Antimicrobial effects of a bioactive glass combined with fluoride or triclosan on Streptococcus mutans biofilm.

OBJECTIVE: The objective of this study was to investigate the antibacterial effects on a cariogenic biofilm of a bioactive glass (BAG) combined with either sodium fluoride (NaF) or triclosan (TCS). DESIGN: According to minimal bactericidal concentrations, 37.5mg/ml of BAG, 4.69 mg/ml of NaF, and 15.53 µg/ml of TCS solutions were prepared. When used alone, the three antimicrobial solutions were increased to double-dosage strength (2 MBC). The study contained the following experimental groups: group 1, BAG (2 MBC); group 2, NaF (2 MBC); group 3, TCS (2 MBC); group 4, BAG+NaF; group 5, BAG+TCS; group 6, control (saline). Streptococcus mutans biofilm was cultured with 0.1% sucrose anaerobically on 66 sterilized coverslips (1 × 1 cm(2)) for 24h uninterrupted. After 10 min of exposure to the experimental groups, the microbial kinetics, morphology, and viability of the S. mutans biofilms were assessed by evaluation of colony-forming units (CFUs), scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM). RESULTS: BAG (2 MBC) used alone showed significantly stronger antibacterial effects than the other two antimicrobials used alone. The combination groups also displayed the same or greater biofilm inactivation effects as BAG (2 MBC) in the plate count test. SEM showed smaller stacks (towers) and fewer surrounding bacteria in groups BAG (2 MBC), BAG+NaF, and BAG+TCS. Confocal microscopy also determined higher live/dead ratios in groups NaF (2 MBC), TCS (2 MBC), and control than in groups BAG (2 MBC), BAG+NaF, and BAG+TCS. CONCLUSIONS: The combinations of BAG with either NaF or TCS enhanced the inactivation effects of BAG (2 MBC) on S. mutans biofilm, and these findings should be further investigated clinically for the control of dental biofilms.

Histologic investigation of gingival epithelium implantation and the nonincision placement of miniscrews.

PURPOSE: This study investigated whether the nonincision placement of miniscrews could lead to ectopic implantation of epithelium at the bone-implant interface and, if so, whether the epithelial cells could survive. The fate of grafted epithelial cells was also investigated. MATERIALS AND METHODS: Ten healthy male beagle dogs were included in the study and were divided into three groups. Group 1 dogs (n = 3) were implanted with miniscrews without any other procedures. In group 2, epithelial cells were collected, infected by adeno-associated virus-2 containing green fluorescent protein (GFP), and injected into pilot holes drilled before miniscrew implantation in three dogs, and one dog was injected with epithelial cells as a negative control. In group 3, tiny gingival tissue pieces were injected into pilot holes drilled before miniscrew implantation. In group 1, hematoxylin-eosin and fluorescent immunohistochemical (IHC) staining of cytokeratin were performed on both undecalcified and decalcified slices. In groups 2 and 3, IHC staining of cytokeratin and apoptotic testing were performed. RESULTS: No ectopically implanted epithelial cells were found at the bone-implant interface of the miniscrews in group 1. In group 2, fluorescence emitted by cytokeratin antibody and by GFP was observed in specimens at 0 days, had decreased by 3 days, and had disappeared by 7 days. In group 3, areas of fluorescent cytokeratin-positive tissues were much smaller at 7 days than at 0 days, and none were found at 28 days. In groups 2 and 3, there were many apoptotic epithelial cells at the bone-implant interface at 3 days and 7 days, respectively. CONCLUSION: There was little possibility of implantation of epithelium into alveolar bone though placement of miniscrews with a nonincision procedure. Furthermore, even when epithelial cells or tissue was ectopically implanted, it was soon cleared through an apoptotic process.

Differences in facial profile and dental esthetic perceptions between young adults and orthodontists.

INTRODUCTION: The principal aim of this study was to investigate differences in perception of soft-tissue facial profiles and dental esthetics between young Chinese adults and orthodontists. METHODS: Eight hundred ninety-two subjects (444 male, 448 female), ages 16 to 24 years, chose 1 image from among 5 profile silhouettes and from among 10 ranked color photographs of the aesthetic component (AC) of the index of orthodontic treatment need that most closely resembled their own profile and dental esthetic appearance, respectively. A panel of 20 orthodontists then independently repeated the same image selection process. Each subject also completed the Eysenck personality questionnaire for psychoticism. We used the Mann-Whitney U test and the Spearman rank correlation test, with statistical significance set at α = 0.05. RESULTS: Only 37.0% of subjects had straight profiles by objective orthodontic assessment, but 85.0% chose straight profiles by subjective self-perception. About 17.5%, mainly females, chose the mild convex as the ideal profile. Only 2.5% of the subjects were ranked 1 on the AC by orthodontists, but 43.6% chose 1, or ideal, by self-perception. Male subjects scored significantly higher than did female subjects for self-perceived facial profiles (more protruded chins) and for the AC (more attractive dental appearance). Subjects with high psychoticism T scores (>50) scored significantly lower for self-perceived facial profiles (more retruded chins) and on the AC (less attractive dental appearance). CONCLUSIONS: Young Chinese adults perceived their facial profiles and dental appearances to be significantly more straight and attractive, respectively, than did the orthodontists. A significant proportion of the young adults, mainly women, preferred a mild convex facial profile. High psychoticism scores might significantly affect the self-perception of orthodontic treatment needs.

Effect of 3 vertical facial patterns on alveolar bone quality at selected miniscrew implant sites.

OBJECTIVE: To evaluate dental alveolar bone quality among young healthy Chinese adults having 3 different vertical patterns. MATERIALS AND METHODS: Three-dimensional cone-beam computed tomography images of 101 subjects (15 low-angle, 48 average-angle, and 38 high-angle) were reconstructed. Facial alveolar cortical bone thicknesses and cortical and cancellous bone densities at 4 selected miniscrew implant sites in both arches, together with cancellous bone densities of third cervical vertebrae, were measured. Bone qualities were compared among the 3 vertical pattern groups. RESULTS: The cortical bone thicknesses at mandibular 5-6 and 6-7 and the cortical and cancellous bone densities at maxillary and mandibular 5-6 and 6-7 were generally greater in the low-angle than in the other 2 groups. There was no similar consistent vertical pattern apparent for bone quality at the 1-1 and 1-2 sites. No significant differences in bone densities for third cervical vertebrae were found among the 3 groups. CONCLUSION: Careful selection of suitable implantation sites and sizes of the miniscrews used should be made to reduce the possible occurrence of implant loosening in patients with average-angle and high-angle vertical facial patterns in particular.

Bilateral maxillary fused second and third molars: a rare occurrence.

This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months.

Apical root resorption in maxillary incisors when employing micro-implant and J-hook headgear anchorage: a 4-month radiographic study.

This study evaluated, over a 4-month study period, the amount of apical root resorption occurring in maxillary central incisors following their retraction when employing either micro-implant or J-hook headgear anchorage. The prospective randomised clinical trial was conducted in Orthodontic Clinic, College of Stomatology, China from 2008-2009. Subjects are patients requiring fixed appliances on waiting list (n=20). In female Han Chinese patients aged from 16-26 years, standardized periapical radiographs from 10 randomly assigned patients with maxillary protrusions comprising the micro-implant group, and from 10 similar patients comprising the J-hook headgear group, were assessed for maxillary central incisor apical root resorption. Measurements before and after orthodontic therapy were also obtained from lateral cephalometric radiographs to calculate incisor horizontal retraction and vertical intrusion distances. Estimated retraction force vectors were calculated in horizontal and vertical directions for both treatment groups. Data analysis employed t-tests and the Pearson correlation test, with α=0.05 for statistical significance. The results showed that when compared with the J-hook group, significantly more apical root resorption shortening of the maxillary central incisors was observed in the micro-implant group (1.27 mm difference, 95% CI=0.70-1.84, P<0.001), which was associated with a significantly larger retraction distance (P=0.004) and a smaller vertical force component (P<0.0001). We are led to conclude that continuous activation of the nickel-titanium coil springs used in the micro-implant group resulted in significantly more apical root resorption shortening and maxillary central incisor retraction than when intermittent J-hook retraction was employed. The employment of continuous duration orthodontic forces presents a risk for increased apical root resorption that requires careful radiographic monitoring.

Gastroesophageal reflux disease and tooth erosion.

The increasing prevalence of gastroesophageal reflux disease (GERD) in children and adults, and of "silent refluxers" in particular, increases the responsibility of dentists to be alert to this potentially severe condition when observing unexplained instances of tooth erosion. Although gastroesophageal reflux is a normal physiologic occurrence, excessive gastric and duodenal regurgitation combined with a decrease in normal protective mechanisms, including an adequate production of saliva, may result in many esophageal and extraesophageal adverse conditions. Sleep-related GERD is particularly insidious as the supine position enhances the proximal migration of gastric contents, and normal saliva production is much reduced. Gastric acid will displace saliva easily from tooth surfaces, and proteolytic pepsin will remove protective dental pellicle. Though increasing evidence of associations between GERD and tooth erosion has been shown in both animal and human studies, relatively few clinical studies have been carried out under controlled trial conditions. Suspicion of an endogenous source of acid being associated with observed tooth erosion requires medical referral and management of the patient as the primary method for its prevention and control.

Implications of oral biofilms in medically at risk persons.

There is the need to understand the composition of oral biofilms so that appropriate preventive and treatment regimens, including using appropriate antimicrobials, can be developed further. Additionally, when the systemic effects from specific microorganisms in oral biofilms are better understood, more targeted preventive treatment options may be recommended for persons at high risk for potential systemic diseases such as cardiovascular disease, and for aspiration pneumonia. Hence, the possible association between periodontopathic microorganisms, and also between cariogenic microorganisms in high caries risk persons, and systemic diseases requires further research involving metagenomic and large well-designed clinical studies. Effective preventive oral care is important for reducing potential systemic diseases.

Oral manifestations of gastroesophageal reflux disease.

Numerous case-control and other studies involving confirmation of gastroesophageal reflux disease (GERD) by esophageal pH-metry and the assessment of dental erosions have shown significant associations between the two conditions in both adults and children. By contrast, when asked to vote on whether GERD may cause dental erosions, only 42% of physicians strongly agreed that such an association existed in adults, and just 12.5% strongly agreed for children, respectively in two global consensus reports. Part of this divergence between the perceptions of physicians and the findings of research publications may reflect a general lack of oral health education during medical training, and cursory oral examinations being made under less-than-ideal conditions. Adequate salivary secretions are essential for the protection of the teeth and the oropharyngeal and esophageal mucosa. The quantity and quality of the saliva require monitoring as many drugs, including several of the proton pump inhibitors (PPIs), can cause hyposalivation. In addition, PPIs do not always result in adequate acid suppression. Therefore, collaboration between physicians and dentists is strongly advocated to prevent or ameliorate possible adverse oral effects from both endogenous and exogenous acids, and to promote adequate saliva production in patients with GERD.

[Report and analysis of periodicals of oral science in China].

OBJECTIVE: To review and analyze the history and current situation of stomatological journals in China from 1949 to 2009. METHODS: The data from journal database, web sites and yearbooks were collected, and the information on Chinese dental journals, national economic indicators and the development in dental disciplines from 1949 to 2009 were obtained. RESULTS: The dental journals numbered one kind, four issues in 1949 and 32 kinds, 204 issues in 2009. China's gross domestic product (GDP) was from 67.9 billion Yuan in 1949 to 30.067 trillion Yuan in 2008. CONCLUSIONS: The quantity of stomatological journals in China has increased remarkably over the past 60 years.

Corrosion behaviour and surface analysis of a Co-Cr and two Ni-Cr dental alloys before and after simulated porcelain firing.

This study evaluated the corrosion behaviour and surface properties of a commercial cobalt-chromium (Co-Cr) alloy and two nickel-chromium (Ni-Cr) alloys [beryllium (Be)-free and Be-containing] before and after a simulated porcelain-firing process. Before porcelain firing, the microstructure, surface composition and hardness, electrochemical corrosion properties, and metal-ion release of as-cast alloy specimens were examined. After firing, similar alloy specimens were examined for the same properties. In both as-cast and fired conditions, the Co-Cr alloy (Wirobond C) showed significantly more resistance to corrosion than the two Ni-Cr alloys. After firing, the corrosion rate of the Be-free Ni-Cr alloy (Stellite N9) increased significantly, which corresponded to a reduction in the levels of Cr, molybdenum (Mo), and Ni in the surface oxides and to a reduction in the thickness of the surface oxide film. The corrosion properties of the Co-Cr alloy and the Be-containing Ni-Cr alloy (ChangPing) were not significantly affected by the firing process. Porcelain firing also changed the microstructure and microhardness values of the alloys, and there were increases in the release of Co and Ni ions, especially for Ni from the Be-free Ni-Cr alloy. Thus, the corrosion rate of the Be-free Ni-Cr alloy increased significantly after porcelain firing, whereas the firing process had little effect on the corrosion susceptibility of the Co-Cr alloy and the Be-containing Ni-Cr alloy.

Effect of three radicular dentine treatments and two luting cements on the regional bond strength of quartz fibre posts.

The purpose was to investigate by push-out tests and scanning electron microscopy (SEM)/energy-dispersive spectroscopy (EDS) the effect, after first acid etching the post space walls, of three radicular dentine treatments on the regional bond strength of quartz fibre posts placed using two heavily filled resin luting cements. The crowns of 39 extracted maxillary central incisors were sectioned transversely 2 mm coronal to the labial cement-enamel junction and the roots endodontically treated. After standardized post space preparations and etching 15 s with 32% phosphoric acid, 36 roots were randomly divided into six equal groups. Quartz fibre posts (D.T. LIGHT-POST) were placed using three radicular dentine treatments (0.9% sodium chloride (NaCl) for 60 s, 10% sodium hypochlorite (NaOCl) for 60 s, 17% ethylenediaminetetraacetic acid (EDTA) for 60 s followed by 5.25% NaOCl for 60 s) and two resin composite luting cements (ONE-STEP PLUS/DUO-LINK; ONE-STEP PLUS/LuxaCore Dual). Transverse segments (S1-S7), 1.00 mm (SD = 0.05 mm) thick, were sectioned from the coronal 8 mm of each root. Push-out bond strength tests were performed on coronal, middle and apical post space segments (S2, S4, S6) at a crosshead speed of 0.5 mm/min. Data were recorded and analyzed using a two-way mixed ANOVA design (a = 0.05). Three segments (S1, S5, S7) from roots in each group were examined using SEM/EDS. After post space preparation, acid etching and using each of the three radicular dentine treatments, the three remaining roots were sectioned longitudinally for SEM observation of the post space walls. At all root segment sites, the mean bond strengths from using 0.9% NaCl were significantly lower than for the other two radicular dentine treatments (P ≤ 0.02), and DUO-LINK cement had significantly higher mean bond strengths than LuxaCore Dual cement (P ≤ 0.01). There was a significant linear trend for reduced bond strengths from coronal to apical post space segments (P < 0.001), which was supported by the SEM/EDS observations of dentine tubule appearance and resin tag formation. Acid etching followed by either 10% NaOCl or 17% EDTA and 5.25% NaOCl dentine treatments of the post spaces provided good adhesion and resin luting cement tag infiltration of dentinal tubules in the coronal and middle segments in particular.

Identifying and reducing risks for potential fractures in endodontically treated teeth.

INTRODUCTION: Although long-term functional survival rates can be high for initial endodontically treated permanent teeth, they are generally more susceptible to fracture than teeth with vital pulps. Tooth extraction is often the consequence of an unfavorable prognosis after coronal and root fractures, but their occurrence in endodontically treated teeth might be reduced by identifying the risks for fracture associated with various operative procedures. METHODS: This article presents an overview of the risk factors for potential tooth fractures in endodontically treated teeth on the basis of literature retrieved from PubMed and selected journal searches. RESULTS: Postendodontic tooth fractures might occur because of the loss of tooth structure and induced stresses caused by endodontic and restorative procedures such as access cavity preparation, instrumentation and irrigation of the root canal, obturation of the instrumented root canal, post-space preparation, post selection, and coronal restoration and from inappropriate selection of tooth abutments for prostheses. CONCLUSIONS: Potential tooth fractures might be reduced by practitioners being aware during dental treatments of controllable and noncontrollable risks.

Fracture resistance after simulated crown lengthening and forced tooth eruption of endodontically-treated teeth restored with a fiber post-and-core system.

PURPOSE: To evaluate the effect of ferrule preparation length on the fracture resistance after simulated surgical crown lengthening and after forced tooth eruption of endodontically-treated teeth restored with a carbon fiber-reinforced post-and-core system. METHODS: 40 extracted endodontically-treated mandibular first premolars were decoronated 1.0 mm coronal to the buccal cemento-enamel junction. The teeth were divided randomly into five equal groups. The control group had no ferrule preparation (Group A). Simulated crown lengthening provided ferrule preparations of 1.0 mm (Group B) and 2.0 mm (Group C). Simulated forced tooth eruption provided ferrule preparations of 1.0 mm (Group D) and 2.0 mm (Group E). After restoration with a carbon fiber post-and-core system, each root was embedded in an acrylic resin block from 2.0 mm apical to the margins of a cast Ni-Cr alloy crown, and loaded at 150 degrees from the long axis in a universal testing machine at a crosshead speed of 1.0 mm/minute until fracture. Data were analyzed using ANOVA with Tukey HSD tests, and Fisher's exact test, with alpha = 0.05. RESULTS: Mean failure loads (kN) for Groups A, B, C, D and E were: 1.13 (SD = 0.15), 1.27 (0.18), 1.02 (0.11), 1.63 (0.14) and 1.92 (0.19), respectively. Significant differences were shown for the effects of treatment method and ferrule length, with significant interaction between these two sources of variation (P < 0.0001). Increased apical ferrule preparation lengths resulted in significantly increased fracture resistance for simulated forced tooth eruption (P < 0.0001), but not for simulated crown lengthening (P > or = 0.24).

Optimum post and tooth root diameters for a cast post-core system.

PURPOSE: To investigate the optimum diameter for the tapered post of a cast alloy post-core system relative to the root diameter, when measured at the root face, that is required to minimize both post and root failures. METHODS: 32 extracted maxillary central incisor teeth were each decoronated perpendicular to the long axis at a point 2.0 mm occlusal to the labial cemento-enamel junction. Following endodontic canal obturation, the teeth were assigned randomly to four equal groups for different diameter tapered post space preparations. Then 1.10, 1.50, 1.70, and 2.00 mm diameter cast Ni-Cr alloy post-cores and complete crowns without ferrules were fabricated. Each root was embedded in a large gypsum stone block and the crown loaded palatally at 135 degrees from the long axis in a universal testing machine at a crosshead speed of 1.0 mm/minute until failure. Results were analyzed using one-way ANOVA with Tukey-Kramer post hoc tests, and Fisher's exact test, with alpha = 0.05 for statistical significance. RESULTS: Mean failure resistance loads were: 0.60, 0.91, 1.00, and 1.38 kN (P < 0.001). All of the 1.10 mm posts failed, without any root fractures. Conversely, none of the 2.00 mm posts failed, but all of the roots fractured. The optimum post to root diameter ratio to minimize failures was approximately 1:4.

Comparative evaluation of micro-implant and headgear anchorage used with a pre-adjusted appliance system.

The aim of this study was to compare and evaluate the anchorage effectiveness of using either micro-implants or extraoral headgear with the McLaughlin-Bennett-Trevisi (MBT) system. Thirty young Chinese adults (14 males and 16 females) aged 18-22 years with anterior bimaxillary protrusion were divided randomly into two equal groups, treated with the MBT system anchored by either micro-implants or headgear. Nine measurements obtained before and after treatment from lateral cephalometric radiographs were assessed for the two groups, using the Mann-Whitney U test with alpha = 0.05 for statistical significance. The maxillary incisors in the micro-implant group were significantly more retracted and intruded, while the lower incisors were more lingually inclined, than in the headgear group. The occlusal and mandibular planes were rotated more counterclockwise in the micro-implant group than in the headgear group (P < 0.05). Compared with headgear anchorage, micro-implant anchorage may counteract clockwise rotation of the occlusal and mandibular planes and result in different final positions for the maxillary and mandibular incisors.

Fracture resistance and microtensile bond strength of maxillary premolars restored with two resin composite inlay systems.

PURPOSE: To compare the in vitro fracture resistance and the microtensile bond strength (muTBS) of premolar teeth restored with two light-cured resin composite inlay systems. METHODS: 50 sound human maxillary premolars were divided randomly into five equal groups. Four groups received mesial-occlusal-distal (MOD) inlay preparations. Restorative treatments comprised: Group 1 (Renew direct resin composite), Group 2 (Renew direct resin composite inlay), Group 3 (Tescera indirect resin composite inlay), Group 4 (non-restored), Group 5 (intact). All teeth were loaded axially until fracture. The same resin-based materials as used in Groups 1-3 were bonded to the superficial coronal dentin of 15 teeth. Beams approximately 1.0 mm x 1.0 mm were prepared and tested in microtensile mode. Results were compared using one-way ANOVA and Tukey's multiple comparison tests. RESULTS: Mean fracture strengths (KN): Group 1, 2.06 (0.76); Group 2, 2.30 (0.49); Group 3, 2.62 (0.68); Group 4, 1.24 (0.44); Group 5, 2.40 (0.71). Group 4 was significantly weaker that the other four groups, P < 0.01. Mean muTBSs (MPa): Group 1, 33.38 (6.24); Group 2, 20.38 (6.24); Group 3, 20.87 (4.62). Group 1 was significantly stronger than the other two groups, P < 0.01.

Translucency and biaxial flexural strength of four ceramic core materials.

OBJECTIVES: To assess the relative translucencies and flexural strengths of four dental restorative ceramic core materials. METHODS: Eight disk specimens (14 mm in diameterx 0.5+/-0.05 mm in thickness) were prepared for each group of four ceramic core materials (IPS Empress 2 dentin, VITA In-Ceram Alumina, VITA In-Ceram Zirconia, Cercon Base Zirconia), according to the manufacturers' instructions. A color meter was used to measure the relative translucencies of the specimens. The biaxial flexure test (ISO 6872) was then used to measure their flexural strengths. Data for relative translucency (0.0-1.0), fracture load (N) and biaxial flexural strength (MPa) were analyzed by one-way ANOVA, followed by Tukey's multiple comparison test for significant findings (alpha = 0.05). RESULTS: For relative translucency: IPS Empress 2 (0.78+/-0.03), VITA In-Ceram Alumina (0.94+/-0.01), VITA In-Ceram Zirconia (1.00+/-0.01), Cercon Base Zirconia (1.00+/-0.01), P<0.0001. For biaxial flexural strength: IPS Empress 2 (355.1+/-25.7), VITA In-Ceram Alumina (514.0+/-49.5), VITA In-Ceram Zirconia (592.4+/-84.7), Cercon Base Zirconia (910.5+/-95.3), P<0.0001. SIGNIFICANCE: IPS Empress 2 and VITA In-Ceram Alumina were significantly more translucent than the two opaque zirconia-containing core materials. IPS Empress 2 was significantly weaker, and Cercon Base Zirconia was significantly stronger, than the other two ceramic core materials.

Up-regulation of multiple proteins and biological processes during maxillary expansion in rats.

BACKGROUND: Maxillary expansion (ME) is a common practice in orthodontics that aims to increase the constricted maxillary arch width. Relapse often occurs, however, and better treatment strategies are needed. In order to develop a more effective method, this study was designed to further examine the process of tissue remodeling during ME, to identify the changes in expression of several proteins of interest, and to clarify the molecular mechanism responsible for tissue remodeling. METHODS: Male Wistar rats were randomly divided into control and ME groups. The rats were euthanized at various intervals over 11 days, and the dissected palates were prepared for histological examination. The structure of the midpalatal sutures changed little during the first three days. Proteins from samples in the ground midpalatal tissues obtained on the third day were subjected to two-dimensional polyacrylamide gel electrophoresis (2-DE) and matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis. Validation of protein expression was performed by Western blot analyses. RESULTS: From day 5, chondrocytes in the inner layer of suture cartilage and osteoblasts at the end of the suture cartilage began to proliferate, and the skeletal matrix increased later adjacent to the cartilage in the ME group. Comparative proteomic analysis showed increases in 22 protein spots present in the ME group. The changes in three proteins closely related to osteogenesis (parathyroid hormone, osteoprotegerin and vimentin) were confirmed by Western blotting. CONCLUSION: Many proteins are over-expressed during ME, and they may play an important role in the remodeling process.

Effect of two fiber post types and two luting cement systems on regional post retention using the push-out test.

OBJECTIVE: To investigate regional root canal push-out bond strengths for two fiber-reinforced post types using two adhesive systems. METHODS: The crowns of 24 recently extracted sound maxillary central incisors were sectioned transversely 2 mm coronal to the labial cemento-enamel junction, and the roots treated endodontically. Following standardized post space preparations, fiber-reinforced posts (C-POST; AESTHETI-PLUS) were placed using two adhesive systems (acid-etch ONE-STEP PLUS/C&B CEMENT; self-adhesive RelyX Unicem), in four equal groups. Push-out bond strength tests were performed at four sites in each root. Results were analyzed using split-plot ANOVA, with a=0.05 for statistical significance. RESULTS: AESTHETI-PLUS quartz fiber-reinforced posts showed significantly higher push-out strengths than C-POST carbon fiber-reinforced posts (P<0.0001). The separate acid-etch adhesive system resulted in significantly higher bond strengths than the self-etch self-adhesive system (P<0.0001). Bond strengths decreased significantly from coronal to apical root canal regions (P<0.0001). SIGNIFICANCE: The quartz fiber-reinforced post placed using the separate acid-etch adhesive system provided significantly better post retention than the carbon fiber-reinforced post placed using the self-etch self-adhesive system.