Objective:The purpose of this study was to investigate the effects of Class V cavities sealed with two dental materials, com- pomer and light-cured glass ionomer cement (LGIC), and how the design of cavities affects restoration effects.Methods:A total of 100 permanent posterior teeth were selected for this experiment, and five types of cavities were prepared buccally. The cavities were restored with the compomer Dyract and the LGIC Vitremer. After50 times of thermocycles, all the specimenswere immersed in 1% solution of methylene blue dye, and then sections of the restorations were evaluated under an Olympus stereomicroscope. Two of the specimens were observed under scanning electronic microscope (SEM).Results:Microleakage happened more fre- quently at the gingival site than at the occlusal site. At the enamel site, the cavity design had little influence on microleakage for these two materials; but at the gingival site, Type e leakage happened more frequently than Type a/b for the compomer, and the incidence of Type c/d leakage was less than Type a/b for the LGIC.Conclusion:The restoration effectof compomerDyractis bet- ter than that of LGIC.

Objective:The purpose of this study was to investigate the inhibitory effect of interleukin-10 (IL-10) on the periodontal inflammatory reaction.Methods:Cell culture and ELISAwere used to evaluate the concentration of interleukin-1B(IL-1B) in the supernatant, and MTT was used to examine the proliferation response of human gingival fibroblasts to lipopolysaccharides and IL-10.Results:IL-1Bsecreted by human gingival fibroblastswas induced by lipopolysaccharides in a dose-dependentmanner and reached the highest level in 6 h. IL-1Bwas inhibited by IL-10, and the optimal inhibitory concentration of latter was 10 ng/ml. The inhibitory effect of IL-10 in the optimal concentration to IL-1Breached the maximum in 24 h. Further the proliferation of hu- man gingival fibroblasts was also induced by lipopolysaccharides, but not affected by IL-10.Conclusion:IL-10 is a cytokine that can inhibit periodontal inflammatory reaction.

Objective:The study aimed at investigating the effects of areca nut extracts on the levels of ICAM-1 expressed by the oral fi- broblasts.Methods:The fibroblasts were obtained from normal buccal mucosa and buccal mucosal with submucous fibrosis and cultured in vitro. The levels of ICAM-1 expressed by fibroblasts incubated with/without ANE in the presence of 10% fetal calf serum in the mixed gas of 5% CO2and air at37efor48 h, were monitored using cell-based ELSA.Results:The fibroblasts ob- tained frommucosalwith oral submucous fibrosis expressed ICAM-1 at a high level. ANE increased the expression levels of ICAM- 1 in both fibroblasts obtained from normal and abnormal mucosa.Conclusion:The high expression levels of ICAM-1 in the fibrob- lasts of oral submucousfibrosis and ANE stimulated the expression of ICAM-1, whichmay be one of the importantmechanismswhy lymphocytes become localized and retained atthe side of connective tissue during inflammation and lead to activation of fibro

Objective:The present study investigated the expression level of bone morphogenetic proteins (BMP) during the movementof experimental orthodontic teeth irradiatedwith low-power laser, in orderto explore the effectof local irradiationwith low-power laser on the bone remodeling during orthodontic tooth movement.Methods:Rabbits were given local irradiation with low-power laser during the movementof their teeth inducedwith the experimental orthodontic appliance. BMP in periodontal tissue of the orthodon- tic teeth was examined quantitatively using immunohistochemical stain and image analysis system.Results:The expression level of BMP increased in a higher level in the early stage and lasted for a long time in the compression and tension area on the side irradi- ated with low-power laser than on the side without laser irradiation.Conclusion:During the movement of orthodontic teeth, local irradiationwith low-power could increase the expression of BMP. It suggests that the irradiationwith low-power laser could promote bone remodeling and accelerate the movement of orthodontic teeth.

Objective:The purposes of the present animal experiment were to investigate the histogenesis of odontogenic keratocyst. Methods:A total of 17.5-day-old C3Hmouse embryos were removed from pregnant females and placed in 2% bovine serum in Hanks solution. Under a dissecting microscope, the mandibular first molar tooth germs with the dental lamina and oral epithelia were cut from these embryos. The following 3 kinds of graftswere prepared, including recombinantof the dental lamina and dental papilla, recombinant of the oral epithelium and dental papilla, and tooth germ. Three-month-old syngenic male mice were anaes- thetized by intraperitoneal injection of pentobarbital sodium and these grafts were transplanted under the left renal subcapsular spaces of the mice at the rate of one graft per capita. The graftswere harvested at times ranging from 1 to 24 weeks andwere fixed in 10% neutral buffer formalin and demineralized in 5% formic acid at4efor12 h. The specimenswere processed forhistologi- cal examination. Serial sections were made, stained with hematoxylin and eosin, examined using a light microscope.Results: Three kinds of graftsgrewinto cysts lined by parakeralinized ororthokeratinized stratified squamous epithelia. The histopathological features of these cysts were the similar to those seen in the odontogenic keratocyst of human. Of these 58 cases of grafts, kerato- cyst-like lesions were formed in 41 cases and, dental tissue formation were found in 45 cases.Conclusion:These results suggest that the dental lamina, the oral epithelium and external enamel epithelium of enamel organ are the sources of the odontogenic kera- tocyst. The dental lamina and the oral epithelium, when recombinantwith the dental papilla, have compensatory potential of dental tissue formation.

Objective:The purpose of this studywas to detect differentgenotypes ofPorphyromonas gingivalis (P.gingivalis)in subgin- gival plaque samples from patients with chronic periodontitis.Methods:The conventional culture method was used to isolate P. gingivalisfrom 127 subgingival plaque samples of 66 patients with chronic periodontitis. Coamplification of polymerase chain reaction was performed to detect 16SrDNA gene, the collagenase gene (prtC) and fibril gene (fimA) ofP. gingivalisfrom these clinical samples. Parts of the PCR products were TA cloned and then sequenced.Results:The positive rates ofP. gingivalis 16SrDNA, prtC and fimA gene coamplification by PCR in subgingival plaque sampleswere 9814%. PCRwere much more sensi- tive compared with the traditional method for detection ofP. gingivalis (P<0101). Each of the 18 (3010%) patientswas iso- lated two different genotypes ofP. gingivalisatdifferenttooth sites. Compared our sequence resultswith the published nucleotides sequences in Genbank, the homology of PCR products ofP. gingivalis16SrDNA, prtC and fimA gene were from 98162% to 100%.Conclusion:The PCRassay developed in this studywere sensitive and specific. Itis suitable for clinical rapid identification ofP. gingivalisinfection. Some of the patients had different genotypes ofP. gingivalisinfection at different tooth sites which suggests thatone individual may be infectedwith 2 ormore strains ofP. gingivaliswith differentgenotypes that are originated from various contagious sources.

Objective:This study aimed at investigatingwhetherPEGF-BB and PDGF-RBBwere involved in the pathogenesis of oral sub- mucous fibrosis.Methods:Immunoelectronmicroscopywas used for the study of the ultrastructural localization of PDGF-BB and re- ceptors of PDGF-RBBin 6 cases of specimens of oral submucous fibrosis. Each specimen was divided into two parts, consisting of one part for HE staining for pathological staging and the other partfor transmission electronic microscopic observation.Results:Im- munoreactive products of PDGF-BB and its receptorsmainly existed in the cellularplasm of epithelial cells, fibroblasts and vascular endothelial cells, with enlargement of acanthoid cells, swollen mitochondria and abnormal ridges. Immunoreactive products were found on the membrane of epithelial cells, aswell as in the mitochondria, rough endoplasmic reticula and on the membrane of the fibroblasts. Immunoreactive products of PDGF-RBBmainly existed in the rough endoplasmic reticula of fibroblasts and in the cell membrane of acanthoid cells, and also could be found sometimes in the rough endoplasmic reticula of vascular endothelial cells. No immunoreactive productwas found in the normal oral mucous membrane.Conclusion:The findings suggest that PDGF-BB and PDGF-RBBmight play an important role in the pathophysiological process of oral submucous fibrosis.

Objective:The purpose of this study was to quantitatively evaluate the demineralization of the caries-vulnerable sites of first permanentmolars, and identify the most caries-susceptible site in caries-active children.Methods:88 caries-active children (dmft\5) were selected in this study, inwhich 42 children are girls and 46 children are boys. Demineralization of central fossa, lingual groove of the bilateral maxillary first permanentmolars, and the central fossa and buccal groove of the bilateral mandibular first permanent molars were evaluated using laser fluorescence system KaVo DIAGNOdent (Germany). Data were processed using software STATA 510.Results:All the tested siteswere at the initial stage of enamel caries. There was no significant difference of demineralization between the same sites bilaterally (P>0105), or between different genders (P>0105). The central fossa of mandibular first permanentmolar demonstrated significantly higher demineralization than other sites of first permanentmolars (P< 0101). The demineralization of the maxillary central fossa was more severe than that of lingual grooves (P<0105).Conclusion: The central fossa of first mandibular molar is the most important site for caries prevention in children. KaVo DIAGNOdent can be used for early incipient groove and fissure caries detection and monitoring in children.

Objective:The aim of this study was to investigate the features of discs of temporomandibular joints (TMJs), during the joint was in the closing and opening positions.Methods:A total of 9 male university students, 21~23 years old, withoutTMJD symp- tomswere selected for this study, and their bilateral TMJs were examined separately with Siemens 63-SP4000 super conductive MRI system (Germany). The parameters of MRI were 10 cm surface coil, proton-weighted, oblique sagittal section with 3 mm thick. Totally 166 imagineswere obtained including closing and opening positions. Both the area and circle length of the disc sec- tions were measured with the electronic ruler.Results:The disc on the oblique section showed a narrowimagine in the closing po- sition, while a dumbbell-shape in the opening position. The shape of the disc demonstrated larger in the opening position than that in the closing position (P<0.01). The circle length of the disc in the above positions didn.t showed significant difference (P> 0.05).Conclusion:The shape of the TMJ disc in normal subjects changed a lot in the oblique sagittal section from closing to opening positions, which might be related with the internal pressure changes between these two positions.

Objective:The purpose of this study was to evaluate the clinical effects of pendulum appliance on molar distalization.Meth- ods:Ten cases of patients were selected for this study, and whose molars were moved distally with the pendulum appliance. The models of patients before and after treatmentwere analyzed. The distance of moved molars and occlusion of each patientwere ex- amined.Results:The molarwas moved distally with a speed of 1.7 mm per month. The width between molars and over bite was declined 0.9 mm and 1.5 mm respectively. No changeswere found in over jet.Conclusion:The clinic effects of pendulum appli- ance are obvious. It is suitable for adult patients in which the second molars have erupted, but not for patientswith high angles.

Objective:This study was to evaluate and compare the clinical effects of suction drainage and decompression on the treatment of odontogenic keratocysts (OKCs).Methods:Twenty cases of patients were divided into two groups, including 10 in the experi- ment group whowere treated with suction drainage (SG) and 10 in the control group whowere treated with decompression (DG). Clinical symptoms, radiographic findings and the thickness of newbone in these two groupswere evaluated and compared.Results: Significant differences of average decrease of cyst size between these two groups were observed two/six months after the therapy (P<0101). The average thickness of new bone formed around the keratocysts in the experimental group was much greater than that in the control group two/sixmonths after the treatment (P<0105).Conclusion:The method of suction drainage in the treat- ment of OKCs is better than decompression, especialy, which can eliminate the deformity of jaw bone completely. Therefore, the idea treatment process for large odontogenic keratocysts may be combining suction drainage and curettage, which is reliable and predictable.

Objective:The aim of this study was to investigate mother-to-child transmission ofMutans streptococciin Shenyang area of China.Methods:Saliva samples of 16 mothers and their children were collected and cultured on selective medium forMutans streptococci. Arbitrarily primed polymerase chain reactions (AP-PCR) with randomly chosen primers were performed to genotype these isolates.Results:The PCR results demonstrated thatMutans streptococciin 5412% of the mother/child pairswere the same in genotypes. Similargenotypes inmothers and childrenwere found significantly more frequently inmotherswho had more than one genotype. Significant correlation was found in colony forming units (CFU) between mothers and their children.Conclusion:This suggests thatMutans streptococcicould be transmitted frommothers to their children. Significant correlationwas found between the number of genotypes ofMutans streptococciin mothers and the transmission of this group of streptococci from mothers to their chil- dren.

Objective:The purpose of this studywas to evaluate the effects of the pulsed Nd:YAG laserirradiation in root canals on tem- perature changes on the root surface in vitro and optimize the parameters of laser irradiation in root canal treatment.Methods:A total of 108 extracted single-root human teeth were divided into A, B and C groups, after the preparation of root canals and re- moval of their crowns. GroupAwas evaluated the surface temperature changes of differentteeth irradiatedwith the same outputen- ergy. The teeth inGroup B and Cwere irradiated respectivelywith the frequencies of 15 Hz and 20 Hz, and 7 differentoutput en- ergy, and the inner root canal surface inGroup Bwas coatedwith a layerof ink, whichworked as the initiator.Results:The tooth surface temperature of the mandibular incisor increased more obviously than that of the maxillary incisor, canine and premolar, during root canal irradiation treatment (P<0101). Significant difference was shown on the temperature elevation when the teeth were irradiated with 2W or higher output power (P<0101). Temperature increased significantly higher in the teeth with initiator than thatwithout it (P<0101). With the same parameters of output energy, the surface temperature demonstrated higher on the apical partof the root canal than thatin the middle.Conclusion:There is significantly positive correlation between the temperature elevation on the root surface and the average output power and frequency of the pulsed Nd:YAG laserirradiation in the root canal. The shape of tooth, initiator and different parts of the root may also play important roles in the temperature changes of the tooth surface. This study may help optimize the parameters of clinical laser irradiation treatment.

Objective:The purpose of this study was to evaluate the effects of activator and FRⅡappliances on growing children with ClassⅡdivision 1 malocclusion.Methods:The material consisted of pre- and post-treatmentmodels and cephalograms of 16 boys and 18 girls. 12 childrenwere treatedwith activators, and 22 were treatedwith FRⅡappliances.Results:Both activator and FR Ⅱappliances can change ClassⅡrelationship to Class I, and significantly reduced ANB angle to a normal range. FRⅡappli- ance statistically increased the dental archwidth of the maxillary, and there was no statistically significant difference between these two groups in changing basal archwidth. The upperincisorswere retracted muchmore in the groups of FRⅡappliance, the axial inclination of the lower incisors was controlled more efficiently in the activator group.Conclusion:Both the activator and the FR Ⅱappliance can correct the ClassⅡmalocclusions efficiently. Selecting correct appliance is very important in the clinical treat- ment.

Objective:The purpose of this investigation was to study the effects of replication-defective recombinant adenovirus-mediated cytosine deaminase (AdCMVCD) /5-fluorocytosine (5-FC) suicide gene system on tongue carcinoma cells.Methods:AdCMVCD was propagated in 293 tongue carcinoma cells, purified by cesium chloride gradient and titrated using tissue culture infectious dos- es-50 (TCID-50). Transmission electron microscope was used to observe the adenovirus transferred into tongue carcinoma cells (Tca8113 cell line), and reverse transcription polymerase chain reaction (RT-PCR) was performed to detect the expression of CD after infection of Tca8113 cells. The killing effects and bystander effects of AdCMVCD/5-FC system on tongue carcinoma cells were evaluated using MTTassay. The changes of cell cycles after treated with AdCMVCD/5-FC system were monitored with the flow cytometry (FCM).Results:The titration of adenovirus (AdCMVCD) was 613@109/ml plaque forming units (PFUs). Under the transmission electron microscope, the adenoviral particles were found in the nucleus of tongue carcinoma cells. The recombi- nant adenovirus expressed CD after infection of Tca8113 cells in vitro. AdCMVCD/5-FC had strong killing-effects on Tca8113 cells, and these effectswere 5-FC dose-dependent. The maximum killing efficacywas 97%. The bystander effectof this system in Tca8113 cells was good. 58% of cells were killed only when 1215% of cells were infected with AdCMVCD. Compared with the control groups,the cell treated by the AdCMVCD/5-FC accumulated in the S phase of the cell cycle (P<01001) and dropped to zero in the G2+Mphase (P<01001) and didnct change in the G1/G0phase (P>0105).Conclusion:The killing effects and the bystander effects ofAdCMVCD/5-FC system on tongue carcinoma cells are satisfying, and the AdCMVCD/5-FC system targeted on tongue carcinoma cells in the S phase.

Objective:The purpose of this study was to evaluate the safety and therapy effects of super-high molecular weight poly-DL- lactic acid (PDLLA) internal fracture-fixing system on the treatment of mandible fracture in dogs.Methods:The authors treated dogscmandible fracture with super-high molecularweight polylactic acid internal fracture-fixing system and observed the activity of these dogs. In 1, 3, 6, 12 months after the operation, the authors took the specimens out from dogs and evaluated with anatomi- cal, pathological and radiographic methods.Results:The therapeutic effects of super-high molecularweight PDLLA internal frac- ture-fixing system are similarwith that of stainless steel internal fracture-fixing systems.Conclusion:Super-high molecular weight PDLLA internal fracture-fixing system can be used in the treatment of mandible fracture.

Objective:The aim of this experimentwas to study the characterof degradation of super-highmolecularweight poly-DL-lactic acid (PDLLA) internal fracture-fixing system.Methods:The fracture mandible of dogswas fixed with super-high molecularweight PDLLA internal fracture-fixing system. In 1, 3, 6, 12 months afterthe operation, the materialswere taken outfrom dogs, and the palateswere observed using the scanning electron microscopy.Results:The surface of super-high molecular weight PDLLA was coarse. In 1 month after the operation, there were much chaps and grains on the surface of PDLLA. In 3 months after the opera- tion, there were much deeper grooves. In 6 months after the operation, only some scraggly accumulation was seen.Conclusion: Super-high molecularweightPDLLA can degrade on the surface in the beginning, and then the material begins to degrade deeply. The speed of degradation matches with the speed of fracture healing. Itwill help to avoid stress-protecting effect.

Objective:The aim of this study was to investigate the effect of modified polyhydroxybutyrate membranes and polyhydroxybu- tyrate membranes (PHBm) on guided bone regeneration of fresh extract tooth sockets.Methods:The extract tooth socketswere es- tablished by extracted two premolars in each quadrant of a dog. The tooth sockets were covered with the modified PHBm, PHBm and without covering. The dogswere sacrificed in 1,2,3,6 months after surgery. Visual observation, radiography, SPECT, histo- logical inspection and tetracycline measurementwere carried out to evaluate the effects of these twomaterials on preserving alveolar ridge.Results:The results indicated that modified PHBm and PHBm improved the restoration of the socket and preserved the con- tour and height of the alveolar ridges.Conclusion:Modified PHBm and PHBm can be used in protecting extract tooth sockets and preserve alveolar ridges.

Objective:The aim of this study was to study cytotoxic effects of cucurbitacin BE polylactic acid nanoparticles (CuBE-PLA- NP) on human oral squamous carcinoma cell lines Tca8113 (tongue carcinoma) and BcaCD885 (buccal carcinoma).Methods: The chemosensitivity of Tca8113 and BcaCD885 to CuBE-PLA-NP and CuBEwas tested usingMTTassay, the inhibitory rate and 50% inhibition concentrations values (IC-50) of these two drugs against these two cancer cell lineswere evaluated in 1,2,3,4,5, 6,7 and 8 days with different concentrations.Results:Both CuBE-PLA-NP and CuBE showed very high anti-cancer effects on Tca8113 and BcaCD855, and the anticancer efficacy of these two drugswas dose- and time-dependent.Conclusion:The effects of CuBE-PLA-NP on lymph nodes of metastatic cancer cells were higher than that of CuBE.