AIMTo evaluate the effects of maxillary sinus floor elevation by a tissue-engineered bone complex of beta-tricalcium phosphate (beta-TCP) and autologous osteoblasts in dogs.

METHODOLOGYAutologous osteoblasts from adult Beagle dogs were cultured in vitro. They were further combined with beta-TCP to construct the tissue-engineered bone complex. 12 cases of maxillary sinus floor elevation surgery were made bilaterally in 6 animals and randomly repaired with the following 3 groups of materials: Group A (osteoblasts/beta-TCP); Group B (beta-TCP); Group C (autogenous bone) (n=4 per group). A polychrome sequential fluorescent labeling was performed post-operatively and the animals were sacrificed 24 weeks after operation for histological observation.

RESULTSOur results showed that autologous osteoblasts were successfully expanded and the osteoblastic phenol-types were confirmed by ALP and Alizarin red staining. The cells could attach and proliferate well on the surface of the beta-TCP scaffold. The fluorescent and histological observation showed that the tissue-engineered bone complex had an earlier mineralization and more bone formation inside the scaffold than beta-TCP along or even autologous bone. It had also maximally maintained the elevated sinus height than both control groups.

CONCLUSIONPorous beta-TCP has served as a good scaffold for autologous osteoblasts seeding. The tissue-engineered bone complex with beta-TCP and autologous osteoblasts might be a better alternative to autologous bone for the clinical edentulous maxillary sinus augmentation.

Alkaline Phosphatase ; analysis ; Alveolar Ridge Augmentation ; methods ; Animals ; Anthraquinones ; Biocompatible Materials ; therapeutic use ; Biomarkers ; analysis ; Bone Substitutes ; therapeutic use ; Bone Transplantation ; pathology ; Calcification, Physiologic ; physiology ; Calcium Phosphates ; therapeutic use ; Cell Adhesion ; physiology ; Cell Proliferation ; Dogs ; Fluorescent Dyes ; Guided Tissue Regeneration, Periodontal ; methods ; Maxilla ; surgery ; Maxillary Sinus ; surgery ; Models, Animal ; Osteoblasts ; transplantation ; Osteogenesis ; physiology ; Random Allocation ; Tissue Engineering ; methods ; Tissue Scaffolds ; Transplantation, Autologous

AIMTo clarify the role of PTCH in patients with NBCCS-related and non-sydromic keratocystic odontogenic tumors.

METHODOLOGYMutation analysis was undertaken in 8 sporadic and 4 NBCCS-associated KCOTs.

RESULTSFour novel and two known mutations were identified in 2 sporadic and 3 syndromic cases, two of which being germline mutations (c.2179delT, c.2824delC) and 4 somatic mutations (c.3162dupG, c.1362-1374dup, c.1012 C>T, c.403C>T).

CONCLUSIONOur findings suggest that defects of PTCH are associated with the pathogenesis of syndromic as well as a subset of non-syndromic KCOTs.

Adolescent ; Adult ; Amino Acid Sequence ; Basal Cell Nevus Syndrome ; genetics ; Chromatography, High Pressure Liquid ; Codon, Nonsense ; genetics ; Codon, Terminator ; genetics ; Conserved Sequence ; genetics ; Cytosine ; Exons ; genetics ; Female ; Frameshift Mutation ; genetics ; Gene Duplication ; Germ-Line Mutation ; genetics ; Guanine ; Humans ; Male ; Middle Aged ; Mutation ; genetics ; Mutation, Missense ; genetics ; Odontogenic Tumors ; genetics ; Patched Receptors ; Patched-1 Receptor ; Receptors, Cell Surface ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Deletion ; genetics ; Syndrome ; Threonine ; genetics ; Thymine

AIMTo characterize the odontogenic capability of apical bud and phenotypical change of apical bud cells (ABCs) in different microenvironment.

METHODOLOGYIncisor apical bud tissues from neonatal SD rat were dissected and transplanted into the renal capsules to determine their odontogenic capability. Meanwhile ABCs were cultured and purified by repeated differential trypsinization. Then ABCs were cultured with conditioned medium from developing apical complex cells (DAC-CM). Immunocytochemistry, reverse transcriptase polymerase chain reaction (RT-PCR) and scanning electron microscope (SEM) were performed to compare the biological change ofABC treated with or without DAC-CM.

RESULTSFirst we confirmed the ability of apical bud to form crown-like structure ectopically. Equally important, by using the developing apical complex (DAC) conditioned medium, we found the microenvironment created by root could abrogate the "crown" features of ABCs and promote their proliferation and differentiation.

CONCLUSIONABCs possess odontogenic capability to form crown-like tissues and this property can be affected by root-produced microenvironment.

Ameloblasts ; cytology ; Amelogenin ; analysis ; Animals ; Animals, Newborn ; Cell Culture Techniques ; Cell Differentiation ; physiology ; Cell Proliferation ; Cell Transplantation ; Culture Media, Conditioned ; Dental Enamel Proteins ; analysis ; Epithelial Cells ; cytology ; Immunohistochemistry ; Incisor ; cytology ; embryology ; Keratin-14 ; analysis ; Kidney ; surgery ; Microscopy, Electron, Scanning ; Odontogenesis ; physiology ; Phenotype ; Rats ; Rats, Sprague-Dawley ; Reverse Transcriptase Polymerase Chain Reaction ; Tooth Apex ; cytology ; Tooth Crown ; cytology ; Tooth Germ ; cytology

AIMTo evaluate the effect of single or dual field irradiation (IR) with the same dose on damage to miniature pig parotid glands.

METHODOLOGYSixteen miniature pigs were divided into two IR groups (n=6) and a control group (n=4). The irradiation groups were subjected to 20 Gy X-radiation to one parotid gland using single-field or dual-field modality by linear accelerator. The dose-volume distributions between two IR groups were compared. Saliva from parotid glands and blood were collected at 0, 4, 8 and 16 weeks after irradiation. Parotid glands were removed at 16 weeks to evaluate tissue morphology.

RESULTSThe irradiation dose volume distributions were significantly different between single and dual field irradiation groups (t=4.177, P=0.002), although dose volume histogramin (DVH) indicated the equal maximal dose in parotid glands. Saliva flow rates from IR side decreased dramatically at all time points in IR groups, especially in dual field irradiation group. The radiation caused changes of white blood cell count in blood, lactate dehydrogenase and amylase in serum, calcium, potassium and amylase in saliva. Morphologically, more severe radiation damage was found in irradiated parotid glands from dual field irradiation group than that from single field irradiation group.

CONCLUSIONData from this large animal model demonstrated that the radiation damage from the dual field irradiation was more severe than that of the single field irradiation at the same dose, suggesting that dose-volume distribution is an important factor in evaluation of the radiobiology of parotid glands.

Amylases ; analysis ; blood ; radiation effects ; Animals ; Blood Platelets ; radiation effects ; Calcium ; analysis ; radiation effects ; Erythrocyte Count ; Erythrocytes ; radiation effects ; L-Lactate Dehydrogenase ; blood ; radiation effects ; Leukocyte Count ; Leukocytes ; radiation effects ; Male ; Models, Animal ; Organ Size ; radiation effects ; Parotid Gland ; pathology ; radiation effects ; Potassium ; analysis ; radiation effects ; Radiation Dosage ; Random Allocation ; Saliva ; chemistry ; radiation effects ; Secretory Rate ; radiation effects ; Swine ; Swine, Miniature ; Time Factors

Dental Implantation ; education ; trends ; Education, Dental ; trends ; Humans ; Japan ; Societies, Dental ; trends ; Specialties, Dental ; trends

Tooth loss compromises human oral health. Although several prosthetic methods, such as artificial denture and dental implants, are clinical therapies to tooth loss problems, they are thought to have safety and usage time issues. Recently, tooth tissue engineering has attracted more and more attention. Stem cell based tissue engineering is thought to be a promising way to replace the missing tooth. Mesenchymal stem cells (MSCs) are multipotent stem cells which can differentiate into a variety of cell types. The potential MSCs for tooth regeneration mainly include stem cells from human exfoliated deciduous teeth (SHEDs), adult dental pulp stem cells (DPSCs), stem cells from the apical part of the papilla (SCAPs), stem cells from the dental follicle (DFSCs), periodontal ligament stem cells (PDLSCs) and bone marrow derived mesenchymal stem cells (BMSCs). This review outlines the recent progress in the mesenchymal stem cells used in tooth regeneration.
Adult Stem Cells ; physiology ; Bone Marrow Cells ; cytology ; Dental Papilla ; cytology ; Dental Pulp ; cytology ; Dental Sac ; cytology ; Humans ; Mesenchymal Stromal Cells ; physiology ; Multipotent Stem Cells ; physiology ; Periodontal Ligament ; cytology ; Regeneration ; physiology ; Tissue Engineering ; Tooth ; physiology ; Tooth, Deciduous ; cytology

The oral carriage rate of Candida in healthy humans ranges from 40% to 60%. However for a prolonged period, the oral candidal prevalence in humans was documented essentially using data from studies in the West as their prevalence in inhabitants in different regions of the world, including Asia was not known. Yet, recent reports from a number of studies indicate the quality, quantity and prevalence of oral yeasts differ between Asia and other regions for reason that are still unclear. This mini review on such data from Asian studies on oral carriage of Candida provides another intriguing facet of the behavior of this ubiquitous yeast.
Areca ; Asian Continental Ancestry Group ; Candida ; classification ; isolation & purification ; Cohort Studies ; Colony Count, Microbial ; HIV Infections ; microbiology ; Humans ; Leprosy ; microbiology ; Mouth ; microbiology

AIMTo elucidate the genetic basis for the pronounced resistance that the oral pathogen, Porphyromonas gingivalis (P. gingivalis), exhibits towards the cationic antimicrobial peptide, polymyxin B.

METHODOLOGYA genetic screen of P. gingivalis clones generated by a Tn4400'-based random insertion mutagenesis strategy was performed to identify bacteria harboring novel genetic mutations that render P. gingivalis susceptible to killing by the cationic antimicrobial peptide, polymyxin B (PMB, 50 microg x mL(-1)).

RESULTSP. gingivalis (ATCC 33277) is unusually resistant to the cationic antimicrobial peptide, PMB at relatively high concentrations (200 microg x mL(-1)). Approximately 2,700 independent Tn4400'-derived mutants of P. gingivalis were examined for increased sensitivity to PMB killing at a relatively low dose (50 microg x mL(-1)). A single PMB-sensitive mutant was obtained in this phenotypic screen. We determined that the Tn4400' transposon was integrated into the gene encoding the lipid A 4'-phosphatase, PGN_0524, demonstrating that this insertion event was responsible for its increased susceptibility of this clone to PMB-dependent killing. The resulting mutant strain, designated 0524-Tn4400', was highly sensitive to PMB killing relative to wild-type P. gingivalis, and exhibited the same sensitivity as the previously characterized strain, 0524KO, which bears a genetically engineered deletion in the PGN_0524 locus. Positive ion mass spectrometric structural (MALDI-TOF MS) analyses revealed that lipid A isolates from 0524-Tn4400' and 0524KO strains displayed strikingly similar MALDI-TOF MS spectra that were substantially different from the wildtype P. gingivalis lipid A spectrum. Finally, intact 0524-Tn4400' and 0524KO mutant bacteria, as well as their corresponding LPS isolates, were significantly more potent in stimulating Toll-like receptor 4 (TLR4)-dependent E-selectin expression in human endothelial cells relative to intact wild-type P. gingivalis or its corresponding LPS isolate.

CONCLUSIONThe combined molecular evidence provided in this report suggests that PGN_0524, a lipid A 4'-phosphatase, is the sole genetic element conferring the ability of the periodontopathogen, P. gingivalis, to evade the killing activity of cationic antimicrobial peptides, such as PMB. These data strongly implicate PGN_0524 as a critical virulence factor for the ability of P. gingivalis to evade front-line host innate defenses that are dependent upon cationic antimicrobial peptide activity and TLR 4 sensing.

Anti-Bacterial Agents ; pharmacology ; Chromosome Mapping ; DNA Transposable Elements ; genetics ; Drug Resistance, Bacterial ; genetics ; E-Selectin ; analysis ; immunology ; Endothelial Cells ; immunology ; microbiology ; Gene Deletion ; Humans ; Lipid A ; analysis ; immunology ; Lipopolysaccharides ; analysis ; immunology ; Mutagenesis, Insertional ; genetics ; Open Reading Frames ; genetics ; Phosphoric Monoester Hydrolases ; genetics ; physiology ; Polymyxin B ; pharmacology ; Porphyromonas gingivalis ; enzymology ; genetics ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ; Toll-Like Receptor 4 ; analysis ; immunology ; Virulence Factors ; physiology

Salivary analysis can be used to assess the severity of caries. Of the known salivary proteins, a paucity of information exists concerning the role of proteinase 3 (PR3), a serine protease of the chymotrypsin family, in dental caries. Whole, unstimulated saliva was collected from children with varying degrees of active caries and tested using a Human Protease Array Kit and an enzyme-linked immunosorbent assay. A significantly decreased concentration of salivary PR3 was noted with increasing severity of dental caries (P<0.01); a positive correlation (r=0.87; P<0.01; Pearson's correlation analysis) was also observed between salivary pH and PR3 concentration. In an antibacterial test, a PR3 concentration of 250 ng·mL⁻¹ or higher significantly inhibited Streptococcus mutans UA159 growth after 12 h of incubation (P<0.05). These studies indicate that PR3 is a salivary factor associated with the severity of dental caries, as suggested by the negative relationship between salivary PR3 concentration and the severity of caries as well as the susceptibility of S. mutans to PR3.
Child ; Dental Caries ; enzymology ; Female ; Humans ; Male ; Myeloblastin ; metabolism ; Saliva ; enzymology

Sub-gingival anaerobic pathogens can colonize an implant surface to compromise osseointegration of dental implants once the soft tissue seal around the neck of an implant is broken. In vitro evaluations of implant materials are usually done in monoculture studies involving either tissue integration or bacterial colonization. Co-culture models, in which tissue cells and bacteria battle simultaneously for estate on an implant surface, have been demonstrated to provide a better in vitro mimic of the clinical situation. Here we aim to compare the surface coverage by U2OS osteoblasts cells prior to and after challenge by two anaerobic sub-gingival pathogens in a co-culture model on differently modified titanium (Ti), titanium-zirconium (TiZr) alloys and zirconia surfaces. Monoculture studies with either U2OS osteoblasts or bacteria were also carried out and indicated significant differences in biofilm formation between the implant materials, but interactions with U2OS osteoblasts were favourable on all materials. Adhering U2OS osteoblasts cells, however, were significantly more displaced from differently modified Ti surfaces by challenging sub-gingival pathogens than from TiZr alloys and zirconia variants. Combined with previous work employing a co-culture model consisting of human gingival fibroblasts and supra-gingival oral bacteria, results point to a different material selection to stimulate the formation of a soft tissue seal as compared to preservation of osseointegration under the unsterile conditions of the oral cavity.
Acid Etching, Dental ; methods ; Alloys ; chemistry ; Bacterial Adhesion ; physiology ; Bacteriological Techniques ; Biofilms ; Cell Adhesion ; physiology ; Cell Culture Techniques ; Cell Line, Tumor ; Cell Movement ; physiology ; Ceramics ; chemistry ; Coculture Techniques ; Dental Alloys ; chemistry ; Dental Etching ; methods ; Dental Implants ; microbiology ; Dental Materials ; chemistry ; Dental Polishing ; methods ; Humans ; Osseointegration ; physiology ; Osteoblasts ; physiology ; Porphyromonas gingivalis ; physiology ; Prevotella intermedia ; physiology ; Surface Properties ; Titanium ; chemistry ; Yttrium ; chemistry ; Zirconium ; chemistry