Archives of oral biology

Publications in this journal

• Article: Determination of the functional space for fluid movement in the rat dentinal tubules using fluorescent microsphere.

  Ying Li, Hideharu Ikeda, Hideaki Suda
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  ABSTRACT: OBJECTIVES: The size of the functional space available for hydrodynamic fluid movement between cellular components and the walls of dentinal tubules has not yet been investigated. We attempted to measure the space using small diameter fluorescent microspheres. METHODS: The coronal enamel of 144 rat molars was removed to expose the dentine, which was acid-etched. Fluorescent microspheres of different diameters (0.02-4.0μm) were applied to the exposed dentine for 60min before the rat jaws were cut into cryostat sections. The distribution and fluorescent intensities of the fluorescent microspheres were examined with confocal laser scanning microscope and analyzed using image analysis software. RESULTS: Microspheres with a diameter of 2.0-4.0μm were detected only on the surface of the cavities. A small number of microspheres with a diameter of 1.0μm accumulated primarily in the outer third of the dentine. Microspheres with a diameter of 0.2-0.5μm were found in the outer and middle thirds of the dentine. Microspheres with a diameter of 0.02-0.1μm accumulated in the middle and occasionally inner thirds of the dentine. Some of the microspheres measuring 0.02-0.04μm in diameter reached the dental pulp. CONCLUSIONS: The dentinal tubules in the inner third of the rat coronal dentine may have a space less than 0.1μm through which dentinal fluid can move, despite outward tapering of the dentinal tubules. Retrograde tapering may increase the pressure in the inner third of the dentine layer, and this elevated pressure may contribute to mechanical deformation of the content in the dentinal tubules.
  Archives of oral biology 07/2013; 58(7):780-787.
• Article: Adenovirus encoding BMP-7 immobilized on titanium surface exhibits local delivery ability and regulates osteoblast differentiation in vitro.

  Shenyuan Chen, Jiahua Yang, Hang Wang, Yonglie Chao, Chaoliang Zhang, Jiefei Shen, Ping Zhang
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  ABSTRACT: OBJECTIVE: The local delivery of growth factors such as bone morphogenetic protein-7 (BMP-7) into the tissues around dental implants may improve their osseointegration. We have designed a new method of attaching BMP-7 to a titanium surface and assessed both the retention of the BMP-7 and its effect on osteoblast differentiation. DESIGN: Adenoviral vector expressing BMP-7 was attached to dental titanium discs by hexon-specific antibodies in a type I collagen-avidin gel. FITC-labelled secondary antibody was used to measure the continuing adherence of the coating after repeated rinsing. Osteoblasts were harvested and seeded on the titanium discs. Gene transduction efficiency and targeting ability were assessed after 24h. Surface morphology was observed by SEM. Cell proliferation and alkaline phosphatase (ALP) activities were measured. RESULTS: The anti-adenohexon antibody adhered strongly to the collagen-avidin gels. BMP-7 gene expression was localized precisely to cells growing on the gels bound by the hexon-specific antibody. Osteoblasts on the titanium containing Ad-BMP-7 had a higher ALP activity than those without Ad-BMP-7. CONCLUSIONS: This study describes a novel technique for the precise attachment of BMP-7 to titanium surfaces. The process may enhance the osseointegration of dental implants.
  Archives of oral biology 06/2013;
• Article: Periodontal disease in HIV-infected adults in the HAART era: Clinical, immunological, and microbiological aspects.

  Lucio Souza Gonçalves, Barbara Mulatinho Lopo Gonçalves, Tatiana Vasconcellos Fontes
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  ABSTRACT: The introduction of highly active antiretroviral therapy (HAART) has decreased the incidence and prevalence of several oral manifestations such as oral candidiasis, hairy leukoplakia, and Kaposi's sarcoma in HIV-infected patients. Regarding periodontal disease the findings are not clear. This disease represents a group of chronic oral diseases characterized by infection and inflammation of the periodontal tissues. These tissues surround the teeth and provide periodontal protection (the gingival tissue) and periodontal support (periodontal ligament, root cementum, alveolar bone). Clinical, immunological, and microbiological aspects of these diseases, such as linear gingival erythema (LGE), necrotizing periodontal diseases (NPD) (necrotizing ulcerative gingivitis [NUG], necrotizing ulcerative periodontitis [NUP] and necrotizing stomatitis), and chronic periodontitis, have been widely studied in HIV-infected individuals, but without providing conclusive results. The purpose of this review was to contribute to a better overall understanding of the probable impact of HIV-infection on the characteristics of periodontal infections.
  Archives of oral biology 06/2013;
• Article: The oxidant scavenging capacity of the oral Mycoplasma salivarium.

  J D Kornspan, I Ginsburg, S Rottem
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  ABSTRACT: OBJECTIVE: Mycoplasma salivarium is a human oral potential pathogen that preferentially resides in dental plaques and gingival sulci. It has been suggested that this organism may play an etiological role in inflammatory processes in the oral cavity. The aim of this work was to determine whether M. salivarium possesses a potent oxidant scavenging capacity (OSC). DESIGN: The OSC of M. salivarium was quantified by a highly sensitive luminal-dependent chemiluminescence assay in the presence of cocktails that induced a constant flux of luminescence resulting from the generation of peroxide, hydroxyl radical (cocktail A) and NO, superoxide and peroxynitrites (cocktail B). RESULTS: M. salivarium markedly reduced oxidative stress by scavenging both free reactive oxygen and nitrogen species. The OSC of M. salivarium was much higher than that of other Mycoplasma species. Most of M. salivarium OSC was confined to the cytosolic fraction and was markedly increased in the presence of tannic acid, red blood cells or mucin. The cytosolic OSC of M. salivarium was heat stable and not affected by sodium azide or prolonged proteolysis. However, it was markedly decreased upon dialysis, suggesting that the major reducing activity is not enzymatic but rather, a low molecular weight compound(s). CONCLUSIONS: The ability of M. salivarium to scavenge oxidants may play a role in the survival and pathogenicity of this microorganism. The enhanced OSC of M. salivarium in the presence of tannic acid, red blood cells or mucin might have a significant importance to assess complex interactions with polyphenols from nutrients, salivary proteins and red blood cells extravasated from injured capillaries during infection and inflammation in oral tissues.
  Archives of oral biology 06/2013;
• Article: Clinical and genetic evaluation of a Chinese family with isolated oligodontia.

  Han Qin, Hong-Zhi Xu, Kun Xuan
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  ABSTRACT: OBJECTIVES: Oligodontia is defined as the congenital absence of 6 or more permanent teeth excluding the third molar. Tooth agenesis may be classified as syndromic/non-syndromic and as familial/sporadic. To date, more than 300 genes have been found to be involved in tooth development, but only a few of these genes, such as MSX1, PAX9 and AXIN2, are related to the condition of non-syndromic oligodontia. The objective of the present work was to investigate the disease-causing gene of non-syndromic oligodontia in a Han Chinese family and analyse the pathogenesis of mutations that result in oligodontia. DESIGN: We examined all individuals of the oligodontia family by clinical and radiographic examinations. Based on the clinical manifestations, the candidate genes MSX, PAX9 and AXIN2 were selected to analyse and screen for mutations. RESULTS: The clinical evaluation suggested that the family might show non-syndromic oligodontia. DNA sequencing of the MSX1 gene revealed two mutations in the two patients with oligodontia: a heterozygotic silent mutation, c.348C>T (P.Gly116=), in exon 1 and a homozygotic deletion of 11 nucleotides (c.469+56delins GCCGGGTGGGG) in the intron. However, the silent mutation and the deletion mutation were thought to be known polymorphisms (rs34165410 and rs34341187) by bioinformatics analysis. We did not detect any mutations in the PAX9 and AXIN2 genes of oligodontia patients. CONCLUSION: Our finding suggests that identified polymorphisms (c.348C>T and c.469+56delins GCCGGGTGGGG) may be responsible for the oligodontia phenotype in this Chinese family, but the association requires further study.
  Archives of oral biology 05/2013;
• Article: The induction expression of human β-defensins in gingival epithelial cells and fibroblasts.

  Jiarong Liu, Xingyan Du, Jie Chen, Li Hu, Lili Chen
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  ABSTRACT: OBJECTIVE: The gingival epithelial cells and fibroblasts can produce antimicrobial peptides when stimulated by inflammatory cytokines. The purpose of the present study was to test whether gingival keratinocytes and gingival fibroblasts respond differently to inflammatory cytokine activation. This will enable us to understand the chronic inflammatory response in the process of periodontal disease. DESIGN: Gingival keratinocytes and fibroblasts were isolated and treated with different concentrations of IL-1β and quantitative real-time PCR was performed to evaluate the induced expressions of hBD-1, hBD-2 and hBD-3. The induced response was compared between the gingival epithelial cells and fibroblasts. The inhibitors of p38 protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) were applied to explore the molecular mechanism during the induction of hBDs in both cells. RESULTS: The results showed that the hBDs expressions were found to be induced by different concentrations of IL-1β, but with several differences between gingival epithelial cells and fibroblasts. The hBDs mRNA expression in gingival fibroblasts was more sensitive compared with keratinocytes to different concentrations of IL-1β. The hBD-1 and hBD-3 expressions in these two cells were down-regulated by IL-1β and hBD-2 expression was up-regulated. The inflammatory cytokine IL-1β had dual effect on hBDs expression. CONCLUSIONS: The gingival epithelial cells and fibroblasts respond differently to the inflammatory cytokine IL-1β which indicated different roles played by the two cells in the host defense. The dual effect of IL-1β on hBDs expression may contribute to the defensins down-regulation in periodontal disease.
  Archives of oral biology 05/2013;
• Article: Antifungal properties of the anti-hypertensive drug: Aliskiren.

  Gunderao Hanumantrao Kathwate, S Mohan Karuppayil
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  ABSTRACT: OBJECTIVES: Aliskiren, the first in a new class of orally active renin inhibitors, is licensed for the treatment of hypertension. It inhibits plasma renin activity directly, thereby reducing generation of angiotensin II. In this study, we have explored the anti-Candida properties of aliskiren. METHODS: Candida albicans was cultured in the presence or absence of aliskiren for various time periods. Subsequently, inhibition of growth, germtube formation, adhesion, early/matured biofilm development and secreted aspartic protease (SAP) activity were studied. RESULTS: When cultured in the presence of aliskiren, Candida showed significant reduction in the activity of aspartic proteases. Aliskiren impaired in vitro growth of C. albicans. It also affected two other virulence factors, germtube and adhesion. There is reduction in early and matured biofilm when treated with aliskiren. CONCLUSIONS: Aliskiren could be considered as a candidate for antifungal drug development.
  Archives of oral biology 05/2013;
• Article: Increased oxidative stress biomarkers in the saliva of Down syndrome patients.

  Tomoko Komatsu, Yoon Duckyoung, Ayumi Ito, Kenji Kurosawa, Yojiro Maehata, Tomoko Kubodera, Masakazu Ikeda, Masaichi-Chnag-Il Lee
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  ABSTRACT: OBJECTIVE: The DNA oxidation byproduct 8-hydroxy-2'-deoxyguanosine (8-OHdG) is a well-known biomarker used to evaluate oxidative stress. We previously reported that the generation of reactive oxygen species (ROS) is increased in cultured gingival fibroblasts (GF) from patients with Down syndrome (DS). Thus, the aim of this study was to evaluate 8-OHdG as a marker of oxidative stress in saliva of DS patients. MATERIALS AND METHODS: The study group consisted of DS patients (66 patients; age range 1-62 years) and systemically healthy control subjects (71 subjects; age range 4-58 years). Periodontal status was judged based on standard measurements of probing depth (PD) and gingival index (GI). The salivary levels of 8-OHdG were determined using an enzyme-linked immunosorbent assay. RESULTS: The mean of PD and GI values were not significantly different between young (1-12 years) patients with DS (DS-1) and controls (C-1) or between adult (30-62 years) patients with DS (DS-2) and controls (C-2). There were statistically significant positive correlations between the salivary 8-OHdG levels and GI in the DS-1, DS-2 and C-2 groups, but not in the C-1. There were also statistically significant positive correlations between salivary 8-OHdG levels and PD in the DS-2 and C-2 groups, but not in the DS-1 or C-1 groups. The salivary levels of 8-OHdG of DS-1 and DS-2 groups were significantly higher than in the C-l and C-2 groups, respectively. CONCLUSIONS: These results suggest that progressive oxidative stress occurred in DS patients. Oxidative stress may contribute to the clinical features of DS, particularly to the progressive periodontitis characteristic of early ageing.
  Archives of oral biology 05/2013;
• Article: Pigmentation of the oral mucosa by PCB poisoning in Yusho patients.

  Goro Kawasaki, Izumi Yoshitomi, Souichi Yanamoto, Shin-Ichi Yamada, Akio Mizuno, Masahiro Umeda
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  ABSTRACT: OBJECTIVES: Toxins, such as PCBs, dramatically affect patients even decades after exposure. Although 40 years have passed since the accidental poisoning with polychlorinated biphenyl (PCB) in Western Japan in 1968, high concentrations of PCBs are still detected in the serum of the "Yusho" (oil disease) patients. In this study, an epidemiological examination was carried out to reveal the prevalence of the oral pigmentation and blood concentrations of PCBs and polychlorinated quaterphenyl (PCQ) in Yusho victims. DESIGN: We performed a group examination of patients (Yusho victims) from 2004 to 2006, including 72 Yusho victims and 15 control subjects. The oral examination was performed by two oral and maxillofacial surgeons. The serum concentrations of PCB and PCQ were determined using gas chromatography; blood samples from Yusho victims were analyzed for PCB and PCQ by saponification in 1M NaOH ethanol solution, extraction with n-hexane column chromatography on silica gel, and then gas chromatography with electron capture detection. RESULTS: The mean Yusho victim's serum PCB and PCQ concentrations were 3.3ppb and 0.9ppb, respectively. In controls, these were 0.7ppb and 0ppb, respectively. Oral pigmentation was observed in 24 out of 72 Yusho patients. In controls, oral pigmentation was observed in one out of 15 persons. Oral pigmentation was most frequently observed in the buccal mucosa, followed by gingival mucosa. The blood concentration of PCB in Yusho patients with oral pigmentations was significantly higher than that in Yusho patients without oral pigmentation. CONCLUSION: These results indicated that PCB-related compounds may be responsible for the higher prevalence of oral pigmentation in Yusho victims, even though a long time has passed since the Yusho poisoning accident.
  Archives of oral biology 05/2013;
• Article: Immunocompetent cell level as a diagnostic reference for pulpal pathosis of primary teeth.

  Leyla Durutürk, Saziye Sarı, Ali Sengül
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  ABSTRACT: OBJECTIVE: The present study was designed to measure changes in the level of immunocompetent cells as healthy pulp becomes inflamed in order to evaluate the use of CD4+/CD8+ and B/CD3+ lymphocyte ratios as a diagnostic reference for pulpal pathosis in primary teeth pulp. DESIGN: Based on clinical and radiographic examinations, 113 carious and non-carious primary teeth were grouped as healthy teeth, teeth with reversible pulpitis and teeth with irreversible pulpitis. Following dental extraction, pulp samples were collected from all teeth, and 81 of the samples were found to be suitable for flow-cytometric analysis of lymphocyte subset. Kolmogorov-Smirnov's test, One-way ANOVA and Tukey's Post Hoc tests were used for statistical analysis. RESULTS: Statistical analysis revealed no increases in the mean percentages of T, B and CD4+ lymphocytes in inflamed pulp when compared to healthy pulp. However, both CD8+ and NK cell numbers decreased in line with progressive inflammation. Whereas the CD4+/CD8+ ratios increased in accordance with the severity of pulpitis, B/T ratios remained unaffected. CONCLUSIONS: Immunocompetent cell levels did not change in line with progressive inflammation; therefore, the use of CD4+/CD8+ and B/CD3+ lymphocyte ratios cannot be used as a diagnostic reference for pulpal pathosis in primary teeth.
  Archives of oral biology 05/2013;
• Article: In vivo study of the initial bacterial adhesion on different implant materials.

  A Al-Ahmad, M Wiedmann-Al-Ahmad, A Fackler, M Follo, E Hellwig, M Bächle, C Hannig, J-S Han, M Wolkewitz, R Kohal
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  ABSTRACT: OBJECTIVE: Biofilm formation on implant materials plays a major role in the aetiology of periimplantitis. The aim of this study was to examine in vivo the initial bacterial adhesion on six different implant materials. METHODS: The implant materials Ti-m, TiUnite(®), ZiUnite(®), ATZ-m, ATZ-s, TZP-A-m were tested using bovine enamel slabs as controls. All materials, fixed on splint systems, were examined after 30min and 120min of oral exposure. DAPI staining was used for quantitative analysis of the initially adherent microorganisms. Initial adherent microorganisms were visualised by fluorescence In situ-hybridisation (FISH) and quantified by confocal laser scanning microscopy (CLSM). The targets of the oligonucleotide probes were Eubacteria, Veillonella spp., Fusobacterium nucleatum, Actinomyces naeslundii and Streptococcus spp. RESULTS: DAPI analysis showed that increasing the time of oral exposure resulted in an increasing amount of initial adherent bacteria. The highest level of colonisation was on ZiUnite(®), with the lowest occurring on the bovine enamel, followed by Ti-m. This early colonisation correlated significantly with the surface roughnesses of the materials. FISH and CLSM showed no significant differences relating to total bacterial composition. However, Streptococcus spp. was shown to be the main colonisers on each of the investigated materials. CONCLUSION: it could be shown that within an oral exposure time of 30min and 120min, despite the salivary acquired pellicle initial biofilm formation is mainly influenced directly or indirect by the material surface topography. Highly polished surfaces should minimise the risk of biofilm formation, plaque accumulation and possibly periimplantitis.
  Archives of oral biology 05/2013;
• Article: Assessment of thickness and function of masticatory and cervical muscles in adults with and without temporomandibular disorders.

  Paulinne Junqueira Silva Andresen Strini, Polyanne Junqueira Silva Andresen Strini, Taís de Souza Barbosa, Maria Beatriz Duarte Gavião
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  ABSTRACT: OBJECTIVE: The aim of this study was to evaluate the maximal bite force (MBF), electromyographic (EMG) activity and thickness of the masseter, anterior part of the temporalis and sternocleidomastoid (SCM) muscles in a group of young adults with and without temporomandibular disorders (TMDs). DESIGN: Nineteen individuals comprised the TMD group (6 males/13 females, aged 25.4±3.8 years), classified based on the Research Diagnostic Criteria for TMD (RDC/TMD), and 19 comprised the control group (6 males/13 females, aged 24.1±3.6 years). The MBF was determined with a transducer placed between the dental arches at the first molars level (N). The muscles were evaluated bilaterally at rest and during maximal voluntary clenching (MVC) by assessing EMG activity and performing ultrasonography (USG). The mean values of these measures for both sides of the mouth were used. The normality of the distributions was assessed by the Shapiro-Wilks test. Variables between groups and genders were compared using two-way factorial ANOVA test and correlated using the Spearman coefficient (α=0.05). Unpaired t test was used to compare variables between TMD subgroups. Logistic regression analysis was used to identify the variables associated with the presence of TMD. RESULTS: MBF, EMG and USG data were similar among clinical groups and among TMD subgroups. The thickness of masseter and SCM muscles in the relaxed and clenching states were significantly higher in males than females. On the other hand, the EMG of the temporalis muscle in the rest state was significantly higher in females than males. Additionally, the MBF was positively correlated with the USG characteristics of masseter and SCM muscles, as well as with the EMG activity of masseter and temporalis muscles in the TMD group. In this group, there was also a positive correlation between the thickness of the masseter muscle and its activity. On the other hand, the thickness of the SCM muscle was negatively correlated with its activity. A lower MBF was independently associated with the presence of TMD. CONCLUSIONS: Subjects with TMD exhibited similar values of MBF, thickness and electrical activity of masticatory and cervical muscles when compared with controls; positive correlations observed between these variables may suggest a muscular alteration in TMD patients and a co-activation of masticatory and cervical muscles during mandibular movement. This fact may also be confirmed by the negative association between bite forces and presence of TMD.
  Archives of oral biology 05/2013;
• Article: Endocannabinoids mediate hyposalivation induced by inflammogens in the submandibular glands and hypothalamus.

  J P Prestifilippo, V A Medina, C E Mohn, P A Rodriguez, J C Elverdin, J Fernandez-Solari
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  ABSTRACT: OBJECTIVE: The aim of this study was to investigate the factors that could participate on salivary glands hypofunction during inflammation and the participation of endocannabinoids in hyposalivation induced by the presence of inflammogens in the submandibular gland (SMG) or in the brain. DESIGN: Salivary secretion was assessed in the presence of inflammogens and/or the cannabinoid receptor antagonist AM251 in the SMG or in the brain of rats. At the end of the experiments, some systemic and glandular inflammatory markers were measured and histopathological analysis was performed. RESULTS: The inhibitory effect observed 1h after lipopolysaccharide (LPS, 50μg/50μl) injection into the SMG (ig) was completely prevented by the injection of AM251 (5μg/50μl) by the same route (P<0.05). The LPS (ig)-induced increase in PGE2 content was not altered by AM251 (ig), while the glandular production of TNFα induced by the endotoxin (P<0.001) was partially blocked by it. Also, LPS injection produced no significant changes in the wet weight of the SMG neither damage to lipid membranes of its cells, nor significant microscopic changes in them, after hispopathological analysis, compared to controls. Finally, TNFα (100ng/5μl) injected intracerebro-ventricularly (icv) inhibited methacholine-induced salivary secretion evaluated 30min after (P<0.01), but the previous injection of AM251 (500ng/5μl, icv) prevented completely that effect. CONCLUSION: We conclude that endocannabinoids mediate the hyposialia induced by inflammogens in the SMG and in the brain. The hypofunction would be due to changes on signalling pathway produced by inflammatory compounds since anatomical changes were not observed.
  Archives of oral biology 05/2013;
• Article: Histologic evaluation and immunohistochemical localization of STRO-1 and BMP-4 in rat immature teeth: A comparison between vital and induced pulp necrosis.

  Daiana Elisabeth Böttcher, Roberta Kochenborger Scarparo, Eraldo Luiz Batista, Anna Christina Medeiros Fossati, Fabiana Soares Grecca
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  ABSTRACT: OBJECTIVE: To assess histological features and the expression of STRO-1 and BMP-4 in dental pulp and periapical tissues in vital or necrotic rat immature teeth. DESIGN: The lower left first molars of male Wistar rats ageing four weeks (n=24) had their pulps exposed to the oral environment for 3, 6, 9 and 12 weeks (animals ageing 7, 10, 13 and 16 weeks-old, respectively; n=24). The right lower first molars served as control untouched teeth. After sample harvesting the jaws were dissected and processed for histology and immunodetection of STRO-1 and BMP-4. RESULTS: Necrotic teeth had root development arrested, while control animals showed development of dental tissues. Immunohistochemistry showed that detection of BMP-4 was restricted to vital pulps. For both groups, STRO-1 expression was evident around blood vessels walls. Neither BMP-4 nor STRO-1 was observed in the apical papilla region. CONCLUSION: STRO-1-positive precursor cells were not detected in the apical papilla. BMP-4 expression has not been detected during infection.
  Archives of oral biology 05/2013;
• Article: Underlying protective mechanism of α1-adrenoceptor activation against irradiation-induced damage in rat submandibular gland.

  Bin Xiang, Xiu-Xiu Li, Fu-Yin Zhang
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  ABSTRACT: OBJECTIVES: Damage to salivary gland after radiotherapy for head and neck malignant tumours can lead to irreversible oral complaints, which severely impair quality of life. The protective effect of α1-adrenoceptor activation on the salivary glands after irradiation has previously been demonstrated. However, the exact mechanism remains unclear. In this study, we investigated the underlying cytoprotective mechanism of α1-adrenoceptor activation in rat submandibular glands after irradiation. STUDY DESIGN: Rats were locally irradiated using a linear accelerator in the head and neck region with a dose of 20Gy. After irradiation, phenylephrine (5mg/kg) was injected intraperitoneally for 7 successive days and the submandibular glands were then collected. The antiapoptotic effect of phenylephrine on the gland was examined by TUNEL, the proliferative cellular nuclei antigen (PCNA) was determined by immunohistochemistry, and the activation of c-Jun N-terminal kinase (JNK) was detected by Western blot. RESULTS: The irradiation only group showed severe atrophy, increased apoptosis, enhanced cell proliferation, and the phosphorylation of JNK was markedly increased by 26.89% (P<0.05), compared to the control. The phenylephrine-treated group, however, showed remarkably alleviated atrophy, decreased apoptosis, and further increased cell proliferation, and the phosphorylation of JNK was markedly decreased by 36.00% (P<0.05), compared to the irradiation only group. CONCLUSIONS: The data showed that the underlying protective mechanism of α1-adrenoceptor activation in irradiated gland might be related to improved cell proliferation, inhibited cell apoptosis, and depressed activation of JNK. It could be helpful in protecting salivary glands against irradiation damage.
  Archives of oral biology 05/2013;
• Article: Dynamics of oral microbial community profiling during severe early childhood caries development monitored by PCR-DGGE.

  Ye Tao, Yan Zhou, Yong Ouyang, Huancai Lin
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  ABSTRACT: OBJECTIVE: To monitor the longitudinal changes in oral microbial diversity of children with severe early childhood caries (S-ECC) compared to caries free (CF) controls. METHODS: Dental plaque samples of 12 children in each group at 8, 14, 20, 26 and 32 months of age were analysed. Total microbial genomic DNA was isolated from each sample, and PCR-denaturing gradient gel electrophoresis (DGGE) analyses were carried out. RESULTS: The number of bands was significantly higher in the CF group (18.17±4.91 bands) than in the S-ECC group (14.54±5.56 bands) at 32 months of age (P<0.05). A total of 21 genera were identified in all subjects, and there were no significant differences between the two groups at genus level. DGGE profiles showed that most of the clusters were constructed from one individual over time in the both groups. CONCLUSIONS: The onset of S-ECC is accompanied by a decrease in microbial diversity. The overall composition of the microbiota is highly similar within an individual over time.
  Archives of oral biology 05/2013;
• Article: Oral lichen planus: Focus on etiopathogenesis.

  Márcia Rodrigues Payeras, Karen Cherubini, Maria Antonia Figueiredo, Fernanda Gonçalves Salum
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  ABSTRACT: Lichen planus is a chronic mucocutaneous inflammatory disease, which frequently affects the oral mucosa of white females over 40 years old. Its aetiology remains uncertain and the pathogenesis is still the object of much speculation. The present paper presents the most well known antigens, and describes the action of different cells and proteins associated with the development of that disease, as well as the possible agents involved with its malignant transformation. Different external agents, especially virus, and internal agents, like stress, and the heat shock protein antigen expression, associated or not, can alter the basal keratinocytes of the oral mucosa making them susceptible to apoptosis by CD8(+) cytotoxic T cell as well as activate matrix metalloproteinase and mast cell degranulation, which produce a great range of inflammatory mediators and cytokines determining the clinical onset of the disease. Regarding carcinogenesis, since it is a complex process and presents multifactorial origin, it is believed that there may be a synergism between intrinsic, such as inflammation mediators, and extrinsic agents (tobacco, alcohol, viral infections) for the OLP malignant transformation to occur. However, further studies are needed to better understand the origin, pathogenesis and process of malignant transformation of OLP.
  Archives of oral biology 05/2013;
• Article: Influence of a bioceramic root end material and mineral trioxide aggregates on fibroblasts and osteoblasts.

  Ines Willershausen, Thomas Wolf, Adrian Kasaj, Veronika Weyer, Brita Willershausen, Benjamin Briseño Marroquin
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  ABSTRACT: OBJECTIVE: The biocompatibility of materials used in endodontic treatment is of high importance, because they can come in contact with periradicular tissues and there is a risk of possible systemic toxicity. The aim of the present study was to investigate the in vitro reaction to a bioceramic based root end material in comparison to mineral trioxide aggregates (MTA) as the established gold standard. DESIGN: The root end materials grey MTA Angelus (GMTA), white MTA Angelus (WMTA), ProRoot MTA, and EndoSequence Root Repair Material (ERRM) were incubated with human periodontal ligament fibroblasts and osteoblasts (10(4)cells/ml) for up to 96h. Cell proliferation (RFU) was determined by means of the Alamar Blue assay. In addition, fluorescence staining was carried out to visually monitor cell growth and morphology. RESULTS: For most of the observational time period of up to 96h, there was no statistically significant difference between the proliferation rates of the control cells and those in contact with ERRM. In contrast, the mineral trioxide based materials caused from 24 to 96h significantly lower proliferation rates in comparison to the controls (p<0.001). For proliferation rates of cells in contact with MTAs and ERRM significant differences were observed throughout the whole observation time for the osteoblasts, but only up to 24h for the human periodontal ligament fibroblasts. CONCLUSION: Within the limits of this study the results suggest that the bioceramic root end material is biocompatible, but needs to be investigated in clinical studies before it can be recommended as retrograde sealer in endodontic practice.
  Archives of oral biology 05/2013;
• Article: The interleukin-10 gene promoter polymorphisms are associated with cyclosporin A-induced gingival overgrowth in renal transplant patients.

  Yixi Luo, Yiming Gong, Youcheng Yu
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  ABSTRACT: OBJECTIVE: Interleukin-10 (IL-10) is an anti-inflammatory cytokine whose genetic polymorphisms are associated with the production of IL-10 and the susceptibility to periodontal diseases. The aim of this study was to investigate the possible association of IL-10 single nucleotide polymorphisms (SNPs) and cyclosporin A (CsA)-induced gingival overgrowth (GO) in renal transplant patients in a Chinese population, taking into account subgingival microbiota as additional variables. MATERIAL AND METHODS: A total of 202 patients were dichotomized into two groups: 122 with GO and 80 without GO. The IL-10-1082 SNP, -819 SNP and -592 SNP were measured using an allele-specific PCR method. The levels of subgingival bacteria were measured by real-time PCR. Genotype and allele frequencies were analyzed using the Chi-square test and logistic regression analysis. RESULTS: The frequency of IL-10-819TT (-592AA) genotype was statistically higher in patients with GO than that in patients without GO (P<0.05). Multiple logistic regression analysis demonstrated that the prevalence of GO is not dependent on age, gender, and pharmacological variables, being significantly associated with the carriers of ATA haplotype (OR=2.425, 95%CI=1.214-4.845, P=0.012). Moreover, ATA positive carriers in the GO group presented significantly higher levels of Porphyromonas gingivalis and Treponema denticola than those negative carriers. CONCLUSIONS: Our results show that IL-10-819TT (-592AA) genotype and ATA halpotype are associated with susceptibility to CsA-induced GO. Meanwhile, ATA haplotype is associated with a higher detection of P. gingivalis and T. denticola in GO patients, and may increase the risk of developing GO.
  Archives of oral biology 05/2013;
• Article: Effects of growth hormone and ultrasound on mandibular growth in rats: MicroCT and toxicity analyses.

  Imran Khan, Ayman O El-Kadi, Tarek El-Bialy
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  ABSTRACT: It has been shown by previous studies that mandibular growth can be enhanced by the systemic administration of recombinant growth hormone (rGH) and/or local application of therapeutic low intensity pulsed ultrasound (LIPUS). The purpose of this study was to determine if local injection of rGH and application of LIPUS to the temporomandibular joint (TMJ) would synergistically enhance mandibular growth. In an animal study, the effect of rGH, LIPUS, and combination of rGH and LIPUS on male Sprague-Dawley rats was observed. Mandibular growth was evaluated by measuring total hemimandibular and condylar bone volume and bone surface area as well as condylar bone mineral density (BMD) after 21 days on dissected rats' mandibles using micro-computed tomography (MicroCT). The expression of c-jun mRNA extracted from the liver of each of these rats was also quantified by real-time polymerase chain reaction to evaluate possible systemic effect of local rGH administration. Significant growth stimulation was observed in the mandibular and condylar bone of the animals treated with rGH, LIPUS, and rGH/LIPUS combined when compared with the control group. Bone volume, surface area, condylar bone mineral density, and c-jun expression were also compared between the treatment groups and the control in the liver. The results suggest that mandibular growth may be enhanced by injection of rGH or LIPUS application. The current study although showed synergetic effect of rGH and LIPUS application in increasing mandibular condylar head length, there was no significant changes in mandibular bone volume using both treatments together when compared to the two individual treatments. Moreover, combined rGH and LIPUS decreased condylar bone mineral density than each treatment separately. Future research could be directed to investigate the effects of different rGH doses and/or different LIPUS exposures parameters on lower jaw growth.
  Archives of oral biology 04/2013;