the mineral phases of enamel and dentin in normal deciduous and permanent teeth / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the crystallographic properties of the mineral phases of normal enamel and dentin (dental apatite) in deciduous and permanent teeth.</p><p><b>METHODS</b>Three kinds of physical methods including X-ray diffraction (XRD), infrared absorption spectroscope (IR) and electron probe micro-analysis (EPMA) were utilized in this study.</p><p><b>RESULTS</b>Dental apatite was not uniphase, but multiphase, which could be described as carbonate-substituted hydroxyapatite. Compared to dentin apatite, the higher crystallinity and expanded a-axis lattice parameters were found in enamel. Chemical analyses demonstrated that higher concentrations of Mg and CO(3)(2-) were found in dentin than those of enamel. But enamel had higher Cl content.</p><p><b>CONCLUSIONS</b>The differences among enamel and dentin, in terms of lattice parameter and crystallinity may be partially attributed to the incorporation of Mg, CO(3)(2-) and Cl minor elements.</p>

Polymerase chain reaction analysis of the clonality of Porphyromonas gingivalis and collagenase gene / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the genotypic characterization of Porphyromonas gingivalis (Pg) and the heterogeneity of a potential virulence factor-PrtC.</p><p><b>METHODS</b>Arbitrarily primed polymerase chain reaction (AP-PCR) was applied to 80 Pg strains isolated from 24 unrelated Chinese periodontitis patients. PCR reaction was used to detect a fragment of the collagenase gene (PrtC gene). To evaluate the sequence heterogeneity of the Pg PrtC genes, sequence analysis of four PrtC gene of clinical isolates was performed.</p><p><b>RESULTS</b>Random primer OPA-05 and OPA-17 distinguished 7 AP-PCR profiles (I through VII). The majority of the strains belonged to type VII which accounted for 25.8%. A 548bp fragment of PrtC gene was detected from 24 clinical strains. The PCR products were verified by the restriction endonucleases PstI and PvuI. Sequence analysis showed 4 PrtC genes were heterogeneous in their nucleotide composition and differed from reference strain Pg 53977.</p><p><b>CONCLUSIONS</b>The results demonstrated genetic diversity existed among these clinical strains isolated from Chinese periodontitis patients and the PrtC genes are heterogeneous in their nucleotide sequence.</p>

Extract and identify ingredient from Ligustrum Lucidum Ait and study its effect to periodontal pathogen / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To extract the effective ingredient (crystal I) from effective section (saponin) of Ligustrum Lucidum Ait, identify the chemical structure of crystal I, study the effect of crystal I on P. gingivalis, B. forsythus and P. intermedia.</p><p><b>METHODS</b>Isolated crystal I from saponin using the silica gel column chromatograph. Identified crystal I with IR spectra, (1)H-NMR and (13)C-NMR. Measured the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) through micro-liquid dilution. Studied the killing curve of ursolic acid on B. forsythus and P. intermedia.</p><p><b>RESULTS</b>The crystal I was identified as ursolic acid; its MIC and MBC to P. gingivalis, B. forsythus and P. intermedia were 0.740 and 0.295 microg/L respectively. The killing curve indicated that 0.800 microg/L ursolic acid could kill P. intermedia and B. forsythus in 3 and 6 hours respectively.</p><p><b>CONCLUSION</b>Ursolic acid has obvious effect to inhibit periodontal pathogen.</p>

Transforming growth factor beta(1) and bone morphogenetic protein 2 induce the differentiation of odontoblasts in vitro / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effects of transforming growth factor beta(1) (TGF-beta(1)) and bone morphogenetic protein 2 (BMP2) combined with heparin on odontoblast differentiation.</p><p><b>METHODS</b>Trypsin-isolated dental papillae from day 17 mandibular first molar were cultured in semisolid-agar medium for 6d. Recombinant human TGF-beta(1) and BMP2 combined with heparin were added to the medium.</p><p><b>RESULTS</b>TGF-beta(1) and BMP2 combined with heparin induced differentiation of odontoblasts and promoted matrix secretion. Odontoblast differentiation never occurred when TGF-beta(1) or BMP2 were added alone to the medium, whereas an increase in extracellular matrix production was observed.</p><p><b>CONCLUSION</b>These results demonstrate that both TGF-beta(1) and BMP2 stimulate the cytological and functional differentiation of preodontoblasts, and that heparin might play important role as a substrate.</p>

Intranasal immunization against dental caries with plasmid DNA encoding pac gene of Streptococcus mutans in gnotobiotic rats / 中华口腔医学杂志

<p><b>OBJECTIVES</b>To assess the efficacy of plasmid DNA encoding pac gene of Streptococcus mutans (S. mutans) intranasally immunized in gnotobiotic rats and to compare the effect of two different delivery systems.</p><p><b>METHODS</b>Sprague Dawley rats, infected with S. mutans at 20 days of age, were intranasally immunized with plasmid pCIA-P (group A), Dosper-DNA complex (group B), Bupivacaine-DNA complex (group C). Control rats were either immunized with plasmid pCI (group D), distilled water (group E) or immunized intramuscularly (group F). All the rats were boosted 2 weeks later. ELISA determined the antibodies against the vaccines. Keyes caries score was used to evaluate the anti- caries effectiveness of the vaccines at the terminal study.</p><p><b>RESULTS</b>As for the antibody reactions, there were significantly (P < 0.01) differences between rats immunized with DNA vaccine and non-immunized rats. And rats in group B and C had the significantly (P < 0.01) higher level of specific salivary anti-PAc IgA antibodies and rats (group B, C, F) had the significantly (P < 0.01) higher specific serum anti-PAc IgG responses to DNA vaccine. Keyes scores of rats (group B and C) were significantly (P < 0.01) lower than others.</p><p><b>CONCLUSIONS</b>Intranasal immunization with plasmid pCIA-P encoding pac gene successfully reduces the caries and appears to be a promising approach against dental caries. Cationic liposome Dosper and local anesthetic bupivacaine could enhance the efficacy of DNA vaccine.</p>

Construction and cellular expression of GTF-PAc fusion anti-caries DNA vaccine / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To construct a fusion anti-caries DNA vaccine pGLUA-P carrying GLU fragment from gtfB gene of Streptococcus mutans GS-5 and A-P fragment including the A region and P region of PAc protein from a DNA anti-caries vaccine pCIA-P, and to investigate its expression in prokaryotic and eukaryotic cells.</p><p><b>METHODS</b>The sequence of GLU fragment in pGLU plasmid was testified by DNA sequencing. The fusion anti-caries DNA vaccine was constructed by ligating A-P fragment from pCIA-P to pGLU. The expression of GLUA-P fusion protein in E. coli BL21 (DE3) was induced by IPTG and checked by SDS-PAGE electrophoresis. pGLUA-P was transfected in vitro to cultured rat primary muscle cells by cation liposome Dosper, and immunohistochemical method was used to test the expression of GLUA-P fusion protein in cells.</p><p><b>RESULTS</b>GLU sequence was identical with relative sequence of GTF-I (GS-5 strain) in Gene Bank. Recombinant eukaryotic expression plasmid pGLUA-P was confirmed to have both GLU and A-P fragment. After pGLUA-P was transferred into E. coli (DE3), it could express a new 115 000 protein by the induce of IPTG. Specific brown products could be found in the cytoplasm of cultured rat primary muscle cells transfected by pGLUA-P.</p><p><b>CONCLUSIONS</b>Fusion anti-caries DNA vaccine pGLUA-P is successfully constructed and confirmed by sequencing and enzymes digestion. Fusion GLUA-P protein can be correctly expressed in prokaryotic and eukaryotic cells.</p>

Effect of 400g/L chlorhexidine varnish on occlusal and approximal dental plaque / 实用口腔医学杂志

Objective:To compare the antibiotic effects of 400 g/L chlorhexidine(CHX) varnish on different teeth surfaces. Methods: 400 g/L chlorhexidine(CHX) varnish was applied onto the left mandibula r first molar once in 5 young volunteers (group 1) or twice with a interval of I week in another 5 (group 2). The right mandibular first molar was served as th e control.Plaque samples from fissure or approximal surface were taken for Str eptococci mutans (S.mutans) detection with routine bacteriologic procedure onc e a week for 16 weeks. Results: In group 1 S.mutans in the plaque in fissue was significantly suppressed from 1 to 4 weeks after the v arnish application (P

Endodontic microleakage following lateral condensation or vertical condensation technique / 实用口腔医学杂志

0.05) after condensation. The difference of leakage between A and B, B and D groups was significant from 20 and 15 days on. The glucose concentration in group A and B was higher than that in group C and D during the corresponding observation period and using the corresponding sealer materia.AH Plus resulted in less leakage than Pulp Canal Sealer EWT did when using lateral condensation technique and two sealer performed the same when using vertical condensation method.Conclusions:The sealing ability of vertical condensation technique is better than that of lateral.

Effects of Platycodon grandiflorum,Glycyrrhiza uralensis Fisch or the compound of both on the growth of oral pathogens in vitro / 实用口腔医学杂志

Objective: To examine effects of Platycodon grandiflorum (JG), Glycyrrhiza uralensis Fisch (GC) or the compound of JG with GC on the growth of cariogenic and periodontopathic bacteria in vitro . Methods: JG,GC and the compound were extracted with ?=65% ethanol respectively. The minimal inhibitory concentration(MIC)and minimal bactericidal concentration (MBC) of JG, GC or compound against S.mutans MT818, S. sobrinus 6715, P.gingivalis 381 and B.forsythus 43037 were measured by drug sensetivity test.Results: JG showed no effect on the growth of oral pathogens tested;GC inhibited S.mutans MT 8418 and S.sobrinus 6715 with MIC of 3.91 mg/ml.The compound inhibited the microorganisms with the MIC of 1.96 mg/ml against S.mutans MT8148 or S.sobrinus 6715, 3.91 mg/ml against P.gingivalis 381, 7.81 mg/ml against B.forsythus 43037 respectively.Conclusion: The compound of JG and GC has stronger inhibition and bactericidal effects on oral pathogens than the single medicine.