32^nd Asia Pacific Dental and Oral Health Congress July 23-24, 2018 Sydney, Australia

Amin Lotfi was born in 1994 in Tehran. He entered university at the age of 18 and is now studying dentistry.

Antiresorptive medications are used mainly to treat patients with osteoporosis or different cancers with bone involvement such as multiple myeloma, breast carcinoma, and prostate carcinoma for bone metastasis prevention. In the last decade, taking these medications has caused many problems for patients and their dentists. Therefore, it is imperative for all dentists to be aware of the side effects of taking these drugs and caution is required in dental procedures, such as tooth extraction. The purpose of this case report is to present a case of bisphosphonate-related osteonecrosis of mandible with cutaneous sinus affecting a 64-year-old female with past medical history of breast cancer.

Reaserch Fellow
Dentistry school of Chounbuk National University, South Korea

Background: Extracellular DNA (eDNA) is a component of the biofilm matrix, which also includes microbial cells, exopolysaccharides, and proteins. Although many studies have examined eDNA, there is little information available regarding Streptococcus mutans eDNA. Methods: To characterize S. mutans eDNA, we cultured the bacteria for 1 to 24 h in medium with 1% sucrose or 1% glucose. We identified eDNA by using polymerase chain reaction and used DNA-binding dye, SYBR green I to measure the amount of eDNA. Results: We found that S. mutans eDNA has some differences from S. mutans genomic DNA, and that eDNA is secreted at an early growth stage (ï‚£ 1 h postinoculation). S. mutans produced more eDNA in the supernatant and less eDNA in the pellet in 1% glucose than in 1% sucrose. Although S. mutans cultured in 1% sucrose had more colony forming units (CFUs), the pH values were higher and the CFU-normalized eDNA levels were lower compared to S. mutans cultured in 1% glucose. DNase treatment removed eDNA and significantly reduced the total dry weight (2.6 fold in 1% glucose and 1.4 fold in 1% sucrose). Conclusions: These results indicate that S. mutans produces different levels of eDNA in different media, and that eDNA is an important component aggregator in S. mutans biofilms.

Chen-Ting Hsu graduated from School of Dentistry, Taipei Medical University in 2015. He is a graduate student at School of Dentistry, National Taiwan University and majors in Operative Dentistry.

Magnetic attachments have been widely used as stud attachments for implant-retained overdenture rehabilitation. The connection of polymethylmethacrylate (PMMA) with magnetic assemblies relies on the mechanical undercut. However, detachment of PMMA from magnetic assemblies is a frequent problem. Polydopamine has been reported to have high affinity to metal. As the magnetic attachments are enveloped by stainless steel, the aim of this study was to enhance the bond strengths between stainless steel and PMMA using polydopamine and compare with alloy primer (10-MDP, Kuraray) and quick monomer (4-META, Sun Medical). Stainless steel discs (5.5 mm in diameter and 2.5 mm in thickness, Aichi Steel Corp.) and PMMA (Unifast Trad, GC Dental Corp.) were used. For polydopamine group, the discs were immersed in dopamine solution (2 mg of dopamine per milliliter of 10 mM tris, pH 8.5) for 24 h at room temperature. MDP and 4-META were applied on stainless steel discs using microbrush. Subsequently, the discs were mounted in molds and PMMA (powder/liquid 2:1) was filled. They were placed in 60oC oven for 6 h. The shear bond strengths were measured using Instron at crosshead speed of 1 mm/min. The debonded surfaces were examined using X-ray photoelectron spectroscopy (XPS). The results showed that 10-MDP group exhibited the highest bond strengths (9.8±1.6 MPa) followed by 4-META group (3.5±0.4 MPa) and polydopamine group (1.9±1.6 MPa). XPS analysis revealed that the major fracture surfaces took place at PMMA and coating materials (polydopamine, 10-MDP, 4-META).

Professor Toshiyuki Kawakami is Chairman of Hard Tissue Pathology Unit, Department of Hard Tissue Research, Matsumoto Dental University Graduate School of Oral Medicine. He is the Director of Matsumoto Dental University Liberally, Director of Japanese Society of Oral Pathology, Director of Society of Hard Tissue Generative Biology, Academic Council of Japanese Society of Pathology, Japanese Association of Oral Biology and Japanese Stomatological Society. He has been serving as the Senior Editorial Adviser of the Journal of Hard Tissue Biology (ISSN 1341-7649, Online ISSN 1880-828X), published by the Hard Tissue Biology Network Association.

Objective: In this study, cholesterin was implanted in the subcutaneous tissue in mice to induce the formation of cholesterol granuloma. Histological　and immunohistochemical (IHC) and immunofluorescent (IFHC) examinations were carried out to determine the type and source of cells. Materials and Methods: The GFP bone marrow transplanted-model mice were embedded 10 mg of cholesterin into the subcutaneously tissues. After from 2 weeks and till 6 months, the embedded tissues were examined by histopathology.Furyher, GFP cell mechanism was further assessed by IHC using double IFHC staining with GFP-S100A4, GFP-Runx2, GFP-CD31. Results: At 2 weeks, cholesterin was replaced partly by granulation tissues. The majority of cells in the granulation tissues were macrophages and foreign body giant cells and the center consists of small amount of fibroblasts, collagen fibers and capillaries. At 3 to 6 months, the cholesterin was mostly substituted by fibrous tissues consisting mainly of fibroblasts and collagen fibers with some macrophages and foreign body giant cells. Immunohistochemistry revealed that macrophages and foreign body giant cells were positive to GFP and CD68 although the fibroblasts and capillaries in the outer portion of cholesterol granulomas were GFP negative. Some spindle shape fibroblasts were also GFP positive. Immunofluorescent double staining revealed that cells lining the blood vessels were both positive to GFP and CD31 indicating that those were endothelial cells and were actually derived from the transplanted bone marrow cells. Conclusion: The results suggest that macrophages, foreign body giant cells as well as fibroblasts and capillary endothelial cells are bone marrow derived mesenchymal cells.

Uchikawa graduated from School of Matsumoto Dental University in 2015. He enrolled in the graduate school of Matsumoto Dental University . He continues the experiments of oral health as a postdoctoral fellow at Matsumoto Dental University.

The maintenance of oral function affects the health of the whole body. Therefore it is very important to leave many tooth until it becomes old. Then we investigated environmental factors and methods of cleaning teeth to give the number of the residual teeth in the elderly. Forty-four elderly people (23 men and 21 female, mean age: 73.7±7.28) were enrolled in this study. The number of remaining teeth, age, quantity of stimulated saliva, stimulated salivary buffering capacity, oral bacteria (mutans streptococci), PCR (plaque control record), the number of brushing per day, brushing time, using of supporting tool and the fluorine application were investigated and demanded those correlations. Furthermore, we divided participants into two groups, more than 20 or 20 teeth and less than 20 teeth. These result of the nine factors was compared between two groups. The number of the remaining teeth correlated with buffering capacity, using of supporting tool or fluorine application (Spearman’s correlation coefficient: p＜0.05). In the 2 groups, the significant difference was recognized in buffering ability, SM bacteria quantity, the number of brushing times and fluorine application (Mann-Whitney U test : p＜0.05 ). It was thought that to remain teeth in elderly, a high buffering capacity or less SM bacteria in saliva is necessary. In addition, it was suggested that it is important to use supporting tool for cleaning on the teeth and receive fluorine application in a lifestyle.

Masahito Shoumura is an associate professor of Department of Pediatric dentistry at Matsumoto Dental University.He also work as a part-time lecturer at Department of Sports Dentistry of Tokyo Dental University. He earned a degree of a doctor of dentistry from the Graduate School of Oral Medicine at Matsumoto Dental University.He is a specialist and councilor of Japanese Society of Pediatric Dentistry now.

Objective: In our previous examination, the experimentally induced periodontal polyp in mice was examined the cytological dynamics of the lesion by immunohistochemistry using Green Fluorescence Protein bone marrow-transplanted model mice. Our data indicated that the cells in granulation tissue are mainly from migration of undifferentiated mesenchymal cells of the bone marrow, and differentiate into the tissue-specified cells. Materials and Methods: In the present examination using the same methods using GFP-BMT model mice, the crown of maxillary left first molar of the mouce using ½ round bur to create a perforation of floor of the dental pulp. The regions were examined by histopathology and immunohistochemistry. Results: Histopathological examination revealed the results suggest that fibroblasts, periodontal ligament fibroblasts and blood vessels in granulation tissue were derived from transplanted-bone marrow cells. Thus, essential growth of granulation tissue in periodontal polyp was caused by the migration of undifferentiated mesenchymal cells derived from bone marrow, which differentiated into fibroblasts and later on differentiated into other cells in response to injury.　The fibroblasts with some round cells and blood vessels were proliferated in the granulation tissue, experimental ranges from at 2 weeks to 6 months. Immunohistochemical staining of Notch1 revealed that the protein was expressed in almost spindle-shaped cells. The result suggests that the periodontal ligament fibroblasts in granulation tissue were expressed Notch1 protein. Conclusion: Further examination is needed. However, the data strongly suggests that the cell differentiation within the periodontal polyp was controlled by Notch signaling.

Mashael AlHadlaq is a student at King Saud University,Saudi Arabia

Introduction Tempromandibullar disorders are the second most common musculoskeletal conditions that cause pain and disability. The pathogenesis of TMD is multifactorial, involving biological, psychological and behavioral factors. Several studies suggested that stress and TMD are related, according to (Korszun et al.,2017) that indicated “Patients appearing for treatment with chronic facial pain show a high comorbidity with other stress-associated syndromes”. TMD prevalence is 20 – 30% of adult populations, and more common in females. TMD can be screened by clinical examinations, or by using “Fonseca’s Anamnestic Index” (FAI). Methodology Anonymous electronic questioner was distributed through social media to several female dental colleges in Riyadh. The questioner included two parts, first one to assess the severity and signs and symptoms of TMD using “Fonseca’s anamnestic index” (FAI). The second part to measure anxiety level using “Zung Anxiety Self-Assessment Scale” (SAS). The analysis was done using SPSS, applying Chi square tests. Results The cross-tabulation of the academic year with (FAI) resulted in a P-value of 0.405 indicating no significance. The cross-tabulation of the academic year with (SAS) resulted in a P-value of 0.093 indicating a slight significance. The cross-tabulation of Fonseca’s index results with Zung’s anxiety resulted in a P-value of 0.000 indicating a high significance. Conclusion Our results showed that anxiety is highly related to TMD and we concluded that 62.8% of female dental students has anxiety of different levels.

Furuta graduated from School of Dentistry at Asahi University in 1990. He graduated from Graduate School of Matsumoto Dental University and acquired Ph.D in 2017. He has his private dental clinic in Shiga prefecture. He continues the experiments of oral pain as a postdoctoral fellow at Matsumoto Dental University.

The pain causes the stress, and the continued pain reduces quality of life. It is known that the sense of pain decreases by listening to music. Our previous study showed that rhythmical music is more effective to increase the pain threshold than classical music (Vivaldi) and Japanese ballad. Then we examined the effects of favorite music on the pain perception of forearm. Thirty subjects (men:15, women:15, age: 13-85 years old) were investigated for pain thresholds on the forearm by using pain vision PS-2100 (Nipro) which the intensity of electric stimulation gradually increases. They choose their favorite music from You Tube. The measurement of pain threshold was performed for each three times when they wore headphone and were listening favorite music or without music. The thresholds of pain with favorite music (55.7±52.2μA) were significantly higher than those without music (40.3±31.3μA) (Wilcoxon test: p<0.0001). And the men’s thresholds were significantly higher than women at the both situation, with music (Mann-Whitney test: p<0.01) and without music (p<0.05). The kinds of the music that they chose were classical music (2 people), Japanese pop music (7 people), Chinese pop music (2 people) ballads (12 people), rock music (2 people) and Japanese folk (5 people). The present findings suggest that the pain perception might be strongly effected by listening to favorite music.

Soo-Kyung Bae has completed his PhD at the age of 31 years from Pusan National University (South Korea) and postdoctoral studies from Kyoto University (Japan) and NIH (USA). She is the head of Dep. Dental Phamacology of Pusan National University. She has published more than 20 papers in reputed journals and has been interested in the interaction between cells and microenvironment.

The anti-aging activities of melatonin, a hormone secreted by the pineal gland, have been reported in senescence-accelerated mouse models and several types of cells. However, the effects and mechanisms of melatonin on the senescence of human dental pulp cells (HDPCs) remain unknown. Here, we found that the melatonin markedly inhibited the senescent characteristics of HDPCs after exposed to hydrogen peroxide (H2O2), including the increase in senescence-associated β-galactosidase (SA-β-gal)-positive HDPCs and the upregulation of p21 protein, an indicator for senescence. In addition, melatonin attenuated H2O2-stimulated phosphorylation of c-Jun N-terminal kinase (JNK). Furthermore, H2O2-induced senescence of HDPCs was significantly suppressed by a specific inhibitor of JNK signaling, as measured by SA-beta-gal staining assay. Taken together, these results reveal that melatonin antagonizes premature senescence of HDPCs via JNK pathway. Thus, melatonin might have the therapeutic potential to prevent stress-induced premature senescence, possibly correlated with the development of dental pulp diseases, and to maintain teeth health across the life span.

Lina AlHudaithy, 23 years old. A 2018 dental graduate from King Saud University, Riyadh, Saudi Arabia. Graduated with a first-class honor. Grateful that I graduated from one of the top 50 colleges worldwide based on QS world universities rankings. Passionate in doing extra-curriculum activities such as community dental public health programs, and researches. I’m looking forward to expose myself to as much international conferences as possible to get more experience and to learn more so I can serve my specialty the best.